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 (Cd4L4)-L-II tetrahedra, one with ligands puckered inward, and the other outward. The third product was a (Cd8L8)-L-II 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.