溴离子对BZ非催化振荡反应的影响

Br~-对Belousov-Zhabotinsky(BZ)振荡反应起着控制作用。近来发现,一些有机物在被BrO_3~-氧化时,即使没有金属离子Ce~(3+),Mn~(2+),Fe(phen)_3~(2+),也可产生振荡反应,称为非催化BZ振荡反应。本文选择酪氨酸(Tyr)-BrO_3~--H_2SO_4 BZ振荡体系,对Br~-的影响作了系统的研究,对机理作了初步探索。

STUDY ON THE EFFECTS OF BROMIDE ION ON THE UNCATALYZED BZ OSCILLATING REACTION

Bromide ion (Br~-) is the controlling intermediate in the classical Belousov-Zhabotinsky (BZ) oscillating reaction. In this paper, the effects of Br~- on the uncatalyzed BZ oscillating reaction have been investigated systematically on the basis of tyrone (Tyr)-BrO_3~--H_2SO_4 system. It is found that the experimental results were quite similar to that in the classical BZ oscillating reaction. When some of Br was added initially into the oscillating system, the uncatalyzed BZ oscillation was inhibited temporally. If the Br~- added was more than 0.012mol.dm~(-3), the oscillation was inhibited completely. The Br~- could also inhibit the uncataltzed oscillation when it was added during the oscillation. If some AgNO_3 was added into the oscillating system to remove Br~- by AgBr, it could increase the induction period, but decrease the oscillating number and the oscillating life time. All of the experimental results showed that the oscillation could take place only if the concentration of Br~- was in certain range. The oscillation would be inhibited if the concentration of Br~- was beyound the range. Thus in the uncatalyzed BZ oscillation, Br~- also could play the controlling role, The effecting mechanism of Br~- had been analyzed.