1
|
Delano F, Benner F, Jang S, Greer SM, Demir S. Construction of intermolecular σ-hole interactions in rare earth metallocene complexes using a 2,3,4,5-tetraiodopyrrolyl anion. Chem Sci 2024; 15:13389-13404. [PMID: 39183902 PMCID: PMC11339973 DOI: 10.1039/d4sc03786c] [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: 06/10/2024] [Accepted: 06/29/2024] [Indexed: 08/27/2024] Open
Abstract
The generation of noncovalent intermolecular interactions represents a powerful method to control molecular vibrations and rotations. Combining these with the axial ligand field enforced by the metallocene ligand scaffold provides a dual-pronged approach in controlling the magnetic-relaxation pathways for dysprosium-based single-molecule magnets (SMMs). Here, we present the first implementation of 2,3,4,5-tetraiodopyrrole (TIPH) in its anionic form [TIP]- as a ligand in three isostructural rare-earth metal complexes Cp*2RE(TIP) (1-RE, RE = Y, Gd, and Dy; Cp* = pentamethylcylopentadienyl), where the TIP ligand binds through the nitrogen and one iodine atom κ2(N,I) to the metal centre. The shallow potential energy surface of the intermolecular σ-hole interaction yields distortions of the interatomic distances at elevated temperatures which were investigated by variable-temperature SCXRD. 1-RE constitute the first crystallographically characterized molecules containing TIP as a ligand for any metal ion, and 1-Dy is the first SMM that employs the TIP ligand. The structural dependence on temperature allowed the mechanism of magnetic relaxation to be explored through ab initio calculations at different temperatures. The electronic influence of the coordinated iodine substituent was probed via magnetometry and cw-EPR spectroscopy on 1-Gd. To further scrutinize the impact of the iodine substituents on the physical properties, a second set of new complexes Cp*2RE(DMP) (2-RE, RE = Y, and Dy) where DMP = 2,5-dimethylpyrrolyl were synthesized. Here, the DMP ligand binds similarly to the TIP ligand and represents an all-hydrocarbon analogue to 1-RE. 2-Dy constitutes the first SMM bearing a DMP ligand.
Collapse
Affiliation(s)
- Francis Delano
- Department of Chemistry, Michigan State University 578 South Shaw Lane East Lansing Michigan 48824 USA
| | - Florian Benner
- Department of Chemistry, Michigan State University 578 South Shaw Lane East Lansing Michigan 48824 USA
| | - Seoyun Jang
- Department of Chemistry, Michigan State University 578 South Shaw Lane East Lansing Michigan 48824 USA
| | - Samuel M Greer
- Los Alamos National Laboratory (LANL) Los Alamos New Mexico 87545 USA
| | - Selvan Demir
- Department of Chemistry, Michigan State University 578 South Shaw Lane East Lansing Michigan 48824 USA
| |
Collapse
|
2
|
Lussier D, Ito E, McClain KR, Smith PW, Kwon H, Rutkauskaite R, Harvey BG, Shuh DK, Long JR. Metal-Halide Covalency, Exchange Coupling, and Slow Magnetic Relaxation in Triangular (Cp iPr5) 3U 3X 6 (X = Cl, Br, I) Clusters. J Am Chem Soc 2024; 146:21280-21295. [PMID: 39044394 PMCID: PMC11311243 DOI: 10.1021/jacs.3c11678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 07/08/2024] [Accepted: 07/10/2024] [Indexed: 07/25/2024]
Abstract
The actinide elements are attractive alternatives to transition metals or lanthanides for the design of exchange-coupled multinuclear single-molecule magnets. However, the synthesis of such compounds is challenging, as is unraveling any contributions from exchange coupling to the overall magnetism. To date, only a few actinide compounds have been shown to exhibit exchange coupling and single-molecule magnetism. Here, we report triangular uranium(III) clusters of the type (CpiPr5)3U3X (1-X; X = Cl, Br, I; CpiPr5 = pentaisopropylcyclopentadienyl), which are synthesized via reaction of the aryloxide-bridged precursor (CpiPr5)2U2(OPhtBu)4 with excess Me3SiX. Spectroscopic analysis suggests the presence of covalency in the uranium-halide interactions arising from 5f orbital participation in bonding. The dc magnetic susceptibility data reveal the presence of antiferromagnetic exchange coupling between the uranium(III) centers in these compounds, with the strength of the exchange decreasing down the halide series. Ac magnetic susceptibility data further reveal all compounds to exhibit slow magnetic relaxation under zero dc field. In 1-I, which exhibits particularly weak exchange, magnetic relaxation occurs via a Raman mechanism associated with the individual uranium(III) centers. In contrast, for 1-Br and 1-Cl, magnetic relaxation occurs via an Orbach mechanism, likely involving relaxation between ground and excited exchange-coupled states. Significantly, in the case of 1-Cl, magnetic relaxation is sufficiently slow such that open magnetic hysteresis is observed up to 2.75 K, and the compound exhibits a 100-s blocking temperature of 2.4 K. This compound provides the first example of magnetic blocking in a compound containing only actinide-based ions, as well as the first example involving the uranium(III) oxidation state.
Collapse
Affiliation(s)
- Daniel
J. Lussier
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Emi Ito
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - K. Randall McClain
- U.S.
Navy, Naval Air Warfare Center, Weapons Division, Research Department, Chemistry Division, China Lake, California 93555, United States
| | - Patrick W. Smith
- Chemical
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Hyunchul Kwon
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Ryte Rutkauskaite
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Benjamin G. Harvey
- U.S.
Navy, Naval Air Warfare Center, Weapons Division, Research Department, Chemistry Division, China Lake, California 93555, United States
| | - David K. Shuh
- Chemical
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Jeffrey R. Long
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| |
Collapse
|
3
|
Braun J, Powell AK, Unterreiner AN. Gaining Insights into the Interplay between Optical and Magnetic Properties in Photoexcited Coordination Compounds. Chemistry 2024; 30:e202400977. [PMID: 38693865 DOI: 10.1002/chem.202400977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/19/2024] [Accepted: 04/30/2024] [Indexed: 05/03/2024]
Abstract
We describe early and recent advances in the fascinating field of combined magnetic and optical properties of inorganic coordination compounds and in particular of 3d-4f single molecule magnets. We cover various applied techniques which allow for the correlation of results obtained in the frequency and time domain in order to highlight the specific properties of these compounds and the future challenges towards multidimensional spectroscopic tools. An important point is to understand the details of the interplay of magnetic and optical properties through performing time-resolved studies in the presence of external fields especially magnetic ones. This will enable further exploration of this fundamental interactions i. e. the two components of electromagnetic radiation influencing optical properties.
Collapse
Affiliation(s)
- Jonas Braun
- Institute of Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
- Institute for Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
| | - Annie K Powell
- Institute of Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
- Institute for Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
| | - Andreas-Neil Unterreiner
- Institute of Physical Chemistry (IPC), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
| |
Collapse
|
4
|
Zhu Z, Paul S, Zhao C, Wu J, Ying X, Ungur L, Wernsdorfer W, Meyer F, Tang J. Record Quantum Tunneling Time in an Air-Stable Exchange-Bias Dysprosium Macrocycle. J Am Chem Soc 2024; 146:18899-18904. [PMID: 38975975 DOI: 10.1021/jacs.4c07412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
In recent years, dysprosium macrocycle single-molecule magnets (SMMs) have received increasing attention due to their excellent air/thermal stability, strong magnetic anisotropy, and rigid molecular skeleton. However, they usually display fast zero-field quantum tunneling of the magnetization (QTM) rate, severely hindering their data storage applications. Herein, we report the design, synthesis, and characterization of an air-stable monodecker didysprosium macrocycle integrating strong single-ion anisotropy, near-perfect local crystal field (CF) symmetry, and efficient exchange bias. These indispensable features enable clear-cut elucidation of the crucial role of very weak antiferromagnetic coupling on magnetization dynamics, creating a prominent SMM with a large effective energy barrier (Ueff) of 670 cm-1, open hysteresis loops at zero field up to 14.9 K, and a record relaxation time of QTM (τQTM), 24281 s, for all known nonradical-bridged lanthanide SMMs.
Collapse
Affiliation(s)
- Zhenhua Zhu
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Sagar Paul
- Physikalisches Institut, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, D-76131, Karlsruhe, Germany
| | - Chen Zhao
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Jianfeng Wu
- School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710072, P. R. China
| | - Xu Ying
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Liviu Ungur
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Wolfgang Wernsdorfer
- Physikalisches Institut, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, D-76131, Karlsruhe, Germany
| | - Franc Meyer
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstraße 4, D-37077 Göttingen, Germany
| | - Jinkui Tang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
| |
Collapse
|
5
|
Bajaj N, Kitos AA, Mavragani N, Loutsch NR, Vlaisavljevich B, Murugesu M. Formation of a Decanuclear Organometallic Dysprosium Complex via a Radical-Radical Cross-Coupling Reaction. Angew Chem Int Ed Engl 2024:e202411635. [PMID: 38963679 DOI: 10.1002/anie.202411635] [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: 06/20/2024] [Revised: 07/02/2024] [Accepted: 07/02/2024] [Indexed: 07/05/2024]
Abstract
Over the years, polynuclear cyclic or torus complexes have attracted increasing interest due to their unique metal topologies and properties. However, the isolation of polynuclear cyclic organometallic complexes is extremely challenging due to their inherent reactivity, which stems from the labile and reactive metal-carbon bonds. In this study, the pyrazine ligand undergoes a radical-radical cross-coupling reaction leading to the formation of a decanuclear [(Cp*)20Dy10(L1)10] ⋅ 12(C7H8) (1; where L1 = anion of 2-prop-2-enyl-2H-pyrazine; Cp* = pentamethylcyclopentadienyl) complex, where all DyIII metal centres are bridged by the anionic L1 ligand. Amongst the family of polynuclear Ln organometallic complexes bearing CpR 2Lnx units (CpR = substituted cyclopentadienyl), 1 features the highest nuclearity obtained to date. In-depth computational studies were conducted to elucidate the proposed reaction mechanism and formation of L1, while probing of the magnetic properties of 1, revealed slow magnetic relaxation upon application of a static dc field.
