Controlled Reduction of N2 at a Transition Metal Center

描述(由申请人提供)：这项研究的长期目标是确定如何在相对温和的条件下(&lt；100℃和&lt；10 atm)，使用定义明确的过渡金属络合物、质子和电子，或一些含有氮的有机分子，将分子氮催化还原为氨。近期的目标是制备新的Mo、W、V、Fe和Ru的配合物，其中氨基氮上的取代基是一个非常大的间三苯基，并探索与还原氮有关的化学，特别是含有N2Rx(x=0-4)或NRV(y=0-3)配体(R=H或C基或Si基)的配合物的化学。含有这些被稳定的、大体积的间三苯基团取代的多齿三胺胺配体的络合物对双分子分解反应具有抵抗力，并且对质子和电子相对稳定，因此作为氮素还原所必需的十几个中间体在催化循环中可以是稳定的中间体。如果能开发出一种在氮气下将氮素催化还原为氨的系统，就有可能节省大量能源，这些能源用于能源密集型(200-400大气压，350-650摄氏度)、多相、铁催化的哈伯-博世工艺。对于用质子和电子活化和还原氮素具有基本和普遍意义的原理也可能被证明与其他催化反应有关，这些反应涉及许多容易发生双分子分解反应的中间体。

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.