菲并咪唑衍生物的化学结构与其热学性质的关系

Relationship between Thermal Properties and Their Chemical Structure in Phenanthroimidazole-Based Material

摘要: 菲并咪唑衍生物由于优异的热力学性能，在制备深蓝光、双极性、高效率的蓝光材料方面逐渐受到关注。本文在本课题组和多个课题组的研究成果基础上，以1,2-二苯基–菲并咪唑作为菲并咪唑衍生物结构的模型化合物，通过改变咪唑环的1,2号位取代基的位置、结构与链接方式，来研究其对玻璃化转变温度和热分解温度的变化影响规律。分析结果显示，玻璃化转变温度除了随分子空间位阻增大而降低，随共轭程度、平面性的增大而升高外，菲并咪唑的2号位取代对其影响更显著；而热分解温度基本上随着分子质量、共轭程度、分子平面性的增大而增加。这些为高热学稳定的菲并咪唑材料设计提供一定参考。

Abstract: Phenanthroimidazole and its derivatives have attracted more and more attention in preparing bipolar and high-efficiency saturated blue emitters due to their excellent thermal properties. To discuss the effect on the glass transi- tion temperature and thermal decomposition temperature originating from the chemical structure change in phenan- throimidazole-based material, such as the linked position and different substituent groups, 1,2-diphenyl-phenan- thro[9,10-d]-imidazole is chosen as a model compound based on the current results. By tuning the substituent structure and linked mode in the imidazole ring 1,2-position, some regularities are revealed. The analysis results show that the Tg decreases with the increase of the molecular steric and rises with the increases of conjugated degree and planarity, simultaneously, 2-position of imidazole ring plays a more important role in all substituent positions. The Td is enhanced with the increase of molecular weight, conjugation and molecular planarity. All of these would provide some valuable suggestions for the design of phenanthroimidazole-based materials with excellent thermal properties.