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. Highly soluble [60]fullerene‐pentacene monoadducts were obtained from a Diels‐Alder reaction between [60]fullerene and pentacene derivatives. These highly soluble [60]fullerene‐pentacene monoadducts behave as molecular switches and exhibit concentration‐dependent switching of dual excitation and dual emission.