Synthesis and structural characterization of bis(dimethylammonium) tetrasulfidometalates

Abstract

Reaction of (NH(4))(2)[MS(4)] (M = Mo, W) with aqueous dimethylamine (CH(3))(2)NH or KOH results in the formation of bis(dimethylammonium) tetrasulfidometalates [(CH(3))(2)NH(2)](2)[MS(4)] (M = W 1; Mo 2) or dipotassium tetrasulfidotungstate K(2)[WS(4)] (3). Compounds 1-3 were characterized by elemental analysis, IR and UV-Vis spectra and their crystal structures were determined. Compounds 1 and 2 are isostructural and crystallize in the centrosymmetric monoclinic space group P2(1)/n. The structures consist of two crystallographically independent dimethylammonium cations and a slightly distorted tetrahedral [MS(4)](2-) anion with all atoms situated in general positions. The cations and anions are involved in several weak N-H...S and C-H...S interactions. Compound 3 crystallizes in the centrosymmetric orthorhombic space group Pnma and is isostructural with the previously reported K(2)[MoS(4)]. The structure of 3 consists of discrete slightly distorted tetrahedral [WS(4)](2-) anions of m symmetry, separated by two crystallographically independent K(+) cations located on mirror planes. A comparative description of the alkali metal, ammonium, methyl and dimethylammonium tetrasulfidometalates is presented.