title: Probing ion-specific effects on aqueous acetate solutions: Ion pairing versus water structure modifications.
abstract: The effect of monovalent cations (Li(+), K(+), NH4 (+), Na(+)) on the water structure in aqueous chloride and acetate solutions was characterized by oxygen K-edge X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy, and resonant inelastic X-ray scattering (RIXS) of a liquid microjet. We show ion- and counterion dependent effects on the emission spectra of the oxygen K-edge, which we attribute to modifications of the hydrogen bond network of water. For acetates, ion pairing with carboxylates was also probed selectively by XAS and RIXS. We correlate our experimental results to speciation data and to the salting-out properties of the cations.
authors.affiliation: Joint Ultrafast Dynamics Lab in Solutions and at Interfaces (JULiq) , Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany.
authors.forename: Tristan
authors.initials: T
authors.lastname: Petit
authors.affiliation: Joint Ultrafast Dynamics Lab in Solutions and at Interfaces (JULiq) , Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany.
authors.forename: Kathrin M
authors.initials: KM
authors.lastname: Lange
authors.affiliation: Joint Ultrafast Dynamics Lab in Solutions and at Interfaces (JULiq) , Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany.
authors.forename: Gerrit
authors.initials: G
authors.lastname: Conrad
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Joint Ultrafast Dynamics Lab in Solutions and at Interfaces (JULiq) , Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schwanke
authors.affiliation: Joint Ultrafast Dynamics Lab in Solutions and at Interfaces (JULiq) , Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany.
authors.forename: Kai F
authors.initials: KF
authors.lastname: Hodeck
authors.forename: Marcus
authors.initials: M
authors.lastname: Dantz
authors.forename: Tim
authors.initials: T
authors.lastname: Brandenburg
authors.affiliation: Joint Ultrafast Dynamics Lab in Solutions and at Interfaces (JULiq) , Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany.
authors.forename: Edlira
authors.initials: E
authors.lastname: Suljoti
authors.forename: Emad F
authors.initials: EF
authors.lastname: Aziz