title: (17)O NMR Investigation of Water Structure and Dynamics.
abstract: The structure and dynamics of the bound water in barium chlorate monohydrate were studied with (17)O nuclear magnetic resonance (NMR) spectroscopy in samples that are stationary and spinning at the magic-angle in magnetic fields ranging from 14.1 to 21.1 T. (17)O NMR parameters of the water were determined, and the effects of torsional oscillations of the water molecule on the (17)O quadrupolar coupling constant (CQ) were delineated with variable temperature MAS NMR. With decreasing temperature and reduction of the librational motion, we observe an increase in the experimentally measured CQ explaining the discrepancy between experiments and predictions from density functional theory. In addition, at low temperatures and in the absence of (1)H decoupling, we observe a well-resolved (1)H-(17)O dipole splitting in the spectra, which provides information on the structure of the H2O molecule. The splitting arises because of the homogeneous nature of the coupling between the two (1)H-(17)O dipoles and the (1)H-(1)H dipole.
authors.affiliation: Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Eric G
authors.initials: EG
authors.lastname: Keeler
authors.affiliation: Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Vladimir K
authors.initials: VK
authors.lastname: Michaelis
authors.affiliation: Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Griffin
mesh_terms: D017609:Barium Compounds / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry; D003198:Computer Simulation; D060526:Magnetic Fields; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008956:Models, Chemical; D009038:Motion; D010103:Oxygen Isotopes; D011522:Protons; D011789:Quantum Theory; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D017609:Barium Compounds; D002712:Chlorides; D010103:Oxygen Isotopes; C000615258:Oxygen-17; D011522:Protons; D014867:Water; C024986:barium chloride