ESR spectral studies of chemically and electrochemically generated C/sub 60//sup n-/ and R//sub n/C/sub 60//sup n-/ anions

Summary form only given. ESR spectra have previously been obtained for C/sub 60//sup n-/ anions, where n = 1, 2, or 3, and confirm that the LUMO of C/sub 60/ is triply degenerate. As part of our efforts to generate new C/sub 60/ derivatives,/sup 2/ we have now examined the ESR spectra of chemically and electrochemically generated (CH/sub 3/)/sub 2/C/sub 60//sup n-/ anions, where n = I or 2, with special emphasis on the temperature dependence of the g values and the ESR linewidths. Both the mono- and dianions of (CH/sub 3/)/sub 2/C/sub 60/ give narrow ESR lines (/spl Delta/H /spl tilde/ 2 G) and are centered around g = 2.002, typical of organic free radicals. The g values and the ESR linewidths were analyzed as a function of temperature and solvent, and the data compared to that obtained from similar studies on C/sub 60//sup n-/ and C/sub 60/H/sub 2//sup n-/ anions, /sup 1,3/ where n = I or 2. Changes in the LUMO configuration of C/sub 60/ upon derivatization will be discussed.