N,N′-双[4-(羧基亚甲氧基)亚苄基]乙二胺的酸离解常数的测定及其与金属离子的沉淀反应

DETERMINATION OF DISSOCIATION CONSTANT OF N,N'-BIS [(4-CARBOXYLMETHYLENOXY) BENZILIDENE] ETHYLENE DIAMINE AND ITS PRECIPITATION REACTION WITH METAL IONS

用PH电位滴定法测定了N,N'-双[4-(羧基亚甲氧基)亚苄基]乙二胺的酸式电离常数,并用假环效应与分子内氢键等说明了电离常数的变化,试剂对硬酸离子Th、Zr、RE、Al、Fe等生成难溶盐,探讨了沉淀的条件和沉淀条件对沉淀组成的影响,探讨了试剂用于分离Th和RE的可能性.

The dissociation constants of N,N'-bis[(4-carboxylbenzili-dene)ethylene diamine were determined by pH potentiometric method.Dueto the formation of intramolecular hydrogen bond,it can be expected thatthe dissociation constants of compounds should be less than those of th-eir mother compounds hydroxyacetic acid and benzoic acid.Their pK_avalues reduced more than 3 orders of megnitudes.The synthetic reagentis a very good precipitant for the hard acid ions,such as Fe, Al, Th,Zr,RE,U.The effects of precipitation were studied.