Synthesis and redox properties of TCNQ and DCNQI-type electron-acceptor methanofullerenes

The first TCNQ- and DCNQI-type spiromethanofullerenes (4 and 5) have been prepared from the quinone-type spiromethanofullerene 3 by reaction with the Lehnert reagent (malonitrile, titanium tetrachloride and pyridine) and bis(trimethylsilyl)carbodiimide (BTC) and titanium tetrachloride, respectively. The cyclic voltammetry reveals that these novel compounds are better acceptors than the starting quinone-type spiromethanofullerene and comparable to the parent [60]fullerene.