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

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 a

SUBMITTER: Jay RM 

PROVIDER: S-EPMC6771958 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature