1
|
Moseley DH, Liu Z, Bone AN, Stavretis SE, Singh SK, Atanasov M, Lu Z, Ozerov M, Thirunavukkuarasu K, Cheng Y, Daemen LL, Lubert-Perquel D, Smirnov D, Neese F, Ramirez-Cuesta AJ, Hill S, Dunbar KR, Xue ZL. Comprehensive Studies of Magnetic Transitions and Spin-Phonon Couplings in the Tetrahedral Cobalt Complex Co(AsPh 3) 2I 2. Inorg Chem 2022; 61:17123-17136. [PMID: 36264658 DOI: 10.1021/acs.inorgchem.2c02604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A combination of inelastic neutron scattering (INS), far-IR magneto-spectroscopy (FIRMS), and Raman magneto-spectroscopy (RaMS) has been used to comprehensively probe magnetic excitations in Co(AsPh3)2I2 (1), a reported single-molecule magnet (SMM). With applied field, the magnetic zero-field splitting (ZFS) peak (2D') shifts to higher energies in each spectroscopy. INS placed the ZFS peak at 54 cm-1, as revealed by both variable-temperature (VT) and variable-magnetic-field data, giving results that agree well with those from both far-IR and Raman studies. Both FIRMS and RaMS also reveal the presence of multiple spin-phonon couplings as avoided crossings with neighboring phonons. Here, phonons refer to both intramolecular and lattice vibrations. The results constitute a rare case in which the spin-phonon couplings are observed with both Raman-active (g modes) and far-IR-active phonons (u modes; space group P21/c, no. 14, Z = 4 for 1). These couplings are fit using a simple avoided crossing model with coupling constants of ca. 1-2 cm-1. The combined spectroscopies accurately determine the magnetic excited level and the interaction of the magnetic excitation with phonon modes. Density functional theory (DFT) phonon calculations compare well with INS, allowing for the assignment of the modes and their symmetries. Electronic calculations elucidate the nature of ZFS in the complex. Features of different techniques to determine ZFS and other spin-Hamiltonian parameters in transition-metal complexes are summarized.
Collapse
Affiliation(s)
- Duncan H Moseley
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
| | - Zhiming Liu
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
| | - Alexandria N Bone
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
| | - Shelby E Stavretis
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
| | - Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, 502285Sangareddy, Telangana, India
| | - Mihail Atanasov
- Max Planck Institute for Coal Research, Kaiser-Wilhelm-Platz 1, D-45470Mülheim an der Ruhr, Germany.,Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113Sofia, Bulgaria
| | - Zhengguang Lu
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida32310, United States
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida32310, United States
| | | | - Yongqiang Cheng
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Luke L Daemen
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Daphné Lubert-Perquel
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida32310, United States
| | - Dmitry Smirnov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida32310, United States
| | - Frank Neese
- Max Planck Institute for Coal Research, Kaiser-Wilhelm-Platz 1, D-45470Mülheim an der Ruhr, Germany
| | - A J Ramirez-Cuesta
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Stephen Hill
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida32310, United States.,Department of Physics, Florida State University, Tallahassee, Florida32306, United States
| | - Kim R Dunbar
- Department of Chemistry, Texas A&M University, College Station, Texas77843, United States
| | - Zi-Ling Xue
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
| |
Collapse
|
2
|
Polarized Neutron Diffraction: An Excellent Tool to Evidence the Magnetic Anisotropy—Structural Relationships in Molecules. MAGNETOCHEMISTRY 2021. [DOI: 10.3390/magnetochemistry7120158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This publication reviews recent advances in polarized neutron diffraction (PND) studies of magnetic anisotropy in coordination compounds comprising d or f elements and having different nuclearities. All these studies illustrate the extent to which PND can provide precise and direct information on the relationship between molecular structure and the shape and axes of magnetic anisotropy of the individual metal sites. It makes this experimental technique (PND) an excellent tool to help in the design of molecular-based magnets and especially single-molecule magnets for which strong uniaxial magnetic anisotropy is required.
