1
|
Autillo M, Illy MC, Briscese L, Islam MA, Bolvin H, Berthon C. Paramagnetic Properties of [An IV(NO 3) 6] 2- Complexes (An = U, Np, Pu) Probed by NMR Spectroscopy and Quantum Chemical Calculations. Inorg Chem 2024. [PMID: 38951989 DOI: 10.1021/acs.inorgchem.4c01694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/03/2024]
Abstract
Actinide +IV complexes with six nitrates [AnIV(NO3)6]2- (An = Th, U, Np, and Pu) have been studied by 15N and 17O NMR spectroscopy in solution and first-principles calculations. Magnetic susceptibilities were evaluated experimentally using the Evans method and are in good agreement with the ab initio values. The evolution in the series of the crystal field parameters deduced from ab initio calculations is discussed. The NMR paramagnetic shifts are analyzed based on ab initio calculations. Because the cubic symmetry of the complex quenches the dipolar contribution, they are only of Fermi contact origin. They are evaluated from first-principles based on a complete active space/density functional theory (DFT) strategy, in good accordance with the experimental one. The ligand hyperfine coupling constants are deduced from paramagnetic shifts and calculated using unrestricted DFT. The latter are decomposed in terms of the contribution of molecular orbitals. It highlights two pathways for the delocalization of the spin density from the metallic open-shell 5f orbitals to the NMR active nuclei, either through the valence 5f hybridized with 6d to the valence 2p molecular orbitals of the ligands, or by spin polarization of the metallic 6p orbitals which interact with the 2s-based molecular orbitals of the ligands.
Collapse
Affiliation(s)
- Matthieu Autillo
- CEA, DES, ISEC, DPME, Univ. Montpellier, Bagnols-sur-Cèze 30207, France
| | - Marie-Claire Illy
- CEA, DES, ISEC, DMRC, Univ. Montpellier, Bagnols-sur-Cèze 30207, France
| | - Luca Briscese
- CEA, DES, ISEC, DMRC, Univ. Montpellier, Bagnols-sur-Cèze 30207, France
| | - Md Ashraful Islam
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs─CRMN, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Hélène Bolvin
- Laboratoire de Chimie et Physique Quantiques, CNRS, Université Toulouse III, 118 route de Narbonne, 31062 Toulouse, France
| | - Claude Berthon
- CEA, DES, ISEC, DMRC, Univ. Montpellier, Bagnols-sur-Cèze 30207, France
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
Pissas M, Ferentinos E, Kyritsis P, Sanakis Y. Field-Induced Slow Magnetization Relaxation of a Tetrahedral S=2 Fe IIS 4-Containing Complex. Chempluschem 2024:e202400109. [PMID: 38727531 DOI: 10.1002/cplu.202400109] [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: 02/06/2024] [Revised: 05/08/2024] [Indexed: 06/09/2024]
Abstract
In the work described herein, the spin relaxation properties of the mononuclear tetrahedral S=2 [Fe{(SPiPr2)2N}2] complex (1) were studied by employing static and dynamic magnetic measurements at liquid helium temperatures. In the absence of an external direct current (DC) magnetic field, 1 exhibits fast magnetization relaxation. However, in the presence of external magnetic fields of a few kOe, slow relaxation is induced as monitored by alternating current (AC) magnetic susceptibility measurements up to 10 kHz, in the temperature range 2-5 K. Analysis of the temperature dependence of the corresponding relaxation time reveals contributions by Quantum Tunnelling of Magnetization, and the Direct and Orbach processes in the magnetization relaxation mechanism of 1. The energy barrier, Ueff, of the Orbach process, as determined by this analysis, is compared with that related to the zero-field splitting parameters of 1 which were previously determined by high- frequency and -field electron paramagnetic resonance and Mössbauer spectroscopies.
Collapse
Affiliation(s)
- Michael Pissas
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, 15341, Ag. Paraskevi, Attiki, Greece
| | - Eleftherios Ferentinos
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, 15571, Athens, Greece
| | - Panayotis Kyritsis
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, 15571, Athens, Greece
| | - Yiannis Sanakis
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, 15341, Ag. Paraskevi, Attiki, Greece
| |
Collapse
|
4
|
Van Stappen C, Van Kuiken BE, Mörtel M, Ruotsalainen KO, Maganas D, Khusniyarov MM, DeBeer S. Correlating Valence and 2p3d RIXS Spectroscopies: A Ligand-Field Study of Spin-Crossover Iron(II). Inorg Chem 2024; 63:7386-7400. [PMID: 38587408 DOI: 10.1021/acs.inorgchem.4c00435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
The molecular spin-crossover phenomenon between high-spin (HS) and low-spin (LS) states is a promising route to next-generation information storage, sensing applications, and molecular spintronics. Spin-crossover complexes also provide a unique opportunity to study the ligand field (LF) properties of a system in both HS and LS states while maintaining the same ligand environment. Presently, we employ complementing valence and core-level spectroscopic methods to probe the electronic excited-state manifolds of the spin-crossover complex [FeII(H2B(pz)2)2phen]0. Light-induced excited spin-state trapping (LIESST) at liquid He temperatures is exploited to characterize magnetic and spectroscopic properties of the photoinduced HS state using SQUID magnetometry and magnetic circular dichroism spectroscopy. In parallel, Fe 2p3d RIXS spectroscopy is employed to examine the ΔS = 0, 1 excited LF states. These experimental studies are combined with state-of-the-art CASSCF/NEVPT2 and CASCI/NEVPT2 calculations characterizing the ground and LF excited states. Analysis of the acquired LF information further supports the notion that the spin-crossover of [FeII(H2B(pz)2)2phen]0 is asymmetric, evidenced by a decrease in eπ in the LS state. The results demonstrate the power of cross-correlating spectroscopic techniques with high and low LF information content to make accurate excited-state assignments, as well as the current capabilities of ab initio theory in interpreting these electronic properties.
Collapse
Affiliation(s)
- Casey Van Stappen
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Benjamin E Van Kuiken
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Max Mörtel
- Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstrasse 1, 91058 Erlangen, Germany
| | - Kari O Ruotsalainen
- Synchrotron SOLEIL, L'Orme des Merisiers, Départementale 128, 91190 Saint-Aubin, France
| | - Dimitrios Maganas
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Marat M Khusniyarov
- Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstrasse 1, 91058 Erlangen, Germany
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
Islam MA, Berthon C, Jung J, Bolvin H. Bonding and Magnetic Trends in the [An III(DPA) 3] 3- Series Compared to the Ln(III) and An(IV) Analogues. Inorg Chem 2023; 62:17254-17264. [PMID: 37818639 DOI: 10.1021/acs.inorgchem.3c02482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/12/2023]
Abstract
The crystal field parameters are determined from first-principles calculations in the [AnIII(DPA)3]3- series, completing previous work on the [LnIII(DPA)3]3- and [AnIV(DPA)3]2- series. The crystal field strength parameter follows the Ln(III) < An(III) < An(IV) trend. The parameters deduced at the orbital level decrease along the series, while J-mixing strongly impacts the many-electron parameters, especially for the Pu(III) complex. We further compile the available data for the three series. In some aspects, An(III) complexes are closer to Ln(III) than to An(IV) complexes with regard to the geometrical structure and bonding descriptors. At the beginning of the series, up to Pu(III), there is a quantitative departure from the free ion, especially for the Pa(III) complex. The magnetic properties of the actinides keep the trends of the lanthanides; in particular, the axial magnetic susceptibility follows Bleaney's theory qualitatively.
Collapse
Affiliation(s)
- Md Ashraful Islam
- Laboratoire de Chimie et Physique Quantiques, CNRS, Université Toulouse III, 118 Route de Narbonne, 31062 Toulouse, France
| | - Claude Berthon
- CEA, DES, ISEC, DMRC, Univ Montpellier, Marcoule, 30207 Bagnols-sur-Cèze, France
| | - Julie Jung
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Hélène Bolvin
- Laboratoire de Chimie et Physique Quantiques, CNRS, Université Toulouse III, 118 Route de Narbonne, 31062 Toulouse, France
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Zhang D, Truhlar DG. An Accurate Density Coherence Functional for Hybrid Multiconfiguration Density Coherence Functional Theory. J Chem Theory Comput 2023; 19:6551-6556. [PMID: 37708640 DOI: 10.1021/acs.jctc.3c00741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023]
Abstract
We present hybrid multiconfiguration density coherence functional theory (HMC-DCFT), and we optimize a density coherence functional by parametrization against a diverse data set of 59 bond energies and 60 barrier heights. We compare the results to calculations on the same data set by CASSCF, CASPT2, six Kohn-Sham and hybrid Kohn-Sham exchange-correlation functionals, and three on-top functionals for pair-density functional theory (PDFT) and hybrid PDFT. The new functional has better accuracy than all compared methods.
