Synthesis and characterization of copper(ii) complexes: their catalytic behavior towards alcohol oxidation using NaOCl as the oxidant

Abstract

Two mononuclear complexes, [Cu(L₁)₂] (complex 1) and [Cu(HL₂)₂](NO₃)₂ (complex 2) where HL₁ is 1-((cyclohexylmethylimino)methyl)-naphthalen-2-ol and HL₂ is 4-bromo-2-((2-morpholinoethylimino)methyl)phenol, have been synthesized under mild conditions and characterized by different standard analytical methods. Single crystal X-ray diffraction analysis shows that the copper atoms in both copper(II) complexes are in a square planar geometry. These complexes have been used as catalysts in the oxidation of benzyl alcohol and benzyl alcohol with various substituents in the presence of NaOCl as the terminal oxidant. The results show that complex 1 acts as a better catalyst than the other with the highest yield of 91% in the case of 4-methoxy benzyl alcohol oxidation. The copper complex transfers the oxygen of sodium hypochlorite to the alcohol to produce the aldehyde. The use of NaOCl as an oxidant in alcohol oxidation is rare although it is cheap and nonexplosive.