Solution-phase photochemistry of a [FeFe]hydrogenase model compound: evidence of photoinduced isomerisation.
The solution-phase photochemistry of the [FeFe] hydrogenase subsite model (μ-S(CH(2))(3)S)Fe(2)(CO)(4)(PMe(3))(2) has been studied using ultrafast time-resolved infrared spectroscopy supported by density functional theory calculations. In three different solvents, n-heptane, methanol, and acetonitrile, relaxation of the tricarbonyl intermediate formed by UV photolysis of a carbonyl ligand leads to geminate recombination with a bias towards a thermodynamically less stable isomeric form, suggesting that facile interconversion of the ligand groups at the Fe center is possible in the unsaturated species. In a polar or hydrogen bonding solvent, this process competes with solvent substitution leading to the formation of stable solvent adduct species. The data provide further insight into the effect of incorporating non-carbonyl ligands on the dynamics and photochemistry of hydrogenase-derived biomimetic compounds.
Department of Physics, University of Strathclyde, SUPA, Glasgow G4 0NG, United Kingdom.
Rafal
R
Kania
Pim W J M
PW
Frederix
Joseph A
JA
Wright
Rein V
RV
Ulijn
Christopher J
CJ
Pickett
Neil T
NT
Hunt
D006864:Hydrogenase / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007536:Isomerism; D008027:Light; D008954:Models, Biological; D044367:Phase Transition; D010777:Photochemistry; D011789:Quantum Theory; D012996:Solutions / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
D012996:Solutions; D007501:Iron; D006864:Hydrogenase