Structure and magnetism of two new linear trinuclear copper(II) clusters obtained from the tetradentate N 2O 2 ligand bis(2-hydroxybenzyl)-1,3-diaminopropane

Abstract

Reaction of bis(2-hydroxybenzyl)-1,3-diaminopropane (H 2bhbd) with copper(II) perchlorate and copper(II) chloride in methanol, respectively, leads to linear trinuclear clusters, namely [Cu 3(bhbd) 2(CH 3OH) 2(ClO 4) 2] ( 1) and [Cu 3(bhbd) 2Cl 2](CH 3OH) 4 ( 2). These coordination compounds were characterized by X-ray crystallography, UV–Vis, IR and EPR spectroscopy, and magnetic susceptibility measurements. Both complexes have a linear trinuclear array of copper ions bridged by means of phenolato O atoms and separated by a distance of 2.985(4) Å ( 1) and 2.937(4) Å ( 2). Strong antiferromagnetic interactions between these adjacent Cu II ions govern the magnetochemistry of 1 ( J = −303(1) cm −1) and 2 ( J = −482(3) cm −1) resulting in S = 1/2 ground states fully populated below 150 K. A correlation between the interaction parameter J and the angles within the trinuclear clusters is proposed.