Pericyclic Transition Structures

在有机动力学计划的这个项目中，Henry J. Shine教授将在德克萨斯理工大学化学系研究“周环过渡结构”。Shine教授正在与罗切斯特大学化学系的William H. Saunders教授合作。在这项研究中，测量了带有特定标记底物的重原子动力学同位素效应，并进行了键序建模计算，以定义已知为周环反应的过渡结构。​重原子（碳、氮和氧）的动力学同位素效应（KIE）和键序建模计算是为了确定几个周环反应的过渡结构。所研究的反应有芳香克里森重排（烯丙基苯基醚）、联苯胺重排（肼苯）和脂肪族克里森重排（烯丙基乙烯基醚及其两个衍生物）。芳香clisen重排和联苯胺重排的目的是利用它们沿反应坐标探测不直接参与断键和成键的碳原子的耦合运动。在脂肪族重排中，clisen的目标是定义它们的过渡结构和共时性，这在理论处理中引起了争议。建模计算将使KIE适合键的顺序，因此，优化的过渡结构。

In this project in the Organic Dynamics Program, Professor Henry J. Shine will study "Pericyclic Transition Structures" in the Chemistry Department at Texas Tech University. Professor Shine is collaborating with Professor William H. Saunders in the Chemistry Department at the University of Rochester. In this study heavy atom kinetic isotope effects with specifically labelled substrates are being measured and bond order modeling calculations are being carried out in order to define the transition structures of reactions that are known to be pericyclic. Heavy atom (carbon, nitrogen, and, oxygen) kinetic isotope effects (KIE) and bond order modeling calculations are being made in order to define the transition structures of several pericyclic reactions. Reactions being studied are the aromatic Claisen rearrangement (allyl phenyl ether), the benzidine rearrangement (hydrazobenzene), and the aliphatic Claisen rearrangement (allyl vinyl ether and two of its derivatives). The objective in the aromatic Claisen rearrangement and in the benzidine rearrangement is to use them to probe along the reaction coordinate for coupled motion of carbon atoms not directly involved in bond breaking and making. In the aliphatic Claisen rearrangements the objective is to define their transition structures and synchronicities, over which controversy has arisen from theoretical treatments. Modeling calculations will be made to fit KIE to bond orders and, hence, to optimized transition structures.