Structure and thermal behaviors of organic crystals based on substituted 1,3,4-thiadiazoles

Abstract The crystalline structure of some compounds containing the 1,3,4-thiadiazole moiety, ( 1 ) 5-ethyl-2-amino-1,3,4- thiadiazole (EATZ), ( 2 ) 5-benzylsulfany-2-amino-1,3,4-thiadiazole (BSATZ) and ( 3 ) 2,5-bis-benzylsulfanyl-1,3,4-thiadiazole (BBSTZ) were determined. Both EATZ and BBSTZ show orthorhombic structures with space group Pbca and BSATZ a monoclinic system with space group C2/c. The lattice parameters: a =0.72280 (14), b =1.0811 (2), c =1.6210 (3) nm for 1 , a =2.5282 (5), b =0.59083 (12), c =1.5390 (3) nm for 2 and a =0.87530 (18), b =1.0365 (2), c =3.6098 (7) nm for 3 . To compare the intra- and intermolecular interactions in thiadiazole containing organic crystals, thermal analysis studies on each crystal is performed using DSC and TG in N 2 atmosphere to describe the thermal behaviors. Based on the results, the changing regularity of melting point and decomposition temperature of these compounds is educed