Decatungstate‐Photocatalyzed Radical Addition of 9‐Substituted Fluorenes to [60]Fullerene: A Mechanistic Approach

Abstract An innovative, efficient, regioselective functionalization of C 60 with 9H ‐fluorenes has been disclosed. This efficient photochemical approach uses certain fluorenyl radicals in 9 ‐ position deriving from fluorenes through a hydrogen‐atom transfer (HAT) process mediated by tetrabutylammoniumdecatungstate [( n ‐Bu 4 N) 4 W 10 O 32 ]. The single addition of these fluorenyl radicals to C 60 proceeded to produce [60]fullerene‐fluorene dyads in a single step. The scope and mechanism of this new reaction have been examined. The primary kinetic isotope effect measurements signify the presence of a stepwise mechanism in which the C−H (D) bond scission is the rate‐limiting step of the reaction.