Abstract
Iron porphyrins are the active sites of many natural and artificial catalysts, and their photoinduced dynamics have been described as either relaxation into a vibrationally hot ground state or as a cascade through metal-centered states. In this work, we directly probe the metal center of iron(III) tetraphenyl porphyrin chloride (FeTPPCl) using femtosecond M2,3-edge X-ray absorption near-edge structure (XANES) spectroscopy. Photoexcitation at 400 nm produces a (π,π*) state that evolves in 70 fs to an iron(II) ligand-to-metal charge transfer (LMCT) state. The LMCT state relaxes to a vibrationally hot ground state in 1.13 ps, without involvement of (d,d) intermediates. The tabletop extreme-ultraviolet probe, combined with semiempirical ligand field multiplet calculations, clearly distinguishes between metal-centered and ligand-centered excited states and resolves competing accounts of Fe(III) porphyrin relaxation. This work introduces tabletop M-edge XANES as a valuable tool for measuring femtosecond dynamics of molecular transition metal complexes in the condensed phase.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
