The main group element chemistry of polypnictogen complexes

• Applicants: Professor Dr. Peter Roesky; Professor Dr. Manfred Scheer
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 470309834

In recent years, the development of new methods to convert white phosphorus (P4) into higher-value products has increased significantly. As an alternative to the use of the reactive P4 molecules as P source, the utilization of metal-stabilized polyphosphide-based systems is an elegant approach. What is more, the heavier homologs of phosphorus, i.e. arsenic and antimony, are, in their elementary form, either too unreactive or extremely difficult to handle so that their integration into organometallic compounds is the better choice. In our preliminary work, we were mainly focused on the targeted functionalization of [Cp*Fe(P5)] with reactive compounds of the main groups II-IV. Here, [Cp*Fe(P5)] served as an air-stable polyphosphorus source. In our investigations, we succeeded in achieving selective substitutions of the P atoms, ring expansions or insertion reactions and rearrangement reactions. Within the scope of this project, we intend to significantly expand the spectrum of pnictogen transition metal complexes as starting compounds and address the following research topics: a) in the field of phosphorus chemistry, we want to investigate as to what extent the substitution or ring expansion reactions observed so far can be generalized and systematized beyond [Cp*Fe(P5)]; b) the spectrum of ring and cage compounds will be extended to the heavy pnictogens and, here in particular, to arsenic in order to obtain fundamental reaction pathways; c) the following reaction types will be investigated in order to enable targeted syntheses in the future: ring or cage expansions, ring or cage contractions, rearrangements; d) in a rather risky work package, we will try to detach the pnictogen ligands from the metal after functionalization to access new systems composed of mixed main group elements.

• DFG Programme: Research Grants