Chinese Journal of Catalysis ›› 2015, Vol. 36 ›› Issue (11): 2011-2019.DOI: 10.1016/S1872-2067(15)60920-2

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Synthesis, characterization and catalytic reactivity of pentacoordinate iron dicarbonyl as a model of the [Fe]-hydrogenase active site

Tianyong Zhanga,b, Liao Shenga, Qiusheng Yangc, Shuang Jianga, Yanhong Wanga, Chaohui Jina, Bin Lia   

  1. a Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China;
    b Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China;
    c School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
  • Received:2015-04-16 Revised:2015-05-23 Online:2015-11-02 Published:2015-11-02
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21103121, 21276187), Tianjin Municipal Natural Science Foundation (13JCQNJC05800) and the Specialized Research Fund for the Doctoral Program of Higher Education (20121317110009).

Abstract:

Two mono iron complexes Fe(CO)2PR3(NN) (R = Cy (3), Ph (4), NN = o-phenylenediamine dianion ligand, N2H2Ph2-) derived from the ligand substitution of Fe(CO)3I2PR3 by the NN ligand were isolated and structurally characterized by single crystal X-ray diffraction. They have a similar first coordination sphere and oxidation state of the iron center as the [Fe]-hydrogenase active site, and can be a model of it. IR demonstrated that the effect of the NN ligand on the coordinated CO stretching frequencies was due to its excellent electron donating ability. The reversible protonation/deprotonation of the NN ligand was identified by infrared spectroscopy and density functional theory computation. The NN ligand is an effective proton acceptor as the internal base of the cysteine thiolate ligand in [Fe]-hydrogenase. The electrochemical properties of complexes 3, 4 were investigated by cyclic voltammograms. Complex 3 catalyzed the transfer hydrogenation of benzoquinone to hydroquinone effectively under mild conditions.

Key words: Mono iron hydrogenase, Model complex, Catalytic transfer hydrogenation, Functional analogue, Benzoquinone