Collapse
|
3
|
Spectroscopic Studies of the Magnetic Excitation and Spin‐Phonon Couplings in a Single‐Molecule Magnet. Chemistry 2019; 25:15846-15857. [DOI: 10.1002/chem.201903635] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Indexed: 12/11/2022]
|
4
|
Dunstan MA, Mole RA, Boskovic C. Inelastic Neutron Scattering of Lanthanoid Complexes and Single‐Molecule Magnets. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201801306] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Maja A. Dunstan
- School of Chemistry University of Melbourne Parkville, Victoria, 3010 Australia
| | - Richard A. Mole
- Australian Centre for Neutron Scattering Australian Nuclear Science and Technology Organisation Locked Bag 2001, Kirrawee DC, NSW, 2232 Australia
| | - Colette Boskovic
- School of Chemistry University of Melbourne Parkville, Victoria, 3010 Australia
| |
Collapse
|
5
|
Xue Z, Ramirez‐Cuesta AJ, Brown CM, Calder S, Cao H, Chakoumakos BC, Daemen LL, Huq A, Kolesnikov AI, Mamontov E, Podlesnyak AA, Wang X. Neutron Instruments for Research in Coordination Chemistry. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201801076] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zi‐Ling Xue
- Department of Chemistry University of Tennessee 37996 Knoxville Tennessee United States
| | - Anibal J. Ramirez‐Cuesta
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Craig M. Brown
- Center for Neutron Research National Institute of Standards and Technology 20899 Gaithersburg Maryland United States
- Department of Chemical and Biomolecular Engineering University of Delaware 19716 Newark Delaware United States
| | - Stuart Calder
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Huibo Cao
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Bryan C. Chakoumakos
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Luke L. Daemen
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Ashfia Huq
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Alexander I. Kolesnikov
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Eugene Mamontov
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Andrey A. Podlesnyak
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Xiaoping Wang
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| |
Collapse
|
6
|
Stavretis SE, Cheng Y, Daemen LL, Brown CM, Moseley DH, Bill E, Atanasov M, Ramirez-Cuesta AJ, Neese F, Xue ZL. Probing Magnetic Excitations in CoII
Single-Molecule Magnets by Inelastic Neutron Scattering. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201801088] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Shelby E. Stavretis
- Department of Chemistry; University of Tennessee; 37996 Knoxville Tennessee USA
| | - Yongqiang Cheng
- Neutron Scattering Division; Oak Ridge National Laboratory; 37831 Oak Ridge Tennessee USA
| | - Luke L. Daemen
- Neutron Scattering Division; Oak Ridge National Laboratory; 37831 Oak Ridge Tennessee USA
| | - Craig M. Brown
- NIST Center for Neutron Research; National Institute of Standards and Technology; 20899 Gaithersburg Maryland USA
- Department of Chemical and Biomolecular Engineering; University of Delaware; 19716 Newark Delaware USA
| | - Duncan H. Moseley
- Department of Chemistry; University of Tennessee; 37996 Knoxville Tennessee USA
| | - Eckhard Bill
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 45470 Mülheim an der Ruhr Germany
| | - Mihail Atanasov
- Max Planck Institute for Coal Research; Kaiser-Wilhelm-Platz 1, D -45470 Mülheim an der Ruhr Germany
- Institute of General and Inorganic Chemistry; Bulgarian Academy of Sciences; 1113 Sofia Bulgaria
| | | | - Frank Neese
- Max Planck Institute for Coal Research; Kaiser-Wilhelm-Platz 1, D -45470 Mülheim an der Ruhr Germany
| | - Zi-Ling Xue
- Department of Chemistry; University of Tennessee; 37996 Knoxville Tennessee USA
| |
Collapse
|
7
|
Chen L, Cui HH, Stavretis SE, Hunter SC, Zhang YQ, Chen XT, Sun YC, Wang Z, Song Y, Podlesnyak AA, Ouyang ZW, Xue ZL. Slow Magnetic Relaxations in Cobalt(II) Tetranitrate Complexes. Studies of Magnetic Anisotropy by Inelastic Neutron Scattering and High-Frequency and High-Field EPR Spectroscopy. Inorg Chem 2016; 55:12603-12617. [PMID: 27989182 DOI: 10.1021/acs.inorgchem.6b01544] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Three mononuclear cobalt(II) tetranitrate complexes (A)2[Co(NO3)4] with different countercations, Ph4P+ (1), MePh3P+ (2), and Ph4As+ (3), have been synthesized and studied by X-ray single-crystal diffraction, magnetic measurements, inelastic neutron scattering (INS), high-frequency and high-field EPR (HF-EPR) spectroscopy, and theoretical calculations. The X-ray diffraction studies reveal that the structure of the tetranitrate cobalt anion varies with the countercation. 