1
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Kwon H, McClain KR, Kragskow JGC, Staab JK, Ozerov M, Meihaus KR, Harvey BG, Choi ES, Chilton NF, Long JR. Coercive Fields Exceeding 30 T in the Mixed-Valence Single-Molecule Magnet (Cp iPr5) 2Ho 2I 3. J Am Chem Soc 2024; 146:18714-18721. [PMID: 38924484 DOI: 10.1021/jacs.4c06250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
Mixed-valence dilanthanide complexes of the type (CpiPr5)2Ln2I3 (CpiPr5 = pentaisopropylcyclopentadienyl; Ln = Gd, Tb, Dy) featuring a direct Ln-Ln σ-bonding interaction have been shown to exhibit well-isolated high-spin ground states and, in the case of the Tb and Dy variants, a strong axial magnetic anisotropy that gives rise to a large magnetic coercivity. Here, we report the synthesis and characterization of two new mixed-valence dilanthanide compounds in this series, (CpiPr5)2Ln2I3 (1-Ln; Ln = Ho, Er). Both compounds feature a Ln-Ln bonding interaction, the first such interaction in any molecular compounds of Ho or Er. Like the Tb and Dy congeners, both complexes exhibit high-spin ground states arising from strong spin-spin coupling between the lanthanide 4f electrons and a single σ-type lanthanide-lanthanide bonding electron. Beyond these similarities, however, the magnetic properties of the two compounds diverge. In particular, 1-Er does not exhibit observable magnetic blocking or slow magnetic relaxation, while 1-Ho exhibits magnetic blocking below 28 K, which is the highest temperature among Ho-based single-molecule magnets, and a spin reversal barrier of 556(4) cm-1. Additionally, variable-field magnetization data collected for 1-Ho reveal a coercive field of greater than 32 T below 8 K, more than 6-fold higher than observed for the bulk magnets SmCo5 and Nd2Fe14B, and the highest coercive field reported to date for any single-molecule magnet or molecule-based magnetic material. Multiconfigurational calculations, supported by far-infrared magnetospectroscopy data, reveal that the stark differences in magnetic properties of 1-Ho and 1-Er arise from differences in the local magnetic anisotropy of the lanthanide centers.
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Affiliation(s)
| | - K Randall McClain
- US Navy, Naval Air Warfare Center, Weapons Division, Research Department, Chemistry Division, China Lake, California 93555, United States
| | - Jon G C Kragskow
- Department of Chemistry, The University of Manchester, Manchester M13 9PL, U.K
| | - Jakob K Staab
- Department of Chemistry, The University of Manchester, Manchester M13 9PL, U.K
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | | | - Benjamin G Harvey
- US Navy, Naval Air Warfare Center, Weapons Division, Research Department, Chemistry Division, China Lake, California 93555, United States
| | - Eun Sang Choi
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Nicholas F Chilton
- Department of Chemistry, The University of Manchester, Manchester M13 9PL, U.K
- Research School of Chemistry, The Australian National University, Canberra, ACT 2601, Australia
| | - Jeffrey R Long
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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2
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Alessio M, Paran GP, Utku C, Grüneis A, Jagau TC. Coupled-cluster treatment of complex open-shell systems: the case of single-molecule magnets. Phys Chem Chem Phys 2024; 26:17028-17041. [PMID: 38836327 PMCID: PMC11186456 DOI: 10.1039/d4cp01129e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 05/22/2024] [Indexed: 06/06/2024]
Abstract
We investigate the reliability of two cost-effective coupled-cluster methods for computing spin-state energetics and spin-related properties of a set of open-shell transition-metal complexes. Specifically, we employ the second-order approximate coupled-cluster singles and doubles (CC2) method and projection-based embedding that combines equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) with density functional theory (DFT). The performance of CC2 and EOM-CCSD-in-DFT is assessed against EOM-CCSD. The chosen test set includes two hexaaqua transition-metal complexes containing Fe(II) and Fe(III), and a large Co(II)-based single-molecule magnet with a non-aufbau ground state. We find that CC2 describes the excited states more accurately, reproducing EOM-CCSD excitation energies within 0.05 eV. However, EOM-CCSD-in-DFT excels in describing transition orbital angular momenta and spin-orbit couplings. Moreover, for the Co(II) molecular magnet, using EOM-CCSD-in-DFT eigenstates and spin-orbit couplings, we compute spin-reversal energy barriers, as well as temperature-dependent and field-dependent magnetizations and magnetic susceptibilities that closely match experimental values within spectroscopic accuracy. These results underscore the efficiency of CC2 in computing state energies of multi-configurational, open-shell systems and highlight the utility of the more cost-efficient EOM-CCSD-in-DFT for computing spin-orbit couplings and magnetic properties of complex and large molecular magnets.
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Affiliation(s)
- Maristella Alessio
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
- Institute for Theoretical Physics, TU Wien, Wiedner Hauptstraße 8-10/136, 1040 Vienna, Austria
| | | | - Cansu Utku
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
| | - Andreas Grüneis
- Institute for Theoretical Physics, TU Wien, Wiedner Hauptstraße 8-10/136, 1040 Vienna, Austria
| | - Thomas-C Jagau
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
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3
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Zeng M, Ruan Z, Wu S, Tong M. Field-Induced Slow Magnetic Relaxation in Mononuclear Cobalt(II) Complexes Decorated by Macrocyclic Pentaaza Ligands. Molecules 2024; 29:2810. [PMID: 38930875 PMCID: PMC11206533 DOI: 10.3390/molecules29122810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 06/04/2024] [Accepted: 06/08/2024] [Indexed: 06/28/2024] Open
Abstract
Two cobalt(II) complexes [CoL1](OTf)2 (1, L1 = 6,6''-di(anilino)-4'-phenyl-2,2':6',2''-terpyridine) and [CoL2](OTf)2·MeOH (2, L2 = 6,6''-di(N,N-dimethylamino)-4'-phenyl-2,2':6',2''-terpyridine) were synthesized and characterized. Crystal structure analyses showed that the spin carries were coordinated by five N atoms from the neutral pentaaza ligands, forming distorted trigonal bipyramidal coordination environments. Ab initio calculations revealed large easy-axial anisotropy in complexes 1 and 2. Magnetic measurements suggest that complexes 1 and 2 are field-induced single-molecule magnets, whose relaxations are mainly predominated by Raman and direct processes.
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Affiliation(s)
| | | | - Siguo Wu
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, China; (M.Z.); (Z.R.); (M.T.)
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4
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Logallo A, Maddock LCH, Mu M, Gravogl L, Jin N, Peñas-Defrutos MN, Meyer K, García-Melchor M, Hevia E. Unlocking the Metalation Applications of TMP-powered Fe and Co(II) bis(amides): Synthesis, Structure and Mechanistic Insights. Angew Chem Int Ed Engl 2024; 63:e202402907. [PMID: 38563772 DOI: 10.1002/anie.202402907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/19/2024] [Accepted: 04/02/2024] [Indexed: 04/04/2024]
Abstract
Typified by LiTMP and TMPMgCl.LiCl, (TMP=2,2,6,6-tetramethylpiperidide), s-block metal amides have found widespread applications in arene deprotonative metalation. On the contrary, transition metal amides lack sufficient basicity to activate these substrates. Breaking new ground in this field, here we present the synthesis and full characterisation of earth-abundant transition metals M(TMP)2 (M=Fe, Co). Uncovering a new reactivity profile towards fluoroarenes, these amide complexes can promote direct M-H exchange processes regioselectively using one or two of their basic amide arms. Remarkably, even when using a perfluorinated substrate, selective C-H metalation occurs leaving C-F bonds intact. Their kinetic basicity can be boosted by LiCl or NBu4Cl additives which enables formation of kinetically activated ate species. Combining spectroscopic and structural studies with DFT calculations, mechanistic insights have been gained on how these low polarity metalation processes take place. M(TMP)2 can also be used to access ferrocene and cobaltocene by direct deprotonation of cyclopentadiene and undergo efficient CO2 insertion of both amide groups under mild reaction conditions.
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Affiliation(s)
- Alessandra Logallo
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Lewis C H Maddock
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Manting Mu
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin College Green, Dublin, Ireland
| | - Lisa Gravogl
- Department of Chemistry and Pharmacy, Inorganic Chemistry Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058, Erlangen, Germany
| | - Na Jin
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
| | - Marconi N Peñas-Defrutos
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin College Green, Dublin, Ireland
- IU CINQUIMA, Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, 47071, Valladolid, Spain
| | - Karsten Meyer
- Department of Chemistry and Pharmacy, Inorganic Chemistry Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058, Erlangen, Germany
| | - Max García-Melchor
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin College Green, Dublin, Ireland
| | - Eva Hevia
- Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland
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5
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Cui HH, Xu H, Zhang T, Chen Q, Luo S, Wang M, Wang J, Chen L, Zhang M, Tang Y. Magnetic Anisotropy and Relaxation in Four-Coordinate Cobalt(II) Single-Ion Magnets with a [Co IIO 4] Core. Inorg Chem 2024; 63:9050-9057. [PMID: 38709957 DOI: 10.1021/acs.inorgchem.4c00008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
A mononuclear four-coordinate Co(II) complex with a [CoIIO4] core, namely, PPN[Li(MeOH)4][Co(L)2] (1) (PPN = bis(phosphoranediyl)iminium; H2L = perfluoropinacol), has been studied by X-ray crystallography, magnetic characterization, and theoretical calculations. This complex presents a severely distorted coordination geometry. The O-Co-O bite angle is 83.42°/83.65°, and the dihedral twist angle between the O-Co-O chelate planes is 55.6°. The structural distortion results in a large easy-axis magnetic anisotropy with D = -104(1) cm-1 and a transverse component with |E| = +4(2) cm-1. Alternating current (ac) susceptibility measurements demonstrate that 1 exhibits slow relaxation of magnetization at zero static field. However, the frequency-dependent out-of-phase (χ"M) susceptibilities of 1 at 0 Oe do not show a characteristic maximum. Upon the application of a dc field or the dilution with a diamagnetic Zn matrix, the quantum tunneling of magnetization (QTM) process can be successfully suppressed. Notably, after dilution with the Zn matrix, the obtained sample exhibits a structure different from that of the pristine complex. In this altered sample, the asymmetric unit does not contain the Li(MeOH)4+ cation, resulting in an O-Co-O bite angle of 86.05° and a dihedral twist angle of 75.84°, thereby leading to an approximate D2d symmetry. Although such differences are not desirable for magnetic studies, this study still gives some insights. Theoretical calculations reveal that the D parameter is governed by the O-Co-O bite angle, in line with our previous report for other tetrahedral Co(II) complex with a [CoIIN4] core. On the other hand, the rhombic component is found to increase as the dihedral angle deviates from 90°. These findings provide valuable guidelines for fine-tuning the magnetic properties of Co(II) complexes.
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Affiliation(s)
- Hui-Hui Cui
- School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, China
| | - Hongjuan Xu
- School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, China
| | - Tengkun Zhang
- School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, China
| | - Qiukai Chen
- School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, China
| | - Shuchang Luo
- School of Chemical Engineering, Guizhou University of Engineering Science, Bijie 551700, China
| | - Miao Wang
- School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, China
| | - Jin Wang
- School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, China
| | - Lei Chen
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
| | - Mingxing Zhang
- School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, China
| | - Yanfeng Tang
- School of Chemistry and Chemical Engineering, Nantong University, Nantong 226019, China
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6
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Braun J, Powell AK, Unterreiner AN. Gaining Insights into the Interplay between Optical and Magnetic Properties in Photoexcited Coordination Compounds. Chemistry 2024:e202400977. [PMID: 38693865 DOI: 10.1002/chem.202400977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/19/2024] [Accepted: 04/30/2024] [Indexed: 05/03/2024]
Abstract
We describe early and recent advances in the fascinating field of combined magnetic and optical properties of inorganic coordination compounds and in particular of 3d-4f single molecule magnets. We cover various applied techniques which allow for the correlation of results obtained in the frequency and time domain in order to highlight the specific properties of these compounds and the future challenges towards multidimensional spectroscopic tools. An important point is to understand the details of the interplay of magnetic and optical properties through performing time-resolved studies in the presence of external fields especially magnetic ones. This will enable further exploration of this fundamental interactions i. e. the two components of electromagnetic radiation influencing optical properties.
