新型大环聚醚的合成及配位性能

本文报道一类新型大环聚醚的合成.在以1,7-二氧杂-4,10-二氮杂环十二烷(1a)及1,7,10,16-四氧杂-4,13-二氮杂环十八烷(1b)中的两个仲胺上进行含醚键的卤代烷取代反应,获得一批带有两个含有侧链醚键的新型冠醚.以碳酸钾为缩合剂,所得冠醚碱金属配合物经酸分解及四甲基氢氧化铵处理后,得游离的大环聚醚. 用溶解度法初步测定了这类冠醚对碱金属的配位性能.结果指出,其母环及侧链上氧原子数的多少及碱金属离子半径的大小均影响配合物的稳定性,其中有些冠醚对碱金属有良好的配位能力,有的还具有优异的选择性,例如N,N′-β-甲氧基乙基-1,7-二氧杂-4,10-二氮杂环十二烷(13a)对钾及钠离子的选择比大于18-c-β,并比4,4′(5′)-二甲基苯并-30-c-10还高.

The synthesis and coordination properties of new macrocyclic polyethers

A new type of macrocyclic polyethers has been synthesized. It consists of a monocyclic polyether ring and two side chains. The monocyclic polyether is composed of two bridge head nitrogen atoms and two hydrocarbon bridges, each bridge is separated into intervals by oxygen atoms. The side chain is made of ethyleneoxy polyether with alkyl group as end group. The size of monocyclic polyether and side chain may be varied as desired. The general formula is shown as 2 in the Chinese Text. The synthetic route of the compounds was described (see Formula (1-6). in the Chinese Text). In order to obtain pure products, the reaction mixture, after the solvent has been distilled off, is treated with hydrochloric acid. Metal salt is precipitated and removed by centrifugation. The mother liquor is neutralized with tetramethylammonium hydroxide. The desired macrocyclic polyether is extracted into organic solvent and purified after the removal of solvent by vacuum distillation. The ability of complexing alkali cations of macrocyclic polyethers has been studied by the method of solubilities of salts in chloroform. Their equilibrium constants are estimated. It is shown that they possess high ability to complex alkali cations. Some of them also possess high selectivity for Na+ and K+ ions The new macrocyclic polyethers possess following characteristics: (1) The method of synthesis and purification is simple and facile, the yields are good (30-65%). (2) When a suitable size of monocyclic polyethers and side chains are chosen, the macrocyclic polyether will possess both good complexing ability and good selectivity. (3) With the number of carbon atoms in the end alkyl group increasing, the solubility of macrocyclic polyethers in organic phase can be substantially improved.