基于非贵金属镍的金属有机大环的光解水放氢性能（英文）

Construction of a Noble-Metal-Free Nickel Metal-Organic Macrocycle for Photocatalytic Hydrogen Production

将具有NN(氮氮)双齿配位点的席夫碱配体L2(L2=1,4-苯二-2′-吡啶腙)与镍构筑得到一例[2+2]型金属有机大环[Ni_2(L_2)_2(CH_3CN)_4](ClO_4)_4·4CH_3CN(2),并将其用于可见光条件下的光解水产氢研究。该非贵金属光催化体系由催化剂、光敏剂(荧光素,Fl)和电子牺牲剂(三乙胺)三部分组成。相比于具有相同配位环境的单核配合物[Ni(L_1)_2(CH_3CN)_2](ClO_4)2(1,L1=3-甲酰基苯-2′-吡啶腙),金属有机大环2作为催化剂具有较高的光催化活性,其产氢TON值可以达到3 100 molH_2·molcat-1,归因于荧光素分子可能与金属有机大环2形成超分子配合物,提高了光致电子转移效率。

A nickel based metal-organic macrocycle[Ni2（L2）2（CH3CN）4]（ClO4）4·4CH3CN （2） constructed from bidentate Schiff base ligand L2 （L2=1,4-benzenedicarboxaldehyde-bis（2＇-pyridinylhydrazone）） with multiple N atoms was utilized to produce hydrogen through splitting of water by visible light （λ〉400 nm）. This noble-metal-free photocatalytic system consists of a catalyst, photosensitizer （fluorescein, Fl） and sacrificial electron donor （Triethylamine, NEt3）. Using the metal-organic macrocycle 2 as a proton reduction catalyst, the activity of the photocatalytic system is high, with a turnover number （TON） of approximately 3 100 molH2·molcat^-1. In contrast to the metal-organic macrocycle 2, a mononuclear complex[Ni（L1）2（CH3CN）2]（ClO4）2 （1, L1=3-formyl benzaldehyde-2＇-pyridylhydrazone） with similar coordination environment has a low efficiency on producing hydrogen. The enhanced efficiency of the catalyst 2 is likely ascribed to the formation of supramolecular complex between fluorescein and the macrocycle which enhances the efficiency of photoinduced electron transfer.