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Frøen EH, Adler P, Valldor M. Synthesis and Properties of Ba 6Fe 2Te 3S 7, with an Fe Dimer in a Magnetic Singlet State. Inorg Chem 2023; 62:12548-12556. [PMID: 37487201 PMCID: PMC10410609 DOI: 10.1021/acs.inorgchem.3c01775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Indexed: 07/26/2023]
Abstract
A new quaternary sulfide telluride, Ba6Fe2Te3S7, was synthesized by a solid-state reaction, and its crystal structure is novel. X-ray diffraction data on powder and single crystals reveal an orthorhombic lattice with a = 9.7543(3) Å, b = 18.2766(6) Å, and c = 12.0549(4) Å, and the noncentrosymmetric space group Cmc21 (No. 36). The properties of the compound were studied by magnetic susceptibility investigations, specific heat measurements, Mössbauer spectroscopy, and density functional theory calculations. Assuming Ba2+ and, as verified by the Mössbauer spectra, Fe3+, the charge balance requires the presence of a polytelluride, suggested to be a straight-chain [Te34-] polyanion. Further, the crystal structure contains [Fe2S7]8- dimers of two vertex-sharing tetrahedra, with a nearly linear Fe-S-Fe atom arrangement. The dimer exhibits antiferromagnetic coupling, with a coupling constant J = -10.5 meV (H = -2JS1S2) and S = 5/2, resulting in a spin singlet ground state. The interdimer magnetic interaction is so weak that the magnetic dimers can be treated as individuals.
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Affiliation(s)
- Emil H. Frøen
- Centre
for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, Sem Sælands vei 26, NO-0371 Oslo, Norway
| | - Peter Adler
- Max-Planck-Institute
for Chemical Physics of Solids, Nöthnitzer Straße 40, DE-01187 Dresden, Germany
| | - Martin Valldor
- Centre
for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, Sem Sælands vei 26, NO-0371 Oslo, Norway
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Yu H, Sun J, Heine T. Predicting Magnetic Coupling and Spin-Polarization Energy in Triangulene Analogues. J Chem Theory Comput 2023. [PMID: 37263582 DOI: 10.1021/acs.jctc.3c00175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Triangulene and its analogue metal-free magnetic systems have garnered increasing attention since their discovery. Predicting the magnetic coupling and spin-polarization energy with quantitative accuracy is beyond the predictive power of today's density functional theory (DFT) due to their intrinsic multireference character. Herein, we create a benchmark dataset of 25 magnetic systems with nonlocal spin densities, including the triangulene monomer, dimer, and their analogues. We calculate the magnetic coupling (J) and spin-polarization energy (ΔEspin) of these systems using complete active space self-consistent field (CASSCF) and coupled-cluster methods as high-quality reference values. This reference data is then used to benchmark 22 DFT functionals commonly used in material science. Our results show that, while some functionals consistently correctly predict the qualitative character of the ground state, achieving quantitative accuracy with small relative errors is currently not feasible. PBE0, M06-2X, and MN15 are predicting the correct electronic ground state for all systems investigated here and also have the lowest mean absolute error for predicting both ΔEspin (0.34, 0.32, and 0.31 eV) and J (11.74, 12.66, and 10.64 meV). They may therefore also serve as starting points for higher-level methods such as the GW or the random phase approximation. As other functionals fail for the prediction of the ground state, they cannot be recommended for metal-free magnetic systems.
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Affiliation(s)
- Hongde Yu
- Faculty of Chemistry and Food Chemistry, TU Dresden, 01069 Dresden, Germany
| | - Jianwei Sun
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, United States
| | - Thomas Heine
- Faculty of Chemistry and Food Chemistry, TU Dresden, 01069 Dresden, Germany
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, 04316 Leipzig, Germany
- Department of Chemistry, Yonsei University and IBS CNM, Seoul 120-749, Korea
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Duplaix-Rata G, Le Guennic B, David G. Revisiting magnetic exchange couplings in heterodinuclear complexes through the decomposition method in KS-DFT. Phys Chem Chem Phys 2023; 25:14170-14178. [PMID: 37162514 DOI: 10.1039/d3cp00697b] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Providing tools to understand the physical mechanisms governing magnetic properties in transition metal-based compounds is still of great interest. Here, the magnetic exchange coupling in a series of heterodinuclear complexes is investigated by means of the decomposition method. This work presents the first application of the decomposition method to systems where magnetic centres may bear more than one unpaired electron. By decomposing the coupling into three physical contributions (direct exchange, kinetic exchange, and spin polarisation), we provide numerical arguments to confirm or infirm the rationalisation allowed by the conceptual analysis of the magnetic d orbitals. We also take advantage of the recently proposed generalisation of the method [David et al., J. Chem. Theory Comput., 2023, 19, 157] to get more insights into the underlying mechanisms by disentangling the coupling between centres into its electron-electron interactions.
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Affiliation(s)
- 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.
| | - Grégoire David
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France.
