Abstract
FTIR spectra (50–4000 cm–1) were obtained in the temperature region 16–295 K for (E)2-hydroxyimino-2-cyanoacetic acid ethyl ester. A broadening of some peaks was observed while increasing the temperature. Broadening of the peak at 1187 cm–1 and its analysis vs. temperature enabled us to determine the barrier for CH2 twisting-rocking of 1.89±0.08 kJ/mole. The strong intensity dependence of the C=N stretching peak on temperature within the IR spectra is a sign of some nonlinear properties of the investigated substance. The splitting of several peaks connected with the C=N (azomethine), C=O and N-O vibrations provides evidence of two rotamers theoretically identified previously. The two rotamers existing distinctly (from the experimental point of view) at low temperatures differ one from the other only by 1 J/mol.
© by Oldenbourg Wissenschaftsverlag, München, Germany
