Kristallstruktur von β-VCl2(N3S2). Synthese und Kristallstruktur von [VCl(N3S2)(Pyridin)2]2·2 CH2Cl2, einem Cyclothiazenokomplex mit Vanadium(IV)/Crystal Structure of β-VCl2(N3S2). Synthesis and Crystal Structure of [VCl(N3S2)(pyridine)2]2·2 CH2Cl2, a Cyclothiazeno Complex with Vanadium (IV)

Abstract

Abstract β-VCl2(N3S2) was obtained by sublimation. It represents a new modification compared to the known α-VCl2(N3S2) which can be obtained from solution. Its crystal structure was determined by X-ray diffraction (864 observed reflexions, R = 0.034). Crystal data: triclinic, space group P1̄, Z = 2, a = 570.0, b = 779.9, c = 735.3 pm , α = 90.85°, β = 108.26°, y = 98.77°. Both modifications consist of polymer chains in which the vanadium atoms are linked alternatively by chloro and nitrogen bridges. The packing of the chains is rather similar, the only difference being that in β-VCl2(N3S2) the chains are rotated by 11° as compared to the orientation in α-VCl2(N3S2). The difference of the two modifications also shows up in the slightly different IR spectra. By reduction of VCl2(N3S2), dissolved in CH2Cl2/pyridine, with H2S, zinc or PPh3, the cyclothiazeno complex [VCl(N3S2)(pyridine)2]2·2 CH2Cl2 was obtained. It crystallizes in the monoclinic space group P 21/c, Z = 4, a = 1010.4, b = 917.3, c = 1967.8 pm, β = 103.03° (structure determination with 649 observed reflexions. R = 0.081). In this vanadium(IV) compound the metal atoms are part of planar VN3S2 rings as found in the VCl2(N3S2) modifications. The two vanadium atoms of the centrosymmetrical dimer are linked via one nitrogen atom of each of the VN3S2 rings; the resulting V2N2 ring is coplanar with the two VN3S2 rings.