Radical pairs, electron spin resonance relaxation times, and limiting radical concentrations in .gamma.-irradiated 3-methylpentane glass

Abstract

References and Notes(1) Photochemical reactions of coordination compounds are reviewed in V.Balzanl and V. Carassiti, "Photochemistry of Coordination Compounds," Academic Press, New York, N.Y., 1970.(2) Emission characteristics of inorganic complexes are reviewed in P. D.Fleischauer and PI. Fleischauer, Chem. Rev., 70, 199 (1970). ( 3) Procedures for measuring emission quantum yields are reviewed in J. N.Demas and G. A. Crosby, J. Phys. Chem., 75, 991 (1971).(4) Luminescence efficiency measurements for powders are reviewed in F.

Effects of solutes, deuteration, and annealing on the production and decay of radicals in .gamma.-irradiated 3-methylpentane glasses

“…Radical pairs have been detected in 7-irradiated 3MP glass at 77°K, but is not yet known whether these result from a mechanism of pair production during irradiation, or only from pair production by diffusive encounters. 3 The improvement in resolution• of the ESR spectra of the radicals produced by 7 irradiation of 3MP glass as decay progresses (Figure 3C) is presumed to be due to a decrease in line broadening by electron dipole interactions between closely spaced radicals, as these radicals are removed by intraspur decay. Consistent with this interpretation, the resolution of the spectra of CgHis radicals formed randomly in 3MP glass by the hot radicals formed in the photolysis of CH3I (CH3* + CgHi4 -* CgHis + CH4) is equivalent to that after prolonged decay in 7-irradiated samples.…”