A new linear double phenoxide-bridged trinuclear Cu(II) Schiff base complex: Synthesis, crystallographic elucidation, magneto-structural correlation and DFT Study

The tetradentate (ONNO) donor Schiff base ligand LH2, derived from the condensation of salicylaldehyde and 1,3-diaminopropane, has been synthesized and reacted with CuBr2 to yield a trinuclear complex with the molecular formula [Cu3L2Br2]. Single crystal X-ray diffraction study reveals that the two terminal copper atoms adopt a square pyramidal geometry, whereas the central copper atom, situated at the inversion centre, is surrounded by four phenoxide oxygen atoms in a square planar fashion. Variable temperature magnetic susceptibility measurement study shows strong antiferromagnetic intra-trimer interactions between the copper centers with a J value of −302 cm−1. EPR study of the complex depicts that, due to the exchange coupling between the copper ions, the EPR spectra were unresolved, having very broad resonances with g = 2.133. A theoretical DFT calculation was also carried out to supplement the experimental results.

A new trinuclear copper complex with a salen type ligand has been synthesized and characterized. Antiferromagnetic interactions between the copper(II) centers are observed for the complex. The EPR spectra remain unresolved with very broad resonances, due to the exchange coupling between the copper ions. A general theoretical DFT calculation was also carried out to support the experimental results.Figure optionsDownload as PowerPoint slide