Collapse
Affiliation(s)
- Neha Bajaj
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| | - Alexandros A Kitos
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| | - Niki Mavragani
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| | - Nathan R Loutsch
- Department of Chemistry, University of South Dakota, 414 E Clark St, Vermillion, South Dakota, 57069, United States
| | - Bess Vlaisavljevich
- Department of Chemistry, University of South Dakota, 414 E Clark St, Vermillion, South Dakota, 57069, United States
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| |
Collapse
|
6
|
Hunger D, Suhr S, Bayer V, Albold U, Frey W, Sarkar B, van Slageren J. Precursor molecules for 1,2-diamidobenzene containing cobalt(II), nickel(II) and zinc(II) complexes - synthesis and magnetic properties. Dalton Trans 2024; 53:9852-9861. [PMID: 38804996 DOI: 10.1039/d4dt01115e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Molecular magnetic materials based on 1,2-diamidobenzenes are well known and have been intensively studied both experimentally and computationally. They possess interesting magnetic properties as well as redox activity. In this work, we present the synthesis and investigation of potent synthons for constructing discrete metal-organic architectures featuring 1,2-diamidobenzene-coordinated metal centres. The synthons feature weakly bound dimethoxyethane (dme) ligands in addition to the 1,2-diamidobenzene. We characterize these complexes and investigate their magnetic properties by means of static and dynamic magnetometry and high-field electron paramagnetic resonance (HFEPR). Interestingly, the magnetic and magnetic resonance data strongly suggest a dimeric formulation of these complexes, viz. [MII(bmsab)(dme)]2 (bmsab = 1,2-bis(methanesulfonamido)benzene; dme = dimethoxyethane) with M = Co, Ni, Zn. A large negative D-value of -60 cm-1 was found for the Co(II) synthon and an equally large negative D of -50 cm-1 for the Ni(II) synthon. For Co(II), the sign of the D-value is the same as that found for the known bis-diamidobenzene complexes of this ion. In contrast, the negative D-value for the Ni(II) complex is unexpected, which we explain in terms of a change in coordination number. The heteroleptic Co(II) complex presented here does not feature slow relaxation of the magnetization, in contrast to the homoleptic Co(II) 1,2-diamidobenzene complex.
Collapse
Affiliation(s)
- David Hunger
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| | - Simon Suhr
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| | - Valentin Bayer
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| | - Uta Albold
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, 14195 Berlin, Germany
| | - Wolfgang Frey
- Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Biprajit Sarkar
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| | - Joris van Slageren
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| |
Collapse
|
7
|
Corner S, Gransbury GK, Vitorica-Yrezabal IJ, Whitehead GFS, Chilton NF, Mills DP. Halobenzene Adducts of a Dysprosocenium Single-Molecule Magnet. Inorg Chem 2024; 63:9552-9561. [PMID: 38359351 PMCID: PMC11134494 DOI: 10.1021/acs.inorgchem.3c04105] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/18/2024] [Accepted: 01/23/2024] [Indexed: 02/17/2024]
Abstract
Dysprosium complexes with strong axial crystal fields are promising candidates for single-molecule magnets (SMMs), which could be used for high-density data storage. Isolated dysprosocenium cations, [Dy(CpR)2]+ (CpR = substituted cyclopentadienyl), have recently shown magnetic hysteresis (a memory effect) above the temperature of liquid nitrogen. Synthetic efforts have focused on reducing strong transverse ligand fields in these systems as they are known to enhance magnetic relaxation by spin-phonon mechanisms. Here we show that equatorial coordination of the halobenzenes PhX (X = F, Cl, Br) and o-C6H4F2 to the cation of a recently reported dysprosocenium complex [Dy(Cpttt)(Cp*)][Al{OC(CF3)3}4] (Cpttt = C5H2tBu3-1,2,4; Cp* = C5Me5) reduces magnetic hysteresis temperatures compared to that of the parent cation. We find that this is due to increased effectiveness of both one- (Orbach) and two-phonon (Raman) relaxation mechanisms, which correlate with the electronegativity and number of interactions with the halide despite κ1-coordination of a single halobenzene having a minimal effect on the metrical parameters of [Dy(Cpttt)(Cp*)(PhX-κ1-X)]+ cations vs the isolated [Dy(Cpttt)(Cp*)]+ cation. We observe unusual divergent behavior of relaxation rates at low temperatures in [Dy(Cpttt)(Cp*)(PhX)][Al{OC(CF3)3}4], which we attribute to a phonon bottleneck effect. We find that, despite the transverse fields introduced by the monohalobenzenes in these cations, the interactions are sufficiently weak that the effective barriers to magnetization reversal remain above 1000 cm-1, being only ca. 100 cm-1 lower than for the parent complex, [Dy(Cpttt)(Cp*)][Al{OC(CF3)3}4].
Collapse
Affiliation(s)
| | | | | | - George F. S. Whitehead
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | | | - David P. Mills
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| |
Collapse
|
8
|
Corner S, Gransbury GK, Vitorica-Yrezabal IJ, Whitehead GFS, Chilton NF, Mills DP. Synthesis and Magnetic Properties of Bis-Halobenzene Decamethyldysprosocenium Cations. Inorg Chem 2024; 63:9562-9571. [PMID: 38382535 PMCID: PMC11134500 DOI: 10.1021/acs.inorgchem.3c04106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/18/2024] [Accepted: 01/23/2024] [Indexed: 02/23/2024]
Abstract
The decamethyldysprosocenium cation, [Dy(Cp*)2]+ (Cp* = {C5Me5}), was a target single-molecule magnet (SMM) prior to the isolation of larger dysprosocenium cations, which have recently shown magnetic memory effects up to 80 K. However, the relatively short Dy···Cp*centroid distances of [Dy(Cp*)2]+, together with the reduced resonance of its vibrational modes with electronic states compared to larger dysprosocenium cations, could lead to more favorable SMM behavior. Here, we report the synthesis and magnetic properties of a series of solvated adducts containing bis-halobenzene decamethyldysprosocenium cations, namely [Dy(Cp*)2(PhX-κ-X)2][Al{OC(CF3)3}4] (X = F or Cl) and [Dy(Cp*)2(C6H4F2-κ2-F,F)(C6H4F2-κ-F)][Al{OC(CF3)3}4]. These complexes were prepared by the sequential reaction of [Dy(Cp*)2(μ-BH4)]∞ with allylmagnesium chloride and [NEt3H][Al{OC(CF3)3}4], followed by recrystallization from parent halobenzenes. The complexes were characterized by powder and single crystal X-ray diffraction, NMR and ATR-IR spectroscopy, elemental analysis, and SQUID magnetometry; experimental data were rationalized by a combination of density functional theory and ab initio calculations. We find that bis-halobenzene adducts of the [Dy(Cp*)2]+ cation exhibit highly bent Cp*···Dy···Cp* angles; these cations are also susceptible to decomposition by C-X (X = F, Cl, Br) activation and displacement of halobenzenes by O-donor ligands. The effective energy barrier to reversal of magnetization measured for [Dy(Cp*)2(PhF-κ-F)2][Al{OC(CF3)3}4] (930(6) cm-1) sets a new record for SMMs containing {Dy(Cp*)2} fragments, though all SMM parameters are lower than would be predicted for an isolated [Dy(Cp*)2]+ cation, as expected due to transverse ligand fields introduced by halobenzenes and the large deviation of the Cp*···Dy···Cp* angle from linearity promoting magnetic relaxation.
Collapse
Affiliation(s)
- Sophie
C. Corner
- Department of Chemistry, The
University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Gemma K. Gransbury
- Department of Chemistry, The
University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | | | - George F. S. Whitehead
- Department of Chemistry, The
University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | | | - David P. Mills
- Department of Chemistry, The
University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| |
Collapse
|
9
|
Delano F, Deshapriya S, Demir S. Guanidinate Yttrium Complexes Containing Bipyridyl and Bis(benzimidazolyl) Radicals. Inorg Chem 2024; 63:9659-9669. [PMID: 38569134 PMCID: PMC11134503 DOI: 10.1021/acs.inorgchem.4c00006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 02/26/2024] [Accepted: 03/06/2024] [Indexed: 04/05/2024]
Abstract
Ancillary ligand scaffolds that sufficiently stabilize a metal ion to allow its coordination to an open-shell ligand are scarce, yet their development is essential for next-generation spin-based materials with topical applications in quantum information science. To this end, a synthetic challenge must be met: devising molecules that enable the binding of a redox-active ligand through facile displacement and clean removal of a weakly coordinating anion. Here, we probe the accessibility of unprecedented radical-containing rare-earth guanidinate complexes by combining our recently discovered yttrium tetraphenylborate complex [{(Me3Si)2NC(NiPr)2}2Y][(μ-η6-Ph)(BPh3)] with the redox-active ligands 2,2'-bipyridine (bpy) and 2,2'-bis(benzimidazole) (Bbim), respectively, under reductive conditions. Our endeavor resulted in the first evidence of guanidinate complexes that contain radicals, namely, a mononuclear bipyridyl radical complex, {(Me3Si)2NC(NiPr)2}2Y(bpy•) (1), and a dinuclear bis(benzimidazolyl) radical-bridged complex, [K(crypt-222)][{(Me3Si)2NC(NiPr)2}2Y]2(μ-Bbim•) (2'). The latter was achieved by an in situ reduction of [{(Me3Si)2NC(NiPr)2}2Y]2(μ-Bbim) (2), which was isolated from a salt metathesis reaction. 1 and 2 were characterized by X-ray crystallography and IR and UV-vis spectroscopy. Variable-temperature electron paramagnetic resonance spectroscopy was applied to gain insight into the distribution of unpaired spin density on 1 and 2'. Density functional theory calculations were conducted on 1 and 2' to elucidate further their electronic structures. The redox activity of 1 and 2' was also probed by electrochemical methods.
Collapse
Affiliation(s)
| | | | - Selvan Demir
- Department of Chemistry, Michigan
State University (MSU), 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| |
Collapse
|
10
|
Flichot H, Sickinger A, Brom J, Lefeuvre B, Dorcet V, Guizouarn T, Cador O, Le Guennic B, Micouin L, Maury O, Benedetti E, Pointillart F. Magneto-structural correlation in lanthanide luminescent [2.2]paracyclophane-based single-molecule magnets. Dalton Trans 2024; 53:8191-8201. [PMID: 38687018 DOI: 10.1039/d4dt00536h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
The association of lanthanide ions and paracyclophane derivatives has been very scarcely reported in the literature. In this study, elaboration of five coordination lanthanide complexes involving the 1,4(1,4)-dibenzenacyclohexaphane-12,43-diylbis(diphenylphosphine oxide) ligand (L) was achieved with the determination of single-crystal X-ray diffraction structures of four mononuclear complexes of formula [Ln(hfac)3(L)] (hfac- = 1,1,1,5,5,5-hexafluoroacetylacetonate) (Ln = Dy(III) (1-Dy) and Yb(III) (2-Yb)) and [Ln(tta)3(L)] (tta- = 2-tenoyl-trifluoroacetylacetonate) (Ln = Dy(III) (3-Dy) and Yb(III) (4-Yb)) and one dinuclear complex [Na(Dy2(hfac)6(L)2)](BArF) (BArF- = tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) (5-Dy). The compounds were characterized using elemental analysis, IR spectroscopy, DC and AC magnetic measurements and photophysical investigations. L is an efficient organic chromophore for the sensitization of both visible Dy(III) (1-Dy) and near-infrared Yb(III) (2-Yb and 4-Yb) luminescence. The combination of excitation and emission spectra allowed the determination of the crystal field spitting of both the 2F7/2 ground state and 2F5/2 excited state for 2-Yb and 4-Yb. Moreover, 3-Dy and the two Yb(III) derivatives displayed field-induced single-molecule magnet (SMM) behaviour with slow magnetic relaxation occurring through the Raman process only for 2-Yb and 4-Yb, whereas a combination of Orbach and Raman processes was identified for 3-Dy.
