Dephosphorylation and aromatic nucleophilic substitution in nonionic micelles. The importance of substrate location
Dephosphorylation and aromatic nucleophilic substitution in nonionic micelles. The importance of substrate location
复制标题
非离子胶束中的去磷酸化和芳香族亲核取代。
DOI：
10.1139/v98-093
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发表时间：
1998
影响因子：
1.1
通讯作者：
C. Whiddon
中科院分区：
文献类型：
--
作者：
C. A. Bunton;H. Foroudian;N. Gillitt;C. Whiddon
非常稀的十二烷基（10）和聚氧乙二醇（23）（分别为C12E10和C12E23）抑制了OH-和F-与对硝基苯二苯基磷酸（pNPDPP）的反应，但在超过临界胶束浓度时，速率常数与表面活性剂浓度无关。低电荷密度阴离子（如ClO4-）抑制低电荷密度阳离子（如（n-C7H15）4N+）加速反应，这可能是通过控制栅栏层中亲核试剂的浓度来实现的。由F-攻击产生的二苯基氟化磷未被检测到，但迅速水解为氟化磷苯基或磷酸二苯基离子，同时失去酚或F-。产品的不同之处在于含有适量水（<15 vol%）和无表面活性剂的DMSO，是由F-攻击初始的氟化磷而产生的氟化磷苯基和二氟磷酸离子。这些差异与胶束栅栏层富水一致。尽管非离子su…
Reactions of OH- and F- with p-nitrophenyl diphenyl phosphate (pNPDPP) are inhibited by very dilute dodecyl (10) and (23) polyoxyethylene glycol (C12E10 and C12E23, respectively), but rate constants become independent of surfactant concentrations at concentrations above the critical micelle concentration. Low charge density anions, e.g., ClO4-, inhibit and low charge density cations, e.g., (n-C7H15)4N+, accelerate reactions, probably by controlling concentrations of nucleophiles in the palisade layer. Diphenyl phosphorofluoridate, generated by attack of F-, is not detected but is rapidly hydrolyzed to phenyl phosphorofluoridate or diphenyl phosphate ion with loss of phenol or F-. The products are different in DMSO containing modest amounts (<15 vol%) of water and no surfactant and are phenyl phosphorofluoridate and difluorophosphate ions generated by attack of F- on the initial phosphorofluoridate. These differences are consistent with the micellar palisade layer being water-rich. Although the nonionic su...