Binuclear copper complexes of bis(1,4,7-triazacyclonon-1-yl) ligands incorporating acetate pendant arms

Abstract

Two new bis(pentadentate) compounds, 1,2-bis[4,7-bis(carboxymethyl)-1,4,7-triazacyclonon-1-yl]ethane (L ¹ ) and 1,4-bis[4,7-bis(carboxymethyl)-1,4,7-triazacyclonon-1-yl]butane (L ² ), have been prepared by functionalisation of the corresponding alkyl-bridged bis(macrocycles) with acetate pendant arms. Their binuclear copper(II) complexes have been prepared and characterised by X-ray crystallography. Both [Cu ₂ L ¹ ]·5H ₂ O and [Cu ₂ L ² ]·2H ₂ O are centrosymmetric about the alkyl bridge with the pentadentate compartments hosting the copper(II) centres oriented away from one another. Each Cu ^II exhibits distorted square-pyramidal geometry with an N ₂ O ₂ basal plane and an apical N atom.