Single transition state in the transfer of a neutral phosphoryl group between phenoxide ion nucleophiles in aqueous solution
作者:Salem A. Ba-Saif、Mark A. Waring、Andrew Williams
DOI:10.1021/ja00178a040
日期:1990.10
reaction of 4-nitrophenolate ion with the 4-nitrophenyl ester is slightly imbalanced whereby bond formation does not keep up with bond fission in the transition states; the transition state, therefore, has some phosphorylium ion character. Transfer of the diethylphosphoryl group between weakly basic oxyanion nucleophiles is probably a concerted process with a transition state with more of the character
取代酚盐离子与磷酸 4-硝基苯基二苯酯反应的二级速率常数 (k ArO ) 服从 18 个取代基范围内的线性方程。线性图与涉及单个过渡态或两步过程的机制一致,中间体具有非常活泼的中间体,其形成和分解的过渡态几乎相同;指数 (0.53) 的值也与具有离散中间体的常规逐步过程不一致。4-硝基苯酚离子与 4-硝基苯酯的对称反应略微不平衡,因此键的形成跟不上过渡态的键裂变;因此,过渡态具有一些磷离子特征。