Synthesis and structure of dithiocarbonimidates derived from aromatic heterocycles: Role of weak interactions in the preferred conformation

The synthesis and the structure of four dimethyldithiocarbonimidates: 1-methyl-2-dimethyldithiocarbonimidate-benzimidazole (1), 5-chloro-2-[dimethyldithiocarbonimidate]-benzoxazole (2), 1-methyl-2-[dimethyldithiocarbonimidate]-pyrimidinium iodide (3) and 1,4-dimethyl-6-oxo-2-[dimethyldithiocarbonimidate]-pyrimidine (4), were investigated by TOF mass spectra, NMR and X-ray diffraction analyses. It was found that the molecules were planar with preferred conformations dictated by intramolecular N → S interactions. In the crystals, dimers or polymers were stabilized through S⋯S, S⋯π and CH⋯Y (Y = S, O, N and π electrons) interactions. Calculations confirmed the weak interactions.