Rare examples of hybrid chalcogenoarsenate(III) incorporating trivalent vanadium complexes.

A series of new hybrid vanadium chalcogenoarsenates(III) [V III (en) 2 As III S 3 ] (1, en = ethylenediamine), [V III (dap) 2 As III Se 3 ] (2, dap = 1,2-diaminopropane), [V III (teta)As III Q 3 ] {Q = S (3) and Se (4), teta = triethylene-tetramine}, and [VIII2(en) 6 (μ 2 -O)][As 2 Se 5 ] (5) were solvothermally prepared and structurally characterized. The trigonal-pyramidal [As III Q 3 ] 3- anions in 1-4 act as η 2 -As III Q 3 chelating ligands to the unsaturated trivalent vanadium complex cations [V III (en/dap) 2 ] 3+ /[V III (teta)] 3+ , resulting in neutral molecules. 5 consists of a discrete saddle-like selenidoarsenate [As 2 Se 5 ] 4- anion built up from corner-sharing [AsSe 3 ] 3- trigonal pyramids and the dinuclear trivalent vanadium complex cation [VIII2(en) 6 (μ 2 -O)] 4- constructed through two [V III (en) 3 ] 3+ units bridged via one μ 2 -O group. The [V III (en) 3 ] 3+ unit contains two bidentate chelating en ligands and one monodentate en ligand, and offers a rare example of an en molecule as a monodentate ligand, because the en molecule usually exhibits the bidentate chelating coordinated mode. Emphatically, although some chalcogenoarsenates combined with transition metal complexes were isolated from chelating organic amine systems by a solvothermal reaction, no trivalent vanadium complex cations are involved in combination with the chalcogenoarsenates in this synthetic method to date. Therefore, 1-5 represent rare examples of hybrid chalcogenoarsenate(III) incorporating trivalent vanadium complexes. The absorption edges of 1-5 are in the energy range of 1.43-1.62 eV, and -they exhibit distinctive photocurrent response and photoconductive properties upon visible-light illumination.