We treated CeF4 with HBr as the acidic reaction medium. Tetrabutylammonium bromide served as the source of bromide ligands. Stirring the reaction mixture ratios of 1:1 and 1:2 for lanthanoid and ligand, respectively, in an ice bath resulted in the formation of a bright-orange precipitate. Analysis using UV/Vis spectroscopy revealed the unexpected formation of Br3 - instead of the anticipated CeF4Br -or CeF4Br2 2-. The accumulation of Br3 -appears to outperform the formation of the lanthanoid complex. The possibility of generating bromine radicals from this species is discussed in the Supporting Information.