Long Lived Delayed Fluorescence of Ternary Naphthalene-beta-Cyclodextrin-Cyclohexane Complexes at Room Temperature

Long-lived delayed fluorescence of dispersions of microcrystals of naphthalene-beta-cyclodextrin-cyclohexane ternary complexes has been studied. It has been established that the delayed fluorescence is due to the T-T annihilation process. The kinetics of delayed fluorescence has a nonexponential character; the average lifetime is 0.68 s. The shape of the decay rate curves of delayed fluorescence does not depend on the intensity of excitation light. The nonexponential nature of the delayed fluorescence is presumably associated with the presence in the crystals of paired naphthalene molecules with different mutual positions and pair formation energies.