Complexation is the process where by two species join together to form a single species. The joining process may proceed via LUMO/HOMO Lewis acid/Lewis base, SOMO/SOMO radical/radical or steric Guest/Host types of interaction. Complexation processes are bimolecular in the formation direction and unimolecular in the decomplexation direction. For more information look in the Chemogenesis
webbook sections on complexation,
acid/base interaction matrix.