Collapse
Affiliation(s)
- Hadrien Flichot
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000 Rennes, France.
| | - Annika Sickinger
- Univ Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5182, Laboratoire de Chimie, Lyon F-69342, France
| | - Jules Brom
- Université Paris Cité, CNRS, Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, F-75006 Paris, France.
| | - Bertrand Lefeuvre
- 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.
| | - Thierry Guizouarn
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000 Rennes, France.
| | - Olivier Cador
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000 Rennes, France.
| | - Boris Le Guennic
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000 Rennes, France.
| | - Laurent Micouin
- Université Paris Cité, CNRS, Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, F-75006 Paris, France.
| | - Olivier Maury
- Univ Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5182, Laboratoire de Chimie, Lyon F-69342, France
| | - Erica Benedetti
- Université Paris Cité, CNRS, Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, F-75006 Paris, France.
| | - Fabrice Pointillart
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000 Rennes, France.
| |
Collapse
|
11
|
David G, Duplaix-Rata G, Le Guennic B. What governs magnetic exchange couplings in radical-bridged dinuclear complexes? Phys Chem Chem Phys 2024; 26:8952-8964. [PMID: 38436408 DOI: 10.1039/d3cp06243k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2024]
Abstract
Coupling transition metal or lanthanide ions through a radical bridging ligand is a promising route to increase performances in the area of single molecular magnets. A better understanding of the underlying physical mechanisms governing the magnetic exchange couplings is thus of valuable importance to design future compounds. Here, couplings in three series of metal-radical-metal compounds based on transition metal ions are investigated by means of the decomposition/recomposition methods. This work presents the generalisation and first application of the method to systems with an arbitrary number of magnetic centres featuring several unpaired electrons. Thanks to the decomposition into the three main contributions (direct exchange, kinetic exchange, and spin polarisation) as well as a description in terms of electron-electron interactions, we study the influence of the nature of the metal centre and the radical ligand on the couplings. We combine the energetic contributions extracted with orbital and charge population analysis to rationalise the results.
Collapse
Affiliation(s)
- Grégoire David
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France.
| | - Gwenhaël Duplaix-Rata
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France.
| | - Boris Le Guennic
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France.
| |
Collapse
|
12
|
Hu SX, Liu HT, Cao LZ, Chen XT, Guan PF, Zhang P. Distinguishing the Geometric and Electronic Structures of Actinide Carbides An xC 8 (An = Th, U; x = 2, 3) through Exchange Interactions. J Phys Chem A 2024; 128:829-839. [PMID: 38266177 DOI: 10.1021/acs.jpca.3c06060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024]
Abstract
Global-minimum optimizations combined with relativistic quantum chemistry calculations have been performed to characterize the ground-state stable structures of four titled compounds and to analyze the bonding properties. Th2C8 was identified as being a ThC4-Th(C2)2 structure, U2C8 has been found to favor the U-U(C8) structure, and both Th3C8 and U3C8 adopt the (AnC3)2-(AnC2) structure. Then, the wave function analyses reveal that the interactions between the Th 7s-based orbital and the σg molecular orbital of the C2 unit compensate for the excitation energy of 7s16d1 → 6d2 and lead to the stabilization of two Th(IV)s in the ThC4-Th(C2)2 structure. It also reveals that the U species exhibit magnetic exchange coupling behavior in UxC8, for instance, as seen in the direct interaction of U2C8 and the superexchange pathway of U3C8, which effectively stabilizes their low-spin states. This interpretation indicates that the geometric and electronic structures of AnxC8 species are largely influenced by the local magnetic moment and spin correlation.
Collapse
Affiliation(s)
- Shu-Xian Hu
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
- Beijing Computational Science Research Center, Beijing 100193, China
| | - Hai-Tao Liu
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
| | - Ling-Zhi Cao
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Xiao-Tong Chen
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Peng-Fei Guan
- Beijing Computational Science Research Center, Beijing 100193, China
| | - Ping Zhang
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
| |
Collapse
|
13
|
Arumugam S, Schwarz B, Ravichandran P, Kumar S, Ungur L, Mondal KC. Dipotassiumtetrachloride-bridged dysprosium metallocenes: a single-molecule magnet. Dalton Trans 2023; 52:15326-15333. [PMID: 37387215 DOI: 10.1039/d3dt01325a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Abstract
The present work describes the dynamic magnetic properties of the complex [(CpAr3)4DyIII2Cl4K2]·3.5(C7H8) (1), synthesized by employing a tri-aryl-substituted cyclopentadienyl ligand (CpAr3), [4,4'-(4-phenylcyclopenta-1,3-diene-1,2-diyl)bis(methylbenzene) = CpAr3H]. Each Dy(III)-metallocene weakly couples via K2Cl4, displaying slow relaxation of magnetization below 14.5 K under zero applied dc field via KD3 energy levels with an energy barrier of 136.9/133.7 cm-1 on the Dy sites. The single-ion axial anisotropy energy barrier is reduced by geometrical distortion due to the coordination of two chloride ions at each Dy centre.
Collapse
Affiliation(s)
- Selvakumar Arumugam
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, India.
| | - 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.
| | | | - Sunil Kumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, India.
| | - Liviu Ungur
- Department of Chemistry, National University of Singapore, Singapore.
| | | |
Collapse
|
14
|
Gransbury G, Corner SC, Kragskow JGC, Evans P, Yeung HM, Blackmore WJA, Whitehead GFS, Vitorica-Yrezabal IJ, Oakley MS, Chilton NF, Mills DP. AtomAccess: A Predictive Tool for Molecular Design and Its Application to the Targeted Synthesis of Dysprosium Single-Molecule Magnets. J Am Chem Soc 2023; 145:22814-22825. [PMID: 37797311 PMCID: PMC10591469 DOI: 10.1021/jacs.3c08841] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Indexed: 10/07/2023]
Abstract
Isolated dysprosocenium cations, [Dy(CpR)2]+ (CpR = substituted cyclopentadienyl), have recently been shown to exhibit superior single-molecule magnet (SMM) properties over closely related complexes with equatorially bound ligands. However, gauging the crossover point at which the CpR substituents are large enough to prevent equatorial ligand binding, but small enough to approach the metal closely and generate strong crystal field splitting has required laborious synthetic optimization. We therefore created the computer program AtomAccess to predict the accessibility of a metal binding site and its ability to accommodate additional ligands. Here, we apply AtomAccess to identify the crossover point for equatorial coordination in [Dy(CpR)2]+ cations in silico and hence predict a cation that is at the cusp of stability without equatorial interactions, viz., [Dy(Cpttt)(Cp*)]+ (Cpttt = C5H2tBu3-1,2,4, Cp* = C5Me5). Upon synthesizing this cation, we found that it crystallizes as either a contact ion-pair, [Dy(Cpttt)(Cp*){Al[OC(CF3)3]4-κ-F}], or separated ion-pair polymorph, [Dy(Cpttt)(Cp*)][Al{OC(CF3)3}4]·C6H6. Upon characterizing these complexes, together with their precursors, yttrium and yttrium-doped analogues, we find that the contact ion-pair shows inferior SMM properties to the separated ion-pair, as expected, due to faster Raman and quantum tunneling of magnetization relaxation processes, while the Orbach region is relatively unaffected. The experimental verification of the predicted crossover point for equatorial coordination in this work tests the limitations of the use of AtomAccess as a predictive tool and also indicates that the application of this type of program shows considerable potential to boost efficiency in exploratory synthetic chemistry.
Collapse
Affiliation(s)
| | | | - Jon G. C. Kragskow
- Department of Chemistry, The
University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Peter Evans
- Department of Chemistry, The
University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Hing Man Yeung
- Department of Chemistry, The
University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - William J. A. Blackmore
- Department of Chemistry, The
University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - George F. S. Whitehead
- Department of Chemistry, The
University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | | | - Meagan S. Oakley
- Department of Chemistry, The
University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Nicholas F. Chilton
- Department of Chemistry, The
University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - David P. Mills
- Department of Chemistry, The
University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| |
Collapse
|
15
|
Mondal A, Price CG, Tang J, Layfield RA. Targeted Synthesis of End-On Dinitrogen-Bridged Lanthanide Metallocenes and Their Reactivity as Divalent Synthons. J Am Chem Soc 2023; 145:20121-20131. [PMID: 37656516 PMCID: PMC10510326 DOI: 10.1021/jacs.3c07600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Indexed: 09/03/2023]
Abstract
High-yield syntheses of the lanthanide dinitrogen complexes [(Cp2tttM)2(μ-1,2-N2)] (1M, M = Gd, Tb, Dy; Cpttt = 1,2,4-C5tBu3H2), in which the [N2]2- ligands solely adopt the rare end-on or 1,2-bridging mode, are reported. The bulk of the tert-butyl substituents and the smaller radii of gadolinium, terbium, and dysprosium preclude formation of the side-on dinitrogen bonding mode on steric grounds. Elongation of the nitrogen-nitrogen bond relative to N2 is observed in 1M, and their Raman spectra show a major absorption consistent with N═N double bonds. Computational analysis of 1Gd identifies that the local symmetry of the metallocene units lifts the degeneracy of two 5dπ orbitals, leading to differing overlap with the π* orbitals of [N2]2-, a consequence of which is that the dinitrogen ligand occupies a singlet ground state. Magnetic measurements reveal antiferromagnetic exchange in 1M and single-molecule magnet (SMM) behavior in 1Dy. Ab initio calculations show that the magnetic easy axis in the ground doublets of 1Tb and 1Dy align with the {M-N═N-M} connectivity, in contrast to the usual scenario in dysprosium metallocene SMMs, where the axis passes through the cyclopentadienyl ligands. The [N2]2- ligands in 1M allow these compounds to be regarded as two-electron reducing agents, serving as synthons for divalent gadolinium, terbium, and dysprosium. Proof of principle for this concept is obtained in the reactions of 1M with 2,2'-bipyridyl (bipy) to give [Cp2tttM(κ2-bipy)] (2M, M = Gd, Tb, Dy), in which the lanthanide is ligated by a bipy radical anion, with strong metal-ligand direct exchange coupling.
Collapse
Affiliation(s)
- Arpan Mondal
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QJ, U.K.
| | - Christopher G.
T. Price
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QJ, U.K.
| | - Jinkui Tang
- State
Key Laboratory of Rare Earth Resource Utilization, Changchun Institute
of Applied Chemistry, Chinese Academy of
Sciences, Changchun 130022, P.R. China
| | - Richard A. Layfield
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QJ, U.K.
| |
Collapse
|
16
|
Delano F, Benner F, Jang S, Demir S. Pyrrolyl-Bridged Metallocene Complexes: From Synthesis, Electronic Structure, to Single-Molecule Magnetism. Inorg Chem 2023; 62:14604-14614. [PMID: 37638984 DOI: 10.1021/acs.inorgchem.3c01724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/29/2023]
Abstract
The π- and σ-basicity of the pyrrolyl ligand affords several coordination modes. A sterically encumbering coordination sphere around metal centers may foster new coordination modes for the pyrrolyl ligand. Here, we present three dinuclear rare earth complexes [Cp*2RE(μ-pyr)]2, [RE = Y (1), La (2), Dy (3); Cp* = pentamethylcyclopentadienyl, pyr = pyrrolyl], which were synthesized through a protonolysis reaction between allyl complexes and H-pyrrole. Each metal is ligated by two Cp* ligands and the N atom of the pyrrolyl ring while interacting with the π-system of the other pyrrolyl ligand, yielding an unprecedented coordination mode for pyrrolyl best described as [((η5-Cp*)2RE)2(μ-1η2-pyr-2κN)(μ-2η2-pyr-1κN)]. The steric congestion implemented by the Cp* ligands forces this asymmetric coordination of the pyrrolyl ligand. 1-3 were characterized by crystallography, electrochemistry, and spectroscopy. Density functional theory calculations on 1 uncovered the bonding situation between the pyrrolyl ligand and the yttrium(III) ion. Excitingly, 3 displays slow magnetic relaxation under zero dc field with Ueff = 98.9(7) cm-1 and τo = 6.7(1) × 10-8 s, placing it among coveted dinuclear metallocene single-molecule magnets. CASSCF calculations provided the energy of the crystal field states of DyIII and confirmed the barrier height.
