Subcomponent Flexibility Enables Conversion between D4-Symmetric Cd(II)8L8 and T-Symmetric Cd(II)4L4 Assemblies.

A flexible tris-formylpyridine subcomponent A was observed to produce three distinct products following Cd(II)-templated self-assembly with different anilines. Two of the products were Cd(II)4L4 tetrahedra, one with ligands puckered inward, and the other outward. The third product was a Cd(II)8L8 structure having all mer stereochemistry, contrasting with the fac stereochemistry of the tetrahedra. These three complexes were observed to coexist in solution. The equilibrium between them could be influenced through guest binding and specific interactions between aniline subcomponents, allowing a selected one of the three to predominate under defined conditions.