title: (2) H and (139) La NMR Spectroscopy in Aqueous Solutions at Geochemical Pressures.
abstract: Nuclear spin relaxation rates of (2) H and (139) La in LaCl3 +(2) H2 O and La(ClO4 )3 +(2) H2 O solutions were determined as a function of pressure in order to demonstrate a new NMR probe designed for solution spectroscopy at geochemical pressures. The (2) H longitudinal relaxation rates (T1 ) vary linearly to 1.6 GPa, consistent with previous work at lower pressures. The (139) La T1 values vary both with solution chemistry and pressure, but converge with pressure, suggesting that the combined effects of increased viscosity and enhanced rates of ligand exchange control relaxation. This simple NMR probe design allows experiments on aqueous solutions to pressures corresponding roughly to those at the base of the Earth's continental crust.
authors.affiliation: Department of Chemistry, University of California, Davis, 1 Shields Ave, Davis, CA 95616 (USA).
authors.forename: Gerardo
authors.initials: G
authors.lastname: Ochoa
authors.affiliation: Department of Chemistry, University of California, Davis, 1 Shields Ave, Davis, CA 95616 (USA).
authors.forename: Corey D
authors.initials: CD
authors.lastname: Pilgrim
authors.affiliation: Department of Chemistry, University of California, Davis, 1 Shields Ave, Davis, CA 95616 (USA).
authors.forename: Michele N
authors.initials: MN
authors.lastname: Martin
authors.affiliation: Department of Earth and Planetary Sciences, University of California, Davis (USA).
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Colla
authors.affiliation: Department of Physics, University of California, Davis (USA).
authors.forename: Peter
authors.initials: P
authors.lastname: Klavins
authors.affiliation: Department of Chemistry, University of California, Davis, 1 Shields Ave, Davis, CA 95616 (USA).
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Augustine
authors.affiliation: Department of Chemistry, University of California, Davis, 1 Shields Ave, Davis, CA 95616 (USA). whcasey@ucdavis.edu.|Department of Earth and Planetary Sciences, University of California, Davis (USA). whcasey@ucdavis.edu.
authors.forename: William H
authors.initials: WH
authors.lastname: Casey
keywords: NMR probe design; NMR spectroscopy; aqueous solutions; geochemistry; high pressure