The role of oxygen in the hydroxylation reaction of benzene with Fenton's reagent. Oxygen 18 tracer study.
The role of oxygen in the hydroxylation reaction of benzene with Fenton's reagent. Oxygen 18 tracer study.
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DOI：
10.1021/ja00279a057
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发表时间：
1986-09
影响因子：
15
通讯作者：
A. Kunai;S. Hata;S. Ito;K. Sasaki
中科院分区：
文献类型：
--
作者：
A. Kunai;S. Hata;S. Ito;K. Sasaki
研究了在0.05 M H_2SO_4溶液中氧在芬顿试剂催化苯羟基化反应中的作用。主要产物为苯酚和苯醌，摩尔比约为1：1。十比一对苯物料平衡的精确测定表明，苯酚的选择性相当低，小于50%。另一方面，H2O2转化成包括未鉴定的副产物的芳族氧化产物的转化率出乎意料地高。用（'802）2气体作示踪剂的研究表明，苯酚中的同位素掺入量约为0.001。20%，而在苯醌中的掺入是完美的。实验还表明，在反应过程中，氧气和苯的消耗量均超过H2 0 2。为了解释所有这些结果，提出了Dorfman机理导致的H2 0 2再生。借助于计算机模拟，再生的H2O2的量估计为最初使用的H2O2的约20%。并对影响苯酚同位素掺入的因素进行了讨论。
The role of oxygen in the hydroxylation of benzene with Fenton's reagent was studied in a 0.05 M H2S0, solution. The main products are phenol and benzoquinone in the molar ratio ca. 10: 1. A precise determination of material balance with respect to benzene indicated that the selectivity of phenol is rather low, less than 50%. On the other hand, the conversion of H 2 0 2 into aromatic oxidation products including unidentified byproducts is unexpectedly high. Tracer study with ('802)2 gas indicated that the isotope incorporation in phenol is ca. 20%, while the incorporation in benzoquinone is perfect. It was also shown that both oxygen and benzene were consumed in excess of H 2 0 2 during the reaction. To account for all of these results, regeneration of H 2 0 2 resulting from Dorfman's mechanism has been proposed. By the aid of computer simulation, the amount of H202 regenerated was estimated to be around 20% of H202 initially used. Factors affecting the isotope incorporation in phenol were also discussed.