Coupling a dendrimer and a fullerene chromophore: a study of excited stateproperties of C-61(poly(aryl)acetylene)(2)

A new methanofullerene, C-61(poly(aryl)acetylene)(2), where the mono-adduct contains dendrimer units, has been studied with respect to its photophysic al properties. The visible absorption and the emission spectra, the triplet molar extinction coefficient as well as the near unity value of the quantu m yield of singlet oxygen production upon photoexcitation reveal characteri stics in keeping with other methanofullerenes previously studied, where the addend species is not an electron donating group. The results indicate tha t, even when the methanofullerene is photoexcited, this large addend does n ot electronically communicate through the methane bridge neither through sp ace. Photophysical properties of methanofullerenes can thus be preserved wh en they are functionalised with such addends. (C) 2001 Elsevier Science B.V . Ah rights reserved.