Lichtinitiierte Polymer- und Polymerisationsreaktionen. III. Photoinduzierte Zersetzung von Aryldiazoniumsalzen durch Benzoinderivate |
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Authors: | H. Baumann,U. Mü ller,D. Pfeifer,H.-J. Timpe |
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Abstract: | Light Induced Polymer and Polymerization Reactions. III. Photoinduced Decomposition of Arene Diazonium Salts by Benzoin Derivatives The combination benzoin derivate/arene diazonium salt is suitable as a bivalent photoinitiator system for radicalic and cationic photopolymerization. By means of product analysis, quantum yield measurements and photo-CIDNP-studies a mechanism was proposed including the electron transfer from α-substituted benzyl radicals formed by benzoin derivate photolysis to arene diazonium salts. The quantum yields for diazonium salt decomposition in acetonitril were about 0.65. They show only a small dependence on substituents of diazonium salt but are strong influenced by the solvent. In methanol or dioxane quantum yields were found from 11 to 460. 13C-photo-CIDNP-measurements agree with a mechanism of benzoin ether photolysis on the triplet state. |
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