| Chemical oscillation is the phenomenon of nonlinearity and nonequilibrium, and it is a chemical system in which some intermediate states vary with time or space in periodic manner. Both the typical B-Z oscillating system(oscillating using Ce4+,Mn2+,[Fe(phen)3]2+or [Ru(bipy)3]2+as catalyst) and tetraazamacrocycle-complexes-catalyzed oscillating chemical reactions have become of great interest in the field of kinetics. Recently, the research for the oscillation chemistry mainly focuses on the design of new oscillator, the study of mechanism model and their application on the analytical field. In this paper, we introduced the summary of chemical oscillating reaction, the specific of the synthesis of the catalyst and the designation of two new oscillators. The specifics were showed in the following four aspects:1. The summary of chemical oscillating reactionIt introduced progress on chemical oscillation in the filed of kinetics and thermodynamics. It also introduced the six species of the chemical oscillation and three conditions for occurrence of the chemical oscillation. At last, it was showed the application on the analytical determination of the analytes.2. Systhesis of macrocyclic complex [Ni(TIM)](ClO4)2.The catalyst([Ni(TIM)](C104)2) was synthesized according to literature, then was identified by elementary analysis, infrared spectrum and UV-Vis spectrum. The structure of the [Ni(TIM)] (ClO4)2 was high symmetry, and it contained two conjugated N=C-C=N structural units.3. A new B-Z oscillating reaction catalyzed by a tetramethyl tetraaza-cyclotetradeca-tetraene (TIM) nickel (Ⅱ) complex with malic acidas organic substrateA new B-Z oscillator of the NaBrO3-Malic acid-H2SO4-[Ni(TIM)](ClO4)2 system is reported, among which the TIM is 2,3,9,10-tetramethyl-1,4,8,11-tetraaza-cyclotetradeca-1,3,8,10-Tetraene. The complex [Ni(TIM)](ClO4)2, with a macrocyclic ligand containing two conjugated N=C-C=N structural units, can serve as a catalyst in the titled system. It is found that the oscillation period (tp) is dependent on the initial concentrations of DL-malic acid and H2SO4, but it is independent on the concentrations of BrO3-. So the oscillation period tp can be expressed as: tp(s)∞[NaBrO3]00[H2S04]0-1.23[Malic acid]0-0.29. The experiments results have shown that the concentrations of Br- may act as an on-off switch while free radicals and HBrO2 may be involved in the oscillating process. A tentative mechanism based on the FKN is proposed.4. New B-Z oscillating reaction catalyzed by a tetramethyl tetraazacyclotetradeca-tetraene Nickel (Ⅱ) complex [Ni(TIM)](ClO4)2In this paper, a new B-Z oscillating reaction in which a tetramethyl tetraazacyclotetradeca-tetraene (TIM) Nickel (Ⅱ) complex [Ni(TIM)] (ClO4)2 serves as catalyst and Citric acid as organic substrate in aqueous H2SO4 is reported. The experimental results have shown that the different concentrations of NaBrO3, H2SO4 and Citric acid have effects on the oscillation period(tp), the amplitude of oscillation (A), and the oscillating cycles (n). It is found that the oscillation period(tp) is dependent on the initial concentrations of NaBrO3, H2SO4 and Citric acid. The oscillation period tp can be expressed as:tp(s)∞[NaBrO3]0-2.003 [H2SO4]0-2.881 [Citric acid]0-3.16. The effect of some reducing agent, free radicals, Ag+, Hg2+ on the oscillation is also studied. A tentative mechanism based on the FKN is proposed latter. |
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