Synthesis, Crystal Structure and Biological Activity of 2-(Anthracen-9-yl)-5-p-tolyl-1,3,4-oxadiazole

A novel compound, 2-(anthracen-9-yl)-5-p-tolyl-1,3,4-oxadiazole (C23H16N2O), has been synthesized by the condensation of 4-methylbenzohydrazide and anthracene-9-carbaldehyde in an ethanol solution with chloramine-T. The compound was characterized by H-1-NMR, C-13-NMR, MS and single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P (1) over bar with a = 7.7817(4), b = 8.8544(5), c = 12.4726(8) angstrom, beta = 92.8520(10)degrees, Z = 2, V = 826.58(8) angstrom(3), D-c = 1.352 g/cm(3), M-r = 336.38, lambda(MoK alpha) = 0.71073 angstrom, mu = 0.084 mm(-1), F(000) = 352, R = 0.0381 and wR = 0.1099. The dihedral angle between anthracene skeleton and phenyl ring is 64.19 degrees. A total of 6354 unique reflections were collected, of which 3172 with I > 2 sigma(I) were observed. X-ray analysis indicated an offset face-to-face pi-pi stacking interaction between anthracene skeletons and an offset face-to-face pi-pi stacking interaction between phenyl ring planes. The novel compound molecules are connected through the offset face-to-face pi-pi stacking interactions to generate a three-dimensional network. The preliminary bioassay results showed that the novel compound exhibited significant insect growth inhibitory activity against Spodoptera litura Fabricius larvae.