Synthesis, properties, and structure of 1,3-dimethyl-2(3H)-imidazolethione hydrogen bromide

The compound dmit·HBr (dmit=1,3-dimethyl-2(3H)-imidazolethione) has been synthesized and characterized. The crystal and molecular structure of dmit·HBr has also been determined. The compound, C5H9BrN2S, crystallizes in space groupP21/c with four formula units in a cell of dimensionsa= 7.331(1),b=7.744(2),c=14.626(4) Å, andß=99.56(2)°. The calculated and observed densities are 1.678 and 1.68(2) g cm-3, respectively. X-ray results along with physical characterization show this compound to be a molecular adduct of dmit and hydrogen bromide which is sensitive to air, light, and moisture. Specific conductivity (10-3 M in PhNO2), infrared, and1H-NMR data have also been obtained. X-ray results reveal intermolecular contracts between S and Br to be primarily van der Waals in nature. Molecular units are linked through long zigzag Br-S-Br-S chains.