Extensive experiments on the K=5 component of the J=14–13 rotational transition of CH 3 35 Cl, located near 372GHz, were performed at different temperatures in the range 235–350K. They allow the determination of the N 2 - and O 2 -broadening coefficients, and their temperature dependences. More specific measurements on a great number of K-components of the involved transition perturbed by N 2 at 301K allow to point out a clear decreasing of the broadening coefficients with increasing K. All the experimental parameters are compared with results derived from a semiclassical calculation of collisional interactions, including electrostatic, induction, and dispersion energy contributions.