Heteroleptic Copper Photosensitizers: Why an Extended π-System Does Not Automatically Lead to Enhanced Hydrogen Production
Heteroleptic Copper Photosensitizers: Why an Extended π-System Does Not Automatically Lead to Enhanced Hydrogen Production
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DOI：
10.1002/chem.201604005
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发表时间：
2017-01-05
影响因子：
4.3
通讯作者：
Karnahl, Michael
中科院分区：
文献类型：
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作者：
Heberle, Martin;Tschierlei, Stefanie;Karnahl, Michael
合成了一系列在二亚胺配体骨架上具有扩展p-体系的[（（PP）-P-boolean AND）Cu（（NN）-N-boolean AND）]（+）型杂配铜（I）光敏剂。所有配合物的结构完全通过NMR光谱，质谱和X射线晶体学表征。在三乙胺和[Fe-3（CO）（12）]存在下，就质子的光催化还原评估这些新型光敏剂。虽然固态结构和计算结果表明，π-扩展的结构性能没有显着的影响，减少活动观察。为了解释这种下降，电化学和电物理测量的组合，包括时间分辨发射以及瞬态吸收光谱在飞秒到纳秒的时间制度被使用。因此，由位于二亚胺配体处的激发态的快速减少引起的激发态寿命缩短被确定为光催化性能低的主要原因。
A series of heteroleptic copper(I) photosensitizers of the type [((PP)-P-boolean AND)Cu((NN)-N-boolean AND)](+) with an extended p-system in the backbone of the diimine ligand has been prepared. The structures of all complexes are completely characterized by NMR spectroscopy, mass spectrometry, and X-ray crystallography. These novel photosensitizers were assessed with respect to the photocatalytic reduction of protons in the presence of triethylamine and [Fe-3(CO)(12)]. Although the solidstate structures and computational results show no significant impact of the pi-extension on the structural properties, decreased activities were observed. To explain this drop, a combination of electrochemical and photophysical measurements including time-resolved emission as well as transient absorption spectroscopy in the femto- to nanosecond time regime was used. Consequently, shortened excited state lifetimes caused by the rapid depopulation of the excited states located at the diimine ligand are identified as a major reason for the low photocatalytic performance.