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Affiliation(s)
- Jonas Braun
- Institute of Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
- Institute for Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
| | - Annie K Powell
- Institute of Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
- Institute for Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
| | - Andreas-Neil Unterreiner
- Institute of Physical Chemistry (IPC), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
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7
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Barrios LA, Capó N, Boulehjour H, Reta D, Tejedor I, Roubeau O, Aromí G. Modulated spin dynamics of [Co 2] coordination helicates via differential strand composition. Dalton Trans 2024; 53:7611-7618. [PMID: 38618945 DOI: 10.1039/d4dt00629a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Coordination supramolecular chemistry provides a versatile entry into materials with functionalities of technological relevance at the nanoscale. Here, we describe how two different bis-pyrazolylpyridine ligands (L1 and L2) assemble with Co(II) ions into dinuclear triple-stranded helicates, in turn, encapsulating different anionic guests. These constructs are described as (Cl@[Co2(L1)3])3+, (SiF6@[Co2(L1)(L2)3])2+ and (ClO4@[Co2(L2)3])3+, as established by single-crystal X-ray diffraction. Extensive magnetic and calorimetric measurements, numerical treatments and theoretical calculations reveal that the individual Co(II) centers of these supramolecular entities exhibit field-induced slow relaxation of magnetization, dominated by direct and Raman mechanisms. While the small variations in the spin dynamics are not easily correlated with the evident structural differences among the three species, the specific heat measurements suggest two vibronic pathways of magnetic relaxation: one that would be associated with the host lattice and another linked with the guest.
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Affiliation(s)
- Leoní A Barrios
- Departament de Química Inorgànica i Orgànica and IN2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
| | - Nuria Capó
- Departament de Química Inorgànica i Orgànica and IN2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
| | - Hanae Boulehjour
- Donostia International Physics Center (DIPC), Donostia, 20018, Spain
| | - Daniel Reta
- Faculty of Chemistry, The University of the Basque Country UPV/EHU, Donostia, 20018, Spain
- Donostia International Physics Center (DIPC), Donostia, 20018, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, 48013, Spain
| | - Inés Tejedor
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC and Universidad de Zaragoza, Plaza San Francisco s/n, 50009, Zaragoza, Spain
| | - Olivier Roubeau
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC and Universidad de Zaragoza, Plaza San Francisco s/n, 50009, Zaragoza, Spain
| | - Guillem Aromí
- Departament de Química Inorgànica i Orgànica and IN2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
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8
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Nain S, Mukhopadhyaya A, Ali ME. Unravelling the Highest Magnetic Anisotropy Among all the nd-Shells in [WCp2]0 Metallocene. Inorg Chem 2024; 63:7401-7411. [PMID: 38578709 DOI: 10.1021/acs.inorgchem.4c00437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024]
Abstract
Single-molecule magnets (SMMs) with a large magnetization reversal barrier are predominated by the lanthanide systems due to their strong spin-orbit coupling (SOC). However, the transition metals have also emerged as potential contenders and the largest magnetic anisotropy has been identified for a cobalt system among any d-series-based SMMs (Bunting et al. Science 2018, 362, eaat7319). In this work, we have explored the magnetic anisotropy in highly axial ligand field systems of metallocene, having different d-subshell (3d4, 4d4, and 5d4). The wave function-based multireference methods including static and dynamic electron correlations have been employed to investigate the zero-field splitting (ZFS) parameters. Here, we report exceptionally large magnetic anisotropy for a 5d complex of [WCp2]0 with the highest energy barrier that is nearly twice as high as the previous record value for the Co complex. We have also observed that the axial ZFS parameter (D) is increasing down the group in the order of 3d < 4d < 5d, pertaining to a large SOC.
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Affiliation(s)
- Sakshi Nain
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
| | - Aritra Mukhopadhyaya
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
| | - Md Ehesan Ali
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
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9
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Lococciolo G, Gupta SK, Dechert S, Demeshko S, Duboc C, Atanasov M, Neese F, Meyer F. Oxygen-Donor Metalloligands Induce Slow Magnetization Relaxation in Zero Field for a Cobalt(II) Complex with {CoO 4} Motif. Inorg Chem 2024; 63:5652-5663. [PMID: 38470330 DOI: 10.1021/acs.inorgchem.4c00054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Most 3d metal-based single-molecule magnets (SMMs) use N-ligands or ligands with even softer donors to impart a particular coordination geometry and increase the zero-field splitting parameter |D|, while complexes with hard O-donor ligands showing slow magnetization relaxation are rare. Here, we report that a diamagnetic NiII complex of a tetradentate ligand featuring two N-heterocyclic carbene and two alkoxide-O donors, [LO,ONi], can serve as a {O,O'}-chelating metalloligand to give a trinuclear complex [(LO,ONi)Co(LO,ONi)](OTf)2 (2) with an elongated tetrahedral {CoIIO4} core, D = -74.3 cm-1, and a spin reversal barrier Ueff = 86.9 cm-1 in the absence of an external dc field. The influence of diamagnetic NiII on the electronic structure of the {CoO4} unit in comparison to [Co(OPh)4]2- (A) has been probed with multireference ab initio calculations. These reveal a contrapolarizing effect of the NiII, which forms stronger metal-alkoxide bonds than the central CoII, inducing a change in ligand field splitting and a 5-fold increase in the magnetic anisotropy in 2 compared to A, with an easy magnetization axis along the Ni-Co-Ni vector. This demonstrates a strategy to enhance the SMM properties of 3d metal complexes with hard O-donors by modulating the ligand field character via the coordination of diamagnetic ions and the benefit of robust metalloligands in that regard.
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Affiliation(s)
- Giuseppe Lococciolo
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, Göttingen 37077, Germany
| | - Sandeep K Gupta
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, Göttingen 37077, Germany
| | - Sebastian Dechert
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, Göttingen 37077, Germany
| | - Serhiy Demeshko
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, Göttingen 37077, Germany
| | - Carole Duboc
- Université Grenoble Alpes, CNRS UMR 5250, DCM, Grenoble F-38000, France
| | - Mihail Atanasov
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Akad. Georgi Bontchev Street 11, Sofia 1113, Bulgaria
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Franc Meyer
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, Göttingen 37077, Germany
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10
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Rabelo R, Toma L, Julve M, Lloret F, Pasán J, Cangussu D, Ruiz-García R, Cano J. How the spin state tunes the slow magnetic relaxation field dependence in spin crossover cobalt(II) complexes. Dalton Trans 2024; 53:5507-5520. [PMID: 38416047 DOI: 10.1039/d4dt00059e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
A novel family of cobalt(II) compounds with tridentate pyridine-2,6-diiminephenyl type ligands featuring electron-withdrawing substituents of general formula [Co(n-XPhPDI)2](ClO4)2·S [n-XPhPDI = 2,6-bis(N-n-halophenylformimidoyl)pyridine with n = 4 (1-3) and 3 (4); X = I (1), Br (2 and 4) and Cl (3); S = MeCN (1 and 2) and EtOAc (3)] has been synthesised and characterised by single-crystal X-ray diffraction, electron paramagnetic resonance, and static (dc) and dynamic (ac) magnetic measurements combined with theoretical calculations. The structures of 1-4 consist of mononuclear bis(chelating) cobalt(II) complex cations, [CoII(n-XPhPDI)2]2+, perchlorate anions, and acetonitrile (1 and 2) or ethyl acetate (3) molecules of crystallisation. This unique series of mononuclear six-coordinate octahedral cobalt(II) complexes displays both thermally-induced low-spin (LS)/high-spin (HS) transition and field-induced slow magnetic relaxation in both LS and HS states. A complete LS ↔ HS transition occurs for 1 and 2, while it is incomplete for 4, one-third of the complexes being HS at low temperatures. In contrast, 3 remains HS in all the temperature range. 1 and 2 show dual spin relaxation dynamics under the presence of an applied dc magnetic field (Hdc), with the occurrence of faster- (FR) and slower-relaxing (SR) processes at lower (Hdc = 1.0 kOe) and higher fields (Hdc = 2.5 kOe), respectively. On the contrary, 3 and 4 exhibit only SR and FR relaxations, regardless of Hdc. Overall, the distinct field-dependence of the single-molecule magnet (SMM) behaviour along with this family of spin-crossover (SCO) cobalt(II)-n-XPhPDI complexes is dominated by Raman mechanisms and, occasionally, with additional temperature-independent Intra-Kramer [LS or HS (D > 0)] or Quantum Tunneling of Magnetisation mechanisms [HS (D < 0)] also contributing.
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Affiliation(s)
- Renato Rabelo
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
- Instituto de Química, Universidade Federal de Goiás, Av. Esperança Campus Samambaia, Goiânia, GO, Brazil
| | - Luminita Toma
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
| | - Miguel Julve
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
| | - Francesc Lloret
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
| | - Jorge Pasán
- Laboratorio de Materiales para Análisis Químico (MAT4LL), Departamento de Química, Facultad de Ciencias, Universidad de La Laguna, 38200 Tenerife, Spain
| | - Danielle Cangussu
- Instituto de Química, Universidade Federal de Goiás, Av. Esperança Campus Samambaia, Goiânia, GO, Brazil
| | - Rafael Ruiz-García
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
| | - Joan Cano
- Instituto de Ciencia Molecular (ICMol), Universitat de València, 46980 Paterna, València, Spain.
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11
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Nagelski AL, Ozerov M, Fataftah MS, Krzystek J, Greer SM, Holland PL, Telser J. Electronic Structure of Three-Coordinate Fe II and Co II β-Diketiminate Complexes. Inorg Chem 2024; 63:4511-4526. [PMID: 38408452 DOI: 10.1021/acs.inorgchem.3c03388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
The β-diketiminate supporting group, [ArNCRCHCRNAr]-, stabilizes low coordination number complexes. Four such complexes, where R = tert-butyl, Ar = 2,6-diisopropylphenyl, are studied: (nacnactBu)ML, where M = FeII, CoII and L = Cl, CH3. These are denoted FeCl, FeCH3, CoCl, and CoCH3 and have been previously reported and structurally characterized. The two FeII complexes (S = 2) have also been previously characterized by Mössbauer spectroscopy, but only indirect assessment of the ligand-field splitting and zero-field splitting (zfs) parameters was available. Here, EPR spectroscopy is used, both conventional field-domain for the CoII complexes (with S = 3/2) and frequency-domain, far-infrared magnetic resonance spectroscopy (FIRMS) for all four complexes. The CoII complexes were also studied by magnetometry. These studies allow accurate determination of the zfs parameters. The two FeII complexes are similar with nearly axial zfs and large magnitude zfs given by D = -37 ± 1 cm-1 for both. The two CoII complexes likewise exhibit large and nearly axial zfs, but surprisingly, CoCl has positive D = +55 cm-1 while CoCH3 has negative D = -49 cm-1. Theoretical methods were used to probe the electronic structures of the four complexes, which explain the experimental spectra and the zfs parameters.
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Affiliation(s)
- Alexandra L Nagelski
- Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Majed S Fataftah
- Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Samuel M Greer
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Patrick L Holland
- Department of Chemistry, Yale University, New Haven, Connecticut 06511, United States
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605, United States
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12
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Hand AT, Watson-Sanders BD, Xue ZL. Spectroscopic techniques to probe magnetic anisotropy and spin-phonon coupling in metal complexes. Dalton Trans 2024; 53:4390-4405. [PMID: 38380640 DOI: 10.1039/d3dt03609j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Magnetism of molecular quantum materials such as single-molecule magnets (SMMs) has been actively studied for potential applications in the new generation of high-density data storage using SMMs and quantum information science. Magnetic anisotropy and spin-phonon coupling are two key properties of d- and f-metal complexes. Here, phonons refer to both intermolecular and intramolecular vibrations. Direct determination of magnetic anisotropy and experimental studies of spin-phonon coupling are critical to the understanding of molecular magnetism. This article discusses our recent approach in using three complementary techniques, far-IR and Raman magneto-spectroscopies (FIRMS and RaMS, respectively) and inelastic neutron scatterings (INS), to determine magnetic excited states. Spin-phonon couplings are observed in FIRMS and RaMS. DFT phonon calculations give energies and symmetries of phonons as well as calculated INS spectra which help identify magnetic peaks in experimental INS spectra.
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Affiliation(s)
- Adam T Hand
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA.
| | | | - Zi-Ling Xue
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA.
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13
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Huzan MS, Burrow TG, Fix M, Breitner FA, Chong SK, Bencok P, Aramini M, Jesche A, Baker ML. Quantifying the influence of 3d-4s mixing on linearly coordinated metal-ions by L 2,3-edge XAS and XMCD. Chem Sci 2024; 15:2433-2442. [PMID: 38362431 PMCID: PMC10866348 DOI: 10.1039/d3sc06308a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 12/22/2023] [Indexed: 02/17/2024] Open
Abstract
The mixing valence d and s orbitals are predicted to strongly influence the electronic structure of linearly coordinated molecules, including transition metals, lanthanides and actinides. In specific cases, novel magnetic properties, such as single-ion magnetic coercivity or long spin decoherence times, ensue. Inspired by how the local coordination symmetry can engender such novel phenomena, in this study, we focus our attention on dopants (Mn, Fe, Co, Ni, Cu) in lithium nitride to accept innovation from molecular magnetism in a high symmetry P6/mmm solid-state crystal. The linear coordination environment results in strong 3d-4s mixing, proving to be an ideal series to investigate the role of d-s mixing and bonding on electronic structure and magnetism. It is shown that L2,3-edge XAS can be applied to experimentally identify the presence of 3d-4s mixing and the influence this has on the ligand-field splitting. XMCD specifies how spin-orbit coupling is affected. The combined spectroscopies are analysed to determine the effect of 4s mixing with support from ab initio calculations. The results provide new insight of relevance to future applications, including quantum information processing and the sustainable replacement of rare earths in magnets.
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Affiliation(s)
- Myron S Huzan
- Department of Chemistry, The University of Manchester Manchester M13 9PL UK
- The University of Manchester at Harwell, Diamond Light Source, Harwell Campus OX11 0DE UK
| | - Timothy G Burrow
- Department of Chemistry, The University of Manchester Manchester M13 9PL UK
- The University of Manchester at Harwell, Diamond Light Source, Harwell Campus OX11 0DE UK
| | - Manuel Fix
- EP VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg D-86159 Augsburg Germany
| | - Franziska A Breitner
- EP VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg D-86159 Augsburg Germany
| | - Sut Kei Chong
- Department of Chemistry, The University of Manchester Manchester M13 9PL UK
- The University of Manchester at Harwell, Diamond Light Source, Harwell Campus OX11 0DE UK
| | - Peter Bencok
- Diamond Light Source, Harwell Science and Innovation Campus Chilton, Didcot OX11 0DE UK
| | - Matteo Aramini
- Diamond Light Source, Harwell Science and Innovation Campus Chilton, Didcot OX11 0DE UK
| | - Anton Jesche
- EP VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg D-86159 Augsburg Germany
| | - Michael L Baker
- Department of Chemistry, The University of Manchester Manchester M13 9PL UK
- The University of Manchester at Harwell, Diamond Light Source, Harwell Campus OX11 0DE UK
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14
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Villa-Pérez C, Zabala-Lekuona A, Vitorica-Yrezabal IJ, Seco JM, Cepeda J, Echeverría GA, Soria DB. Spin canting and slow magnetic relaxation in mononuclear cobalt(II) sulfadiazine ternary complexes. Dalton Trans 2024. [PMID: 38252541 DOI: 10.1039/d3dt02359a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Monomeric [Co(SDZ)2phen] (1) and [Co(SDZ)(bq)Cl] (2) complexes (SDZ = sulfadiazine, phen = 1,10-phenanthroline, and bq = 2,2'-biquinoline) have been synthesized and characterized. X-ray diffraction studies indicate that SDZ acts as a bidentate ligand coordinating through the sulfonamide and the pyrimidine N atoms in both compounds. In complex 1, the coordination sphere consists of two SDZ ligands and a bis-chelating phen ligand, giving rise to a CoN6 coordination sphere. On the other hand, 2 has a CoN4Cl core, with two N-atoms from SDZ and two from the bq ligand. Both compounds have been studied by dc and ac magnetometry and shown to display slow magnetic relaxation under an optimum external dc field (1 kOe) at low temperatures. Moreover, compound 2 displays long range magnetic ordering provided by spin-canted antiferromagnetism, which has been characterized by further field-dependent magnetic susceptibility measurements, FC/ZFC curves, hysteresis loops and frequency-independent ac curves. The signs of the calculated D parameters, positive in 1 and negative in 2, have been rationalized according to the two lowest-lying transitions in the orbital energy diagrams derived from ab initio ligand field theory (AILFT). In a subsequent attempt to reveal the possible hidden zero-field SMM behaviour, Ni(II)-based 3 and Co(II)-doped Ni(II)-based (with a Ni : Co ratio of 0.9 : 0.1) heterometallic compound 2Ni were synthesized.
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Affiliation(s)
- Cristian Villa-Pérez
- CEQUINOR (CONICET, CCT - La Plata), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, Bv. 120 no. 1465, 1900, La Plata, Argentina.
| | - Andoni Zabala-Lekuona
- Departamento de Química Aplicada, Facultad de Química, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Paseo Manuel Lardizabal no. 3, 20018, Donostia, Spain.
| | - Iñigo J Vitorica-Yrezabal
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071, Granada, Spain
| | - José Manuel Seco
- Departamento de Química Aplicada, Facultad de Química, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Paseo Manuel Lardizabal no. 3, 20018, Donostia, Spain.
| | - Javier Cepeda
- Departamento de Química Aplicada, Facultad de Química, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Paseo Manuel Lardizabal no. 3, 20018, Donostia, Spain.
| | - Gustavo Alberto Echeverría
- IFLP (CONICET, CCT - La Plata), Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, 47 y 115, 1900, La Plata, Argentina
| | - Delia Beatriz Soria
- CEQUINOR (CONICET, CCT - La Plata), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, Bv. 120 no. 1465, 1900, La Plata, Argentina.
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15
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Vieru V, Gómez-Coca S, Ruiz E, Chibotaru LF. Increasing the Magnetic Blocking Temperature of Single-Molecule Magnets. Angew Chem Int Ed Engl 2024; 63:e202303146. [PMID: 37539652 DOI: 10.1002/anie.202303146] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 07/18/2023] [Accepted: 08/02/2023] [Indexed: 08/05/2023]
Abstract
The synthesis of single-molecule magnets (SMMs), magnetic complexes capable of retaining magnetization blocking for a long time at elevated temperatures, has been a major concern for magnetochemists over the last three decades. In this review, we describe basic SMMs and the different approaches that allow high magnetization-blocking temperatures to be reached. We focus on the basic factors affecting magnetization blocking, magnetic axiality and the height of the blocking barrier, which can be used to group different families of complexes in terms of their SMM efficiency. Finally, we discuss several practical routes for the design of mono- and polynuclear complexes that could be applied in memory devices.
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Affiliation(s)
- Veacheslav Vieru
- Maastricht Science Programme, Faculty of Science and Engineering, Maastricht University, 6229 EN, Maastricht, The Netherlands
| | - Silvia Gómez-Coca
- Departament de Química Inorgànica i Orgànica, Universitat de Barcelona, 08028, Barcelona, Spain
- Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Eliseo Ruiz
- Departament de Química Inorgànica i Orgànica, Universitat de Barcelona, 08028, Barcelona, Spain
- Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Liviu F Chibotaru
- Theory of Nanomaterials Group, Katholieke Universiteit Leuven, 3001, Leuven, Belgium
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16
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Vasiliev AV, Sharifullin TZ, Demidova ED, Kremer RK, Kazin PE. A Dy-based single ion magnet in a SrLaGaO 4 matrix: enhanced parameters in an expanded crystal lattice. Dalton Trans 2023; 52:17747-17751. [PMID: 37970917 DOI: 10.1039/d3dt03387b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Dy3+ doped SrLaGaO4 exhibits unusually slow relaxation of magnetization determined by two widely separated excited Kramers doublets with a second remagnetization energy barrier of 223 cm-1. This value considerably exceeds that for analogous Ca(Y,Dy)AlO4 in spite of the apparently enlarged Dy3+ coordination sphere.
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Affiliation(s)
- Alexander V Vasiliev
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
| | - Timur Z Sharifullin
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
| | - Elena D Demidova
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
| | - Reinhard K Kremer
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Pavel E Kazin
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
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17
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Zahradníková E, Sutter JP, Halaš P, Drahoš B. Trigonal prismatic coordination geometry imparted by a macrocyclic ligand: an approach to large axial magnetic anisotropy for Co(II). Dalton Trans 2023. [PMID: 38015562 DOI: 10.1039/d3dt02639f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Large uniaxial magnetic anisotropy, expressed by a negative value of the axial zero-field splitting parameter D, has been achieved in a series of trigonal prismatic Co(II) complexes with the general formula [Co(L)X]Y, where L = 1,5,13,17,22-pentaazatricyclo[15.2.2.17,11]docosa-7,9,11(22)-triene, X = Cl-(1a,b), Br-(2), N3-(3), NCO-(4), NCS-(5), NCSe-(6), and Y = Cl-(1), Br-(2), NCS-(4), NCSe-(5), ClO4-(3,6). Complexes 1-6 are six-coordinate with the distorted trigonal prismatic geometry imparted by the pentadentate pyridine-/piperazine-based macrocyclic ligand L and by one monovalent coligand X-. Based on magnetic studies, all complexes 1-6 exhibit strong magnetic anisotropy with negative D-values ranging from about -20 to -41 cm-1. This variation in D (i.e. the increase of magnetic anisotropy) parallels the trend obtained by theoretical calculations and the lesser distortion of the coordination sphere with respect to the trigonal prismatic reference geometry. AC magnetic susceptibility investigations revealed field-induced single-molecule magnet behaviour for all complexes except Cl- derivative 1. The series investigated represents a rare example of Co(II) complexes with a robust trigonal prismatic geometry.
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Affiliation(s)
- Eva Zahradníková
- Department of Inorganic Chemistry, Faculty of Science, Palacký University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic.
| | - Jean-Pascal Sutter
- Laboratoire de Chimie de Coordination du CNRS (LCC-CNRS), Université de Toulouse, CNRS, Toulouse, France.
| | - Petr Halaš
- Department of Inorganic Chemistry, Faculty of Science, Palacký University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic.
| | - Bohuslav Drahoš
- Department of Inorganic Chemistry, Faculty of Science, Palacký University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic.
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18
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Yang Y, Hong L, Bellaiche L, Xiang H. Toward Ultimate Memory with Single-Molecule Multiferroics. J Am Chem Soc 2023; 145:25357-25364. [PMID: 37948323 DOI: 10.1021/jacs.3c09294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
The demand for high-density storage is urgent in the current era of data explosion. Recently, several single-molecule (-atom) magnets and ferroelectrics have been reported to be promising candidates for high-density storage. As another promising candidate, single-molecule multiferroics are not only small in size but also possess ferroelectric and magnetic orderings, which can sometimes be strongly coupled and used as data storage to realize the combination of electric writing and magnetic reading. However, they have been rarely proposed and have never been experimentally reported. Here, by building Hamiltonian models, we propose a new model of single-molecule multiferroics in which electric dipoles and magnetic moments are parallel and can rotate with the rotation of the single molecule. Furthermore, by performing spin-lattice dynamics simulations, we reveal the conditions (e.g., large enough single-ion anisotropy and an appropriate electric field) under which the new single-molecule multiferroic can arise. Based on this model, as well as first-principles calculations, a realistic example of Co(NH3)4N@SWCNT is constructed and numerically confirmed to demonstrate the feasibility of the new single-molecule multiferroic model. Our work not only sheds light on the discovery of single-molecule multiferroics but also provides a new guideline to design multifunctional materials for ultimate memory devices.
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Affiliation(s)
- Yali Yang
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
- Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Qi Zhi Institute, Shanghai 200030, China
| | - Liangliang Hong
- Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Qi Zhi Institute, Shanghai 200030, China
| | - Laurent Bellaiche
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Hongjun Xiang
- Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Qi Zhi Institute, Shanghai 200030, China
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19
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Zabala-Lekuona A, Landart-Gereka A, Quesada-Moreno MM, Mota AJ, Díaz-Ortega IF, Nojiri H, Krzystek J, Seco JM, Colacio E. Zero-Field SMM Behavior Triggered by Magnetic Exchange Interactions and a Collinear Arrangement of Local Anisotropy Axes in a Linear Co 3II Complex. Inorg Chem 2023. [PMID: 37991724 DOI: 10.1021/acs.inorgchem.3c02817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
A new linear trinuclear Co(II)3 complex with a formula of [{Co(μ-L)}2Co] has been prepared by self-assembly of Co(II) ions and the N3O3-tripodal Schiff base ligand H3L, which is obtained from the condensation of 1,1,1-tris(aminomethyl)ethane and salicylaldehyde. Single X-ray diffraction shows that this compound is centrosymmetric with triple-phenolate bridging groups connecting neighboring Co(II) ions, leading to a paddle-wheel-like structure with a pseudo-C3 axis lying in the Co-Co-Co direction. The Co(II) ions at both ends of the Co(II)3 molecule exhibit distorted trigonal prismatic CoN3O3 geometry, whereas the Co(II) at the middle presents an elongated trigonal antiprismatic CoO6 geometry. The combined analysis of the magnetic data and theoretical calculations reveal strong easy-axis magnetic anisotropy for both types of Co(II) ions (|D| values higher than 115 cm-1) with the local anisotropic axes lying on the pseudo-C3 axis of the molecule. The magnetic exchange interaction between the middle and ends Co(II) ions, extracted by using either a Hamiltonian accounting for the isotropic magnetic coupling and ZFS or the Lines' model, was found to be medium to strong and antiferromagnetic in nature, whereas the interaction between the external Co(II) ions is weak antiferromagnetic. Interestingly, the compound exhibits slow relaxation of magnetization and open hysteresis at zero field and therefore SMM behavior. The significant magnetic exchange coupling found for [{Co(μ-L)}2Co] is mainly responsible for the quenching of QTM, which combined with the easy-axis local anisotropy of the CoII ions and the collinearity of their local anisotropy axes with the pseudo-C3 axis favors the observation of SMM behavior at zero field.
