| In this study new oscillations system have been constructed by introducing 1,4-cyclohexanedion (CHD) into the ferroin- or cerium-catalyzed classic BZ reaction as a second organic substrate further. Since 1,4-CHD alone is capable of forming a chemical oscillator with bromate in an acidic environment, the presence of 1,4-CHD actually implements new autocatalytic nonlinear feedbacks. As a result the mixed BZ reaction actually consists of two bromate oscillators that are coupled together through such reagents as bromine dioxide, metal catalysts (ferroin/ferriin or Ce3+/Ce4+) etc. This is unique difference from existing studies of the BZ reactions using mixed organic substrates.; Various complex oscillatory behaviors such as sequential oscillations and burst phenomena have been observed in this coupled oscillator. It is found that the development of complex oscillations depends on the ratio of [1,4-CHD]/[metal catalyst] and [1,4-CHD]/[MA] rather than their absolute concentrations, indicating that competitions between the1,4-CHD and metal catalyst for the bromine dioxide radicals and the competition between 1,4-CHD and malonic acid play the essential role in the observed complex oscillations. (Abstract shortened by UMI.)... |
