Synthesis and solid state characterization of two insoluble tetrathiometalates

Abstract

The aqueous reaction of ammonium tetrathiometalates (NH4)2[MS4] (M = Mo or W) with (dbtmen)Br2 · 2H2O (dbtmen = N,N′-dibenzyl-N,N,N ′, N′-tetramethylethylenediammonium dication) results in the formation of the highly insoluble compounds (dbtmen)[MoS4] (1) and (dbtmen)[WS4] (2) in near quantitative yields. Compounds (1) and (2) have been characterized by elemental analysis, spectroscopic methods, X-ray powder diffraction and TG–DTA. Both compounds exhibit nearly identical IR spectra and X-ray powder patterns. The compounds exhibit a single strong signal for the asymmetric M–S stretching vibration at 475 cm−1 in (1) and at 457 cm−1 in (2). Complex (2) is thermally more stable than the corresponding Mo analogue (1). Thermal decomposition products of (1) and (2) are carbon contaminated amorphous metal disulfides and are formulated as MoS1.99C2.06N0.07 and WS1.75C3.02 based on elemental analysis of the residue.