The pyrolyisis of di-tert-butyl peroxyoxalate in the presence of para-substituted benzaldehydes produces almost quantitatively the corresponding p,p'-disubstituted benzils. The formation of these products is accompanied by chemiluminescence arising from excited triplets. From the quantum yield of excited triplet generation and the rate constants for the triplet photocleavage it is possible to obtain the change in Gibbs free energy associated with triplet formation. The values obtained are -5.6, -5.7 and -8.1 kcal/mol for benzil, p,p'-dimethylbenzil and p,p'-dimethoxybenzil, respectively. The pyrolysis of di-tert-butyl peroxyoxalate in the presence of isopropanol or benzoin leads to the formation of acetone and benzil. These products are generated in disproportionation processes involving the alpha-hydroxy radical produced by hydrogen abstraction. The luminescence observed in these reactions constitutes the first experimental indication of excited species generation in the disproportionation of uncorrelated free radicals.

中文翻译：

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激发羰基的形成与自由基的结合和歧化。

在对位取代的苯甲醛的存在下，过氧草酸二叔丁基酯的热解几乎定量地产生了相应的p，p'-二取代的苯甲醚。这些产物的形成伴随着由激发三联体产生的化学发光。从激发三重态产生的量子产率和三重态光解的速率常数，可以得到与三重态形成相关的吉布斯自由能的变化。对于苯，p，p′-二甲基苯和p，p′-二甲氧基苯，所得的值分别为-5.6，-5.7和-8.1kcal / mol。在异丙醇或安息香的存在下，过氧草酸二叔丁酯的热解导致丙酮和苯的形成。这些产物是在歧化过程中产生的，该歧化过程涉及通过夺氢产生的α-羟基自由基。在这些反应中观察到的发光构成了在不相关的自由基歧化中激发物种产生的第一个实验指示。