TY - JOUR

T1 - Dinuclear Vanadium Sulfide Clusters

T2 - Synthesis, Redox Behavior, and Magnetic Properties

AU - Fomenko, Iakov S.

AU - Gushchin, Artem L.

AU - Nadolinny, Vladimir A.

AU - Efimov, Nikolay N.

AU - Laricheva, Yuliya A.

AU - Sokolov, Maxim N.

N1 - Publisher Copyright: © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

PY - 2018/7/6

Y1 - 2018/7/6

N2 - The complex [V2S4(nBu2dtc)4] (1) (dtc = dithiocarbamate) was prepared by a self-assembly reaction from [VO(nBu2dtc)3] and H2S. 1H, 13C, and 51V NMR spectra indicate the presence in solution of two isomers (centrosymmetric and non-centrosymmetric) with different relative orientations of the dithiocarbamate chelate rings. Thermogravimetric studies of 1 show that the thermolysis products are VS2 (in He) or VS (in H2). The cyclic voltammogram (CV) in dichloromethane reveals a chemically reversible one-electron oxidation at +0.61 V followed by an irreversible oxidation at +1.51 V (vs. Ag/AgCl). The redox processes can be attributed to V-centered oxidation. This interpretation is supported by DFT calculations, indicating the predominantly V–V bonding character of the HOMO in both cases. The removal of one electron from the HOMO causes weakening of the V–V bond in 1+. The mixed-valence V(IV/V) product of the one-electron oxidation, [V2S4(nBu2dtc)4](BF4) {[1](BF4)}, was isolated from the reaction with NOBF4 and characterized by elemental analysis, IR spectroscopy, mass spectrometry (ESI-MS), CV, EPR spectroscopy, and magnetochemistry. The EPR spectrum of [1](BF4) in dichloromethane exhibits a single 15-line signal arising from the hyperfine interaction between the unpaired electron and two equivalent 51V nuclei with I = 7/2, indicating complete delocalization of the unpaired electron over both metal centers. The magnetic behavior of [1](BF4) confirms the presence of one unpaired electron and the mixed-valence V(IV/V) oxidation state without any significant magnetic exchange interactions between the paramagnetic complexes.

AB - The complex [V2S4(nBu2dtc)4] (1) (dtc = dithiocarbamate) was prepared by a self-assembly reaction from [VO(nBu2dtc)3] and H2S. 1H, 13C, and 51V NMR spectra indicate the presence in solution of two isomers (centrosymmetric and non-centrosymmetric) with different relative orientations of the dithiocarbamate chelate rings. Thermogravimetric studies of 1 show that the thermolysis products are VS2 (in He) or VS (in H2). The cyclic voltammogram (CV) in dichloromethane reveals a chemically reversible one-electron oxidation at +0.61 V followed by an irreversible oxidation at +1.51 V (vs. Ag/AgCl). The redox processes can be attributed to V-centered oxidation. This interpretation is supported by DFT calculations, indicating the predominantly V–V bonding character of the HOMO in both cases. The removal of one electron from the HOMO causes weakening of the V–V bond in 1+. The mixed-valence V(IV/V) product of the one-electron oxidation, [V2S4(nBu2dtc)4](BF4) {[1](BF4)}, was isolated from the reaction with NOBF4 and characterized by elemental analysis, IR spectroscopy, mass spectrometry (ESI-MS), CV, EPR spectroscopy, and magnetochemistry. The EPR spectrum of [1](BF4) in dichloromethane exhibits a single 15-line signal arising from the hyperfine interaction between the unpaired electron and two equivalent 51V nuclei with I = 7/2, indicating complete delocalization of the unpaired electron over both metal centers. The magnetic behavior of [1](BF4) confirms the presence of one unpaired electron and the mixed-valence V(IV/V) oxidation state without any significant magnetic exchange interactions between the paramagnetic complexes.

KW - Cyclic voltammetry

KW - Dithiocarbamates

KW - EPR

KW - Magnetochemistry

KW - Mixed-valent complexes

KW - Sulfide clusters

KW - Vanadium

KW - NIOBIUM

KW - COMPLEXES

KW - REACTIVITY

KW - CHALCOGENIDE CLUSTERS

KW - LIGANDS

KW - ELECTRONIC-STRUCTURE

UR - http://www.scopus.com/inward/record.url?scp=85049567710&partnerID=8YFLogxK

U2 - 10.1002/ejic.201800449

DO - 10.1002/ejic.201800449

M3 - Article

AN - SCOPUS:85049567710

VL - 2018

SP - 2965

EP - 2971

JO - European Journal of Inorganic Chemistry

JF - European Journal of Inorganic Chemistry

SN - 1434-1948

IS - 25

ER -