Thermal and spectroscopic investigations of organic ammonium tetrathiotungstates

Abstract

Ethylenediammonium tetrathiotungstate, (enH2)[WS4] 1, 1,3-propanediammonium tetra-thiotungstate (1,3-pnH2)[WS4] 2, N,N,N′,N′-tetramethylethylenediammonium tetrathio-tungstate (tmenH2)[WS4] 3 and 1,4-dimethylpiperazinium tetrathiotungstate, (1,4-dmpH2)[WS4] 4 were prepared by reacting an aqueous solution of (NH4)2[WS4] with the corresponding organic diamines. The complexes 1-4 were characterized by elemental analysis, IR, UV-Vis and TG-DTA methods. On heating, compounds 1, 2 and 4 decompose in a single step while 3 decomposes in two closely related steps. Elemental analysis, X-ray and ESEM techniques have been used for the characterization of the final thermolysis products. The compounds 1-4 decompose at higher temperatures to form carbon contaminated amorphous tungsten disulfides.