Self-Assembly and Fluorescence Properties of [60]Fullerene-Pentacene Monoadducts

The highly soluble [60]fullerene-pentacene monoadducts 2 a and 2 b were synthesized by a Diels-Alder reaction between [60]fullerene and pentacene derivatives. The single-crystal X-ray diffraction analysis of 2 a revealed an attractive intermolecular interaction between [60]fullerene moiety of one molecule and the pentacene arms of an adjacent molecule, resulting in the formation of head-to-tail dimers in solution. This self-association behavior of 2 a and 2 b was also observed by ¹H NMR and fluorescence spectroscopy in chloroform. Both the excitation and emission wavelengths can be modulated via the concentration of 2 a and 2 b.