This shift related to the absorption intensity confirms the contribution of ν(S=O) group that coordinates with metal via oxygen atom. Stretching peak corresponding to C-F bond stay unaffected which is found in the range of 1116-1127 cm -1 in the spectra of the compounds as fluorine atoms do not take part in the formation of the complexes. A precise peak was observed at 1465 cm -1 in free ligand which is allotted for the stretching frequency of (>C-N-) in benzimidazole ring. This >C-N-vibration in the complexes, shows up like a low intensity peak near 1415-1446 cm -1 . The formation of >C-N-→M(II) bond is confirmed by the reduction of this stretching frequency. Azomethine group, (-C=N-) with stretching frequency of 1585 cm -1 corresponding to ligand, remains unaltered in complexes. Characteristic band ascribed for the existence of water emerges in the form of weak distinct band near 3324-3385 cm -1 . This indicates the presence of water molecules bound to the compound. Conversely, in that region, zinc compound which was found as an anhydrous compound does not illustrate absorption peak.