(Z)-3-(Quinolin-2-ylmethylene)-3,4-dihydroquinoxalin-2(1H)-one derivatives: AIE-active compounds with pronounced effects of ESIPT and TICT
作者:Qi-Chao Yao、Xiao-Lin Lu、Min Xia
DOI:10.1039/c3nj01439h
日期:——
A new family of (Z)-3-(quinolin-2-ylmethylene)-3,4-dihydroquinoxalin-2(1H)-one derivatives, which exhibit aggregation-induced emission (AIE) activity, is synthesized and characterized. The qualitative structure property analysis reveals that the emission behaviors of these compounds are closely related to the locations of substituents on the molecules. The density functional theory (DFT) calculations elucidate that excited state intramolecular proton transfer (ESIPT) can smoothly occur in these compounds and a following twisted intramolecular charge transfer (TICT) in the lowest excited singlet state should account for their fluorescence quenching in solution. The restriction of such a TICT process in the aggregated state is assumed as the mechanism for their AIE behaviors.
合成并表征了一种新的(Z)-3-(喹啉-2-亚甲基)-3,4-二氢喹嗪-2(1H)-酮衍生物系列,这些衍生物表现出聚集诱导发射(AIE)活性。定性结构性质分析显示,这些化合物的发射行为与分子中取代基的位置密切相关。密度泛函理论(DFT)计算阐明了激发态分子内质子转移(ESIPT)可以在这些化合物中顺利发生,而在最低激发单态中的随后的扭曲分子内电荷转移(TICT)应解释其在溶液中的荧光猝灭。假设在聚集状态中此类TICT过程的限制是其AIE行为的机制。