Optimization of Hydrogen-Evolving Photochemical Molecular Devices
Optimization of Hydrogen-Evolving Photochemical Molecular Devices
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DOI：
10.1002/anie.201409442
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发表时间：
2015-05-26
影响因子：
16.6
通讯作者：
Rau, Sven
中科院分区：
文献类型：
--
作者：
Pfeffer, Michael G.;Kowacs, Tanja;Rau, Sven
由Ru-II光中心、四苯并吩嗪桥联配体和PtX2(X=Cl或I)部分组成的分子光催化剂是光驱动制氢的稳定体系。这种光化学分子器件(PMD)通过将铂中心的末端氯化物交换为碘配体而显著提高了催化活性。超快瞬时吸收光谱表明，分子内光物理不受这种变化的影响。此外，一般的催化行为，即瞬间形成氢，恒定的翻转频率，和稳定性保持不变。与观察到的Pd类似物不同，过量卤化物的存在不会影响PMD的产氢能力。催化效率的显著提高是由于铂催化中心电子密度的增加，DFT研究证实了这一点。
A molecular photocatalyst consisting of a Ru-II photocenter, a tetrapyridophenazine bridging ligand, and a PtX2 (X=Cl or I) moiety as the catalytic center functions as a stable system for light-driven hydrogen production. The catalytic activity of this photochemical molecular device (PMD) is significantly enhanced by exchanging the terminal chlorides at the Pt center for iodide ligands. Ultrafast transient absorption spectroscopy shows that the intramolecular photophysics are not affected by this change. Additionally, the general catalytic behavior, that is, instant hydrogen formation, a constant turnover frequency, and stability are maintained. Unlike as observed for the Pd analogue, the presence of excess halide does not affect the hydrogen generation capacity of the PMD. The highly improved catalytic efficiency is explained by an increased electron density at the Pt catalytic center, this is confirmed by DFT studies.