Copper(II) complexes with ONS donor ligand and triphenylphosphine: Synthesis, characterization and catalytic applications

A series of Cu(II) complexes of Schiff bases derived from the condensation of o-aminothiophenol with 2-hydroxy-1-naphthaldehyde or salicylaldehyde or its derivatives (Br, Cl, NO2 or CH3) have been reported. The structural features of the complexes have been obtained from their elemental analyses, magnetic susceptibility, IR, electronic and EPR spectral studies. IR spectra suggest that these ligands act as tridentate dibasic donor coordinating through the phenolic oxygen, azomethine nitrogen and thiophenol sulphur atoms. Magnetic moments, electronic spectra and EPR spectra of the complexes suggested a square planar geometry around the Cu(II) ion. The redox behaviour of copper complexes has been studied by cyclic voltammetry. The new Cu(II) complexes have been utilized as catalysts for N-arylation of imidazole.