Niedervalente Urankomplexe: Synthese und Aktivierung kleiner Moleküle
Final Report Abstract
Worldwide, research into the activation of small molecules such as N2, CO, and CO2 by transition metal complexes is accelerating, since it provides the opportunity to generate industrially interesting high-value compounds from an almost inexhaustible feedstock. However, the whole potential of low-valent uranium species has not been uncovered so far, for which reason our work focused on the development of novel sterically highly encumbered uranium(III,IV) complexes. Unfortunately, all of our efforts to (i) prepare new chelating, sterically demanding bis- and trisamino ligands, and (ii) to incorporate the well-known Schrock trisamido ligand into the coordination sphere of uranium were unsuccessful, and this project was ended. Consequently, we were also not able to begin Subproject B aiming at the activation of small molecules. Accordingly, we initiated a new project dealing with bis(imino)pyrrole uranium(IV) complexes, which were considered promising candidates in the activation of small molecules as well. This Subproject was more successful, and we were able to isolate the first species of this kind, and to study their simple organometallic chemistry. However, initial experiments at the end of the period did not provide reasonable evidence for the activation of dinitrogen. Thus, this project has also been discontinued.
