Synthesis and characterization of a new macrocyclic Schiff base derived from 2,6-diaminopyridine and 1,10-bis(2-formylphenyl)-1,4,7,10-tetraoxadecane and its Cu(II), Ni(II), Pb(II), Co(III) and La(III) complexes

Abstract

A new macrocyclic ligand, 1,3,5-triaza-2,4:7,8:19,20-tribenzo-9,12,15,18-tetraoxacyclounkosa-1,5-diene (L) was synthesized by reaction of 2,6-diaminopyridine and 1,10-bis(2-formylphenyl)-1,4,7,10-tetraoxadecane. Then, its CuII, NiII, PbII, CoIII and LaIII complexes were synthesized by the template effect by reaction of 2,6-diaminopyridine and 1,10-bis(2-formylphenyl)-1,4,7,10-tetraoxadecane and Cu(NO3)2· 3H2O, Ni(NO3)2· 6H2O, Pb(NO3)2, Co(NO3)2· 6H2O, La(NO3)3·6H2O respectively. The ligand and its metal complexes have been characterized by elemental analysis, IR, 1H and 13C NMR, u.v–vis spectra, magnetic susceptibility, conductivity measurements and mass spectra. All complexes are diamagnetic and the CuII complex is binuclear. The CoIII complex was oxidized to CoIII.