Quenching of Singlet Oxygen by Oxygen- and Sulfur-Centered Radicals: Evidence for Energy Transfer to Peroxyl Radicals in Solution
作者:Alexandre P. Darmanyan、Daniel D. Gregory、Yushen Guo、William S. Jenks、Laure Burel、Dominique Eloy、Pierre Jardon
DOI:10.1021/ja9730831
日期:1998.1.1
by PhS•, PhSO•, and peroxyl radicals PhOO•, t-BuOO•, PhCH2OO•, Ph2CHOO•, and Ph3COO• was studied in liquid solution. The quantum yields of decomposition of different initiators which lead to the formation of free radicals were measured by using nanosecond transient absorption. This allowed determination of singlet oxygen O2(1Δg) quenching rate constants by the radicals. They are <2 × 108 M-1 s-1 for
在液体溶液中研究了 PhS•、PhSO• 和过氧自由基 PhOO•、t-BuOO•、PhCH2OO•、Ph2CHOO• 和 Ph3COO• 对 1.27 μm 单线态氧发光的淬灭。通过使用纳秒瞬态吸收测量导致自由基形成的不同引发剂分解的量子产率。这允许通过自由基确定单线态氧 O2(1Δg) 淬灭速率常数。对于以硫为中心的自由基,它们是 <2 × 108 M-1 s-1,对于乙腈中的过氧自由基,它们是 (2−7) × 109 M-1 s-1。快速淬灭归因于过氧化物的能量转移淬灭,其具有 n → π* 跃迁,导致其 2A'' 基态上方的低位 2A' 状态。PhSO• 在计算上显示不具有如此低的 2A' 状态。可能有一个非常低的 2B1 状态,对于 PhS•,