Prompt and delayed dissociation of energy-rich larger molecules

Coexistence of prompt and delayed decay modes of energized polyatomic molec ules is discussed with reference to the special features of larger molecule s which makes it amenable to experimental observation by a suitable choice of initial conditions. The molecular parameters identified by the RRKM theo ry of unimolecular (delayed) decay suffice to characterize the prompt proce ss as well. The expected "kinetic stability" of large molecules is thus not necessarily the rule, and fast processes are possible, suggesting the poss ibility of experimental control.