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Affiliation(s)
- Andoni Zabala-Lekuona
- Departamento de Química Aplicada, Facultad de Química, Universidad del País Vasco (UPV/EHU), 20018 Donostia-San Sebastián, Spain
| | - Aritz Landart-Gereka
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - María Mar Quesada-Moreno
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Antonio J Mota
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Ismael F Díaz-Ortega
- Institute for Materials Research, Tohoku University, Katahira, Sendai 980-8577, Japan
| | - Hiroyuki Nojiri
- Institute for Materials Research, Tohoku University, Katahira, Sendai 980-8577, Japan
| | - Jurek Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - José M Seco
- Departamento de Química Aplicada, Facultad de Química, Universidad del País Vasco (UPV/EHU), 20018 Donostia-San Sebastián, Spain
| | - Enrique Colacio
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
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20
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Bhatt G, Sharma T, Gupta SK, Meyer F, Rajaraman G, Murugavel R. Tuning Magnetic Anisotropy in Co(II) Tetrahedral Carbazole-Modified Phosphine Oxide Single-Ion Magnets: Importance of Structural Distortion versus Heavy-Ion Effect. Inorg Chem 2023; 62:18915-18925. [PMID: 37947449 DOI: 10.1021/acs.inorgchem.3c02401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Three mononuclear cobalt(II) tetrahedral complexes [Co(CzPh2PO)2X2] (CzPh2PO = (9H-carbazol-9-yl)diphenylphosphine oxide and X = Cl (1), Br (2), I (3)) have been synthesized using a simple synthetic approach to examine their single-ion magnetic (SIM) behavior. A detailed study of the variation in the dynamic magnetic properties of the Co(II) ion in a tetrahedral ligand field has been carried out by the change of the halide ligand. The axial zero-field splitting parameter D was found to vary from -16.4 cm-1 in 1 to -13.8 cm-1 in 2 and +14.6 cm-1 in 3. All the new complexes exhibit field-induced SIM behavior. The results obtained from ab initio CASSF calculations match well with the experimental data, revealing how halide ions induce a change in the D value as we move from Cl- to I-. The ab initio calculations further reveal that the change in the sign of D is due to the multideterminant characteristics of the ground state wave function of 1 and 2, while single-determinant characteristics are instead observed for 3. To gain a better understanding of the relationship between the structural distortion and the sign and magnitude of D values, magnetostructural D correlations were developed using angular relationships, revealing the importance of structural distortions over the heavy halide effect in controlling the sign of D values. This study broadens the scope of employing electronically and sterically modified phosphine oxide ligands in building new types of air-stable Co(II) SIMs.
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Affiliation(s)
- Gargi Bhatt
- Department of Chemistry, Indian Institute of Technology Bombay, Powai 400076, Mumbai, India
| | - Tanu Sharma
- Department of Chemistry, Indian Institute of Technology Bombay, Powai 400076, Mumbai, India
| | - Sandeep K Gupta
- University of Göttingen, Institute of Inorganic Chemistry, Göttingen D-37077, Germany
| | - Franc Meyer
- University of Göttingen, Institute of Inorganic Chemistry, Göttingen D-37077, Germany
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai 400076, Mumbai, India
| | - Ramaswamy Murugavel
- Department of Chemistry, Indian Institute of Technology Bombay, Powai 400076, Mumbai, India
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21
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Wu DQ, Kumari K, Wan Y, Gao X, Guo M, Liu G, Shao D, Zhai B, Singh SK. Binuclear cobalt(II) and two-dimensional manganese(II) coordination compounds self-assembled by mixed bipyridine-tetracarboxylic ligands with single-ion magnet properties. Dalton Trans 2023; 52:16197-16205. [PMID: 37873572 DOI: 10.1039/d3dt03016d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
A cobalt(II) complex and manganese(II) coordination polymer, formulated as [Co2(H2btca)(mbpy)4][H2btca]·4H2O (1) and {Mn2(btca)(mbpy)2(H2O)2}n (2) (H4btca = 1,2,4,5-benzenetetracarboxylic acid; mbpy = 4,4'-dimethyl-2,2'-bipyridyl), constructed by mixed bipyridine-tetracarboxylic ligands were synthesized and characterized. Single-crystal structural analyses reveal that compound 1 is a discrete neutral binuclear molecule, while compound 2 is a two-dimensional (2D) coordination polymer. The metal ions in these compounds are well isolated, with an intramolecular Co2+⋯Co2+ distance of 9.170 Å for 1 and Mn2+⋯Mn2+ separation of 10.984 and 11.164 Å for 2 due to the bulk tetracarboxylic linker. This isolation gives rise to a single-ion magnetism origin of the compounds. Magnetic studies reveal a large zero-field splitting parameter D of 82.6 cm-1 for 1, while a very small D of 0.42 cm-1 was observed for 2. Interestingly, dynamic ac magnetic measurements exhibited slow magnetic relaxation under the external dc field of the two compounds, revealing the field-supported single-ion magnet (SIM) of 1 and 2. The detailed theoretical calculations were further applied to understand the electronic structures, magnetic anisotropy, and relaxation dynamics in 1 and 2. Combined with our recently reported compound (Eur. J. Inorg. Chem., 2022, e202200354), the foregoing results provide not only a rare binuclear cobalt(II) SIM and the first 2D manganese(II) SIM coordination polymer but also a bipyridine-tetracarboxylic ligand approach toward novel SIMs.
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Affiliation(s)
- Dong-Qing Wu
- Engineering Research Center of Photoelectric Functional Material, School of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, P. R. China.
| | - Kusum Kumari
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi-502285, Sangareddy, Telangana, India.
| | - Yi Wan
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China.
| | - Xueling Gao
- Engineering Research Center of Photoelectric Functional Material, School of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, P. R. China.
| | - Mengxi Guo
- Engineering Research Center of Photoelectric Functional Material, School of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, P. R. China.
| | - Genyan Liu
- Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, Wuhan Institute of Technology, Wuhan 430205, P. R. China
| | - Dong Shao
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China.
| | - Bin Zhai
- Engineering Research Center of Photoelectric Functional Material, School of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, P. R. China.
| | - Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi-502285, Sangareddy, Telangana, India.
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22
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Giraldo JN, Hrubý J, Vavrečková Š, Fellner OF, Havlíček L, Henry D, de Silva S, Herchel R, Bartoš M, Šalitroš I, Santana VT, Barbara P, Nemec I, Neugebauer P. Tetracoordinate Co(II) complexes with semi-coordination as stable single-ion magnets for deposition on graphene. Phys Chem Chem Phys 2023; 25:29516-29530. [PMID: 37901907 PMCID: PMC10631493 DOI: 10.1039/d3cp01426f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 10/03/2023] [Indexed: 10/31/2023]
Abstract
We present a theoretical and experimental study of two tetracoordinate Co(II)-based complexes with semi-coordination interactions, i.e., non-covalent interactions involving the central atom. We argue that such interactions enhance the thermal and structural stability of the compounds, making them appropriate for deposition on substrates, as demonstrated by their successful deposition on graphene. DC magnetometry and high-frequency electron spin resonance (HF-ESR) experiments revealed an axial magnetic anisotropy and weak intermolecular antiferromagnetic coupling in both compounds, supported by theoretical predictions from complete active space self-consistent field calculations complemented by N-electron valence state second-order perturbation theory (CASSCF-NEVPT2), and broken-symmetry density functional theory (BS-DFT). AC magnetometry demonstrated that the compounds are field-induced single-ion magnets (SIMs) at applied static magnetic fields, with slow relaxation of magnetization governed by a combination of quantum tunneling, Orbach, and direct relaxation mechanisms. The structural stability under ambient conditions and after deposition was confirmed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Theoretical modeling by DFT of different configurations of these systems on graphene revealed n-type doping of graphene originating from electron transfer from the deposited molecules, confirmed by electrical transport measurements and Raman spectroscopy.
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Affiliation(s)
- Jorge Navarro Giraldo
- Central European Institute of Technology, CEITEC BUT, Purkyňova 656/123, 61200 Brno, Czech Republic.
| | - Jakub Hrubý
- Central European Institute of Technology, CEITEC BUT, Purkyňova 656/123, 61200 Brno, Czech Republic.
| | - Šárka Vavrečková
- Central European Institute of Technology, CEITEC BUT, Purkyňova 656/123, 61200 Brno, Czech Republic.
- Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technická 2, 61669 Brno, Czech Republic
| | - Ondřej F Fellner
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, 77147 Olomouc, Czech Republic
| | - Lubomír Havlíček
- Central European Institute of Technology, CEITEC BUT, Purkyňova 656/123, 61200 Brno, Czech Republic.
- Institute of Physics of Materials, Czech Academy of Sciences, Žižkova 22, 61662 Brno, Czech Republic
| | - DaVonne Henry
- Department of Physics, Georgetown University, Washington, DC, USA
| | - Shehan de Silva
- Department of Physics, Georgetown University, Washington, DC, USA
| | - Radovan Herchel
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, 77147 Olomouc, Czech Republic
| | - Miroslav Bartoš
- Central European Institute of Technology, CEITEC BUT, Purkyňova 656/123, 61200 Brno, Czech Republic.
| | - Ivan Šalitroš
- Central European Institute of Technology, CEITEC BUT, Purkyňova 656/123, 61200 Brno, Czech Republic.
- Department of Inorganic Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Bratislava SK-81237, Slovakia
| | - Vinicius T Santana
- Central European Institute of Technology, CEITEC BUT, Purkyňova 656/123, 61200 Brno, Czech Republic.
| | - Paola Barbara
- Department of Physics, Georgetown University, Washington, DC, USA
| | - Ivan Nemec
- Central European Institute of Technology, CEITEC BUT, Purkyňova 656/123, 61200 Brno, Czech Republic.
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, 77147 Olomouc, Czech Republic
| | - Petr Neugebauer
- Central European Institute of Technology, CEITEC BUT, Purkyňova 656/123, 61200 Brno, Czech Republic.
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23
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Tarannum I, Moorthy S, Singh SK. Understanding electrostatics and covalency effects in highly anisotropic organometallic sandwich dysprosium complexes [Dy(C mR m) 2] (where R = H, SiH 3, CH 3 and m = 4 to 9): a computational perspective. Dalton Trans 2023; 52:15576-15589. [PMID: 37786345 DOI: 10.1039/d3dt01646c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
In this article, we have thoroughly studied the electronic structure and 4f-ligand covalency of six mononuclear dysprosium organometallic sandwich complexes [Dy(CmRm)2]n+/- (where R = H, SiH3, CH3; m = 4 to 9; n = 1, 3) using both the scalar relativistic density functional and complete active space self-consistent field (CASSCF) and N-electron valence perturbation theory (NEVPT2) method to shed light on the ligand field effects in fine-tuning the magnetic anisotropy of these complexes. Energy decomposition analysis (EDA) and ab initio-based ligand field theory AILFT calculations predict the sizable 4f-ligand covalency in all these complexes. The analysis of CASSCF/NEVPT2 computed spin-Hamiltonian (SH) parameters indicates the stabilization of mJ |±15/2〉 for [Dy(C4(SiH3)4)2]- (1), [Dy(C5(CH3)5)2]+ (2) and [Dy(C6H6)2]3+ (3) complexes with the Ucal value of 1867.5, 1621.5 and 1070.8 cm-1, respectively. On the other hand, we observed mJ |±9/2〉 as the ground state for [Dy(C7H7)2]3- (4) and [Dy(C8H8)2]- (5) complexes with significantly smaller Ucal values of 237.1 and 38.6 cm-1 respectively. For the nine-membered ring [Dy(C9H9)2]+ (6) complex, we observed the stabilization of the mJ |±1/2〉 ground state, with the first excited state being located ∼29 cm-1 higher in energy. AILFT-NEVPT2 ligand field splitting analysis indicates that the presence of π-type 4f-ligand interactions in complexes 1-3 help generate the axial-ligand field, while the δ-type interactions in complexes 4-5 generate the equatorial ligand field despite the ligands approaching from the axial direction. As the ring size increases, φ-type interactions dominate, generating a pure equatorial ligand field stabilising mJ |±1/2〉 as the ground state for 6. Calculations suggest that the nature of the ligand field mainly governs the Ucal values in the following order: 4f-Lσ > 4f-Lπ > 4f-Lδ > 4f-Lφ. Calculations were performed by replacing ligands with CHELPG charges to access the crystal field (CF) effects which suggests the stabilization of pure mJ |±15/2〉 in all the charge-embedded models (1Q-6Q). Our findings point out that the crystal field and ligand field effects complement each other and generate a giant barrier for magnetic relaxation in the small ring complexes 1-3, while a relatively weak crystal field and adverse 4f-Lδ/4f-Lφ interactions diminish the SMM behaviour in the large ring complexes 4-6.
