Popis: |
The 1,5-diaryl-3-cyanoformazans were prepared and subjected to IR, MS,1H NMR, and13C NMR spectral analysis. The results indicate the presence of a strong intramolecular hydrogen bond in the formazan molecule. Moreover, the two phenyl rings are equivalent and the CN and NH stretching vibrational modes are slightly affected with electron-withdrawing substituents and interact with the neighboring CC stretching mode. Thesyn, s-cisformazan form was supported by calculating the frequencies, normal coordinate analysis, force constant refinement, and group theory treatment. High quality of fitting between the experimental and calculated frequencies with all formazans has been achieved. |