Oxyfluoro Compounds of Bromine

Abstract

<p>A number of new oxyfluoro compounds of Br (V) have been prepared and isolated; their structures and some of their reactions have been investigated by ¹⁹F nmr and Raman spectroscopy. The previously reported oxyfluoride BrO₂F has been characterized for the first time, and the preparation and characterization of the previously unknown BrOF₃ is described. Reaction of these oxyfluorides with the Lewis acids BF₃ and AsF₅ has been shown to produce the new cations BrO₂⁺ and BrOF₂⁺. The anions BrO₂F₂⁻ and BrOF₄⁻ have also been prepared for the first time by several methods. These new cations and anions have been characterized by Raman and ¹⁹F nmr spectroscopy. Similar results have been simultaneously reported by other groups, working independently.</p> <p>Two selenium (IV) anions SeO₂F⁻ and SeO₂F₂²⁻, which are isoelectronic with BrO₂F and BrO₂F₂⁻, respectively, have been investigated. The Raman spectrum of the SeO₂F⁻ anion has been reassigned and evidence for the formation of the SeO₂F₂⁻ anion is presented for the first time.</p> <p>The ¹⁹F nmr spectrum of the bromine (VII) oxyfluoride BrO₃F has been recorded and interpreted. The Raman spectra of solid and liquid BrO₃F have been obtained and used to support the previously reported assignments of the fundamental bending modes of this molecule. A number of reactions involving the bromine (VII) species BrF₆⁺, BrO₄⁻ and BrO₃F are described. These reactions were carried out in an unsuccessful attempt to prepare the unknown oxyfluorides BrO₂F₃ and BrOF₅.</p>