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Affiliation(s)
- Ibtesham Tarannum
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana, 502285, India.
| | - Shruti Moorthy
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana, 502285, India.
| | - Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana, 502285, India.
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24
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Dey A, Ali J, Moorthy S, Gonzalez JF, Pointillart F, Singh SK, Chandrasekhar V. Field induced single ion magnet behavior in Co II complexes in a distorted square pyramidal geometry. Dalton Trans 2023; 52:14807-14821. [PMID: 37791680 DOI: 10.1039/d3dt01769a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
We report three CoII-based complexes with the general formula [CoII(L)(X)2] by changing the halide/pseudo-halide ions [X = NCSe (1SeCN); Cl (2Cl) and Br (3Br)]. The obtained τ5 and CShM values confirm a distorted square pyramidal geometry around the CoII ion in all these complexes. In these three complexes, the central CoII ion is situated above the basal plane of the square pyramidal geometry. The extent of distortion from the ideal SPY-5 geometry differs upon changing the coordinating halide/pseudo-halide ion in these complexes. This essentially results in the alteration of the anisotropic parameter D and hence impacts the magnetic properties in these complexes. This phenomenon has been corroborated with the aid of theoretical investigations. All these complexes display field-induced SIM behaviour with magnetic relaxation occurring through a combination of processes depending on the applied dc magnetic field values and dilution.
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Affiliation(s)
- Atanu Dey
- Department of Chemistry, Gandhi Institute of Technology and Management (GITAM), NH 207, Nagadenehalli, Doddaballapur Taluk, Bengaluru 561203, India.
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500 046, India.
| | - Junaid Ali
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500 046, India.
| | - Shruti Moorthy
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502285, Telangana, India.
| | - Jessica Flores Gonzalez
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000 Rennes, France.
| | - Fabrice Pointillart
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000 Rennes, France.
| | - Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502285, Telangana, India.
| | - Vadapalli Chandrasekhar
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500 046, India.
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
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25
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Wang LX, Wu XF, Jin XX, Li JY, Wang BW, Liu JY, Xiang J, Gao S. Slow magnetic relaxation in 8-coordinate Mn(II) compounds. Dalton Trans 2023; 52:14797-14806. [PMID: 37812439 DOI: 10.1039/d3dt02307a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The design and synthesis of high-spin Mn(II)-based single-molecule magnets (SMMs) have not been well developed to a great extent, as compared with a large number of SMMs based on the other first row transition metal complexes. In light of our success in designing Fe(II), Co(II) and Fe(III)-based SMMs with a high coordination number of 8, it is of great interest to design Mn(II) analogues with such a strategy. In this contribution, four Mn(II) compounds, [MnII(Ln)2](ClO4)2 (1-4) were obtained from reactions of neutral tetradentate ligands, L1-L4, with hydrated MnII(ClO4)2 (L1 = 2,9-bis(carbomethoxy)-1,10-phenanthroline, L2 = 2,9-bis(carbomethoxy)-2,2'-dipyridine, L3 = N2,N9-dibutyl-1,10-phenanthroline-2,9-dicarboxamide, L4 = 6,6'-bis(2-(tert-butyl)-2H-tetrazol-5-yl)-2,2'-bipyridine). Their crystal structures have been determined by X-ray crystallography and it clearly shows that the Mn(II) centers in these compounds have an oversaturated coordination number of 8. Their magnetic properties have been investigated in detail; to our surprise, all of these Mn(II) compounds show interesting slow magnetic relaxation behaviors under an applied direct current field, although they have very small negative D values.
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Affiliation(s)
- Li-Xin Wang
- Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education), School of Optoelectronic Materials and Technology, Jianghan University, Wuhan, 430056, China.
- College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434020, Hubei, P. R. China
| | - Xiao-Fan Wu
- State Key Laboratory of Rare Earth Materials Chemistry and Applications and PKU-HKU Joint Laboratory on Rare Earth Materials and Bioinorganic Chemistry, Peking University, Beijing 100871, P. R. China.
| | - Xin-Xin Jin
- State Key Laboratory of Rare Earth Materials Chemistry and Applications and PKU-HKU Joint Laboratory on Rare Earth Materials and Bioinorganic Chemistry, Peking University, Beijing 100871, P. R. China.
| | - Jia-Yi Li
- College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434020, Hubei, P. R. China
| | - Bing-Wu Wang
- State Key Laboratory of Rare Earth Materials Chemistry and Applications and PKU-HKU Joint Laboratory on Rare Earth Materials and Bioinorganic Chemistry, Peking University, Beijing 100871, P. R. China.
| | - Ji-Yan Liu
- Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education), School of Optoelectronic Materials and Technology, Jianghan University, Wuhan, 430056, China.
| | - Jing Xiang
- Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education), School of Optoelectronic Materials and Technology, Jianghan University, Wuhan, 430056, China.
- College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434020, Hubei, P. R. China
| | - Song Gao
- State Key Laboratory of Rare Earth Materials Chemistry and Applications and PKU-HKU Joint Laboratory on Rare Earth Materials and Bioinorganic Chemistry, Peking University, Beijing 100871, P. R. China.
- School of Chemistry, Sun Yat-Sen University, Guangzhou, China
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26
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Kotrle K, Atanasov M, Neese F, Herchel R. Theoretical Magnetic Relaxation and Spin-Phonon Coupling Study in a Series of Molecular Engineering Designed Bridged Dysprosocenium Analogues. Inorg Chem 2023; 62:17499-17509. [PMID: 37812145 PMCID: PMC10598879 DOI: 10.1021/acs.inorgchem.3c02916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Indexed: 10/10/2023]
Abstract
A detailed computational study of hypothetical sandwich dysprosium double-decker complexes, bridged by various numbers of aliphatic linkers, was performed to evaluate the effect of the structural modifications on their ground-state magnetic sublevels and assess their potential as candidates for single-molecule magnets (SMMs). The molecular structures of seven complexes were optimized using the TPSSh functional, and the electronic structure and magnetic properties were investigated using the complete active space self-consistent field method (CASSCF). Estimates of the magnetic moment blocking barrier (Ueff) and blocking temperatures (TB) are reported. In addition, a new method based on computed derivatives of effective demagnetization barriers Ueff with respect to vibrational normal modes was introduced and applied to evaluate the impact of spin-phonon coupling on the SMM properties. On the basis of the computed parameters, we have identified promising candidates with properties superior to those of the existing single-molecule magnets.
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Affiliation(s)
- Kamil Kotrle
- Department
of Inorganic Chemistry, Faculty of Science, Palacký University Olomouc, Olomouc CZ-77146, Czech Republic
| | - Mihail Atanasov
- Max-Planck-Institut
für Kohlenforschung, Mülheim an der Ruhr D-45470, Germany
- Institute
of General and Inorganic Chemistry, Bulgarian
Academy of Sciences, Sofia 1113, Bulgaria
| | - Frank Neese
- Max-Planck-Institut
für Kohlenforschung, Mülheim an der Ruhr D-45470, Germany
| | - Radovan Herchel
- Department
of Inorganic Chemistry, Faculty of Science, Palacký University Olomouc, Olomouc CZ-77146, Czech Republic
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27
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Wang M, Han Z, Gou X, Shi W, Zhang YQ, Cheng P. Alkyl Chains Modulated Magnetization Dynamics of Mononuclear Trigonal Prismatic Co II Complexes. Chemistry 2023; 29:e202301693. [PMID: 37498805 DOI: 10.1002/chem.202301693] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 07/29/2023]
Abstract
Four benzeneboron-capped mononuclear CoII complexes with different alkyl substitutions on the fourth position of phenylboronic acid were obtained. The CoII ions are all wrapped by the pocket-like ligands and located in trigonal prismatic coordination geometries. Alternating-current magnetic susceptibility measurements reveal that they show different magnetization dynamics, such as distinct relaxation rates at the same temperature, the faster QTM rates for the ethyl and propyl substituted complexes, as well as different relaxation processes. Magneto-structural correlation study reveals that the various deviations of coordination geometry of CoII ion, diverse crystal packings and possible different vibration modes of substituents caused by modifying alkyl chains are the key factors affecting the magnetization dynamics. This work demonstrates that the alkyl chains even locating far away from the metal center can have a large impact on the magnetic behavior of the CoII complex with a very rigid coordination geometry, offering a new perspective towards transition metal based single-molecule magnets.
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Affiliation(s)
- Mengmeng Wang
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE) and Frontiers Science Center for New Organic MatterCollege of Chemistry, Nankai University, Tianjin, 300071, China
| | - Zongsu Han
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE) and Frontiers Science Center for New Organic MatterCollege of Chemistry, Nankai University, Tianjin, 300071, China
| | - Xiaoshuang Gou
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE) and Frontiers Science Center for New Organic MatterCollege of Chemistry, Nankai University, Tianjin, 300071, China
| | - Wei Shi
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE) and Frontiers Science Center for New Organic MatterCollege of Chemistry, Nankai University, Tianjin, 300071, China
| | - Yi-Quan Zhang
- School of Physical Science and Technology, Nanjing Normal University, Nanjing, 210023, P. R. China
| | - Peng Cheng
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE) and Frontiers Science Center for New Organic MatterCollege of Chemistry, Nankai University, Tianjin, 300071, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin, 300192, China
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28
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Wakizaka M, Ishikawa R, Tanaka H, Gupta S, Takaishi S, Yamashita M. Creation of a Field-Induced Co(II) Single-Ion Magnet by Doping into a Zn(II) Diamagnetic Metal-Organic Framework. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2301966. [PMID: 37178437 DOI: 10.1002/smll.202301966] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 05/01/2023] [Indexed: 05/15/2023]
Abstract
The combination of single-ion magnets (SIMs) and metal-organic frameworks (MOFs) is expected to produce new quantum materials. The principal issue to be solved in this regard is the development of new strategies for the synthesis of SIM-MOFs. This work demonstrates a new simple strategy for the synthesis of SIM-MOFs where a diamagnetic MOF is used as the framework into which the SIM sites are doped. 1, 0.5, and 0.2 mol% of the Co(II) ions are doped into the Zn(II) sites of [CH6 N3 ][ZnII (HCOO)3 ]. The doped Co(II) sites in the MOFs perform as SIM with a positive D term of zero-field splitting. The longest magnetic relaxation time is 150 ms (0.2 mol% Co) at 1.8 K under a static field of 0.1 T. Temperature dependency of the relaxation time suggests suppressing magnetic relaxation by reduction of spin-spin interaction upon doping in the rigid framework. Thus, this work represents a proof of concept for the creation of a single-ion doped magnet in the MOF. This simple synthetic strategy will be widely applied for the creation of quantum magnetic materials.
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Affiliation(s)
- Masanori Wakizaka
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-Ku, Sendai, 980-8578, Japan
| | - Ryuta Ishikawa
- Department of Chemistry, Faculty of Science, Fukuoka University, 8-19-1 Nanakuma, Jonan-Ku, Fukuoka, 814-0180, Japan
| | - Hisaaki Tanaka
- Department of Applied Physics, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya, 464.-8603, Japan
| | - Shraddha Gupta
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-Ku, Sendai, 980-8578, Japan
| | - Shinya Takaishi
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-Ku, Sendai, 980-8578, Japan
| | - Masahiro Yamashita
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-Ku, Sendai, 980-8578, Japan
- School of Materials Science and Engineering, Nankai University, Tianjin, 300350, P. R. China
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29
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Allão Cassaro RA, Lahti PM, Vaz MGF, Novak MA. Lattice Solvent Engineering Improves the Stability of a Cobalt Pyrenylnitronylnitroxide Ferrimagnetic Chain. Inorg Chem 2023. [PMID: 37411011 DOI: 10.1021/acs.inorgchem.3c01543] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
Reaction of 2-(1'-pyrenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (PyrNN) with [Co(hfac)2(H2O)2] (hfac = hexafluoroacetylacetonate) in n-heptane solvent (hep) with a small amount of bromoform (CHBr3 = bf) gives the 1D ferrimagnetic complex [Co(hfac)2PyrNN]n·0.5bf·0.5hep (Co-PyrNN·bf). This chain exhibits slow magnetic relaxation with magnetic blocking below 13.4 K, presenting a magnetic hysteresis with high coercive field (51 kOe at 5.0 K) as a hard magnet. It also shows frequency-dependent behavior consistent with one dominant relaxation process with an activation barrier of Δτ/kB = (365 ± 24) K. The compound is an isomorphous variant of a previously reported ambient unstable chain made by using chloroform (CHCl3 = cf), [Co(hfac)2PyrNN]n·0.5cf·0.5hep (Co-PyrNN·cf). This shows that the variation of a magnetically inactive lattice solvent can improve the stability of analogous, void space containing single-chain magnets.
