title: Microsolvation of LiBO2 in water: anion photoelectron spectroscopy and ab initio calculations.
abstract: The microsolvation of LiBO2 in water was investigated by conducting anion photoelectron spectroscopy and ab initio studies on the LiBO2(H2O)n(-) (n = 0-5) clusters. By comparing calculations with experiments, the structures of these clusters and their corresponding neutrals were assigned, and their structural evolutions were revealed. During the anionic structural evolution with n increasing to 5, hydroxyborate and metaborate channels were identified and the metaborate channel is more favorable. For the hydroxyborate structures, the anionic Li(+)-BO2(-) ion pair reacts with a water molecule to produce the LiBO(OH)2(-) moiety and three water molecules tend to dissolve this moiety. In the metaborate channel, two types of solvent-separated ion pair (SSIP) geometries were determined as the ring-type and linear-type. The transition from the contact ion pair (CIP) to the ring-type of SSIP starts at n = 3, while that to the linear-type of SSIP occurs at n = 4. In neutral LiBO2(H2O)n clusters, the first water molecule prefers to react with the Li(+)-BO2(-) ion pair to generate the LiBO(OH)2 moiety, analogous to the bulk crystal phase of α-LiBO2 with two O atoms substituted by two OH groups. The Li-O distance in the LiBO(OH)2 moiety increases with the increasing number of water molecules and elongates abruptly at n = 4. Our studies provide new insight into the initial dissolution of LiBO2 salt in water at the molecular level and may be correlated to the bulk state.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. zhengwj@iccas.ac.cn fenggang@iccas.ac.cn.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zeng
authors.forename: Gao-Lei
authors.initials: GL
authors.lastname: Hou
authors.forename: Jian
authors.initials: J
authors.lastname: Song
authors.forename: Gang
authors.initials: G
authors.lastname: Feng
authors.forename: Hong-Guang
authors.initials: HG
authors.lastname: Xu
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Zheng
mesh_terms: D000838:Anions / Q000737:chemistry*; D001881:Borates / Q000737:chemistry*; D006860:Hydrogen Bonding; D018020:Lithium Compounds / Q000737:chemistry*; D008958:Models, Molecular; D056951:Photoelectron Spectroscopy / Q000379:methods*; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry*; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D000838:Anions; D001881:Borates; D018020:Lithium Compounds; D012997:Solvents; D014867:Water; C021051:lithium borate