STRUCTURAL STUDIES ON NEW TYPES OF MACROCYCLIC COMPOUNDS I. CRYSTAL STRUCTURE OF NICKEL（II） COMPLEX WITH 5,5,7,12,12,14-HEXAMETHYL- 1,4,8,11-TETRAAZACYCLOTETRADECANE-N,N' -DIACETIC ACID

摘要

＜正＞ Introduction. In recent years, studies on new types of macrocycles featuring ionizable functions have greatly increased since the ligands have an excellent ability to bind certain cations selectively. DOTA （1,4,7,10-tetraaza-cyclododecane-N,N’,N", N’"-tetraacetic acid）, for instance, forms the most stable complexes so far with calcium and trivalent lanthanides 1—5. It is