基于氯化富勒烯的分子探针制备及传感性能研究

Molecular probes have wide applications in fields such as environment and life science for their high sensitivity and use convenience. But their stability and multi-functionalization are to be improved to survive more complex recognition conditions. The way for multi-functionalization of molecular probes by now is mainly through self-assembly approach, which still has instability defect in real application. Fullerene C60 is a carbon-cage like molecule and functional groups are easy to be added on it by multiple addition. As the products are always mixtures of all kind of isomers, their structure analysis and application study are blocked and the multiple functionalization of fullerene moves slowly. Chlorofullerenes are the products of fullerene chlorination and some of them are high-yield compounds, and most importantly they are versatile precursors for fullerene multifunction. Our initial work has synthesized several different chlorofullerenes and preliminary investigation indicates reaction diversity of these molecules owing to their distinct structures. This part of work is still seldom involved. It deserves to be focused on to synthesize more multifunctional fullerenes. Here chlorofullerenes are to be used in fullerene modification with designed spiropyrans and azobenzenes to obtain several kinds of fullerene-based new molecular probes. Their structures are to be confirmed through IR, NMR, HR-MS, UV-Vis and X-ray single crystal diffraction techniques. Conditions such as wavelength, solvent, pH are to be changed to investigate the recognition properties of these probes to find out the best test environment. The recognition differences are to be analyzed among the entire molecule probes with diverse structures and the structure - activity relationships will be figure out to design more excellent molecule probes. We believe it will improve the sensibility of molecular probes and pave the way for fullerene multiple functionalization to realize their application.

分子探针在环境、生物等领域用途广泛，但存在稳定性差、检测单一等问题，通过多功能修饰可望改善不足。目前对其多功能化研究常采用自组装方式使分子探针聚集，未解决稳定和实用性问题。富勒烯C60具有天然笼状结构，能以共价键与多个功能分子加成，但其产物大多分离困难，限制应用研究。氯化富勒烯是少数多加成反应的高选择性产物，且反应性能优异，可实现富勒烯多功能修饰。本课题以发展新型多功能化分子探针、促进富勒烯应用研究为目标，采用具有裸眼识别功能的螺吡喃、偶氮苯为探针主体、几类氯化富勒烯为载体，通过改善探针母体结构及与富勒烯连接方式，设计合成一系列多功能化富勒烯分子探针, 由IR、NMR、HR-MS、UV-Vis等手段表征结构，以比色、荧光、核磁为性能主要检测手段，研究光照、pH、结构等因素对传感及识别性能的影响，通过横纵向比较找出构效规律，为分子探针结构、性能优化及富勒烯应用研究进一步创造条件。

化学传感器分子对分析物进行识别时具有操作简便、易于携带等优点，不过其合成方法及识别过程中的灵敏性、抗干扰性、识别的多样性仍待持续改善，富勒烯的多反应位点为探针识别优势提高提供可能。氯化富勒烯是一类优异的富勒烯衍生化前体，可望将探针分子与富勒烯通过化学键结合，提高探针的传感识别性能。本项目首先以究了含相邻五元环结构的氯化富勒烯#1809C60Cl8的分步修饰反应，通过改变催化剂及底物种类和比例，得到部分取代和全取代的富勒烯衍生物，实现了氯化富勒烯的高效定点分步修饰，随后对氯化富勒烯的电化学行为进行了研究和对比，首次发现含相邻五元环的氯化富勒烯具有电活性不可逆聚合的特点，而常规氯化富勒烯在电化学氧化还原中表现与之不同的出部分可逆特性。在对氯化富勒烯的反应特性掌握的基础上，制备出一系列新型双酰腙小分子探针，证明其对铝离子有高效识别能力及抗干扰能力，检测限可达10-9 mol/L, 比大多数相似类型的探针分子高1-2个数量级，络合常数处于中等水平，达104 M-1，便于实现可逆性识别，对铜离子也有潜在串联识别性能，同时证明探针中邻位羟基存在的必不可少性；制备出2类螺吡喃分子探针，对CN-和F-均据具有裸眼识别功能；对探针与氯化富勒烯之间的化学反应进行了多次尝试，结果表明以探针巯基化后与氯化富勒烯接枝的方式并不太理想，而探针羟基化后与富勒烯反应更加有效，这部分工作将在结题后持续进行。.将科研问题和成果融入本科理论和实验教学，培养了学生科研兴趣和分析解决问题的能力，并有助于学生在第二课堂学以致用，以团队协作的形式参加大学生创新创业大赛和训练项目，加深对所学知识的认知。