1,10‐Phenanthroline–H2O2–KSCN–CuSO4–NaOH oscillating chemiluminescence system

In this paper, oscillating chemiluminescence (CL), 1,10‐phenanthroline H₂O₂–KSCN–CuSO₄–NaOH system, was studied in a batch reactor. The system described is a novel, slowly damped oscillating CL system, generated by coupling the well‐known Epstein–Orban, H₂O₂–KSCN–CuSO₄–NaOH chemical oscillator reaction with the CL reaction involving the oxidation of 1,10‐phenanthroline by hydrogen peroxide, catalyzed by copper(II) in alkaline medium. In this system, the CL reaction acts as a detector or indicator system of the far‐from‐equilibrium dynamic system. Narrow and slightly asymmetric light pulses of 1.2 s half‐width are emitted at 440 nm with an emitted light time of 200–1000 s, induction period of 3.5–357 s and oscillation period of 28–304 s depending on the reagent concentrations. In this report the effect of the concentration variation of components involved in the oscillating CL system on the induction period, the oscillation period and amplitude was investigated and the parameters were plotted with respect to reagent concentrations. Copper concentration showed a significant effect on the oscillation period. The possible mechanism for the oscillating CL reaction was also discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Investigations of different chemiluminescent peaks in H2O2–SCN−–Cu2+–OH−–luminol flow system

In the H₂O₂–SCN^?–Cu²⁺–OH^?–luminol oscillatory system of chemiluminescence, the effects of the ingredient concentrations, temperature, flow rate and complexing agent on the oscillatory dynamics were investigated in a continuous‐flow stirred tank reactor (CSTR). The dynamical structure of two peaks during a period was discussed in detail. By addition of EDTA to the oscillating system, the peak I height decreased sharply while the peak II height was little affected, and the period kept constant. This may be due to the fast reaction between Cu(II) and EDTA and the highly stable complex Cu(II)–EDTA. From the experimental study and mechanism analysis, the chemiluminescent peak I corresponds to Cu(II) → Cu(I) transformation and the peak II corresponds to the Cu(I) → Cu(II) transformation process. The key species involving in the two‐transformation process are inferred to be superoxide radical and hydroxyl radical. Copyright © 2010 John Wiley & Son, Ltd.