Kinetic demonstration of premicellar aggregation. The alkaline hydrolysis of N-hexadecyl-4-cyanopyridinium bromide
作者:N. Hioka、M.J. Politi、H. Chaimovich
DOI:10.1016/s0040-4039(01)80356-7
日期:1989.1
The critical micelle concentration (CMC) of N-hexadecyl-4-cyanopyridinium (HCP) bromide, determined by conductivity or fluorescence quenching, was 7–8 ∗ 10-4 M. The observed rate constants for the hydrolysis of HCP below the CMC increased with the concentration of this amphiphile from 2 ∗ 10-6 M up to the CMC. The product ratio (pyridone/amide) also varied with HCP concentration. The analysis of both
Ionic liquid crystals derived from 4-hydroxypyridine
作者:Jung-Tang Lu、Ching-Kuan Lee、Ivan J. B. Lin
DOI:10.1039/c0sm01376e
日期:——
depending on the site (N or O) of alkylation. Further alkylation of these two neutral compounds yielded ionic liquid crystals (ILCs) of N-alkyl-4-alkoxypyridinium bromide, having two long alkyl chains. Alternatively, simple protonation of the two neutral compounds with HCl also induced the formation of ILCs of N-alkyl-4-hydroxypyridinium chloride or 4-alkoxypyridinium hydrochloride. Crystal structures
取决于烷基化的位点(N 或 O),4-羟基吡啶的单烷基化产生中性 N-烷基-4-吡啶酮或 4-烷氧基吡啶。这两种中性化合物的进一步烷基化产生了具有两条长烷基链的 N-烷基-4-烷氧基溴化吡啶的离子液晶 (ILC)。或者,两种中性化合物与 HCl 的简单质子化也诱导形成 N-烷基-4-羟基吡啶鎓氯化物或 4-烷氧基吡啶鎓盐酸盐的 ILC。通过单晶 X 射线衍射确定了两种不同类型的离子液晶和一种中性化合物的晶体结构。通过差示扫描量热法、偏光显微镜和粉末 X 射线衍射法检查中间相性质。阴离子影响二烷基化化合物中中间相的结构和稳定性。利用核磁共振扩散级谱技术研究了一些典型化合物在溶液中的自组装行为。最后,制备并表征了由吡啶鎓盐稳定的稳定的金纳米颗粒。