Design, Synthesis And Anion Recognition Of Ferrocene-based Benzimidazolium Acceptor

Anion plays an extremely important role in chemistry, biology, medicine, environmental science and other related fields. In recent years, a series of receptor molecules such as amide, urea, thiourea, pyrrole and indole have been synthesized and achieved better results in selective recognition of different anions. The interaction between the benzimidazolium salts and anion is based on (C-H)+…X type ionized hydrogen bonds which shows greater intensity than those receptor molecules with neutral recognition sites. Ferrocene has a series of good properties, such as low toxicity, good redox reversibility and ease of modification, etc. Benzimidazole has good biological activity and its structure characteristics could be modified easily. This paper will introduce ferrocene into benzimidazole to design three new benzimidalium acceptors as well as researching the process of selective recognition anions using various techniques including electrochemistry (CV and SWV), UV-vis, and 1H NMR spectroscopy. The main contents are as follows:1. A series of novel ferrocene-based benzimidazolium receptors have been designed and structurally characterized by IR, MS,1H NMR,13C NMR, HRMS and Single Crystal Diffraction.2. The binding properties between receptor and anion have been examined by cyclic voltammetry (CV), differential pulse voltammetry (DPV), NMR titration and UV-vis titration. The electrochemical titration in acetonitrile show electrochemical behavior indicated that all the receptors displayed rather strong electrochemical sensing properties for F- ion in acetonitrile on the condition of host-guest molar ratio 1:8. All of these receptor molecules, receptor 18 has the best result with a remarkable cathodic shift of more than 169 mV. UV-vis titration demonstrated that the receptors 14 and 18 showed affinity and high selectivity for F- anion in acetonitrile. The original absorption peak of the two receptors 14 and 18 on the 270nm,277nm decrease or even disappear. But for new absorption peak generate at 303nm,283nm place.1H NMR titrations demonstrated that the receptor 18 could bind anions through (C-H)+…X- hydrogen bonds forming 1:1 stoichiometric complexes and high selectivity for the F- ion in DMSO-d6 on account of the intensity of the benzim-idazolium C-H resonance decreased gradually and disappeared along with the increase of F- and had a triplet around the 16 ppm region for the FHF".3. Explored the mononuclear benzimidazole salt in catalytic effect on deco-mposition of ammonium perchlorate (AP). DSC-TG demonstrated that the bromine salts presented good catalytic effect on decomposition of ammonium perchlorate (AP). The highest thermal decomposition temperature is up ahead of 92.8℃.4. Monitored these imidazole ionic salt splitting decomposition analysis for multistage mass spectrometry Using (LC-MS). It can help to clarify these comp-ounds and its similar chemical structure.