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

将生成各种高活性中间体，并对其反应机理进行研究。这些高活性中间体将通过光解和适当前体的热解产生。这些物质的衰变动力学将由激光闪光光解后的时间分辨光谱学来研究。这些中间体的化学反应性将通过捕集实验和产物研究来探索。待研究的分子包括含有二价硅、锗和锡原子的物质，分别为硅烯、锗烯和锡烯。将六价电子一价亚烯（R-N:）和膦烯（R-P:）的反应路径，以及四价电子一价硼烯（R-B:）和铝基烯（R-Al:）的反应路径与相应的碳烯、硅烯和二甲苯的反应路径进行比较。分子将由新型键合成，包括硅-硅、硅-锗三键和硅-过渡金属双键。新的环形系统也将准备好。来自有机动力学项目的这笔拨款支持了华盛顿大学彼得·p·加斯帕教授的继续工作。反应性中间体将生成，其中包含硅、锗、锡、磷、铝和硼原子，这些原子的键补体比正常的键补体少。这些活性中间体将由稳定的前体分子通过光解和热解方法生成。这些中间产物分解的步骤以及这些过程发生的速率将被研究。通过将这些反应性中间体与其他分子相结合，可以得到它们存在的更直接证据。这些捕获实验的结果将揭示中间体的结构。含有硅的化合物——硅单键和双键是已知的。现在，用硅-硅和硅-锗三键合成的反应性更强的分子。新的环形系统也将准备就绪。

Various highly reactive intermediates will be generated and a study will be made of their reaction mechanisms. These highly reactive intermediates will be generated by photolysis and by pyrolysis of appropriate precursors. Decay kinetics of these species will be followed by time-resolved spectroscopy following laser flash photolysis. Chemical reactivity of these intermediates will be probed through trapping experiments and product studies. The molecules to be studied include species containing divalent silicon, germanium, and tin atoms, namely, silylenes, germylenes, and stannylenes, respectively. Reaction pathways for the monovalent six-valence-electron species nitrenes (R-N:) and phosphinidenes (R-P:), and of the monovalent four-valence-electron borylenes (R-B:) and aluminylidenes (R-Al:) will be compared with reaction paths for the corresponding carbenes, silylenes, and germylenes. Molecules will be synthesized with new kinds of bonds, including silicon-silicon and silicon-germanium triple bonds, and silicon-transition metal double bonds. New ring systems will be prepared as well. %%% This grant from the Organic Dynamics Program supports the continuing work of Professor Peter P. Gaspar at Washington University. Reactive intermediates will be generated that contain silicon, germanium, tin, phosphorous, aluminum, and boron atoms that have less than their normal complement of bonds. These reactive intermediates will be generated from stable precursor molecules by photolysis and by thermolysis methods. The steps by which these intermediates decompose will be studied as well as the rate at which these processes occur. More direct evidence for these reactive intermediates will be given by trapping them with other molecules. The products of these trapping experiments will reveal the structure of the intermediates. Compounds with silicon- silicon single and double bonds are known. Now even more reactive molecules will be synthesized with silicon-silicon and silicon- germanium triple bonds. New ring systems will also be prepared.