Electrosynthesis and Structural Characterization of Two (C6H5CH2)4C60 Isomers

The structural, spectral, and electrochemical properties of two (C 6 H 5 CH 2 ) 4 C 60 isomers are reported. One is designated as the 1,4;1,4-(C 6 H 5 CH 2 ) 4 C 60 isomer and the other as the 1,4;1,2-isomer of (C 6 H 5 CH 2 ) 4 C 60 . The two isomers were isolated by HPLC from the products obtained by a reaction between [(C 6 H 5 CH 2 ) 2 C 60 ] 2 - and C 6 H 5 CH 2 Br. X-ray data show that the two (C 6 H 5 CH 2 ) 4 C 60 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 (C 6 H 5 CH 2 ) 4 C 60 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 C 60 or 1,4-(C 6 H 5 CH 2 ) 2 C 60 . The monoanions of 1,4;1,4- and 1,4;1,2-(C 6 H 5 CH 2 ) 4 C 60 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.