title: Mechanistic aspects of the protonation of [FeFe]-hydrogenase subsite analogues.
abstract: The formation of transient metal hydride(s) at the metallo-sulfur active sites of [FeFe]-hydrogenase is implicated in both hydrogen evolution and uptake reactions. Using a combination of time-resolved NMR, stopped-flow UV and stopped-flow IR, we have begun to unravel the mechanisms for protonation of synthetic electron-rich analogues of the di-iron subsite of the enzyme: Fe(2)(mu-pdt)(CO)(4)(PMe(3))(2), Fe(2)(mu-edt)(CO)(4)(PMe(3))(2), (NEt(4))(2)[Fe(2)(mu-pdt)(CO)(4)(CN)(2)], (NEt(4))(2)[Fe(2)(mu-edt)(CO)(4)(PMe(3))(2)] and (NEt(4))[Fe(2)(mu-pdt)(CO)(4)(CN)(PMe(3))] (pdt = propane-1,3-dithiolate, edt = ethane-1,2-dithiolate). The mechanistic role of isomer interconversion and how this critically relates to steric access to the di-iron bridge are revealed.
authors.affiliation: Energy Materials Laboratory, School of Chemistry, University of East Anglia, Norwich, United Kingdom NR4 7TJ.
authors.forename: Ausra
authors.initials: A
authors.lastname: Jablonskyte
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Wright
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Pickett
mesh_terms: D003486:Cyanides / Q000737:chemistry; D006864:Hydrogenase / Q000737:chemistry*; D007506:Iron-Sulfur Proteins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D010720:Phosphines / Q000737:chemistry; D011522:Protons
chemical_list: D003486:Cyanides; D007506:Iron-Sulfur Proteins; D010720:Phosphines; D011522:Protons; C118830:iron hydrogenase; D006864:Hydrogenase