Shi R, Wang P, Tang L, Huang X, Chen Y, Su Y, Zhao J. Structures and Spectroscopic Properties of F
-(H
2O)
n with n = 1-10 Clusters from a Global Search Based On Density Functional Theory.
J Phys Chem A 2018;
122:3413-3422. [PMID:
29546760 DOI:
10.1021/acs.jpca.7b08872]
[Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Using a genetic algorithm incorporated in density functional theory, we explore the ground state structures of fluoride anion-water clusters F-(H2O) n with n = 1-10. The F-(H2O) n clusters prefer structures in which the F- anion remains at the surface of the structure and coordinates with four water molecules, as the F-(H2O) n clusters have strong F--H2O interactions as well as strong hydrogen bonds between H2O molecules. The strong interaction between the F- anion and adjacent H2O molecule leads to a longer O-H distance in the adjacent molecule than in an individual water molecule. The simulated infrared (IR) spectra of the F-(H2O)1-5 clusters obtained via second-order vibrational perturbation theory (VPT2) and including anharmonic effects reproduce the experimental results quite well. The strong interaction between the F- anion and water molecules results in a large redshift (600-2300 cm-1) of the adjacent O-H stretching mode. Natural bond orbital (NBO) analysis of the lowest-energy structures of the F-(H2O)1-10 clusters illustrates that charge transfer from the lone pair electron orbital of F- to the antibonding orbital of the adjacent O-H is mainly responsible for the strong interaction between the F- anion and water molecules, which leads to distinctly different geometric and vibrational properties compared with neutral water clusters.
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