Nickel-Triad Complexes of a Side-on Coordinating Distannene

NHC adducts of the stannylene Trip(2)Sn (Trip=2,4,6-triisopropylphenyl) were reacted with zero-valent Ni, Pd, and Pt precursor complexes to cleanly yield the respective metal complexes featuring a three-membered ring moiety Sn-Sn-M along with carbene transfer onto the metal and complete substitution of the starting ligands. Thus the easily accessible NHC adducts to stannylenes are shown to be valuable precursors for transition-metal complexes with an unexpected Sn-Sn bond. The complexes have been studied by X-ray diffraction and NMR spectroscopy as well as DFT calculations. The compounds featuring the structural motif of a distannametallacycle comprised of a [(NHC)(2)M-0] fragment and Sn(2)Trip(4) represent rare higher congeners of the well-known olefin complexes. DFT calculations indicate the presence of a p-type Sn-Sn interaction in these first examples for acyclic distannenes symmetrically coordinating to a zero-valent transition metal.