Abstract
Azafullerene C59N, i.e., one carbon atom of the C60 cage replaced by a nitrogen atom, has attracted attention because of its superior electron affinity and unique reactivity. In order to establish the efficient way to functionalize C59N core, we first studied the reaction of the dimer (C59N)2 with some pyrrole derivatives under the presence of oxidizing reagents such as 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), iodine, and p-chloranil. As a result, the electrophilic substitution reaction of 2-acetylpyrrole was found to proceed smoothly at 70 ˚C in 1,2-dichlorobenzene when DDQ was employed. Then, we extended the scope of this reaction to a typical pyrrole-containing fluorescent dye, BODIPY, and actually obtained the desired dyad in which a BODIPY unit was directly connected to the C59N core via a C-C single bond. The transient absorption spectra and fluorescent lifetime measurements revealed that ultrafast intramolecular photoinduced energy transfer from the BODIPY unit to the C59N core occurred on the femtosecond time scale.
