Synthesis and crystal structure of tricyclopentadienyl(cyclooctane-1,5-diyl)-uranium dihydroborate

Cp3UCl reacts with NA(HBBN) (BBB = 9-borabicyclo(3.3.3.)nonane) in THF solution to give CP3U(HBBN), which is the first complex having a (BBNH- ligand attached to a d or f transition metal. The IR spectrum and the X-ray crystal structure show that the boron hydride ligand is coordinated to the uranium through two hydrogen bridges. The geometry around the uranium atom is pseudo-tetrahedral if the ?5-cyclopentadienyl ligand centroids and the boron atom are regarded as vertices.