Creation of a Tetranuclear Mn^III₂Mn^II₂ Metalloring Structure Supported by a Penicillamine-Derived Schiff-Base Ligand

The reaction of a Schiff-base ligand derived from 5-chloro-salicylaldehyde and d-penicillamine with MnIII ions in the presence of nBu3N produced a disulfide-bridged tetranuclear MnIII2MnII2 metalloring structure through thiolate oxidation. The corresponding treatment using Et3N instead of nBu3N gave a giant 13-nuclear MnIII6MnII7 structure. A discrete tetranuclear MnIII2MnII2 complex bearing a Schiff-base ligand derived from one of the amino acids, penicillamine, is reported. By changing the kind of amine used as a base, three tetranuclear MnIII2MnII2 complexes were assembled to form a discrete MnIII6MnII7 13-nuclear structure through MnII-O coordination bonds.