Substituent Effects in the Iron 2p and Carbon 1s Edge Near-Edge X-ray Absorption Fine Structure Spectroscopy of Metal Arene Complexes and Polymers

Abstract

We have examined the electronic structure of a series of metal arene monomers and polymers by near-edge X-ray absorption fine structure spectroscopy. We observe that electron-donating or -withdrawing substituents have a measurable effect on some features in the NEXAFS spectra of these species. However, more significant changes are observed that arise from strong π*-conjugation between the arene ligand (benzene or cyclopentadienyl) and substituents bonded to this ligand. Spectral features observed in the iron 2p and carbon 1s NEXAFS spectra were assigned with the aid of EHMO and DFT calculations.