Towards the synthesis of ligand scaffold for bimetallic systems

Areas ranging from fine chemical synthesis to sustainable energy development rely on highly efficient metal-based catalysts to perform key chemical transformations [1]. Then metals such as Pd, Pt, Rh, Ir or Ru are used because they are proficient at mediating the multi-electron transfer steps required for these applications. In contrast to synthetic chemistry, biological systems do not use noble metals but rather employ cooperative reactivity between multiple redox sites [2]. These sites store and provide additional electrons to avoid unfavorable oxidation states at the reactive centers. However, these cooperative processes remain not well-known, specifically in multi-metallic systems [3]. Then, replicating this strategy of redox cooperativity in synthetic complexes could offer a valuable way to enhance the reactivity of first-row transition metals like iron, copper, etc. To address this challenge, our project seeks to develop and study the biomimetic strategy of incorporating metal-based electron reservoirs within the periphery of reactive metal centers. Thus, ditopic ligands able to interact with two metallic centers have been developed based on N,N,N’,N’-tetra(heterocyclic)propylene- and ethylene-diamines. Modifying the substituents on the heterocycles and the Bite angle may provide interesting properties to our bimetallic systems. For now, their monometallic counterparts have been synthesized and characterized through spectroscopic and electrochemical technics that brought promising results.