Collapse
Affiliation(s)
- Dayou Zhang
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Donald G Truhlar
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| |
Collapse
|
10
|
Ghosh R, Sarkar S, Jana Y, Piwowarska D, Gnutek P, Rudowicz C. Eu 3+ ions as a crystal-field probe for low-symmetry sites in doped phosphors - a case study: Eu 3+ at triclinic sites in Li 6RE(BO 3) 3 (RE = Y, Gd), YBO 3 and ZnO and at trigonal sites in YAl 3(BO 3) 4. Phys Chem Chem Phys 2023; 25:25537-25551. [PMID: 37712933 DOI: 10.1039/d3cp03090c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023]
Abstract
We present crystal-field (CF) calculations of energy levels (Ei) of Eu3+ ions doped in various hosts aimed at exploring the low-symmetry properties of CF parameters (CFPs) and reliability of CFP modelling with decreasing site symmetry. The hosts studied are: Li6Y(BO3)3, Li6Gd(BO3)3, YBO3, and ZnO with Eu3+ at triclinic sites; YAl3(BO3)4 with Eu3+ ions at trigonal D3 symmetry. Two independent CFP modelling approaches utilizing the hosts' structural data are employed: the exchange charge model (ECM) and the superposition model (SPM). We adopt the Eu3+ actual site symmetry and not the approximated one. The Ei values calculated using CFPs modelled by the ECM and SPM mutually agree with the observed ones. For triclinic symmetry, the ECM/CFPs and SPM/CFPs were numerically distinct, yet turned out to be physically equivalent yielding identical rotational invariants, Sk (k = 2, 4, 6) and Ei. For trigonal symmetry, both CFP sets agree numerically, thus Sk and Ei are identical. This disparity poses a dilemma, since the modified crystallographic axis system was used in both approaches. The standardization of the triclinic CFPs using the 3DD package was performed to solve this dilemma. It has enabled discussing standardization aspects in experimental and computed CFP sets and elucidating intricate low-symmetry aspects inherent in CFP sets. Understanding of low-symmetry aspects in CF studies may bring about a better interpretation of the spectroscopic and magnetic properties of rare-earth ion doped host crystals. Thus, our study could provide more deep insights into the importance of clear definitions of axis systems and adequate treatment of actual site symmetry in the modelling of CFPs for low-symmetry cases which is essential for technological applications and engineering of rare-earth activated phosphor materials.
Collapse
Affiliation(s)
- Riti Ghosh
- Department of Physics, University of Kalyani, Kalyani-741235, Nadia, WB, India.
| | - Shankhanil Sarkar
- Department of Physics, University of Kalyani, Kalyani-741235, Nadia, WB, India.
| | - Yatramohan Jana
- Department of Physics, University of Kalyani, Kalyani-741235, Nadia, WB, India.
| | - Danuta Piwowarska
- Department of Technical Physics, Faculty of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology in Szczecin, 70-311 Szczecin, Poland
| | - Paweł Gnutek
- Laboratory for Research on Structure and Mechanical Properties of Materials POLITEST, Faculty of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology in Szczecin, 70-311 Szczecin, Poland
| | - Czesław Rudowicz
- Faculty of Chemistry, Adam Mickiewicz University, 61-614 Poznań, Poland.
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Xiong J, Liu Q, Lavina B, Hu MY, Zhao J, Alp EE, Deng L, Ye S, Guo Y. Spin polarization assisted facile C-H activation by an S = 1 iron(iv)-bisimido complex: a comprehensive spectroscopic and theoretical investigation. Chem Sci 2023; 14:2808-2820. [PMID: 36937578 PMCID: PMC10016330 DOI: 10.1039/d2sc06273a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/14/2023] [Indexed: 02/17/2023] Open
Abstract
High valent iron terminal imido species (Fe[double bond, length as m-dash]NR) have been shown to be key reactive intermediates in C-H functionalization. However, the detailed structure-reactivity relationship in Fe[double bond, length as m-dash]NR species derived from studies of structurally well-characterized high-valent Fe[double bond, length as m-dash]NR complexes are still scarce, and the impact of imido N-substituents (electron-donating vs. electron-withdrawing) on their electronic structures and reactivities has not been thoroughly explored. In this study, we report spectroscopic and computational studies on a rare S = 1 iron(iv)-bisimido complex featuring trifluoromethyl groups on the imido N-substituents, [(IPr)Fe(NC(CF3)2Ph)2] (2), and two closely related S = 0 congeners bearing alkyl and aryl substituents, [(IPr)Fe(NC(CMe3)2Ph)2] (3) and [(IPr)Fe(NDipp)2] (1), respectively. Compared with 1 and 3, 2 exhibits a decreased Fe[double bond, length as m-dash]NR bond covalency due to the electron-withdrawing and the steric effect of the N-substituents, which further leads to a pseudo doubly degenerate ground electronic structure and spin polarization induced β spin density on the imido nitrogens. This unique electronic structure, which differs from those of the well-studied Fe(iv)-oxido complexes and many previously reported Fe(iv)-imido complexes, provides both kinetic and thermodynamic advantages for facile C-H activation, compared to the S = 0 counterparts.
Collapse
Affiliation(s)
- Jin Xiong
- Department of Chemistry, Carnegie Mellon University Pittsburgh Pennsylvania 15213 USA
| | - Qing Liu
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 200032 P. R. China
| | - Barbara Lavina
- Advanced Photon Source, Argonne National Laboratory Argonne Illinois 60439 USA
- Center for Advanced Radiation Sources, University of Chicago Chicago Illinois 60439 USA
| | - Michael Y Hu
- Advanced Photon Source, Argonne National Laboratory Argonne Illinois 60439 USA
| | - Jiyong Zhao
- Advanced Photon Source, Argonne National Laboratory Argonne Illinois 60439 USA
| | - Esen E Alp
- Advanced Photon Source, Argonne National Laboratory Argonne Illinois 60439 USA
| | - Liang Deng
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 200032 P. R. China
| | - Shengfa Ye
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences Dalian 116023 P. R. China
| | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University Pittsburgh Pennsylvania 15213 USA
| |
Collapse
|
13
|
Biswas A, Sarkar S, Jana Y, Swarnakar D, Rudowicz C. Effects of distortions in ion-host systems on optical spectra, crystal-field and spin-Hamiltonian parameters of Cr 3+ ions doped pyrochlores Y 2Ti 2O 7 and Y 2Sn 2O 7: exchange charge model and superposition model calculations. Phys Chem Chem Phys 2023; 25:5082-5094. [PMID: 36723002 DOI: 10.1039/d2cp04350e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Comparative modelling of the crystal-field parameters (CFPs), CF energy levels, and effective spin-Hamiltonian parameters (SHPs), i.e., the g-factors and zero-field splitting parameter (ZFSP), D, of the ground state 4A2g of the Cr3+ dopant ions in Y2Ti2O7 and Y2Sn2O7 is carried out. The CFPs are calculated using XRD structural data by employing two semi-empirical models: the exchange charge model (ECM) and superposition model (SPM). This two-fold approach ensures increased reliability of CFP modelling and thus of the final results. The modelled CFPs serve as the input to the crystal-field analysis/microscopic spin-Hamiltonian (CFA/MSH) program to predict CF energy levels and wave functions, and to extract SHPs. Since the site symmetry of Cr3+ ions in these crystals is trigonal D3d, a symmetry adapted axis system (SAAS) conforming to Watanabe convention is adopted for CFP modelling. The calculated CF energies and SHPs for Y2Ti2O7:Cr3+ are in good agreement with the experimental results. Variations of the Racah parameter B, as well as ECM and SPM parameters for Y2Sn2-xCrxO7 are correlated with the chromium concentration (x), which affects distortions of CrO6 structures. We find that the SHPs originate predominantly from the spin-orbit coupling, though contributions from spin-spin and spin-other-orbit couplings are also appreciable and thus important for analysis of lattice distortions and structural disorder. The uniqueness of the SAAS used for CFP modelling is also discussed. The present study enables exploring the influence of the radial and angular distortions of host clusters (Ti-O6/Sn-O6) introduced by Cr3+ ions on the structural and optical properties as well as the SHPs of Cr3+ ions doped in Y2Ti2O7 and Y2Sn2O7.
Collapse
Affiliation(s)
- Anwesha Biswas
- Department of Physics, University of Kalyani, Kalyani-741235, Nadia, WB, India.
| | - Shankhanil Sarkar
- Department of Physics, University of Kalyani, Kalyani-741235, Nadia, WB, India.
| | - Yatramohan Jana
- Department of Physics, University of Kalyani, Kalyani-741235, Nadia, WB, India.
| | - Debasish Swarnakar
- Department of Physics, University of Kalyani, Kalyani-741235, Nadia, WB, India.
| | - Czesław Rudowicz
- Faculty of Chemistry, Adam Mickiewicz University, 61-614 Poznań, Poland
| |
Collapse
|
14
|
Münster K, Baabe D, Kintzel B, Böhme M, Plass W, Raeder J, Walter MD. Low-Coordinate Iron(II) Amido Half-Sandwich Complexes with Large Internal Magnetic Hyperfine Fields. Inorg Chem 2022; 61:18883-18898. [DOI: 10.1021/acs.inorgchem.2c02768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Katharina Münster
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, Braunschweig38106, Germany
| | - Dirk Baabe
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, Braunschweig38106, Germany
| | - Benjamin Kintzel
- Institut für Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstraße 8, Jena07743, Germany
| | - Michael Böhme
- Institut für Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstraße 8, Jena07743, Germany
| | - Winfried Plass
- Institut für Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstraße 8, Jena07743, Germany
| | - Jan Raeder
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, Braunschweig38106, Germany
| | - Marc D. Walter
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, Braunschweig38106, Germany
| |
Collapse
|
15
|
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.
