Features of the Molecular and Electronic Structures of the Vanadium(IV) Complex Based on Glyoxal-bis(2-hydroxy-3,5-di-tert-butylphenyl)Imine

Abstract

A seven-coordinate bisligand complex of vanadium(IV) (1) is formed as a result of the interaction between glyoxal-bis(2-hydroxy-3,5-di-tert-butylphenyl)imine LH₂ and vanadyl sulfate in the presence of Et₃N base. Its structure is determined by the single crystal X-ray diffraction analysis. The reaction is accompanied by redox processes involving LH₂ and its isomerization. The redox state of the ligands and the metal center in complex 1 is confirmed by quantum chemical computations. One of the organic ligands is the radical trianion and is tetradentate coordinated by the metal atom. The second being the monoanion undergoes intramolecular oxidative cyclization and is characterized by tridentate coordination with vanadium(IV). Compound 1 is diamagnetic due to the strong antiferromagnetic interaction between the paramagnetic metal cation and the organic radical. The complex under study is additionally characterized by NMR, IR, UV spectroscopic techniques and cyclic voltammetry.