Environmental effects on electron spin relaxation in N@C60

We examine environmental effects of surrounding nuclear spins on the electron spin relaxation of the N@C-60 molecule (which consists of a nitrogen atom at the center of a fullerene cage). Using dilute solutions of N@C-60 in regular and deuterated toluene, we observe and model the effect of translational diffusion of nuclear spins of the solvent molecules on the N@C-60 electron spin relaxation times. We also study spin relaxation in frozen solutions of N@C-60 in CS2, to which small quantities of a glassing agent, S2Cl2, are added. At low temperatures, spin relaxation is caused by spectral diffusion of surrounding nuclear Cl-35,Cl-37 spins in the S2Cl2, but, nevertheless, at 20 K, T-2 as long as 0.23 ms is observed.