Facile syntheses of pure uranium halides: UCl₄, UBr₄ and UI₄

Herein we describe convenient lab scale syntheses of several uranium(iv) halides of high purity by reaction of AlX₃ (X = Cl, Br and I) with UO₂, which is readily available by reduction of uranyl salts like UO₂(NO₃)₂·6H₂O. UCl₄, UBr₄, and UI₄ are obtained in the form of aggregates of large single crystals. Their identities and purity were checked by powder X-ray diffraction, IR spectroscopy and elemental analysis. The syntheses introduced here avoid the need for pure metallic uranium and are based on more readily available starting materials, UO₂, which does not even have to be pure, and the respective aluminium halide. Chemical vapor transport (CVT) is applied in situ for purification of the products.