OXIDATION OF THE CYCLOHEXADIENYL RADICAL BY METAL-IONS - PULSE-RADIOLYSIS STUDY

The rates of oxidation of the cyclohexadienyl radical by metal ions in water have been measured. The bimolecular rate constants (dm3 mol-1 s-1) and corresponding reduction potentials (E0') were: Fe(C2O4)3-3: (1.30 ± 0.05) × 106 (0.002 V); Cu(H2O)2+6: (3.6 ± 0.6) × 106 (0.167 V); Fe(H2O)3+6: (2.5 ± 0.4) × 107 (0.77 V) and Ce4+ · nH2O: (1.5 ± 0.1) × 108 (1.70 V). Oxidation of the cyclohexadienyl radical by V(H2O)3+6 (-0.25 V) and Cr(H2O)3+6 (-0.40 V) ions was not observed (k < 105 dm3 mol-1 s-1) and it is suggested that the reduction potential of the cyclohexadienyl radical lies between -0.25 V and 0 V. © 1979.