Orange Room-Temperature Phosphorescence in Complexes of Pyrene-d10–β-Cyclodextrin with Bulk Molecules in the Presence of Oxygen

The long-lived room temperature phosphorescence (RTP) and fluorescence of a pyrene-d10–β-cyclodextrin (Pd10–CD) complex were studied before and after the removal of O2 as well as after the addition of bulk molecules (BM), namely, tert-butylbenzene, p-tert-butyltoluene, and adamantane. The biexponential decay of the RTP intensity of the complexes indicates the presence of two types of phosphorescent sites (PSs) in the crystal lattice of 2BM-2CD. The emission and quenching rate constants of Pd10 RTP in all the complexes and the PS structures were calculated by quantum chemistry methods. The assignments and selection rules of vibrational fine structure lines in the emission spectra are discussed.