Nitrogen Schiff Base complexes as selective catalysts for the Valorization CO2 as cyclic carbonates

SSCI-VIDE+CDFA+LCHInternational audienceOur studies focus on nitrogen Schiff bases since these N4 ligands are similar to porphyrins (N4 ligands) and Salen compounds (N2O2 ligands). Nitrogen Schiff bases (BS-4N), present an open structure that can be flexible and chiral, when prepared from the corresponding chiral diamine by a Schiff condensation with an aldehyde. Thus, we developed a series of nitrogen Schiff bases (BS-4N) complexes using various metals (Ni, Co, Cu, Zn, Mn, Fe) and characterized them by spectroscopic methods (NMR, IR, Raman, Mössbauer) and XRay when suitable crystals were obtained [1].As many catalysts are described with porphyrins and salen ligands, the prepared BS-4N complexes may have interesting catalytic properties. The presentation will focus on the use of Nitrogen Schiff Base complexes as catalysts for the carbon dioxide addition to epoxides and the optimization of experimental conditions to form selectively cyclic carbonates. The reactions were carried in liquid phase and supercritical conditions, thus having CO2 as solvent and substrate [2-3]. A theoretical approach on the reaction mechanism will aslo be discussed [4]