Synthesis, characterization and electrochemical properties of diiron azadithiolate complexes Fe2[(μ-SCH2)2NCH2CCH](CO)5 L (L = CO or monophosphines)

Diiron azadithiolate complexes are considered as important biomimetic models for the diiron subsite of [FeFe]-hydrogenases. Here, the diiron azadithiolate complex Fe-2[(mu-SCH2)(2)NCH2CCH](CO)(6) (1), produced by the condensation reaction of Fe-2[(mu-SCH2OH)(2)(CO)(6) and NH2CH2CCH, is described. Meanwhile, the corresponding phosphine-substituted diiron azadithiolate complexes Fe-2[(mu-SCH2)(2)NCH2CCH](CO)(5)L (2-6) = PPh3, P(C6H4-4-CH3)(3), P(C6H4-4-OCH3)(3), P(-2-C4H3O)(3), PPh2C6H11] have been successfully prepared by the reactions of Fe-2[(mu-SCH2OH)(2)(CO)(5)L and NH2CH2CCH. All the new complexes 1-6 were fully characterized by elemental analysis, IR, UV/Vis, NMR spectroscopy, and for 1, 3, 4, 5 and 6 by X-ray single-crystal diffraction analysis. In addition, complexes 1-6 are all found to be active catalysts for H-2 production under electrochemical conditions. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study describes the synthesis and characterization of a diiron azadithiolate complex and its corresponding phosphine-substituted derivatives, which were found to be active catalysts for H-2 production under electrochemical conditions.