Collapse
|
16
|
Khurana R, Ali ME. Single-Molecule Magnetism in Linear Fe(I) Complexes with Aufbau and Non-Aufbau Ground States. Inorg Chem 2022; 61:15335-15345. [PMID: 36129329 DOI: 10.1021/acs.inorgchem.2c00981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
With the ongoing efforts on synthesizing mononuclear single-ion magnets (SIMs) with promising applications in high-density data storage and spintronics devices, the linear or quasi-linear Fe(I) complexes emerge as the enticing candidates possessing large unquenched angular momentum. Herein, we have studied five experimentally synthesized linear Fe(I) complexes to uncover the origin of single-molecule magnetic behavior of these complexes. To begin with, we benchmarked the methodology on the experimentally and theoretically well-studied complex [Fe(C(SiMe3)3)2]-1 (1) (SiMe3 = trimethylsilyl), which is characterized with a large spin-reversal barrier of 226 cm-1. Subsequently, the spin-phonon coupling coefficients are calculated for the low-frequency vibrational modes to understand the relaxation mechanism of the complex. Furthermore, the two Fe(I) complexes, that is, [Fe(cyIDep)2]+1 (2) (cyIDep = 1,3-bis(2',6'-diethylphenyl)-4,5-(CH2)4-imidazole-2-ylidene) and [Fe(sIDep)2]+1 (3) (sIDep = 1,3-bis(2',6'-diethylphenyl)-imidazolin-2-ylidene), are studied that are experimentally reported with no SIM behavior under ac or dc magnetic fields; however, they exhibit large opposite axial zero field splitting (-62.4 and +34.0 cm-1, respectively) from ab initio calculations. We have unwrapped the origin of this contrasting observation between experiment and theory by probing their magnetic relaxation pathways and the pattern of d orbital splitting. Additionally, the two experimentally synthesized Fe(I) complexes, that is, [(η6-C6H6)FeAr*-3,5-Pr2i] (4) (Ar*-3,5-Pr2i = C6H-2,6-(C6H2-2,4,6-Pr3i)2-3,5-Pr2i) and [(CAAC)2Fe]+1 (5) (CAAC = cyclic (alkyl) (amino)carbene), are investigated for SIM behavior, since there is no report on their magnetic anisotropy. To this end, complex 4 presents itself as the possible candidate for SIM.
Collapse
Affiliation(s)
- Rishu Khurana
- 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
| |
Collapse
|
17
|
Nain S, Khurana R, Ali ME. Harnessing Colossal Magnetic Anisotropy in Sandwiched 3d 2-Metallocenes. J Phys Chem A 2022; 126:2811-2817. [PMID: 35507013 DOI: 10.1021/acs.jpca.2c01605] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Single-molecule magnets are gaining attention in recent years with the growing focus on achieving higher barriers of magnetization reversal. Metallocenes, owing to their unique sandwiched structure, assure themselves as plausible molecular systems for the development of novel single-molecule magnets (SMMs). Here in this work, we have explicitly investigated metallocenes of first-row transition elements, along with their one-electron-oxidized (cationic) and -reduced (anionic) analogues, for their magnetic anisotropies by adopting multireference ab initio calculations. Herein, we report a high magnetic anisotropy for 3d2 systems among all 3d-metallocenes.
Collapse
Affiliation(s)
- Sakshi Nain
- Institute of Nano Science and Technology, Sector-81, Mohali 140306, Punjab, India
| | - Rishu Khurana
- Institute of Nano Science and Technology, Sector-81, Mohali 140306, Punjab, India
| | - Md Ehesan Ali
- Institute of Nano Science and Technology, Sector-81, Mohali 140306, Punjab, India
| |
Collapse
|
18
|
Campanella AJ, Ozvat TM, Zadrozny JM. Ligand design of zero-field splitting in trigonal prismatic Ni(II) cage complexes. Dalton Trans 2022; 51:3341-3348. [PMID: 35137732 PMCID: PMC8992015 DOI: 10.1039/d1dt02156g] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Complexes of encapsulated metal ions are promising potential metal-based electron paramagnetic resonance imaging (EPRI) agents due to zero-field splitting. Herein, we synthesize and magnetically characterize a series of five new Ni(II) complexes based on a clathrochelate ligand to provide a new design strategy for zero-field splitting in an encaged environment. UV-Vis and X-ray single-crystal diffraction experiments demonstrate slight physical and electronic structure changes as a function of the differing substituents. The consequence of these changes at the remote apical and sidearm positions of the encaging ligands is a zero-field splitting parameter (D) that varies over a large range of 11 cm-1. These results demonstrate a remarkable flexibility of the zero-field splitting and electronic structure in nickelous cages and give a clear toolkit for modifying zero-field splitting in highly stable ligand shells.
Collapse
Affiliation(s)
| | - Tyler M. Ozvat
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA
| | - Joseph M. Zadrozny
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA
| |
Collapse
|
19
|
Dais TN, Takano R, Ishida T, Plieger PG. Self-assembly of non-macrocyclic triangular Ni 3Ln clusters. Dalton Trans 2022; 51:1446-1453. [PMID: 34985086 DOI: 10.1039/d1dt03742k] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis and structural characterisation of four new heterometallic tetranuclear complexes is reported. Three L3Ni3Ln type complexes, where Ln = La (C1), Eu (C2), and Gd (C3), have been fully characterised including DC and AC magnetic measurements. A fourth complex featuring a diamagnetic BaII ion at its centre is also reported with structural characterisation. Structural elucidation showed that all four complexes successfully self-assembled from a stoichiometric mixture of the acyclic ligand, 1,4-diformylnaphthalene-2,3-diol, with nickel(II) nitrate and the appropriate heavy metal salt to produce the same near planar Ni3MO12 core. Ferromagnetic interactions were found to dominate the ground state of C3, exhibiting a maximal spin ground state of 13/2. The exchange coupling is quantitatively discussed along with the nickel(II) zero-field splitting effect. AC magnetic susceptibility experiments were carried out, but no frequency dependent signals were observed and thus no observable slow relaxation of magnetisation.
Collapse
Affiliation(s)
- Tyson N Dais
- School of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand.
| | - Rina Takano
- Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan
| | - Takayuki Ishida
- Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan
| | - Paul G Plieger
- School of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand.
| |
Collapse
|
20
|
Blackaby WJM, Harriman KLM, Greer SM, Folli A, Hill S, Krewald V, Mahon MF, Murphy DM, Murugesu M, Richards E, Suturina E, Whittlesey MK. Extreme g-Tensor Anisotropy and Its Insensitivity to Structural Distortions in a Family of Linear Two-Coordinate Ni(I) Bis-N-heterocyclic Carbene Complexes. Inorg Chem 2022; 61:1308-1315. [PMID: 35005902 DOI: 10.1021/acs.inorgchem.1c02413] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report a new series of homoleptic Ni(I) bis-N-heterocyclic carbene complexes with a range of torsion angles between the two ligands from 68° to 90°. Electron paramagnetic resonance measurements revealed a strongly anisotropic g-tensor in all complexes with a small variation in g∥ ∼ 5.7-5.9 and g⊥ ∼ 0.6. The energy of the first excited state identified by variable-field far-infrared magnetic spectroscopy and SOC-CASSCF/NEVPT2 calculations is in the range 270-650 cm-1. Magnetic relaxation measured by alternating current susceptibility up to 10 K is dominated by Raman and direct processes. Ab initio ligand-field analysis reveals that a torsion angle of <90° causes the splitting between doubly occupied dxz and dyz orbitals, which has little effect on the magnetic properties, while the temperature dependence of the magnetic relaxation appears to have no correlation with the torsion angle.
Collapse
Affiliation(s)
| | - Katie L M Harriman
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5, Canada
| | - Samuel M Greer
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States.,Department of Chemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Andrea Folli
- School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, U.K
| | - Stephen Hill
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States.,Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Vera Krewald
- Theoretical Chemistry, TU Darmstadt, Alarich-Weiss-Strasse 4, 64287 Darmstadt, Germany
| | - Mary F Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Damien M Murphy
- School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, U.K
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5, Canada
| | - Emma Richards
- School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, U.K
| | - Elizaveta Suturina
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | | |
Collapse
|
21
|
Otlyotov A, Moshchenkov A, Cavallo L, Minenkov Y. 16OSTM10: A new open-shell transition metal conformational energies database to challenge contemporary semiempirical and force field methods. Phys Chem Chem Phys 2022; 24:17314-17322. [DOI: 10.1039/d2cp01659a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
transition metal (OSTM) complexes has been developed. Contemporary composite density functional theory (DFT) (PBEh-3c, B97-3c), semiempirical (PM6, PM7) and the methods of GFNn-xTB/FF family were examined against conventional DFT (PBE-D3(BJ),...
