Group 14 reactive intermediates

该计划涉及研究短寿命分子的化学，这些分子是硅、锗和锡分子反应中的中间体。尽管这些“活性中间体”通常只存在一小部分秒，但通常是它们的化学作用主要负责给定的化学反应如何发生，以及它的效率如何。对活性中间体及其化学的研究对于了解成键和结构的基本方面、化学反应是如何发生的以及设计对社会有用的新的化学工艺或材料非常重要。我们的工作包括直接检测活性中间体并在它们因化学反应而消失时对它们进行监测。它还包括测量它们的反应速率，并最终确定这些反应发生的机制。由于这些分子的反应性非常高，通常会很快消失，我们使用脉冲激光从我们在实验室中首次合成的稳定分子中产生它们，并使用快速的时间分辨光谱方法来监控它们的形成和衰变。它们以这种方式形成是光化学反应的结果，因此，要想成功，我们还必须了解“稳定的”前体分子的光化学。这是通过各种化学和光谱技术进行研究的。一旦确定了一种给定的活性中间体的有效前体，并以众所周知的方式进行反应，那么就有可能利用化学来设计可能对社会有用的新材料或工艺，这是我们工作的长期目标之一。我们的大部分工作涉及研究以本质上不稳定的键排列的高活性分子，所有这些分子在有机化学中都有类似物。我们正在探索控制这些分子的反应性的各种因素。它们的反应机制以及它们如何随分子结构而变化，并更好、更详细地了解涉及第14族元素的类似成键安排之间的相互关系。

The program involves the study of the chemistry of short-lived molecules which are involved as intermediates in the reactions of silicon-, germanium-, and tin-containing molecules.  These "reactive intermediates" typically exist for only a small fraction of a second, but it is their chemistry that is usually primarily responsible for how a given chemical reaction takes place, and how efficiently it does so. The study of reactive intermediates and their chemistry is very important in understanding fundamental aspects of bonding and structure, how chemical reactions take place, and for designing new chemical processes or materials that are useful to society.  Our work involves the direct detection of reactive intermediates and monitoring them as they go away due to chemical reaction.  It involves measuring the rates of their reactions, and ultimately defining the mechanisms by which these reactions take place. Because these molecules typically disappear very quickly due to their very high reactivity, we use pulsed lasers to generate them from stable molecules that we first synthesize in the laboratory, and fast time-resolved spectroscopic methods to monitor their formation and decay. Their formation in this way occurs as a result of a photochemical reaction, and so to be successful, we must also understand the photochemistry of the "stable" precursor molecules. This is studied by a variety of chemical and spectroscopic techniques.  Once an efficient precursor to a given reactive intermediate which reacts in well-understood ways is identified, then it is possible to exploit the chemistry for the design of new materials or processes which may be useful to society, which is one of the long-term goals of our work.   Most of our work involves the study of highly reactive molecules containing silicon, germanium, or tin in intrinsically unstable bonding arrangements, all of which have analogues in organic chemistry.  We are exploring the various factors that control the reactivities of these molecules, the mechanisms of their reactions and how they vary with molecular structure, and developing a better, more detailed understanding of the inter-relationships between like bonding arrangements involving the Group 14 elements.