金属离子对没食子酸(GA)-BZ非催化振荡反应的影响

EFFECTS OF METALLIC IONS ON THE UNCATALYZED OSCILLATIONS IN CALLIC ACID(GA)BZ SYSTEM

测定了一系列金属离子对没食子酸（ＧＡ）－ＫＢｒＯ３－Ｈ２ＳＯ４体系非催化振荡反应的影响。从实验中发现，金属离子对上述振荡反应的影响可分为三类：（１）Ｃｅ３＋、Ｍｎ２＋、Ｆｅ（ｐｈｅｎ）２＋３、Ｂｉ３＋和Ｃｒ３＋，可促进ＧＡ－ＢＺ体系的非催化振荡反应，同时可产生连续振荡等复杂振荡现象；（２）Ｃｕ２＋、Ｚｎ２＋、Ｌ３＋ａ、Ｓｍ３＋、Ｅｕ３＋、Ｎｉ２＋、Ｃｏ２＋、Ｈｇ２＋、Ａｇ＋和Ｈｇ２＋２对振荡反应具有强烈的抑制作用；（３）碱金属和碱土金属离子对振荡反应几乎不发生影响。对上述金属离子的影响机理进行了探索，说明金属离子的电极电势、金属离子与ＧＡ形成络合物或与Ｂｒ－形成沉淀是影响上述振荡反应的主要原因。

The effects of various metallic ions in the uncatalyzed oscillations in gallic acid (GA)-BrO-3-H2SO4 system have been determined.The experimental results showed that their effects could be classified into following three groups:(1) Adding Ce3+,Mn2+,Fe(phen)2+3,Bi3+and Cr3+ promoted the oscillations.The dualfrequency oscillations was also observed in the presence of Ce3+,Fe(phen)2+3;(2)Adding Cu2+,Zn2+,La3+,Sm3+,Eu2+,Ni2+,Co2+,Hg2+,Ag+ and Hg2+2 strongly inhibited the present oscillations;(3)Adding alkline or earthalkline metallic ions had no significant effects.The effecting mechanism of those metallic ions on the oscillations was discussed on the basis of standard potential of the metallic ion electrode couples,with the tentative conclusion that the coordination between the metallic ions and the GA,and the reactions between the metallic ions and Br- may form precipitate.The dualfrequency oscillations observed in the present systems were possibly ascribed to the coupledcatalysis between the organi