Lutetium(III) oxide bromide, LuOBr

Single crystals of lutetium oxide bromide, LuOBr, were obtained accidentally as a by-product of the reaction of lutetium metal, ruthenium powder and lutetium tribromide, LuBr3, in a sealed tantalum container. As is typical for rare-earth oxide halides of the type REOX (RE = rare-earth metal and X = halogen), LuOBr crystallizes in the tetra­gonal PbFCl structure type (matlockite), where Lu, O and Br are situated on positions with 4mm, \overline{4}m2 and 4mm symmetry, respectively.