Department of Physics, University of Strathclyde, SUPA, Glasgow G4 0NG, United Kingdom.
J Chem Phys. 2012 Jan 28;136(4):044521. doi: 10.1063/1.3679387.
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.
[FeFe]氢化酶亚基模型（μ-S(CH(2))(3)S)Fe(2)(CO)(4)(PMe(3))(2)的溶液相光化学已经通过超快时间分辨红外光谱和密度泛函理论计算进行了研究。在三种不同的溶剂中，正庚烷、甲醇和乙腈中，通过光解羰基配体形成的三羰基中间体的弛豫导致与热力学上不太稳定的异构形式的成对复合，这表明在不饱和物种中，Fe 中心的配体基团易于相互转化。在极性或氢键溶剂中，这个过程与溶剂取代竞争，导致形成稳定的溶剂加合物物种。这些数据进一步深入了解了在氢酶衍生的仿生化合物中加入非羰基配体对动力学和光化学的影响。
