An International Research Journal

AJP

SSN : 0971 - 3093

Vol  15, No 2, April-June, 2006

Asian Journal of Physics                                                                                                        Vol. 15, No 2 (2006) 281-285


Predicting wavenumbers of vibrational spectra, its use in spectroscopy


M A Palafoxa, G Tardajosa, J J Kimb, O F Nielsenc, Rajive Lodhid, V K Rastogid
aDepartamento de Quimica-Fisica I, Facultad de Ciencias Ouimicas,Universidad Coinplutense. Madrid-28040, Spain

bDepartment of Physics. Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu,Daejon.305-701, Republic of Korea.

cChemical Institute. University of Copenhagen. 5- Universitetsparken, DK-2100,Copenhagen, Denmark.
dPhysics Department, CCS University, Meerut-250004. India

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For the wavenumber calculations, many Quantum Chemical methods are available today, implemented in a large variety of programme packages. The present communication gives a brief resume of the results obtained for some compounds of medium size, and the accuracy reached with them. It is concluded that the basis set has little influence, but the 6-31G* and 6-310** have the most adequate cost-effective relationship. © Anita Publication All right reserved.

Predicting wavenumbers of vibrational spectra, its use in spectroscopy.pdf
M A Palafox, G Tardajos, J J Kim, O F Nielsen, Rajive Lodhi, V K Rastogi

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Asian Journal of Physics                                                                                                        Vol. 15, No. 2 (2006)287-296


Theoretical and spectroscopic studies of 3,5-pyrazoledicarboxylic acid and its new La(III) complex


Irena Kostova1, Niculina Peica2, Rajive Lodhi3 and V K Rastogi3

1Department of Chemistry, Faculty of Pharmacy, Medical University, 2 Dunav St., Sofia 1000, Bulgaria
2Institui fur Physikalische Chemie, Universitat Wurzburg,Am Hubland, 97074 Wiirzburg, Germany
3Department of Physics, CCS University, Meerut- 250 004, India

(Dedicated to Professor Wolfgang Kiefer on the occasion of his 65th birthday)

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The complex of lanthanum (III) was synthesized by reaction of the respective inorganic salt with 3,5-pyrazoledicarboxylic acid in amounts equal to metal: ligand molar ratio of 1:2. The composition and the structure of the final complex was determined by means of spectral and elemental analyses. Significant differences in the IR and Raman spectra of the complex were observed as compared to the spectra of the ligand. The comparative vibrational analysis of the free ligand and its La(III) complex gave evidence that 3,5-pyrazoledicarboxylic acid bounds the La(III) through the deprotonated carboxylic oxygens. The DFT calculated geometries, harmonic vibrational modes and Raman scattering activities for the ligand were in good agreement with the experimental data, a complete vibrational assignment being proposed. The experimental IR and Raman bands of the ligand were assigned to normal modes on the basis of DFT calculations. The effect of the intramolecular H-bonds in the ligand on vibrational mode positions was also discussed. The characteristic IR and Raman bands of 3,5-pyrazoledicarboxylic acid and its lanthanum complex were specified and discussed. © Anita Publications. All rights reserved.

Total Refs : 68

Theoretical and spectroscopic studies of 3,5-pyrazoledicarboxylic acid and its new La(III) complex.pdf
Irena Kostova, Niculina Peica, Rajive Lodhi and V K Rastogi

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