Nonlinear phenomena in light-mediated bromate-hydroquinone-benzoquinone reactions

This study presents an experimental investigation of nonlinear dynamics in the photomediated bromate-1,4-benzoquinone-1,4-hydroquinone reaction, in which the copresence of hydroquinone and benzoquinone results in chemical oscillations taking place shortly after mixing all reagents together, which is in great contrast to the case of a few hours of induction time seen in the bromate-hydroquinone or bromate-benzoquinone photochemical oscillators. It is essential to keep the acid concentration low in order to achieve these oscillations. Measurements with mass spectrometry and UV/vis spectroscopy confirm the formation of hydroquinone-benzoquinone complexes. The results suggest that interactions of hydroquinone and benzoquinone can play a significant role in the kinetics of related chemical systems.