1 and 2 exhibit highly irregular seven-coordinate geometries, while the central Co(II) ion of 3 is in a distorted-dodecahedral configuration. The sole magnetic transition observed in the INS spectroscopy of 1-3 corresponds to the zero-field splitting (2(D2 + 3E2)1/2) from 22.5(2) cm-1 in 1 to 26.6(3) cm-1 in 2 and 11.1(5) cm-1 in 3. The positive sign of the D value, and hence the easy-plane magnetic anisotropy, was demonstrated for 1 by INS studies under magnetic fields and HF-EPR spectroscopy. The combined analyses of INS and HF-EPR data yield the D values as +10.90(3), +12.74(3), and +4.50(3) cm-1 for 1-3, respectively. Frequency- and temperature-dependent alternating-current magnetic susceptibility measurements reveal the slow magnetization relaxation in 1 and 2 at an applied dc field of 600 Oe, which is a characteristic of field-induced single-molecule magnets (SMMs). The electronic structures and the origin of magnetic anisotropy of 1-3 were revealed by calculations at the CASPT2/NEVPT2 level.
Collapse
Affiliation(s)
- Lei Chen
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210023, People's Republic of China
| | - Hui-Hui Cui
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210023, People's Republic of China
| | - Shelby E Stavretis
- Department of Chemistry, University of Tennessee , Knoxville, Tennessee 37996, United States
| | - Seth C Hunter
- Department of Chemistry, University of Tennessee , Knoxville, Tennessee 37996, United States
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University , Nanjing 210023, People's Republic of China
| | - Xue-Tai Chen
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210023, People's Republic of China
| | - Yi-Chen Sun
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology , Wuhan 430074, People's Republic of China
| | - Zhenxing Wang
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology , Wuhan 430074, People's Republic of China
| | - You Song
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210023, People's Republic of China
| | - Andrey A Podlesnyak
- Quantum Condensed Matter Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Zhong-Wen Ouyang
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology , Wuhan 430074, People's Republic of China
| | - Zi-Ling Xue
- Department of Chemistry, University of Tennessee , Knoxville, Tennessee 37996, United States
| |
Collapse
|
8
|
Zlatar M, Gruden M, Vassilyeva OY, Buvaylo EA, Ponomarev AN, Zvyagin SA, Wosnitza J, Krzystek J, Garcia-Fernandez P, Duboc C. Origin of the Zero-Field Splitting in Mononuclear Octahedral Mn(IV) Complexes: A Combined Experimental and Theoretical Investigation. Inorg Chem 2016; 55:1192-201. [PMID: 26745448 DOI: 10.1021/acs.inorgchem.5b02368] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The aim of this work was to determine and understand the origin of the electronic properties of Mn(IV) complexes, especially the zero-field splitting (ZFS), through a combined experimental and theoretical investigation on five well-characterized mononuclear octahedral Mn(IV) compounds, with various coordination spheres (N6, N3O3, N2O4 in both trans (trans-N2O4) and cis configurations (cis-N2O4) and O4S2). High-frequency and -field EPR (HFEPR) spectroscopy has been applied to determine the ZFS parameters of two of these compounds, MnL(trans-N2O4) and MnL(O4S2). While at X-band EPR, the axial-component of the ZFS tensor, D, was estimated to be +0.47 cm(-1) for MnL(O4S2), and a D-value of +2.289(5) cm(-1) was determined by HFEPR, which is the largest D-magnitude ever measured for a Mn(IV) complex. A moderate D value of -0.997(6) cm(-1) has been found for MnL(trans-N2O4). Quantum chemical calculations based on two theoretical frameworks (the Density Functional Theory based on a coupled perturbed approach (CP-DFT) and the hybrid Ligand-Field DFT (LF-DFT)) have been performed to define appropriate methodologies to calculate the ZFS tensor for Mn(IV) centers, to predict the orientation of the magnetic axes with respect to the molecular ones, and to define and quantify the physical origin of the different contributions to the ZFS. Except in the case of MnL(trans-N2O4), the experimental and calculated D values are in good agreement, and the sign of D is well predicted, LF-DFT being more satisfactory than CP-DFT. The calculations performed on MnL(cis-N2O4) are consistent with the orientation of the principal anisotropic axis determined by single-crystal EPR, validating the calculated ZFS tensor orientation. The different contributions to D were analyzed demonstrating that the d-d transitions mainly govern D in Mn(IV) ion. However, a deep analysis evidences that many factors enter into the game, explaining why no obvious magnetostructural correlations can be drawn in this series of Mn(IV) complexes.
