Kinetic and Mechanistic Studies of Highly Reactive Species Containing Electron-Deficient Main Group Atoms, and the Synthesis of Novel Molecules

该项目的目标是了解控制缺电子和多键物种的反应的因素，这些物种包含第13、14和15族的第二、第三和第四行元素。将探索二甲基二硅炔（MeSiSiMe）的生成，以解决含有硅-硅三键的分子的结构和反应性，这是未知的。一类新的缺电子物种在反应性原子上含有四个价电子，既带电（例如Br-C：+和Ph-Si：+）又中性（Ph-B：和Ph-Al：），提供了以协同或逐步方式形成三个新键的能力。新的前体反应stannylenes（R2 Sn：）将允许探索的全方位的反应可用于中性分子含有二价锡原子，没有空间屏蔽取代基的存在下。空间上不受阻碍的lithiosilylenes R（Li）Si：将用于探索三重态硅烯的化学性质，并将启动一项新的计划，用于设计和建造“分子虎钳”，这是刚性支架，能够对安装在钳口之间的二价物质施加预选的大键角。这将允许研究处于不寻常电子状态的分子的光谱和化学，如三重态甲硅烯。活性碳基中间体的研究揭示了有机反应发生的基本机制，为控制有机反应性提供了基本的理解和预测工具。在有机和高分子化学计划的支持下，华盛顿大学化学系的Peter P. Gaspar教授正在研究基于碳族中较重元素-硅，锗和锡的类似物质的制备和反应性。这些研究将导致有机化学的强大的机械思想的扩展，以预测和合理化整个周期表中的键形成和键断裂过程，此外还将提供对控制硅膜化学气相沉积反应的因素的预测性见解，这些硅膜形成了现代半导体工业的基础。

The goal of this project is to understand the factors that control the reactions of electron-deficient and multiply bonded species containing second-, third- and fourth-row elements of groups 13, 14, and 15. The generation of dimethyldisilyne (MeSiSiMe) will be explored in order to address the structure and reactivity of molecules containing the silicon-silicon triple bond, as yet unknown. A novel class of electron-deficient species containing four valence electrons at the reactive atom, both charged (e.g. Br-C:+ and Ph-Si:+) and neutral (Ph-B: and Ph-Al:), offer the capability of forming three new bonds in either a concerted or stepwise manner. New precursors for reactive stannylenes (R2Sn:) will allow the exploration of the full range of reactions available to neutral molecules containing divalent tin atoms, without the presence of sterically shielding substituents. Sterically unencumbered lithiosilylenes R(Li)Si: will be used for the exploration of the chemistry of triplet silylenes, and a new program will be initiated for the design and construction of "molecular vices" that are rigid scaffolds capable of imposing preselected large bond angles on divalent species mounted between the jaws. This will allow the study of the spectroscopy and chemistry of molecules in unusual electronic states like triplet silylenes.The study of reactive carbon-based intermediates has shed light on the fundamental mechanisms by which organic reactions occur, providing both basic understanding and predictive tools for the control of organic reactivity. With the support of the Organic and Macromolecular Chemistry Program, Professor Peter P. Gaspar, of the Department of Chemistry at Washington University, is studying the preparation and reactivity of analogous species based on the heavier elements in the carbon group - silicon, germanium, and tin. These studies will lead to the extension of the powerful mechanistic ideas of organic chemistry to the prediction and rationalization of bond-making and bond-breaking processes throughout the periodic table, and in addition will provide predictive insights into the factors controlling the reactions involved in the chemical vapor deposition of silicon films that form the basis of much of the modern semiconductor industry.