Positional Isomeric Thiophene-Based π-Conjugated Chromophores: Synthesis, Structure, and Optical Properties
Huan Yi, Xi Qin, Lei Zhai, Huiyuan Duan, Huafeng Chen, Yulan Zuo, Xin Lian, Kui Tian, Jinling Zhang, Zhengli Liu, Peng Xu
Abstract
High Resolution Image Download MS PowerPoint Slide A series of positional isomeric chromophores o -TC, m -TC, and p -TC, in which electron-rich thiophene moieties were connected by π-conjugated bridges, were divergently synthesized and characterized. Single-crystal X-ray diffraction analysis revealed an intriguing zipper-like packing mode which was adopted by m -TC in the solid state. Subsequently, UV–vis absorption spectra and fluorescence spectra in a series of solvents were investigated. The nearly coplanar para isomer p -TC was found to have the most intense UV–vis absorption, fluorescence emission, and the highest photoluminescence quantum yield. The molecule structure, electronic nature, and origination of the absorption of p -TC were revealed through density functional theory calculations. Interestingly, all three positional isomers exhibited strong and stable electrochemiluminescence emission, which enriched the existing knowledge on the optical properties of thiophene-based oligomers.