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Affiliation(s)
- Rafael A Allão Cassaro
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-909, Brazil
| | - Paul M Lahti
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Maria G F Vaz
- Instituto de Química, Universidade Federal Fluminense, Niterói, RJ 24020-150, Brazil
| | - Miguel A Novak
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-972, Brazil
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30
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Gupta SK, Rao SV, Demeshko S, Dechert S, Bill E, Atanasov M, Neese F, Meyer F. Air-stable four-coordinate cobalt(ii) single-ion magnets: experimental and ab initio ligand field analyses of correlations between dihedral angles and magnetic anisotropy. Chem Sci 2023; 14:6355-6374. [PMID: 37325133 PMCID: PMC10266464 DOI: 10.1039/d3sc00813d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 05/12/2023] [Indexed: 06/17/2023] Open
Abstract
For single-ion magnets (SIMs), understanding the effects of the local coordination environment and ligand field on magnetic anisotropy is key to controlling their magnetic properties. Here we present a series of tetracoordinate cobalt(ii) complexes of the general formula [FL2Co]X2 (where FL is a bidentate diamido ligand) whose electron-withdrawing -C6F5 substituents confer stability under ambient conditions. Depending on the cations X, these complexes adopt structures with greatly varying dihedral twist angle δ between the N-Co-N' chelate planes in the solid state (48.0 to 89.2°). AC and DC field magnetic susceptibility measurements show this to translate into very different magnetic properties, the axial zero-field splitting (ZFS) parameter D ranging from -69 cm-1 to -143 cm-1 with substantial or negligible rhombic component E, respectively. A close to orthogonal arrangement of the two N,N'-chelating σ- and π-donor ligands at the Co(ii) ion is found to raise the energy barrier for magnetic relaxation to above 400 K. Multireference ab initio methods were employed to describe the complexes' electronic structures, and the results were analyzed within the framework of ab initio ligand field theory to probe the nature of the metal-ligand bonding and spin-orbit coupling. A relationship between the energy gaps of the first few electronic transitions and the ZFS was established, and the ZFS was correlated with the dihedral angle δ as well as with the metal-ligand bonding variations, viz. the two angular overlap parameters eσ and eπs. These findings not only give rise to a Co(ii) SIM showing open hysteresis up to 3.5 K at a sweep rate of 30 Oe s-1, but they also provide design guidelines for Co(ii) complexes with favorable SIM signatures or even switchable magnetic relaxation properties.
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Affiliation(s)
- Sandeep K Gupta
- Institut für Anorganische Chemie, Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
| | - Shashank V Rao
- Max Planck Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Serhiy Demeshko
- Institut für Anorganische Chemie, Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
| | - Sebastian Dechert
- Institut für Anorganische Chemie, Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
| | - Eckhard Bill
- Max Planck Institute for Chemical Energy Conversion Stiftstrasse 34-36 45470 Mülheim an der Ruhr Germany
| | - Mihail Atanasov
- Max Planck Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences Akad. Georgi Bontchev Street 11 1113 Sofia Bulgaria
| | - Frank Neese
- Max Planck Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Franc Meyer
- Institut für Anorganische Chemie, Universität Göttingen Tammannstrasse 4 37077 Göttingen Germany
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31
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Shee J, Weber JL, Reichman DR, Friesner RA, Zhang S. On the potentially transformative role of auxiliary-field quantum Monte Carlo in quantum chemistry: A highly accurate method for transition metals and beyond. J Chem Phys 2023; 158:140901. [PMID: 37061483 PMCID: PMC10089686 DOI: 10.1063/5.0134009] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2023] Open
Abstract
Approximate solutions to the ab initio electronic structure problem have been a focus of theoretical and computational chemistry research for much of the past century, with the goal of predicting relevant energy differences to within "chemical accuracy" (1 kcal/mol). For small organic molecules, or in general, for weakly correlated main group chemistry, a hierarchy of single-reference wave function methods has been rigorously established, spanning perturbation theory and the coupled cluster (CC) formalism. For these systems, CC with singles, doubles, and perturbative triples is known to achieve chemical accuracy, albeit at O(N7) computational cost. In addition, a hierarchy of density functional approximations of increasing formal sophistication, known as Jacob's ladder, has been shown to systematically reduce average errors over large datasets representing weakly correlated chemistry. However, the accuracy of such computational models is less clear in the increasingly important frontiers of chemical space including transition metals and f-block compounds, in which strong correlation can play an important role in reactivity. A stochastic method, phaseless auxiliary-field quantum Monte Carlo (ph-AFQMC), has been shown to be capable of producing chemically accurate predictions even for challenging molecular systems beyond the main group, with relatively low O(N3 - N4) cost and near-perfect parallel efficiency. Herein, we present our perspectives on the past, present, and future of the ph-AFQMC method. We focus on its potential in transition metal quantum chemistry to be a highly accurate, systematically improvable method that can reliably probe strongly correlated systems in biology and chemical catalysis and provide reference thermochemical values (for future development of density functionals or interatomic potentials) when experiments are either noisy or absent. Finally, we discuss the present limitations of the method and where we expect near-term development to be most fruitful.
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Affiliation(s)
- James Shee
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - John L Weber
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - David R Reichman
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - Richard A Friesner
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - Shiwei Zhang
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA
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Li Y, Zeng Z, Guo Y, Liu X, Zhang YQ, Ouyang Z, Wang Z, Liu X, Zheng YZ. Synergy of Magnetic Anisotropy and Ferromagnetic Interaction Triggering a Dimeric Cr(II) Zero-Field Single-Molecule Magnet. Inorg Chem 2023; 62:6297-6305. [PMID: 37040590 DOI: 10.1021/acs.inorgchem.2c04359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
A novel CrII-dimeric complex, [CrIIN(SiiPr3)2(μ-Cl)(THF)]2 (1), has been successfully constructed using a bulky silyl-amide ligand. Single-crystal structure analysis reveals that complex 1 exhibits a binuclear motif, with a Cr2Cl2 rhombus core, where two equivalent tetra-coordinate CrII centers in the centrosymmetric unit display quasi-square planar geometry. The crystal structure has been well simulated and explored by density functional theory calculations. The axial zero-field splitting parameter (D < 0) with a small rhombic (E) value is unambiguously determined by systematic investigations of magnetic measurements, high-frequency electron paramagnetic resonance spectroscopy, and ab initio calculations. Remarkably, ac magnetic susceptibility data unveil that 1 features slow dynamic magnetic relaxation typical of single-molecule magnet behavior with Ueff = 22 K in the absence of a dc field. This increases up to 35 K under a corresponding static field. Moreover, magnetic studies and theoretical calculations point out that a non-negligible ferromagnetic coupling (FMC) exists in the dimeric Cr-Cr units of 1. The coexistence of magnetic anisotropy and FMC contributes to the first case of CrII-based single-molecule magnets (SMMs) under zero dc field.
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Affiliation(s)
- Yuzhu Li
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
| | - Zhaopeng Zeng
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
| | - Yan Guo
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
| | - Xingman Liu
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, China
| | - Zhongwen Ouyang
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhenxing Wang
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiangyu Liu
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
| | - Yan-Zhen Zheng
- Frontier Institute of Science and Technology, School of Chemistry and School of Physics, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China
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33
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Wakizaka M, Sato T, Yoshino Y, Takaishi S, Yamashita M. Intramolecular Ferromagnetism in Di-Nuclear 3 d-Transition-Metal Single-Molecule Magnets by Pseudo-Serial Arrangement. Chemistry 2023; 29:e202203421. [PMID: 36479715 DOI: 10.1002/chem.202203421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 11/30/2022] [Accepted: 12/06/2022] [Indexed: 12/12/2022]
Abstract
Di-nuclear citrate complexes, [CH6 N3 ]2 [M2 (citH)2 (H2 O)4 ] ⋅ 2H2 O (citH4 =citric acid; M=FeII (Fe-2), CoII (Co-2), and NiII (Ni-2)), are synthesized. The ligand, citH3- , is deprotonated only at the three carboxy groups, which is different from the previously reported tetra-nuclear structures with cit4- ligands. Magnetic measurements reveal that these complexes have intramolecular ferromagnetism with J=∼0 cm-1 (Ni-2), 0.02 cm-1 (Co-2), and 0.04 cm-1 (Fe-2). Co-2 and Fe-2 show slow magnetic relaxation, and are field-induced SMMs with activation energy of spin-reversal Ueff =27 cm-1 (Co-2) and 4.2 cm-1 (Fe-2). Density functional theory calculations indicate that the uniaxial anisotropy along the z-axis of each metal ion center forms the pseudo-serial arrangement, leading to intramolecular ferromagnetism via the magnetic dipole interaction. This work demonstrates the creation of ferromagnetic SMMs by the magnetic dipole engineering of 3d di-nuclear metal ion centers.
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Affiliation(s)
- Masanori Wakizaka
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-Ku, Sendai, 980-8578, Japan
| | - Tetsu Sato
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-Ku, Sendai, 980-8578, Japan
| | - Yuko Yoshino
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-Ku, Sendai, 980-8578, Japan
| | - Shinya Takaishi
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-Ku, Sendai, 980-8578, Japan
| | - Masahiro Yamashita
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-Ku, Sendai, 980-8578, Japan.,School of Materials Science and Engineering, Nankai University, Tianjin, 300350, P. R. China
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34
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Gupta S, Nielsen HH, Thiel AM, Klahn EA, Feng E, Cao HB, Hansen TC, Lelièvre-Berna E, Gukasov A, Kibalin I, Dechert S, Demeshko S, Overgaard J, Meyer F. Multi-Technique Experimental Benchmarking of the Local Magnetic Anisotropy of a Cobalt(II) Single-Ion Magnet. JACS AU 2023; 3:429-440. [PMID: 36873706 PMCID: PMC9975825 DOI: 10.1021/jacsau.2c00575] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/31/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
A comprehensive understanding of the ligand field and its influence on the degeneracy and population of d-orbitals in a specific coordination environment are crucial for the rational design and enhancement of magnetic anisotropy of single-ion magnets (SIMs). Herein, we report the synthesis and comprehensive magnetic characterization of a highly anisotropic CoII SIM, [L2Co](TBA)2 (L is an N,N'-chelating oxanilido ligand), that is stable under ambient conditions. Dynamic magnetization measurements show that this SIM exhibits a large energy barrier to spin reversal U eff > 300 K and magnetic blocking up to 3.5 K, and the property is retained in a frozen solution. Low-temperature single-crystal synchrotron X-ray diffraction used to determine the experimental electron density gave access to Co d-orbital populations and a derived U eff, 261 cm-1, when the coupling between the d x 2 - y 2 and dxy orbitals is taken into account, in very good agreement with ab initio calculations and superconducting quantum interference device results. Powder and single-crystal polarized neutron diffraction (PNPD, PND) have been used to quantify the magnetic anisotropy via the atomic susceptibility tensor, revealing that the easy axis of magnetization is pointing along the N-Co-N' bisectors of the N,N'-chelating ligands (3.4° offset), close to the molecular axis, in good agreement with complete active space self-consistent field/N-electron valence perturbation theory to second order ab initio calculations. This study provides benchmarking for two methods, PNPD and single-crystal PND, on the same 3d SIM, and key benchmarking for current theoretical methods to determine local magnetic anisotropy parameters.
