Continuous wave (CW) and time-resolved (TR) EPR spectra of triplet C60 with partial and full 13C enrichment in methylcyclohexane solutions after UV irradiation were obtained. Line broadening from 13C satellites was observed. The 13C hyperfine coupling constant was determined to be 0.06 G. Fourier transform EPR (FT-EPR) experiments with a resolution of 20 ns were carried out, and T1 was found to be 0.8 ± 0.1 μs by fitting the intensity of the free induction decay signal to the modified Bloch equations. The relaxation time from FT-EPR is in excellent agreement with estimations from the line width of CW-EPR. Because the 13C hyperfine coupling constant is so small, no distinct satellite lines were observed with 13C in natural abundance at 200 K.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry