Femtosecond Dynamics of Bimolecular Reactions

麦克唐纳教授的资金来自 实验物理化学计划，研究动力学 化学反应过程的时间尺度大约是 250飞秒，使用激光时间分辨光谱学 这种长度的脉冲。 我们的目标是研究反应， 债券制作过程本身的时间尺度。A货车der 含有一个反应物和一个非反应物的Waals簇 分子，可以通过以下方式制成另一种反应物： 光解离提供了一个方便的定义，零的 是时候进行双分子反应了 待研究的反应 包括添加基团和原子H、Cl、Br或甲基 小的双键分子如乙烯。 产品 在冷却的分子束反应中形成的， 通过飞秒泵浦-探测激光荧光或通过 多光子电离飞行时间质谱 侦测 %%% 非常快的激光脉冲将用于频闪技术 研究两种反应物之间的反应， 分子。首先，反应物松散地结合在 一束光开始了反应。 的 届时将用光脉冲进行观测 反应过程本身的规模，看看一个新的 正在联系

Professor McDonald is funded by a grant from the Experimental Physical Chemistry Program to study the dynamics of chemical reaction processes on a time scale of approximately 250 femtoseconds, using time resolved spectroscopy with laser pulses of that length. The goal is to study the reaction in the time scale of the bond-making process itself. A van der Waals cluster containing one reactant and a nonreactive molecule that can be made into the other reactant by photodissociation provides a convenient definition of a zero of time for a bimolecular reaction. The reactions to be studied involve the addition of radicals and atoms H, Cl, Br, or methyl to small double-bonded molecules such as ethylene. Products formed in the reaction in a cooled molecular beam will be detected by femtosecond pump-probe laser fluorescence or by multiphoton-ionization with time-of-flight mass spectroscopy detection. %%% Very fast laser pulses will be used in a stroboscopic technique to study the reaction between two reactants to form new molecules. Starting with the reactants loosely bound in a cluster, a flash of light begins the reaction. The observations will be carried out with light pulsing at the time scale of the reaction process itself to see the making of a new bond in progress.