Phosphinidenes - Structures, Mechanisms, and Reactions

本研究的重点是对过渡金属稳定的膦酸酯的广谱研究，与未络合的三重态膦酸酯相比，它们被认为是单线态的。磷二烯三单能隙将通过高水平从头计算确定，这也将用于表征环加成途径的结构和电子特征，产物稳定性，异构化和p -异聚化。机理研究将确定烯烃环加成的动力学（绝对速率和相对速率）、热力学（激活焓和熵）和立体选择性数据（反/正比）。膦烯将用于合成高应变环体系，包括烷基烯-膦烷、磷酸3放射烯、膦烷、磷酸双环丁烷、由芳香族化合物如buckminister富勒烯衍生的膦烷，以及由杂烯烃衍生的新杂环。有了这个奖项，有机动力学项目支持了阿拉巴马大学伯明翰分校化学系的Koop Lammertsma博士的研究。Lammertsma教授将把他的工作重点放在探索与过渡金属稳定的磷脂有关的独特的类碳烯性质上。这项研究将包括复杂的计算、反应机制的详细分析和一系列的合成应用。

The focus of this research is a broad spectrum study of the transition metal stabilized phophinidenes, which are believed to be singlets in contrast to the uncomplexed triplet phosphinidenes, R-P. Phospinidene triplet-single energy gaps will be determined by high level ab initio calculations, which will also be used to characterize structural and electronic features of the cycloaddition pathways, product stabilities, isomerizations, and P-epimerizations. Mechanistic studies will determine kinetic (absolute and relative rates), thermodynamic (activation enthalpies and entropies), and stereoselectivity data (anti-/syn-ratios) for olefin cycloadditions. Phosphinidenes will be used to synthesize highly strained ring systems, which include alkylidene-phosphiranes, phospha 3 radialenes, phosphaspiranes, phosphabicyclobutanes, phosphiranes derived from aromatic compounds such as buckministerfullerene, and new heteroycles from heteroolefins. With this award, the Organic Dynamics Program is supporting the research of Dr. Koop Lammertsma of the Department of Chemistry at the University of Alabama at Birmingham. Professor Lammertsma will focus his work on the exploration of the unique-carbene-like properties associated with transition metal stabilized phosphinidenes. The study will involve a blend of sophisiticated calculations, detailed analyses of reaction mechanisms, and a spectrum of synthetic applications.