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Luo S, Shen X, Gao P, Tu T, Sun X. Magneto-structural maps and bridged-ligand effect for dichloro-bridged dinuclear copper(ii) complexes: a theoretical perspective. RSC Adv 2023; 13:12430-12437. [PMID: 37091610 PMCID: PMC10116190 DOI: 10.1039/d3ra00585b] [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: 01/28/2023] [Accepted: 04/17/2023] [Indexed: 04/25/2023] Open
Abstract
Theoretical understanding of magneto-structural correlations in dichloro-bridged dicopper(ii) complexes can guide the design of magnetic materials having broad-scale applications. However, previous reports suggest these correlations are complicated and unclear. To clarify possible correlations, magnetic coupling constants (J calc) of variants of a representative {Cu-(μ-Cl)2-Cu} complex A were calculated through BS-DFT. The variation of the Cu-(μ-Cl)-Cu angle (α), Cu⋯Cu distance (R 0), and Cu-Cl-Cu-Cl dihedral angle (τ) followed by structural optimization and calculation of the magnetic coupling constant (J calc) revealed several trends. J calc increased linearly with R 0 and τ, and initially increased and then decreased with α. Further, bridging ligand effects on J calc for dicopper(ii) complexes were evaluated through BS-DFT; the results revealed that J calc increased with increasing ligand field strength (I- < Br- < Cl- < N3 - < F-). Furthermore, a linear relationship was found between the spin density of the bridging ligand and J calc.
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Affiliation(s)
- Shuchang Luo
- College of Chemical Engineering, Guizhou University of Engineering Science Bijie 551700 People's Republic of China
- The Coal Chemical Engineering, 2011 Collaborative Innovation Center of Guizhou Province Bijie 551700 People's Republic of China
- Guizhou Province Key Laboratory of Ecological Protection and Restoration of Typical Plateau Wetlands Bijie 551700 People's Republic of China
| | - Xianwei Shen
- College of Chemical Engineering, Guizhou University of Engineering Science Bijie 551700 People's Republic of China
- The Coal Chemical Engineering, 2011 Collaborative Innovation Center of Guizhou Province Bijie 551700 People's Republic of China
| | - Peng Gao
- College of Chemical Engineering, Guizhou University of Engineering Science Bijie 551700 People's Republic of China
- The Coal Chemical Engineering, 2011 Collaborative Innovation Center of Guizhou Province Bijie 551700 People's Republic of China
| | - Ting Tu
- College of Chemical Engineering, Guizhou University of Engineering Science Bijie 551700 People's Republic of China
- The Coal Chemical Engineering, 2011 Collaborative Innovation Center of Guizhou Province Bijie 551700 People's Republic of China
| | - Xiaoyuan Sun
- College of Chemical Engineering, Guizhou University of Engineering Science Bijie 551700 People's Republic of China
- The Coal Chemical Engineering, 2011 Collaborative Innovation Center of Guizhou Province Bijie 551700 People's Republic of China
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Abdullin D, Hett T, Fleck N, Kopp K, Cassidy S, Richert S, Schiemann O. Magneto-Structural Correlations in a Mixed Porphyrin(Cu 2+ )/Trityl Spin System: Magnitude, Sign, and Distribution of the Exchange Coupling Constant. Chemistry 2023; 29:e202203148. [PMID: 36519664 DOI: 10.1002/chem.202203148] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
Tetrathiatriarylmethyl radicals (TAM or trityl) are receiving increasing attention in various fields of magnetic resonance such as imaging, dynamic nuclear polarization, spin labeling, and, more recently, molecular magnetism and quantum information technology. Here, a trityl radical attached via a phenyl bridge to a copper(II)tetraphenylporphyrin was synthesized, and its magnetic properties studied by multi-frequency continuous-wave electron paramagnetic resonance (EPR) spectroscopy and magnetic measurements. EPR revealed that the electron spin-spin coupling constant J between the trityl and Cu2+ spin centers is ferromagnetic with a magnitude of -2.3 GHz (-0.077 cm-1 , + J S → 1 S → 2 ${+J{\vec{S}}_{1}{\vec{S}}_{2}}$ convention) and a distribution width of 1.2 GHz (0.040 cm-1 ). With the help of density functional theory (DFT) calculations, the obtained ferromagnetic exchange coupling, which is unusual for para-substituted phenyl-bridged biradicals, could be related to the almost perpendicular orientation of the phenyl linker with respect to the porphyrin and trityl ring planes in the energy minimum, while the J distribution was rationalized by the temperature weighted rotation of the phenyl bridge about the molecular axis connecting both spin centers. This study exemplifies the importance of molecular dynamics for the homogeneity (or heterogeneity) of the magnetic properties of trityl-based systems.
