title: Neutron scattering studies of the hydration structure of Li+.
abstract: New results derived from the experimental method of neutron diffraction and isotopic substitution (NDIS) are presented for the hydration structure of the lithium cation (Li(+)) in aqueous solutions of lithium chloride in heavy water (D2O) at concentrations of 6, 3, and 1 m and at 1.5 m lithium sulfate. By introducing new and more-accurate data reduction procedures than in our earlier studies (I. Howell and G. W. Neilson, J. Phys: Condens. Matter, 1996, 8, 4455-4463), we find, in the first hydration shell of Li(+), ∼4.3(2) water molecules at 6 m, 4.9(3) at 3 m, 4.8(3) at 1 m in the LiCl solutions, and 5.0(3) water molecules in the case of Li2SO4 solution. The general form of the first hydration shell is similar in all four solutions, with the correlations for Li-O and Li-D sited at 1.96 (0.02) Å and 2.58 (0.02) Å, respectively. The results resemble those presented in 1996, in terms of ion-water distances and local coordination, but the hydration number is significantly lower for the case at 1 m than the 6.5 (1.0) given at that time. Thus, experimental and theoretical results now agree that lithium is hydrated by a small number of water molecules (4-5) in the nearest coordination shell.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Flemingovo nám. 2, 16610 Prague 6, Czech Republic.
authors.forename: P E
authors.initials: PE
authors.lastname: Mason
authors.forename: S
authors.initials: S
authors.lastname: Ansell
authors.forename: G W
authors.initials: GW
authors.lastname: Neilson
authors.forename: S B
authors.initials: SB
authors.lastname: Rempe
mesh_terms: D002412:Cations / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D009010:Monte Carlo Method; D033363:Neutron Diffraction; D053838:Scattering, Small Angle; D014867:Water / Q000737:chemistry
chemical_list: D002412:Cations; D014867:Water; D008094:Lithium