Chemistry and Applications to Catalysis of Phosphine Complexes of the Platinum Group Elements

在这个项目中，无机，生物无机和 有机化学计划理查德·艾森伯格博士将 利用最近在他的研究中发现的一个新现象， 实验室帕拉激极化，在研究 各种有机金属反应的机理。这 这一现象导致核磁共振强度大大增强 信号，并承诺在一个重大改进 金属氢研究中最重要的工具 交互. 该项目的重点是铂族化学 配合物对于所研究的配合物，大多数配体 是桥接和非桥接二（叔膦）基团， 还有一些氢化物配体一个主要的推力 项目帕拉氢激极化（PHIP），其中 当氢化和氢的存在时， 加成反应使用富含帕拉的 二氢PHIP的观察提供了明确的证据， 一种涉及氢的成对转移的反应机理。 将进行的具体研究将：a）分析PHIP， 其动力学意义; B）用PHIP观察催化 重要中间体：c）检查不对称 加氢和簇氢解反应 d）使用PHIP增强NMR信号， P-31和C-13 NMR光谱。第二个重点是 金属络合物促进的硅烷与主要 目的是催化Si-Si键的形成。一个系列的 研究将调查伯硅烷与 双核配合物最初导致与 双（亚甲硅烷基）桥。SiRH装置的后续耦合将 通过金属中心的协调控制来探索， 氧化还原促进的反应，和通过光解。去除 在硅烷的分解偶联中产生的氢 将通过氢化适当的烯烃来完成。中 相关系列研究单核双和三（甲硅烷基） 复合物将检查关于Si-H与Si-Si 还原消除甲硅烷基络合物的其他反应， 也将研究硅氢化。

In this project in the Inorganic, Bioinorganic and Organometallic Chemistry Program Dr. Richard Eisenberg will take advantage of a new phenomenon recently discovered in his laboratory, para hydrogen induced polarization, in the study the mechanisms of a variety of organometallic reactions. This phenomenon leads to greatly enhanced nuclear magnetic resonance signals, with the promise of significant improvements in one ofthe most important tools used in the study of metal-hydrogen interactions. The focus of the project is the chemistry of platinum group complexes. For the complexes under study most of the ligands are bridging and non-bridging di(tertiary phosphine) groups, with some hydride ligands as well. A major thrust of the project is para hydrogen induced polarization (PHIP) in which unusual NMR enhancements result when hydrogenation and hydrogen addition reactions are performed using para enriched dihydrogen. Observation of PHIP provides definitive evidence of a reaction mechanism involving pairwise transfer of dihydrogen. The specific studies to be performed will: a) analyze PHIP for its kinetic significance; b) use PHIP to observe catalytically significant hydrides and intermediates: c) examine asymmetric hydrogenation and cluster hydrogenolysis reactions using para enriched dihydrogen; and d) use PHIP to enhance NMR signals in P-31 and C-13 NMR spectroscopy. A second thrust focuses on metal complex-promoted reactions of silanes with the principal objective of catalyzing Si-Si bond formation. One series of studies will investigate the reactions of primary silanes with binuclear complexes leading initially to complexes with bis(silylene) bridges. Subsequent coupling of SiRH units will be probed through coordination control of the metal centers, by redox-promoted reactions, and by photolyses. Removal of dihydrogen generated in dehydrogenative coupling of silanes will be done by hydrogenating an appropriate olefin. In a related series of studies mononuclear bis- and tris(silyl) complexes will be examined with regard to Si-H vs Si-Si reductive elimination. Other reactions of silyl complexes such as hydrosilation will be studied also.