Department of Chemistry , University of Idaho , 875 Perimeter Drive , MS 2343, Moscow , Idaho 83844-2343 , United States.
Department of Chemistry and Physics , Hood College , 401 Rosemont Avenue , Frederick , Maryland 21701-8524 , United States.
J Phys Chem B. 2019 Aug 22;123(33):7137-7148. doi: 10.1021/acs.jpcb.9b04675. Epub 2019 Aug 8.
Two asymmetrically structured model compounds for the hydrogen-generating [Fe-Fe]-hydrogenase active site were investigated to determine the ultrafast photodynamics, structural intermediates, and photoproducts compared to more common symmetric di-iron species. The bidentate-ligand-containing compounds studied were Fe(μ-SCH)(CO)(bipy), , and Fe(μ-SCH)(CO)(phen), , in dilute room temperature acetonitrile solution and low-temperature 2Me-THF matrix isolation using static FTIR difference and time-resolved infrared spectroscopic methods (TRIR). Ultraviolet-visible spectra were also compared to time-dependent density functional theory (TD-DFT) to ascertain the orbital origins of long wavelength electronic absorption features. The spectroscopic evidence supports the conclusions that only a propyl-bridge flip occurs in low-temperature matrix, while early time CO ejection leads to the formation of solvated isomeric species on the 25 ps time scale in room temperature solution.
研究了两种非对称结构的模型化合物，用于研究产氢 [Fe-Fe]-氢化酶活性部位的超快光动力学、结构中间体和光产物，以与更常见的对称二铁物种进行比较。在所研究的双齿配体化合物中，Fe(μ-SCH)(CO)(bipy)， 和 Fe(μ-SCH)(CO)(phen)， 在稀室温乙腈溶液中和低温 2Me-THF 基质隔离中使用静态 FTIR 差谱和时间分辨红外光谱法 (TRIR)进行研究。还将紫外可见光谱与时间相关密度泛函理论 (TD-DFT) 进行了比较，以确定长波长电子吸收特征的轨道起源。光谱证据支持以下结论：只有在低温基质中才会发生丙基桥翻转，而在室温溶液中，早期 CO 逐出会导致在 25 ps 时间尺度上形成溶剂化的异构物种。
