Synthesis Of Several Novel Open Chain Crown Ether Compounds And Their Selective Complexation With Ions

Open chain crown ether belongs to flexible ligand, not only having flexible chain structure but also having rigid end groups which makes it feature excellent binding ability with ions. Because of the varity of the end groups, it can form steady complex with metal ions, like some large ring crown ether. And when changing the end group, it can also form steady complex with anions or cations and recognize them at the same time. To further reveal the selectivity of the open chain crown ether with anions or cations, several novel open chain crown ether are synthesized, and their ion recogenition abilities are investigated by means of UV-vis spectroscopy. The major contents of the thesis are as following:The general aspect of supramolecular chemistry is described briefly. The ion recognition and molecular recognition progress based on crown ether are reviewed.Three novel open chain crown ether (host compoundâ…¡-1,â…¡-2 andâ…¡-3) with end group bis(indolyl)methane are synthesized and characterized by IR, 1H NMR and elemental analysis. Their complexation behaviors with F-,Cl-,Br-,I-,HSO4- are investigated. It is found that the complexation ofâ…¡-1 andâ…¡-2 with F- are significantly differrent with other anions. Furtherly, their Complex Stability Contant and Gibbs free energy changes with F- are studied by UV-vis spectroscopy. The results indicate that host compoundâ…¡-1 andâ…¡-2 give better complex ability and selectivity to F-.thanâ…¡-3.A kind of novel open chain crown ether which bears the chain of 1,10-phenanthroline monohydrate is synthesized and characterized. Complexation behavior with alkali and alkali-earth metal ions (Li+,Na+,K+,Rb+,Cs+,Ca2+,Ba2+)are studied, but no special complexation are found with the above cations.