Intersystem crossing in several long-lived trans-stilbene singlet exciplexes is found to occur via oxygen-independent and oxygen-catalyzed pathways. Rate constants for oxygen-independent intersystem crossing are in the range 1-5 × 107 s-1. Intersystem crossing results in efficient population of the triplet state of trans-stilbene and inefficient population of the other exciplex partner. This result is in accord with Boltzmann controlled population of the two triplet species. The population of triplet species via recombination of solvated radical ions is highly inefficient even though population of triplet stilbene should be exothermic.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry