Fullerene acceptor strength

The low oxidation state of Pd(0) and the high rr-backbonding acceptor nature of fullerenes contribute to reinforce the Pd-fullerene bond strength. This facilitates the syntheses of these complexes, which can be easily prepared from C60 (or G70) and Pd(0) precursors, such as PdL4, Pd2(dba)3, or by ligand exchange from C6oPdL2 (Scheme 43).2 ... 

Cyclic voltammetry measurements elucidated that in this kind of molecule the carborane behaves as a donor because of its smaller acceptor strength compared with the fullerene. 

Regarding fullerene chemistry, whereas the covalent functionalisation of buckminsterfiillerene Ceo has seen dramatic development, the supramolecular aspects of its chemistry have not been explored to the same extent. In contrast to covalent bonds, the formation of H-bonds is reversible and their strength depends on the chemical environment, such as the solvent or temperature. This important difference has been skillfully used in the preparation of a variety of reversible donor-acceptor dyads. 

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