Femtosecond Studies of Chemical Reaction Dynamics in Liquids

加州大学伯克利分校的查尔斯·哈里斯(Charles Harris)得到了无机化学、生物无机化学和金属有机化学计划的支持，该计划研究相当复杂的有机金属反应的动力学(在飞秒时间尺度上)和密切的机制。利用飞秒红外光谱与高压技术相结合，将阐明各种复杂化学反应的密切机制。将特别注意溶剂分子在这些反应中的作用。最初的兴趣将集中在过渡金属络合物对选择性C-H和Si-H键断裂的激活上。还将研究各种更复杂的反应，包括炔烃聚合。将借助随机动力学模拟来解释反应动力学。一些理论方法，包括从头计算和密度泛函方法，将被应用于中间体的表征。这项研究将研究溶液-无机反应的密切机制的时间范围扩大了几个数量级。通过其他措施即刻做出的反应的细节将受到审查。到目前为止，这种难以接近的化学变化是反应网络中的临界点，而反应网络在许多科学和技术领域具有核心重要性。这项研究可能具有重要意义的主题的具体例子包括对光合作用和呼吸作用等生物过程机制的研究，以及对化学工业中至关重要的金属催化聚合的改进。

Charles Harris of the University of California, Berkeley is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program for research on the kinetics (at the femto-second time scale) and the intimate mechanisms of rather complex organometallic reactions. Using femtosecond infrared spectroscopy coupled with high pressure techniques, the intimate mechanisms of a variety of complex chemical reactions will be elucidated. Special attention will be paid to the role of solvent molecules in these reactions. Initial interest will be centered on the activation by transition metal complexes of selective C-H and Si-H bond ruptures. A variety of more complex reactions, including alkyne polymerization, will also be examined. Reaction dynamics will be interpreted with the aid of stochastic dynamic simulations. Several theoretical methods, including ab initio calculations and density functional methods, will be applied to characterization of intermediates. This research is extending the time range accessible in the study of the intimate mechanisms of solution-phase inorganic reactions by several orders of magnitude. The details of reactions that are instantaneous by other measures will be brought under examination. Such heretofore inaccessible chemical changes stand at critical points in networks of reactions that are of central importance in many scientific and technological areas. Specific examples of topics where this research may have great importance include studies of the mechanisms of biological processes such as photosynthesis and respiration, and also improvement of metal-catalyzed polymerizations that are of central importance in the chemical industry.