Collision Cross Section of the J = 2 <- 1 Rotational Transition of CF3CCH due to Higher Order Interactions

TL;DR

This study measures the collision cross section of CF3CCH's rotational transition due to rare gas interactions and compares experimental results with theoretical predictions, highlighting the role of higher order interactions.

Contribution

It provides new experimental data on pressure broadening and shift parameters for CF3CCH with various rare gases, and compares these with theoretical models including higher order interactions.

Findings

Pressure broadening parameters for CF3CCH with rare gases were determined.

Pressure shift parameter for CF3CCH was measured.

Theoretical calculations qualitatively agree with experimental data.

Abstract

The collision cross section of the rotational transition J = 2 <- 1 of 3,3,3-trifluoropropyne, CF3CCH, caused by rare gas perturbers has been determined by investigating transient emission signals of molecular gas samples. From analysis of the pressure dependence of the width of the rotational line J = 2<-1 pressure broadening parameters have been derived for the pure gas and for mixtures with the rare gases He, Ne, Ar, Kr and Xe. The pressure shift parameter for the pure gas sigmas/p = 29.03(12) kHz/Pa also has been obtained. Calculations based on the Anderson-Tsao-Curnutte theory using induction and dispersion interactions for the description of collisions of CF3CCH with He, Ne, Ar, Kr and Xe, respectively, are in qualitative agreement with the experimental results.