Reversible Concerted Ligand Substitution at Alternating Metal Sites in an Extended Solid

We report a synthetic material, [Co₂(bipy)₃(SO₄)₂(H₂O)₂](bipy) (CH₃OH), (1, where bipy = 4,4'-bipyridyl) that contains discrete reactive and inert structural motifs that undergo a reversible substitution reaction involving the concerted and spatially controlled introduction of bipyridine and methanol molecules at the reactive sites. This reaction defines the pore geometry of the resulting open-framework structure and controls the manner in which this structure sorbs small molecules. The molecules involved in the reaction are positioned by an array of well-defined interactions during their path to binding to the metal centers.