Temperature‐Dependent Separation of CO2 from Light Hydrocarbons in a Porous Self‐Assembly of Vertexes Sharing Octahedra

Design of flexible porous materials where the diffusion of guest molecules is regulated by the dynamics of contracted pore aperture is challenging. Here, a flexible porous self‐assembly consisting of 1D channels with dynamic bottleneck gates is reported. The dynamic pendant naphthimidazolylmethyl moieties at the channel necks provide kinetic gate function, that enables unusual adsorption for light hydrocarbons. The adsorption for CO2 is mainly dominated by thermodynamics with the uptakes decreasing with increasing temperature, whereas the adsorptions for larger hydrocarbons are controlled by both thermodynamics and kinetics resulting in an uptake maximum at a temperature threshold. Such an unusual adsorption enables temperature‐dependent separation of CO2 from the corresponding hydrocarbons. A porous flexible supramolecular material that is composed of vertexes sharing octahedra is assembled from dimeric [Mn2L2Cl2]2+ bearing pendant naphthimidazolylmethyl arms. The self‐assembly is characteristic of the channels with small dynamic gates. The local dynamics of the pendant naphthimidazolylmethyl arms leads to unusual diffusion‐regulatory adsorption of light hydrocarbons, thus leading to temperature‐dependent separation of CO2 from the corresponding hydrocarbons.