Cation- and Anion-Exchanges Induce Multiple Distinct Rearrangements within Metallosupramolecular Architectures

Different anionic templates act to give rise to four distinct Cd^II-based architectures: a Cd₂L₃ helicate, a Cd₈L₁₂ distorted cuboid, a Cd₁₀L₁₅ pentagonal prism, and a Cd₁₂L₁₈ hexagonal prism, which respond to both anionic and cationic components. Interconversions between architectures are driven by the addition of anions that bind more strongly within a given product framework. The addition of Fe^II prompted metal exchange and transformation to a Fe₄L₆ tetrahedron or a Fe₁₀L₁₅ pentagonal prism, depending on the anionic templates present. The equilibrium between the Cd₁₂L₁₈ prism and the Cd₂L₃ triple helicate displayed concentration dependence, with higher concentrations favoring the prism. The Cd₁₂L₁₈ structure serves as an intermediate en route to a hexafluoroarsenate-templated Cd₁₀L₁₅ complex, whereby the structural features of the hexagonal prism preorganize the system to form the structurally related pentagonal prism. In addition to the interconversion pathways investigated, we also report the single-crystal X-ray structure of bifluoride encapsulated within a Cd₁₀L₁₅ complex and report solution state data for J-coupling through a CH···F^– hydrogen bond indicating the strength of these interactions in solution.