The host compounds tetrakis-(4-bromophenyl) ethylene and its iodo-analogue form inclusion compounds with a series of chloro- and iodo-methanes. Their structures have been elucidated and their non-bonded halogen∙∙∙halogen contacts analysed and classified. Their kinetics of desolvation have been studied and the concomitant activation energies established. Five of then clathrates are isostructural and display similar activation energies of desolvation, thus correlating structure and function. The velocity of the enclathration for the solid host-methyl iodide vapour reactions and associated rate law have been established.