Self-broadening coefficients and line strengths in the v₃ band of CH₃³⁵C1 at low temperature

Self-broadened linewidths have been measured in the P- and R-branches of the v band of CHCl at 200 K using a tunable diode-laser spectrometer. The lines under study are located in the spectral range 706-751 cm, with J values ranging from 3 to 27 and K from 3 to 6. The collisional half-widths were estimated along with the corresponding line strengths by fitting measured shapes of the individual lines with Voigt profiles convolved with the instrumental function. The line strengths at 200 K are in satisfactory agreement with results derived from previous measurements. Even though semi-classical calculations of line-broadening involving electrostatic interactions have yielded half-widths at 200 and 296 K that are greater than experimental data for low or medium values of J, they seem to predict correctly the K-dependence of the broadening coefficients of lines with the same J transition as well as their temperature dependence.