Dinitrogen chemistry of Ru and Os (quinolinyl)amido complexes

Abstract

The well-developed chemistry of Ru and Os complexes supported by neutral N-donor ligands (e.g., see studies by H. Taube and by T. J. Meyer) has exposed a host of chemically fascinating, multi-electron redox transformations. These include nitride coupling to form N_2 , azide attack at coordinated NO to generate N_2O and N_2 as byproducts, and oxidative O-atom transfer. To derive similarly robust systems that are more reducing in nature, our group has developed a versatile family of electron-rich Ru and Os systems supported by anionic triand bidentate (quinolinyl)amido ligands. Our design scheme allows for selective site exposure at a position trans to an amido functionality, chosen to stabilize a range of oxidation states that should promote desirable group transfer activity. These complexes do appear particularly well-suited to small molecule binding (e.g., N_2, O_2, N_2O). For example, mono- and dinuclear nitrogen complexes of Ru and Os can be systematically prepared under appropriate reaction conditions. In this talk I plan to discuss the emerging chemistry of these Ru and Os systems by emphasizing their synthetic development and their interesting electronic properties. A particular focus will be placed on these data with respect to evaluating the potential of these amido-based systems for N_2 reduction/ functionalization chemistry.