Anion-Templated Formation of Supramolecular Multinuclear Assemblies

摘要

The use of anions as supramolecular building motifs is reported herein. The interaction of various anions with [ZnACHTUNGTRENUNG(salphen)] complexes (salphen=N,N’-phenylenebis(salicylideneimine)) has been studied, with a particular focus on assembly formation in the presence of acetate anions. Strong association of the latter with the Zn metal centre of the salphen complex was quantified by UV/Vis titration studies. The [ZnACHTUNGTRENUNG(salphen)]–OAc assemblies were further characterized by NMR spectroscopy and X-ray analysis and revealed that the acetate anions can function as bridging modules between two [ZnACHTUNGTRENUNG(salphen)] units. The binding strength of a second complex to the acetate anion may be regulated by the substitution pattern of the salphen ligand. The anion-templated assembly formation was further demonstrated by the supramolecular synthesis of a trinuclear Zn3 assembly. These results hold promise for the directed assembly formation of [ZnACHTUNGTRENUNG(salphen)] complexes with biologically relevant carboxylates, such as amino acids, and potentially new bio-sensing materials.