A nanohybrid combining two allotropic forms of carbon, namely carbon nanohorns (CNH) and C60, has been obtained from a C60 derivative bearing a benzocrown ether subunit (crown–C60) and a CNH functionalized with NH3+ groups (CNH-sp-NH3+F−) through ammonium–crown ether interactions. The resulting CNH–C60 nanohybrid has been characterized by Raman and XPS spectroscopies, thermogravimetric analysis (TGA) and high-resolution transmission electron microscopy (HR-TEM). The photophysical properties of the CNH–C60 conjugate have been investigated in benzonitrile. Femtosecond laser flash photolysis measurements revealed the occurrence of an efficient electron transfer from the singlet excited state of the C60 moiety to the CNH with a rate constant of 6.5 × 1010 s−1 to produce a radical ion pair, which decayed by charge recombination with a lifetime of 1.0 ns to afford the triplet excited state of CNH-sp-NH3+F− and crown–C60. The two carbon nanoforms play therefore complementary roles in the CNH–C60 conjugate, the CNH acting as an electron donor and C60 as an electron acceptor.

The research at Osaka University was supported by Grant-in-Aid (no. 20108010 to SF and no. 23750014 to KO) and Global COE program, “the Global education and Research Centre for Bio-Environmental Chemistry” from the Ministry of Education, Culture, Sports, Science and Technology, Japan and by WCU (R31-2008-000-10010-0) and GRL (2010-00353) programs of KOSEF/MEST, Korea. The research at University of Castilla-La Mancha was supported by the Ministry of Economy and Competitiveness of Spain (projects CTQ2010–17498/BQU and PLE-2009-0038).

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