OVERTONE SPECTRUM OF THE CH CHROMOPHORE IN CHI3

摘要

The infrared spectrum of iodoform vapor was measured between 900 and 10 000 cm(-1) in a heatable multipass cell with an interferometric Fourier transform spectrometer and temperatures up to 433 K. Twenty-five bands (including hot bands) could be assigned as fundamentals, overtone, or combination bands of the CH stretching and bending vibrations. The observed data are interpreted in terms of variational calculations using internal and normal coordinates and some evidence is given for the existence of a strong coupling constant k(sbb)' = 50 cm(-1) between the two vibrational modes with subpicosecond redistribution of energy. Off-diagonal anharmonic constants between the CH stretching and bending manifold and the molecular frame vibrations have been determined. (C) 1995 American Institute of Physics. [References: 61]