Zeolitic imidazolate frameworks (ZIFs) are porous crystalline materials with structures similar to zeolites but with functionalized organic links and a high density of transition metal ions. The structure of ZIFs is determined by link–link interactions, leading to systematic variations in linker substituents and diverse topologies. This paper reports the synthesis and characterization of two novel ZIFs, ZIF-95 and ZIF-100, which exhibit complex cages with up to 264 vertices and 7,524 atoms. These materials are chemically and thermally stable, with high porosity and surface areas. Both ZIFs selectively capture carbon dioxide from various gas mixtures at room temperature, with ZIF-100 capable of storing 28 liters of CO2 per liter of material at standard temperature and pressure. Their high selectivity and stability make ZIFs promising candidates for carbon dioxide capture and storage, offering a potential solution to reduce atmospheric CO2 levels.Zeolitic imidazolate frameworks (ZIFs) are porous crystalline materials with structures similar to zeolites but with functionalized organic links and a high density of transition metal ions. The structure of ZIFs is determined by link–link interactions, leading to systematic variations in linker substituents and diverse topologies. This paper reports the synthesis and characterization of two novel ZIFs, ZIF-95 and ZIF-100, which exhibit complex cages with up to 264 vertices and 7,524 atoms. These materials are chemically and thermally stable, with high porosity and surface areas. Both ZIFs selectively capture carbon dioxide from various gas mixtures at room temperature, with ZIF-100 capable of storing 28 liters of CO2 per liter of material at standard temperature and pressure. Their high selectivity and stability make ZIFs promising candidates for carbon dioxide capture and storage, offering a potential solution to reduce atmospheric CO2 levels.