Network Approaches to Highly Porous Materials: Metal-organic frameworks (MOFs), in which inorganic centers are bridged by organic linkers, can achieve very high porosity for gas absorption. However, as the materials develop larger void spaces, there is also more room for growing interpenetrating networks—filling the open spaces not with gas molecules but with more MOFs. Furukawa et al. (p. 424 , published online 1 July) describe the synthesis of a MOF in which zinc centers are bridged with long, highly conjugated organic linkers, but in which the overall symmetry of the networks created prevents formation of interpenetrating networks. Extremely high surface areas and storage capacities for hydrogen, carbon dioxide, and methane were observed.

Ni nanoparticles embedded in the pores of a mesoporous MOF (MesMOF-1) act as a catalyst for hydrogenolysis of nitrobenzene or hydrogenation of styrene.

MIL-101 and MIL-101–NH₂ were partially modified to incorporate various functional groups that are capable of forming hydrogen bonds with water. Specifically, MIL-101–NH₂ was partially functionalized with –NHCONHCH₂CH₃ (–UR2), –NHCOCHCHCOOH (–Mal), or –NH(CH₂)₃SO₃H (–3SO₃H) and MIL-101 was partially functionalized with –COOH in order to investigate the effect of these groups on the water sorption properties when compared to the pristine versions. The MIL-101 derivatives were synthesized by either post-synthetic modification of MIL-101–NH₂ or through direct synthesis using a mixed linker strategy. The ratios of the incorporated functional groups were determined by ¹H-NMR analyses and the porosity changes were revealed by N₂ gas adsorption measurements at 77 K. Water sorption isotherms at 298 K conclude that the incorporation of –3SO₃H enhances the water vapour uptake capacity at a low relative pressure (P/P₀ = 0.30), whereas –UR2 and –Mal retard water adsorption in MIL-101–NH₂. The partial incorporation of –COOH in MIL-101 exhibits a steeper water uptake at lower pressure (P/P₀ = 0.40) than MIL-101–NH₂. Interestingly, a greater –COOH content within the MIL-101 framework reduces the water uptake capacity. These results indicate that even partial functionalization of MIL-101 induces noticeably large changes in the water adsorption properties.