Diiron dithiolate complexes containing intra-ligand NH center dot center dot center dot S hydrogen bonds: FeFe hydrogenase active site models for the electrochemical proton reduction of HOAc with low overpotential
2008 (English)In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, no 18, 2400-2406 p.Article in journal (Refereed) Published
Four diiron dithiolate complexes containing ortho- acylamino- functionalized arenethiolato ligands, [(mu-S-2-RCONHC6H4)(2)Fe-2(CO)(6)] (R=CH3, 1; CF3, 2; C6H5, 3; 4-FC6H4, 4), were synthesized and well characterized as biomimetic models of the Fe-Fe hydrogenase active site. The molecular structures of 3 and 4 were determined by X-ray crystallography. The intra-ligand NH center dot center dot center dot S hydrogen bonds were studied by the X-ray analysis and by the H-1 NMR spectroscopy. The contribution of the NH center dot center dot center dot S hydrogen bonds to the reduction potentials of complexes 1-4 was investigated by electrochemistry. The first reduction potentials of complexes 1-4 exhibit large positive shifts, that is, 220-320 mV in comparison to that of the analogous complex [(mu- SPh)(2)Fe-2(CO)(6)] and 370-470 mV to that of [(mu- pdt)(2)Fe-2(CO)(6)] (pdt = propane-1,3-dithiolato). Complex 4 is capable of electrocatalysing proton reduction of acetic acid at relatively low overpotential ( ca. 0.2 V) in acetonitrile.
Place, publisher, year, edition, pages
2008. no 18, 2400-2406 p.
IdentifiersURN: urn:nbn:se:kth:diva-17512DOI: 10.1039/b715990kISI: 000255599000007ScopusID: 2-s2.0-43049128178OAI: oai:DiVA.org:kth-17512DiVA: diva2:335556
QC 201005252010-08-052010-08-05Bibliographically approved