MACROCYCLIC DILACTAMS WITH PENDANT ACIDIC FUNCTIONS AS DISCRIMINATING AGENTS FOR LANTHANIDE IONS

摘要

N,N'-bis(carboxymethyl) macrocyclic dilactams were synthesized in good to high yields from diamines and dianhydrides. Their ligand protonation and lanthanide complex stability constants were measured by a potentiometric method in aqueous solution. The lanthanide discriminating power of 12- and 18-membered macrocyclic dilactams derived from EDTA and EGTA measured by their stability constants were compared with other macrocyclic compounds like diaminocrown-ethers and dilactones. In tile dilactam series the Eu3+ complex was found to be the most stable for the ligand derived from o-phenylene diamine and ETGA dianhydride. [References: 23]