Development of a 2D Microwave Spectrometer

在主要研究仪器（MRI）和化学研究仪器和设施（CRIF）计划的支持下，布鲁克斯H。弗吉尼亚大学的Pate将开发一种最先进的激光二维微波光谱仪。 本文介绍了时域分子转动光谱作为研究化学反应动力学的一种新技术。 化学反应被描述为不同局域结构之间的布居转移。 例如，反应可以在不同的电子状态之间发生，其中反应物和产物的电子构型不同。 分子异构化反应可以类似地描述为分子核构型的变化。 反应的一个共同特征是反应构型中的分子结构通常不同。 对于异构化反应，该结果是显而易见的。 对于不同电子态之间的反应，通常存在由两种电子构型的不同成键引起的结构变化。 在化学反应过程中，惯性矩是与时间有关的量。 因此，反应动力学可以通过测量转动光谱的时间演化来确定。 分子光谱学这一新领域的成功发展将使人们有可能解开涉及几种异构体的复杂反应的反应途径。

With support from the Major Research Instrumentation (MRI) and the Chemistry Research Instrumentation and Facilities (CRIF) Programs, Prof. Brooks H. Pate of the University of Virginia will develop a state-of-the-art laser 2D microwave spectrometer. This will introduce time-domain molecular rotational spectroscopy as a new technique to study chemical reaction dynamics. Chemical reactions are described as population transfer between different localized structures. For example, the reaction can take place between different electronic states where the electronic configuration is different for the reactant and product. Molecular isomerization reactions can similarly be described as changes in the nuclear configuration of the molecule. One common feature of reactions is that the molecular structure is usually different in the reacting configurations. For isomerization reactions, this result is readily apparent. For reactions between different electronic states, there is often a structural change caused by the different bonding of the two electronic configurations. During the chemical reaction the moments-of-intertia are time-dependent quantities. The reaction kinetics can, therefore, be determined by measuring the time evolution of the rotational spectrum. The successful development of this new field of molecular spectroscopy will make it possible to unravel reaction pathways for complex reactions involving several isomers.