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Bhagyasree J.B.,Mar Ivanios College | Varghese H.T.,Fatima Mata National College | Samuel J.,Mar Ivanios College | Van Alsenoy C.,University of Antwerp | And 3 more authors.
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy

The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of 5-nitro-2-(4-nitrobenzyl) benzoxazole have been investigated experimentally and theoretically using Gaussian09 software package. Potential energy distribution of the normal modes of vibrations was done using GAR2PED program. The energy and oscillator strength calculated by time dependent density functional theory almost compliments with experimental findings. Gauge-including atomic orbital 1H NMR chemical shifts calculations were carried out by using B3LYP functional with 6-31G- basis set. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization have been analyzed using NBO analysis. MEP was performed by the DFT method and the predicted infrared intensities and Raman activities have also been reported. The calculated geometrical parameters are in agreement with that of similar derivatives. © 2012 Elsevier B.V. All rights reserved. Source

Anto P.L.,Thomas College | Varghese H.T.,Fatima Mata National College | Philip D.,Mar Ivanios College
Journal of Raman Spectroscopy

The Fourier-transform infrared and Fourier-tranform Raman spectra of phenyl phosphate disodium salt were recorded and analyzed. The surface-enhanced Raman scattering (SERS) spectrum was recorded in a silver colloid. The vibrational wavenumbers of the compound were computed using the Hartree-Fock/6-31G* basis and compared with the experimental values. The molecule is adsorbed on the silver surface with the benzene ring in a tilted orientation. The presence of the phenyl ring and the phosphate group vibrations in the SERS spectrum reveal the interactions between the phenyl ring and the phosphate group with the silver surface. The first hyperpolarizability is calculated, and the calculated molecular geometry is compared with those of similar reported structures. Copyright © 2009 John Wiley & Sons, Ltd. Source

Varghese H.T.,Fatima Mata National College
Oriental Journal of Chemistry

The C=O stretching frequencies of compounds containing carboxylic group are calculated theoretically using Gaussian03 software at the density functional level and compared with experimental values. The C=O bond lengths are also nearly same for all compounds. The nature of substitution in the molecules affect the C=O stretching frequencies. The in-plane OH deformation bands and C-O stretching frequencies are also found to be in agreement with the theoretical results. Source

Sarlin P.J.,Cochin University of Science and Technology | Sarlin P.J.,Fatima Mata National College | Philip R.,Cochin University of Science and Technology

Efficacy of marine yeasts Debaryomyces hansenii (S8) and Candida tropicalis (S186) as immunostimulants to Indian white prawn Fenneropenaeus i. ndicus was estimated in comparison with Saccharomyces cerevisiae S36. Biomass of yeast strains was prepared using Malt Extract Agar and incorporated into a standard diet to prepare yeast diets of varying concentrations. F. indicus were fed these diets for a period of 14. days and then challenged orally with white spot syndrome virus (WSSV) and immune assays like total hemocyte count, phenol oxidase, NBT reduction, alkaline phosphatase and acid phosphatase were performed. Generally yeast diets provided better protection to F. indicus against WSSV compared to control. Marine yeast diet was found to support maximum immunostimulation evidenced by enhanced shrimp immunity. The study showed that marine yeasts D. hansenii (S8) and C. tropicalis (S186) are effective immunostimulants in F. indicus and they perform better than the baker's yeast, S. cerevisiae. © 2011 Elsevier B.V. Source

Raj A.,Government Polytechnic College | Raj A.,Kerala University | Mary Y.S.,Fatima Mata National College | Varghese H.T.,Fatima Mata National College | Raju K.,Kerala University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy

(Figure Presented) FT-IR and FT-Raman spectra of 2-(benzylsulfanyl)-3,5- dinitrobenzoic acid were recorded and analyzed. SERS spectra were recorded in silver colloid, silver electrode and silver substrate. The vibrational wave-numbers were computed using HF and DFT quantum chemical calculation methods. The data obtained from wavenumber calculations are used to assign vibrational bands obtained in infrared and Raman spectra as well as in SERS of the studied molecule. Potential energy distribution was done using GAR2PED program. The geometrical parameters of the title compound are in agreement with the reported similar derivatives. The presence of phenyl ring modes in the SERS spectra suggests a tilted orientation with respect to the metal surface in all cases. In all the three SERS spectra the NO2 moiety shows an enhancement, which indicates the interaction with the metal surface. The first hyperpolarizability is high and the title compound is an attractive object for future studies of nonlinear optics. © 2013 Elsevier B.V. All rights reserved. Source

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