Flash photolysis/HPLC applications. 2. Direct photolysis vs. hydrogen peroxide mediated photodegradation of 4-chlorophenol as studied by a flash photolysis/HPLC technique

摘要: ~~~~~ ~~~ A method involving UV flash photolysis followed shortly by HPLC analysis of products has been applied to the study partial photooxidation 4-chlorophenol (I). In this we have compared distribution photoproducts obtained under conditions hydrogen peroxide mediation with our earlier reported work on direct I. There it was found that I, stimulated single flashes, yields quantitative amounts p-benzoquinone (11) as only primary photoproduct. When concentration H202 is increased greater than 20 times produds change over a different set. Now major product 4-chlorocatechol (VI) smaller hydroquinone (IV) and 1,2,4-trihydroxybenzene (V). several flashes are applied, IV V become most significant products; however, overall yield IV-VI decreases, indicating further oxidative degradation reaction mixture occurring.