Collapse
|
22
|
Li Y, Xi J, Ferrando-Soria J, Zhang YQ, Wang W, Song Y, Guo Y, Pardo E, Liu X. Slow magnetic relaxation in a trigonal-planar mononuclear Fe(II) complex. Dalton Trans 2022; 51:8266-8272. [DOI: 10.1039/d2dt00899h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Based on a β-diketiminate ligand, an iron(III) tetrahedral high-spin complex, [LFeIII(Cl)2] (1), and an iron(II) high-spin triangular planar complex, [LFeIICl] (2), have been synthesized and structurally characterized. Also, complex 1...
Collapse
|
23
|
Indris S, Bredow T, Schwarz B, Eichhöfer A. Paramagnetic 7Li NMR Shifts and Magnetic Properties of Divalent Transition Metal Silylamide Ate Complexes [LiM{N(SiMe 3) 2} 3] (M 2+ = Mn, Fe, Co). Inorg Chem 2021; 61:554-567. [PMID: 34931842 DOI: 10.1021/acs.inorgchem.1c03237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
7Li NMR shifts and magnetic properties have been determined for three so-called ate complexes [LiM{N(SiMe3)2}3] (M2+ = Mn, Fe, Co; e.g., named lithium-tris(bis(trimethylsilylamide))-manganate(II) in accordance with a formally negative charge assigned to the complex fragment [M{N(SiMe3)2}3]-, which comprises the transition metal). They are formed by addition reactions of LiN(SiMe3)2 and [M{N(SiMe3)2}2] and stabilized by Lewis base/Lewis acid interactions. The results are compared to those of the related "ion-separated" complexes [Li(15-crown-5)][M{N(SiMe3)2}3]. The ate complexes with the lithium atoms connected to the 3d metal atoms manganese, iron, or cobalt via μ2 nitrogen bridges reveal strong 7Li NMR paramagnetic shifts of about -75, 125, and 171 ppm, respectively, whereas the shifts for the lithium ions coordinated by the 15-crown-5 ether are close to zero. The observed trends of the 7Li NMR shifts are confirmed by density-functional theory calculations. The magnetic dc and ac properties display distinct differences for the six compounds under investigation. Both manganese compounds, [LiMn{N(SiMe3)2}3] and [Li(15-crown-5)][Mn{N(SiMe3)2}3], display almost pure and ideal spin-only paramagnetic behavior of a 3d5 high-spin complex. In this respect slightly unexpected, both complexes show slow relaxation behavior at low temperatures under applied dc fields, which is especially pronounced for the ate complex [LiMn{N(SiMe3)2}3]. Dc magnetic properties of the iron complexes reveal moderate g-factor anisotropies with small values of the axial magnetic anisotropy parameter D and a larger E (transversal anisotropy). Both complexes display at low temperatures and, under external dc fields of up to 5000 Oe, only weak ac signals with no maxima in the frequency range from 1 to 1500 s-1. In contrast, the two cobalt complexes display strong g-factor anisotropies with large values of D and E. In addition, in both cases, the ac measurements at low temperatures and applied dc fields reveal two, in terms of their frequency range, well separated relaxation processes with maxima lying for the most part outside of the measurement range between 1 and 1500 s-1.
Collapse
Affiliation(s)
- Sylvio Indris
- Institute for Applied Materials - Energy Storage Systems (IAM-ESS), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Thomas Bredow
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Universität Bonn, Beringstraße 4, 53115 Bonn, Germany
| | - Björn Schwarz
- Institute for Applied Materials - Energy Storage Systems (IAM-ESS), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Andreas Eichhöfer
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Campus Nord, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.,Karlsruhe Nano Micro Facility (KNMF), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| |
Collapse
|
24
|
Chakarawet K, Atanasov M, Ellis JE, Lukens WW, Young VG, Chatterjee R, Neese F, Long JR. Effect of Spin-Orbit Coupling on Phonon-Mediated Magnetic Relaxation in a Series of Zero-Valent Vanadium, Niobium, and Tantalum Isocyanide Complexes. Inorg Chem 2021; 60:18553-18560. [PMID: 34807605 DOI: 10.1021/acs.inorgchem.1c03173] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Spin-vibronic coupling leads to spin relaxation in paramagnetic molecules, and an understanding of factors that contribute to this phenomenon is essential for designing next-generation spintronics technology, including single-molecule magnets and spin-based qubits, wherein long-lifetime magnetic ground states are desired. We report spectroscopic and magnetic characterization of the isoelectronic and isostructural series of homoleptic zerovalent transition metal triad M(CNDipp)6 (M = V, Nb, Ta; CNDipp = 2,6-diisopropylphenyl isocyanide) and show experimentally the significant increase in spin relaxation rate upon going from V to Nb to Ta. Correlated electronic calculations and first principle spin-phonon computations support the role of spin-orbit coupling in modulating spin-phonon relaxation. Our results provide experimental evidence that increasing magnetic anisotropy through spin-orbit coupling interactions leads to increased spin-vibronic relaxation, which is detrimental to long spin lifetime in paramagnetic molecules.
Collapse
Affiliation(s)
- Khetpakorn Chakarawet
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Mihail Atanasov
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Science, Akad. G. Bontchev Street, Bl.11, 1113 Sofia, Bulgaria.,Max-Planck Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - John E Ellis
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Wayne W Lukens
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Victor G Young
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Ruchira Chatterjee
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Frank Neese
- Max-Planck Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Jeffrey R Long
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States.,Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| |
Collapse
|
25
|
Legendre CM, Lüert D, Herbst-Irmer R, Stalke D. Benchmarking magnetic and spectroscopic properties on highly stable 3d metal complexes with tuneable bis(benzoxazol-2-yl)methanide ligands. Dalton Trans 2021; 50:16810-16818. [PMID: 34766963 DOI: 10.1039/d1dt03230e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two series a and b of 3d metal based complexes 1-4 [MII{(4-R-NCOC6H4)2CH}2], (with M = Mn (1), Fe (2), Co (3), Ni (4) and R = H (a) or Me (b)) were synthesised and structurally characterized. The complexes were found to crystallize differently depending on the dication ionic radius and the ligand substitution. All complexes showed remarkable X-ray diffraction resolution that will allow further advanced diffraction experiments. Subsequently, their spectroscopic and magnetic properties were analysed. Complexes 3a and 3b notably show slow magnetic relaxation of their magnetization and represent simple model systems relaxing through a phonon-bottleneck process (3a) or as a field-induced single-molecule magnet (3b, Ueff = 45.0 cm-1). Remarkably, the magnetic anisotropy in the manganese complex 1b results in induced slow magnetic relaxation. The influence of the dual 4-methylation of the ligands was investigated and found to generate important variations in the physical features of the corresponding complexes. Accessible via one-pot synthesis, these are highly robust against oxidation and moisture. Through smart ligand engineering, they represent stable and tuneable compounds for benchmarking purposes through standard and less-standard characterization methods.
Collapse
Affiliation(s)
- Christina M Legendre
- Institute for Inorganic Chemistry, University of Göttingen, Tammannstrasse 4, 37077 Göttingen, Germany.
| | - Daniel Lüert
- Institute for Inorganic Chemistry, University of Göttingen, Tammannstrasse 4, 37077 Göttingen, Germany.
| | - Regine Herbst-Irmer
- Institute for Inorganic Chemistry, University of Göttingen, Tammannstrasse 4, 37077 Göttingen, Germany.
| | - Dietmar Stalke
- Institute for Inorganic Chemistry, University of Göttingen, Tammannstrasse 4, 37077 Göttingen, Germany.
| |
Collapse
|
26
|
Walleck S, Atanasov M, Schnack J, Bill E, Stammler A, Bögge H, Glaser T. Rational Design of a Confacial Pentaoctahedron: Anisotropic Exchange in a Linear Zn II Fe III Fe III Fe III Zn II Complex. Chemistry 2021; 27:15239-15250. [PMID: 34427372 PMCID: PMC8596665 DOI: 10.1002/chem.202102572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Indexed: 11/10/2022]
Abstract
The first confacial pentaoctahedron comprised of transition metal ions namely ZnII FeIII A FeIII B FeIII A ZnII has been synthesized by using a dinucleating nonadentate ligand. The face-sharing bridging mode enforces short ZnII ⋅⋅⋅FeIII A and FeIII A ⋅⋅⋅FeIII B distances of 2.83 and 2.72 Å, respectively. Ab-initio CASSCF/NEVPT2 calculations provide significant negative zero-field splittings for FeIII A and FeIII B with |DA |>|DB | with the main component along the C3 axis. Hence, a spin-Hamiltonian comprised of anisotropic exchange, zero-field, and Zeeman term was employed. This allowed by following the boundary conditions from the theoretical results the simulation in a theory-guided parameter determination with Jxy =+0.37, Jz =-0.32, DA =-1.21, EA =-0.24, DB =-0.35, and EB =-0.01 cm-1 supported by simulations of high-field magnetic Mössbauer spectra recorded at 2 K. The weak but ferromagnetic FeIII A FeIII B interaction arises from the small bridging angle of 84.8° being at the switch from anti- to ferromagnetic for the face-sharing bridging mode.
