Anisotropic intermolecular potentials for HeC2H2, HeC2H4, and HeC2H6, and an effective spherical potential for HeCHF3 from multiproperty fits

Differential cross section (DCS) measurements are reported for scattering of a He atomic beam by crossed beams of C2H2, C2H4, C2H6, and CHF3. In addition, interaction virial measurements and accurate limiting diffusion measurements are presented for these systems. Damping of the DCS diffraction oscillations is used to extract anisotropic intermolecular potentials, which are constrained in multiproperty fits to accurately reproduce the dilute gas data. The radial anisotropies determined are in the sequence C2H6>C2H4∼C2H2>CHF3, as sampled by the He probe.