title: Hydration of potassium iodide dimer studied by photoelectron spectroscopy and ab initio calculations.
abstract: We measured the photoelectron spectra of (KI)2-(H2O)n(n = 0-3) and conducted ab initio calculations on (KI)2-(H2O)nanions and their corresponding neutrals up to n = 6. Two types of spectral features are observed in the experimental spectra of (KI)2-(H2O) and (KI)2-(H2O)2, indicating that two types of isomers coexist, in which the high EBE feature corresponds to the hydrated chain-like (KI)2-while the low EBE feature corresponds to the hydrated pyramidal (KI)2-. In (KI)2-(H2O)3, the (KI)2-unit prefers a pyramidal configuration, and one of the K-I distances is elongated significantly, thus a K atom is firstly separated out from the (KI)2-unit. As for the neutrals, the bare (KI)2has a rhombus structure, and the structures of (KI)2(H2O)nare evolved from the rhombus (KI)2unit by the addition of H2O. When the number of water molecules reaches 4, the K-I distances have significant increment and one of the I atoms prefers to leave the (KI)2unit. The comparison of (KI)2(H2O)nand (NaI)2(H2O)nindicates that it is slightly more difficult to pry apart (KI)2than (NaI)2via hydration, which is in agreement with the lower solubility of KI compared to that of NaI.
authors.affiliation: Institute for Chemical Physics, School of Science, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Ren-Zhong
authors.initials: RZ
authors.lastname: Li
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.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zeng
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.
authors.forename: Gao-Lei
authors.initials: GL
authors.lastname: Hou
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.
authors.forename: Hong-Guang
authors.initials: HG
authors.lastname: Xu
authors.affiliation: Institute for Chemical Physics, School of Science, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Yi Qin
authors.initials: YQ
authors.lastname: Gao
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.
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Zheng