Incorporation of a Phosphino(pyridine) Subcomponent Enables the Formation of Cages with Homobimetallic and Heterobimetallic Vertices

[Image: see text] Biological systems employ multimetallic assemblies to achieve a range of functions. Here we demonstrate the preparation of metal–organic cages that contain either homobimetallic or heterobimetallic vertices. These vertices are constructed using 2-formyl-6-diphenylphosphinopyridine, which forms ligands that readily bridge between a pair of metal centers, thus enforcing the formation of bimetallic coordination motifs. Two pseudo-octahedral homometallic M(I)(12)L(4) cages (M(I) = Cu(I) or Ag(I)) were prepared, with a head-to-head configuration of their vertices confirmed by X-ray crystallography and multinuclear NMR for Ag(I). The phosphino-pyridine subcomponent also enabled the formation of a class of octanuclear Cd(II)(4)Cu(I)(4)L(4) tetrahedral cages, representing an initial example of self-assembled cages containing well-defined heterobimetallic vertices.