氧化还原型双核茂铁咪唑环蕃类受体分子的合成和氟离子识别研究

The design and synthesis of receptors for highly selective recognition of fluoride anion has become a core topic in the research of fluoride anion recognition. This project will employ imidazole as linker and diferrocenyl and polyoxyethylated crownether chain as constructing unit to construct the diferrocene-based imidazolium cyclophane receptors with double-component redox-active. The four series of novel cyclophane receptors with two imidazolium moieties will be synthesized by the reactions of diferrocenyl imidazole fragment and corresponding dihalide under highly dilute conditions. These receptors have two-component electrochemical response signal, as well as structural features of hydrophilic, lipophilic and multiple binding sites. The recognition properties of these receptors for fluoride anion in aqueous solution will be studied. The enhancement of fluoride anion recognition in aqueous media by receptor containing polyoxyethylated chain and other crown ethers groups will be clarified. The mechanism of the fluoride anion recognition process and concomitant electrochemical response will be explored. The variation of the redox potential of receptors in the recognition process of the fluoride anion will be summarized. The receptor molecule system of fluoride anion with multifunctional identification is expected to be synthesized. The study not only broadens the theoretical basis for fluoride anion recognition, but also has important scientific and practical significance of the development of highly efficient and sensitive detection of fluoride anion.

设计合成高选择性识别氟离子的受体分子是氟离子识别研究中的核心问题。本项目提出利用咪唑桥联双核茂铁基和聚氧乙基链冠醚类基团构建双组分氧化还原型茂铁咪唑鎓环蕃类受体分子的新思路。利用含双核茂铁的二咪唑组分与相应的二卤化物在高稀释条件下关环得到四个系列包含两个咪唑鎓的新型环蕃类受体分子。该类受体不仅具有双组分电化学响应的信号基团，而且具有亲水性、亲脂性和多结合位点的结构特征。研究这些受体分子在含水介质对氟离子的选择性识别性能，阐明聚氧乙基链等冠醚类基团对这些受体在含水介质中识别氟离子的增强作用，探讨氟离子与受体分子间的识别机理以及电化学的响应机制，总结这些受体分子在氟离子识别过程中两组氧化还原电位的变化规律，期待合成具有多功能识别氟离子的受体分子体系。该研究不仅拓宽了氟离子识别的基础研究，而且对发展高选择性高效灵敏的检测氟离子具有重要的科学和实际意义。

本项目原旨在合成氧化还原型双核二茂铁咪唑环蕃类受体分子，并研究其识别氟离子的性质。由于二茂铁咪唑环蕃的合成比较困难，且研究结果表明，开链的二茂铁咪唑盐分子对阴离子识别有着更好的效果，我们在原有基础上加以修改，合成了一系列多臂开链冠状的双核/多核二茂铁咪唑盐/苯并咪唑盐受体、基于双二茂铁丙烷的咪唑/苯并咪唑盐受体分子，并通过电化学测试、核磁滴定、单晶结构分析对其识别阴离子的性能进行了研究。此外，我们一直希望能够利用环蕃的独特空腔结构特点，合成具有生物应用前景的离子识别探针。为此，我们合成了一系列烷氧基桥连的具有荧光性质的咪唑类环蕃受体分子，并通过光谱测试、核磁滴定、单晶结构分析、质谱分析等手段研究其识别离子的性质。研究结果表明，该类分子可以作为有效的离子识别探针。