树枝状模块化可溶性CMP的设计构筑及其光功能性研究

Conjugated microporous polymer(CMP) are a class of important organic porous materials with combined π-conjugation skeleton and inherent nanopore structure. Nevertheless, the partially rotated single bonds between building units make the π-electronic conjugation not being extended sufficiently, which results in adsorption band of mostly reported CMPs residing in visible light rang rather than near infrared rang. Furthermore, most CMPs are obtained as insoluble solid. This insolubility limits the range of processing choice for some of interesting applications of CMPs. Dendritic molecules possess regular hyper-branched structure. By utilizing the versatility of molecular designing, interesting properties like light emitting and light harvesting could be obtained. Meanwhile, excellent solubility of dendritic molecules endow them good processing performance. The cyclophosphazene-based dendrimic molecules have been intensively studied and explored to construct photoactive dendritic molecules due to that cyclophosphazene possess unique 3D oriented spatial arrangement, Therefore, in this project, we explore to design and construct soluble CMP with novel topological structure of dendrimer-like modules by incorporating cyclophosphazene-based dendritic modules into CMP skeleton. This strategy have good potential to extend π-conjugation of CMP skeleton, and meanwhile, the dendritic modules in CMP skeleton will be used as light-harvesting antenna, then structure-property relationship between topological structure of dendrimer-like modules and photo-functionality could be revealed. The nano-photosensitizer based on dendrimer-like soluble CMP are prepared and studied on their photothermal conversion and photodynamic characteristics upon near-infrared light irradiation.

共轭微孔聚合物（CMP）是一类重要的无定型有机多孔材料，一系列具有多种拓扑结构和功能性的CMP已经被合成出来。但是，由于构筑单元之间单键的旋转性，CMP骨架内π电子共轭结构并未充分延展，从而使其光吸收大多集中于可见光区,在近红外光区的吸收并不明显。此外，大多数合成方法获得的CMP都是不溶固体，不利于加工成型。树枝状分子具有规整的超支化结构，通过分子设计可实现发光和光捕获等特性，同时树枝状分子具有优良的溶解性，赋予其良好的加工成型性能。其中，环磷腈树枝状分子因具有独特的三维延展空间构型，在构筑光活性树枝状分子方面的研究颇多。因此，本项目将环磷腈树枝状模块引入CMP骨架中，设计构筑具有新型拓扑结构的树枝状模块化可溶性CMP，延展骨架共轭结构的同时，以树枝状模块作为光捕获天线，探讨新型拓扑结构和光功能性的构-效关系，同时制备基于树枝状模块化CMP的纳米粒子光敏剂，研究光热转换/光动力学特性。

在本项目的资助下，围绕树枝状模块化CMP的构筑和功能化展开，合成了基于环三磷腈树枝状模块的酞菁CMP，并在研究中发现J型聚集显著促进了其光能转换性能；此外，新增加了P=N键连接CMP，以及P-NH键连接共价有机框架（COF）两部分内容，并分别探索了两者在光催化和全固态电解质中的应用。主要内容包括以下三个方面：（1）合成了基于环三磷腈树枝状模块的J型聚集酞菁CMP，分子模拟和对照实验证明，环三磷腈环外相邻酞菁单元间形成明显J型聚集，有效增强了近红外区域的光吸收性能。同时，通过结合聚乙烯基吡咯烷酮，可以制备粒径均一的胶体纳米粒子，在近红外激光下，同时产生优异的光动力学和光热效应。细胞毒性实验证明，在低剂量条件下呈现出高效的癌细胞抑制效果；（2）开展了溶剂热法合成P=N键连接CMP的工作。在高温低压的封管条件下，首次合成出P=N键连接的CMP，类似于C=C键连接全共轭的结构，赋予合适的光吸收范围，使其具有光催化有机合成反应的应用潜力；（3）通过优化溶剂热条件，首次合成出由P-NH键连接的磷腈类结晶型共价有机框架材料（COF），通过粉末XRD和结构模拟，证明了二维COF之间为AB堆积形式，该方法同时适用于多种氨基单体。在此基础上，利用磷腈类COF中环三磷腈环易于季铵盐化的特点，合成了阳离子骨架的磷腈类COF，作为全固态电解质对钠离子具有优异的传导性能。材料骨架中环三磷腈和三嗪单元具有优良的阻燃性能，能进一步提升全固态钠电池的安全性。