Résumé
The synthesis of stable porous materials with appropriate pore size and shape for desired applications remains challenging. In this work a combined experimental/computational approach has been undertaken to tune the stability under various conditions and the adsorption behavior of a series of MOFs by subtle control of both the nature of the metal center (Co2+, Cu2+, and Zn2+) and the pore surface by the functionalization of the organic linkers with amido and N‐oxide groups. In this context, six isoreticular MOFs based on T‐shaped ligands and paddle‐wheel units with ScD0.33 topology have been synthesized. Their stabilities have been systematically investigated along with their ability to adsorb a wide range of gases (N2, CO2, CH4, CO, H2, light hydrocarbons (C1–C4)) and vapors (alcohols and water). This study has revealed that the MOF frameworks based on Cu2+ are more stable than their Co2+ and Zn2+ analogues, and that the N‐oxide ligand endows the MOFs with a higher affinity for CO2 leading to excellent selectivity for this gas over other species.
Cu‐MOF stability: The stability of a series of isoreticular MOFs has been thoroughly evaluated with regard to the nature of their metal centers (Co2+, Cu2+, and Zn2+) and ligand donors (see figure). The copper‐based MOFs are generally more stable than the cobalt‐ and zinc‐based MOFs. The combined experimental/computational approach employed in this work has demonstrated that both N‐oxide and amido groups play important roles in adsorbate–adsorbent interactions, the former remarkably enhancing the heat of adsorption and CO2/CH4, CO2/CO, and CO2/N2 selectivity at room temperature.