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Structural, vibrational spectra and normal coordinate analysis for two tautomers of 4(5)‐(2′‐furyl)‐imidazole
Author(s) -
Ledesma A. E.,
Zinczuk J.,
López González J. J.,
Ben Altabef A.,
Brandán S. A.
Publication year - 2010
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.2482
Subject(s) - tautomer , natural bond orbital , chemistry , imidazole , delocalized electron , raman spectroscopy , density functional theory , computational chemistry , infrared spectroscopy , nuclear magnetic resonance , stereochemistry , organic chemistry , physics , quantum mechanics
Abstract We have synthesized both the 4 and 5 tautomeric forms of 4(5)‐(2′‐furyl)‐imidazole (1) and investigated their molecular vibrations by infrared and Raman spectroscopies as well as by calculation based on the density functional theory (DFT) approach. Examination of the temperature dependence of IR intensity revealed the band characteristics of the 4 and 5 tautomers of (1). Comparison of experimental and calculated chemical shifts in nuclear magnetic resonance (NMR) spectroscopy was made in order to identify the two tautomeric forms. The assignment of vibrational normal modes was performed, and the force field obtained reproduced the experimental vibrational wavenumbers with a root mean‐square deviation (RMSD) value of ca . 13 cm −1 for both tautomers. The natural bond orbital (NBO) study reveals the characteristics of the electronic delocalization of the two tautomeric structures. Copyright © 2009 John Wiley & Sons, Ltd.