Interaction of luminol with the oscillating system H2O2-KSCN-CuSO4-NaOH

Abstract

Two types of oscillating chemiluminescence are observed when luminol is added to the oscillating system H2O2-KSCN-CuSO4-NaOH. Narrow bursts of light, with intensity proportional to the concentration of luminol, occur at the same time as the sharp increase in the concentration of a copper peroxide complex that is a key species in the oscillation of the luminol-free system. A second set of broad, low-intensity oscillations is apparent at luminol concentrations below 10-4 M. These are ascribed to the slower reaction of luminol with superoxide. A skeleton mechanism for the action of luminol is proposed, but testing it will require refinement of the mechanism of the H2O2-KSCN-CuSO4-NaOH oscillator. © 1990 American Chemical Society.