Kshtriya Vivekshinh, Koshti Bharti, Mehmood Tahir, Singh Ramesh, Joshi Khashti Ballabh, Bandyopadhyay Sujoy, Boukhvalov Danil W, Reddy J Prakasha, Gour Nidhi
Department of Chemistry, Indrashil University, Kadi, Mehsana, Gujarat, 382740, India.
Department of Chemistry, Dr. Harisingh Gour Vishwavidyalaya (A Central University), Sagar, Madhya Pradesh, 470003, India.
Soft Matter. 2022 Apr 13;18(15):3019-3030. doi: 10.1039/d2sm00154c.
We report for the very first time the crystal structure and self-assembly of a new aggregation-induced emission enhancement (AIEE) dye 4-(5-methoxythiazolo[4,5-]pyridin-2-yl)-,-dimethylaniline (TPA) and its application in sensing dichromate ions. TPA reveals cyan blue emission under UV and visible light. The self-assembly properties of TPA were studied extensively by scanning electron microscopy (SEM) which revealed the formation of beautiful flower-like morphologies. These structures revealed both green and red fluorescence under FITC and rhodamine filters respectively when observed through fluorescence microscopy connoting the panchromatic emission properties of TPA from blue to red. The interactions which cause self-assembled structure formation in TPA were also validated theoretically using density functional theory (DFT) calculations. Crystal and molecular structure analysis of TPA was carried out single-crystal X-ray diffraction to visualize the intermolecular interactions occurring in the solid-state and to study the structure-photophysical property relationship in the aggregated state. The photophysical properties of TPA were also studied extensively by UV-visible and fluorescence spectroscopy and its quantum yield and fluorescence lifetime were calculated by time-correlated single-photon counting (TCSPC). Interestingly, TPA could efficiently sense dichromate (CrO) ions in an acidic medium and an interesting morphological transition from a fluorescent flower to non-fluorescent disassembled structures could also be observed. The limit of detection of TPA for CrO ions was found to be as low as 5.5 nM, suggesting its exceptional sensitivity. More importantly, TPA could selectively sense CrO ions in real water samples even in the presence of other metal ions routinely present in polluted water, hence making it practically useful for water quality monitoring.
我们首次报道了一种新型聚集诱导发光增强（AIEE）染料4-(5-甲氧基噻唑并[4,5-]吡啶-2-基)-N,N-二甲基苯胺（TPA）的晶体结构、自组装及其在检测重铬酸根离子中的应用。TPA在紫外光和可见光下呈现蓝青色发射。通过扫描电子显微镜（SEM）对TPA的自组装性质进行了广泛研究，结果显示形成了漂亮的花状形态。当通过荧光显微镜观察时，这些结构在FITC和罗丹明滤光片下分别呈现绿色和红色荧光，这表明TPA具有从蓝色到红色的全色发射特性。还使用密度泛函理论（DFT）计算从理论上验证了导致TPA中形成自组装结构的相互作用。通过单晶X射线衍射对TPA进行晶体和分子结构分析，以可视化固态中发生的分子间相互作用，并研究聚集态下的结构-光物理性质关系。还通过紫外-可见光谱和荧光光谱对TPA的光物理性质进行了广泛研究，并通过时间相关单光子计数（TCSPC）计算了其量子产率和荧光寿命。有趣的是，TPA在酸性介质中能够有效地检测重铬酸根（Cr₂O₇²⁻）离子，并且还可以观察到从荧光花状到非荧光解体结构的有趣形态转变。发现TPA对Cr₂O₇²⁻离子的检测限低至5.5 nM，表明其具有出色的灵敏度。更重要的是，即使在受污染水中常规存在的其他金属离子存在的情况下，TPA仍能在实际水样中选择性地检测Cr₂O₇²⁻离子，因此使其在水质监测中具有实际用途。
