Decreased overall basicity of a series of new N,N'-bis(carboxymethyl) macrocyclic ether-bis(lactone) ligands derived from EDTA and the ring size effect on the stability constants of their lanthanide complexes

Abstract

In order to examine the effects of positions of the nitrogen donor atoms and the relative coordination sites of the two carboxylate groups on lanthanide complexation in the study of the characteristics of both open-chain and macrocyclic ligands for the preparation of novel metal-ion selective reagents, a series of N, N'-bis(carboxymethyl)macrocyclic ether-bis(lactone)ligands derived from ethylenediaminetetraacetic acid have been prepared and characterized. The ligand protonation constants and the lanthanide complex formation constants have been determined and are reported here. 14 references, 2 figures, 2 tables.