CHARGE SEPARATION IN TRIPLET C-60 TMPD EXCIPLEXES

A transient de photoconductivity technique was used to demonstrate the formation of dipolar exciplexes of the triplet C-60 State with N,N,N' ,N'-tetramethyl-1,4-phenylenediamine (TMPD) in toluene. The dipole mom ent of the C-3(60)/TMPD exciplex was measured to be 35 +/- 4 D. Unit c harges separated by 7.1 Angstrom, the center-to-center distance estima ted for C-60 in van der Waals contact with TMPD, correspond to a dipol e moment of 34 D. This implies that the triplet exciplex has essential ly complete charge transfer. The lifetime of the exciplex was determin ed to be 7 +/- 2 ns.