Collapse
Affiliation(s)
- Francis Delano
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Florian Benner
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Seoyun Jang
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Selvan Demir
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| |
Collapse
|
17
|
Lefeuvre B, Guizouarn T, Dorcet V, Cordier M, Pointillart F. Single-Molecule Magnet Properties in 3 d4 f Heterobimetallic Iron and Dysprosium Complexes Involving Hydrazone Ligand. Molecules 2023; 28:6359. [PMID: 37687187 PMCID: PMC10489976 DOI: 10.3390/molecules28176359] [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: 07/20/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
The reaction between the ((E)-N'-(2-hydroxy-3-methoxybenzylidene)pyrazine-2-carbohydrazide) (H2opch) ligand and the metallo-precursor [Dy(hfac)3]·2H2O led to the formation of an homometallic coordination complex with the formula [Dy2(hfac)3(H2O)(Hopch)2][Dy(hfac)4] (1). In presence of both [Dy(hfac)3] 2H2O and the Fe(II) salt, the heterobimetallic tetranuclear [FeDy3(hfac)8(H2O)2(opch)2] (2) was isolated, while the addition of the co-ligand 1,2-Bis(2-hydroxy-3-methoxybenzylidene) hydrazine (H2bmh) led to the formation of two heterobimetallic tetranuclear complexes with the formula [Fe3Dy(hfac)6(opch)2(H2bmh)] C6H14 (3) C6H14 and [Fe2Dy2(hfac)7(opch)2(H2bmh)] 0.5C7H16 (4) 0.5C7H16. Single crystal X-ray diffraction and dc magnetic investigation demonstrated that 3 and 4 involved the iron center in the +II and +III oxidation states. Dynamic magnetic measurements highlighted the single-molecule magnet behavior of 1 and 2 in a zero applied dc field primarily due to the ferromagnetic interactions taking place in these compounds.
Collapse
Affiliation(s)
| | | | | | | | - Fabrice Pointillart
- CNRS, ISCR (Institut des Sciences Chimiques de Rennes)—UMR 6226, University of Rennes, 35000 Rennes, France; (B.L.); (T.G.); (V.D.); (M.C.)
| |
Collapse
|
18
|
Dai JW, Li YQ, Li ZY, Zhang HT, Herrmann C, Kumagai S, Damjanović M, Enders M, Nojiri H, Morimoto M, Hoshino N, Akutagawa T, Yamashita M. Dual-radical-based molecular anisotropy and synergy effect of semi-conductivity and valence tautomerization in a photoswitchable coordination polymer. Natl Sci Rev 2023; 10:nwad047. [PMID: 37476568 PMCID: PMC10354699 DOI: 10.1093/nsr/nwad047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/05/2022] [Accepted: 12/27/2022] [Indexed: 07/22/2023] Open
Abstract
Organic radicals are widely used as linkers or ligands to synthesize molecular magnetic materials. However, studies regarding the molecular anisotropies of radical-based magnetic materials and their multifunctionalities are rare. Herein, a photoisomerizable diarylethene ligand was used to form {[CoIII(3,5-DTSQ·-)(3,5-DTCat2-)]2(6F-DAE-py2)}·3CH3CN·H2O (o-1·3CH3CN·H2O, 6F-DAE-py2 = 1,2-bis(2-methyl-5-(4-pyridyl)-3-thienyl)perfluorocyclopentene), a valence-tautomeric (VT) coordination polymer. We directly observed dual radicals for a single crystal using high-field/-frequency (∼13.3 T and ∼360 GHz) electron paramagnetic resonance (EPR) spectroscopy along the c-axis, which was further confirmed by angle-dependent Q-band EPR spectroscopy. Moreover, a conductive anomaly close to the VT transition temperature was observed only when probes were attached at the ab plane of the single crystal, indicative of synergy between valence tautomerism and conductivity. Structural anisotropy studies and density functional theory (DFT) calculations revealed that this synergy is due to electron transfer associated with valence tautomerism. This study presents the first example of dual-radical-based molecular anisotropy and charge-transfer-induced conductive anisotropy in a photoswitchable coordination polymer.
Collapse
Affiliation(s)
| | | | | | - Hai-Tao Zhang
- Institute of Inorganic and Applied Chemistry, University of Hamburg, Hamburg22761, Germany
| | - Carmen Herrmann
- Institute of Inorganic and Applied Chemistry, University of Hamburg, Hamburg22761, Germany
| | - Shohei Kumagai
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai980-8578, Japan
| | - Marko Damjanović
- Institute of Inorganic Chemistry, University of Heidelberg, HeidelbergD-69120, Germany
| | - Markus Enders
- Institute of Inorganic Chemistry, University of Heidelberg, HeidelbergD-69120, Germany
| | - Hiroyuki Nojiri
- Institute for Materials Research, Tohoku University, Sendai980-8577, Japan
| | | | - Norihisa Hoshino
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai980-8577, Japan
| | - Tomoyuki Akutagawa
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai980-8577, Japan
| | | |
Collapse
|
19
|
Benner F, La Droitte L, Cador O, Le Guennic B, Demir S. Magnetic hysteresis and large coercivity in bisbenzimidazole radical-bridged dilanthanide complexes. Chem Sci 2023; 14:5577-5592. [PMID: 37265712 PMCID: PMC10231311 DOI: 10.1039/d3sc01562a] [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: 03/25/2023] [Accepted: 04/10/2023] [Indexed: 06/03/2023] Open
Abstract
A judicious combination of radical ligands innate to diffuse spin orbitals with paramagnetic metal ions elicits strong magnetic exchange coupling which leads to properties important for future technologies. This metal-radical approach aids in effective magnetic communication of especially lanthanide ions as their 4f orbitals are contracted and not readily accessible. Notably, a high spin density on the donor atoms of the radical is required for strong coupling. Such molecules are extremely rare owing to high reactivity rendering their isolation challenging. Herein, we present two unprecedented series of bisbenzimidazole-based dilanthanide complexes [(Cp*2Ln)2(μ-Bbim)] (1-Ln = Gd, Tb, Dy, Bbim = 2,2'-bisbenzimidazole) and [K(crypt-222)][(Cp*2Ln)2(μ-Bbim˙)] -(2-Ln = Gd, Tb, Dy), where the latter contains the first Bbim3-˙ radical matched with any paramagnetic metal ion. The magnetic exchange constant for 2-Gd of J = -1.96(2) cm-1 suggests strong antiferromagnetic Gd-radical coupling, whereas the lanthanides in 1-Gd are essentially uncoupled. Ab initio calculations on 2-Tb and 2-Dy uncovered coupling strengths of -4.8 and -1.8 cm-1. 1-Dy features open hysteresis loops with a coercive field of Hc of 0.11 T where the single-molecule magnetism can be attributed to the single-ion effect due to lack of coupling. Excitingly, pairing the effective magnetic coupling with the strong magnetic anisotropy of Dy results in magnetic hysteresis with a blocking temperature TB of 5.5 K and coercive field HC of 0.54 T, ranking 2-Dy as the second best dinuclear single-molecule magnet containing an organic radical bridge. A Bbim4- species is formed electrochemically hinting at the accessibility of Bbim-based redox-active materials.
Collapse
Affiliation(s)
- Florian Benner
- Department of Chemistry, Michigan State University 578 South Shaw Lane East Lansing Michigan 48824 USA
| | - Léo La Droitte
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 F-35000 Rennes France
| | - Olivier Cador
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 F-35000 Rennes France
| | - Boris Le Guennic
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 F-35000 Rennes France
| | - Selvan Demir
- Department of Chemistry, Michigan State University 578 South Shaw Lane East Lansing Michigan 48824 USA
| |
Collapse
|
20
|
Yan H, Wu B, Wei J, Zhang WX. Insight into the Ligand-to-Ligand Charge-Transfer Process in Rare-Earth-Metal Diradical Complexes. Inorg Chem 2023; 62:8052-8057. [PMID: 37184543 DOI: 10.1021/acs.inorgchem.3c00900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
While a ligand-to-ligand charge-transfer (LLCT) process is an important way to understand the interactions between metal-bridged radicals for late-transition-metal complexes, there is little clear and evident observation of the LLCT process for rare-earth-metal complexes. In this work, rare-earth-metal diradical complexes supported by diazabutadiene (DAD) ligands [(DAD)2RE(BH4)] [RE = Yb (1), Sm (2)] were synthesized and studied. The coordination geometries of 1 and 2 are different due to the different ionic radii. Reduction of 1 or 2 generated monoradical complexes, with one of their DAD radical anions being reduced. In all of the complexes, Sm and Yb remain at the 3+ valence state. In their UV-vis spectra, the LLCT transition of 1 could be clearly observed, but complex 2 did not show the same transition. These results could be related to the geometric structures of the complexes as well as exchange coupling between diradicals, thus clearly expanding the model for late-transition-metal-bridged diradicals to rare-earth systems experimentally.
Collapse
Affiliation(s)
- Haihan Yan
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare-earth Materials Chemistry and Applications, and Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Botao Wu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare-earth Materials Chemistry and Applications, and Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Junnian Wei
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare-earth Materials Chemistry and Applications, and Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Wen-Xiong Zhang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare-earth Materials Chemistry and Applications, and Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| |
Collapse
|
21
|
Li HD, Wu SG, Tong ML. Lanthanide-radical single-molecule magnets: current status and future challenges. Chem Commun (Camb) 2023; 59:6159-6170. [PMID: 37129902 DOI: 10.1039/d2cc07042a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In the field of molecular magnetism, the lanthanide-radical (Ln-Rad) method has become one of the most appealing tactics for introducing strong magnetic interactions and has spurred on the booming development of heterospin single-molecule magnets (SMMs). The article is a timely retrospect on the research progress of Ln-Rad heterospin systems and special attention is invested on low dimensional Ln-Rad compounds with SMM behavior, primarily concerning with nitrogen-based radicals, semiquinone and nitroxide radicals. Rational design, molecular structures, magnetic behaviors and magneto-structural correlations are highlighted. Meanwhile, particular attention is focused on the influence of exchange couplings on the dynamic magnetic properties, with the purpose of helping to guide the design of prospective radical-based Ln-SMMs.
Collapse
Affiliation(s)
- Hong-Dao Li
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, P. R. China.
