Synthesis, crystal structure study and spectroscopic analysis of substituted 2,3-dihydro-2-thioxo-4H-1,3,5-thiadiazin-4-ones

A variety of substituted 2,3-dihydro-2-thioxo-4H-1,3,5-thiadiazin-4-ones was synthesized from carbonyl diisothiocyanate and different nucleophiles, like water, alcohols, thiols, and amines. A comprehensive crystal structure analysis of the resulting thiadiazines is presented together with analysis of their nuclear magnetic resonance and infrared spectra. The central thiadiazine motif of each molecules forms a planar albeit slightly irregular hexagon. Independent of the substituent, all molecules form dimers in the solid state which are held together via hydrogen bonds. Hirshfeld surface analysis shows mostly short polar interactions, with increasing non-polar interactions depending on the size of the side chain.