The Experts below are selected from a list of 141 Experts worldwide ranked by ideXlab platform
S. Mohan - One of the best experts on this subject based on the ideXlab platform.
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ft ir and ft raman spectra and Normal Coordinate Analysis of poly methyl methacrylate
Der Pharma Chemica, 2010Co-Authors: Mas Rosemal Hakim Mas Haris, S Kathiresan, S. MohanAbstract:Poly methyl methacrylate (PMMA) is a widely used polymer with various applications. Fourier transform infrared and Raman spectra of PMMA were recorded in range of 4000 – 400 cm-1 and 4000 – 100 cm-1, respectively. In the present investigation, detailed assignments of the observed fundamental bands of PMMA have been analyzed in terms of peak positions and relative intensities. With hope of providing more and effective information on the fundamental vibrations, a Normal Coordinate Analysis has also been performed on PMMA by assuming Cs symmetry. The simple general valence force field (SGVFF) has been employed in Normal Coordinate Analysis and the potential energy distribution (PED) has been calculated for each fundamental vibration. The PED contribution corresponding to each of the observed frequencies shows the reliability and accuracy of spectral Analysis.
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vibrational spectra assignments and Normal Coordinate Analysis of 3 aminobenzyl alcohol
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2003Co-Authors: N Sundaraganesan, H Saleem, S. MohanAbstract:Abstract The laser Raman and FTIR spectra of 3-aminobenzyl alcohol have been recorded. The observed frequencies were assigned to various modes of vibrations on the basis of Normal Coordinate Analysis, assuming Cs point group symmetry. The potential energy distribution associated with Normal modes is also reported here. The assignment of fundamental vibrations agrees well with the calculated frequencies.
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Vibrational spectra and Normal Coordinate Analysis of carbamoylazide.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2003Co-Authors: S. Mohan, K.s.p. Durairaj, Sujin P. JoseAbstract:Abstract The Fourier transform Raman and infrared spectra of carbamoylazide and its deuterated derivative were recorded and the observed frequencies were assigned to various modes of vibration in terms of fundamentals and combinations by assuming Cs point group symmetry. A Normal Coordinate Analysis was also carried out using Simple valence force field. A complete vibrational Analysis is presented here for these molecule and results are briefly discussed.
S. Gunasekaran - One of the best experts on this subject based on the ideXlab platform.
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Vibrational spectra and Normal Coordinate Analysis of diethyl carbamazine
Indian Journal of Pure & Applied Physics, 2009Co-Authors: S. Gunasekaran, B. AnitaAbstract:A Normal Coordinate Analysis has been carried out for diethyl carbamazine using the vibrational frequencies observed in the FTIR and FTRaman spectra. An orthoNormal set of symmetry Coordinates has been constructed and Wilson’s F-G matrix method has been used for Normal Coordinate Analysis. A satisfactory vibrational band assignment has been made for the molecule in terms of Normal modes of vibration using FTIR and FTRaman spectroscopy. A reasonable set of potential constants evaluated for the molecule is found to be in good agreement with the previous studies, thereby confirming the vibrational assignments. Further, to check whether the chosen set of vibrational frequencies contributes maximum to the potential energy associated with the Normal Coordinates of the molecule, potential energy distribution has been calculated .
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spectral investigation and Normal Coordinate Analysis of piperazine
Indian Journal of Pure & Applied Physics, 2008Co-Authors: S. Gunasekaran, B. AnitaAbstract:Piperazine is a secondary amine with the molecular formula C 4 N 2 H 12 . A Normal Coordinate Analysis (NCA) has been carried out on this molecule with a systematic set of symmetry Coordinates following Wilson's F-G matrix method based on D 2h , point group symmetry. The frequency assignments in the FTIR and FTR spectra have been presented. A reasonable set of potential constants evaluated for this molecule has been compared with those of related molecules and are in the characteristic range. The potential energy distribution has been evaluated using the vibrational spectral data. The potential energy distribution value obtained reflects the correctness of the assignment made.
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vibrational spectra and Normal Coordinate Analysis on structure of nitrazepam
Indian Journal of Pure & Applied Physics, 2008Co-Authors: S. Gunasekaran, S Seshadri, R Arunbalaji, S MuthuAbstract:A Normal Coordinate Analysis on nitrazepam has been carried out with a set of symmetry co-ordinates following Wilson's F-G matrix method. The potential constants evaluated for the molecule are found to be in good agreement with literature values thereby conforming the vibrational assignments. To check whether the chosen set of vibrational frequencies contributes maximum to the potential energy associated with the Normal co-ordinates of the molecule, the potential energy distribution has been evaluated.
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vibrational spectra and Normal Coordinate Analysis of diazepam phenytoin and phenobarbitone
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2006Co-Authors: S. Gunasekaran, Thilak R Kumar, S PonnusamyAbstract:Abstract Vibrational spectroscopy is an important tool for the structural investigation of the organic molecules. In the present investigation, a Normal Coordinate Analysis has been carried out on some anti-epileptic drugs, viz. diazepam, phenytoin and phenobarbitone. Diazepam is a derivative of benzodiazepine, phenytoin is a derivative of hydanation and pheonobarbitone is a barbiturate. The infrared spectra of the compounds are recorded in the region 4000–400 cm −1 and Raman spectra are recorded in the region 3500–50 cm −1 . From the structural point of view, diazepam, phenytoin and phenobarbitone have been assumed to C s point group. A systematic set of symmetry Coordinates has been constructed for these compounds and Wilson's FG matrix method has been applied for the Normal Coordinate Analysis using general quadratic valance force field. The potential energy distribution is also calculated to check the vibrational band assignments.
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vibrational spectra and Normal Coordinate Analysis of flucytosine
Indian Journal of Pure & Applied Physics, 2006Co-Authors: S. Gunasekaran, S Seshadri, S MuthuAbstract:A Normal Coordinate Analysis on flucytosine has been carried out with a systematic set of symmetry Coordinates following Wilson’s F-G matrix method. The potential constants evaluated for the molecule are found to be in good agreement with literature values thereby confirming the vibrational assignments. To check whether the chosen set of vibrational frequencies contributes maximum to the potential energy associated with the Normal Coordinates of the molecule, the potential energy distribution has been evaluated.
Robert E Rosenberg - One of the best experts on this subject based on the ideXlab platform.
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infrared intensities cyclobutene a Normal Coordinate Analysis and comparison with cyclopropene
The Journal of Physical Chemistry, 1992Co-Authors: Kenneth B Wiberg, Robert E RosenbergAbstract:The infrared and Raman spectra of cyclobutene and of its 1,2-d 2 and 3,3,4,4-d 4 isotopomers were determined, and the intensities of the infrared bands were measured. A new vibrational assignment was made with the help of the spectrum calculated using the 6-31G * basis set. A Normal-Coordinate Analysis was carried out, and the infrared intensities were converted to atomic polar tensors and to dipole moment derivatives with respect to symmetry Coordinate
Kenneth B Wiberg - One of the best experts on this subject based on the ideXlab platform.
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infrared intensities cyclobutene a Normal Coordinate Analysis and comparison with cyclopropene
The Journal of Physical Chemistry, 1992Co-Authors: Kenneth B Wiberg, Robert E RosenbergAbstract:The infrared and Raman spectra of cyclobutene and of its 1,2-d 2 and 3,3,4,4-d 4 isotopomers were determined, and the intensities of the infrared bands were measured. A new vibrational assignment was made with the help of the spectrum calculated using the 6-31G * basis set. A Normal-Coordinate Analysis was carried out, and the infrared intensities were converted to atomic polar tensors and to dipole moment derivatives with respect to symmetry Coordinate
V. Krishnakumar - One of the best experts on this subject based on the ideXlab platform.
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Vibrational and Normal Coordinate Analysis of thymine hydrochloride
Indian Journal of Pure & Applied Physics, 2003Co-Authors: V. Krishnakumar, M. ArivazhaganAbstract:The FTIR and laser Raman spectra of thymine hydrochloride were recorded in the region 4000-100 cm - 1 and the Normal Coordinate Analysis has been carried out by assuming Cs point group symmetry. All the Normal modes of vibrations are assigned and calculations of potential energy distribution are also performed.
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Spectral and Normal Coordinate Analysis of 5,6-dihydro-5-methyl uracil
Indian Journal of Pure & Applied Physics, 2003Co-Authors: V. Krishnakumar, R RamasamyAbstract:The FTIR spectrum of 5,6-dihydro-5-methyl uracil has been recorded in the region 4000-100 cm - 1 and the Normal Coordinate Analysis has been carried out by assuming C, point group symmetry. All the Normal modes of vibrations are assigned and calculations of potential energy distribution are also performed.
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Normal Coordinate Analysis of 2 mercapto and 4 6 dihydroxy 2 mercapto pyrimidines
Indian Journal of Pure & Applied Physics, 2003Co-Authors: V. Krishnakumar, John R XavierAbstract:The FTIR spectrum of 2-niercapto pyrimidine has been recorded in the region 4000-50 cm - 1 and Normal Coordinate Analysis of 2-mercapto pyrimidine and 4,6-dibyctroxy-2-mercapio pyrimidine has been carried out by assuming Cs point group symmetry. All the modes of vibrations are assigned and calculations of potential energy distributions are also performed.
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spectral and Normal Coordinate Analysis of 6 methoxy purine
Indian Journal of Pure & Applied Physics, 2002Co-Authors: V. Krishnakumar, R RamasamyAbstract:The FTIR spectrum of 6-methoxy purine has been recorded in the region 4000-100 cm - 1 and the Normal Coordinate Analysis has been carried out by assuming C s point group symmetry. All the Normal modes of vibrations are assigned and calculations of potential energy distribution are also performed.
