The 3, 6-bis (trimethylsilyl) cyclohexadienyl radical (1), generated from the corresponding cyclohexadiene, gave the expected p-bis (trimethylsilyl) benzene (4) at 0° C. At 130° C, however, the reaction afforded trimethylsilylbenzene, 4, and m-bis (trimethylsilyl) benzene in 62, 17, and 5% yield, respectively. The suggested elimination of the trimethylsilyl radical from the cyclohexadienyl radical is demonstrated by ESR.