A series of new vanadium(iii) chalcogenido-antimonates: an unusual seven-coordinate nitro-selenidovanadium(iii) complex

Abstract

A series of new vanadium(III) chalcogenidoantimonates [V^III(dap)₂SbQ₃] (Q = S (1), Se (2); dap = 1,2-diaminopropane), [H₂dien][V^III₂(en)₂(dien)₂(μ₂-O)][SbSe₄]₂ (3, en = ethylenediamine; dien = diethylenetriamine) and [V^III(dien)₂SbSe₄] (4) have been solvothermally synthesized and structurally characterized. Both 1 and 2 contain neutral vanadium(III)-centered complexes [V^III(dap)₂SbQ₃], where the [SbQ₃]³⁻ anion acts as a chelating ligand to complex [V^III(dap)₂]³⁺, but they exhibit different molecular conformations. 3 consists of selenidoantimonate anions [SbSe₄]³⁻, the protonated H₂dien²⁺ cation, and the dinuclear complex [V^III₂(en)₂(dien)₂(μ₂-O)]⁴⁺ based on two [V^III(en)(dien)]³⁺ units bridged by one μ₂-O group. 4 contains neutral [V^III(dien)₂SbSe₄] moieties with seven coordinated vanadium centres, which offers a rare example of high coordination of a nitro-selenidovanadium(III) complex, mainly because the vanadium(III) ion has a regular octahedral configuration based on the structures in the solid state. The optical, magnetic and photoelectronic properties of all compounds have been investigated, and the density functional theory calculation of 4 has also been studied.