Self-Assembly of four Ni₁₆ Molecular Wheels with Capsule and Tubular Supramolecular Architectures

Four new Ni₁₆ molecular wheels with the general formula [L₄Ni₁₆(RCOO)₁₆(H₂O)_x(MeOH)_12-x] (where H₄L=1,4-bis((E)-((2'-hydroxybenzyl)imino)methyl)-2,3-naphthalenediol, and R=H or Me) have been isolated and structurally characterised. Complexes C1-C3 (R=Me) were formed using nickel (II) acetate and presented as polymorphs with the same formulation of charged components. The same wheel-like architecture was observed in C4 (R=H), which was prepared using nickel (II) formate, demonstrating the potential for further versatility of the system. In contrast to similar four-fold symmetric Ni(II) wheel clusters, measurements of the static magnetic properties of C1 indicated the presence of dominant antiferromagnetic interactions and an S=0 ground state.