- Department of Chemistry and Chemical Engineering, Taiyuan Institute of Technology, Taiyuan 030008, China
| | - Si-Guo Wu
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, P. R. China.
| | - Ming-Liang Tong
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, P. R. China.
| |
Collapse
|
22
|
Zhang P, Nabi R, Staab JK, Chilton NF, Demir S. Taming Super-Reduced Bi 23- Radicals with Rare Earth Cations. J Am Chem Soc 2023; 145:9152-9163. [PMID: 37043770 PMCID: PMC10141245 DOI: 10.1021/jacs.3c01058] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Here, we report the synthesis of two new sets of dibismuth-bridged rare earth molecules. The first series contains a bridging diamagnetic Bi22- anion, (Cp*2RE)2(μ-η2:η2-Bi2), 1-RE (where Cp* = pentamethylcyclopentadienyl; RE = Gd (1-Gd), Tb (1-Tb), Dy (1-Dy), Y (1-Y)), while the second series comprises the first Bi23- radical-containing complexes for any d- or f-block metal ions, [K(crypt-222)][(Cp*2RE)2(μ-η2:η2-Bi2•)]·2THF (2-RE, RE = Gd (2-Gd), Tb (2-Tb), Dy (2-Dy), Y (2-Y); crypt-222 = 2.2.2-cryptand), which were obtained from one-electron reduction of 1-RE with KC8. The Bi23- radical-bridged terbium and dysprosium congeners, 2-Tb and 2-Dy, are single-molecule magnets with magnetic hysteresis. We investigate the nature of the unprecedented lanthanide-bismuth and bismuth-bismuth bonding and their roles in magnetic communication between paramagnetic metal centers, through single-crystal X-ray diffraction, ultraviolet-visible/near-infrared (UV-vis/NIR) spectroscopy, SQUID magnetometry, DFT and multiconfigurational ab initio calculations. We find a πz* ground SOMO for Bi23-, which has isotropic spin-spin exchange coupling with neighboring metal ions of ca. -20 cm-1; however, the exchange coupling is strongly augmented by orbitally dependent terms in the anisotropic cases of 2-Tb and 2-Dy. As the first examples of p-block radicals beneath the second row bridging any metal ions, these studies have important ramifications for single-molecule magnetism, main group element, rare earth metal, and coordination chemistry at large.
Collapse
Affiliation(s)
- Peng Zhang
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Rizwan Nabi
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Jakob K Staab
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Nicholas F Chilton
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Selvan Demir
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| |
Collapse
|
23
|
Zhang P, Luo QC, Zhu Z, He W, Song N, Lv J, Wang X, Zhai QG, Zheng YZ, Tang J. Radical-Bridged Heterometallic Single-Molecule Magnets Incorporating Four Lanthanoceniums. Angew Chem Int Ed Engl 2023; 62:e202218540. [PMID: 36710242 DOI: 10.1002/anie.202218540] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/25/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023]
Abstract
The syntheses and magnetic properties of organometallic heterometallic compounds [K(THF)6 ]{CoI [(μ3 -HAN)RE2 Cp*4 ]2 } (1-RE) and [K(Crypt)]2 {CoI [(μ3 -HAN)RE2 Cp*4 ]2 } (2-RE) containing hexaazatrinaphthylene radicals (HAN⋅3- ) and four rare earth (RE) ions are reported. 1-RE shows isolable species with ligand-based mixed valency as revealed by cyclic voltammetry (CV) thus leading to the isolation of 2-RE via one-electron chemical reduction. Strong electronic communication in mixed-valency supports stronger overall ferromagnetic behaviors in 2-RE than 1-RE containing Gd and Dy ions. Ac magnetic susceptibility data reveal 1-Dy and 2-Dy both exhibit slow magnetic relaxation. Importantly, larger coercive field was observed in the hysteresis of 2-Dy at 2.0 K, indicating the enhanced SMM behavior compared with 1-Dy. Ligand-based mixed-valency strategy has been used for the first time to improve the magnetic coupling in lanthanide (Ln) SMMs, thus opening up new ways to construct strongly coupled Ln-SMMs.
Collapse
Affiliation(s)
- Peng Zhang
- School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China
| | - Qian-Cheng Luo
- Frontier Institute of Science and Technology (FIST), Xi'an Jiaotong University Xi An Shi, Xi'an, 710054, China
| | - Zhenhua Zhu
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
| | - Wanrong He
- School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China
| | - Nan Song
- School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China
| | - Junting Lv
- School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China
| | - Xuning Wang
- School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China
| | - Quan-Guo Zhai
- School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China
| | - Yan-Zhen Zheng
- Frontier Institute of Science and Technology (FIST), Xi'an Jiaotong University Xi An Shi, Xi'an, 710054, China
| | - Jinkui Tang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
| |
Collapse
|
24
|
Wang J, Sun CY, Zheng Q, Wang DQ, Chen YT, Ju JF, Sun TM, Cui Y, Ding Y, Tang YF. Lanthanide Single-molecule Magnets: Synthetic Strategy, Structures, Properties and Recent Advances. Chem Asian J 2023; 18:e202201297. [PMID: 36802202 DOI: 10.1002/asia.202201297] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/30/2023] [Accepted: 02/20/2023] [Indexed: 02/23/2023]
Abstract
Single-molecule magnets (SMMs) show wide potential applications in the field of ultrahigh-density storage materials, quantum computing, spintronics, and so on. Lanthanide (Ln) SMMs, as an important category of SMMs, open up a promising prospect due to their large magnetic moments and huge magnetic anisotropy. However, the construction of high performance for Ln SMMs remains an enormous challenge. Although remarkable advances are focused on the topic of Ln SMMs, the research on Ln SMMs with different nuclear numbers is still deficient. Therefore, this review summarizes the design strategies for the construction of Ln SMMs, as well as the metal skeleton types. Furthermore, we collect reported Ln SMMs with mononuclearity, dinuclearity, and multinuclearity (three or more Ln spin centers) and the SMM properties including energy barrier (Ueff ) and pre-exponential factor (τ0 ) are described. Finally, Ln SMMs with low-nuclearity SMMs, especially for single-ion magnets (SIMs), are highlighted to understand the correlations between structures and magnetic behavior of the detail SMM properties are described. We expect the review can shed light on the future developments of high-performance Ln SMMs.
Collapse
Affiliation(s)
- Jin Wang
- School of Chemistry and Chemical Engineering, Nantong University, Jiangsu, 226019, P. R. China.,Nantong Key Lab of Intelligent and New Energy Materials, Nantong, Jiangsu 226019, P. R. China
| | - Cheng-Yuan Sun
- School of Chemistry and Chemical Engineering, Nantong University, Jiangsu, 226019, P. R. China
| | - Qi Zheng
- School of Chemistry and Chemical Engineering, Nantong University, Jiangsu, 226019, P. R. China
| | - Dan-Qi Wang
- School of Chemistry and Chemical Engineering, Nantong University, Jiangsu, 226019, P. R. China
| | - Yu-Ting Chen
- School of Chemistry and Chemical Engineering, Nantong University, Jiangsu, 226019, P. R. China
| | - Jian-Feng Ju
- School of Chemistry and Chemical Engineering, Nantong University, Jiangsu, 226019, P. R. China
| | - Tong-Ming Sun
- School of Chemistry and Chemical Engineering, Nantong University, Jiangsu, 226019, P. R. China
| | - Ying Cui
- School of Chemistry and Chemical Engineering, Nantong University, Jiangsu, 226019, P. R. China
| | - Yan Ding
- School of Chemistry and Chemical Engineering, Nantong University, Jiangsu, 226019, P. R. China
| | - Yan-Feng Tang
- School of Chemistry and Chemical Engineering, Nantong University, Jiangsu, 226019, P. R. China.,Nantong Key Lab of Intelligent and New Energy Materials, Nantong, Jiangsu 226019, P. R. China
| |
Collapse
|
25
|
Kotaru S, Kähler S, Alessio M, Krylov AI. Magnetic exchange interactions in binuclear and tetranuclear iron(III) complexes described by spin-flip DFT and Heisenberg effective Hamiltonians. J Comput Chem 2023; 44:367-380. [PMID: 35699152 PMCID: PMC10084445 DOI: 10.1002/jcc.26941] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/07/2022] [Accepted: 04/22/2022] [Indexed: 12/31/2022]
Abstract
Low-energy spectra of single-molecule magnets (SMMs) are often described by Heisenberg Hamiltonians. Within this formalism, exchange interactions between magnetic centers determine the ground-state multiplicity and energy separation between the ground and excited states. In this contribution, we extract exchange coupling constants (J) for a set of iron (III) binuclear and tetranuclear complexes from all-electron calculations using non-collinear spin-flip time-dependent density functional theory (NC-SF-TDDFT). For 12 binuclear complexes with J-values ranging from -6 to -132 cm-1 , our benchmark calculations using the short-range hybrid ωPBEh functional and 6-31G(d,p) basis set agree well with the experimentally derived values (mean absolute error of 4.7 cm-1 ). For the tetranuclear SMMs, the computed J constants are within 6 cm-1 from the experimentally derived values. We explore the range of applicability of the Heisenberg model by analyzing bonding patterns in these Fe(III) complexes using natural orbitals (NO), their occupations, and the number of effectively unpaired electrons. The results illustrate the efficiency of the spin-flip protocol for computing the exchange couplings and the utility of the NO analysis in assessing the validity of effective spin Hamiltonians.
Collapse
Affiliation(s)
- Saikiran Kotaru
- Department of ChemistryUniversity of Southern CaliforniaLos AngelesCalifornia
| | - Sven Kähler
- Department of ChemistryUniversity of Southern CaliforniaLos AngelesCalifornia
| | - Maristella Alessio
- Department of ChemistryUniversity of Southern CaliforniaLos AngelesCalifornia
| | - Anna I. Krylov
- Department of ChemistryUniversity of Southern CaliforniaLos AngelesCalifornia
| |
Collapse
|
26
|
Liao PY, Liu Y, Ruan ZY, Wang HL, Shi CG, Deng W, Wu SG, Jia JH, Tong ML. Magnetic and Luminescent Dual Responses of Photochromic Hexaazamacrocyclic Lanthanide Complexes. Inorg Chem 2023; 62:1075-1085. [PMID: 36625763 DOI: 10.1021/acs.inorgchem.2c02868] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Herein, hexaazamacrocyclic ligand LN6 was employed to construct a series of photochromic rare-earth complexes, [Ln(LN6)(NO3)2](BPh4) [1-Ln, Ln = Dy, Tb, Eu, Gd, Y; LN6 = (3E,5E,10E,12E)-3,6,10,13-tetraaza-1,8(2,6)-dipyridinacyclotetradecaphane-3,5,10,12-tetraene]. The behavior of photogenerated radicals of hexaazamacrocyclic ligands was revealed for the first time. Upon 365 nm light irradiation, complexes 1-Ln exhibit photochromic behavior induced by photogenerated radicals according to EPR and UV-vis analyses. Static and dynamic magnetic studies of 1-Dy and irradiated product 1-Dy* indicate weak ferromagnetic interactions among DyIII ions and photogenerated LN6 radicals, as well as slow magnetization relaxation behavior under a 2 kOe applied field. Further fitting analyses show that the magnetization relaxation in 1-Dy* is markedly different from 1-Dy. Time-dependent fluorescence measurements reveal the characteristic luminescence quenching dynamics of lanthanide in the photochromic process. Especially for irradiated product 1-Eu*, the luminescence is almost completely quenched within 5 min with a quenching efficiency of 98.4%. The results reported here provide a prospect for the design of radical-induced photochromic lanthanide single-molecule magnets and will promote the further development of multiresponsive photomagnetic materials.
