Self-assembly of cationic palladium complexes by redistribution of pyridine ligands

The reaction of [Pd(OAc)2(py)2] with [Li((OEt2)2.5)][B(C6F5)4] was conducted with intent to generate the cationic palladium complex [Pd(OAc)(py)3][B(C6F5)4], (2, py = pyridine). A single crystal structure of this material, however, reveals a 1-D polymer structure formed by the self-assembly of alternating dicationic ([Pd(py)4]2+) and neutral ([Pd(OAc)2(py)2]) palladium units bridged by acetato linkages to give [Pd(py)4][Pd(OAc)2(py)2][B(C6F5)4]2 (3). These two palladium sites are produced by disproportionation of the pyridine ligands in [Pd(OAc)(py)3][B(C6F5)4]. Proton NMR studies confirm the existence of a solvent dependent equilibrium between [Pd(py)4]2+, [Pd(OAc)2(py)2] and [Pd(OAc)(py)3]+.