Reducing-difference infrared spectral analysis of cis- and trans-configurated lactams.
The conventional (non-polarized) and linear-polarized IR-spectra of 2-pyrrolidone and laurolactam as typical representatives of lactams with cis- and trans-amide configuration, respectively, were studied by means of difference IR-spectroscopy. The application of this method to treatment of the non-polarized IR-spectra permits additional conclusions about the likely self-associates of these compounds dissolved in aprotic solvents. By means of the difference linear-dichroic IR-spectroscopy, a more precise assignment of the characteristic bands of the lactam cis- and trans-peptide forms as well as their stereo structures were accomplished. A comparative analysis with the linear-dichroic IR-spectra of epsilon-caprolactam and caprylolactam, as similar compounds, with cis- and trans-conformation, respectively, was also carried out.
University of Sofia, Department of Chemistry, 1, J. Bourchier blvd., 1164 Sofia, Bulgaria. marnaudov@chem.uni-sofia.bg
M G
MG
Arnaudov
B B
BB
Ivanova
St T
ST
Todorov
S Io
SI
Zareva
D007536:Isomerism; D007769:Lactams / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
D007769:Lactams; C474694:laurolactam