Amphiphilic pyridinium ketoximes 4-[1-(hydroxyimino)alkyl]-1-methylpyridinium bromides (1) and 1-alkyl-4-[1-(hydroxyimino)ethyl]pyridinium bromides (2) are isomeric cationic surfactants bearing the nucleophilic hydroxyimino group. They differ in the position of the nucleophilic function relative to polar head group and hydrophobic alkyl chain. The 4-nitrophenyl diphenyl phosphate (PNPDPP) cleavage by the oximate anions generated from 1 and 2 was used as a model reaction for the investigation of the influence of the structure and lipophilicity of functional surfactants on their reactivity in micelles and microemulsions. The investigation of the model reaction in cationic micelles of hexadecyltrimethylammonium bromide (CTAB), in non-ionic micelles (Triton X-100 and Brij 35) and in o/w microemulsion (isooctane/phosphate buffer/CTAB and butan-1-ol) has revealed that it is the lipophilicity which is the most important factor influencing the localization and reactivity of functional surfactants in nanoaggregates.
两种异构阳离子表面活性剂分别为4-[1-(羟亚胺)烷基]-1-甲基吡啶溴化物(1)和1-烷基-4-[1-(羟亚胺)乙基]吡啶溴化物(2),它们是含有亲核羟亚胺基团的两性分子。它们在亲核功能相对于极性头基团和疏水烷基链的位置上有所不同。通过从1和2生成的羟肟阴离子对4-硝基苯二苯磷酸三酯(PNPDPP)的裂解被用作模型反应,以研究功能性表面活性剂的结构和亲脂性对其在胶束和微乳中的反应性的影响。在正十六烷基三甲基溴化铵(CTAB)的阳离子胶束、非离子胶束(Triton X-100和Brij 35)以及o/w型微乳(异辛烷/磷酸缓冲液/CTAB和正丁醇)中对模型反应的研究表明,亲脂性是影响功能性表面活性剂在纳米聚集体中定位和反应性的最重要因素。