Electron dynamics and energy transfer in aqueous solution revealed by resonant core-hole electron spectroscopy

PHYS 267

Bernd Winter, winter@bessy.de1, Emad F Aziz, emad@bessy.de1, Manfred Faubel, manfred.faubelqds.mpg.de2, Nobuhiro Kosugi, kosugi@ims.as.jp3, and Ingolf V. Hertel, hertel@mbi-berlin.de4. (1) BESSY, Albert-Eintstein Str. 15, Berlin, 12489, Germany, (2) Max-Planck-Institut für Dynamik und Selbstorganisation, Bunsenstrasse 10, Göttingen, 37073, Germany, (3) Institute for Molecular Science, Myodaiji, Okazaki, 444-8585, Japan, (4) Max-Born -Institut, Max-Born-Strasse 2A, Berlin, 12489, Germany
Resonant Auger-electron spectroscopy has been applied to investigate charge-transfer-to-solvent (CTTS) processes in chloride aqueous solutions. A series of CTTS states is identified through the occurrence of characteristic spectator Auger decays after 2p core-hole excitation. In addition the electron relaxation to the lowest CTTS state as revealed through shakedown-type processes, suggests a coupling of the CTTS electron to the solution conduction band. Similar studies of aqueous hydroxide show no such spectator Auger peaks upon O1s excitation, but rather exhibit spectral features characteristic of intermolecular energy-transfer autoionization. The occurrence of such a mechanism is a result of the unique solvation structure of the OH- anion, which provides unambiguous evidence for the existence of the OH- hydrogen donor-bond.