The comparisons of fluorescence quenching between perylene and pyrene

The fluorescence quenching of perylene and pyrene by dimethyl terephthalate (DMTP) and N, N-dimethylaniline (DMA) have been investigated. The results show that pyrene can form exciplex with DMTP or DMA at room temperature and perylene can only form exciplex with DMA. The fluoescence quenching date is in conformity with the Stern-Volmer equation: F-0/F = 1 + K-SV [Q] = 1 + K-q.tau (0) [Q], the F-0/F-[Q] straight lines are drawn. The Stern-Volmer constants and fluorescence quenching rate constants (K-SV and K-q) are obtained. The Stern-Volmer quenching constants of pyrene is larger than that of perylene. The differences is due to the molecular structure of perylene which is not a typical large conjugated system and less coplanar configuration than pyrene.