Facile syntheses of pure uranium halides: UCl 4 , UBr 4 and UI 4 .

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 ·6H2 O. 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.