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

为了设计工业相关化学过程的最佳条件，使其对环境的影响最小，我们需要测量许多活性中间体在新型环保溶剂中的反应速率。这是我们研究的一个目标。通过关注基础知识，我们将为绿色溶剂应用的技术发展铺平道路。反应性中间体（在化学反应中）反应如此之快，以至于传统的化学工具无法探测它们。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（世界上仅有的三个类似实验室中的两个）进行许多实验的部分原因。两类最重要的绿色溶剂是超临界流体和离子液体。离子液体，比如食盐，是由带电碎片构成的。盐可溶于水，但需要加热才能融化。例如，普通食盐在806℃时融化。离子液体与食盐具有相似的性质，但在接近室温时是液体。超临界流体被定义为高于临界点的物质。临界点表示物质能以蒸汽和液体的平衡状态存在的最高温度和压力。超临界条件可能极端到几百个大气压，温度可能高达500摄氏度。在这种极端条件下探测反应中间体需要大多数实验室都没有的特殊设备。我们在离子液体和超临界流体的这些极端条件下探测活性中间体。我们利用从我们的TRIUMF实验中获得的反应中间体的微观信息，在我们位于埃里森山大学的实验室设计环境友好的化学工艺。特别地，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.