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Deepanjali Pandey, Narvi SS, Kumar R, Marek J. Quantitative Intermolecular Interactions Analysis and Magnetic Properties of Thiocyanatoiron(II) Complex with Nicotinamide Ligand. RUSS J INORG CHEM+ 2022. [DOI: 10.1134/s0036023622100357] [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]
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Chegerev M, Demidov O, Vasilyev P, Efimov N, Kubrin S, Starikov A, Vlasenko V, Piskunov A, Shapovalova S, Guda A, Rusalev Y, Soldatov A. Spin transitions in ferric catecholate complexes mediated by outer-sphere counteranions. Dalton Trans 2022; 51:10909-10919. [PMID: 35792083 DOI: 10.1039/d2dt01207c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A family of ionic ferric catecholate complexes 1-4 bearing a disubstituted 3,6-di-tert-butyl-catecholate ligand (3,6-DBCatH2) and tetradentate tris(2-pyridylmethyl)amine (TPA) was prepared and its spin transitions were investigated. Variation of the outer-sphere counteranions (PF6, BPh4, ClO4, BF4) is accompanied by changes in the magnetic behavior of the compounds under consideration. The crystal structures of complexes 1, 3 and 4 were determined by single crystal X-ray diffraction analysis at 100 K and 293 K. The complexes were characterized by the occurrence of a thermally induced spin-crossover process in the solid state with different degrees of completeness, which was confirmed by the comprehensive spectroscopic investigation (EPR, magnetic susceptibility, Mössbauer, and XAS) of the isolated compounds. Complex 4 containing BF4 anions was found to demonstrate valence tautomeric transition along with spin-crossover. This finding makes compound 4 the first salt-like mononuclear ferric catecholate complex exhibiting valence tautomerism.
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Affiliation(s)
- Maxim Chegerev
- Institute of Physical and Organic Chemistry, Southern Federal University, Stachki Avenue, 194/2, 344090, Rostov-on-Don, Russia.
| | - Oleg Demidov
- North Caucasus Federal University, Pushkin st. 1, 355017, Stavropol, Russia
| | - Pavel Vasilyev
- Kurnakov Institute of General and Inorganic Chemistry, Leninsky avenue, 31, 119991, Moscow, Russia
| | - Nikolay Efimov
- Kurnakov Institute of General and Inorganic Chemistry, Leninsky avenue, 31, 119991, Moscow, Russia
| | - Stanislav Kubrin
- Institute of Physics, Southern Federal University, Stachki Ave., 194, 344090, Rostov-on-Don, Russia
| | - Andrey Starikov
- Institute of Physical and Organic Chemistry, Southern Federal University, Stachki Avenue, 194/2, 344090, Rostov-on-Don, Russia.
| | - Valery Vlasenko
- Institute of Physics, Southern Federal University, Stachki Ave., 194, 344090, Rostov-on-Don, Russia
| | - Alexander Piskunov
- Razuvaev Institute of Organometallic Chemistry, Russian Academy of Sciences, 49 Tropinina Str., GSP-445, 603950, Nizhny Novgorod, Russia
| | - Svetlana Shapovalova
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090, Rostov-on-Don, Russia
| | - Alexander Guda
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090, Rostov-on-Don, Russia
| | - Yury Rusalev
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090, Rostov-on-Don, Russia
| | - Alexander Soldatov
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, 344090, Rostov-on-Don, Russia
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Ershova IV, Bogomyakov AS, Kubrin SP, Cherkasov AV, Piskunov AV. Iron(III) Complexes Based on N-Benzylidene-2-Hydroxy-3,5-Di-tert-Butylaniline. RUSS J COORD CHEM+ 2021. [DOI: 10.1134/s1070328421010012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Minkin VI, Starikova AA, Chegerev MG, Starikov AG. Computer Simulation of the Structure and Magnetic Properties of Cobalt Complexes with N-Substituted Pyridinophanes and Radical-Functionalized o-Benzoquinones. RUSS J COORD CHEM+ 2020. [DOI: 10.1134/s1070328420060068] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Thorarinsdottir AE, Bjornsson R, Harris TD. Insensitivity of Magnetic Coupling to Ligand Substitution in a Series of Tetraoxolene Radical-Bridged Fe 2 Complexes. Inorg Chem 2020; 59:4634-4649. [PMID: 32196317 DOI: 10.1021/acs.inorgchem.9b03736] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The elucidation of magnetostructural correlations between bridging ligand substitution and strength of magnetic coupling is essential to the development of high-temperature molecule-based magnetic materials. Toward this end, we report the series of tetraoxolene-bridged FeII2 complexes [(Me3TPyA)2Fe2(RL)]n+ (Me3TPyA = tris(6-methyl-2-pyridylmethyl)amine; n = 2: OMeLH2 = 3,6-dimethoxy-2,5-dihydroxo-1,4-benzoquinone, ClLH2 = 3,6-dichloro-2,5-dihydroxo-1,4-benzoquinone, Na2[NO2L] = sodium 3,6-dinitro-2,5-dihydroxo-1,4-benzoquinone; n = 4: SMe2L = 3,6-bis(dimethylsulfonium)-2,5-dihydroxo-1,4-benzoquinone diylide) and their one-electron-reduced analogues. Variable-temperature dc magnetic susceptibility data reveal the presence of weak ferromagnetic superexchange between FeII centers in the oxidized species, with exchange constants of J = +1.2(2) (R = OMe, Cl) and +0.3(1) (R = NO2, SMe2) cm-1. In contrast, X-ray diffraction, cyclic voltammetry, and Mössbauer spectroscopy establish a ligand-centered radical in the reduced complexes. Magnetic measurements for the radical-bridged species reveal the presence of strong antiferromagnetic metal-radical coupling, with J = -57(10), -60(7), -58(6), and -65(8) cm-1 for R = OMe, Cl, NO2, and SMe2, respectively. The minimal effects of substituents in the 3- and 6-positions of RLx-• on the magnetic coupling strength is understood through electronic structure calculations, which show negligible spin density on the substituents and associated C atoms of the ring. Finally, the radical-bridged complexes are single-molecule magnets, with relaxation barriers of Ueff = 50(1), 41(1), 38(1), and 33(1) cm-1 for R = OMe, Cl, NO2, and SMe2, respectively. Taken together, these results provide the first examination of how bridging ligand substitution influences magnetic coupling in semiquinoid-bridged compounds, and they establish design criteria for the synthesis of semiquinoid-based molecules and materials.
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Affiliation(s)
| | - Ragnar Bjornsson
- Department of Inorganic Spectroscopy, Max-Planck-Institut für Chemische Energiekonversion, Mülheim an der Ruhr 45470, Germany
| | - T David Harris
- Department of Chemistry, Northwestern University, Evanston 60208, Illinois, United States.,Department of Chemistry, University of California, Berkeley 94720, California, United States
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