Comparative nucleophilic reactivities in carboxylate, phosphinate, and thiophosphate esters cleavage
作者:Kallol K. Ghosh、Sunita Bal、Sancheeta Kolay、Ashish Shrivastava
DOI:10.1002/poc.1370
日期:2008.6
Nucleophilic substitution reaction of p-nitrophenyl acetate (PNPA), p-nitrophenyldiphenyl phosphinate, and pesticide parathion with different α-nucleophiles [I] have been studied at 27 °C in different pH in the presence of a novel cationic surfactant. The kinetic study was performed spectrophotometrically under pseudo-first order conditions with the α-nucleophile in excess. The pKa of nucleophiles
在新型阳离子表面活性剂的存在下,在27°C和不同pH下研究了对硝基乙酸苯基酯(PNPA),对硝基苯基二苯基次膦酸酯和农药对硫磷与不同α-亲核试剂的亲核取代反应[I]。动力学研究是在伪一级反应条件下用过量的α-亲核试剂进行分光光度法进行的。在P ķ一亲核试剂的数量也已通过动力学方法确定。在表面活性剂的存在下,速率常数随着表面活性剂浓度的增加而增加,直至达到极限值。在胶束催化的假相模型的基础上,已对这种行为进行了定量分析。最后,已将异羟肟酸根离子的亲核反应性与其他α-亲核体进行了比较,如肟,羟基苯并三唑和2-碘代苯甲酸(IBA)。还讨论了亲电中心的裂解顺序,即CO,PO和PS。版权所有©2008 John Wiley&Sons,Ltd.