0003690<br/>Holroyd<br/><br/>This award supports a two-year collaborative research project between Dr. Richard Holroyd of the Brookhaven National Laboratory in New York and Professor Masaru Nishikawa of the Kanagawa Institute of Technology in Japan. The researchers will undertake a study of charged species in supercritical fluids - how clustering affects ionic reactions. Achieving an understanding of how ions are solvated by supercritical solvents such as carbon dioxide and ethane is important in fundamental chemical research. The clustering of supercritical fluid solvent molecules around a neutral solute molecule has been intensively investigated using spectroscopic methods since the 1980's and now almost established. However, the clustering around an ionic molecule has attracted attention in the last ten years. The researchers will extend their measurements and theoretical interpretation to charge transfer reactions. They will produce anionic solvent molecules by electron attachment after picosecond pulse radiolysis and try to follow the electron transfer to solute molecules with both time-dependent fluorescent and conductivity measurements. Such measurements clarify the applicability of the compressible continuum model to ionic reactions in supercritical fluids. <br/><br/>The project brings together the efforts of two laboratories that have complementary expertise and research capabilities. Results of this research could form the basis for the analysis of ionic organic reactions in supercritical fluids, which are now extensively investigated as a technology for the next century. This research advances international human resources through the participation of a postdoc. Through the exchange of ideas and technology, this project will broaden our base of basic knowledge and promote international understanding and cooperation. The researchers plan to publish results of their research in scientific journals and report on the findings at scientific meetings.