Mono and Trinuclear Metal Complexes Containing an N₃O₃- Type Tripodal Ligand

Abstract

Mononuclear and trinuclear nickel(II) and copper(II) complexes containing the N₃O₃-type ligand (H₃L), obtained by condensation of 1,1,1-tris(aminomethyl)ethane and salicylaldehyde (1 : 3), were synthesized. Two mononuclear nickel(II) complex units ([Ni(HL)]) are aggregated due to hydrogen bonding between the phenol group of one unit and the phenolate group of the other to give a dimer with homochirality. The trinuclear nickel(II) complex. [Ni₃L₂] consists of three face-sharing octahedra. Three nickel(II) ions form a linear array. Two terminal nickel(II) ions are coordinated octahedrally by L. The central and two terminal nickel(II) ions are bridged by six phenolate oxygen atoms. In the mononuclear square-planar copper(II) complex, [Cu(HL)], one arm of the tripodal ligand is not coordinated to the metal. On the basis of the absorption spectra of the copper(II) complexes, the coordination geometry around each copper ion of the trinuclear complex is assigned to be square planar and copper ions will be bridged by L.

Key Words:

• tripodal ligand
• trinuclear complex
• homochiral pair
• heterochiral pair