[RuIII(NH3)5pzCH3]4+錯合物氧化維他命C及一系列catechols之反應，屬外圈電子轉移機構，在[H+] = 0.01 – 0.1M，μ = 1 M HClO4 / LiClO4 , T=25℃條件下進行動力學探討，結果分別得k0 = (4.9±0.3) × 102 (Ascorbic acid)，(5.88± 0.04) × 102 (Pyrocatechol)，(6.31± 0.03) × 102 (catechin) ; k1 = (2.78± 0.01) × 107 (ascorbic acid)，(1.32± 0.04)× 1010 (Pyrocatechol)，(1.01± 0.01) × 107 (4-nitrocatechol)，(4.68± 0.04) × 109 (catechin) 。動力學結果顯示hydroquinones與ascorbic acid反應機構相似，修正反應能障kcorr = 後，我們發現catechols反應活性比ascorbic acid大了ㄧ次冪，因此catechols的抗氧化力比ascorbic acid好。Marcus 理論修正，進一步發現catechols kex應較ascorbic acid大2次冪以上。 The oxidation of ascorbic acid and a series of catechols (hydroquinones) by [RuIII(NH3)5pzCH3]4+ complexes undergoes an outer-sphere electron transfer mechanism. The kinetic studies of the reaction at [H+] = 0.01 – 0.1M specific rate constants of reaction at k0 = (4.9±0.3) × 102 (ascorbic acid)，(5.88± 0.04) × 102 (pyrocatechol)，(6.31± 0.03) × 102 (catechin) ; k1 = (2.78± 0.01) × 107 (ascorbic acid)，(1.32± 0.04)× 1010 (pyrocatechol)，(1.01± 0.01) × 107 (4-nitrocatechol)，(4.68± 0.04) × 109 (catechin), respectively at μ = 1 M HClO4 / LiClO4 and T = 25°C. The reactivities of the catechols were found to be greater than that of the ascorbic acid after the correction of the specific rate constants by the contribution of equilibrium barrier. This implies that the self-exchange rate constants of the catechols are grater than that of the ascorbic acid according to Marcus theory predictive.
