Synthesis, X-ray structure, and properties of the singly bonded C60 dimer having diethoxyphosphorylmethyl groups utilizing the chemistry of C60(2-).

[reaction: see text] A singly bonded C60 dimer having a diethoxyphosphorylmethyl group on each C60 cage was obtained by the reaction of C60(2-) dianion with diethyl iodomethylphosphonate followed by the treatment with iodine. The precise structure of the dimer was determined for the first time by X-ray crystallography, and its homolytic dissociation as well as spectroscopic and electrochemical properties were clarified.