Novel sugar-bridged fullerene dumbbells and their interaction with the [10]cycloparaphenylene nanoring.

Abstract

We describe the synthesis and characterization of four dumbbell-shaped fullerene molecules bridged by isosorbide \ isomannide moieties. Their electrochemical behaviour and complexation with [10]cycloparaphenylene ([10]CPP) were also investigated. Cyclic voltammetry (CV) of fullerene dumbbells showed high electron affinity, highlighting their ability to interact well with electron-donating counterparts such as carbon nanorings, which are charge and shape complementary. Thermodynamic and kinetic parameters of complexation were studied by isothermal titration calorimetry (ITC) and additional information about binding stoichiometries was obtained by NMR titration experiments. Two different approaches were used, resulting in bridged cyclopropane- and furan-based structures. Regardless of the type of linker, all derivatives formed conventional 2:1 complexes [10]CPP2⊃C60 derivative. However, the methano-dumbbell molecules showed different binding behaviour as mono-, bis-pseudorotaxanes as well as oligomers (polymers) were detected. The formation of linear polymers could be of great importance for solar energy conversion processes.