Synthesis, characterization, structure and properties of copper and palladium complexes incorporating azo-amide ligands

Abstract

The reaction of the multidentate ligand N-(2-(aryldiazenyl)phenyl)picolinamide, HL (3a, 3b and 3c) [HL is ArN = NC6H4NHC(O)Py, where Ar is C6H5 for HL1 (3a), p-MeC6H4 for HL2 (3b) or p-ClC6H4 for HL3 (3c), and Py stands for pyridyl], with Cu(CH3COO)(2)center dot H2O and Na2PdCl4 separately afforded the complexes [(L)(2)Cu] (4a, 4b and 4c) and [(L)PdCl] (5a, 5b and 5c) respectively, where the deprotonated ligand L- binds copper(II) and palladium(II) in a tridentate (N,N,N) fashion. X-ray structures of [(L-3)(2)Cu] (4c) and [(L-1)PdCl] (5a) were determined to confirm the molecular structures. The newly synthesized complex 4a exhibits catalytic activity toward the oxidation of alcohols to the corresponding carbonyl compounds and oxidation of organic thioethers to sulfoxide and sulfone, whereas the complex 5a is an active catalyst for Suzuki and Heck reactions. (C) 2014 Elsevier Ltd. All rights reserved.