Collapse
Affiliation(s)
- Pei-Yu Liao
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Yang Liu
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Ze-Yu Ruan
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Hai-Ling Wang
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Chen-Guang Shi
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Wei Deng
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Si-Guo Wu
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Jian-Hua Jia
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Ming-Liang Tong
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| |
Collapse
|
27
|
Mahieu N, Piątkowski J, Simler T, Nocton G. Back to the future of organolanthanide chemistry. Chem Sci 2023; 14:443-457. [PMID: 36741512 PMCID: PMC9848160 DOI: 10.1039/d2sc05976b] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 11/29/2022] [Indexed: 12/02/2022] Open
Abstract
At the dawn of the development of structural organometallic chemistry, soon after the discovery of ferrocene, the description of the LnCp3 complexes, featuring large and mostly trivalent lanthanide ions, was rather original and sparked curiosity. Yet, the interest in these new architectures rapidly dwindled due to the electrostatic nature of the bonding between π-aromatic ligands and 4f-elements. Almost 70 years later, it is interesting to focus on how the discipline has evolved in various directions with the reports of multiple catalytic reactivities, remarkable potential in small molecule activation, and the development of rich redox chemistry. Aside from chemical reactivity, a better understanding of their singular electronic nature - not precisely as simplistic as anticipated - has been crucial for developing tailored compounds with adapted magnetic anisotropy or high fluorescence properties that have witnessed significant popularity in recent years. Future developments shall greatly benefit from the detailed reactivity, structural and physical chemistry studies, particularly in photochemistry, electro- or photoelectrocatalysis of inert small molecules, and manipulating the spins' coherence in quantum technology.
Collapse
Affiliation(s)
- Nolwenn Mahieu
- LCM, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay91120 PalaiseauFrance
| | - Jakub Piątkowski
- LCM, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay91120 PalaiseauFrance
| | - Thomas Simler
- LCM, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay91120 PalaiseauFrance
| | - Grégory Nocton
- LCM, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay91120 PalaiseauFrance
| |
Collapse
|
28
|
Maurice R, Mallah T, Guihéry N. Magnetism in Binuclear Compounds: Theoretical Insights. TOP ORGANOMETAL CHEM 2023. [DOI: 10.1007/3418_2022_78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
29
|
Shao D, Sahu PP, Tang WJ, Zhang YL, Zhou Y, Xu FX, Wei XQ, Tian Z, Singh SK, Wang XY. A single-ion magnet building block strategy toward Dy 2 single-molecule magnets with enhanced magnetic performance. Dalton Trans 2022; 51:18610-18621. [PMID: 36448324 DOI: 10.1039/d2dt03046b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A molecular dysprosium(III) complex [Dy(DClQ)3(H2O)2] (1) was used as a building unit for the construction of lanthanide SMMs, leading to the isolation of two dinuclear Dy(III) complexes, namely [Dy2(DClQ)6(MeOH)2] (2) and [Dy2(DClQ)6(bpmo)2]·6MeCN (3) (DClQ = 5,7-dichloro-8-hydroxyquinoline, bpmo = 4,4'-dipyridine-oxide). Structural analyses revealed the same N3O5 coordination environment of the Dy(III) centers with a distorted biaugmented trigonal prism (C2V symmetry) and triangular dodecahedron (D2d symmetry) for 2 and 3, respectively. Magnetic studies revealed the presence of ferromagnetic and weak antiferromagnetic exchange interactions between the Dy3+ centers in 2 and 3, respectively. Interestingly, slow relaxation of magnetization at zero fields was evidenced with an Ueff of 51.4 K and 159.0 K for complexes 2 and 3, respectively. The detailed analysis of relaxation dynamics discloses that the Orbach process is dominant for 2 whereas Raman and QTM play an important role in 3. Theoretical calculations were carried out to provide insight into the magnetic exchange interactions and relaxation dynamics for the complexes. Due to a single-ion magnet (SIM) of 1, the foregoing results demonstrate a SIM modular synthetic route for the preparation of dinuclear lanthanide SMMs.
Collapse
Affiliation(s)
- Dong Shao
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China.,State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China.
| | - Prem Prakash Sahu
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi-502285, Sangareddy, Telangana, India.
| | - Wan-Jie Tang
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China
| | - Yang-Lu Zhang
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China
| | - Yue Zhou
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China
| | - Fang-Xue Xu
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China.
| | - Xiao-Qin Wei
- Department of Material Science and Engineering, Shanxi Province Collaborative Innovation Center for Light Materials Modification and Application, Jinzhong University, Jinzhong, 030619, P. R. China
| | - Zhengfang Tian
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China
| | - Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi-502285, Sangareddy, Telangana, India.
| | - Xin-Yi Wang
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China.
| |
Collapse
|
30
|
Xia CC, Ji WJ, Zhang XY, Miao H, Zhang YQ, Wang XY. Syntheses, structures, and magnetic properties of the lanthanide complexes of imidazole-substituted nitronyl nitroxide biradicals. Dalton Trans 2022; 51:12362-12372. [PMID: 35904351 DOI: 10.1039/d2dt01652d] [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
Two new bis-bidentate imidazole-substituted nitronyl nitroxide biradicals, BNITIm-C2 (BNITIm-C2 = 1,1'-(1,2-ethanediyl)bis(1H-imidazole-2-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxy-3-oxide)) and BNITIm-C4 (BNITIm-C4 = 1,1'-(1,4-butanediyl)bis(1H-imidazole-2-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxy-3-oxide)), and two series of lanthanide complexes, namely [(BNITIm-C2)Ln(NO3)3](MeOH) (Ln = Gd (1Gd) and Tb (2Tb)), (BNITIm-C2)Dy(NO3)3 (3Dy) and (BNITIm-C4)[Ln(hfac)3]2(C7H8)2 (Ln = Gd (4Gd), Tb (5Tb) and Dy (6Dy), hfac = hexafluoroacetylacetonate), have been prepared and characterized structurally and magnetically. Single crystal X-ray crystallographic analyses revealed that complexes 1Gd-3Dy exhibit 1D chain structures where the Ln(NO3)3 units are bridged by the BNITIm-C2 bis-bidentate biradical, while complexes 4Gd-6Dy exhibit binuclear structures with two Ln(hfac)3 units bridged by the BNITIm-C4 biradical. The bulky hfac anions prohibit the further coordination of LnIII to another NIT ligand and the formation of a similar 1D chain structure. Due to the very long intra- and intermolecular distances of the spin centers, complexes 1Gd-3Dy can be magnetically regarded as an isolated 2p-4f-2p tri-spin system while complex 4Gd-6Dy can be regarded as an isolated 2p-4f bi-spin system. Magnetic analyses on the two GdIII compounds revealed the ferromagnetic GdIII-NIT interactions and antiferromagnetic NIT-NIT interactions through the GdIII ion in 1Gd. Alternating-current (ac) magnetic susceptibility investigations revealed that complex 5Tb exhibits the typical SMM behavior under a zero dc field while complex 6Dy was proved to be a field-induced SMM. Ab initio calculations were performed on complexes 2Tb and 5Tb to understand their magnetic anisotropy together with their different magnetic dynamics.
Collapse
Affiliation(s)
- Cheng-Cai Xia
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
| | - Wen-Jie Ji
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
| | - Xin-Yu Zhang
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
| | - Hao Miao
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, China.
| | - Xin-Yi Wang
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
| |
Collapse
|
31
|
Nguyen GT, Ungur L. The Role of Radical Bridges in Polynuclear Single‐Molecule Magnets. Chemistry 2022; 28:e202200227. [DOI: 10.1002/chem.202200227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Giang Truong Nguyen
- Department of Chemistry Faculty of Science National University of Singapore Block S8 Level 3, 3 Science Drive 3 Singapore Singapore 117543
| | - Liviu Ungur
- Department of Chemistry Faculty of Science National University of Singapore Block S8 Level 3, 3 Science Drive 3 Singapore Singapore 117543
| |
Collapse
|
32
|
|
33
|
Pugliese ER, Benner F, Castellanos E, Delano F, Demir S. Heteroleptic Rare-Earth Tris(metallocenes) Containing a Dibenzocyclooctatetraene Dianion. Inorg Chem 2022; 61:2444-2454. [PMID: 35042339 DOI: 10.1021/acs.inorgchem.1c03230] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Isolable heteroleptic tris(metallocenes) containing five-membered and larger rings remain extremely scarce. The utilization of tripositive rare-earth-metal ions with ionic radii >1 Å allowed access to unprecedented and sterically congested dibenzocyclooctatetraenyl (dbCOT) metallocenes, [K(crypt-222)][Cptet2RE(η2-dbCOT)] (RE = Y (1), Dy (2); Cptet = tetramethylcyclopentadienyl), through a salt metathesis reaction involving Cptet2RE(BPh4) and the potassium salt of the dbCOT dianion. The solid-state structures were investigated by single-crystal X-ray diffraction, magnetometry, and IR spectroscopy and provided evidence for the first crystallographically characterized (dbCOT)2- anion in a complex containing d- or f-block metals. Remarkably, the (Cptet)- ligands force a distortion from planarity within the (dbCOT)2- moiety, engendering a rare η2-bonding motif, as opposed to the classical η8 conformation observed in complexes bearing a (COT)2- ion. The η2 coordination mode was proven crystallographically between 100 and 298 K and computationally (DFT and NBO). Furthermore, nucleus independent chemical shift (NICS) calculations uncovered significant ring current within the dbCOT ligand. The solution-state properties of 1 and 2 were analyzed via cyclic voltammetry, NMR, and UV-vis spectroscopy. Cyclic voltammograms of 1 and 2 exhibit a quasi-reversible feature indicating the accessibility of complexes with dbCOT in two oxidation states (dbCOT2-/3-•). Importantly, the dysprosium congener, 2, is a zero-field single-molecule magnet (SMM).
Collapse
Affiliation(s)
- Elizabeth R Pugliese
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48823, United States
| | - Florian Benner
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48823, United States
| | - Ernesto Castellanos
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48823, United States
| | - Francis Delano
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48823, United States
| | - Selvan Demir
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48823, United States
| |
Collapse
|
34
|
Three hetero-tri-spin Ln2CuNIT complexes based on a 1-methyl-3-pyrazole nitronyl nitroxide radical: Syntheses, structures and magnetic properties. Polyhedron 2022. [DOI: 10.1016/j.poly.2021.115594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
35
|
Shao D, Moorthy S, Zhou Y, Wu ST, Zhu JY, Yang J, Wu D, Tian Z, Singh SKK. Field-induced slow magnetic relaxation behaviours in binuclear cobalt(II) metallocycle and exchange-coupled cluster. Dalton Trans 2022; 51:9357-9368. [DOI: 10.1039/d2dt01620f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Precise control of structures and magnetic properties of a molecular material constitutes an important challenge to realize the tailor-made magnetic function. Herein, we reported that the ligand-directed coordination self-assembly of...
