Conformational study of S-alkylated isothiosemicarbazones

Abstract

A theoretical investigation of the conformational preferences of S-alkylated isothiosemicarbazones was performed. The structures of such compounds cluster in two groups, according to the different orientation of the —SR group with respect to the hydrazine N atom of the thiosemicarbazide. While the trans arrangement may be more stable for the isolated molecules, owing to N—H...N intramolecular interactions, the cis form is preferred by most compounds in the solid state, as the result of interplay between intra- and intermolecular effects.