THE TRIPLET EXCITED-STATE OF NAPHTHALENE IN MIXED-SOLVENTS - A PULSE RADIOLYTIC STUDY

Using 2-mu-s, 7 MeV electron pulses, the triplet excited state of naphthalene (N-3*) has been produced from solutions of naphthalene in cyclohexane-isopropanol and cyclohexane-t-butanol mixtures. Its yield and decay kinetics have been studied over a range of compositions (100% cyclohexane to 100% alcohol). The yields of the N-3* decreased with increasing alcohol concentration. The decay followed mixed order kinetics throughout. Second order decay constants calculated by resolving the decay into first and second order components varied with composition in a manner which was not matched by variations in either viscosity or dielectric constant. However, the fact that the triplet decay is closely related to the microstructure of the solvent is shown by the inverse relationship between the second order rate constant and the spin lattice relaxation time for t-butanol.