Collapse
Affiliation(s)
- Matija Zlatar
- Center for Chemistry, Institute of Chemistry, Technology and Metallurgy, University of Belgrade , Njegoševa 12, P.O. Box 815, 11001 Belgrade, Serbia
| | - Maja Gruden
- Faculty of Chemistry, University of Belgrade , Studentski trg 12-16, 11001 Belgrade, Serbia
| | - Olga Yu Vassilyeva
- Department of Chemistry, Taras Shevchenko National University of Kyiv , 64/13 Volodymyrska str., Kyiv 01601, Ukraine
| | - Elena A Buvaylo
- Department of Chemistry, Taras Shevchenko National University of Kyiv , 64/13 Volodymyrska str., Kyiv 01601, Ukraine
| | - A N Ponomarev
- Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), D-01328 Dresden, Saxony, Germany
| | - S A Zvyagin
- Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), D-01328 Dresden, Saxony, Germany
| | - J Wosnitza
- Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), D-01328 Dresden, Saxony, Germany.,Institut für Festkörperphysik, Technische Universität Dresden , D-01062 Dresden, Saxony, Germany
| | - J Krzystek
- National High Magnetic Field Laboratory (NHMFL), Florida State University , Tallahassee, Florida 32310, United States
| | - Pablo Garcia-Fernandez
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria , Avenida de los Castros s/n, 39005 Santander, Cantabria, Spain
| | - Carole Duboc
- Département de Chimie Moléculaire, Université Grenoble Alpes/CNRS, UMR-5250 , BP-53, 38041 Grenoble Cedex 9, France
| |
Collapse
|
9
|
Stavretis SE, Atanasov M, Podlesnyak AA, Hunter SC, Neese F, Xue ZL. Magnetic Transitions in Iron Porphyrin Halides by Inelastic Neutron Scattering and Ab Initio Studies of Zero-Field Splittings. Inorg Chem 2015; 54:9790-801. [DOI: 10.1021/acs.inorgchem.5b01505] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shelby E. Stavretis
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Mihail Atanasov
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße
34-36, D-45470 Mülheim
an der Ruhr, Germany
- Institute of General
and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Andrey A. Podlesnyak
- Quantum Condensed
Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Seth C. Hunter
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Frank Neese
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße
34-36, D-45470 Mülheim
an der Ruhr, Germany
| | - Zi-Ling Xue
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996, United States
| |
Collapse
|
10
|
Sigrist M, L. W. Tregenna‐Piggott P, S. Pedersen K, A. Sørensen M, Barra A, Hauser J, Liu S, Decurtins S, Mutka H, Bendix J. Zero‐Field Splitting in {Mn
III
3
(μ
3
‐O)} Core Single‐Molecule Magnets Investigated by Inelastic Neutron Scattering and High‐Field Electron Paramagnetic Resonance Spectroscopy. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201500084] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Marc Sigrist
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Institut Laue‐Langevin, 38042 Grenoble Cedex 9, France
- Present address: Institute of Chemistry, Academia Sinica, 128 Academia Rd Sec. 2, Nankang, Taipei 11529 Taiwan, ROC
| | | | - Kasper S. Pedersen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Present address: CNRS, CRPP, UPR 8641,33600 Pessac, France
| | - Mikkel A. Sørensen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Anne‐Laure Barra
- Grenoble High Magnetic Field Laboratory, CNRS, BP 166, 38042 Grenoble Cedex 9, France
| | - Jürg Hauser
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Shi‐Xia Liu
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Silvio Decurtins
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Hannu Mutka
- Institut Laue‐Langevin, 38042 Grenoble Cedex 9, France
| | - Jesper Bendix
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| |
Collapse
|
11
|
Rodriguez JH, Ziegler CJ. Geometric, electronic and magnetic structures of S = 19/2 and S = 20/2 thiophene-2-carboxylate functionalized Mn12 single molecule magnets. Dalton Trans 2015; 44:167-75. [PMID: 25360814 DOI: 10.1039/c4dt02703e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The geometric and magnetic structures of two structurally related, but magnetically inequivalent, single molecule magnets (SMMs) have been computationally characterized. The first SMM, with formula [Mn12O12(O2CC4H3S)16(H2O)2](-1) (I), has a half-integer spin (S(I) = 19/2) due to ferrimagnetic ordering. The second SMM, with formula Mn12O12(O2CC4H3S)16(H2O)4 (II), has an integer spin (S(II) = 20/2) and