Periodic Reporting for period 2 - AE-FUN (Innovative alkaline earth systems for the activation and functionalization of dinitrogen and other challenging substrates)
Reporting period: 2024-06-01 to 2025-05-31
Catalysis has been recognized as a critical tool of contemporary society. However, there are still many limitations of current catalytic methods. For example, ammonia production relies upon the highly energy-intensive Haber-Bosch process, which consumes up to 3% of the global energy produced annually. For this reason, developing new catalytic systems that achieve this transformation in milder conditions are highly desirable.
This EU-funded AE-FUN project aims to develop novel systems based on earth-abundant alkaline earth metals for the challenging conversion of dinitrogen into ammonia and other nitrogen-containing valuable chemicals. We seek to establish the grounds for a promising approach to sustainable catalysis by exploring for the partnership between abundant alkaline earth (Ae) metals in low oxidation states and transition metals (TM). We envisioned that by harnessing the unexplored modes of cooperativity between TM and low-valent Ae metals, new synergies will arise and facilitate the activation of challenging substrates and their functionalization.
This EU-funded AE-FUN project aims to develop novel systems based on earth-abundant alkaline earth metals for the challenging conversion of dinitrogen into ammonia and other nitrogen-containing valuable chemicals. We seek to establish the grounds for a promising approach to sustainable catalysis by exploring for the partnership between abundant alkaline earth (Ae) metals in low oxidation states and transition metals (TM). We envisioned that by harnessing the unexplored modes of cooperativity between TM and low-valent Ae metals, new synergies will arise and facilitate the activation of challenging substrates and their functionalization.
During this period, a series of novel alkaline-earth complexes bearing bulky neutral or anionic ligands have been synthesized. These complexes show great stability towards Schlenk equilibrium, a well-known process which poses an additional difficulty to the obtention of well-defined heteroleptic alkaline-earth complexes. Some of these complexes contain halide groups which make them useful precursors for reactivity and catalysis. These new Ae complexes were characterized by various spectroscopic techniques, including single-crystal x-ray structure determination.
Depending on the ligand framework used, a family of mono-, bi- or polynuclear complexes are obtained. In addition, for a same ligand, the geometry of the resulting complex can also depend on the nature of the Ae metal (Mg gives the potassium ‘ate’ complex, Ca forms dimers; and Sr and Ba form polynuclear clusters).
Depending on the ligand framework used, a family of mono-, bi- or polynuclear complexes are obtained. In addition, for a same ligand, the geometry of the resulting complex can also depend on the nature of the Ae metal (Mg gives the potassium ‘ate’ complex, Ca forms dimers; and Sr and Ba form polynuclear clusters).
During our investigations, in our search for new compounds suitable for the stabilization of low-valent metals, we developed a new series of ligand precursors. In addition, we found that one of these compounds can promote the activation of highly stable aromatic bonds. This ground-breaking result is a major accomplishment and may find a wide range of applications for the activation of strong bonds.