Direct observation of benzoyloxyl radicals in photodecomposition of dibenzoyl peroxides with a time-resolved ESR technique
Direct observation of benzoyloxyl radicals in photodecomposition of dibenzoyl peroxides with a time-resolved ESR technique
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利用时间分辨 ESR 技术直接观察过氧化二苯甲酰光分解中的苯甲酰氧基自由基
DOI：
10.1021/ja00303a047
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
K. Tokumaru
中科院分区：
文献类型：
--
作者：
S. Yamauchi;N. Hirota;Shigeru Takahara;H. Sakuragi;K. Tokumaru
在低功率（<0.1mW）下观察到EPR信号的衰减，以避免自旋-自旋重激发的复杂性。[15]得到的重要结果是，自由基1的衰减时间与自由基2的上升时间完全一致。对于自由基3和4也发现了类似的关系。这些结果表明，逐步过程发生在自由基1和2之间和自由基3和4之间。我们得到的衰减时间（r）为0.25，0.72，和1.6毫秒，在20 ℃的苯甲酰氧基自由基产生的BPO，Cl-BPO，和MeO-BPO，分别。这些衰变时间被认为是这些自由基的寿命，原因如下。首先，这些值比通常在溶液中获得的自旋-晶格弛豫（SLR）时间（几微秒）短得多。第二，
The decays of the EPR signals were observed at low microwave powers (< 0.1 mW) to avoidcomplication due to spin-spin re-laxation. 15 The important result obtained is that the decay time of radical 1 is in good agreement with the rise time of radical 2. A similar relation was also found for radicals 3 and 4. These results suggest that the stepwise processes occur between radicals 1 and 2 and radicals 3 and 4. We obtained the decay times (r) of 0.25, 0.72, and 1.6 ms at 20 C for the benzoyloxyl radicals produced from BPO, Cl-BPO, and MeO-BPO, respectively. These decay times are considered to be the lifetimes of these radicals for the following reasons. First, thevalues are much shorter than those (several microseconds) usually obtained for spin-lattice relaxation (SLR) times in solution. Second, therelation of