5-Mercapto-1,3,4-thiadiazole-2(3H)-thione: Synthesis and Structure of Alkylated Derivatives

The observed structure of 1,3,4-thiadiazolidine-2,5-dithione (also known as 2,5-dimercapto-1,3,4-thiadiazole) has been previously reported in three different tautomeric forms including - dithiol and - dithione. This report examines the relative stability of each form and also reports synthesis and characterization of the structures of mono-alkylated and di-alkylated forms of 5-mercapto-1,3,4-thiadiazole-2(3H)-thione. The methods of X-ray crystallography, NMR spectroscopy, and ab initio electronic structure calculations were combined to understand the reactivity and structure of each compound