Collapse
Affiliation(s)
- Stephan Walleck
- Lehtuhl für Anorganische Chemie IFakultät für ChemieUniversität BielefeldUniversitätsstr. 2533615BielefeldGermany
| | - Mihail Atanasov
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
- Institute of General and Inorganic ChemistryBulgarian Academy of SciencesAkad. G. Bontchev Street, Bl.111113SofiaBulgaria
| | - Jürgen Schnack
- Fakultät für PhysikUniversität BielefeldPostfach 10013133501BielefeldGermany
| | - Eckhard Bill
- Max-Planck-Institut für Chemische EnergiekonversionStiftstr. 34–3645470Mülheim an der RuhrGermany
| | - Anja Stammler
- Lehtuhl für Anorganische Chemie IFakultät für ChemieUniversität BielefeldUniversitätsstr. 2533615BielefeldGermany
| | - Hartmut Bögge
- Lehtuhl für Anorganische Chemie IFakultät für ChemieUniversität BielefeldUniversitätsstr. 2533615BielefeldGermany
| | - Thorsten Glaser
- Lehtuhl für Anorganische Chemie IFakultät für ChemieUniversität BielefeldUniversitätsstr. 2533615BielefeldGermany
| |
Collapse
|
27
|
Novikov VV, Nelyubina YV. Modern physical methods for the molecular design of single-molecule magnets. RUSSIAN CHEMICAL REVIEWS 2021. [DOI: 10.1070/rcr5002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Abstract
Many paramagnetic metal complexes have emerged as unique magnetic materials (single-molecule magnets), which behave as conventional magnets at the single-molecule level, thereby making it possible to use them in modern devices for data storage and processing. The rational design of these complexes, however, requires a deep understanding of the physical laws behind a single-molecule magnet behaviour, the mechanisms of magnetic relaxation that determines the magnetic properties and the relationship of these properties with the structure of single-molecule magnets. This review focuses on the physical methods providing such understanding, including different versions and various combinations of magnetometry, electron paramagnetic and nuclear magnetic resonance spectroscopy, optical spectroscopy and X-ray diffraction. Many of these methods are traditionally used to determine the composition and structure of new chemical compounds. However, they are rarely applied to study molecular magnetism.
The bibliography includes 224 references.
Collapse
|
28
|
Legendre CM, Herbst-Irmer R, Stalke D. Enhancing Steric Hindrance via Ligand Design in Dysprosium Complexes: From Induced Slow Relaxation to Zero-Field Single-Molecule Magnet Properties. Inorg Chem 2021; 60:13982-13989. [PMID: 34450008 DOI: 10.1021/acs.inorgchem.1c00973] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis and magnetic characterization of three novel Dy compounds, [Dy{PPh2S(NtBu)2}2(μ-Cl2)Li(THF)2] (1), [Dy{PhS(NtBu)2}2(μ-Cl2)Li(THF)2] (2), and [Dy{MeS(NtBu)3}2(μ-Cl2)Li(THF)2] (3), based on the sulfur-nitrogen ligands RS(NtBu)x- (where R = PPh2, x = 2 for (1); R = Ph, x = 2 for (2); and R = Me, x = 3 for (3)) are reported. They represent rare examples of lanthanide-based complexes containing sulfur-nitrogen ligands, whose suitability to enhance the magnetic anisotropy in 3d metals was only recently established. Changes in the ligand field environment drastically affect the magnetic properties, with compounds 1 and 2 displaying field-induced single-molecule magnet (SMM) behavior, while compound 3 shows slow relaxation at zero field. These trends strongly suggest that ligand engineering strategies toward linear dysprosium complexes, similar to those for dysprosocenium complexes, should enhance the SMM performances of SN-based lanthanide compounds.
Collapse
Affiliation(s)
- Christina M Legendre
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraße 4, 37077 Göttingen, Germany
| | - Regine Herbst-Irmer
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraße 4, 37077 Göttingen, Germany
| | - Dietmar Stalke
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstraße 4, 37077 Göttingen, Germany
| |
Collapse
|
29
|
Klahn EA, Damgaard-Møller E, Krause L, Kibalin I, Gukasov A, Tripathi S, Swain A, Shanmugam M, Overgaard J. Quantifying magnetic anisotropy using X-ray and neutron diffraction. IUCRJ 2021; 8:833-841. [PMID: 34584744 PMCID: PMC8420765 DOI: 10.1107/s2052252521008290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
In this work, the magnetic anisotropy in two iso-structural distorted tetrahedral Co(II) complexes, CoX 2tmtu2 [X = Cl(1) and Br(2), tmtu = tetra-methyl-thio-urea] is investigated, using a combination of polarized neutron diffraction (PND), very low-temperature high-resolution synchrotron X-ray diffraction and CASSCF/NEVPT2 ab initio calculations. Here, it was found consistently among all methods that the compounds have an easy axis of magnetization pointing nearly along the bis-ector of the compression angle, with minute deviations between PND and theory. Importantly, this work represents the first derivation of the atomic susceptibility tensor based on powder PND for a single-molecule magnet and the comparison thereof with ab initio calculations and high-resolution X-ray diffraction. Theoretical ab initio ligand field theory (AILFT) analysis finds the d xy orbital to be stabilized relative to the d xz and d yz orbitals, thus providing the intuitive explanation for the presence of a negative zero-field splitting parameter, D, from coupling and thus mixing of d xy and . Experimental d-orbital populations support this interpretation, showing in addition that the metal-ligand covalency is larger for Br-ligated 2 than for Cl-ligated 1.
Collapse
Affiliation(s)
- Emil Andreasen Klahn
- Department of Chemistry, Aarhus University, Langelandsgade 140, Aarhus C 8000, Denmark
| | - Emil Damgaard-Møller
- Department of Chemistry, Aarhus University, Langelandsgade 140, Aarhus C 8000, Denmark
| | - Lennard Krause
- Department of Chemistry, Aarhus University, Langelandsgade 140, Aarhus C 8000, Denmark
| | - Iurii Kibalin
- LLB, CEA, CE de Saclay, Gif sur Yvette 91191, France
| | - Arsen Gukasov
- LLB, CEA, CE de Saclay, Gif sur Yvette 91191, France
| | - Shalini Tripathi
- Department of Chemistry, IIT Bombay, Powai, Mumbai, Maharashtra 400076, India
| | - Abinash Swain
- Department of Chemistry, IIT Bombay, Powai, Mumbai, Maharashtra 400076, India
| | | | - Jacob Overgaard
- Department of Chemistry, Aarhus University, Langelandsgade 140, Aarhus C 8000, Denmark
| |
Collapse
|
30
|
|
31
|
The angular overlap model of ligand field theory for f elements: An intuitive approach building bridges between theory and experiment. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.213981] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
|
32
|
Weller R, Ruppach L, Shlyaykher A, Tambornino F, Werncke CG. Homoleptic quasilinear metal(i/ii) silylamides of Cr-Co with phenyl and allyl functions - impact of the oxidation state on secondary ligand interactions. Dalton Trans 2021; 50:10947-10963. [PMID: 34318833 DOI: 10.1039/d1dt01543e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Herein we describe the synthesis and characterization of a variety of new quasilinear metal(i/ii) silylamides of the type [M(N(Dipp)SiR3)2]0,- (M = Cr-Co) with different silyl substituents (SiR3 = SiPh3-nMen (n = 1-3), SiMe2(allyl)). By comparison of the solid state structures we show that in the case of phenyl substituents secondary metal-ligand interactions are suppressed upon reduction of the metal. Introduction of an allyl substituted silylamide gives divalent complexes with additional metal-π-alkene interactions with only weak activation of the C[double bond, length as m-dash]C bond but substantial bending of the principal N-M-N axis. 1e--reduction makes cobalt a more strongly bound alkene substituent, whereas for chromium, reduction and intermolecular dimerisation of the allyl unit are observed. It thus indicates that the general view of low-coordinate 3d-metal ions as electron deficient seems not to apply to anionic metal(i) complexes. Additionally, the obtained cobalt(i) complexes are reacted with an aryl azide giving trigonal imido metal complexes. These can be regarded as rare examples of high-spin imido cobalt compounds from their structural and solution magnetic features.
