阳离子表面活性剂溴代十六烷基吡啶胶束对2,4-二硝基氯苯水解反应的影响

阳离子表面活性剂溴代十六烷基吡啶(CPB)胶束对水中OH^-和2, 4-二硝基氯苯的反应有催化作用.随CPB浓度的增大, 反应速率常数开始时迅速增大, 然后趋于常数.OH^-浓度的增大使胶束催化水解的二级速率常数减小.CPB胶束对此反应的速率提高作用比十六烷基三甲基溴化扶胶束更有效.对这两种胶束催化作用的差异进行了讨论.

Effects of Cationic Surfactant Cetylpyridine Bromide Micelle upon the Hydrolysis of 2,4-Dinitrochlorobenzene

The Ieaction between hydroxide ion and 2, 4 dinitrochlorobenzene in water wascatalyzed by cationic micelles of cetylpyridine bromide (CPB ). The rate constant first increased sharply. then remained relatively constant as the concentration of CPB increased.The kinetic form can be interpreted quantatively in terms of incorporation of substrate andhydroxide ion into the eationic micelles. Increasing the hydroxide ion concentration decreasedthe second-order rate constant of the micellar-catalyzed hydrolysis. The rate enhancement ismore pronounced in CPB than in cetyltrinlethylammonium1 bromide system. The difference ofthe effects of the two cationic micelles has also been discussed.