Please use this identifier to cite or link to this item:
|Title:||Fluorocations of Krypton, Xenon and Bromine(VII)|
|Authors:||Schrobilgen, John Gary|
|Abstract:||<p>The formation, structures and reactions of a number of noble gas species have been investigated by ¹⁹F nmr and Raman spectroscopy. The XeF₃⁺, XeOF₃⁺ and XeO₂F⁺ cations have been prepared from the corresponding xenon fluoride or oxyfluoride and a strong fluoride acceptor such as SbF₅, and characterized for the first time. Their geometries have been determined largely by the aid of ¹⁹F nmr spectroscopy and shown to be in accord with the predictions of the electron pair repulsion theory. The reactions of Xe₂F₃⁺ and XeF₆ with HSO₃F have been shown to give rise to two new fluorosulfate species, (FXe)₂SO₃F⁺ and F₅XeSO₃F, respectively.</p> <p>The chemistry of krypton difluoride has, until the present work, been very limited. The only known fluoride is KrF₂ and its only reported derivative was KrF⁺ which has, itself, been little studied. A number of new KrF⁺ salts and the previously unknown Kr₂F₃⁺ and Kr₂F₃⁺·xKrF₂ species have been synthesized and studied. The cations of krypton (II) are extremely powerful oxidative fluorinating agents and have been used to prepare the hitherto unknown BrF₆⁺ cation from BrF₅. Attempts to prepare BrF₇ from the BrF₆⁺ cation were not successful. The krypton (II) cations and BrF₆⁺ have been shown to be extremely powerful oxidants, oxidizing O₂ to O₂⁺ and Xe to XeF⁺ under ambient conditions and are probably the most potent oxidants presently known.</p> <p>Although the majority of the noble gas compounds studied in this work can be approximately formulated as NgFᵪ⁺MF₆⁻ or NgFᵪOy₃⁺MF₆⁻, direct vibrational spectroscopic evidence for a weak covalent interaction between the cation and a fluorine on the anion has been obtained in the case of the krypton (II) salts and XeF₃⁺SbF₆⁻. The X-ray crystal structure of XeF₃⁺SbF₆⁻ has also been determined and supports the view that these "fluorine bridge interactions exhibit a substantial degree of covalent character. Consequently, the electron pair repulsion theory, which has proven highly successful in predicting the geometries of isolated molecules has also proven useful in assessing the preferred relative geometries of the fluorine-bridged anion and cation in solid XeF₃⁺SbF₆⁻ and related noble gas compounds.</p>|
|Appears in Collections:||Open Access Dissertations and Theses|
Items in MacSphere are protected by copyright, with all rights reserved, unless otherwise indicated.