Collapse
Affiliation(s)
- Ruth Weller
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.
| | - Lutz Ruppach
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.
| | - Alena Shlyaykher
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.
| | - Frank Tambornino
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.
| | - C Gunnar Werncke
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.
| |
Collapse
|
33
|
Alessio M, Krylov AI. Equation-of-Motion Coupled-Cluster Protocol for Calculating Magnetic Properties: Theory and Applications to Single-Molecule Magnets. J Chem Theory Comput 2021; 17:4225-4241. [PMID: 34191507 DOI: 10.1021/acs.jctc.1c00430] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We present a new computational protocol for computing macroscopic magnetic properties of transition-metal complexes using the equation-of-motion coupled-cluster (EOM-CC) framework. The approach follows a two-step state-interaction scheme: we first compute zero-order states using nonrelativistic EOM-CC and then use these states to evaluate matrix elements of the spin-orbit and Zeeman operators. Diagonalization of the resulting Hamiltonian yields spin-orbit- and field-perturbed eigenstates. Temperature- and field-dependent magnetization and susceptibility are computed by numerical differentiation of the partition function. To compare with powder-sample experiments, these quantities are numerically averaged over field orientations. We applied this protocol to several single-molecule magnets (SMMs) with Fe(II) and Fe(III) in trigonal pyramidal, linear, and trigonal bipyramidal coordination environments. We described the underlying electronic structure by the electron-attachment (EOM-EA) and spin-flip (EOM-SF) variants of EOM-CC. The computed energy barriers for spin inversion, and macroscopic magnetization and susceptibility agree well with experimental data. Trends in magnetic anisotropy and spin-reversal energy barriers are explained in terms of a molecular orbital picture rigorously distilled from spinless transition density matrices between many-body states. The results illustrate excellent performances of EOM-CC in describing magnetic behavior of mononuclear transition-metal SMMs.
Collapse
Affiliation(s)
- Maristella Alessio
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| | - Anna I Krylov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| |
Collapse
|
34
|
Tiaouinine S, Flores Gonzalez J, Lefeuvre B, Guizouarn T, Cordier M, Dorcet V, Kaboub L, Cador O, Pointillart F. Spin Crossover and Field‐Induced Single‐Molecule Magnet Behaviour in Co(II) Complexes Based on Terpyridine with Tetrathiafulvalene Analogues. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100247] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Siham Tiaouinine
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
- Laboratory of Organic Materials and Heterochemistry University of Tebessa Rue de Constantine 12002 Tébessa Algeria
| | - Jessica Flores Gonzalez
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
| | - Bertrand Lefeuvre
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
| | - Thierry Guizouarn
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
| | - Marie Cordier
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
| | - Vincent Dorcet
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226 35000 Rennes France
| | - Lakehmici Kaboub
- Laboratory of Organic Materials and Heterochemistry University of Tebessa Rue de Constantine 12002 Tébessa Algeria
- Laboratory of Chemistry Molecular Engineering and Nanostructures University of Ferhat Abbas-Sétif 1 19000 Sétif Algeria
| | - Olivier Cador
- 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
| |
Collapse
|
35
|
Legendre CM, Damgaard‐Møller E, Overgaard J, Stalke D. The Quest for Optimal 3 d Orbital Splitting in Tetrahedral Cobalt Single‐Molecule Magnets Featuring Colossal Anisotropy and Hysteresis. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100465] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Christina M. Legendre
- Institut für Anorganische Chemie Georg-August-Universität Göttingen Tammannstraβe 4 37077 Göttingen Germany
| | - Emil Damgaard‐Møller
- Department of Chemistry Aarhus University Langelandsgade 140 Aarhus C 8000 Denmark
| | - Jacob Overgaard
- Department of Chemistry Aarhus University Langelandsgade 140 Aarhus C 8000 Denmark
| | - Dietmar Stalke
- Institut für Anorganische Chemie Georg-August-Universität Göttingen Tammannstraβe 4 37077 Göttingen Germany
| |
Collapse
|
36
|
Generation of a Hetero Spin Complex from Iron(II) Iodide with Redox Active Acenaphthene-1,2-Diimine. Molecules 2021; 26:molecules26102998. [PMID: 34070061 PMCID: PMC8158106 DOI: 10.3390/molecules26102998] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/12/2021] [Accepted: 05/14/2021] [Indexed: 11/16/2022] Open
Abstract
The reaction of the redox active 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-BIAN) and iron(II) iodide in acetonitrile led to a new complex [(dpp-BIAN)FeIII2] (1). Molecular structure of 1 was determined by the single crystal X-ray diffraction analysis. The spin state of the iron cation in complex 1 at room temperature and the magnetic behavior of 1 in the temperature range of 2–300 K were studied using Mossbauer spectroscopy and magnetic susceptibility measurements, respectively. The neutral character of dpp-BIAN in 1 was confirmed by IR and UV spectroscopy. The electrochemistry of 1 was studied in solution and solid state using cyclic voltammetry. The generation of the radical anion form of the dpp-BIAN ligand upon reduction of 1 in a CH2Cl2 solution was monitored by EPR spectroscopy.
Collapse
|
37
|
Water-oriented magnetic anisotropy transition. Nat Commun 2021; 12:2738. [PMID: 33980833 PMCID: PMC8115317 DOI: 10.1038/s41467-021-23057-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 04/14/2021] [Indexed: 12/04/2022] Open
Abstract
Water reorientation is essential in a wide range of chemical and biological processes. However, the effects of such reorientation through rotation around the metal–oxygen bond on the chemical and physical properties of the resulting complex are usually ignored. Most studies focus on the donor property of water as a recognized σ donor-type ligand rather than a participant in the π interaction. Although a theoretical approach to study water-rotation effects on the functionality of a complex has recently been conducted, it has not been experimentally demonstrated. In this study, we determine that the magnetic anisotropy of a Co(II) complex can be effectively controlled by the slight rotation of coordinating water ligands, which is achieved by a two-step structural phase transition. When the water molecule is rotated by 21.2 ± 0.2° around the Co–O bond, the directional magnetic susceptibility of the single crystal changes by approximately 30% along the a-axis due to the rotation of the magnetic anisotropy axis through the modification of the π interaction between cobalt(II) and the water ligand. The theoretical calculations further support the hypothesis that the reorientation of water molecules is a key factor contributing to the magnetic anisotropy transition of this complex. Little is known about how the orientation of coordinated water molecules affects the magnetic properties of single molecule magnets. Here the authors combine experimental data and theoretical calculations to study how the rotation of water molecules alters the magnetic anisotropy of a pyrazine-based cobalt(II) complex.
Collapse
|
38
|
Weller R, Müller I, Duhayon C, Sabo-Etienne S, Bontemps S, Werncke CG. Quasilinear 3d-metal(i) complexes [KM(N(Dipp)SiR 3) 2] (M = Cr-Co) - structural diversity, solution state behaviour and reactivity. Dalton Trans 2021; 50:4890-4903. [PMID: 33877186 DOI: 10.1039/d1dt00121c] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The synthesis and characterization of neutral quasilinear 3d-metal(i) complexes of chromium to cobalt of the type [KM(N(Dipp)SiMe3)2] (Dipp = 2,6-di-iso-propylphenyl) are reported. In solid state these metal(i) complexes either occur as isolated molecules (Co) or are part of a potassium ion linked 1D-coordination polymer (Cr-Fe). In solution the potassium cation is either ligated within the ligand sphere of the metal silylamide or is separated from the complex depending on the solvent. For iron, we showcase that it is possible to use sodium or lithium metal for the reduction of the metal(ii) precursor. However, in these cases the resulting iron(i) complexes can only be isolated upon cation separation using an appropriate crown-ether. Further, the neutral metal(i) complexes are used to introduce NBu4+ as an organic cation in the case of cobalt and iron. The impact of the intramolecular cation complexation was further demonstrated upon reaction with diphenyl acetylene which leads to bond formation processes and redox disproportionation instead of η2-alkyne complex formation.
Collapse
Affiliation(s)
- Ruth Weller
- Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.
| | | | | | | | | | | |
Collapse
|
39
|
Kuzmann E, Homonnay Z, Klencsár Z, Szalay R. 57Fe Mössbauer Spectroscopy as a Tool for Study of Spin States and Magnetic Interactions in Inorganic Chemistry. Molecules 2021; 26:molecules26041062. [PMID: 33670484 PMCID: PMC7922376 DOI: 10.3390/molecules26041062] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/12/2021] [Accepted: 02/15/2021] [Indexed: 11/16/2022] Open
Abstract
In this mini-review of our research group's activity, the application of 57Fe Mössbauer spectroscopy in studies of electronic structure, coordination environment, and magnetic interactions in an interesting series of Fe(II/III) compounds selected is discussed. We selected two prominent phenomena that arose during investigations of selected groups of compounds carried out at different periods of time: (1) very high magnetic hyperfine fields observed at low temperatures; (2) changes in the oxidation state of the central iron atom of complexes in the solid state during interactions with gaseous O2/H2O mixtures, resulting in spin crossover (SCO).
Collapse
Affiliation(s)
- Ernő Kuzmann
- Laboratory of Nuclear Chemistry, Institute of Chemistry, Eötvös Loránd University, 1117 Budapest, Hungary; (Z.H.); (Z.K.); (R.S.)
- Correspondence:
| | - Zoltán Homonnay
- Laboratory of Nuclear Chemistry, Institute of Chemistry, Eötvös Loránd University, 1117 Budapest, Hungary; (Z.H.); (Z.K.); (R.S.)
| | - Zoltán Klencsár
- Laboratory of Nuclear Chemistry, Institute of Chemistry, Eötvös Loránd University, 1117 Budapest, Hungary; (Z.H.); (Z.K.); (R.S.)
