Electrosynthesis and structural characterization of two (C₆H₅CH₂)₄C₆₀ isomers

The structural, spectral, and electrochemical properties of two (C₆H₅CH₂)₄C₆₀ isomers are reported. One is designated as the 1,4; 1,4- (C₆H₅CH₂)₄C₆₀ isomer and the other as the 1,4; 1,2-isomer of (C₆H₅CH₂)₄C₆₀. The two isomers were isolated by HPLC from the products obtained by a reaction between [(C₆H₅CH₂)₂C₆₀]^2- and C₆H₅CH₂Br. X- ray data show that the two (C₆H₅CH₂)₄C₆₀ isomers differ from one another by the position of only one benzyl group and that, in each compound, the four benzyl addends are in close proximity. Both (C₆H₅CH₂)₄C₆₀ isomers undergo three one-electron reductions in PhCN containing 0.1 M tetra- n-butylammonium perchlorate (TBAP) and have E( 1/2 ) values which are more negative than values for either C₆₀ or 1,4-(C₆H₅CH₂)₂C₆₀. The monoanions of 1,4;1,4- and 1,4;1,2-(C₆H₅CH₂)₄C₆₀ were electrogenerated by bulk controlled-potential electrolysis in PhCN containing 0.2 M TBAP and characterized as to their spectral properties in both the visible and near- infrared regions.