Synthesis, fluorescence, and anticancer activity of silver(I) complex based on 2-hydroxyquinoxaline ligand

The reaction of 2-hydroxyquinoxaline ligand with silver nitrate in anhydrous methanol leaded to the formation of complex [Ag·(L)·(NO₃)] (<b>1</b>) (L = 2-hydroxyquinoxaline). This complex is characterized by FT-IR spectrometer, elemental analysis, X-ray photoelectron spectroscopy (XPS), and X-ray single-crystal diffraction. The results show that <b>1</b> belongs to the monoclinic, <i>P</i>2₁/<i>c</i> space group, with <i>a</i> = 13.9949(12) Å, <i>b</i> = 9.2241(7) Å, <i>c</i> = 7.3110(10) Å, <i>α</i> = 90°; <i>β</i> = 101.945(11)°; <i>γ</i> = 90°, <i>V</i> = 923.34(17) ų, Mr = 316.03. The solid-state fluorescence tests show that the fluorescence intensity of <b>1</b> is stronger than L, and it is accompanied by a blue shift phenomenon. The activity studies have shown that <b>1</b> has good anti-cancer activity with human cancer cells <i>BEL-7404</i>, <i>A549</i>, <i>HepG2</i>, and <i>NCI-H1650</i>, and their IC₅₀ are less than 15 µg/mL. It can be seen that the silver-based complex not only has a good fluorescence response, but also has good anticancer activity.

将2-羟基喹喔啉配体与硝酸银在无水甲醇中反应，得到配合物[Ag·(L)·(NO₃)]（编号为<b>1</b>，其中L=2-羟基喹喔啉）。该配合物通过傅里叶变换红外光谱仪（FT-IR）、元素分析、X射线光电子能谱（XPS）以及X射线单晶衍射进行了表征。表征结果显示，配合物<b>1</b>属于单斜晶系，空间群为<i>P</i>2₁/<i>c</i>，晶胞参数如下：<i>a</i> = 13.9949(12) Å，<i>b</i> = 9.2241(7) Å，<i>c</i> = 7.3110(10) Å；<i>α</i> = 90°，<i>β</i> = 101.945(11)°，<i>γ</i> = 90°，晶胞体积<i>V</i> = 923.34(17) ų，相对分子质量<i>M</i>_r = 316.03。固态荧光测试结果表明，配合物<b>1</b>的荧光强度强于配体L，且伴随蓝移现象。活性研究显示，配合物<b>1</b>对人癌细胞株BEL-7404、A549、HepG2及NCI-H1650均表现出良好的抗癌活性，其IC₅₀值均低于15 μg/mL。由此可见，该银基配合物不仅具备优异的荧光响应性能，同时拥有良好的抗癌活性。