Iron Methylidyne and Carbide Complexes: Synthesis, Characterization, and Reactivity

• Applicant: Sadig Aghazada, Ph.D.
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 545922088

In this project, we aim to isolate iron complexes with terminal methylidyne and carbide ligands. Although transition metal oxo and nitrido complexes have received much attention, their analogs with isoelectronic methylidyne and carbide ligands remain unexplored. The latter ligands have been partially realized for some earlier 4 and 5d elements and have yet to be reported for 3d elements. Terminal methylidyne and carbide complexes of 3d metals, especially those of iron, are highly sought species that will help uncover novel carbon-atom transfer reactivity and provide a context for a better understanding of the elementary steps in Fischer-Tropsch-type syntheses. The conventional approaches to access mid- and late-3d metal oxo and nitrido complexes have not been fruitful in the synthesis of the corresponding methylidyne and carbide complexes. Thus, herein we suggest alternative approaches that can be useful in accessing such unprecedented complexes. We propose auxiliary ligands that will increase the covalency of iron-carbon multiple bonding and reduce the carbon's electrophilicity, rendering such species isolable. A combination of synthetic routes will be employed. Methylidyne and carbide ligands will be accessed through oxidative conversion of alkyls, reductive activation of carbonyls and cyanides, or using novel atom transfer approaches. The synthesized complexes will be thoroughly analyzed with various tools to construct a detailed picture of their electronic structures. The comparison with nitrides and oxides will help to realize their difference from the carbides and help to explain the reasons behind a carbide center in nitrogenases.

• DFG Programme: Research Grants