Heberle Martin, Tschierlei Stefanie, Rockstroh Nils, Ringenberg Mark, Frey Wolfgang, Junge Henrik, Beller Matthias, Lochbrunner Stefan, Karnahl Michael
Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany.
Institute of Physics, University of Rostock, Albert-Einstein-Str. 23, 18059 Rostock, Germany.
Chemistry. 2017 Jan 5;23(2):312-319. doi: 10.1002/chem.201604005. Epub 2016 Dec 1.
A series of heteroleptic copper(I) photosensitizers of the type [(P^P)Cu(N^N)] with an extended π-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 (CO) ]. Although the solid-state structures and computational results show no significant impact of the π-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.
已制备出一系列通式为[(P^P)Cu(N^N)]的杂配铜(I)光敏剂，其二亚胺配体主链中具有扩展的π体系。所有配合物的结构均通过核磁共振光谱、质谱和X射线晶体学进行了全面表征。在三乙胺和[Fe(CO)]存在的情况下，对这些新型光敏剂进行了光催化还原质子的评估。尽管固态结构和计算结果表明π扩展对结构性质没有显著影响，但观察到活性有所降低。为了解释这种下降，采用了电化学和光物理测量相结合的方法，包括飞秒到纳秒时间范围内的时间分辨发射以及瞬态吸收光谱。因此，位于二亚胺配体上的激发态快速去极化导致激发态寿命缩短被确定为光催化性能低的主要原因。
