Controlled Reduction of N2 at a Transition Metal Center

描述（由申请人提供）：本研究的长期目标是确定如何在相对温和的条件下（<100摄氏度和<10大气压）使用定义明确的过渡金属络合物、质子和电子将分子氮催化还原为氨，或还原为含有氮的某些有机分子。近期目标是制备Mo、W、V、Fe和Ru的新络合物，其含有三酰胺基/供体配体，其中酰胺基氮上的取代基是极其庞大的间三联苯基团，并探索与二氮还原相关的化学，特别是含有N2 Rx（x = 0-4）或NRv（y = 0-3）配体（R = H或基于C或基于Si的基团）的络合物的化学。含有这些被稳定的大体积间三联苯基团取代的多齿三酰氨基胺配体的络合物对双分子分解反应具有抗性，并且对质子和电子也相对稳定，使得在二氮还原中作为必要中间体的十几个中间体可以是催化循环中的稳定中间体。如果能够开发出在双氮下将双氮催化还原为氨的系统，则其具有节省大量能量的潜力，所述能量用于能量密集型（200-400大气压，350-650摄氏度）、非均相、铁催化的哈伯-博施工艺。对于用质子和电子活化和还原二氮具有基本和普遍意义的原理也可能被证明与涉及许多倾向于双分子分解反应的中间体的其他催化反应有关。

DESCRIPTION (provided by applicant): The long-term objectives of this research are to determine how molecular nitrogen can be reduced to ammonia catalytically under relatively mild conditions (<100 degrees C and <10 atm) employing a well-defined transition metal complex, protons, and electrons, or to some organic molecule that contains nitrogen. The near-term objective is to prepare new complexes of Mo, W, V, Fe, and Ru that contain triamido/donor ligands in which the substituent on the amido nitrogens is an extremely bulky m-terphenyl group, and to explore chemistry that is relevant to the reduction of dinitrogen, especially the chemistry of complexes that contain N2Rx (x = 0-4) or NRv (y = 0-3) ligands (R = H or a C-based or Si-based group). Complexes that contain these multidentate triamidoamine ligands substituted by stable, bulky m-terphenyl groups are resistant to bimolecular decomposition reactions, and also are relatively stable to protons and electrons, so that the dozen or so intermediates that are necessary intermediates in dinitrogen reduction can be stable intermediates in a catalytic cycle. If a system that will catalytically reduce dinitrogen to ammonia under dinitrogen can be developed, it has the potential of saving huge quantities of energy that are used in the energy-intensive (200-400 atm, 350-650 degrees C), heterogeneous, iron-catalyzed, Haber-Bosch process. Principles that are of fundamental and general significance to the activation and reduction of dinitrogen with protons and electrons may also prove to be relevant to other catalytic reactions that involve many intermediates prone to bimolecular decomposition reactions.