Visible-light photoexcitation of pyridine surface complex, leading to selective dehydrogenative cross-coupling with cyclohexane
Visible-light photoexcitation of pyridine surface complex, leading to selective dehydrogenative cross-coupling with cyclohexane
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DOI：
10.1039/c8cp04292f
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发表时间：
2018-12-07
影响因子：
3.3
通讯作者：
Yoshida, Hisao
中科院分区：
文献类型：
--
作者：
Naniwa, Shimpei;Tyagi, Akanksha;Yoshida, Hisao
在可见光的光照射下，吸附在 TiO2 表面的吡啶分子可以被光激发，通过吡啶和钛之间的配体到金属电荷转移 (LMCT) 产生吡啶自由基阳离子。这导致吡啶和环己烷之间发生脱氢交叉偶联（DCC），并伴随析氢。由于自由基阳离子可以选择性地将环己烷氧化成环己基自由基，因此与紫外线照射下TiO2光催化相比，吡啶和环己烷之间的交叉偶联以更高的选择性进行。
Upon photoirradiation with visible light, a pyridine molecule adsorbed on a TiO2 surface can be photoexcited to give a pyridine radical cation via ligand-to-metal charge transfer (LMCT) between pyridine and titanium. This leads to dehydrogenative cross-coupling (DCC) between pyridine and cyclohexane with concomitant hydrogen evolution. Since the radical cation can selectively oxidize cyclohexane to a cyclohexyl radical, the cross-coupling between pyridine and cyclohexane proceeds with higher selectivity compared with that in photocatalysis by TiO2 under UV irradiation.