Exploration of the chemistry of diazine-based redox-active ligands in iron chemistry

• Applicant: Dr. Dragos-Adrian Rosca
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 456077681

Redox-active ligands constitute a valuable instrument for controlling the oxidation states and reactivity of first row transition metals. Amongst these, pyridine-based NNN and PNP pincers represent the ligands of choice of a considerable number of catalytic systems based on sustainable metals. This research programme focuses on the less developed diazine based pyrazine- and pyrimidinediimine ligands which will be used in synergy remote site activation in order to explore new reactivity patterns in iron chemistry. The first part of the programme will focus on the chemistry of pyrazinediimine iron complexes. Here, we have already shown that this structural motif can simultaneously act both as an NNN pincer and as an N-heterocyclic carbene, yielding heterobimetallic complexes. We will further explore the redox chemistry of these systems with a focus on coordination chemistry and small molecule activation. Furthermore, the effect of Lewis acids on the ground state of pyrazinediimine-ligated iron catalytically active species will be investigated. The second part of the programme will investigate the catalytic activity of pyrimidineiimine iron complexes. The initial focus will be on cycloaddition reactions, where intramolecular and intermolecular [2+2] and [2+2+2] reactivity will be explored. A special attention will be given on mechanistic studies and on the isolation of catalytically active species.

• DFG Programme: Research Grants