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Affiliation(s)
- Sandeep
K. Gupta
- Universität
Göttingen, Institut für Anorganische Chemie, Tammannstraße 4, D-37077Göttingen, Germany
| | - Hannah H. Nielsen
- Department
of Chemistry, Aarhus University, Langelandsgade 140, DK-8000Aarhus C, Denmark
| | - Andreas M. Thiel
- Department
of Chemistry, Aarhus University, Langelandsgade 140, DK-8000Aarhus C, Denmark
| | - Emil A. Klahn
- Department
of Chemistry, Aarhus University, Langelandsgade 140, DK-8000Aarhus C, Denmark
| | - Erxi Feng
- Neutron
Scattering Division, Oak Ridge National
Laboratory, Oak Ridge, Tennessee37831, United States
| | - Huibo B. Cao
- Neutron
Scattering Division, Oak Ridge National
Laboratory, Oak Ridge, Tennessee37831, United States
| | - Thomas C. Hansen
- Institut
Laue-Langevin (ILL), 71 Avenue des Martyrs, 38042Grenoble, France
| | | | - Arsen Gukasov
- Laboratoire
Léon Brillouin (LLB), CEA CE de Saclay, Gif sur Yvette91191, France
| | - Iurii Kibalin
- Laboratoire
Léon Brillouin (LLB), CEA CE de Saclay, Gif sur Yvette91191, France
| | - Sebastian Dechert
- Universität
Göttingen, Institut für Anorganische Chemie, Tammannstraße 4, D-37077Göttingen, Germany
| | - Serhiy Demeshko
- Universität
Göttingen, Institut für Anorganische Chemie, Tammannstraße 4, D-37077Göttingen, Germany
| | - Jacob Overgaard
- Department
of Chemistry, Aarhus University, Langelandsgade 140, DK-8000Aarhus C, Denmark
| | - Franc Meyer
- Universität
Göttingen, Institut für Anorganische Chemie, Tammannstraße 4, D-37077Göttingen, Germany
- Universität
Göttingen, International Center for Advanced Studies of Energy
Conversion (ICASEC), Tammannstraße 6, D-37077Göttingen, Germany
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35
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Weller R, Atanasov M, Demeshko S, Chen TY, Mohelsky I, Bill E, Orlita M, Meyer F, Neese F, Werncke CG. On the Single-Molecule Magnetic Behavior of Linear Iron(I) Arylsilylamides. Inorg Chem 2023; 62:3153-3161. [PMID: 36744742 DOI: 10.1021/acs.inorgchem.2c04050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The rational design of 3d-metal-based single-molecule magnets (SMM) requires a fundamental understanding of their intrinsic electronic and structural properties and how they translate into experimentally observable features. Here, we determined the magnetic properties of the linear iron(I) silylamides K{crypt}[FeL2] and [KFeL2] (L = -N(Dipp)SiMe3; crypt = 4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]hexacosan). For the former, slow-relaxation of the magnetization with a spin reversal barrier of Ueff = 152 cm-1 as well as a closed-waist magnetic hysteresis and magnetic blocking below 2.5 K are observed. For the more linear [KFeL2], in which the potassium cation is encapsulated by the aryl substituents of the amide ligands, the relaxation barrier and the blocking temperature increase to Ueff = 184 cm-1 and TB = 4.5 K, respectively. The increase is rationalized by a more pronounced axial anisotropy in [KFeL2] determined by dc-SQUID magnetometry. The effective relaxation barrier of [KFeL2] is in agreement with the energy spacing between the ground and first-excited magnetic states, as obtained by field-dependent IR-spectroscopy (178 cm-1), magnetic measurements (208 cm-1), as well as theoretical analysis (212 cm-1). In comparison with the literature, the results show that magnetic coercivity in linear iron(I) silylamides is driven by the degree of linearity in conjunction with steric encumbrance, whereas the ligand symmetry is a marginal factor.
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Affiliation(s)
- Ruth Weller
- Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße 4, 35043Marburg, Germany
| | - Mihail Atanasov
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470Mülheim an der Ruhr, Germany.,Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Akad.Georgi Bontchev Street, Bl.11, 1113Sofia, Bulgaria
| | - Serhiy Demeshko
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077Göttingen, Germany
| | - Ting-Yi Chen
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077Göttingen, Germany
| | - Ivan Mohelsky
- LAB National des Champs Magnétiques Intenses, LNCMI─CNRS, 25 Martyrs Avenue, BP 166, 38042Grenoble Cedex 9, France
| | - Eckhard Bill
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470Mülheim an der Ruhr, Germany
| | - Milan Orlita
- LAB National des Champs Magnétiques Intenses, LNCMI─CNRS, 25 Martyrs Avenue, BP 166, 38042Grenoble Cedex 9, France.,Institute of Physics, Charles University in Prague, Ke Karlovu 5, CZ-12116Prague, Czech Republic
| | - Franc Meyer
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077Göttingen, Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470Mülheim an der Ruhr, Germany
| | - C Gunnar Werncke
- Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße 4, 35043Marburg, Germany
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36
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Ferentinos E, Tzeli D, Sottini S, Groenen EJJ, Ozerov M, Poneti G, Kaniewska-Laskowska K, Krzystek J, Kyritsis P. Magnetic anisotropy and structural flexibility in the field-induced single ion magnets [Co{(OPPh 2)(EPPh 2)N} 2], E = S, Se, explored by experimental and computational methods. Dalton Trans 2023; 52:2036-2050. [PMID: 36692040 PMCID: PMC9926333 DOI: 10.1039/d2dt03335f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 01/14/2023] [Indexed: 01/25/2023]
Abstract
During the last few years, a large number of mononuclear Co(II) complexes of various coordination geometries have been explored as potential single ion magnets (SIMs). In the work presented herein, the Co(II) S = 3/2 tetrahedral [Co{(OPPh2)(EPPh2)N}2], E = S, Se, complexes (abbreviated as CoO2E2), bearing chalcogenated mixed donor-atom imidodiphosphinato ligands, were studied by both experimental and computational techniques. Specifically, direct current (DC) magnetometry provided estimations of their zero-field splitting (zfs) axial (D) and rhombic (E) parameter values, which were more accurately determined by a combination of far-infrared magnetic spectroscopy and high-frequency and -field EPR spectroscopy studies. The latter combination of techniques was also implemented for the S = 3/2 tetrahedral [Co{(EPiPr2)2N}2], E = S, Se, complexes, confirming the previously determined magnitude of their zfs parameters. For both pairs of complexes (E = S, Se), it is concluded that the identity of the E donor atom does not significantly affect their zfs parameters. High-resolution multifrequency EPR studies of CoO2E2 provided evidence of multiple conformations, which are more clearly observed for CoO2Se2, in agreement with the structural disorder previously established for this complex by X-ray crystallography. The CoO2E2 complexes were shown to be field-induced SIMs, i.e., they exhibit slow relaxation of magnetization in the presence of an external DC magnetic field. Advanced quantum-chemical calculations on CoO2E2 provided additional insight into their electronic and structural properties.
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Affiliation(s)
- Eleftherios Ferentinos
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, GR-15771 Athens, Greece.
| | - Demeter Tzeli
- Physical Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, GR-15771 Athens, Greece
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Ave., GR-11635 Athens, Greece
| | - Silvia Sottini
- Huygens-Kamerlingh Onnes Laboratory, Department of Physics, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
| | - Edgar J J Groenen
- Huygens-Kamerlingh Onnes Laboratory, Department of Physics, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA.
| | - Giordano Poneti
- Instituto de Química, Universidade Federal do Rio de Janeiro, 21941-909 Rio de Janeiro, Brazil.
| | - Kinga Kaniewska-Laskowska
- Department of Inorganic Chemistry, Faculty of Chemistry, Gdańsk University of Technology, G. Narutowicza St. 11/12, Gdańsk PL-80-233, Poland
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA.
| | - Panayotis Kyritsis
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, GR-15771 Athens, Greece.
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37
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Mansikkamäki A. Theoretical study of phenylbismuth anion as a blueprint for main-group single-molecule magnets. Chem Commun (Camb) 2023; 59:1837-1840. [PMID: 36722929 DOI: 10.1039/d3cc00042g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The hypothetical [BiPh]- anion obtained by a one-electron reduction from the respective bismuthinidene is proposed as a basis for constructing single-molecule magnets (SMMs) consisting purely of main-group elements. Based on high-level quantum-chemical calculations, the [BiPh]- anion is predicted to be a SMM with an effective barrier of 6418 cm-1 for the relaxation of magnetization. This barrier is much larger than any effective barrier observed so far in any experimentally characterized SMM. The reduction potential for the [BiPh]-/BiPh couple is calculated as -1.5 V, which implies that the [BiPh]- moiety is accessible from stable bismuthinidenes containing a BiPh moiety and sufficient steric protection for the reactive Bi atom. Thus, [BiPh]- provides a blueprint for the realization of purely main-group SMMs which can surpass in their properties the best known dysprosium-based SMMs.
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Affiliation(s)
- Akseli Mansikkamäki
- NMR Research Unit, University of Oulu, P.O. Box 8000, Oulu, FI-90014, Finland.
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38
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Approaching the uniaxiality of magnetic anisotropy in single-molecule magnets. Sci China Chem 2023. [DOI: 10.1007/s11426-022-1423-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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39
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Noor A. Recent developments in two coordinate transition metal chemistry. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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40
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Landart-Gereka A, Quesada-Moreno MM, Palacios MA, Díaz-Ortega IF, Nojiri H, Ozerov M, Krzystek J, Colacio E. Pushing up the easy-axis magnetic anisotropy and relaxation times in trigonal prismatic Co II mononuclear SMMs by molecular structure design. Chem Commun (Camb) 2023; 59:952-955. [PMID: 36597978 DOI: 10.1039/d2cc06012d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The replacement of pyridine by 1-methyl-imidazol in the arms of a N6-tripodal ligand allows preparing two new CoII complexes with quasi-ideal triangular prismatic geometry, which behave as SIMs (Single Ion Magnets) at zero dc field with enhanced axial magnetic anisotropy, magnetic relaxation times and magnetic hysteresis.
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Affiliation(s)
- Aritz Landart-Gereka
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
| | - María Mar Quesada-Moreno
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
| | - María A Palacios
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
| | - Ismael F Díaz-Ortega
- Institute for Materials Research, Tohoku University, Katahira, Sendai, 980-8577, Japan.,Departamento de Química y Física-CIESOL, Universidad de Almería, Ctra. Sacramento s/n, 04120, Almería, Spain
| | - Hiroyuki Nojiri
- Institute for Materials Research, Tohoku University, Katahira, Sendai, 980-8577, Japan
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | - Enrique Colacio
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
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41
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Mironov VS, Bazhenova TA, Manakin YV, Yagubskii EB. Pentagonal-bipyramidal 4d and 5d complexes with unquenched orbital angular momentum as a unique platform for advanced single-molecule magnets: current state and perspectives. Dalton Trans 2023; 52:509-539. [PMID: 36537237 DOI: 10.1039/d2dt02954e] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This article overviews the current state and prospects of the concept of advanced single-molecule magnets (SMMs) based on low-spin (S = 1/2) pentagonal-bipyramidal (PBP) 4d3 and 5d3 complexes with unquenched orbital angular momentum. This approach is based on the unique property of PBP 4d3 and 5d3 complexes to cause highly anisotropic spin coupling of perfect uniaxial symmetry, -JzSziSzj - Jxy(SxiSxj + SyiSyj), regardless of the local geometric symmetry. The M(4d/5d)-M(3d) exchange-coupled pairs in the apical positions of the PBP complexes produce Ising-type exchange interactions (|Jz| > |Jxy|), which serve as a powerful source of uniaxial magnetic anisotropy of a SMM cluster. In polynuclear heterometallic 4d/5d-3d complexes embodying PBP 4d/5d units and high-spin 3d ions, anisotropic Ising-type exchange interactions produce a double-well potential with high energy barriers Ueff, which is controlled by the anisotropic exchange parameters Jz, Jxy. Theoretical analysis shows that the barrier is proportional to the difference |Jz - Jxy| and to the number n of the apical 4d/5d-3d pairs in a SMM cluster, Ueff ∝ |Jz - Jxy|n, which provides an opportunity to scale up the barrier Ueff and blocking temperature TB up to the record values. A novel family of 4d/5d complexes with forced PBP coordination provided by structurally rigid planar pentadentate Schiff-base ligands in the equatorial plane is discussed as a better alternative to the cyanometallates. The possibility of a significant increase in the anisotropic exchange parameters Jz, Jxy in PBP complexes with monoatomic apical μ-bridging ligands is examined. The basic principles of molecular engineering the highest barrier through anisotropic exchange interactions of PBP 4d/5d complexes are formulated. The theoretical and experimental results taken together indicate that the concept of high-performance SMMs based on 4d/5d PBP complexes with unquenched orbital angular momentum is an attractive alternative to the currently dominant lanthanide-based SMM strategy.
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Affiliation(s)
- V S Mironov
- Institute of Problems of Chemical Physics RAS, Federal Research Center of Problems of Chemical Physics and Medical Chemistry RAS, Chernogolovka 142432, Russia. .,Shubnikov Institute of Crystallography of Federal Scientific Research Centre "Crystallography and Photonics" RAS, Moscow, Russia
| | - T A Bazhenova
- Institute of Problems of Chemical Physics RAS, Federal Research Center of Problems of Chemical Physics and Medical Chemistry RAS, Chernogolovka 142432, Russia.
| | - Yu V Manakin
- Institute of Problems of Chemical Physics RAS, Federal Research Center of Problems of Chemical Physics and Medical Chemistry RAS, Chernogolovka 142432, Russia.
| | - E B Yagubskii
- Institute of Problems of Chemical Physics RAS, Federal Research Center of Problems of Chemical Physics and Medical Chemistry RAS, Chernogolovka 142432, Russia.
