基于刚性分子碗“杂化素馨烯”的曲面共轭分子设计合成及其组装材料的性能研究

Organic functional materials, the basis to fabricate next-generation electronic devices, are built up through the assembly of organic molecules. Therefore, the key gateway to develop organic functional materials is the exploration of organic functional molecules having unique features on both electronic and assembly aspects. In the present proposal, we aim at the design and synthesis of curved conjugated molecules with unique geometry and optoelectronic properties. The research will be performed in the squence of highly efficient synthesis of functional molecules, structure-property relationship and function-directed derivation of the resulting molecules, and molecular assembly and the properties of supramolecular materials. Taking advantage of our breakthrough progress on the facile synthesis of hetera buckybowl trichalcogenasumanenes, we will conduct the following research to gain the original innovations on conjugated molecules with curvatures: (1) exchanging the hetero atoms on heterasumanene to finely modulate the molecular geometries, packing motifs, and the electronic states of heterasumanenes; (2) exploring spoon-like conjugated molecules, as well as tailoring the handle of spoon to adjust the electronic states and assembling nature of molecular spoons; (3) fusing the optoelectonically active units such as tetrathiafulvalene and fullerenes onto heterasumanene to achieve mutiple functionalities; (4) chemical engineering on the side-chain of heterasumanenes to regulate the self-assemble nature, and their supramolecular assemble with guest molecules. The intrinsic optoelectronic properties, assembly nature, and structure-property relationship of the curved molecules will be evaluated by means of single crystal structure analysis, dynamic light scattering, time-resolved spectroscopy, spectroelectrochemistry, and so on. Futher investigation is directed to the controllabe supramolecular assembly to gain the condensed matters, and the fabrication of OFET and OPV based on the supramolecular materials.

有机功能材料由有机分子组装而成，是新一代功能器件的物质基础。功能导向的有机分子的设计合成及可控组装是有机功能材料的基础和创新点。本项目以结构新颖性能独特的曲面共轭分子为研究对象，沿着“分子设计合成、构效关系和可控功能化、分子组装及材料性能”来铺展研究内容。基于本课题组在“硫杂素馨烯”分子碗的高效合成方面的前期研究基础，本项目拟通过置换共轭体系中的杂原子来调控素馨烯类分子碗的构型、堆积及电子结构，发展勺状分子的高效合成并通过裁剪勺柄长度来调控其电子结构和组装方式，实现杂化素馨烯与四硫富瓦烯/富勒烯等光电活性单元的共价键融合；采用侧链工程来调控分子碗和勺状分子的自组装及其与富勒烯/原子簇的主客体超分子组装；利用晶体衍射、瞬态光谱、光谱电化学、动态光散射等手段来研究曲面分子的本征光电性能、构效关系、组装特征；通过可控组装来制备长程有序的微纳材料并探索它们在场效应传感器和光伏电池中的应用。

曲面共轭分子具有独特的电子结构和性能。该领域的关键科学问题和技术难题分别为：如何调控曲面共轭分子性能、如何高效且宏量合成曲面共轭分子。我们以创制新型曲面共轭分子为核心，然后进行构效关系分析、可控功能化、分子组装及光电性能研究，完成了既定目标。① 基于共轭体系掺杂以调控结构与性能的思路，设计合成了12种含有S, Se, Te, N, P等元素的杂化素馨烯；基于位阻诱导π-平面形变的策略，设计合成了3种扭曲的石墨烯纳米带；基于杂化素馨烯与功能单元相融合的思路，设计合成了以“分子水车”为代表的6种新型曲面共轭分子。② 运用物理有机化学方法，解析了主族元素与杂化素馨烯的结构和功能之间的相关性、分子内部功能单元之间的电子/能量传递机制；发现了杂化素馨烯的新反应—酸诱导的分子间原子转移反应、tellura-Bayer-Villiger反应等，并以这些化学反应为基础，实现了手性稠环等新体系的高效合成。③ 瞄准曲面共轭分子空间构型、电子结构、辅助基团等结构特征，实现了其与富勒烯的超分子组装及富勒烯分离，与金属离子的配位组装及Ag+选择性检测，飞秒时间尺度的光谱响应及单线态氧、有毒物质（比如S2-/SH-、苯胺）检测。这些研究进展为创制新型曲面共轭分子提供了新思路和新方法、为曲面共轭分子的功能应用提供了理论基础和关键物质。截止项目结题，我们在Angew. Chem. Int. Ed., Chem. Sci., Chem. Eur. J.等期刊发表论文17篇。参与项目的研究生，6人获博士学位、1人获硕士学位。项目负责人于2017年担任国家重点研发计划纳米科技专项项目课题组长、于2021年获得国家自然基金面上项目资助。