The foreign-gas broadening parameter for fluoroform molecules interacting with nonpolar BCl3 molecule as perturber has been measured and the collision cross section has been determined. The results are pressure broadening coefficient Cw = (43 ± 1) [kHz/Pa] for J = 1 ← 0 rotational transition of CHF3 molecule in mixture with BCl3 gas, and collision cross section σexp = 294.0 [Å2]. Experimental linewidth parameter is interpreted using Anderson–Tsao–Curnutte as well as Murphy–Boggs theories for the mixed- interaction case. From this analysis a value of molecular quadrupole moment Q = (4.1 ± 0.2) [DÅ2] of boron trichloride molecule has been obtained.

Self-broadened width of J = 6 7 rotational line in the ground state of t-butyl cyanide molecule has been measured at room temperature. The measurements of the linewidth as a function of the gas pressure were carried out with home-made spectrometer at the frequency ν0 = 38 498.308 MHz. The mean value of the pressure-broadening coefficient c = 76.9 ± 0.6 MHz Τorr -1 was obtained.

The collision cross section of rotational transition J=0→1 in the CHF3 molecule caused by nonpolar perturbers has been measured. The observed cross sections depend linearly on (mQ22)1/3, where Q2 is the quadrupole moment of the perturber and m is the reduced mass of the colliding molecules. Calculations based on the Murphy-Boggs theory using the dipole-quadrupole and first order dispersion interactions for a description of CHF3+C2H2, C6H6, CO2, O2 collisions are in qualitative agreement with the experimental results. The theoretical values are in general lower than the experimental values, and especially in the case of O2 collisions, the first order dispersion interaction contributes largely to the collision cross section.