- Center for Energy Research, 1121 Budapest, Hungary
| | - Roland Szalay
- Laboratory of Nuclear Chemistry, Institute of Chemistry, Eötvös Loránd University, 1117 Budapest, Hungary; (Z.H.); (Z.K.); (R.S.)
| |
Collapse
|
40
|
Świtlicka A, Machura B, Cano J, Lloret F, Julve M. A Study of the Lack of Slow Magnetic Relaxation in Mononuclear Trigonal Bipyramidal Cobalt(II) Complexes. ChemistrySelect 2021. [DOI: 10.1002/slct.202100061] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Anna Świtlicka
- Department Of Crystallography, Institute of Chemistry University of Silesia 9th Szkolna St., 40–006 Katowice Poland
| | - Barbara Machura
- Department Of Crystallography, Institute of Chemistry University of Silesia 9th Szkolna St., 40–006 Katowice Poland
| | - Joan Cano
- Department of Química Inorgànica/Instituto de Ciencia Molecular (ICMol) Facultat de Quimica de la Universitat de València C/ Catedrático Jose Beltrán 2 46980 Paterna, València Spain
| | - Francesc Lloret
- Department of Química Inorgànica/Instituto de Ciencia Molecular (ICMol) Facultat de Quimica de la Universitat de València C/ Catedrático Jose Beltrán 2 46980 Paterna, València Spain
| | - Miguel Julve
- Department of Química Inorgànica/Instituto de Ciencia Molecular (ICMol) Facultat de Quimica de la Universitat de València C/ Catedrático Jose Beltrán 2 46980 Paterna, València Spain
| |
Collapse
|
41
|
Errulat D, Harriman KLM, Gálico DA, Ovens JS, Mansikkamäki A, Murugesu M. Aufbau vs. non-Aufbau ground states in two-coordinate d7 single-molecule magnets. Inorg Chem Front 2021. [DOI: 10.1039/d1qi00912e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Magnetic anisotropy is generated in two related d7 single-molecule magnets; (1) via 3d-4s orbital mixing in FeI; and (2) a non-Aufbau ground state in CoII, demonstrating that the electronic configurations are large retained independent of geometry.
Collapse
Affiliation(s)
- Dylan Errulat
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Katie L. M. Harriman
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Diogo A. Gálico
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Jeffrey S. Ovens
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Akseli Mansikkamäki
- A. Mansikkamäki, NMR Research Unit, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| |
Collapse
|
42
|
Meng X, Wang M, Gou X, Lan W, Jia K, Wang YX, Zhang YQ, Shi W, Cheng P. Two C2v symmetry dysprosium(iii) single-molecule magnets with effective energy barriers over 600 K. Inorg Chem Front 2021. [DOI: 10.1039/d1qi00145k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Two high-performance C2v symmetry dysprosium(iii) single-molecule magnets were synthesized. The mechanism of magnetization dynamics was studied in detail.
Collapse
Affiliation(s)
- Xixi Meng
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Mengmeng Wang
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Xiaoshuang Gou
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Wenlong Lan
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Kexin Jia
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Yu-Xia Wang
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Yi-Quan Zhang
- Jiangsu Key Lab for NSLSCS
- School of Physical Science and Technology
- Nanjing Normal University
- Nanjing 210023
- P. R. China
| | - Wei Shi
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Peng Cheng
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| |
Collapse
|
43
|
Greer SM, Gramigna KM, Thomas CM, Stoian SA, Hill S. Insights into Molecular Magnetism in Metal-Metal Bonded Systems as Revealed by a Spectroscopic and Computational Analysis of Diiron Complexes. Inorg Chem 2020; 59:18141-18155. [PMID: 33253552 DOI: 10.1021/acs.inorgchem.0c02605] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A pair of bimetallic compounds featuring Fe-Fe bonds, [Fe(iPrNPPh2)3FeR] (R = PMe3, ≡NtBu), have been investigated using High-Frequency Electron Paramagnetic Resonance (HFEPR) as well as field- and temperature-dependent 57Fe nuclear γ resonance (Mössbauer) spectroscopy. To gain insight into the local site electronic structure, we have concurrently studied a compound containing a single Fe(II) in a geometry analogous to that of one of the dimer sites. Our spectroscopic studies have allowed for the assessment of the electronic structure via the determination of the zero-field splitting and 57Fe hyperfine parameters for the entire series. We also report on our efforts to correlate structure with physical properties in metal-metal bonded systems using ligand field theory guided by quantum chemical calculations. Through the insight gained in this study, we discuss strategies for the design of single-molecule magnets based on polymetallic compounds linked via direct metal-metal bonds.
Collapse
Affiliation(s)
- Samuel M Greer
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States.,Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Kathryn M Gramigna
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02453, United States
| | - Christine M Thomas
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Sebastian A Stoian
- Department of Chemistry, University of Idaho, Moscow, Idaho 83844, United States
| | - Stephen Hill
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States.,Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| |
Collapse
|
44
|
Bao JJ, Zhou C, Varga Z, Kanchanakungwankul S, Gagliardi L, Truhlar DG. Multi-state pair-density functional theory. Faraday Discuss 2020; 224:348-372. [PMID: 32940325 DOI: 10.1039/d0fd00037j] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Multi-configuration pair-density functional theory (MC-PDFT) has previously been applied successfully to carry out ground-state and excited-state calculations. However, because they include no interaction between electronic states, MC-PDFT calculations in which each state's PDFT energy is calculated separately can give an unphysical double crossing of potential energy surfaces (PESs) in a region near a conical intersection. We have recently proposed state-interaction pair-density functional theory (SI-PDFT) to treat nearly degenerate states by creating a set of intermediate states with state interaction; although this method is successful, it is inconvenient because two SCF calculations and two sets of orbitals are required and because it puts the ground state on an unequal footing with the excited states. Here we propose two new methods, called extended-multi-state-PDFT (XMS-PDFT) and variational-multi-state-PDFT (VMS-PDFT), that generate the intermediate states in a balanced way with a single set of orbitals. The former uses the intermediate states proposed by Granovsky for extended multi-configuration quasi-degenerate perturbation theory (XMC-QDPT); the latter obtains the intermediate states by maximizing the sum of the MC-PDFT energies for the intermediate states. We also propose a Fourier series expansion to make the variational optimizations of the VMS-PDFT method convenient, and we implement this method (FMS-PDFT) both for conventional configuration-interaction solvers and for density-matrix-renormalization-group solvers. The new methods are tested for eight systems, exhibiting avoided crossings among two to six states. The FMS-PDFT method is successful for all cases for which it has been tested (all cases in this paper except O3 for which it was not tested), and XMS-PDFT is successful for all eight cases except the mixed-valence case. Since both XMS-PDFT and VMS-PDFT are less expensive than XMS-CASPT2, they will allow well-correlated calculations on much larger systems for which perturbation theory is unaffordable.
Collapse
Affiliation(s)
- Jie J Bao
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455-0431, USA.
| | | | | | | | | | | |
Collapse
|
45
|
Damgaard‐Møller E, Krause L, Tolborg K, Macetti G, Genoni A, Overgaard J. Quantification of the Magnetic Anisotropy of a Single‐Molecule Magnet from the Experimental Electron Density. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202007856] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Emil Damgaard‐Møller
- Department of Chemistry Aarhus University Langelandsgade 140 8000 Aarhus C Denmark
| | - Lennard Krause
- Department of Chemistry Aarhus University Langelandsgade 140 8000 Aarhus C Denmark
| | - Kasper Tolborg
- Department of Chemistry Aarhus University Langelandsgade 140 8000 Aarhus C Denmark
| | - Giovanni Macetti
- Université de Lorraine & CNRS Laboratoire de Physique et Chimie Théoriques (LPCT), UMR CNRS 7019 1 Boulevard Arago F-57078 Metz France
| | - Alessandro Genoni
- Université de Lorraine & CNRS Laboratoire de Physique et Chimie Théoriques (LPCT), UMR CNRS 7019 1 Boulevard Arago F-57078 Metz France
| | - Jacob Overgaard
- Department of Chemistry Aarhus University Langelandsgade 140 8000 Aarhus C Denmark
| |
Collapse
|
46
|
Damgaard-Møller E, Krause L, Tolborg K, Macetti G, Genoni A, Overgaard J. Quantification of the Magnetic Anisotropy of a Single-Molecule Magnet from the Experimental Electron Density. Angew Chem Int Ed Engl 2020; 59:21203-21209. [PMID: 33463025 DOI: 10.1002/anie.202007856] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/23/2020] [Indexed: 11/07/2022]
Abstract
Reported here is an entirely new application of experimental electron density (EED) in the study of magnetic anisotropy of single-molecule magnets (SMMs). Among those SMMs based on one single transition metal, tetrahedral CoII-complexes are prominent, and their large zero-field splitting arises exclusively from coupling between the d x 2 - y 2 and dxy orbitals. Using very low temperature single-crystal synchrotron X-ray diffraction data, an accurate electron density (ED) was obtained for a prototypical SMM, and the experimental d-orbital populations were used to quantify the dxy-d x 2 - y 2 coupling, which simultaneously provides the composition of the ground-state Kramers doublet wave function. Based on this experimentally determined wave function, an energy barrier for magnetic relaxation in the range 193-268 cm-1 was calculated, and is in full accordance with the previously published value of 230 cm-1 obtained from near-infrared spectroscopy. These results provide the first clear and direct link between ED and molecular magnetic properties.
