Polanyi rules for ultrafast unimolecular reactions: simulations for HCo(CO)4(1E)* .fwdarw. hydrogen atom + cobalt tetracarbonyl

Abstract

The traditional Polanyi rules for control of bimolecular reactions by selective investment of energy, e.g. preferentially translational, not vibrational energy for early-downhill reactions on attractive potential energy surfaces, are extended to ultrafast unimolecular reactions. Specifically, we consider photodissociations of the metal-hydrogen bond of HCo(CO) 4 ( 1 E), occurring on a time scale of approximately 20 fs, much faster than competing intramolecular vibrational energy redistribution (IVR). Here the reaction path toward the products H+Co(CO) 4 is hindered by a barrier located in the H+Co(CO) 4 exit valley of the potential energy surface