Synthesis and spectral studies of macrocyclic Pb(II), Zn(II), Cd(II) and La(III) complexes derived from 1,4-bis(3-aminopropoxy)butane with metal nitrate and salicylaldehyde derivatives

Eight new macrocyclic complexes were synthesized by template reaction of 1,4-bis(3-aminopropoxy)butane with metal nitrate and 1,3-bis(2-formylphenyl)propane or 1,4-bis(2-formylphenyl)butane and their structures were proposed on the basis of elemental analysis, FTIR, UV–vis, molar conductivity measurements, 1H NMR and mass spectra. The metals to ligand molar ratios of the complexes were found to be 1:1. The complexes are 1:2 electrolytes for Pb(II), Zn(II) and Cd(II) complexes and 1:3 electrolytes for La(III) as shown by their molar conductivities (Λm) in DMSO at 10−3 mol L−1. Due to the existence of free ions in these complexes, such complexes are electrically conductive. The configurations of La(III) and Pb(II) were proposed to probably octahedral and Zn(II) and Cd(II) complexes were proposed to probably tetrahedral.