Photoinduced charge transfer interaction between fullerene[60] and diphenylpolyenes in solution: evidence for photocycloaddition reaction

Abstract

The charge transfer interaction between C 60 and diphenylpolyenes, namely 1,4-diphenylbutadiene and 1,6-diphenylhexatriene, has been studied in benzene and benzonitrile solutions using transient absorption techniques with pico to microsecond time resolution. Polyenes form weak ground state charge transfer complexes with C 60 in benzonitrile, but not in benzene. In benzonitrile the charge transfer complex undergoes charge separation on photoexcitation to form a contact ion-pair, which undergoes a fast charge recombination process. Diphenylpolyenes also interact with the excited triplet state of C 60. The interaction of the polyenes with the excited states of C 60 gives rise to a cycloaddition product.