Structure of 5,5-dimethyl-2-phenylimino-Δ3-1,3,4-thiadiazoline from oxidative cyclization of a thiosemicarbazone
The X-ray crystal structure of 5,5-dimethyl-2-phenylimino-Δ3-1,3,4-thiadiazoline, C10H11N3S, has been determined. The compound is monoclinic, P21/c (No. 14), with a = 13.200(5), b = 6.340(4), and c = 13.823(4) Å, β = 113.50(4)°, and Z = 4. The structure was determined by direct methods and refined to R = 0.061, Rw = 0.067 for 1277 unique reflections. The molecule has the Z configuration. The thiadiazoline ring is planar. C—N and N=N bond lengths are within the normal range. The C—S bond lengths are similar to those we have observed previously in thiazolidines. Angles differ markedly from an expected average 108°. The small C—S—C angle (90.6(2)°) is accompanied by larger C—N=N angles (114.9(3), 117.8(3)°). The phenyl ring is not coplanar with the thiadiazoline ring (dihedral angle 38.6(4)°) because of repulsive interaction of the phenyl o-hydrogen atom with the sulphur atom.