Theoretical studies of force fields and IR spectra of isocytosine

✍ Scribed by Guosen Yan; Ying Xue; Daiqian Xie

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 355 KB
• Volume: 72
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(1999)72:1<53::aid-qua5>3.0.co;2-w

✦ Synopsis

The optimized geometries, complete harmonic force fields, and infrared

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intensities of isocytosine tautomers, amino-hydroxy and amino-oxoN 1 H, were calculated at the ab initio Hartree᎐Fock level using the 6-31G* basis set. The theoretical force fields were scaled by empirical scale factors, which were determined by fitting to the IR spectrum of the amino-oxo form and were then transferred to the amino-hydroxy form. The average deviations between experimental and computed frequencies are 7.6 cm y1 for amino-oxo and 9.5 cm y1 for amino-hydroxy, respectively. The assignments of the fundamental frequencies and the transferability of the force constant scale factors are also presented.