COMPARATIVE ESR STUDY OF C-60 AND C-70 RADICAL ANIONS PRODUCED IN GAMMA-IRRADIATED ORGANIC SOLID SOLUTIONS AT 77 K

摘要

ESR spectra of C-70 radical anions were detected for C-70/methylcyclohexane (MCHX) and C-70/2-methyltetrahydrofuran (MTHF) solid solutions which were gamma-irradiated at 77 K and subsequently annealed at 107-117 K. The ESR spectrum for C-70/MCHX was a singlet which was ascribed to C-70(-), and was flanked by a pair of satellites due to matrix proton spin flip lines. The ESR spectrum for C-70/MTHF was a superposition of a singlet and a deformed doublet. The latter was unstable and disappeared at 109 K, and was tentatively ascribed to C-70(2-). ESR spectra of C-60 radical anions were partly reinvestigated and are compared to those of C-70. The relative electron attachment efficiencies for C-60 and C-70 at 77 K were estimated, and the former was about twice as large as the latter. Isothermal decay at 77 K was observed for both C-60 and C-70 radical anions. [References: 23]