Effect of green solvents on chemical reactions and material formation: characterization of transient intermediates

为了设计工业上相关的化学过程的最佳条件，使对环境的影响最小，我们需要测量许多活性中间体在新型环境友好溶剂中的反应速度。这是我们研究的一个目标。通过专注于基础知识，我们将为绿色溶剂应用的技术发展铺平道路。化学反应中的活性中间体反应如此之快，以至于传统的化学工具无法探测到它们。这是我们在加拿大的TRIUMF国家实验室和英国的卢瑟福·阿普尔顿实验室(目前世界上仅有的三个可比较的实验室中的两个)这两个主要设施进行许多实验的部分原因。最重要的两类绿色溶剂是超临界流体和离子液体。离子液体，像食盐一样，是由带电的碎片组成的。盐溶于水，但需要剧烈加热才能融化。例如，普通的食盐在非常热的806℃下熔化，离子液体具有与食盐相似的性质，但在接近室温时是液体！超临界流体被定义为高于其临界点的物质。临界点代表物质可以作为蒸气和液体平衡存在的最高温度和压力。超临界条件可能高达几百个大气压，高温高达500摄氏度。在这种极端条件下，探测反应中间体需要特殊的设备，这是大多数实验室所没有的。我们在离子液体和这些极端的超临界流体条件下探索活性中间体。我们使用TRIUMF实验中有关活性中间体的微观信息，在我们位于芒特艾利森大学的实验室中设计环境友好型化学工艺。特别是，我们将在超临界流体中制备化合物和材料。

To design optimum conditions for industrially relevant chemical processes, to have the minimum effect on environment, we need to measure the rate of reaction of many reactive intermediates in novel environmentally friendly solvents. This is a goal of our studies. By focusing on the fundamental knowledge we will pave the way for technological developments in applications of green solvents. The reactive intermediates (in chemical reactions) react so fast that conventional chemistry tools cannot probe them. This is part of the reason that we carry out many of our experiments at two major facilities TRIUMF national laboratory in Canada and Rutherford Appleton laboratory in the UK (two of the only three present comparable laboratories in the world). The two most important classes of green solvents are supercritical fluids and ionic liquids. Ionic liquids, like table salt are made of charged fragments. Salts dissolve in water, but need severe heating to melt them. For example common table salt melts at a very hot 806 C. Ionic liquids have the similar properties to table salt but are liquid at close to room temperature! A supercritical fluid is defined as a substance above its critical point. The critical point represents the highest temperature and pressure at which the substance can exist as a vapour and liquid in equilibrium. The supercritical conditions may be as extreme as a few hundred atmosphere of pressure and as high temperature as 500 C. Probing reaction intermediates under such extreme conditions needs extraordinary equipments not available in most laboratories. We probe reactive intermediates in ionic liquids and under these extreme conditions of supercritical fluids. We use the microscopic information on reactive intermediates from our TRIUMF experiments to design environmentally friendly chemical processes in our laboratory at Mount Allison University. In particular we will prepare chemical compounds and materials, in supercritical fluids.