Evidence of charge transfer between C60 and interstitial NO or O2 in solid C60

Solid C60 was stored in NO or O2 under high pressure, and subsequently the molecules of either gas were found to have diffused into the octahedral interstitial sites in its fcc lattice. 13C NMR MAS spectroscopy revealed a primary resonance at 143.7 ppm, accompanied by several minor peaks shifted downfield. Measurement at temperatures from 210 to 300 K indicated a linear dependence of the chemical shifts of these minor peaks on inverse temperature,with intercepts equal to integral multiples of 0.13 ppm. In view of these finite intercepts at the high-temperature limit, we propose that there are charge transfers to C60 from NO and from O2. The quantities of the charge transferred have been calculated, and in both cases are about 0.065 electron charge.