Tertiary phosphine disubstituted diiron bis(monothiolate) carbonyls related to the active site of [FeFe]-H2ases: Preparation, protonation and electrochemical properties

As biomimetic models of the active site of [FeFe]-H(2)ases, two electron-rich, PR3 -disubstituted diiron bis(monothiolate) carbonyls Fe-2 (mu-SBn)(2) (CO)(4)L-2 (Bn = CH2 Ph, L = PPhMe2 , 1; PMe3 , 2) have been prepared. To further mimic the structural and functional models for the protonated diiron subsite, the mu-hydride diiron compounds [(mu-H)Fe-2(mu-SBn)(2)(CO)(4)L-2] BF4 (L = PPhMe2, 1-H+; and PMe3, 2-H+) were prepared by protonation reactions of 1 and 2 with HBF4 center dot Et2O. All the compounds were characterized by elemental analysis, FT-IR, NMR spectroscopy, and particularly for 1, 2 and 2-H+ by X-ray diffraction analyses. Furthermore, the electrochemical properties of 1 and 2 are studied by cyclic voltammetry (CV) in MeCN, 1 has been found to be catalyst for H-2 production in the presence of acetic acid (HOAc).

Automated summary

Two electron-rich, PR3-disubstituted diiron bis(monothiolate) carbonyls were prepared as biomimetic models of the active site of [FeFe]-H(2)ases. Mu-hydride diiron compounds were also synthesized as structural and functional models for the protonated diiron subsite. Characterization and electrochemical property studies were conducted for all compounds, with one compound found to catalyze H-2 production in the presence of acetic acid.