Premium
FTIR study of five complex β‐lactam molecules
Author(s) -
Gil Manuel,
Núñez José Luís,
Palafox Mauricio Alcolea,
Iza Nerea
Publication year - 2001
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1023
Subject(s) - chemistry , ring (chemistry) , lactam , amide , fourier transform infrared spectroscopy , molecule , planarity testing , nucleophile , stereochemistry , crystallography , organic chemistry , catalysis , physics , quantum mechanics
Five monocyclic 4‐benzoyl‐4‐phenyl‐β‐lactam derivatives in carbon tetrachloride solutions were studied by FTIR spectroscopy. The Fourier self‐deconvolution method was applied to enhance the resolution of the FTIR spectra. The calculated spectra of these five compounds, which were obtained by quantum mechanical methods, were compared with FTIR data. A complete assignment of the vibrational frequencies in the 4000–400 cm −1 range was made. Several vibrations were selected as being useful to characterize the β‐lactam ring. Substituents on N1 ( p ‐methoxyphenyl) and C3 (methyl, phenyl, maleimidyl, and phthalimidyl) on the β‐lactam ring increase the amide resonance and the planarity of the ring. The optimized geometry along with the total electric charges on the four atoms of the ring support an antibiotic action mechanism by a nucleophilic attack of the enzymes on the carbonyl carbon atom of the β‐lactam ring. © 2001 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 62: 278–294, 2001