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.