Abstract:

Synthesis and investigation of the chemiluminescence of Luminol is a valuable educational and pedagogical tool. In recent years, a few domestic universities started offering this experiment to undergraduate students. To further enrich the scientific and theoretical understanding of the synthetic and chemiluminescent process, we have improved the existing experiments in several ways. First, we introduced mechanical stirring, sulfur-mediated reduction, and microwave chemistry in the synthesis portion to achieve safe, rapid, and efficient preparation of high purity Luminol. Second, we introduced the Luminol/H₂O₂/SCN⁻/Cu²⁺/OH⁻ system for chemiluminescence oscillation, which involves applying important concepts such as kinetics, autocatalysis, non-equilibrium thermodynamics, and dissipative structures. Finally, to achieve real-time quantitative monitoring of the light intensity and frequency of the chemiluminescence oscillating process, we designed a simple miniature magnetic stirring heating device, which can be used in conjunction with a fluorescence spectrometer. Students can design comparison experiments independently and explore the mechanism. This experiment involves combining several important multidisciplinary chemical concepts. The precise measurement of the chemiluminescence oscillating process has effectively captured the interest of students.

Key words: Sulfur-mediated reduction, Microwave-assisted synthesis, Chemiluminescence oscillation, Real-time monitor