Synthesis of a novel binucleating symmetrical μ-bis(tetradentate) Schiff base ligand based on pentan-2,4-dione, 2-hydroxybenzaldehyde and 1,4,7,10- tetraazadecane: A new family of dicopper(II/II) complexes

Abstract

The new acyclic binucleating ligand H₃L has been synthesized from a different type of Schiff base condensation reaction of acetyl acetone, salicylaldehyde and triethylenetetramine. The ligand has been characterized by ¹H and ¹³C NMR,

IR and FAB mass spectra. A family of binuclear Cu(II)-Cu(II) complexes of this diimine ligand containing imidazolidine backbone and other supporting exogenous bridges have been synthesized and characterized by elemental analysis, IR, UV-vis, EPR spectral , and magnetic studies. The complexes of general formula [Cu₂(μ-X)(μ-L)].2H₂O (X=OAc, OMe, OEt) are obtained by stoichiometric reaction of the ligand, CuCl₂.4H₂O or Cu(OAc)₂. H₂O and NaX in aqueous-methanol. The ligand reacts with Cu(CH₃CO₂)₂.H₂O in aqueous methanol in air at ambient temperature affording crystalline [Cu₂(μ-OAc) (μ-L

)] .2H₂O in excellent yields. The complexes have two CuN₂O₃ coordination spheres bridged by one exogenous ligand. They represent a new family of imidazolidine bridged dicopper(II/II) complexes in unsymmetrical compartments of a novel μ-bis(tetradentate) liganci (H₃L).