its geometric structure has been computationally predicted. Both SMMs include thiophene-2-carboxylate functional groups for potential use in molecular electronics. To determine structural and electronic differences between both SMMs, spin polarized density functional theory was applied to I and II. Hydrogen bonding of two and four Mn-bound water molecules in I and II, respectively, to thiophene-2-carboxylate oxygen atoms and inner cubane oxygen atoms is essential for structural stabilization of both complexes. The one-electron-reduction of I is concomitant with a structural asymmetry within its cubane whereby two ions, of nominal Mn(4+)(Si = 3/2) character, are inequivalent to the other two and acquire an incipient Mn(3+)(Si = 4/2) character. The geometric asymmetry in I provides an extra, albeit small, contribution to its zero field splitting and anisotropy barrier to spin reversal. Thus, despite its lower spin state, the anisotropy barrier of I is only slightly lower than that of II.
Collapse
Affiliation(s)
- Jorge H Rodriguez
- Department of Physics and Astronomy, Purdue University, W. Lafayette, IN 47907, USA.
| | | |
Collapse
|
12
|
González G, Leuenberger MN. Magnetic quantum coherence effect in Ni4 molecular transistors. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:275302. [PMID: 24918902 DOI: 10.1088/0953-8984/26/27/275302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present a theoretical study of electron transport in Ni4 molecular transistors in the presence of Zeeman spin splitting and magnetic quantum coherence (MQC). The Zeeman interaction is extended along the leads which produces gaps in the energy spectrum which allow electron transport with spin polarized along a certain direction. We show that the coherent states in resonance with the spin up or down states in the leads induces an effective coupling between localized spin states and continuum spin states in the single molecule magnet and leads, respectively. We investigate the conductance at zero temperature as a function of the applied bias and magnetic field by means of the Landauer formula, and show that the MQC is responsible for the appearence of resonances. Accordingly, we name them MQC resonances.
Collapse
Affiliation(s)
- Gabriel González
- Departamento de Matemáticas y Física, Instituto Tecnológico y de Estudios Superiores de Occidente, Periférico Sur Manuel Gómez Morín 8585 CP 45604, Tlaquepaque, Jal., Mexico
| | | |
Collapse
|
13
|
Romero JI, Mucciolo ER. Single-electron transport in a three-ion magnetic molecule modulated by a transverse field. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:195301. [PMID: 24763316 DOI: 10.1088/0953-8984/26/19/195301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We study single-electron transport in a three-ion molecule with strong uniaxial anisotropy and in the presence of a transverse magnetic field. Two magnetic ions are connected to each other through a third, nonmagnetic ion. The magnetic ions are coupled to ideal metallic leads and a back gate voltage is applied to the molecule, forming a field-effect transistor. The microscopic Hamiltonian describing this system includes inter-ion hopping, on-site repulsions and magnetic anisotropies. For a range of values of the parameters of the Hamiltonian, we obtain an energy spectrum similar to that of single-molecule magnets in the giant spin approximation where the two states with maximum spin projection along the uniaxial anisotropy axis are well separated from other states. In addition, upon applying an external in-plane magnetic field, the energy gap between the ground and first excited states of the molecule oscillates, going to zero at certain special values of the field, analogous to the diabolical points resulting from Berry phase interference in the giant spin model. Thus, our microscopic model provides the same phenomenological behavior expected from the giant spin model of a single-molecule magnet but with direct access to the internal structure of the molecule, thus making it more appropriate for realistic electronic transport studies. To illustrate this point, the nonlinear electronic transport in the sequential tunneling regime is evaluated for values of the field near these degeneracy points. We show that the existence of these points has a clear signature in the I-V characteristics of the molecule, most notably the modulation of excitation lines in the differential conductance.
