A systematic study of halogenate(I/III) anions with polyatomic ligands is presented. The bis(perfluoro-tert-butoxy) halogenates(I) [X(OC4F9)2]−, X=Cl, Br, I, of chlorine, bromine, and iodine are prepared as their tetraethylammonium salts and characterized with IR, Raman, and NMR spectroscopic methods, as well as single-crystal X-ray diffraction analyses. Spectroscopical data are supported by quantum-chemical calculations. Additionally, the bonding situation of the species in question are analyzed and discussed. Furthermore, the oxidation to the corresponding halogenate(III) derivatives was studied. For [Br(OC4F9)2]−, oxidation with elemental fluorine gave [BrF2(OC4F9)2]−. Iodide was directly oxidized by ClOC4F9 to the IIII species [I(OC4F9)4]−, which is a surprisingly inert anion that might be used as a weakly coordinating anion (WCA) in the future. For [Cl(OC4F9)2]−, the decomposition products of the synthetic approaches towards a chlorine(III) system were analyzed.
