Synthesis of a Flexible Ligand for Assembling Two Metal Ions in Close Proximity. Crystal Structures of Binuclear Nickel and Copper Complexes

Abstract

The new ligand L-OH, containing two diethylenetriamine subunits linked by 2,6-dimethylphenol, forms stable binuclear metal complexes in aqueous solution, in which the coordination environment of the metal ions is unsaturated. The phenolate unit forces the two metal ions to remain close to each other, and the binuclear species then adds a secondary ligand that bridges the two metal centers. This is illustrated by two crystal structures of Cu(II) and Ni(II) binuclear complexes.