Soroceanu Marius, Constantin Catalin-Paul, Damaceanu Mariana-Dana
"Petru Poni" Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41A, 700487 Iasi, Romania.
Molecules. 2022 Sep 6;27(18):5761. doi: 10.3390/molecules27185761.
Polyazomethines containing electron-donor triphenylamine (TPA) or carbazole (Cbz) and electron-acceptor naphthyl(di)imide were synthesized and investigated with regard to thermal, optical and electronic features, with a focus on their modulation by molecular design. The polycondesation of an imido-based diamine with a Cbz- or TPA-based dialdehyde led to donor-acceptor polymers with good thermostability, up to 318 °C. These displayed good solubility in organic solvents, which enabled easy polymer processability in thin films with different molecular assemblies. The molecular order improved the charge carrier's mobility, with a direct impact on the bandgap energy. The optical properties studied by UV-Vis absorption and fluorescence experiments showed solvent-dependence, characteristic for donor-acceptor systems. The structural parameters exerted a strong influence on the light-emissive behavior, with the prevalence of intrinsic or intramolecular charge transfer fluorescence contingent on the donor-acceptor strength and polymer geometry. All polymers showed good electroactivity, supporting both electrons and holes transport. The exchange of Cbz with TPA proved to be an efficient tool with which to decrease the bandgap energy, while that of naphthyl(di)imide with bis(naphthylimide) was beneficial for fluorescence enhancement. This study may contribute to a deeper understanding of the physico-chemistry of electronic materials so as to make them more competitive in the newest energy-related or other optoelectronic devices.
合成了含有给电子基团三苯胺（TPA）或咔唑（Cbz）以及受电子基团萘基（二）酰亚胺的聚氮杂甲亚胺，并对其热、光和电子特性进行了研究，重点是通过分子设计对其进行调控。基于亚胺的二胺与基于Cbz或TPA的二醛缩聚得到了具有良好热稳定性（高达318°C）的供体-受体聚合物。这些聚合物在有机溶剂中表现出良好的溶解性，这使得它们能够在具有不同分子组装的薄膜中轻松进行聚合物加工。分子有序性提高了电荷载流子的迁移率，直接影响了带隙能量。通过紫外-可见吸收和荧光实验研究的光学性质显示出对溶剂的依赖性，这是供体-受体体系的特征。结构参数对发光行为有很大影响，本征或分子内电荷转移荧光的占比取决于供体-受体强度和聚合物几何结构。所有聚合物都表现出良好的电活性，支持电子和空穴传输。事实证明，用TPA取代Cbz是降低带隙能量的有效手段，而用双（萘酰亚胺）取代萘基（二）酰亚胺则有利于增强荧光。这项研究可能有助于更深入地理解电子材料的物理化学性质，从而使其在最新的能源相关或其他光电器件中更具竞争力。
