PHASE-SHIFT OF QUANTUM OSCILLATIONS IN THE RECOMBINATION LUMINESCENCEOF SPIN-CORRELATED RADICAL-ION PAIRS

The phase shift of quantum oscillations observed in the recombination fluorescence of the (diphenylsulfide-d(10))(+)/ (p-terphenyl-d(14))(-) radical ion pair in isooctane has been detected experimentally. The s hift is caused by the delay in (diphenylsulfide-d(10))(+) formation in the reaction of solvent holes with a diphenylsulfide molecule. Compar ison with a theoretical model has given for the rate constant of isooc tane hole capture by diphenylsulfide molecules the value (3.5 +/- 1) x 10(10) M(-1) s(-1) which exceeds the diffusion-controlled one. The fr action of singlet-correlated pairs in the track has been estimated fro m the oscillation amplitude to be approximately 35%.