Structure and magnetism of two new linear trinuclear copper(II) clusters obtained from the tetradentate N2O2 ligand bis(2-hydroxybenzyl)-1,3-diaminopropane
摘要:
Reaction of bis(2-hydroxybenzyl)-1,3-diaminopropane (H(2)bhbd) with copper(II) perchlorate and copper(II) chloride in methanol, respectively, leads to linear trinuclear clusters, namely [Cu-3(bhbd)(2)(CH3OH)(2)(ClO4)(2)] (1) and [Cu-3(bhbd)(2)Cl-2](CH3OH)(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) Angstrom (1) and 2.937(4) Angstrom (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. (C) 2004 Elsevier B.V. All rights reserved.