P. Winklebauer. Chemical Formula = [ Cu { ( P ( CH3 )(C6H5)2) }3 ( BH4) ]

The structure has the unique feature of a hydrogen (from the tetrahydroborate anion) being bonded to copper, i.e., the tetrahydroborate anion is attached to copper through a hydrogen bridge bond. The Cu to bonded-hydrogen distance is 1.47 Angstroms. The overall structure is approximately tetrahedral, but P - Cu - P bond angles are larger than expected due to steric repulsion of the phenyl groups.