Chemistry of Stannylene-Based Lewis Pairs: Dynamic Tin Coordination Switching Between Donor and Acceptor Character

The coordination chemistry of cyclic stannylene-based intramolecular Lewis pairs is presented. The PSn adducts were treated with [Ni(COD)(2)] and [Pd(PCy3)(2)] (COD=1,5-cyclooctadiene, PCy3=tricyclohexylphosphine). In the isolated coordination compounds the stannylene moiety acts either as an acceptor or a donor ligand. Examples of a dynamic switch between these two coordination modes of the PSn ligand are illustrated and the structures in the solid state together with heteronuclear NMR spectroscopic findings are discussed. In the case of a Ni-0 complex, Sn-119 Mossbauer spectroscopy of the uncoordinated and coordinated phosphastannirane ligand is presented.