These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Effects of cations on the hydrogen bond network of liquid water: new results from X-ray absorption spectroscopy of liquid microjets.
    Author: Cappa CD, Smith JD, Messer BM, Cohen RC, Saykally RJ.
    Journal: J Phys Chem B; 2006 Mar 23; 110(11):5301-9. PubMed ID: 16539461.
    Abstract:
    Oxygen K-edge X-ray absorption spectra (XAS) of aqueous chloride solutions have been measured for Li(+), Na(+), K(+), NH(4)(+), C(NH(2))(3)(+), Mg(2+), and Ca(2+) at 2 and 4 M cation concentrations. Marked changes in the liquid water XAS are observed upon addition of the various monovalent cation chlorides that are nearly independent of the identity of the cation. This indicates that interactions with the dissolved monovalent cations do not significantly perturb the unoccupied molecular orbitals of water molecules in the vicinity of the cations and that water-chloride interactions are primarily responsible for the observed spectral changes. In contrast, the addition of the divalent cations engenders changes unique from the case of the monovalent cations, as well as from each other. Density functional theory calculations suggest that the ion-specific spectral variations arise primarily from direct electronic perturbation of the unoccupied orbitals due to the presence of the ions, probably as a result of differences in charge transfer from the water molecules onto the divalent cations.
    [Abstract] [Full Text] [Related] [New Search]