Porous Zr₆L₃ Metallocage with Synergetic Binding Centers for CO₂

Coordination-driven assembly has been widely successful in the synthesis of metallocages and used for many applications, such as catalysis. However, studies on CO2 adsorption with metallocages have been rarely conducted, compared to other well-known cage-type materials, such as porous organic cages. In this study, a rational choice of ligand and metal led to the synthesis of a Zr6L3-type metallocage, exhibiting exceptional CO2 adsorption properties. CO2 adsorption experiments revealed that the metallocage shows highly selective adsorption of CO2 over N2 with high CO2 binding energy. Density functional theory calculations uncovered the origin of this exceptional affinity for CO2 over N2.