ИСТИНА

One of the main fundamental scientific problems is the search for energy sources alternative to hydrocarbon fuels. Since hydrogen can be used as an alternative energy carrier, the development of hydrogen energy requires safe systems for storing and transporting high-purity hydrogen. As such systems, chemical compounds can be used - amine-boranes (R1xNH(3-x)BH(3-y)R2y, where R1,R2 = Alk, Ar), containing a large amount of hydrogen by weight. They are stable under standard conditions, provide an appropriate balance of volumetric and gravimetric energy densities with the release of high purity hydrogen. Catalytic dehydrogenation of amine-boranes in the presence of transition metal complexes makes it possible to control the conditions and amount of hydrogen produced. However, at present the most efficient catalysts for the dehydrogenation of amine boranes are complexes based on platinum group metals. In this regard, the development of alternative catalysts based on more common, inexpensive, and less toxic 3d metals (Mn, Zn, Fe, Co, Ni) is of economic and environmental interest. Despite the fact that manganese is an attractive candidate in terms of its abundance and biocompatibility, studies of manganese complexes in the reactions of catalytic dehydrogenation of amine-boranes have practically not been carried out. The planned detailed study of the ability of manganese (I) complexes to catalyze the dehydrogenation of amine-boranes is certainly relevant. In recent years, the Laboratory of Metal Hydrides of INEOS has been actively developing an approach to studying the dehydrogenation of amine-boranes (RR'NH-BH3, where R, R' = H, Alk) with transition metal complexes under stoichiometric and catalytic conditions. It consists in a stepwise study of reactions with obtaining the spectral characteristics of the intermediates and the kinetic parameters of individual stages of the process, which makes it possible to reveal the role of various factors in the activation of reagents and catalysts, as well as to stabilize the reaction intermediates. The combination of experimental methods with quantum chemical calculations makes it possible to establish the reaction mechanism, which makes it possible to purposefully optimize the conditions to achieve efficient hydrogen evolution. The combination of modern physical and physico-chemical methods for studying the structure of matter and high-level quantum-chemical calculations ensures the reliability and reliability of the results obtained. Within the framework of the project, it is planned to obtain a series of manganese complexes with bidentate phosphorus and carbene ligands with various donor-acceptor properties, study their catalytic activity, and also establish the mechanisms of catalytic processes accompanied by hydrogen evolution. On the basis of experimental and theoretical data, mechanisms will be proposed and energy profiles of the reaction will be constructed, the influence of the ligand environment of manganese complexes on their reactivity will be revealed, and the ability of bromide/hydride/cationic complexes of manganese (I) to bifunctional cooperative activation of NH/BH bonds will be established, taking into account the presence of various acidic and basic Lewis sites. This will provide a deeper understanding of the mechanism of the dehydrogenation of amine-boranes in the presence of manganese complexes and the possibility of fine-tuning the processes of activation of M-X, M-H, E-H bonds and will allow us to propose a concept for the purposeful creation of efficient homogeneous hydrogen production catalysts based on manganese complexes. In addition to solving the main task of the project, the results obtained will contribute to the development of the chemistry of manganese catalysts for processes involving the stages of proton and hydride ion transfer, for example, (de)hydrogenation, activation of C-H bonds, hydrofunctionalization, etc.