Intramolecular charge transfer dual fluorescent sensors from 4-(dialkylamino)benzanilides with metal binding site within electron acceptor
作者:Li-Hong Liu、Han Zhang、Ai-Fang Li、Jian-Wei Xie、Yun-Bao Jiang
DOI:10.1016/j.tet.2006.08.024
日期:2006.10
intramolecular charge transfer (CT) dual fluorescent sensors for metal cations with metal binding site within the electron acceptor. These sensors were derived from 4-dialkylaminobenzanilides (alkyl=methyl, ethyl, and n-butyl) with the amido phenyl ring being an arm of 15-crown-5 thus bearing binding site for alkaline and alkaline earth metal cations. Compounds 2a–c were expected to have two possible CT channels
设计了三个氟离子载体(2a – c)作为分子内电荷转移(CT)双荧光传感器,用于在电子受体内具有金属结合位点的金属阳离子。这些传感器衍生自4-二烷基氨基苯甲酰胺(烷基=甲基,乙基和正丁基),酰胺基苯环为15冠-5的臂,因此带有碱金属和碱土金属阳离子的结合位点。预期化合物2a – c具有两个可能方向相反的CT通道。2a – c及其无冠醚模型分子3a – c的吸收光谱和荧光光谱记录了在各种溶剂中的溶解度。在2a – c处观察到双重荧光,并分别分配为LE和CT状态。在非极性或极性较小的溶剂中,CT出现在2a – c处,这被确定为与苯甲酰苯胺(BA)以酰胺基苯胺为电子供体时发生的CT(BA-like CT),而在极性溶剂中,例如乙腈(ACN), CT仍然主要类似于BA。在ACN中存在碱金属和碱土金属阳离子的情况下,CT双荧光发生了实质性变化,如总量子产率提高,LE谱带红移和CT与LE强度比提高。金属阳离子在2a