Collapse
Affiliation(s)
- J I Romero
- Department of Physics, University of Central Florida, Orlando, FL 32816, USA
| | | |
Collapse
|
14
|
Hunter SC, Podlesnyak AA, Xue ZL. Magnetic Excitations in Metalloporphyrins by Inelastic Neutron Scattering: Determination of Zero-Field Splittings in Iron, Manganese, and Chromium Complexes. Inorg Chem 2014; 53:1955-61. [DOI: 10.1021/ic4028354] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Seth C. Hunter
- Department
of Chemistry, The University of Tennessee, 1420 Circle Drive, Knoxville, Tennessee 37996, United States
| | - Andrey A. Podlesnyak
- Quantum
Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Zi-Ling Xue
- Department
of Chemistry, The University of Tennessee, 1420 Circle Drive, Knoxville, Tennessee 37996, United States
| |
Collapse
|
15
|
Milios CJ, Winpenny REP. Cluster-Based Single-Molecule Magnets. MOLECULAR NANOMAGNETS AND RELATED PHENOMENA 2014. [DOI: 10.1007/430_2014_149] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
16
|
Bane K, Geiger RA, Chabolla SA, Jackson TA. Determination of zero-field splitting parameters for a MnIV center using variable-temperature, variable-field magnetic circular dichroism spectroscopy: Comparison to electron paramagnetic resonance spectroscopy. Inorganica Chim Acta 2012. [DOI: 10.1016/j.ica.2011.10.046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
17
|
Boukhvalov DW, Dobrovitski VV, Kögerler P, Al-Saqer M, Katsnelson MI, Lichtenstein AI, Harmon BN. Effect of Ligand Substitution on the Exchange Interactions in {Mn12}-Type Single-Molecule Magnets. Inorg Chem 2010; 49:10902-6. [DOI: 10.1021/ic101229p] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Danil W. Boukhvalov
- Computational Materials Science Center, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
- Radboud University Nijmegen, Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | | | - Paul Kögerler
- Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States
- Institute of Inorganic Chemistry, RWTH Aachen University, 52074 Aachen, Germany
| | - Mohammad Al-Saqer
- Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States
| | - Mikhail I. Katsnelson
- Radboud University Nijmegen, Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | | | - Bruce N. Harmon
- Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States
| |
Collapse
|
18
|
Clemente-Juan JM, Coronado E, Forment-Aliaga A, Gaita-Ariño A, Giménez-Saiz C, Romero FM, Wernsdorfer W, Biagi R, Corradini V. Electronic and magnetic study of polycationic Mn(12) single-molecule magnets with a ground spin state S = 11. Inorg Chem 2010; 49:386-96. [PMID: 19877595 DOI: 10.1021/ic901824d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The preparation, magnetic characterization, and X-ray structures of two polycationic Mn(12) single-molecule magnets [Mn(12)O(12)(bet)(16)(EtOH)(4)](PF(6))(14).4CH(3)CN.H(2)O (1) and [Mn(12)O(12)(bet)(16)(EtOH)(3)(H(2)O)](PF(6))(13)(OH).6CH(3)CN.EtOH.H(2)O (2) (bet = betaine = (CH(3))(3)N(+)-CH(2)-CO(2)(-)) are reported. 1 crystallizes in the centrosymmetric P2/c space group and presents a (0:2:0:2) arrangement of the EtOH molecules in its structure. 2 crystallizes in the noncentrosymmetric P4 space group with two distinct Mn(12) polycations, [Mn(12)O(12)(bet)(16)(EtOH)(2)(H(2)O)(2)](14+) (2A) and [Mn(12)O(12)(bet)(16)(EtOH)(4)](14+) (2B) per unit cell. 2A and 2B show a (1:1:1:1) distribution of the coordinated solvent molecules. Interestingly, bond valence sum calculations extracted from X-ray diffraction data indicate the presence of two Mn(2+) ions in the Mn(12) core for both 1 and 2. This finding is confirmed by X-ray absorption spectroscopy (XAS) measurements. A complete magnetic characterization, including subkelvin micro-SQUID magnetometry and inelastic neutron scattering (INS) measurements, permits to extract the parameters of the giant spin Hamiltonian of these polycations. Compared with the archetypal Mn(12) acetate, an increase in the value of the ground spin state from S = 10 to S = 11 together with a decrease in the effective energy barrier, is observed for 1 and 2. Such a result is consistent with the reduction of two Mn(3+) to the less anisotropic Mn(2+) ion in the structures.
