Abstract BrF can be prepared by reaction of Br 2 and F 2 in various solvents below–100 C. In solution it is identified by 19 F NMR and Raman spectroscopy. From CH 3 Cl solution a single crystal structure determination of a BrF/CH 3 Cl adduct was obtained. The preparation from BrF 3 and Br 2 at 600 C also delivers BrF in small amounts. The crystal structure of BrCl comes in an ordered and a disordered variety. The ordered structure is made of Br–Cl··· Br ...