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⁻

Journal Article · Mon Jun 16 04:00:00 EDT 2008 · Inorganic Chemistry, 47(12):5485-5494

DOI:https://doi.org/10.1021/ic800021h· OSTI ID:959168

Dixon, David A; Grant, Daniel J; Christe, Karl O; Peterson, Kirk A

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 Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 959168
• Journal Information: Inorganic Chemistry, 47(12):5485-5494, Journal Name: Inorganic Chemistry, 47(12):5485-5494 Journal Issue: 12 Vol. 47; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ATOMIZATION
BROMINE FLUORIDES
CALCULATION METHODS
CHLORINE FLUORIDES
CORRECTIONS
ELECTRON PAIRS
ELECTRONIC STRUCTURE
Environmental Molecular Sciences Laboratory
FORMATION HEAT
IODINE FLUORIDES
STEREOCHEMISTRY
VIBRATIONAL STATES