The selective gas adsorption properties of nanoporous materials (NPMs) endow them with many possible applications in the storage , separation [ ], and sensing [ ] of gases. As examples, promising applications of NPMs include (i, storage) densifying hydrogen (H 2 )-a clean fuel-for compact storage onboard vehicles , (ii, separation) capturing carbon dioxide from flue gas of coalfired power plants; subsequently sequester it to prevent global warming [ ], and (iii, sensing) detecting toxic compounds and explosives . Several classes of NPMs, such as metal-organic frameworks (MOFs) [ ], metal-organic polyhedra (MOPs) [ ], covalent organic frameworks (COFs) [ ], and porous organic cages (POCs) [ ], are synthesized modularly by stitching together molecular building blocks via coordination or covalent (COFs, POCs) bonds to form ∼ crystalline (MOFs, COFs) or molecular (MOPs, POCs) materials. The many topologies [ , , ], abundance of molecular building blocks, and post-synthetic modifiability permit an unlimited number of possible structures exhibiting diverse adsorption properties.