title: The role of CN and CO ligands in the vibrational relaxation dynamics of model compounds of the [FeFe]-hydrogenase enzyme.
abstract: The vibrational dynamics of (μ-propanedithiolate)Fe(2)(CO)(4)(CN)(2)(2-), a model compound of the active site of the [FeFe]-hydrogenase enzyme, have been examined via ultrafast 2D-IR spectroscopy. The results indicate that the vibrational coupling between the stretching modes of the CO and CN ligands is small and restricted to certain modes but the slow growth of off-diagonal peaks is assigned to population transfer processes occurring between these modes on timescales of 30-40 ps. Analysis of the dynamics in concert with anharmonic density functional theory simulations shows that the presence of CN ligands alters the vibrational relaxation dynamics of the CO modes in comparison to all-carbonyl model systems and suggests that the presence of these ligands in the enzyme may be an important feature in terms of directing the vibrational relaxation mechanism.
authors.affiliation: Dept. of Physics, University of Strathclyde, SUPA, 107 Rottenrow East, Glasgow, UK.
authors.forename: Spyridon
authors.initials: S
authors.lastname: Kaziannis
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Wright
authors.forename: Marco
authors.initials: M
authors.lastname: Candelaresi
authors.forename: Rafal
authors.initials: R
authors.lastname: Kania
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Greetham
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* / Q000378:metabolism; D002248:Carbon Monoxide / Q000378:metabolism*; D020134:Catalytic Domain; D003486:Cyanides / Q000378:metabolism*; D006864:Hydrogenase / Q000737:chemistry* / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000737:chemistry* / Q000378:metabolism; D008024:Ligands; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D003486:Cyanides; D007506:Iron-Sulfur Proteins; D008024:Ligands; D002248:Carbon Monoxide; D006864:Hydrogenase