title: Structure and vibrational dynamics of model compounds of the [FeFe]-hydrogenase enzyme system via ultrafast two-dimensional infrared spectroscopy.
abstract: Ultrafast two-dimensional infrared (2D) spectroscopy has been applied to study the structure and vibrational dynamics of (mu-S(CH2)3S)Fe2(CO)6, a model compound of the active site of the [FeFe]-hydrogenase enzyme system. Comparison of 2D-IR spectra of (mu-S(CH2)3S)Fe2(CO)6 with density functional theory calculations has determined that the solution-phase structure of this molecule is similar to that observed in the crystalline phase and in good agreement with gas-phase simulations. In addition, vibrational coupling and rapid (<5 ps) solvent-mediated equilibration of energy between vibrationally excited states of the carbonyl ligands of the di-iron-based active site model are observed prior to slower (approximately 100 ps) relaxation to the ground state. These dynamics are shown to be solvent-dependent and form a basis for the future determination of the vibrational interactions between active site and protein.
authors.affiliation: Department of Physics, University of Strathclyde, SUPA, 107 Rottenrow East, Glasgow G4 0NG, UK.
authors.forename: A I
authors.initials: AI
authors.lastname: Stewart
authors.forename: I P
authors.initials: IP
authors.lastname: Clark
authors.forename: M
authors.initials: M
authors.lastname: Towrie
authors.forename: S K
authors.initials: SK
authors.lastname: Ibrahim
authors.forename: A W
authors.initials: AW
authors.lastname: Parker
authors.forename: C J
authors.initials: CJ
authors.lastname: Pickett
authors.forename: N T
authors.initials: NT
authors.lastname: Hunt
mesh_terms: D006864:Hydrogenase / Q000737:chemistry / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000378:metabolism*; D013055:Spectrophotometry, Infrared / Q000379:methods*
chemical_list: D007506:Iron-Sulfur Proteins; C118830:iron hydrogenase; D006864:Hydrogenase