New Amidophosphine Complexes of the Early Transition Metals: C−H-Activation and Homogeneous Catalysis
The development of amidophosphine-based hybrid ligands and the synthesis of novel complexes incorporating these ligands lies at the very heart of our research. Along these lines, we have designed a number of significantly new hybrid ligands with different charges and unprecedented topologies. In addition to trianionic tripods, we also prepared dianionic molecular claws and meridionally coordinating pincer ligands in our laboratory already. As a result of their design, some of our complexes are prone to cyclometallation, which often allows for the isolation of C−H-activated complexes. Starting from these specpies, reactive hydrido complexes or species that originate from transient hydrides can be prepared. In our laboratory, we employ such complexes to accomplish intriguing stoichiometric and catalytic reactions (see illustration shown below).
Fundamental Research on 2,2'-Diphospinotolanenes and Their Multifaceted Reactivities
2,2’-Diphosphinotolanes are composed of one central alkyne unit flanked by two trans-preorganized phosphine donors. Due to this preorganization, these particular tolane derivatives are well-suited for the synthesis of [PCCP]-coordinated pincer complexes. Over the course of our studies, however, we have not only observed the formation of pincer complexes, but we also found that the ligand might undergo cyclisation reactions. While the former pincer complexes were shown to effectively catalyze ROMP polymerizations and hydrogenation reactions, the latter cyclized structures were easily oxidized to highly fluorescent dications (see illustration shown below). These structures are currently explored with respect to their application as novel functional materials.
The Coordination Chemistry of Phosphite-Phosphorane-Systems
In this project, we are aiming towards a deeper understanding of certain equilibria between phosphites and phosphoranes, given that these equilibria may be exploited for the construction new phosphinoalkoxides and their complexes. We are currently preparing our first publication on this topic. Further information and structural details on the species under investigation will be added to this webpage in near future.