Collapse
Affiliation(s)
- Juan M Clemente-Juan
- Instituto de Ciencia Molecular, Universitat de València, Polígono de la Coma, s/n 46980 Paterna, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Barraza-Lopez S, Park K, García-Suárez V, Ferrer J. First-principles study of electron transport through the single-molecule magnet Mn12. PHYSICAL REVIEW LETTERS 2009; 102:246801. [PMID: 19659035 DOI: 10.1103/physrevlett.102.246801] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Indexed: 05/28/2023]
Abstract
We examine electron transport through a single-molecule magnet Mn(12) bridged between Au electrodes using the first-principles method. We find crucial features which were inaccessible in model Hamiltonian studies: spin filtering and a strong dependence of charge distribution on local environments. The spin filtering remains robust with different molecular geometries and interfaces, and strong electron correlations, while the charge distribution over the Mn(12) strongly depends on them. We point out a qualitative difference between locally charged and free-electron-charged Mn(12).
Collapse
Affiliation(s)
- Salvador Barraza-Lopez
- Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | | | | | | |
Collapse
|
20
|
Bagai R, Christou G. The Drosophila of single-molecule magnetism: [Mn12O12(O2CR)16(H2O)4]. Chem Soc Rev 2009; 38:1011-26. [PMID: 19421579 DOI: 10.1039/b811963e] [Citation(s) in RCA: 520] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Single-molecule magnets (SMMs) are individual molecules that can function as nanoscale magnetic particles. The [Mn12O12(O2CR)16(H2O)4] (Mn12; R=Me, Et, etc.) family of SMMs was the first one discovered; it is also the one whose study has provided the majority of current knowledge on this interesting magnetic phenomenon, prompting its description here as the Drosophila of the field. This tutorial review will survey the various chemical studies that have been carried out to date on this family. This will include a discussion of methods that have been developed for their structural and redox transformation, and the effect of the latter on the magnetic and SMM properties.
Collapse
Affiliation(s)
- Rashmi Bagai
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA
| | | |
Collapse
|
21
|
González G, Leuenberger MN. Berry-phase blockade in single-molecule magnets. PHYSICAL REVIEW LETTERS 2007; 98:256804. [PMID: 17678045 DOI: 10.1103/physrevlett.98.256804] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Indexed: 05/16/2023]
Abstract
We formulate the problem of electron transport through a single-molecule magnet (SMM) in the Coulomb blockade regime taking into account topological interference effects for the tunneling of the large spin of a SMM. The interference originates from spin Berry phases associated with different tunneling paths. We show that, in the case of incoherent spin states, it is essential to place the SMM between oppositely spin-polarized source and drain leads in order to detect the spin tunneling in the stationary current, which exhibits topological zeros as a function of the transverse magnetic field.
Collapse
Affiliation(s)
- Gabriel González
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, USA
| | | |
Collapse
|
22
|
Leuenberger MN, Mucciolo ER. Berry-phase oscillations of the Kondo effect in single-molecule magnets. PHYSICAL REVIEW LETTERS 2006; 97:126601. [PMID: 17025987 DOI: 10.1103/physrevlett.97.126601] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Indexed: 05/07/2023]
Abstract
We show that it is possible to topologically induce or quench the Kondo resonance in the conductance of a single-molecule magnet (S>1/2) strongly coupled to metallic leads. This can be achieved by applying a magnetic field perpendicular to the molecule easy axis and works for both full- and half-integer spin cases. The effect is caused by the Berry-phase interference between two quantum tunneling paths of the molecule's spin. We have calculated the renormalized Berry-phase oscillations of the Kondo peaks as a function of the transverse magnetic field as well as the conductance of the molecule by means of the poor man's scaling method. We propose to use a new variety of the single-molecule magnet Ni4 for the experimental observation of this phenomenon.
