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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2006-1-27
pubmed:abstractText
The molecular vibrations of 2-mercapto pyrimidine (MP) and 2,4-diamino-6-hydroxy-5-nitroso pyrimidine (DAHNP) were investigated in polycrystalline sample, at room temperature, by Fourier transform infrared (FT-IR) and FT-Raman spectroscopics. In parallel, ab initio and various density functional (DFT) methods were used to determine the geometrical, energetic and vibrational characteristics of MP and DAHNP. On the basis of B3LYP/6-31G* and B3LYP/6-311+G** methods and basis set combinations, a normal mode analysis was performed to assign the various fundamental frequencies according to the total energy distribution (TED). Simulation of infrared and Raman spectra, utilizing the results of these calculations led to excellent overall agreement with observed spectral patterns. The scaled quantum mechanical (SQM) approach applying selective scaling of the DFT force fields was shown to be superior to the scaling method in its ability to ensure correct band assignments and successful simulation of IR and Raman spectra including band polarisations and intensity patterns.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1386-1425
pubmed:author
pubmed:issnType
Print
pubmed:volume
63
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
454-63
pubmed:dateRevised
2007-7-4
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Molecular and vibrational structure of 2-mercapto pyrimidine and 2,4-diamino-6-hydroxy-5-nitroso pyrimidine: FT-IR, FT-Raman and quantum chemical calculations.
pubmed:affiliation
Department of Physics, Periyar University, Salem 636 011, India. vkrishna_kumar@yahoo.com
pubmed:publicationType
Journal Article