Crystal and molecular structure of addition products of dimethyl acetylenedicarboxylate and N,N '-thiocarbanilyl hydrazine

The compound was synthesized from a reaction between N, N'-dithiocarbanilyl hydrazine and dimethyl acetylene dicarboxylate. X-ray diffraction analysis of one of the reaction products in two different solvents gave triclinic c rystals, [Space group= P (1) over bar, a= 13.273(8),Angstrom, b= 19.16(10), Angstrom, c= 10.965(4)Angstrom, alpha= 95.73(4)degrees beta= 90.86(4)degree s, gamma= 75.91(4)degrees, Z=4] and monoclinic crystals, [Space group= C2/c , a= 34.784(1)Angstrom, b= 13.119(1)Angstrom, c= 21.096(2)Angstrom, alpha= 90 degrees, beta= 91.72(1)degrees, gamma= 90 degrees, Z=16] respectively. T he carbo-methoxy in the triclinic form is cis to C = O in one molecule and trans in the other molecule while it is trans in both the molecules of the monoclinic form. There is a stacking of the five membered ring with phenyl rings in addition to the partial stacking between the five membered rings. The carbonyl groups point towards the centre of the heterocyclic five membe red rings mimicking the O4'... base interaction in Z - DNA. The structure i s stabilized by extensive intermolecular C-H . . .N, O-H . . .O and C-H . . .O hydrogen bonds. The solvent molecules also stabilize the packing of the molecules through hydrogen bonds.