双冠醚研究(Ⅳ)——Schiff碱型和仲胺型双-(苯并15冠-5)对碱金属苦味酸盐的萃取行为  

Studies on Bis-Crown Ether(Ⅳ)——Extraction of Alkali Metal Picrates with Schiff-base and Secondary Amine Type Bis-Crown Ethers Containing Benzo 15-Crown-5 Moiety

作　　者：王德枌[1] 王登进[1] 都恒华 孙小强[1] 胡宏纹[1] Wang Defen;Wang Dengjin;Du Henghua;Sun Xiaoqiang;Hu Hongwen(Department of Chemistry,Nanjing University,Nanjing)

机构地区：[1]南京大学化学系

出　　处：《高等学校化学学报》1988年第4期317-322,共6页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金。

摘　　要：仲胺型双冠醚与四苯硼酸碱金属盐在丙酮溶液中。25℃下的电导说明它们与Na^(+)可能形成1:1络合物(冠醚单元:金属离子),而与K^(+)、Rb^(+)、Cs^(+)离子则形成2:1络合物。用Schlff碱型和仲胺型双-(苯并15-冠-5)在水-氯仿体系中进行萃取,测量了分配比D和萃取平衡常数K_(7),发现后者的K_(7)值均大于前者。双冠醚F_(a)对K^(+)的萃取能力最强,选择性最佳。Extraction of alkali metal picrates with Schiff base and secondary amine type bis-crown ethers containing benzo l5-crown-5 moiety was carried out in the medium of chloroform as water immiscible solvent.The compositions of the complexes were determined indirectly by measuring the conductance of acetone solutions of alkali metal tetraphenyl borate-crown ether.It showed that these bis-crown ethers probably formed 2:1 complexes with K^(+),Rb^(+),Cs^(+).The distribution ratio,extraction equilibrium constants Ke were also measured.The Ke dataindicated that for the same alkali metal picrate,the Schiff-base type bis-crown ethers give smaller values than the secondary amines.The secondary amine typebis-crown ether F_(2) exhibited the greatest effectiveness of extraction and selectivityfor potassium ions.

关 键 词：Schiff碱型双冠醚 仲胺型双冠醚 萃取平衡常数 电导法 

分 类 号：O65[理学—分析化学]