Synthesis, Electronic Structure, and Reactivity of Palladium(I) Dimers with Bridging Allyl, Cyclopentadienyl, and Indenyl Ligands

Abstract

The synthesis of three new Pd(I) dimers, (μ-All)(μ-Cp){Pd(PEt3)}2 (All = C3H5, Cp = C5H5), (μ-All)(μ-Ind){Pd(PEt3)}2 (Ind = C7H9), and (μ-Cp)(μ-Ind){Pd(PEt3)}2, which contain a combination of bridging allyl, Cp, or indenyl ligands and are all supported by triethylphosphine as the ancillary ligand, is reported. The solid-state geometries, electronic structures, and reactivity of these new compounds have been compared with those of the dimers (μ-All)2{Pd(PEt3)}2 and (μ-Cp)2{Pd(PEt3)}2, which have previously been reported. This work establishes that there are many similarities in the solid-state and electronic structures of complexes containing bridging allyl, Cp, or indenyl ligands. For example, in all cases the bridging ligands bind through three carbon atoms to the two Pd atoms, with only the central carbon atom of the bridging group bound to both metal centers. However, there are also important differences based on the identity of the bridging ligand. As a result of different overlap between the metal ce...