论文部分内容阅读
含中心功能基的冠醚化合物及其对金属离子的络合行为,已有较多的报导。Cram等报导,在含芳环的冠醚中,苯环的1,3位有二个亚甲基单元占据时,处于2位上的甲氧基、羟基、硝基、卤素等带孤对电子的中心功能基,可以用来调节冠醚环的空腔大小,致使其对金属离子的络合选择性有所改变。由于氧杂冠醚对碱金属和碱土金属离子具有较好的络合作用,而对过渡金属和重金属离子等的络合行为则不甚满意。因此,以氮、硫等杂原子代替冠醚环中的氧原子时,会对过渡金属和重金属离子产生明显的络合效果。
Crown ether compounds containing central functional groups and complexation of metal ions have been reported. Cram et al. Reported that in aromatic ring-containing crown ethers, when there are two methylene units in the 1,3 position of the benzene ring, the methoxy group, the hydroxyl group, the nitro group, and the halogen in the position 2 are lone-pair electrons The central functional group, which can be used to adjust the cavity size of the crown ether ring, causes its complex selectivity to metal ions. Oxyheptyl ether has good complexation with alkali metal and alkaline earth metal ions, while the complex behavior of transition metal and heavy metal ions is not satisfied. Therefore, nitrogen, sulfur and other heteroatoms in place of the crown ether ring oxygen atoms, the transition metal and heavy metal ions have a significant complex effect.