Showing papers by "Hema Tresa Varghese published in 2012"
TL;DR: The first hyperpolarizability is comparable with the reported values of similar derivatives and is an attractive object for future studies of non linear optics.
55 citations
TL;DR: The variations in the CN bond lengths of the title molecule suggest an extended π-electron delocalization over the sulfaguanidine moiety which is responsible for the nonlinearity of the molecule.
37 citations
TL;DR: The results indicate that B3LYP method is able to provide satisfactory results for predicting vibrational frequencies and structural parameters and is an attractive object for future studies of non-linear optics.
36 citations
TL;DR: A computation of the first hyperpolarizability of the compound indicates that the compound may be a good candidate as a NLO material.
30 citations
TL;DR: In this article, the harmonic vibrational wavenumbers of 4-nitropyrocatechol were calculated theoretically using Gaussian03 software, using the standard 6-31G* basis.
Abstract: The IR and Raman spectra of 4-nitropyrocatechol have been recorded and analyzed. The harmonic vibrational wavenumbers were calculated theoretically using Gaussian03 software. Calculations were performed by the DFT level using the standard 6-31G* basis. The calculated wavenumbers agree well with the observed wavenumbers. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands found in the IR and Raman spectra of the title compound. The predicted infrared intensities and Raman activities are reported.
15 citations
TL;DR: In this paper, the FTIR and FT-Raman spectrum of 5,benzo-1,3,benzodioxole were recorded and analyzed theoretically using the Gaussian03 set of quantum chemistry codes.
Abstract: FTIR and FT-Raman spectrum of 5,-benzo-1,3-benzodioxole were recorded and analyzed. The vibrational wavenumbers were examined theoretically using the Gaussian03 set of quantum chemistry codes. The experimental frequencies are in agreement with the calculated (B3LYP) scaled values. The predicted infrared intensities and Raman activities are reported.
8 citations
TL;DR: In this paper, the Fourier transform infrared spectra of (E)-4-(benzylideneamino)-N-carbamimidoyl benzenesulfonamide were recorded and analyzed.
Abstract: 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.
8 citations
TL;DR: The calculated first hyperpolarizability is comparable with the reported values of similar derivatives and is an attractive object for future studies of nonlinear optics.
8 citations
TL;DR: In this article, the FTIR and FT-Raman spectrum of 5,6-benzo-2-pyrone were analyzed theoretically using the Gaussian03 set of quantum chemistry codes and the experimental frequencies were in agreement with the calculated (B3LYP) scaled values.
Abstract: FTIR and FT-Raman spectrum of 5,6-benzo-2-pyrone were recorded and analyzed. The vibrational wavenumbers were examined theoretically using the Gaussian03 set of quantum chemistry codes. The experimental frequencies are in agreement with the calculated (B3LYP) scaled values. The phenyl and pyrone ring modes are identified and assigned. The predicted infrared intensities and Raman activities are reported.
4 citations
01 Jan 2012
TL;DR: In this article, the SDD method was used for predicting the vibrational wavenumbers of Salicylohydrazide and the predicted infrared intensities and Raman activities were reported.
Abstract: IR and Raman spectra of Salicylohydrazide were recorded and analyzed. Using Gaussian03 set of quantum chemistry codes, the vibrational wavenumbers and corresponding vibrational assignments were examined theoretically. The results indicate that the SDD method is able to provide satisfactory results for predicting the vibrational wavenumbers. The predicted infrared intensities and Raman activities are reported.