Neutron Scattering Studies of the Hydration Structure of Li+

0443385 - ÚOCHB 2016 RIV US eng J - Journal Article
Mason, Philip E. - Ansell, S. - Neilson, G. W. - Rempe, S. B.
Neutron Scattering Studies of the Hydration Structure of Li+.
Journal of Physical Chemistry B. Roč. 119, č. 5 (2015), s. 2003-2009. ISSN 1520-6106. E-ISSN 1520-5207
Institutional support: RVO:61388963
Keywords : initio molecular dynamics * concentrated aqueous solution * quasi-chemical theory
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 3.187, year: 2015

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+, similar to 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) angstrom and 2.58 (0.02) angstrom, 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.
Permanent Link: http://hdl.handle.net/11104/0246122