[UCl 4 (HCN) 4 ] - a hydrogen cyanide complex of uranium tetrachloride.

The reaction of uranium tetrachloride with anhydrous liquid hydrogen cyanide yields a turquoise microcrystalline powder of tetrachloridotetraformonitrileuranium(iv), [UCl4 (HCN)4 ]. We determined the crystal structure of this compound by powder neutron diffraction. The compound was further characterized by IR spectroscopy and thermogravimetric analysis as well as by magnetic measurements. The paramagnetic compound crystallizes in the tetragonal space group type I4[combining macron]. To the best of our knowledge this compound represents the first structurally elucidated uranium(iv) complex with HCN as a ligand.