Photodynamics of [FeFe]-Hydrogenase Model Compounds with Bidentate Heterocyclic Ligands

Published

July 23, 2019

Author(s)

Wyatt Thornley, Sarah Wirick, Maximilian Riedel-Topper, Nathan J. DeYonker, Thomas E. Bitterwolf, Christopher J. Stromberg, Edwin J. Heilweil

Abstract

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 Fe2(μ-S2C3H6)(CO)4(bpy), 1, and Fe2(μ- S2C3H6)(CO)4(phen), 2, 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 formation of solvated isomeric species on the 100 ps timescale.

Citation

Journal of Physical Chemistry B

Volume

123

Issue

33

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acs.jpcb.9b04675

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Keywords

Di-iron hydrogenase models, density functional theory, matrix isolation, photo-isomerization dynamics, solution-phase, time-resolved infrared, ultrafast infrared spectroscopy, vibrations

Citation

Thornley, W. , Wirick, S. , Riedel-Topper, M. , DeYonker, N. , Bitterwolf, T. , Stromberg, C. and Heilweil, E. (2019), Photodynamics of [FeFe]-Hydrogenase Model Compounds with Bidentate Heterocyclic Ligands, Journal of Physical Chemistry B, [online], https://doi.org/10.1021/acs.jpcb.9b04675, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=928030 (Accessed October 10, 2025)