Photocatalytic Oxygenation Reactions with a Cobalt Porphyrin Complex Using Water as an Oxygen Source and Dioxygen as an Oxidant
Photocatalytic Oxygenation Reactions with a Cobalt Porphyrin Complex Using Water as an Oxygen Source and Dioxygen as an Oxidant
复制标题
DOI：
10.1021/jacs.9b02864
复制
发表时间：
2019-06-12
影响因子：
15
通讯作者：
Fukuzumi, Shunichi
中科院分区：
文献类型：
--
作者：
Hong, Young Hyun;Han, Ji Won;Fukuzumi, Shunichi
在可见光照射下，含钴卟啉配合物Co-II（TPP）的O（2）（-）饱和乙腈溶液中发生六氢吡喃的光催化氧化（TPP 2 =四苯基卟啉二价阴离子）、水和三氟甲磺酸（HOTf）通过单光子-双电子过程，得到五甲基苯甲醇和过氧化氢作为产物，其转化数>6000;在该反应中，H2O和O-2分别用作氧源和双电子氧化剂。通过电子顺磁共振、时间分辨荧光和瞬态吸收测量以及（H2O）-O-18和O-18的O-18-标记实验阐明了光催化机理（2）。据我们所知，我们报告的第一个例子，有效的光催化氧化的有机基质的金属络合物使用H2O作为氧源和O-2作为双电子氧化剂。
Photocatalytic oxygenation of hexamethylbenzene occurs under visible-light irradiation of an O(2)(-)saturated acetonitrile solution containing a cobalt porphyrin complex Co-II(TPP) (TPP2 = tetraphenylporphyrin dianion), water, and triflic acid (HOTf) via a one-photon-two-electron process, affording pentamethylbenzyl alcohol and hydrogen peroxide as products with a turnover number of >6000; in this reaction, H2O and O-2 were used as an oxygen source and a two-electron oxidant, respectively. The photocatalytic mechanism was clarified by means of electron paramagnetic resonance, time-resolved fluorescence, and transient absorption measurements as well as O-18-labeling experiments with (H2O)-O-18 and O-18(2). To the best of our knowledge, we report the first example of efficient photocatalytic oxygenation of an organic substrate by a metal complex using H2O as an oxygen source and O-2 as a two-electron oxidant.