Triplet-triplet absorption studies in acridine doped fluorene single crystals

Abstract Using time dependent phosphorescence and triplet-triplet absorption studies, the kinetics of the lowest excited triplet state of deuterated acridine has been studied up to room temperature in the hosts fluorene-d 8 h 2 , flourene-d 10 and dibenzofurane. A new high temperature decay channel is observed in the fluorene hosts with a large isotope effect with respect to the 9,9'CH 2 group of the host molecule. The relation to the photochemical hydrogen transfer reaction — found also in this system — will be discussed.