Contrasting Extremes Among Homologous Transition Metal Complexes: Eliciting Enhanced Reactivity

无机、生物无机和有机金属化学项目的这一奖项为印第安纳大学化学系的Kenneth G. Caulton博士提供了持续的支持，以合成和研究一种异常富电子的酰胺配体（RNPR2）2N（-）和一种异常吸电子的碳配体（RNPR2）2C:)的复合物。这两类配体在给电子能力方面处于相反的极端。这两种配体都将用于形成中间过渡金属的配合物（主要是，但不完全是Re），这些配合物切割通常不反应的C-H， C-C和C-F键的能力将被评估。基本的假设是，金属配合物的前沿轨道占用和能量可以通过改变配体的电子供体/受体能力来调整。因此，金属影响各种反应的能力可以通过适当的配体选择来调节。本提案中所要研究的化学对于获得对均相催化剂行为的基本理解是重要的。本工作的目的是为合理开发新的和有用的金属介导的化学过程提供基础。在发现新的键合模式和反应模式之后，将尝试将这些信息用于设计用于重要化学过程的新试剂和催化剂。

This award in the Inorganic, Bioinorganic, and Organometallic Chemistry Program provides continued support to Dr. Kenneth G. Caulton of the Chemistry Department, Indiana University, for the synthesis and study of complexes of an unusually electron-rich amide ligand, (RNPR2)2N (-), and a carbene ligand, (RNPR2)2C:, that is exceptionally electron withdrawing. Together these two ligand classes are at opposite extremes in terms on electron donating ability. Both ligands will be used to form complexes of mid-transition metals (largely, but not exclusively, Re) and the ability of these complexes to cleave normally unreactive C-H, C-C, and C-F bonds will be evaluated. The underlying hypothesis is that the frontier orbital occupancy and energy of a metal complex can be tailored by varying the electron donor/acceptor ability of the ligand. Thus, the ability of a metal to effect various reactions can be tuned by proper ligand choice. The chemistry to be studied in this proposal is important to obtaining a basic understanding of the behavior of homogeneous catalysts. The goal of this work is to provide a basis for the rational development of new and useful metal-mediated chemical processes. The discovery of new bonding patterns and reactivity modes will be followed by attempts to use this information in the design of new reagents and catalysts for significant chemical processes.