Tandem redox mediator/Ni(ii) trihalide complex photocycle for hydrogen evolution from HCl.
Tandem redox mediator/Ni(ii) trihalide complex photocycle for hydrogen evolution from HCl.
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DOI：
10.1039/c4sc02357a
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发表时间：
2015-02-01
期刊：
影响因子：
8.4
通讯作者：
Nocera DG
中科院分区：
文献类型：
--
作者：
Hwang SJ;Powers DC;Maher AG;Nocera DG
第一行过渡金属络合物的短激发态寿命对M-X键的光活化的挑战已经用偶联到镍金属催化剂的膦介体克服。M-X键的光活化对于光化学HX分裂是一个挑战，特别是对于第一行过渡金属络合物，因为短的固有激发态寿命。在此，我们报告了串联H2光循环的基础上的组合的非碱性光氧化还原膦介体和镍金属催化剂。合成研究和时间分辨的光化学研究表明，膦作为光化学H-原子供体Ni（ii）三卤化物配合物，提供一个Ni（i）中心。通过Ni（i）的顺序反硝化以提供Ni（0）和Ni（ii）以及从Ni（0）中间体的质子水解H2释放来关闭H2释放催化循环。这些调查的结果表明，H2光生收益由两个连续的催化循环：由膦催化的光氧化还原循环和由Ni配合物催化的H2-演化循环，以规避与第一行过渡金属配合物的光化学的挑战。
The challenge that short excited state lifetimes of first-row transition metal complexes present to the photoactivation of M–X bonds has been overcome with a phosphine mediator coupled to a nickel metal catalyst. Photoactivation of M–X bonds is a challenge for photochemical HX splitting, particularly with first-row transition metal complexes because of short intrinsic excited state lifetimes. Herein, we report a tandem H2 photocycle based on combination of a non-basic photoredox phosphine mediator and nickel metal catalyst. Synthetic studies and time-resolved photochemical studies have revealed that phosphines serve as photochemical H-atom donors to Ni(ii) trihalide complexes to deliver a Ni(i) centre. The H2 evolution catalytic cycle is closed by sequential disproportionation of Ni(i) to afford Ni(0) and Ni(ii) and protolytic H2 evolution from the Ni(0) intermediate. The results of these investigations suggest that H2 photogeneration proceeds by two sequential catalytic cycles: a photoredox cycle catalyzed by phosphines and an H2-evolution cycle catalyzed by Ni complexes to circumvent challenges of photochemistry with first-row transition metal complexes.
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DOI：
10.1107/s0108270100008350
发表时间：
2000-09-01
影响因子：
0.8
作者：
Ellis, DD;Spek, AL
通讯作者：
Spek, AL
影响因子：
4
作者：
Lee, Chang Hoon;Lutterman, Daniel A.;Nocera, Daniel G.
通讯作者：
Nocera, Daniel G.
影响因子：
15
作者：
Powers, David C.;Anderson, Bryce L.;Nocera, Daniel G.
通讯作者：
Nocera, Daniel G.
影响因子：
4.6
作者：
Nocera, Daniel G.
通讯作者：
Nocera, Daniel G.
影响因子：
2.8
作者：
Haav, Kristjan;Saame, Jaan;Leito, Ivo
通讯作者：
Leito, Ivo