CASSCF study into the mechanicism for predissociation of the allyl radical

摘要

A theoretical study has been carried out on the allyl radical in its ground and first excited electronic states. Complete active space self-consistent field (CASSCF) calculations show the presence of a conical intersection between the ground and first excited electronic states (similar to 400 cm(-1) above the adiabatic excited state energy), reached by decreasing the C-C-C angle and twisting the C-C bonds. The presence of this conical intersection provides a likely explanation for the very rapid predissociation in the excited electronic state. (C) 2005 Wiley Periodicals, Inc.