Heterometallic Molecular Clusters Featuring Triple Bonds Between Uranium and Transition Metals

Abstract

Metal–metal multiple bonding is common amongst the d-block transition metals; but intermetallic multiple bonding involving f-block metals, such as uranium, is extremely rare. This is largely due to the difficulties in synthesis and characterization of the relevant compounds. Here, we report a set of heterometallic clusters featuring uranium-metal triple bond s. X-ray diffraction reveals that the uranium-iron (1.9689(13) A) and uranium-cobalt (2.0926(7) A) bond lengths are shorter than the sum of the triple bond covalent radii for corresponding atoms. These complexes represent the first structurally authenticated example of multiple bonding between f-block elements and first-row transition metals. Theoretical studies reveal the high bond orders ( up to 2.93 ) and the significant degree of covalency in these uranium-metal triple bonds. These studies demonstrate that the uranium-metal multiple bonds are no longer an elusive bonding motif, and this opens an avenue to investigation of the potential applications in catalysis and small-molecule activation of heterometallic clusters with actinide-metal multiple bonds .