Vibrational Spectroscopic Study of (E)-4-(Benzylideneamino)-N-Carbamimidoyl Benzenesulfonamide

The Fourier transform infrared and Fourier transform Raman spectra of (E)-4-(benzylideneamino)-N-carbamimidoyl benzenesulfonamide were recorded and analyzed. Geometry and harmonic vibrational wavenumbers were calculated theoretically using Gaussian 03 set of quantum chemistry codes. Calculations were performed at the Hartree-Fock (HF) and density functional theory (DFT; B3PW91, B3LYP) levels of theory. The calculated wavenumbers (B3LYP) agree well with the observed wavenumbers. Potential energy distribution is done using GAR2PED program. The red shift of the N-H stretching band in the infrared spectrum from the computed wavenumber indicates the weakening of the N-H bond. The geometrical parameters of the title compound are in agreement with that of reported similar derivatives. The calculated first hyperpolarizability is comparable with the reported value of similar derivative and may be an attractive object for further studies of nonlinear optics. Potential energy surface scan studies have been carried out to understand the stability of planar and nonplanar structures of the molecule.