Structural Evidence for the Expected Jahn-Teller Distortion in Monoanionic C60: Synthesis and X-ray Crystal Structure of Decamethylnickelocenium Buckminsterfulleride

Abstract

We have approached the synthesis of discrete fulleride salts, through the use of strongly reducing organometallic species such as metallocenes, which allow precise control of stoichiometry for the production of C{sub 60}{sup n-} species. Decamethylnickelocene Ni(C{sub 5}Me{sub 5}){sub 2}, is a selective reductant for the production of C{sub 60} monoanion and yields a crystalline 1:1 salt when combined with C{sub 60} in CS{sub 2}. The structure of this salt [Ni(C{sub 5}Me{sub 5}) {sub 2}{sup +}][C{sub 60}{sup -}].CS{sub 2} (1), is highly ordered and is the first example of a non-disordered monoanionic C{sub 60} structure. We report here the synthesis and single-crystal X-ray structure of 1 and structural evidence for the expected Jahn-Teller distortion in the C{sub 60} monoanion. 16 refs., 3 figs.