Synthesis, Properties, and Applications of Functional Nano-Sized Conjugated Moleculas

为了开发具有独特功能的新型纳米分子，我们重点研究了几种新的高p扩展体系；它们经过精心设计、选择性合成，并应用于各种功能分子基器件，如光伏电池、场效应晶体管、可溶性有机半导体、发光二极管、分子开关、功能染料等。以下是本项目的主要成果：基于含有缩合噻吩的多吡啶的高效光凝聚分子；研制了与酞菁具有相同电子结构的新型多聚吡啶衍生物。它们在固体状态下具有高溶解度和自组织能力。长硫代噻吩在光伏电池中的应用：合成了用碳酸或氰丙酸锚定末端修饰的低硫代噻吩（四聚体、八聚体、十二聚体），并在染料敏化太阳能电池（DSSCs）中作为活性染料进行了测试。在AM1.5太阳模拟器的光照下，采用氰丙酸锚定修饰的十二聚体制备的DSSCs具有良好的光伏转换效率，可达4.0%。用于高性能ofet的自组装、溶液可加工有机半导体我们发现，结合大的、刚性的、平面的n共轭结构和长烷基链可以得到高可溶性和自组装的有机半导体。利用这种方法，可以获得场效应迁移率高达2.7 cm^2/Vs的溶液处理ofet。以低硫代醌分子为基础的功能性染料：二氰亚甲基取代的低硫代醌达到六聚体。根据低聚硫代醌链的长度，低聚物的吸收带通过可见区（dimes和Mimes）从紫外（单体）转移到近红外（四聚体）。有趣的是，五聚体和六聚体在可见光区再次出现吸收带。这些现象通过实验和理论上的合理化加入开壳香料的贡献“寡硫吩”结构，而不是“寡硫醌”结构。少

In order to develop novel nano-sized molecules showing distinguished functionalities, we focused on several new highly p-extended systems; they were carefully designed, selectively synthesized, and applied to various functional molecular-based devices such as photovoltaic cells, field-effect transistors, soluble organic semiconductors, light emitting diodes, molecular switches, functional dyes, and so on. Followings are major achievements in this project.1. Highly efficient light-condensing molecules based on polphyradines possessing condensed thiophenes; the new polphyradine derivatives that have the same electronic structure with phthalocyanines were developed. They have high solubility and capability of self-organization in the solid state.2. Application of long oligothiophenes to photovoltaic cells: oligothiophenes (tetramer, octamer, dodecamer) modified with a carbonic acid or a cyanopropanoic acid anchoring terminal were synthesized and tested as active dyes in the dye-sensitized … More solar cells (DSSCs). The DSSCs using the dodecamer modified with a cyanopropanoic acid anchor gave good photovoltaic conversion efficiency of 4.0% under the illumination of AM1.5 solar simulator.3. Self-assembling, solution prosessible organic semiconductors for high performance OFETs; we found that combination of large, rigid, and planer n-conjugated structures with long alkyl chains can give highly soluble and self-assembling organic semiconductors. With this approach, solution-processed OFETs with field-effect mobility as high as 2.7 cm^2/Vs were achieved.4. Functional dyes based on oligothionoquinoid molecules: dicyanomethylene-substituted oligothionoquinoids were successfully synthesized up to the hexamer. Depending on the length of the oligothionoquinoid chain, the absorption bands of the oligomers shift from UV (monomer) to near IR (tetramer) via visible regime (dimes and Mimes). Interestingly, pentamer and hexamer showed absorption bands in the visible regime again. These phenomena were experimentally and theoretically rationalized by incorporation of open-shell spices which have contribution of the "oligothiophene" structure rather than the "oligothionoquinoid" structure. Less