Muddassir Mohd, Alarifi Abdullah, Afzal Mohd, Alshali Khulud Abdullah, Abduh Naaser A Y, Beagan Abeer
Catalytic Chemistry Research Chair, Department of Chemistry, College of Science, King Saud University Riyadh 11451 Saudi Arabia
RSC Adv. 2020 Nov 18;10(69):42137-42146. doi: 10.1039/d0ra08073j. eCollection 2020 Nov 17.
In this study, Cu perchlorate complexes of 3,5-dimetylpyrazole(dmpy), namely Cu(dmpy)(HO)(ClO) (1), were prepared and characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), infrared (IR) spectroscopy, elemental analysis, mass spectrometry, and ultraviolet visible (UV-Vis) spectroscopy. It was determined that Cu coordinated to the nitrogen atoms of three dmpy molecules as well as to the oxygen atoms of two HO molecules in a square pyramidal geometry. To balance the charge, two uncoordinated perchlorate anions and one HO molecule were also present in the lattice. The resulting Cu complex was involved in extensive hydrogen bonding, which stabilized the structure. The fluorescence properties of complex 1 were studied in acetonitrile at room temperature upon the addition of different organic solvents. It was confirmed that the complex exhibited remarkable acetone selectivity a fluorescence quenching mechanism. At low concentrations, the fluorescence intensities were nearly completely quenched a turn-off mode. Moreover, complex 1 displayed exceptional selectivity, fast detection time, and high sensitivity for Cd in aqueous solutions a fluorescence enhancement mechanism (turn-on mode). Hence, the prepared complex showed potential for application in Cd detection. Notably, in an aqueous solution, complex 1 exhibited highly selective fluorescence enhancement effects (turn-on mode) with respect to Cd and was not affected by the interference of other metal ions.
在本研究中，制备了3,5 - 二甲基吡唑（dmpy）的高氯酸铜配合物，即Cu(dmpy)(HO)(ClO) (1)，并通过X射线衍射（XRD）、热重分析（TGA）、红外（IR）光谱、元素分析、质谱和紫外可见（UV - Vis）光谱对其进行了表征。确定Cu以方锥几何构型与三个dmpy分子的氮原子以及两个HO分子的氧原子配位。为平衡电荷，晶格中还存在两个未配位的高氯酸根阴离子和一个HO分子。所得的铜配合物参与了广泛的氢键作用，从而稳定了结构。在室温下于乙腈中加入不同有机溶剂时研究了配合物1的荧光性质。证实该配合物表现出显著的丙酮选择性——一种荧光猝灭机制。在低浓度下，荧光强度几乎完全猝灭——一种关闭模式。此外，配合物1对水溶液中的Cd表现出优异的选择性、快速检测时间和高灵敏度——一种荧光增强机制（开启模式）。因此，所制备的配合物显示出在Cd检测中的应用潜力。值得注意的是，在水溶液中，配合物1对Cd表现出高度选择性的荧光增强效应（开启模式），且不受其他金属离子干扰的影响。
