Preparation and properties of a triply bridged antiferromagnetically coupled binuclear copper(II) complex [Cu2L(OAc)(2)]ClO4 {L=2,6-bis[(N-methyl piperazin-1-yl) methyl]-4-bromo phenol}

The preparation of a pentadentate binucleating ligand 2,6-bis[(N-methyl pip erazin-1-yl) methyl]-4-bromo phenol (HL) is described together with the cor responding acetato bridged Cu(II) complex [Cu2L(CH3COO)(2)]ClO4. H2O. Both the ligand and complex were characterized by elemental analysis and spectra l studies. The electrochemical behaviour of the complex is discussed in det ail. The structure analysis shows that the ligand is pentadentate donating two nitrogens as well as a bridging oxygen to each copper. Two acetates bri dge the coppers through basal and apical positions to yield square-pyramida l coppers with a distorted square base, perchlorates occupy interstitial po sitions. The structure is held in three-dimensional space by electrostatic attractions and Van der Waal's forces. The variable temperature magnetic st udies reveal weak antiferromagnetic interaction between the two metal cente rs. (C) 1999 Elsevier Science Ltd. All rights reserved.