Collapse
Affiliation(s)
- Michael N Leuenberger
- NanoScience Technology Center, University of Central Florida, Orlando, FL 32826, USA.
| | | |
Collapse
|
23
|
|
24
|
|
25
|
Chakov NE, Soler M, Wernsdorfer W, Abboud KA, Christou G. Single-Molecule Magnets: Structural Characterization, Magnetic Properties, and19F NMR Spectroscopy of a Mn12Family Spanning Three Oxidation Levels. Inorg Chem 2005; 44:5304-21. [PMID: 16022529 DOI: 10.1021/ic050379w] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The syntheses, crystal structures, and magnetic properties of [Mn(12)O(12)(O(2)CC(6)F(5))(16)(H(2)O)(4)] (2), (NMe(4))[Mn(12)O(12)(O(2)CC(6)F(5))(16)(H(2)O)(4)] (3), and (NMe(4))(2)[Mn(12)O(12)(O(2)CC(6)F(5))(16)(H(2)O)(4)] (4) are reported. Complex 2 displays quasi-reversible redox couples when examined by cyclic voltammetry in CH(2)Cl(2): one-electron reductions are observed at 0.64 and 0.30 V vs ferrocene. The reaction of complex 2 with 1 and 2 equiv of NMe(4)I yields the one- and two-electron reduced analogues, 3 and 4, respectively. Complexes 2.3CH(2)Cl(2), 3.4.5CH(2)Cl(2).(1)/(2)H(2)O, and 4.6C(7)H(8) crystallize in the triclinic P, monoclinic P2/c, and monoclinic C2/c space groups, respectively. The molecular structures are all very similar, consisting of a central [Mn(IV)O(4)] cubane surrounded by a nonplanar alternating ring of eight Mn and eight mu(3)-O(2)(-) ions. Peripheral ligation is provided by 16 bridging C(6)F(5)CO(2)(-) and 4 H(2)O ligands. Bond valence sum calculations establish that the added electrons in 3 and 4 are localized on former Mn(III) ions giving trapped-valence Mn(IV)(4)Mn(III)(7)Mn(II) and Mn(IV)(4)Mn(III)(6)Mn(II)(2) anions, respectively. (19)F NMR spectroscopy in CD(2)Cl(2) shows retention of the solid-state structure upon dissolution and detrapping of the added electrons in 3 and 4 among the outer ring of Mn ions on the (19)F NMR time scale. DC studies on dried microcrystalline samples of 2, 3, and 4.2.5C(7)H(8) restrained in eicosane in the 1.80-10.0 K and 1-70 kG ranges were fit to give S = 10, D = -0.40 cm(-)(1), g = 1.87, D/g = 0.21 cm(-)(1) for 2, S = 19/2, D = -0.34 cm(-)(1), g = 2.04, D/g = 0.17 cm(-)(1) for 3, and S = 10, D = -0.29 cm(-)(1), g = 2.05, D/g = 0.14 cm(-)(1) for 4, where D is the axial zero-field splitting parameter. The clusters exhibit out-of-phase AC susceptibility signals (chi(M)' ') indicative of slow magnetization relaxation in the 6-8 K range for 2, 4-6 K range for 3, and 2-4 K range for 4; the shift to lower temperatures reflects the decreasing magnetic anisotropy upon successive reduction and, hence, the decreasing energy barrier to magnetization relaxation. Relaxation rate vs T data obtained from chi(M)' ' vs AC oscillation frequency studies down to 1.8 K were combined with rate vs T data from DC magnetization decay vs time measurements at lower temperatures to generate an Arrhenius plot from which the effective barrier (U(eff)) to magnetization reversal was obtained; the U(eff) values are 59 K for 2, 49 and 21 K for the slower- and faster-relaxing species of 3, respectively, and 25 K for 4. Hysteresis loops obtained from single-crystal magnetization vs DC field scans are typical of single-molecule magnets with the coercivities increasing with decreasing T and increasing field sweep rate and containing steps caused by the quantum tunneling of magnetization (QTM). The step separations gave D/g values of 0.22 cm(-)(1) for 2, 0.15 and 0.042 cm(-)(1) for the slower- and faster-relaxing species of 3, and 0.15 cm(-)(1) for 4.
Collapse
Affiliation(s)
- Nicole E Chakov
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA
| | | | | | | | | |
Collapse
|