Triplet excimer formation and phosphorescence in fluid solutions of diarylalkanes: Excimer phosphorescence of dinaphthylalkanes and monomer phosphorescence of diphenylpropane

The excimer phosphorescence, delayed fluorescence, and triplet–triplet absorption of α,α-dinaphthylalkanes have been investigated in isooctane at several temperatures. The results are consistent with the formation of intramolecular triplet excimers whose conformation is significantly different from that favored by singlet excimers. 1,3-diphenylpropane displays only monomerlike phosphorescence in fluid media over a wide temperature range, indicating that the binding energy of this triplet excimer is considerably smaller than that for the triplet excimers of dinaphthylalkanes.