含自由基的二维有机功能分子的可控合成与自组装

Highly delocalized stable neutral organic radical systems, which having single electrons for charge carriers as well as magnetic coupling, is a very promising electron spin vector for constructing magnetical, electrical and photonic multifunctional organic materials without metals. One of the future research directions in the field of organic neutral radicals is the extension from diradicals to multiradicals, from low spin to high-spin sytems. This project will focus on the stabilization of the highly delocalized neutral organic radicals, reasonable modification and optimization of the radical active centers. By increasing the conjugation, introducing a protecting group and changing the shape of the edges, the molecular structures were controlled to achieve enhanced π-delocalization and to regulate molecules twisting for adjusting the physical and chemical properties of molecular systems such as magnetic, photophysical, electrochemical, thermal stability and solubility. The spin regulation by light, heat or solvents and spin-polarization by chiral spin system will be investigated. With the help of other non-covalent interactions such as hydrogen bonding, π-π interaction, van der Waals forces, hydrophobic solvent action, highly ordered supramolecular aggregation structures with controllable shapes and high performance will be built. The influence of aggregation structures on the electronic, magnetic and optical properties will be studied by the self-assembly method at supramolecular level.

高度离域的稳定有机中性自由基体系具有既可作电荷载流子又可作磁耦合子的单电子，是非常有希望的电子自旋载体，可构建具有磁、电、光等多重性质的不含金属的有机功能材料。有机中性自由基研究领域未来的发展方向之一就是从双自由基扩展到多自由基，从低自旋到高自旋发展。本项目拟围绕高度离域有机中性自由基的稳定化，合理修饰优化自由基活性中心，通过增加共轭程度，引入保护基团以及改变体系的边缘形状等方式控制分子结构，以达到增加体系的离域程度，调控分子的扭曲程度以调整分子体系的物理化学性质如磁性能、光物理、电化学、溶解性及热稳定性等，掌握外场如光、热、溶剂等对体系的自旋调控以及手性自旋体系对外加电子的自旋极化规律；并辅以其它非共价作用如氢键、π-π相互作用、范德华作用力、疏溶剂作用构筑形貌可控、高度有序、性能优异的超分子聚集态结构；并利用自组装的方法，在超分子水平研究其磁光电化学性质受聚集态结构的影响。

本项目设计合成了系列高度离域的稳定有机分子自由基，调控分子的扭曲程度以调整分子体系的磁光电等物理化学性质，基于非共价作用构筑超分子聚集态结构，利用自组装的方法研究磁光电化学性质受聚集态结构的影响。发展了二维扭曲功能分子体系，制备了扭曲的“X”形分子，实现了对磁性的精准调控；建立了超分子作用导向的自组装模式，实现了超分子聚集态结构和光物理性质的调控；从前体分子构型控制出发，发展了基于石墨炔的二维有机材料的合成方法学，实现了晶态石墨炔的可控制备；发展了结构精确的石墨炔一维纳米带、类三维石墨炔的可控制备方法，实现了石墨炔维度的控制；通过二维分子拓扑结构的改变、表面修饰及功能复合，实现了基于石墨炔的有机自由基体系的调控，拓展了在纳米抗菌剂、催化等领域的应用。发表论文15篇，出版专著1本。