Crystal Structure and Solid-State Packing of 4-Chloro-5 H -1,2,3-dithiazol-5-one and 4-Chloro-5 H -1,2,3-dithiazole-5-thione.

The crystal structure and solid-state packing of 4-chloro-5-1,2,3-dithiazol-5-one and two polymorphs of 4-chloro-5-1,2,3-dithiazole-5-thione were analyzed and compared to structural data of similar systems. These five-membered S,N-rich heterocycles are planar with considerable bond localization. All three structures demonstrate tight solid-state packing without voids which is attributed to a rich network of short intermolecular electrostatic contacts. These include S…N, S…O, S…Cl and S…S interactions that are well within the sum of their van der Waals radii (∑). B3LYP, BLYP, M06, mPW1PW, PBE and MP2 were employed to calculate their intramolecular geometrical parameters, the Fukui condensed functions to probe their reactivity, the bond order, Bird Index and NICS(1) to establish their aromaticity.