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42
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Manakin YV, Mironov VS, Bazhenova TA, Yakushev IA, Gilmutdinov IF, Simonov SV, Yagubskii EB. (Et 4N)[W III(DAPBH)(CN) 2], the first pentagonal-bipyramidal W(III) complex with unquenched orbital angular momentum: a novel Ising-type magnetic building block for single-molecule magnets. Chem Commun (Camb) 2023; 59:643-646. [PMID: 36537239 DOI: 10.1039/d2cc05998c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The first pentagonal-bipyramidal tungsten(III) complex (Et4N)[WIII(DAPBH)(CN)2] with a N3O2-type Schiff-base ligand and two apical cyanide groups was synthesized and characterized structurally and magnetically. The complex has a low-spin (S = 1/2) ground state and features unquenched orbital angular momentum ML = ±1 causing very strong Ising-type magnetic anisotropy.
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Affiliation(s)
- Yu V Manakin
- Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry RAS, Chernogolovka, Russia.
| | - V S Mironov
- Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry RAS, Chernogolovka, Russia. .,Shubnikov Institute of Crystallography of Federal Scientific Research Centre "Crystallography and Photonics" RAS, Moscow, Russia.
| | - T A Bazhenova
- Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry RAS, Chernogolovka, Russia.
| | - I A Yakushev
- Kurnakov Institute of General and Inorganic Chemistry, Moscow, Russia.,National Research Center "Kurchatov Institute", Moscow, Russia
| | - I F Gilmutdinov
- Institute of Physics, Kazan Federal University, Kazan, Russia
| | - S V Simonov
- Institute of Solid State Physics, Chernogolovka, Russia
| | - E B Yagubskii
- Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry RAS, Chernogolovka, Russia.
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43
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Belov AS, Novikov VV, Vologzhanina AV, Pavlov AA, Bogomyakov AS, Zubavichus YV, Svetogorov RD, Zelinskii GE, Voloshin YZ. Synthesis, crystal polymorphism and spin crossover behavior of adamantylboron-capped cobalt(II) hexachloroclathrochelate and its transformation into the Co IIICo IICo III-bis-macrobicyclic derivative. Dalton Trans 2023; 52:347-359. [PMID: 36511081 DOI: 10.1039/d2dt03300c] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Fast crystallization of the monoclathrochelate cobalt(II) intracomplex [Co(Cl2Gm)3(BAd)2] (where Cl2Gm2- is a dichloroglyoxime dianion and BAd is an adamantylboron capping group, 1), initially obtained by the direct template condensation of the corresponding chelating α-dioximate and cross-linking ligand synthons on the Co2+ ion as a matrix, from benzene or dichloromethane afforded its structural triclinic and hexagonal polymorphs. Its prolonged recrystallization from dichloromethane under air atmosphere and sunlight irradiation unexpectedly gave the crystals of the CoIIICoIICoIII-trinuclear dodecachloro-bis-clathrochelate intracomplex [[CoIII(Cl2Gm)3(BAd)]2CoII] (2), the molecule of which consists of two macrobicyclic frameworks with encapsulated low-spin (LS) Co3+ ions, which are cross-linked by a μ3-bridging Co2+ ion as a bifunctional Lewis-acidic center. The most plausible pathway of such a 1 → 2 transformation is based on the photoinitiated radical oxidation of dichloromethane with air oxygen giving the reactive species. Cobalt(II) monoclathrochelate 1 was found to undergo a temperature-induced spin crossover (SCO) both in its solutions and in the solid state. In spite of the conformational rigidity of the corresponding quasiaromatic diboron-capped tris-α-dioximate framework, the main parameters of this SCO transition (i.e., its completeness and gradual character) are strongly affected by the nature of the used solvent (in the case of its solutions) and by the structural polymorphism of its crystals (in the solid state). In the latter case, the LS state (S = 1/2) of this complex is more thermally stable and, therefore, the cobalt(II)-centered 1/2 → 3/2 SCO is more gradual than that in solutions.
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Affiliation(s)
- Alexander S Belov
- Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, 31 Leninsky pr., 119991 Moscow, Russia. .,Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences, 28-1 Vavilova st., 119334 Moscow, Russia
| | - Valentin V Novikov
- Moscow Institute of Physics and Technology, 141700 Moscow Region, Russia
| | - Anna V Vologzhanina
- Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences, 28-1 Vavilova st., 119334 Moscow, Russia
| | - Alexander A Pavlov
- Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences, 28-1 Vavilova st., 119334 Moscow, Russia.,National Research University Higher School of Economics, 101000 Moscow, Russia
| | - Artem S Bogomyakov
- International Tomography Center, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Yan V Zubavichus
- Synchrotron Radiation Facility SKIF, G.K. Boreskov Institute of Catalysis of the Siberian Branch of the Russian Academy of Sciences, 1 Nikolskii pr., 630559 Koltsovo, Russia
| | | | - Genrikh E Zelinskii
- Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, 31 Leninsky pr., 119991 Moscow, Russia. .,Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences, 28-1 Vavilova st., 119334 Moscow, Russia
| | - Yan Z Voloshin
- Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, 31 Leninsky pr., 119991 Moscow, Russia. .,Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences, 28-1 Vavilova st., 119334 Moscow, Russia
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44
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Mondal S, Lunghi A. Unraveling the Contributions to Spin-Lattice Relaxation in Kramers Single-Molecule Magnets. J Am Chem Soc 2022; 144:22965-22975. [PMID: 36490388 PMCID: PMC9782788 DOI: 10.1021/jacs.2c08876] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The study of how spin interacts with lattice vibrations and relaxes to equilibrium provides unique insights into its chemical environment and the relation between electronic structure and molecular composition. Despite its importance for several disciplines, ranging from magnetic resonance to quantum technologies, a convincing interpretation of spin dynamics in crystals of magnetic molecules is still lacking due to the challenging experimental determination of the correct spin relaxation mechanism. We apply ab initio spin dynamics to a series of 12 coordination complexes of Co2+ and Dy3+ ions selected among ∼240 compounds that largely cover the literature on single-molecule magnets and well represent different regimes of spin relaxation. Simulations reveal that the Orbach spin relaxation rate of known compounds mostly depends on the ions' zero-field splitting and little on the details of molecular vibrations. Raman relaxation is instead found to be also significantly affected by the features of low-energy phonons. These results provide a complete understanding of the factors limiting spin lifetime in single-molecule magnets and revisit years of experimental investigations by making it possible to transparently distinguish Orbach and Raman relaxation mechanisms.
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45
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Shao D, Zhou Y, Yang X, Yue J, Ming S, Wei XQ, Tian Z. Supramolecular encapsulation of hexaaquacobalt(II) cations in a hydrogen-bonded framework for slow magnetic relaxation and high proton conduction. Dalton Trans 2022; 51:18514-18519. [PMID: 36440615 DOI: 10.1039/d2dt03278c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The supramolecular assembly of hexaaquacobalt(II) nitrate and a tetradentate carboxylate ligand resulted in the isolation of a cobalt hydrogen-bonded organic framework (HOF). Variable-temperature X-ray diffraction experiments reveal high thermal stability of the framework sustained by charge-assisted, multiple hydrogen bonding interactions with the co-former. Interestingly, the material shows field-induced slow relaxation of magnetization originating from the magnetically anisotropic Co2+ ions within the supramolecular framework, revealing a rare single-ion magnet (SIM) HOF. Additionally, the HOF also exhibits high proton conductivity above 100 °C due to the extensive H-bond networks and high content of water and carboxylate within the material. More importantly, these results not only observe the magnetic and electrical properties of an old molecule but also demonstrate a significant turn-on effect of multifunctionalities from non-functional synthons achieved in a supramolecular approach.
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Affiliation(s)
- Dong Shao
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China. .,State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing, 210023, P. R. China
| | - Yue Zhou
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China.
| | - Xiaodong Yang
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China.
| | - Jing Yue
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China.
| | - Shujun Ming
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China.
| | - Xiao-Qin Wei
- Department of Material Science and Engineering, Shanxi Province Collaborative Innovation Center for Light Materials Modification and Application, Jinzhong University, Jinzhong, 030619, P. R. China
| | - Zhengfang Tian
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China.
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46
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Observation of field-induced single-molecule magnet behavior in an octahedrally coordinated binuclear Co2 compound. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2022.121200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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47
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Huang XC, Yong W, Moorthy S, Su ZY, Kong JJ, Kumar Singh S. A pentagonal bipyramidal Co(II) single-ion magnet based on an asymmetric tetradentate ligand with easy plane anisotropy. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.116275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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48
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Briganti M, Serrano G, Poggini L, Sorrentino AL, Cortigiani B, de Camargo LC, Soares JF, Motta A, Caneschi A, Mannini M, Totti F, Sessoli R. Mixed-Sandwich Titanium(III) Qubits on Au(111): Electron Delocalization Ruled by Molecular Packing. NANO LETTERS 2022; 22:8626-8632. [PMID: 36256878 PMCID: PMC9650780 DOI: 10.1021/acs.nanolett.2c03161] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/07/2022] [Indexed: 06/15/2023]
Abstract
Organometallic sandwich complexes are versatile molecular systems that have been recently employed for single-molecule manipulation and spin sensing experiments. Among related organometallic compounds, the mixed-sandwich S = 1/2 complex (η8-cyclooctatetraene)(η5-cyclopentadienyl)titanium, here [CpTi(cot)], has attracted interest as a spin qubit because of the long coherence time. Here the structural and chemical properties of [CpTi(cot)] on Au(111) are investigated at the monolayer level by experimental and computational methods. Scanning tunneling microscopy suggests that adsorption occurs in two molecular orientations, lying and standing, with a 3:1 ratio. XPS data evidence that a fraction of the molecules undergo partial electron transfer to gold, while our computational analysis suggests that only the standing molecules experience charge delocalization toward the surface. Such a phenomenon depends on intermolecular interactions that stabilize the molecular packing in the monolayer. This orientation-dependent molecule-surface hybridization opens exciting perspectives for selective control of the molecule-substrate spin delocalization in hybrid interfaces.
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Affiliation(s)
- Matteo Briganti
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
- Department
of Chemistry, Federal University of Parana, Centro Politecnico, Jardim das Americas, 81530-900 Curitiba, PR Brazil
| | - Giulia Serrano
- Department
of Industrial Engineering (DIEF) and INSTM Research Unit, University of Florence, Via di Santa Marta, 3, 50139 Florence, Italy
| | - Lorenzo Poggini
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
- Institute
for Chemistry of OrganoMetallic Compounds (ICCOM-CNR), Via Madonna del Piano, 50019 Sesto Fiorentino (FI) Italy
| | - Andrea Luigi Sorrentino
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
- Department
of Industrial Engineering (DIEF) and INSTM Research Unit, University of Florence, Via di Santa Marta, 3, 50139 Florence, Italy
| | - Brunetto Cortigiani
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
| | - Luana Carol de Camargo
- Department
of Chemistry, Federal University of Parana, Centro Politecnico, Jardim das Americas, 81530-900 Curitiba, PR Brazil
| | - Jaísa Fernandes Soares
- Department
of Chemistry, Federal University of Parana, Centro Politecnico, Jardim das Americas, 81530-900 Curitiba, PR Brazil
| | - Alessandro Motta
- “La
Sapienza” and INSTM Research Unit, University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Andrea Caneschi
- Department
of Industrial Engineering (DIEF) and INSTM Research Unit, University of Florence, Via di Santa Marta, 3, 50139 Florence, Italy
| | - Matteo Mannini
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
| | - Federico Totti
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
| | - Roberta Sessoli
- Department
of Chemistry “U. Schiff” (DICUS) and INSTM Research
Unit, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (FI), Italy
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49
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Jing Y, Wang J, Kong M, Wang GJ, Zhang YQ, Song Y. Detailed Magnetic Properties and Theoretical Calculation in Ferromagnetic Coupling DyIII-MII 3d-4f Complexes Based on a 1,4,7,10-tetraazacyclododecane Derivative. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2022.121301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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50
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Lunghi A, Sanvito S. Computational design of magnetic molecules and their environment using quantum chemistry, machine learning and multiscale simulations. Nat Rev Chem 2022; 6:761-781. [PMID: 37118096 DOI: 10.1038/s41570-022-00424-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2022] [Indexed: 11/09/2022]
Abstract
Having served as a playground for fundamental studies on the physics of d and f electrons for almost a century, magnetic molecules are now becoming increasingly important for technological applications, such as magnetic resonance, data storage, spintronics and quantum information. All of these applications require the preservation and control of spins in time, an ability hampered by the interaction with the environment, namely with other spins, conduction electrons, molecular vibrations and electromagnetic fields. Thus, the design of a novel magnetic molecule with tailored properties is a formidable task, which does not only concern its electronic structures but also calls for a deep understanding of the interaction among all the degrees of freedom at play. This Review describes how state-of-the-art ab initio computational methods, combined with data-driven approaches to materials modelling, can be integrated into a fully multiscale strategy capable of defining design rules for magnetic molecules.
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