Crystal and molecular structure of 2-thiobenzylazobenzene (C 19 H 16 N 2 S)

The title compound (I, W=X=Y=H, Z = CH2Ph) is a divalent organosulphur compound of the type Ar-S-Z belonging to the class of ortho mercaptoazo compounds. The azo group is moved away from the sulphenyl sulphur atom to attain the stable trans azo configuration. The sulphur atom has used hybrid orbitals (sp3) and not pure p-orbitals for the bond formation. The benzyl units attached to the sulphenyl sulphur and the 2-benylazo unit are moved away from each other for steric reason. The molecule is as a whole non-planar but N1 and N2 atoms are coplanar with the respective phenyl rings to which they are attached. The S 1 atom is coplanar with the phenyl group to which it is attached. The dihedral angle between the mean planes passing through the atoms of the thiophenyl group and the benzyl group is 75(1)°. There is no intermolecular hydrogen bond and the molecule is stabilised by the network of Van der Waal's interaction in their crystalline assembly.