Ab initio/DFT electronic structure calculations, spectroscopic studies and normal coordinate analysis of 2-chloro-5-bromopyridine

Tom Sundius, C.S. Hiremath, Jayashree Yenagi

Research output: Contribution to journalArticleScientificpeer-review

Abstract

FT-IR (4000–400cm−1) and FT-Raman (3500–50cm−1) spectral measurements of solid sample of 2-
chloro-5-bromopyridine have been done. Ab initio and DFT calculations have been performed giving
energies, optimized structures, harmonic vibrational frequencies, depolarization ratios, IR intensities,
Raman activities and atomic displacements. Furthermore, force field calculations have been performed
by normal coordinate analysis. A complete assignment of the observed spectra, based on spectral correlations,
electronic structure calculations and normal coordinate analysis, has been proposed. The results
of the calculations have been used to simulate IR and Raman spectra for the molecule that showed good
agreement with the observed spectra. The SQM method, which implies multiple scaling of the DFT force
fields, has been shown superior to the uniform scaling approach. The energy and oscillator strength
calculated by Time-dependent DFT results are in good agreement with the experimental results.
Original languageEnglish
JournalSpectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Volume77
Issue number5
Pages (from-to)918-926
ISSN1386-1425
DOIs
Publication statusPublished - Dec 2010
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 114 Physical sciences

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