A new family of N_xO_y pyridine-containing macrocycles:Synthesis and characterization of their Y(lll),Ln(lll),Zn(ll),and Cd(ll)coordination compounds

摘要

Reaction between 2,6-bis(2-formylphenoxymethyl)pyridine and N,N-bis(3-aminopropyl)methylamine or tris(2-aminoethyl)amine has been used as the starting point for the synthesis of seven oxa-aza macrocyclic ligands,five of them never reported previously.They all feature different pendant arms,which provide a wide range of coordination possibilities.The Schiff base macrocycles L~1 and L~4 and their reduced ligands L~2 and L~5 are derived from 2,6-bis(2-formylphenoxymethyl)pyridine and tris(2-aminoethyl)amine or N,N-bis(3-aminopropyl)methylamine,respectively.The reaction of L~1 with salicylaldehyde forms L~3,which features an imine bond in the pendant arm.The ligand L~5 has been the precursor for the pendant-armed L~6 and L~7,by alkylation of the free NH groups with methyl-imidazole or methyl-indole.By a template or a nontemplate approach,we have synthesized different mono- and dinuclear complexes with Y(III),Ln(III),Zn(II),and Cd(II)cations.Both the free macrocyclic ligands and their corresponding metal complexes have been characterized by microanalysis,IR,UV-vis,~]H and ~13C NMR spectroscopy,FAB mass spectrometry,MS electrospray,and conductivity measurements.