Reactions in Supercritical Fluids: Experimental and Simulation Studies of Microscopic Phenomena

溶解在超临界流体溶剂中的溶质的反应性的实验观察的基础上的微观现象还没有得到很好的理解。 有各种各样的现象，其中可能涉及包括溶剂的整体性能，溶剂吸积周围的溶质分子，和周围的溶质分子的优先集群。 反应速率一般取决于溶质碰撞频率和每次碰撞的寿命;微观行为可能影响其中之一或两者。 如果没有这些效应如何结合联合收割机来确定反应速率的详细描述，用于给定反应的定制超临界溶剂的工程设计将是不可行的。 私家侦探计划从两个方面解决这个问题。 首先，将进行一组物理实验研究，调查宏观和微观行为作为本体溶剂性质的函数，并利用几个独立的实验技术（局部介电测量，海森堡自旋交换）。 与物理测量相一致，将进行计算实验研究，以提供整个分子图像的实验无法访问的部分，再次使用补充技术（布朗动力学，分子动力学）。 每一种方法都将为另一种方法的发展提供支持，从而使用适用的理论来理解这些系统。

The microscopic phenomena which underlie experimental observations for reactivity of solutes dissolved in supercritical fluid solvents are not well understood. There is a wide variety of phenomena which may be implicated including solvent bulk properties, solvent accretion around solute molecules, and preferential clustering of solute molecules around one another. Reaction rates in general depend on both the solute collision frequency and the lifetime of each collision; the microscopic behavior may affect either or both. The engineering design of custom supercritical solvents for a given reaction will not be feasible without a detailed picture of how these effects combine to determine the reaction rate. The PI's plan to attack this problem on two fronts. First, a set of physical experimental studies will be undertaken, investigating both the macroscopic and the microscopic behavior as a function of bulk solvent properties, and utilizing several independent experimental techniques (local dielectric measurement, Heisenberg spin exchange). In concert with the physical measurements, computational experimental studies will be carried out with a view to supplying the experimentally inaccessible portions of the overall molecular picture, again using complementary techniques (Brownian dynamics, molecular dynamics). Each of the approaches will feed the development of the other, leading to an understanding of these systems using the applicable theory.