AIE-Active Triphenylamine Push–Pull Chromophores with Multistimuli-Chromism, Electrochemistry, and NLO Response

The rapid advancement of high-tech electronic, photonic, and data-storage technologies has created an urgent demand for organic materials exhibiting strong and tunable nonlinear optical (NLO) properties, as these materials enable ultrafast signal processing, optical modulation, frequency conversion, and high-density information storage. Triphenylamine was employed as the electron-donating unit, while various electron-withdrawing groups were positioned at the termini to construct a series of donor-π-acceptor push-pull chromophores (1-8). These chromophores were systematically characterized using UV-vis spectroscopy, Aggregation-induced Emission behavior, acidochromic, electrochemical studies, and Nonlinear optical and thermal analysis. Theoretical investigations using density functional theory at the B3LYP/6-31G-(d,p) level revealed reduced HOMO-LUMO energy gaps, consistent with the observed electrochemical and optical behavior.