Synthesis and crystal structure of tri-ethyl-ammonium hexa-bromido-uranate(IV) di-chloro-methane monosolvate.

Tri-ethyl-ammonium hexa-bromido-uranate(IV) di-chloro-methane monosolvate, [(C2H5)3NH]2[UBr6]·CH2Cl2, was obtained in the form of dark-brown crystals from the reaction of uranium penta-bromide with NEt3 and ethyl-ene glycol in di-chloro-methane at low temperature. During the progress of the reaction, the reduction of uranium(V) to uranium(IV) was observed, whose associated oxidation product could not be identified. The uranium atom of the [UBr6]2- anion is coordinated by six bromido ligands in the shape of an octa-hedron. Between cations, anion and solvent mol-ecules of crystallization, numerous C-H⋯Hal hydrogen-bond-like inter-actions are present, leading to a three-dimensional network structure.