Collapse
Affiliation(s)
- Emil Damgaard-Møller
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark
| | - Lennard Krause
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark
| | - Kasper Tolborg
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark
| | - Giovanni Macetti
- Université de Lorraine & CNRS, Laboratoire de Physique et Chimie Théoriques (LPCT), UMR CNRS 7019, 1 Boulevard Arago, F-57078, Metz, France
| | - Alessandro Genoni
- Université de Lorraine & CNRS, Laboratoire de Physique et Chimie Théoriques (LPCT), UMR CNRS 7019, 1 Boulevard Arago, F-57078, Metz, France
| | - Jacob Overgaard
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark
| |
Collapse
|
47
|
Sarkar A, Dey S, Rajaraman G. Role of Coordination Number and Geometry in Controlling the Magnetic Anisotropy in Fe II , Co II , and Ni II Single-Ion Magnets. Chemistry 2020; 26:14036-14058. [PMID: 32729641 DOI: 10.1002/chem.202003211] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Indexed: 12/22/2022]
Abstract
Since the last decade, the focus in the area of single-molecule magnets (SMMs) has been shifting constructively towards the development of single-ion magnets (SIMs) based on transition metals and lanthanides. Although ground-breaking results have been witnessed for DyIII -based SIMs, significant results have also been obtained for some mononuclear transition metal SIMs. Among others, studies based on CoII ion are very prominent as they often exhibit high magnetic anisotropy or zero-field splitting parameters and offer a large barrier height for magnetisation reversal. Although CoII possibly holds the record for having the largest number of zero-field SIMs known for any transition metal ion, controlling the magnetic anisotropy in these systems are is still a challenge. In addition to the modern spectroscopic techniques, theoretical studies, especially ab initio CASSCF/NEVPT2 approaches, have been used to uncover the electronic structure of various CoII SIMs. In this article, with some selected examples, the aim is to showcase how varying the coordination number from two to eight, and the geometry around the CoII centre alters the magnetic anisotropy. This offers some design principles for the experimentalists to target new generation SIMs based on the CoII ion. Additionally, some important FeII /FeIII and NiII complexes exhibiting large magnetic anisotropy and SIM properties are also discussed.
Collapse
Affiliation(s)
- Arup Sarkar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Sourav Dey
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400076, India
| |
Collapse
|
48
|
Huzan MS, Fix M, Aramini M, Bencok P, Mosselmans JFW, Hayama S, Breitner FA, Gee LB, Titus CJ, Arrio MA, Jesche A, Baker ML. Single-ion magnetism in the extended solid-state: insights from X-ray absorption and emission spectroscopy. Chem Sci 2020; 11:11801-11810. [PMID: 34123206 PMCID: PMC8162461 DOI: 10.1039/d0sc03787g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Large single-ion magnetic anisotropy is observed in lithium nitride doped with iron. The iron sites are two-coordinate, putting iron doped lithium nitride amongst a growing number of two coordinate transition metal single-ion magnets (SIMs). Uniquely, the relaxation times to magnetisation reversal are over two orders of magnitude longer in iron doped lithium nitride than other 3d-metal SIMs, and comparable with high-performance lanthanide-based SIMs. To understand the origin of these enhanced magnetic properties a detailed characterisation of electronic structure is presented. Access to dopant electronic structure calls for atomic specific techniques, hence a combination of detailed single-crystal X-ray absorption and emission spectroscopies are applied. Together K-edge, L2,3-edge and Kβ X-ray spectroscopies probe local geometry and electronic structure, identifying iron doped lithium nitride to be a prototype, solid-state SIM, clean of stoichiometric vacancies where Fe lattice sites are geometrically equivalent. Extended X-ray absorption fine structure and angular dependent single-crystal X-ray absorption near edge spectroscopy measurements determine FeI dopant ions to be linearly coordinated, occupying a D6h symmetry pocket. The dopant engages in strong 3dπ-bonding, resulting in an exceptionally short Fe–N bond length (1.873(7) Å) and rigorous linearity. It is proposed that this structure protects dopant sites from Renner–Teller vibronic coupling and pseudo Jahn–Teller distortions, enhancing magnetic properties with respect to molecular-based linear complexes. The Fe ligand field is quantified by L2,3-edge XAS from which the energy reduction of 3dz2 due to strong 4s mixing is deduced. Quantification of magnetic anisotropy barriers in low concentration dopant sites is inhibited by many established methods, including far-infrared and neutron scattering. We deduce variable temperature L3-edge XAS can be applied to quantify the J = 7/2 magnetic anisotropy barrier, 34.80 meV (∼280 cm−1), that corresponds with Orbach relaxation via the first excited, MJ = ±5/2 doublet. The results demonstrate that dopant sites within solid-state host lattices could offer a viable alternative to rare-earth bulk magnets and high-performance SIMs, where the host matrix can be tailored to impose high symmetry and control lattice induced relaxation effects. Taking advantage of synchrotron light source methods, we present the geometric and electronic structure of iron doped in lithium nitride.![]()
Collapse
Affiliation(s)
- Myron S Huzan
- The University of Manchester at Harwell, Diamond Light Source Harwell Campus OX11 0DE UK .,Department of Chemistry, The University of Manchester Manchester M13 9PL UK
| | - Manuel Fix
- EP VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg D-86159 Augsburg Germany
| | - Matteo Aramini
- Diamond Light Source, Harwell Science and Innovation Campus Chilton Didcot OX11 0DE UK
| | - Peter Bencok
- Diamond Light Source, Harwell Science and Innovation Campus Chilton Didcot OX11 0DE UK
| | | | - Shusaku Hayama
- Diamond Light Source, Harwell Science and Innovation Campus Chilton Didcot OX11 0DE UK
| | - Franziska A Breitner
- EP VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg D-86159 Augsburg Germany
| | - Leland B Gee
- Department of Chemistry, Stanford University Stanford CA 94305 USA
| | - Charles J Titus
- Department of Physics, Stanford University Stanford CA 94305 USA
| | - Marie-Anne Arrio
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS, Sorbonne Université, IRD, MNHN, UMR7590 75252 Paris Cedex 05 France
| | - Anton Jesche
- EP VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg D-86159 Augsburg Germany
| | - Michael L Baker
- The University of Manchester at Harwell, Diamond Light Source Harwell Campus OX11 0DE UK .,Department of Chemistry, The University of Manchester Manchester M13 9PL UK
| |
Collapse
|
49
|
Tsukerblat B, Palii A, Clemente-Juan JM, Coronado E. Modelling the properties of magnetic clusters with complex structures: how symmetry can help us. INT REV PHYS CHEM 2020. [DOI: 10.1080/0144235x.2020.1764778] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Boris Tsukerblat
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Andrew Palii
- Institute of Problems of Chemical Physics, Chernogolovka, Russia
- Institute of Applied Physics, Academy of Sciences of Moldova, Chisinau, Moldova
| | | | - Eugenio Coronado
- Instituto de Ciencia Molecular, Universidad de Valencia Paterna, SpainIn memory of Professor Peter Day
| |
Collapse
|
50
|
Smart Ligands for Efficient 3d-, 4d- and 5d-Metal Single-Molecule Magnets and Single-Ion Magnets. INORGANICS 2020. [DOI: 10.3390/inorganics8060039] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
There has been a renaissance in the interdisciplinary field of Molecular Magnetism since ~2000, due to the discovery of the impressive properties and potential applications of d- and f-metal Single-Molecule Magnets (SMMs) and Single-Ion Magnets (SIMs) or Monometallic Single-Molecule Magnets. One of the consequences of this discovery has been an explosive growth in synthetic molecular inorganic and organometallic chemistry. In SMM and SIM chemistry, inorganic and organic ligands play a decisive role, sometimes equally important to that of the magnetic metal ion(s). In SMM chemistry, bridging ligands that propagate strong ferromagnetic exchange interactions between the metal ions resulting in large spin ground states, well isolated from excited states, are preferable; however, antiferromagnetic coupling can also lead to SMM behavior. In SIM chemistry, ligands that create a strong axial crystal field are highly desirable for metal ions with oblate electron density, e.g., TbIII and DyIII, whereas equatorial crystal fields lead to SMM behavior in complexes based on metal ions with prolate electron density, e.g., ErIII. In this review, we have attempted to highlight the use of few, efficient ligands in the chemistry of transition-metal SMMs and SIMs, through selected examples. The content of the review is purely chemical and it is assumed that the reader has a good knowledge of synthetic, structural and physical inorganic chemistry, as well as of the properties of SIMs and SMMs and the techniques of their study. The ligands that will be discussed are the azide ion, the cyanido group, the tris(trimethylsilyl)methanide, the cyclopentanienido group, soft (based on the Hard-Soft Acid-Base model) ligands, metallacrowns combined with click chemistry, deprotonated aliphatic diols, and the family of 2-pyridyl ketoximes, including some of its elaborate derivatives. The rationale behind the selection of the ligands will be emphasized.
Collapse
|