Synthesis and Spectral Studies of Macrocyclic Pb(II), Zn(II), Cd(II) and La(III) Complexes by Template Reaction of 1,2-Bis(2-formylphenyl)ethane with Metal Nitrate and Various Diamine

Abstract

Eight new macrocyclic complexes were synthesized by template reaction of 1,4-bis(3-aminopropoxy)butane or (+/-)-trans-1,2-diaminocyclohexane with metal nitrate and 1,2-bis(2-formylphenyl)ethane and their structures were proposed on the basis of elemental analysis, FT-IR, UV-Vis, molar conductivity measurements, H-1 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 Cd(II), Pb(II) and Zn(II) complexes and 1 : 3 electrolytes for La(III) as shown by their molar conductivities (Lambda(m)) 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 Cd(II) and Zn(II) complexes were proposed to probably tetrahedral, La(III) complexes are octahedral and Pb(II) complexes are octahedral geometry in the L-1 complex and tetrahedral geometry in the L-2 complex.