The colourless compounds Na3OCl and Na3OBr have been prepared and characterized by X-ray diffraction techniques. Na3OCl crystallizes in a cubic primitive lattice with a = 450.0(3) pm (Z = 1). Na3OBr is isotypic with Na3OCl and its lattice constant is a = 457.3(5) pm. The structures are related to the anti-perowskitetype

ChemInform Abstract are obtained as outlined in the scheme (no yields given). The isotypic compounds crystallize in a cubic primitive lattice (Pm3m, Z=1). The structure is related to the anti-perovskite type.