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Affiliation(s)
- Dinar Abdullin
- Clausius-Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany
| | - Tobias Hett
- Clausius-Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany
| | - Nico Fleck
- Clausius-Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany.,Merck KGaA, Q20/001, Frankfurterstr. 250, 64293, Darmstadt, Germany
| | - Kevin Kopp
- Clausius-Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany
| | - Simon Cassidy
- Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK
| | - Sabine Richert
- Institute of Physical Chemistry, University of Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Olav Schiemann
- Clausius-Institute of Physical and Theoretical Chemistry, University of Bonn, Wegelerstr. 12, 53115, Bonn, Germany.,Department of Chemical and Biological Physics, Weizmann Institute of Science, 761001, Rehovot, Israel
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Petrikat RI, Steiger ST, Barani E, Boden PJ, Huber ME, Ringenberg MR, Niedner-Schatteburg G, Fink K, Becker S. Cooperativity-Driven Reactivity of a Dinuclear Copper Dimethylglyoxime Complex. Chemistry 2023; 29:e202203438. [PMID: 36807660 DOI: 10.1002/chem.202203438] [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: 11/05/2022] [Revised: 02/17/2023] [Accepted: 02/20/2023] [Indexed: 02/22/2023]
Abstract
In this report, we present the dinuclear copper(II) dimethylglyoxime (H2 dmg) complex [Cu2 (H2 dmg)(Hdmg)(dmg)]+ (1), which, in contrast to its mononuclear analogue [Cu(Hdmg)2 ] (2), is subject to a cooperativity-driven hydrolysis. The combined Lewis acidity of both copper centers increases the electrophilicity of the carbon atom in the bridging μ2 -O-N=C-group of H2 dmg and thus, facilitates the nucleophilic attack of H2 O. This hydrolysis yields butane-2,3-dione monoxime (3) and NH2 OH that, depending on the solvent, is then either oxidized or reduced. In ethanol, NH2 OH is reduced to NH4 + , yielding acetaldehyde as the oxidation product. In contrast, in CH3 CN, NH2 OH is oxidized by CuII to form N2 O and [Cu(CH3 CN)4 ]+ . Herein are presented the combined synthetic, theoretical, spectroscopic and spectrometric methods that indicate and establish the reaction pathway of this solvent-dependent reaction.
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Affiliation(s)
- Raphael I Petrikat
- RPTU Kaiserslautern-Landau, Institut für Anorganische Chemie, Erwin-Schroedinger-Str. 54, 67663, Kaiserslautern, Germany
| | - Sophie T Steiger
- RPTU Kaiserslautern-Landau, Institut für Physikalische Chemie, Erwin-Schroedinger-Str. 52, 67663, Kaiserslautern, Germany
| | - Elham Barani
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Pit J Boden
- RPTU Kaiserslautern-Landau, Institut für Physikalische Chemie, Erwin-Schroedinger-Str. 52, 67663, Kaiserslautern, Germany
| | - Maximilian E Huber
- RPTU Kaiserslautern-Landau, Institut für Physikalische Chemie, Erwin-Schroedinger-Str. 52, 67663, Kaiserslautern, Germany
| | - Mark R Ringenberg
- Société Suisse des Explosifs, Fabrikstrasse 48, CH-3900, Brig, Switzerland
| | - Gereon Niedner-Schatteburg
- RPTU Kaiserslautern-Landau, Institut für Physikalische Chemie, Erwin-Schroedinger-Str. 52, 67663, Kaiserslautern, Germany
| | - Karin Fink
- Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Sabine Becker
- RPTU Kaiserslautern-Landau, Institut für Anorganische Chemie, Erwin-Schroedinger-Str. 54, 67663, Kaiserslautern, Germany
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7
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Effect of para substituents on magnetic properties of azido-Cu(II) complexes with benzoate/azide coligands: A theoretical perspective. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.115983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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8
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Leung K, Greathouse JA. Ab initio molecular dynamics free energy study of enhanced copper (II) dimerization on mineral surfaces. Commun Chem 2022; 5:76. [PMID: 36697693 PMCID: PMC9814296 DOI: 10.1038/s42004-022-00688-2] [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: 10/08/2021] [Accepted: 05/30/2022] [Indexed: 01/28/2023] Open
Abstract
Understanding the adsorption of isolated metal cations from water on to mineral surfaces is critical for toxic waste retention and cleanup in the environment. Heterogeneous nucleation of metal oxyhydroxides and other minerals on material surfaces is key to crystal growth and dissolution. The link connecting these two areas, namely cation dimerization and polymerization, is far less understood. In this work we apply ab initio molecular dynamics calculations to examine the coordination structure of hydroxide-bridged Cu(II) dimers, and the free energy changes associated with Cu(II) dimerization on silica surfaces. The dimer dissociation pathway involves sequential breaking of two Cu2+-OH- bonds, yielding three local minima in the free energy profiles associated with 0-2 OH- bridges between the metal cations, and requires the design of a (to our knowledge) novel reaction coordinate for the simulations. Cu(II) adsorbed on silica surfaces are found to exhibit stronger tendency towards dimerization than when residing in water. Cluster-plus-implicit-solvent methods yield incorrect trends if OH- hydration is not correctly depicted. The predicted free energy landscapes are consistent with fast equilibrium times (seconds) among adsorbed structures, and favor Cu2+ dimer formation on silica surfaces over monomer adsorption.
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Affiliation(s)
- Kevin Leung
- Sandia National Laboratories, MS 1415, Albuquerque, NM, USA.
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