title: Determination of the photolysis products of [FeFe]hydrogenase enzyme model systems using ultrafast multidimensional infrared spectroscopy.
abstract: Ultrafast transient 2D-IR (T-2D-IR) spectroscopy has been used to study the photolysis products of the [FeFe]hydrogenase enzyme model compound (μ-propanedithiolate)Fe(2)(CO)(6) in heptane solution following irradiation at ultraviolet wavelengths. Observation of coupling patterns between the vibrational modes of the photoproduct species formed alongside examination of the appearance time scales of these signals has uniquely enabled assignment of the photoproduct spectrum to a single pentacarbonyl species. Comparison of the vibrational relaxation rate of the photoproduct with that of the parent is consistent with the formation of a solvent adduct at the vacant coordination site, while anisotropy data in conjunction with density functional theory simulations indicates substitution in an axial rather than equatorial position. No firm evidence of additional short-lived intermediates is seen, indicating that the subsequent chemistry of these species is likely to be strongly defined by the nature of the first solvation shell.
authors.affiliation: Department of Physics, University of Strathclyde, SUPA, 107 Rottenrow East, Glasgow, UK.
authors.forename: Andrew I
authors.initials: AI
authors.lastname: Stewart
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Wright
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Greetham
authors.forename: Spiridon
authors.initials: S
authors.lastname: Kaziannis
authors.forename: Stefano
authors.initials: S
authors.lastname: Santabarbara
authors.forename: Michael
authors.initials: M
authors.lastname: Towrie
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Parker
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Pickett
authors.forename: Neil T
authors.initials: NT
authors.lastname: Hunt
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D006536:Heptanes / Q000737:chemistry; D006864:Hydrogenase / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000378:metabolism*; D008958:Models, Molecular; D008968:Molecular Conformation; D010782:Photolysis; D011407:Propane / Q000031:analogs & derivatives* / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013055:Spectrophotometry, Infrared / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013997:Time Factors; D014732:Vibration
chemical_list: D006536:Heptanes; D007506:Iron-Sulfur Proteins; D012997:Solvents; D013438:Sulfhydryl Compounds; C522648:propanedithiolate; C118830:iron hydrogenase; D006864:Hydrogenase; D011407:Propane