Panagiotopoulos Athanassios, Ladomenou Kalliopi, Sun Dongyue, Artero Vincent, Coutsolelos Athanassios G
Laboratory of Bioinorganic Chemistry, Department of Chemistry, University of Crete, Voutes Campus, 70013 Heraklion, Crete, Greece.
Laboratoire de Chimie et Biologie des Métaux, Université Grenoble Alpes, CNRS, CEA, 17 rue des Martyrs, 38000 Grenoble, France.
Dalton Trans. 2016 Apr 21;45(15):6732-8. doi: 10.1039/c5dt04502a.
We report on the first systematic study of cobaloxime-based hydrogen photoproduction in mixed pH 7 aqueous/acetonitrile solutions and demonstrate that H2 evolution can be tuned through electronic modifications of the axial cobalt ligand or through introduction of TiO2 nanoparticles. The photocatalytic systems consist of various cobaloxime catalysts [Co(dmgH)2(L)Cl] (L = nitrogen-based axial ligands) and a water soluble porphyrin photosensitizer. They were assayed in the presence of triethanolamine as a sacrificial electron donor. Optimal turnover numbers related to the photosensitizer are obtained with electron-rich axial ligands such as imidazole derivatives (1131 TONs with N-methyl imidazole). Lower stabilities are observed with various pyridine axial ligands (443 TONs for para-methylpyridine), especially for those containing electron-acceptor substituents. Interestingly, when L is para-carboxylatopyridine the activity of the system is increased from 40 to 223 TONs in the presence of TiO2 nanoparticles.
我们报道了在pH值为7的混合水/乙腈溶液中基于钴肟的光催化产氢的首次系统研究，并证明可以通过轴向钴配体的电子修饰或通过引入二氧化钛纳米颗粒来调节氢气的析出。光催化体系由各种钴肟催化剂[Co(dmgH)2(L)Cl]（L = 基于氮的轴向配体）和一种水溶性卟啉光敏剂组成。它们在作为牺牲电子供体的三乙醇胺存在下进行了测定。使用富电子轴向配体（如咪唑衍生物）可获得与光敏剂相关的最佳周转数（与N-甲基咪唑相关的周转数为1131）。各种吡啶轴向配体的稳定性较低（对甲基吡啶的周转数为443），特别是对于那些含有电子受体取代基的配体。有趣的是，当L为对羧基吡啶时，在存在二氧化钛纳米颗粒的情况下，体系的活性从40提高到223个周转数。
