Light‐harvesting MOFs: A new porous porphyrinic metal–organic framework (MOF; see picture) was obtained by hydrothermal synthesis. The chemical and thermal stability of the material allows a postsynthetic insertion of zinc in the center of the porphyrin. The visible‐light photocatalytic activity of this porphyrin‐based material is shown for the sacrificial hydrogen evolution from water.

Porous materials find widespread application in storage, separation, and catalytic technologies. We report a crystalline porous solid with adaptable porosity, in which a simple dipeptide linker is arranged in a regular array by coordination to metal centers. Experiments reinforced by molecular dynamics simulations showed that low-energy torsions and displacements of the peptides enabled the available pore volume to evolve smoothly from zero as the guest loading increased. The observed cooperative feedback in sorption isotherms resembled the response of proteins undergoing conformational selection, suggesting an energy landscape similar to that required for protein folding. The flexible peptide linker was shown to play the pivotal role in changing the pore conformation

Two-dimensional (2D) solid-state nuclear magnetic resonance (SSNMR) experiments on samples loaded with C-labeled CO, "under controlled partial pressures", have been performed in this work, revealing unprecedented structural details about the formation of CO adducts from its reaction with various amine-functionalized SBA-15 containing amines having distinct steric hindrances (e.g., primary, secondary) and similar loadings. Three chemisorbed CO species were identified by NMR from distinct carbonyl environments resonating at δ ≈ 153, 160, and 164 ppm. The newly reported chemisorbed CO species at δ ≈ 153 ppm was found to be extremely moisture dependent. A comprehensive H-based SSNMR study [1DH and 2D H-X heteronuclear correlation (HETCOR, X =C, Si) experiments] was performed on samples subjected to different treatments. It was found that all chemisorbed CO species are involved in hydrogen bonds (HBs) with either surface silanols or neighboring alkylamines. H chemical shifts up to 11.8 ppm revealed that certain chemisorbed CO species are engaged in very strong HBs. We effectively demonstrate that NMR may help in discriminating among free and hydrogen-bonded functional groups. C{N} dipolar-recoupling NMR showed that the formation of carbonate or bicarbonate is excluded. Density functional theory calculations on models of alkylamines grafted into the silica surface assisted the H/C assignments and validated various HB arrangements that may occur upon formation of carbamic acid. This work extends the understanding of the chemisorbed CO structures that are formed upon bonding of CO with surface amines and readily released from the surface by pressure swing.

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Porous materials are attractive for separation and catalysis-these applications rely on selective interactions between host materials and guests. In metal-organic frameworks (MOFs), these interactions can be controlled through a flexible structural response to the presence of guests. Here we report a MOF that consists of glycyl-serine dipeptides coordinated to metal centres, and has a structure that evolves from a solvated porous state to a desolvated non-porous state as a result of ordered cooperative, displacive and conformational changes of the peptide. This behaviour is driven by hydrogen bonding that involves the side-chain hydroxyl groups of the serine. A similar cooperative closure (reminiscent of the folding of proteins) is also displayed with multipeptide solid solutions. For these, the combination of different sequences of amino acids controls the framework's response to the presence of guests in a nonlinear way. This functional control can be compared to the effect of single-point mutations in proteins, in which exchange of single amino acids can radically alter structure and function.