Structure and Heats of Formation of Iodine Fluorides and the Respective Closed-Shell Ions from CCSD(T) Electronic Structure Calculations and Reliable Prediction of the Steric Activity of the Free-Valence Electron Pair in ClF₆⁻, BrF₆⁻, and IF₆⁻
The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. Atomization energies at 0 K and heats of formation at 0 and 298 K are predicted for IF, IF₂-, IF₂+, IF₃, IF₄-, IF₄+,IF₅, IF₆-, IF₆+, IF₇, IF₈-, BrF₆-, and ClF₆- from coupled cluster theory [CCSD(T)] calculations with effective-core potential correlation-consistent basis sets for I. In order to achieve near chemical accuracy (±1 kcal/mol), three corrections were added to the complete basis set binding energies based on frozen-core coupled-cluster theory energies: a correction for core-valence effects, a correction for scalar relativistic effects, and a correction for firstorder atomic spin-orbit effects. Vibrational zero-point energies were computed at the coupled-cluster level of theory except for IF₆-, IF₇, and IF₈-. The calculated heats of formation for the neutral and ionic IFn fluorides were used to predict fluoride affinities. It is shown that high-level calculations are required to predict correctly the steric activity of the free-valence electron pair on the central atoms in IF₆- (C₃v), BrF₆- (Oh), and ClF₆- (Oh). The vibrational spectrum of IF₈- was reanalyzed, and complete mode descriptions for square-antiprismatic XF₈ species of D₄d symmetry are given.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 959168
- Journal Information:
- Inorganic Chemistry, 47(12):5485-5494, Vol. 47, Issue 12; ISSN 0020-1669
- Country of Publication:
- United States
- Language:
- English
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