Crystal structure study of 2-phenyliminothiazolidines

A series of 2-phenyliminothiazolidines has been successfully synthesized; a nd 2-(2-methylphenyl)iminothiazolidine(I a) and 2-(4-methylphenyl) iminothi azolidine( I b) have been selected to determine their crystal structures by X-ray diffraction technique, from their molecular graph of it is shown tha t double bond at 2-carbon atom of the heterocycle is all extro-cyclic at: t he crystal state, and there are two main plaines in I a and I b. But in I a , the angle between the planes is 61.4 degrees and in I b the angle is abou t 41.4 degrees. And so there is a strong conjugative effect in I b than in I a. So it is thought that the difference in fungicidal activities between 8-substitutedphenyl compounds (I a) and 4-substitutedphenyl compounds( I b) is due to their space factors.