Photoinitiators and photoinitiation, 8 The photoinduced α‐cleavage of acylphosphine oxides. Identification of the initiating radicals using a model substrate
Photoinitiators and photoinitiation, 8 The photoinduced α‐cleavage of acylphosphine oxides. Identification of the initiating radicals using a model substrate
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光引发剂和光引发，8 酰基氧化膦的光诱导 α-裂解使用模型底物识别引发自由基。
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
T. Overeem
中科院分区：
文献类型：
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作者：
J. E. Baxter;R. Davidson;H. J. Hageman;T. Overeem
研究了二苯基-2,4,6-三甲基苯甲酰基氧化膦 (1) 在 40°C 溶液中和在 1,1-二对甲苯乙烯作为乙烯基单体模型基质存在的薄膜中的光分解。发现由 1 的 α-裂解产生的两个主要自由基都添加到模型底物的烯属双键上（引发）。事实证明，在所有条件下，二苯基膦酰基自由基 (3) 的效率是 2,4,6-三甲基苯甲酰基自由基 (2) 的两倍。氧气（空气）显着降低了引发效率fp，特别是fp(2)（自由基2）。添加三乙胺很可能通过氧清除部分恢复了总体引发效率。没有观察到三乙胺衍生的自由基对引发的直接贡献。
The photodecomposition of diphenyl-2,4,6-trimethylbenzoylphosphine oxide (1) was studied both in solution at 40°C and in thin films in the presence of 1,1-di-p-tolylethylene as a model substrate for vinyl monomers. Both primary radicals resulting from α-cleavage of 1 were found to add to the olefinic double bond of the model substrate (initiation). The diphenylphosphinoyl radical (3) proved to be twice as effective as the 2,4,6-trimethylbenzoyl radical (2) under all conditions. Oxygen (air) considerably reduced the initiating efficiencies fp, in particular fp(2) (of radical 2). The addition of triethylamine partially restored the overall initiating efficiency in all likelihood by oxygen scavenging. A direct contribution of triethylamine-derived radicals to the initiation was not observed.