Two superaromatic terpyridine ligands (1 and 2) incorporating a corannulene unit at the 4′-position are reported. The optical and metal sensing properties of both ligands were investigated by the naked eye, and UV-vis and fluorescence spectroscopy in this work. In 1, the corannulene motif is directly connected to the 4′-phenylterpyridine domain, while in 2, the corannulene motif and the 4′-phenylterpyridine domain are separated by an acetylene linker. Both 1 and 2 can work as chemosensors for metal ions and display different optical responses to various metal ions. It is shown that both ligands exhibit a colorimetric sensing ability for Fe2+ through an obvious color change from colorless to magenta, and this color change can be observed easily by the naked eye. The addition of Fe2+ also leads to significant changes in the absorption spectra of the ligands. A characteristic red shift in the emission spectra is observed in the presence of Zn2+, which facilitates the discrimination of Zn2+ from other metal ions. In addition, density functional theory (DFT) and time-dependent-density functional theory (TD-DFT) calculations were performed and shown to be consistent with the observed experimental results.
报道了两种在4′位含有碗烯单元的大环芳香性三联
吡啶配体(1和2)。通过裸眼观察以及紫外-可见光谱和荧光光谱法研究了这两种
配体的光学和
金属离子传感性质。在1中,碗烯基团直接连接到4′-苯基三联
吡啶域,而在2中,碗烯基团和4′-苯基三联
吡啶域通过一个
乙炔连接基团分开。1和2均可用作
金属离子的
化学传感器,并对不同
金属离子显示出不同的光学响应。结果表明,这两种
配体通过从无色到洋红色的明显颜色变化,展现出对Fe²⁺的可视化传感能力,这种颜色变化可以轻松地通过裸眼观察到。添加Fe²⁺还会导致
配体吸收光谱的显著变化。在存在Zn²⁺的情况下,观察到发射光谱的特征红移,这有助于将Zn²⁺与其他
金属离子区分开来。此外,还进行了密度泛函理论(DFT)和含时密度泛函理论(TD-DFT)计算,结果与实验观察结果一致。