四氮杂大环四烯镍(Ⅱ)参与的连续振荡化学反应

Sequential Oscillations Involving a Nickel (Ⅱ) Complex with Me_4 [14] traeneN_4

本文报道了一种新型振荡化学反应体系BrO_3^-—没食子酸—H_2SO_4—四氮杂大环四烯镍(Ⅱ)配合物连续振荡化学反应体系,四氮杂大环为2,3,9,10—四甲基—1,4,8,11—四氮杂环十四—1,3,8,10—四烯,研究了可出现连续振荡(间歇式振荡)现象的浓度范围,并提出了简要的振荡机理。

Sequential oscillations were firstly reported by Hall and Waterton Nearly all these kinds of oscillations were observed only with mixed organic substrates in B-Z system.In this paper, we present experimental evidence that [Ni(TIM)]2+ can act as an catalyst in bromate-gallic acidsulfuric acid system to produce sequential oscillation, where TIM is 2, 3, 9, 10-tetramethyl-1, 4, 8, 11-tetraazacyc lote tradeca-1, 3, 8, 10-tetraene.When bromate solution is finally added to the reaction mixture,two sets of concen-tration oscillations take place, as shown in Figure. The first set of oscillation is the noncatalyzed oscillation of the bromate-gallic acid-sulfuric acid system, and the second set of oscillation ( after a transition state) is the [Ni(TIM) ]2+ catalyzed oscillation of the systen.The ranges of concentration of the main components within which sequential oscillations are observed have been determined. The second set of oscillation viz. [Ni(TIM)]2+ catalyzed one is damped mainly due to the accumulating of free bromine during the reaction, not to the slow consumption of the catalyst [Ni(TIM)]2+. It is different from the other tetraazamacrocyclic nicke (Ⅱ) or copper (Ⅱ) complexes as catalyst. It is new type of chemical oscillation. The mechanisms of the oscillating reaction is suggested and briefly discussed.