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

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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.