Electron diffraction analysis for the molecules with degenerate large amplitude motions: Intramolecular dynamics in arsenic pentafluoride

• Published in: Journal of molecular structure Vol. 1132; pp. 139 - 148
• Main Authors: Kochikov, Igor V., Kovtun, Dmitry M., Tarasov, Yury I.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.03.2017
• Subjects: Arsenic pentafluoride; CCSD(T); Electron diffraction; Equilibrium molecular structure; LAM; Molecular structure and dynamics; Pseudorotation; Quantum chemistry; Pseudorotation; Quantum chemistry; Electron diffraction; Molecular structure and dynamics; Equilibrium molecular structure; LAM; Arsenic pentafluoride; CCSD(T)
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2016.09.064

There exists a noticeable disagreement in the difference of axial and equatorial bond lengths in D3h symmetry arsenic and phosphorus pentafluorides between the GED data and high level quantum chemical results. In order to resolve this disagreement, a new structural analysis of the original experiment of (Clippard & Bartell, Inorg. Chem., 9 (1970) 805–811) was undertaken on the basis of modern approach incorporating spectroscopic evidence and quantum chemical information and allowing for intramolecular large-amplitude motion. The results of the analysis prove the internal insufficiency of the experimental material in the description of the accurate positions of the peaks on the radial distribution function. Additional experimental investigation of pentahalide molecules, especially at high temperatures, is of interest. [Display omitted] •There exists a noticeable disagreement in GED and QC structural parameters in AsF5.•A new structural analysis of the experiment of Clippard & Bartell was undertaken.•Modern LAM approach incorporating QC and spectroscopic information was applied.•The results of the analysis prove the internal insufficiency of the experimental data.•Reduction of 2D degenerated dynamics of pseudorotation to 1D problem is described.