Abstract: 3(1-Naphthylmethylene)-6-hexye-s-triazolo[3,4-b]-1,3,4-thiadiazole was synthesized by condensation of 3(1-naphthyl-methylene)-4-amino-5-mercapto^-1,2,4-triazoIe with n-heptanoic acid in the medium of phosphorus oxychloride.The single crystal structure of this new compound was determined by X-ray analysis.The crystal belongs to monoclinic system with a space group C₂/C, a=2.8680(6) nm, 6=0.8356(2) nm, c=1.6578(3) nm, β=114.19(2)°, V=3.624 nm³, M=350.49, Z=8, D_x=1.29 g/cm³, U=1.80 cm^-1, F(000)=744, R=0.071.The most important information obtained from analyzing the crystal structure is that, in comparision with normal N-N, C-Nand C-S, each of the single bond lengthes of N(23)-N(24), C(22)-N(26) and C(25)-Sin this compound is smaller than the normal bond length, but those for all C=Nbond show remarkable lengthening effect of 0.003 nm(2.3%).All the above results indicate that the s-triazolo [3,4-b]-1,3,4-thiadiazole is planar, confirming the atom character of 10-π electron system.

Key words: s-Triazolo[3,4-b]-1,3,4-thiadiazole, Synthesis, Crystal structure