Sub-electron-volt chemical shifts and strong interference effects measured in the resonance x-ray scattering spectra of aniline

Abstract

By exploring the monosubstituted benzene compound aniline, we demonstrate that resonance inelastic x-ray spectroscopy of chemically shifted species is site selective. Core-excited levels with distinct, super-electron-volt shifts can be resonantly excited and their x-ray emission spectra analyzed separately. Core-excited levels referring to sites with small, sub-electron-volt, chemical shifts give resonant x-ray spectra that interfere strongly. It is demonstrated that this interference, which is manifested in the one-step model, can be used to monitor chemical shifts in the sub-electron-volt energy region. We show that in the limit when these chemical shifts go to zero some salient symmetry-selective features of the benzene resonant x-ray emission spectrum are restored in the aniline spectra.