The All-Seeing Eye of Resonant Auger Electron Spectroscopy: A Study on Aqueous Solution Using Tender X-rays

Abstract

X-ray absorption and Auger electron spectroscopies are demonstrated to be powerful tools to unravel the electronic structure of solvated ions. In this work for the first time, we use a combination of these methods in the tender X-ray regime. This allowed us to address electronic transitions from deep core levels, to probe environmental effects, specifically in the bulk of the solution since the created energetic Auger electrons possess large mean free paths, and moreover, to obtain dynamical information about the ultrafast delocalization of the core-excited electron. In the considered exemplary aqueous KCl solution, the solvated isoelectronic K and Cl ions exhibit notably different Auger electron spectra as a function of the photon energy. Differences appear due to dipole-forbidden transitions in aqueous K whose occurrence, according to the performed ab initio calculations, becomes possible only in the presence of solvent water molecules.

Hard x-ray photoelectron spectroscopy on heavy atoms and heavy-element containing molecules using synchrotron radiation up to 35 keV at SPring-8 undulator beamlines

“…the resolving power E/ΔE higher than 5000 (where E is the kinetic energy of electron and ΔE the instrumental resolution), are quite scarce. Up to now, the GALAXIES beamline at the SOLEIL synchrotron [2,3] has been the only facility for high-resolution HAXPES experiments on atomic and molecular science and has been achieving significant results on double-core-hole spectroscopy [4][5][6][7], recoil effects [8][9][10], ultrafast phenomena [11][12][13], post-collision interaction (PCI) [14,15], resonant Auger processes [16][17][18][19][20], and very recent studies on aqueous solution [21,22]. The experiments at the GALAXIES beamline, however, are limited to the excitation energy ranging between 2.3 and 12 keV, while experiments with much higher photon energy are quite scarce.…”

Fingerprint of Dipole Moment Orientation of Water Molecules in Cu2+ Aqueous Solution Probed by X-ray Photoelectron Spectroscopy

“…The photoelectron spectrometer is a high-kinetic energy and large-acceptance-angle hemispherical Scienta analyzer, whose lens is colinear to the horizontal polarization axis and perpendicular to the X-ray beam propagation axis . The sample environment is the same as in references , and consists of a glass capillary of 30 μm diameter delivering the liquid as a microjet, placed in front of a temperature-controlled catcher used for liquid extraction. These parts are installed inside a differentially pumped tube facing the lens axis of the spectrometer and having a 2 mm diameter hole for the photons in and a skimmer with a 500 μm hole for the electrons out.…”

The electronic structure of the aqueous permanganate ion: aqueous-phase energetics and molecular bonding studied using liquid jet photoelectron spectroscopy

“…[27][28][29] Further electronic structure insights may be garnered by performing resonantly-enhanced photoelectron spectroscopy (RPES) experiments. 17,30,31 Through excitation at core-to-virtual-valence resonances, signals from solutes with relatively low ionization cross-sections or local concentrations can be selectively enhanced and detected. 32 Furthermore, the energetics of resonant (valence) photoelectron signals generated following core-to-virtual-valence excitation and solute intramolecular relaxation allow the atomic parentages of specific molecular bonding interactions to be interrogated.…”