分子间相互作用对芳杂环聚合物PBO光谱性能影响的理论研究

采用量子化学计算方法AM1-ZINDO/CI对芳杂环聚合物PBO的光物理性能进行研究。结果表明:PBO分子链共轭平面结构间的面面相互作用,影响到前沿分子轨道的电子跃迁方式,从而导致聚集态电子光谱相对于理论单分子链存在红移现象。由含3个单元的PBO聚集态分子模型模拟计算显示,PBO分子链共轭平面结构间的面面相互作用使得电子光谱最大吸收峰由383.06 nm红移至407.19 nm。结合同系线性规律,推导出PBO聚合物聚集态的电子光谱最大吸收峰为425.33 nm,从本征结构上解释了PBO聚集态电子光谱的光谱性质。

Theoretical Studies of the Influence of Intermolecular Interactions on the Photophysical Properties of Poly (p-phenylene-2,6-benzobisoxazole) (PBO)

The photo-physical properties of hetero-aromatic(poly(p)-phenylene-2, 6-benzobisoxazole)(PBO) were studied by a quantum chemistry calculation method AM1-ZINDO/CI.The interfacial action between two conjugated planar structures of the PBO molecules affected the transition of the electrons on the fronted molecular orbit,resulting in a red shift in the electronic spectrum of the aggregated polymer compared to that of the theoretical mono-molecular chain.The analog computation of the PBO congeries molecular model,which is composed of three repeated units,shows that the interfacial action between two conjugated planar structures of the PBO molecules makes the maximum(absorption)-peak of electronic spectrum a red shift from 383.06 nm to 407.19 nm.Based on the homologous linear rule,the maximum(absorption)-peak of the electronic spectrum of the PBO molecule is deduced to the 425.33 nm.The spectrum characteristic of the electronic spectrum of the PBO congeries is explained from its intrinsic structure.