1Department of Chemical Engineering & Chemistry, Iran University of Science and Technology, Tehran, I.R. IRAN
2Department of Chemistry, University of Massachusette Dartmouth, North Dartmouth, MA 02747, U.S.A
A classical theory is developed which calculates the momentum transfer rate constant between an ion and a non-polar molecule. The model takes into consideration the effect of diffraction outside the capture limit on the rate constants. The theory is used to calculate momentum transfer rate constant for Cl- with trans-dichloroethylene and para-difluorobenzene. Theoretical results are compared to those predicted by the Langevin model and also with the experimental data. It is shown that the inclusion of diffraction outside the capture limit increases the theoretical momentum transfer rate constants. It is suggested that other potential terms may be important in determining momentum transfer rate constants for these systems.