Collapse
|
36
|
Zhu Z, Tang J. Metal–metal bond in lanthanide single-molecule magnets. Chem Soc Rev 2022; 51:9469-9481. [DOI: 10.1039/d2cs00516f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This review surveys recent critical advances in lanthanide SMMs, highlighting the influences of metal–metal bonds on the magnetization dynamics.
Collapse
Affiliation(s)
- Zhenhua Zhu
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jinkui Tang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
| |
Collapse
|
37
|
Corner SC, Goodwin CAP, Ortu F, Evans P, Zhang H, Gransbury GK, Whitehead GFS, Mills DP. Synthesis of heteroleptic yttrium and dysprosium 1,2,4-tris(trimethylsilyl)cyclopentadienyl complexes. Aust J Chem 2022. [DOI: 10.1071/ch21314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
38
|
Castellanos E, Benner F, Demir S. Taming salophen in rare earth metallocene chemistry. Inorg Chem Front 2022. [DOI: 10.1039/d1qi01331a] [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
An unprecedented series of salophen-bridged rare earth metallocenes, (Cp*2RE)2(μ-tBusalophen) (RE = Gd, Dy, and Y), has been crystallized. The solid and solution states have been unambiguously characterized by magnetic, spectroscopic and DFT methods.
Collapse
Affiliation(s)
- Ernesto Castellanos
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan, 48824, USA
| | - Florian Benner
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan, 48824, USA
| | - Selvan Demir
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan, 48824, USA
| |
Collapse
|
39
|
Dinuclear dysprosium(III) complex derived from a multidentate bis-hydrazone Schiff base ligand: Synthesis, crystal structure and magnetic properties. Polyhedron 2022. [DOI: 10.1016/j.poly.2021.115603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
40
|
Benner F, Demir S. Isolation of the elusive bisbenzimidazole Bbim 3−˙ radical anion and its employment in a metal complex. Chem Sci 2022; 13:5818-5829. [PMID: 35685798 PMCID: PMC9132035 DOI: 10.1039/d1sc07245e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 04/05/2022] [Indexed: 11/28/2022] Open
Abstract
The discovery of singular organic radical ligands is a formidable challenge due to high reactivity arising from the unpaired electron. Matching radical ligands with metal ions to engender magnetic coupling is crucial for eliciting preeminent physical properties such as conductivity and magnetism that are crucial for future technologies. The metal-radical approach is especially important for the lanthanide ions exhibiting deeply buried 4f-orbitals. The radicals must possess a high spin density on the donor atoms to promote strong coupling. Combining diamagnetic 89Y (I = 1/2) with organic radicals allows for invaluable insight into the electronic structure and spin-density distribution. This approach is hitherto underutilized, possibly owing to the challenging synthesis and purification of such molecules. Herein, evidence of an unprecedented bisbenzimidazole radical anion (Bbim3−˙) along with its metalation in the form of an yttrium complex, [K(crypt-222)][(Cp*2Y)2(μ-Bbim˙)] is provided. Access of Bbim3−˙ was feasible through double-coordination to the Lewis acidic metal ion and subsequent one-electron reduction, which is remarkable as Bbim2− was explicitly stated to be redox-inactive in closed-shell complexes. Two molecules containing Bbim2− (1) and Bbim3−˙ (2), respectively, were thoroughly investigated by X-ray crystallography, NMR and UV/Vis spectroscopy. Electrochemical studies unfolded a quasi-reversible feature and emphasize the role of the metal centre for the Bbim redox-activity as neither the free ligand nor the Bbim2− complex led to analogous CV results. Excitingly, a strong delocalization of the electron density through the Bbim3−˙ ligand was revealed via temperature-dependent EPR spectroscopy and confirmed through DFT calculations and magnetometry, rendering Bbim3−˙ an ideal candidate for single-molecule magnet design. The long sought-after bisbenzimidazole radical was isolated through complexation to two rare earth metallocenes followed by reduction, and analysed through crystallography, VT EPR spectroscopy, electrochemistry, magnetometry, and DFT computations.![]()
Collapse
Affiliation(s)
- Florian Benner
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, USA
| | - Selvan Demir
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, USA
| |
Collapse
|
41
|
Modder DK, Batov MS, Rajeshkumar T, Sienkiewicz A, Zivkovic I, Scopelliti R, Maron L, Mazzanti M. Assembling Diuranium Complexes in Different States of Charge with a Bridging Redox-Active Ligand. Chem Sci 2022; 13:11294-11303. [PMID: 36320571 PMCID: PMC9533398 DOI: 10.1039/d2sc03592h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 08/30/2022] [Indexed: 11/21/2022] Open
Abstract
Radical-bridged diuranium complexes are desirable for their potential high exchange coupling and single molecule magnet (SMM) behavior, but remain rare. Here we report for the first time radical-bridged diuranium(iv) and diuranium(iii) complexes. Reaction of [U{N(SiMe3)2}3] with 2,2′-bipyrimidine (bpym) resulted in the formation of the bpym-bridged diuranium(iv) complex [{((Me3Si)2N)3UIV}2(μ-bpym2−)], 1. Reduction with 1 equiv. KC8 reduces the complex, affording [K(2.2.2-cryptand)][{((Me3Si)2N)3U}2(μ-bpym)], 2, which is best described as a radical-bridged UIII–bpym˙−–UIII complex. Further reduction of 1 with 2 equiv. KC8, affords [K(2.2.2-cryptand)]2[{((Me3Si)2N)3UIII}2(μ-bpym2−)], 3. Addition of AgBPh4 to complex 1 resulted in the oxidation of the ligand, yielding the radical-bridged complex [{((Me3Si)2N)3UIV}2(μ-bpym˙−)][BPh4], 4. X-ray crystallography, electrochemistry, susceptibility data, EPR and DFT/CASSCF calculations are in line with their assignments. In complexes 2 and 4 the presence of the radical-bridge leads to slow magnetic relaxation. Convenient routes to dinuclear complexes of uranium where two uranium centers are bridged by the redox-active ligand bpym were identified resulting in unique and stable radical-bridged dimetallic complexes of U(iii) and U(iv) showing SMM behaviour.![]()
Collapse
Affiliation(s)
- Dieuwertje K Modder
- Group of Coordination Chemistry, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Mikhail S Batov
- Group of Coordination Chemistry, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Thayalan Rajeshkumar
- Laboratoire de Physique et Chimie des Nano-objets, Institut National des Sciences Appliquées Cedex 4 31077 Toulouse France
| | - Andrzej Sienkiewicz
- Laboratory for Quantum Magnetism, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
- ADSresonances Sàrl Route de Genève 60B 1028 Préverenges Switzerland
| | - Ivica Zivkovic
- Laboratory for Quantum Magnetism, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Rosario Scopelliti
- Group of Coordination Chemistry, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Laurent Maron
- Laboratoire de Physique et Chimie des Nano-objets, Institut National des Sciences Appliquées Cedex 4 31077 Toulouse France
| | - Marinella Mazzanti
- Group of Coordination Chemistry, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| |
Collapse
|
42
|
Chen YC, Tong ML. Single-Molecule Magnets beyond a Single Lanthanide Ion: The Art of Coupling. Chem Sci 2022; 13:8716-8726. [PMID: 35975153 PMCID: PMC9350631 DOI: 10.1039/d2sc01532c] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/23/2022] [Indexed: 11/22/2022] Open
Abstract
The promising future of storing and processing quantized information at the molecular level has been attracting the study of Single-Molecule Magnets (SMMs) for almost three decades. Although some recent breakthroughs are mainly about the SMMs containing only one lanthanide ion, we believe SMMs can tell a much deeper story than the single-ion anisotropy. Here in this Perspective, we will try to draw a unified picture of SMMs as a delicately coupled spin system between multiple spin centres. The hierarchical couplings will be presented step-by-step, from the intra-atomic hyperfine coupling, to the direct and indirect intra-molecular couplings with neighbouring spin centres, and all the way to the inter-molecular and spin–phonon couplings. Along with the discussions on their distinctive impacts on the energy level structures and thus magnetic behaviours, a promising big picture for further studies is proposed, encouraging the multifaceted developments of molecular magnetism and beyond. In this Perspective, we draw a unified picture for single-molecule magnets as delicately coupled spin systems, discuss the hierarchical couplings (from intra-atomic to inter-molecular) and their distinctive impacts on the magnetic behaviours.![]()
Collapse
Affiliation(s)
- Yan-Cong Chen
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University Guangzhou 510006 P. R. China
| | - Ming-Liang Tong
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University Guangzhou 510006 P. R. China
| |
Collapse
|
43
|
Leng JD, Hua QY, Liu WT, Tao ZX, Tan NW, Wang YF, Lin WQ. Slow magnetic relaxation of mononuclear complexes based on uncommon Kramers lanthanide ions CeIII, SmIII and YbIII. Dalton Trans 2022; 51:12661-12669. [DOI: 10.1039/d2dt00766e] [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 uncommon Kramers ions CeIII, SmIII and YbIII, complexes [Ce(dppbO2)2Cl3] (1, dppbO2 = 1,2-bis(diphenylphosphino)benzene dioxide), [Sm(dppbO2)2Cl3] (2) and [Yb(dppbO2)2Cl2]Cl (3) toward single-ion magnets were obtained and fully characterized. Complexes...
