Hierarchically porous metal–organic frameworks (HP‐MOFs) have attracted great attention owing to their advantages over microporous MOFs in some applications. Despite many attempts, the development of a facile approach to generate HP‐MOFs remains a challenge. Herein we develop a new strategy, namely the modulation of cation valence, to create hierarchical porosity in MOFs. Some of the CuII metal nodes in MOFs can be transformed into CuI via reducing vapor treatment (RVT), which partially changes the coordination mode and thus breaks coordination bonds, resulting in the formation of HP‐MOF based on the original microporous MOF. Both the experimental results and the first‐principles calculation show that it is easy to tailor the amount of CuI and subsequent hierarchical porosity by tuning the RVT duration. It is found that the resultant HP‐MOFs perform much better in the capture of aromatic sulfides than the original microporous MOF.

Efficient, controllable conversion of Cu(ii) to Cu(i) was realized on metal–organic frameworks by using a vapor-induced selective reduction strategy.

In order to improve the mechanical and oxygen barrier properties of poly­(butylene succinate) (PBS), two series of sugar-containing PBS copolyesters with different molecular stiffness were synthesized and comparatively investigated, in which a cyclic alditol, isosorbide (Is) or 2,3-O-isopropylidene-l-threitol (ITh) was, respectively, used as a comonomer. Both cyclic alditols were easily available from biomass feedstock, such that Is is a bicyclic compound derived from d-glucose, and ITh is a monocyclic acetalized compound coming from naturally occurring l-tartaric acid. All these copolyesters containing up to 30 mol % of sugar-based units had satisfactory number-average molecular weights in the 16 000–83 000 g mol–1 range, and presented a random microstructure together with excellent thermal stability. The sugar-containing copolyesters were all semicrystalline and still possessed the monoclinic crystal structure of PBS. The incorporation of either Is or ITh units with rigid cyclic structure into PBS chain decreased the crystallinity and crystallization rate of PBS, while it enhanced its glass transition temperature. In addition, the partial replacement of 1,4-butanediol by sugar-based units endowed PBS with steadily enhanced hydrophilicity. Depending on the type and content of sugar units, the copolyesters show different oxygen barriers and mechanical properties. It was found that copolyester with bicyclic Is sugar units exhibited a better oxygen barrier and mechanical property than that with monocyclic ITh units.