ORIENTATIONAL BEHAVIOR OF C-70 MOLECULES IN CHLOROBENZENE

The orientational behavior of C-70 singlet excited molecules in a chlo robenzene solution has been measured at room temperature by the picose cond transient grating technique. A two-stage decay signal was observe d: a fast part (tau = 12 +/- 5 ps) which is comparable with the corres ponding signal of C-60 in chlorobenzene (tau = 8 +/- 2 ps), and a slow part (tau = 30 +/- 5 ps). The data obtained are analyzed in terms of the rotation of C-70 molecules. The influence of the dielectric fricti on on the C-70 rotation is reported.