Collapse
|
44
|
Delano Iv F, Castellanos E, McCracken J, Demir S. A rare earth metallocene containing a 2,2'-azopyridyl radical anion. Chem Sci 2021; 12:15219-15228. [PMID: 34976342 PMCID: PMC8634996 DOI: 10.1039/d1sc04285h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/12/2021] [Indexed: 11/21/2022] Open
Abstract
Introducing spin onto organic ligands that are coordinated to rare earth metal ions allows direct exchange with metal spin centres. This is particularly relevant for the deeply buried 4f-orbitals of the lanthanide ions that can give rise to unparalleled magnetic properties. For efficacy of exchange coupling, the donor atoms of the radical ligand require high-spin density. Such molecules are extremely rare owing to their reactive nature that renders isolation and purification difficult. Here, we demonstrate that a 2,2′-azopyridyl (abpy) radical (S = 1/2) bound to the rare earth metal yttrium can be realized. This molecule represents the first rare earth metal complex containing an abpy radical and is unambigously characterized by X-ray crystallography, NMR, UV-Vis-NIR, and IR spectroscopy. In addition, the most stable isotope 89Y with a natural abundance of 100% and a nuclear spin of ½ allows an in-depth analysis of the yttrium–radical complex via EPR and HYSCORE spectroscopy. Further insight into the electronic ground state of the radical azobispyridine-coordinated metal complex was realized through unrestricted DFT calculations, which suggests that the unpaired spin density of the SOMO is heavily localized on the azo and pyridyl nitrogen atoms. The experimental results are supported by NBO calculations and give a comprehensive picture of the spin density of the azopyridyl ancillary ligand. This unexplored azopyridyl radical anion in heavy element chemistry bears crucial implications for the design of molecule-based magnets particularly comprising anisotropic lanthanide ions. Unambiguous characterization of the first 2,2′-azobispyridine radical-containing rare earth metal complex through X-ray crystallography, DFT computations, EPR and HYSCORE spectroscopy.![]()
Collapse
Affiliation(s)
- Francis Delano Iv
- Department of Chemistry, Michigan State University 578 South Shaw Lane East Lansing Michigan 48824 USA
| | - Ernesto Castellanos
- Department of Chemistry, Michigan State University 578 South Shaw Lane East Lansing Michigan 48824 USA
| | - John McCracken
- Department of Chemistry, Michigan State University 578 South Shaw Lane East Lansing Michigan 48824 USA
| | - Selvan Demir
- Department of Chemistry, Michigan State University 578 South Shaw Lane East Lansing Michigan 48824 USA
| |
Collapse
|
45
|
Gupta SK, Dey S, Rajeshkumar T, Rajaraman G, Murugavel R. Deciphering the Role of Anions and Secondary Coordination Sphere in Tuning Anisotropy in Dy(III) Air-Stable D 5h SIMs*. Chemistry 2021; 28:e202103585. [PMID: 34788493 DOI: 10.1002/chem.202103585] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Indexed: 01/05/2023]
Abstract
Precise control of the crystal field and symmetry around the paramagnetic spin centre has recently facilitated the engineering of high-temperature single-ion magnets (SIMs), the smallest possible units for future spin-based devices. In the present work, we report a series of air-stable seven coordinate Dy(III) SIMs {[L2 Dy(H2 O)5 ][X]3 ⋅L2 ⋅n(H2 O), n = 0, X = Cl (1), n=1, X = Br (2), I (3)} possessing pseudo-D5h symmetry or pentagonal bipyramidal coordination geometry with high anisotropy energy barrier (Ueff ) and blocking temperature (TB ). While the strong axial coordination from the sterically encumbered phosphonamide, t BuPO(NHi Pr)2 (L), increases the overall anisotropy of the system, the presence of high symmetry significantly quenches quantum tunnelling of magnetization, which is the prominent deactivating factor encountered in SIMs. The energy barrier (Ueff ) and the blocking temperature (TB ) decrease in the order 3>2>1 with the change of anions from larger iodide to smaller strongly hydrogen-bonded chloride in the secondary coordination sphere, albeit the local coordination geometry and the symmetry around the Dy(III) display only slight deviations. Ab initio CASSCF/RASSI-SO/SINGLE_ANISO calculations provide deeper insights into the dynamics of magnetic relaxation in addition to the role of the secondary coordination sphere in modulating the anisotropy of the D5h systems, using diverse models. Thus, in addition to the importance of the crystal field and the symmetry to obtain high-temperature SIMs, this study also probes the significance of the secondary coordination sphere that can be tailored to accomplish novel SIMs.
Collapse
Affiliation(s)
- Sandeep K Gupta
- Department of Chemistry, Indian Institute of Technology Bombay Powai, Mumbai, 400 076, India
| | - Sourav Dey
- Department of Chemistry, Indian Institute of Technology Bombay Powai, Mumbai, 400 076, India
| | - Thayalan Rajeshkumar
- Department of Chemistry, Indian Institute of Technology Bombay Powai, Mumbai, 400 076, India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay Powai, Mumbai, 400 076, India
| | - Ramaswamy Murugavel
- Department of Chemistry, Indian Institute of Technology Bombay Powai, Mumbai, 400 076, India
| |
Collapse
|
46
|
Hu JJ, Peng Y, Liu SJ, Wen HR. Recent advances in lanthanide coordination polymers and clusters with magnetocaloric effect or single-molecule magnet behavior. Dalton Trans 2021; 50:15473-15487. [PMID: 34668916 DOI: 10.1039/d1dt02797b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular magnetorefrigerant materials for low-temperature magnetic refrigeration and single-molecule magnets for high-density information storage and quantum computing have received extensive attention from chemists and magnetic experts. Lanthanide ions with unique magnetic properties have always been considered as ideal candidates for the construction of such materials. This frontier article focuses on GdIII-based molecular magnetorefrigerants and lanthanide-based single-molecule magnets and highlights the most significant advances.
Collapse
Affiliation(s)
- Jun-Jie Hu
- School of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi Province, P.R. China.
| | - Yan Peng
- School of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi Province, P.R. China.
| | - Sui-Jun Liu
- School of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi Province, P.R. China.
| | - He-Rui Wen
- School of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi Province, P.R. China.
| |
Collapse
|
47
|
Dey S, Rajaraman G. Attaining record-high magnetic exchange, magnetic anisotropy and blocking barriers in dilanthanofullerenes. Chem Sci 2021; 12:14207-14216. [PMID: 34760206 PMCID: PMC8565386 DOI: 10.1039/d1sc03925c] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 10/06/2021] [Indexed: 11/29/2022] Open
Abstract
While the blocking barrier (U eff) and blocking temperature (T B) for "Dysprocenium" SIMs have been increased beyond liquid N2 temperature, device fabrication of these molecules remains a challenge as low-coordinate Ln3+ complexes are very unstable. Encapsulating the lanthanide ion inside a cage such as a fullerene (called endohedral metallofullerene or EMF) opens up a new avenue leading to several Ln@EMF SMMs. The ab initio CASSCF calculations play a pivotal role in identifying target metal ions and suitable cages in this area. Encouraged by our earlier prediction on Ln2@C79N, which was verified by experiments, here we have undertaken a search to enhance the exchange coupling in this class of molecules beyond the highest reported value. Using DFT and ab initio calculations, we have studied a series of Gd2@C2n (30 ≤ 2n ≤ 80), where an antiferromagnetic J Gd⋯Gd of -43 cm-1 was found for a stable Gd2@C38-D 3h cage. This extremely large and exceptionally rare 4f⋯4f interaction results from a direct overlap of 4f orbitals due to the confinement effect. In larger cages such as Gd2@C60 and Gd2@C80, the formation of two centre-one-electron (2c-1e-) Gd-Gd bonds is perceived. This results in a radical formation in the fullerene cage leading to its instability. To avoid this, we have studied heterofullerenes where one of the carbon atoms is replaced by a nitrogen atom. Specifically, we have studied Ln2@C59N and Ln2@C79N, where strong delocalisation of the electron yields a mixed valence-like behaviour. This suggests a double-exchange (B) is operational, and CASSCF calculations yield a B value of 434.8 cm-1 and resultant J Gd-rad of 869.5 cm-1 for the Gd2@C59N complex. These parameters are found to be two times larger than the world-record J reported for Gd2@C79N. Further ab initio calculations reveal an unprecedented U cal of 1183 and 1501 cm-1 for Dy2@C59N and Tb2@C59N, respectively. Thus, this study offers strong exchange coupling as criteria for new generation SMMs as the existing idea of enhancing the blocking barrier via crystal field modulation has reached its saturation point.
Collapse
Affiliation(s)
- Sourav Dey
- Department of Chemistry, Indian Institute of Technology Bombay Powai Mumbai 400076 India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay Powai Mumbai 400076 India
| |
Collapse
|
48
|
Mavragani N, Errulat D, Gálico DA, Kitos AA, Mansikkamäki A, Murugesu M. Radical‐Bridged Ln
4
Metallocene Complexes with Strong Magnetic Coupling and a Large Coercive Field. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202110813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Niki Mavragani
- Department of Chemistry and Biomolecular Sciences University of Ottawa 10 Marie Curie Ottawa Ontario K1N 6N5 Canada
| | - Dylan Errulat
- Department of Chemistry and Biomolecular Sciences University of Ottawa 10 Marie Curie Ottawa Ontario K1N 6N5 Canada
| | - Diogo A. Gálico
- Department of Chemistry and Biomolecular Sciences University of Ottawa 10 Marie Curie Ottawa Ontario K1N 6N5 Canada
| | - Alexandros A. Kitos
- Department of Chemistry and Biomolecular Sciences University of Ottawa 10 Marie Curie Ottawa Ontario K1N 6N5 Canada
| | | | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences University of Ottawa 10 Marie Curie Ottawa Ontario K1N 6N5 Canada
| |
Collapse
|
49
|
Mavragani N, Errulat D, Gálico DA, Kitos AA, Mansikkamäki A, Murugesu M. Radical-Bridged Ln 4 Metallocene Complexes with Strong Magnetic Coupling and a Large Coercive Field. Angew Chem Int Ed Engl 2021; 60:24206-24213. [PMID: 34427984 DOI: 10.1002/anie.202110813] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Indexed: 11/05/2022]
Abstract
Inducing magnetic coupling between 4f elements is an ongoing challenge. To overcome this formidable difficulty, we incorporate highly delocalized tetrazinyl radicals, which strongly couple with f-block metallocenes to form discrete tetranuclear complexes. Synthesis, structure, and magnetic properties of two tetranuclear [(Cp*2 Ln)4 (tz. )4 ]⋅3(C6 H6 ) (Cp*=pentamethylcyclopentadienyl; tz=1,2,4,5-tetrazine; Ln=Dy, Gd) complexes are reported. An in-depth examination of their magnetic properties through magnetic susceptibility measurements as well as computational studies support a highly sought-after radical-induced "giant-spin" model. Strong exchange interactions between the LnIII ions and tz. radicals lead to a strong magnet-like behaviour in this molecular magnet with a large coercive field of 30 kOe.
Collapse
Affiliation(s)
- Niki Mavragani
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| | - Dylan Errulat
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| | - Diogo A Gálico
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| | - Alexandros A Kitos
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| | | | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| |
Collapse
|
50
|
Low-Coordinate Dinuclear Dysprosium(III) Single Molecule Magnets Utilizing LiCl as Bridging Moieties and Tris(amido)amine as Blocking Ligands. MAGNETOCHEMISTRY 2021. [DOI: 10.3390/magnetochemistry7090125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A low-coordinate dinuclear dysprosium complex {[Dy(N3N)(THF)][LiCl(THF)]}2 (Dy2) with a double bridging ‘LiCl’ moiety and tris(amido)amine (N3N)3− anions as a blocking ligand is synthesized and characterized structurally and magnetically. Thanks to the use of the chelating blocking ligand (N3N)3− equipped with large steric –SiMe3 groups, the coordination sphere of both DyIII ions is restricted to only six donor atoms. The three amido nitrogen atoms determine the orientation of the easy magnetization axes of both DyIII centers. Consequently, Dy2 shows slow magnetic relaxation typical for single molecule magnets (SMMs). However, the effective energy barrier for magnetization reversal determined from the AC magnetic susceptibility measurements is much lower than the separation between the ground and the first excited Kramers doublet based on the CASSCF ab initio calculations. In order to better understand the possible influence of the anticipated intramolecular magnetic interactions in this dinuclear molecule, its GdIII-analog {[Gd(N3N)(THF)][LiCl(THF)]}2 (Gd2) is also synthesized and studied magnetically. Detailed magnetic measurements reveal very weak antiferromagnetic interactions in Gd2. This in turn suggests similar antiferromagnetic interactions in Dy2, which might be responsible for its peculiar SMM behavior and the absence of the magnetic hysteresis loop.
Collapse
|