Infrared band contours and potential functions for the perpendicular vibrations of CF3Cl, CF3Br, and CF3I

The infrared band contours of the perpendicular vibrations of CF3Cl, CF3Br, and CF3I were measured in the infrared spectra, and the Coriolis constants for these vibrations were evaluated by a computer-simulation procedure that calculates the band shape as a function of the molecular parameters. The Coriolis constant for the ν5 band of CF3Br was evaluated by an analysis of the partially resolved Q branches in the high-resolution spectrum. With the vibrational frequencies and Coriolis constants as input data, the E -species force constants of the general harmonic potential function were evaluated. Two different force fields were found for each molecule that exactly fit the experimental data.