Surfactant Micellar and Vesicle Microenvironments and Structures under Synthetic Organic Conditions.
Surfactant Micellar and Vesicle Microenvironments and Structures under Synthetic Organic Conditions.
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合成有机条件下的表面活性剂胶束和囊泡微环境和结构。
DOI：
10.1021/jacs.3c01574
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发表时间：
2023
影响因子：
15
通讯作者：
Blum,SuzanneA
中科院分区：
文献类型：
--
作者：
Peacock,Hannah;Blum,SuzanneA
荧光寿命成像显微镜（FLIM）揭示囊泡的大小，结构，微环境，试剂分区，和系统的演变与两个化学反应的广泛使用的表面水系统的条件下，相关的有机合成，包括在根岸交叉偶联反应的步骤。与以前的调查相比，本实验表征表面活性剂系统与代表性的有机卤化物基板在高浓度（0.5 M），这是反射的反硝化规模的有机反应，在水中进行和报告。在存在代表性有机底物2-碘代嘌呤和2-溴-6-甲氧基吡啶的情况下，胶束溶胀成直径高达20 μm的乳液液滴，这比先前在不存在有机底物的情况下测量的（5-200 nm）大3-4个数量级。在这些系统中的试剂的分区是通过FLIM成像-这里展示了非极性，两亲性，有机，碱性和氧化加成反应性化合物，反应性锌金属粉末，和钯催化剂。FLIM表征化学物质和/或提供胶束和囊泡内的微环境信息。这些数据表明，表面活性剂在较小的胶束（<200 nm）内引起表面活性剂决定的微环境，但加入代表性的有机底物会产生主要由底物而不是表面活性剂决定的内部微环境，同时伴有溶胀。钯催化剂的加入导致囊泡之间的内部环境不同，这是通过现有分析技术无法获得或预测的信息。总之，这些数据提供了立即可操作的信息，用于修改支持水中可持续有机化学发展的地表水系统的反应模型。
Fluorescence lifetime imaging microscopy (FLIM) reveals vesicle sizes, structures, microenvironments, reagent partitioning, and system evolution with two chemical reactions for widely used surfactant–water systems under conditions relevant to organic synthesis, including during steps of Negishi cross-coupling reactions. In contrast to previous investigations, the present experiments characterize surfactant systems with representative organohalide substrates at high concentrations (0.5 M) that are reflective of the preparative-scale organic reactions performed and reported in water. In the presence of representative organic substrates, 2-iodoethylbenzene and 2-bromo-6-methoxypyridine, micelles swell into emulsion droplets that are up to 20 μm in diameter, which is 3–4 orders of magnitude larger than previously measured in the absence of an organic substrate (5–200 nm). The partitioning of reagents in these systems is imaged through FLIM─demonstrated here with nonpolar, amphiphilic, organic, basic, and oxidative-addition reactive compounds, a reactive zinc metal powder, and a palladium catalyst. FLIM characterizes the chemical species and/or provides microenvironment information inside micelles and vesicles. These data show that surfactants cause surfactant-dictated microenvironments inside smaller micelles (<200 nm) but that addition of a representative organic substrate produces internal microenvironments dictated primarily by the substrate rather than by the surfactant, concurrent with swelling. Addition of a palladium catalyst causes the internal environments to differ between vesicles─information that is not available through nor predicted from prior analytical techniques. Together, these data provide immediately actionable information for revising reaction models of surfactant–water systems that underpin the development of sustainable organic chemistry in water.