Synthesis of C60-diphenylaminofluorene dyad with large 2PA cross-sections and efficient intramolecular two-photon energy transfer.

The first, highly two-photon active C60 derivative comprised of a A-sp3-D conjugate structure was synthesized showing effective two-photon absorption cross-sections (sigma 2' = 196 x 10(-48) cm4 sec-1 molecule-1) in the nanosecond regime among the best values for diphenylaminofluorene-based AFX chromophores.