Contrasting Extremes Among Homologous Transition Metal Complexes: Eliciting Enhanced Reactivity

该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，帮助他合成和研究异常富含电子的酰胺配体(RNPR2)2N(-)和卡宾配体(RNPR2)2C：的络合物。就给电子能力而言，这两个配体类别是截然相反的极端。这两种配体都将用于形成中间过渡金属(主要但不完全是Re)的络合物，并将评估这些络合物裂解正常不反应的C-H、C-C和C-F键的能力。基本的假设是，金属络合物的前线轨道占有率和能量可以通过改变配体的电子给体/受体能力来调节。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。这项建议中要研究的化学对于基本了解均相催化剂的行为是很重要的。这项工作的目的是为合理开发新的、有用的金属介导的化学过程提供基础。在发现新的成键模式和反应模式之后，将尝试将这些信息用于设计新的试剂和催化剂，用于重要的化学过程。

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.