Natali Mirco, Badetti Elena, Deponti Elisa, Gamberoni Marta, Scaramuzzo Francesca A, Sartorel Andrea, Zonta Cristiano
Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17-19, 44121 Ferrara, Italy.
Dalton Trans. 2016 Oct 7;45(37):14764-73. doi: 10.1039/c6dt01705c. Epub 2016 Jul 20.
Hydrogen production from water splitting is nowadays recognized as a target, fundamental reaction for the production of clean fuels. Indeed, tremendous efforts have been devoted towards the research of suitable catalysts capable of performing this reaction. With respect to heterogeneous systems, molecular catalysts such as metal complexes are amenable to chemical functionalization in order to fine tune the catalytic properties. In this paper a new class of tris(2-pyridylmethyl)-amine (TPMA) cobalt(ii) complexes (CoL0-4) has been synthesized and employed as hydrogen evolving catalysts under photochemical conditions taking advantage of Ru(bpy)3(2+) (where bpy is 2,2'-bipyridine) as a light-harvesting sensitizer and ascorbic acid as a sacrificial electron donor. Tuning of the photocatalytic activity has been attempted through the introduction of different substituents at the catalyst periphery rather than through a direct chemical modification of the chelating TPMA ligand. The results show that CoL0-4 behave as competent hydrogen evolving catalysts (HECs), although the effects played by the different substituents on the catalysis are relatively modest. Possible reasons supporting the observed behavior as well as possible improvements of the aforementioned tuning approach are discussed.
如今，水分解制氢被视为生产清洁燃料的一个目标性的基础反应。事实上，人们已经在致力于研究能够进行该反应的合适催化剂方面付出了巨大努力。相对于多相体系，诸如金属配合物之类的分子催化剂易于进行化学官能化，以便微调催化性能。在本文中，一类新型的三（2-吡啶甲基）胺（TPMA）钴（II）配合物（CoL0-4）已被合成，并在光化学条件下用作析氢催化剂，利用Ru（bpy）3（2+）（其中bpy为2,2'-联吡啶）作为光捕获敏化剂，抗坏血酸作为牺牲电子供体。已尝试通过在催化剂周边引入不同取代基而非通过对螯合TPMA配体进行直接化学修饰来调节光催化活性。结果表明，CoL0-4表现为有能力的析氢催化剂（HEC），尽管不同取代基对催化作用的影响相对较小。讨论了支持所观察到行为的可能原因以及上述调节方法可能的改进。
