Covalency-Driven Preservation of Local Charge Densities in a Metal-to-Ligand Charge-Transfer Excited Iron Photosensitizer

Overview

Journal Angew Chem Int Ed Engl

Specialty Chemistry

Date 2019 May 31

PMID 31145507

Citations 7

Authors

Raphael M Jay

Sebastian Eckert

Vinicius Vaz da Cruz

Mattis Fondell

Rolf Mitzner

Alexander Fohlisch

Affiliations

Soon will be listed here.

Abstract

Covalency is found to even out charge separation after photo-oxidation of the metal center in the metal-to-ligand charge-transfer state of an iron photosensitizer. The σ-donation ability of the ligands compensates for the loss of iron 3d electronic charge, thereby upholding the initial metal charge density and preserving the local noble-gas configuration. These findings are enabled through element-specific and orbital-selective time-resolved X-ray absorption spectroscopy at the iron L-edge. Thus, valence orbital populations around the central metal are directly accessible. In conjunction with density functional theory we conclude that the picture of a localized charge-separation is inadequate. However, the unpaired spin density provides a suitable representation of the electron-hole pair associated with the electron-transfer process.

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