Prepns. of 2-(4-fluorobenzyl)-6-phenylimidazo[2,1-b][1,3,4]thiadiazole and its chlorophenyl deriv. were described. Preliminary anal. was done spectroscopically by means of 1H NMR, 13C NMR spectra, mass spectra and elemental analyses. Further the structures were confirmed by X-ray crystal structure analyses. The 4-fluorophenyl compd. crystd. in a triclinic P-1 space group with three independent mols. in the asym. unit, while the 4-chlorophenyl compd. belonged to P21/c space group with one mol. in the asym. unit. The imidazo-thiadiazole entity was as usual planar. Intramol. C-H···N hydrogen bonding between the imidazole and the Ph ring of the mol. was obsd. in both compds. The mols. of 4-fluorophenyl deriv. was linked into two dimensional supramol. hexagonal hydrogen bonded network sustained by C-H···F interaction, while those of 4-chlorophenyl deriv. was linked by bifurcated C-H···N interactions. Further, the mol. packing of both the compds. was stabilized by π-π stacking interactions between the benzene and imidazo-thiadiazole ring systems
