A Crystallographic, Spectroscopic, and Computational Investigation of Carbonyl and Oxalyl Diisothiocyanate.

Carbonyl diisothiocyanate (1) and oxalyl diisothiocyanate (2) were synthesized by reactions of phosgene and oxalyl chloride with ammonium thiocyanate, respectively. Their structures were elucidated by single-crystal X-ray diffraction. 1 exhibits weak intermolecular S-O contacts forming a loosely connected network of molecules, whereas 2 exhibits weak intermolecular Ccarbonyl-O contacts resulting in the formation of layers. Both compounds were further characterized by nuclear magnetic resonance, infrared, and Raman spectroscopy. Quantum-chemical calculations reproduced the experimental structures and enabled the interpretation of the vibrational spectra.