Cyclic Phosphorus and Anionic Silicon Compounds

9312053马萨诸塞大学化学系Robert R. Holmes博士与俄罗斯喀山州立大学Rauza P. Arshinova博士共同参与了美俄合作科学项目的无机、生物无机和有机金属化学项目，以确定决定环四坐标和五坐标硅化合物以及五坐标和六坐标磷化合物性质的特征。俄罗斯小组将制备新的三配位和四配位环磷和硅化合物。这些将被用作由俄罗斯和美国团队合成的五配位环衍生物的前体。这些配合物将通过核磁共振波谱和x射线衍射来确定环构象变化和配体交换现象。理论计算将用于模拟这些过程，并了解在磷和硅的亲核位移反应的能量学。磷和硅的许多反应都涉及一些试剂攻击磷或硅化合物，以产生包含所有反应物质的中间体。该项目将结合美国和俄罗斯团队的专业知识，以确定这些中间体的行为方式以及对它们开放的反应途径。这项工作将特别集中在生化能量传递过程中重要的反应上。

9312053 Holmes University of Massachusetts - Amherst Dr. Robert R. Holmes, Chemistry Department, University of Massachusetts, is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program for a US-Russia Cooperative Science Program with Dr. Rauza P. Arshinova, Kazan State Univ., Russia, to determine features which determine the properties of cyclic four- and five-coordinate silicon and five- and six-coordinate phosphorus compounds. New tri- and tetra-coordinate cyclic phosphorus and silicon compounds will be prepared by the Russian group. These will be used as precursors for five-coordinated cyclic derivatives to be synthesized by the Russian and US groups. These complexes will by studied by NMR spectroscopy and x-ray diffraction to determine ring conformational changes and ligand exchange phenomena. Theoretical calculations will be employed to model these processes and to understand the energetics of nucleophilic displacement reactions at phosphorus and silicon. Many reactions of phosphorus and silicon involve some reagent attacking a phosphorus or silicon compound to produce an intermediate containing all of the reacting species. This project will combine the expertise of a US and a Russian group to determine how these intermediates behave and what reaction pathways are open to them. The work will center particularly on reactions which are important in biochemical energy transfer processes.