The use and transformation of carbon dioxide as a C1 source into valuable chemical products using cheap industrial chemicals under mild reaction conditions fulfill the requirements of atom economy in the chemical industry. In this paper, two new silver-cluster-based frameworks were synthesized by incorporating thiourea on the backbone of the tripodal ligands. Given their large pores, high density of catalytic sites, and appropriate coordination geometries, these heterogeneous materials could be used as high-efficiency π-activation catalysts in the atom-economical cycloaddition of propargylamines with carbon dioxide. The loading of 0.1 mol % catalysts enabled the almost complete transformation of the propargylamines into oxazolidinones at atmospheric pressure and room temperature. DFT calculations show significant charge accumulation regions with π* symmetry on C atoms associated with the acetylene bond along the Ag−C directions and charge depletion regions with σ symmetry along the C−C direction, further supporting the important role of silver-cluster-based catalysts in π* activation of substrates for subsequent reactions with approaching CO 2 . The crystallinity of the frameworks allowed the structure of the encapsulated substrates and the interactions of the CC bonds in the active intermediates to be clearly observed. The recyclability and high turnover number of the cycloaddition reaction demonstrate the broad potential applications of these designed materials as πactivation catalysts for practical applications in the chemical industry.

The design of artificial systems that mimic highly evolved and finely tuned natural enzymes is a promising subject of intensive research. The assembly of O-symmetric cubic structures with an Fe L formula was reported through the direct combination of a C -symmetric tetraphenylethylene-based ligand with a C -symmetric tris(bipyridine)iron node. The robust metal-organic cubes are rich in π-electron density and provide favorable interactions with planar polycyclic aromatic hydrocarbons. Within the confined space of the host, the aromatic hydrocarbons molecules are forced closer to the redox active host, and the photoinduced electron transfer (PET) is modified into a pseudo-intramolecular pathway. These iron vertices within the cubes exhibit suitable redox potential for electrochemical reduction of protons and the well-modified PET is further tailored to create artificial systems for light-driven hydrogen evolution from water through the encapsulation of fluorescein dyes. Control experiments based on a mononuclear compound resembling the iron corner of the octahedron suggest an enzymatic dynamic behavior. The new, well-elucidated reaction pathways and the increased molarity of the reaction within the confined space render these supramolecular systems superior to other relevant systems.

Solar production of hydrogen by consuming low-value waste products is an attractive pathway that has both economic and environmental benefits. Inspired by the reactive pocket of enzymes, a synthetic platform to combine photocatalytic hydrogen evolution with sulfide oxidation in a one-pot process via control over the location of the electron-transfer steps is developed. The redox-active coordination vessel Ni-TFT, which has an octahedral pocket, encapsulates an organic dye to pre-organize for photocatalytic proton reduction via an oxidative quenching pathway using the nickel corners as catalysts, generating molecular hydrogen and the oxidized dye. The oxidized dye is displaced by a neutral dye and oxidizes sulfide once outside the pocket to give element sulfur. The overall reaction constitutes hydrogen sulfide splitting, forming molecular hydrogen and elemental sulfur, which is analogous to the water-splitting reaction.

A thiourea-based metal–organic framework with open Ag+ sites for the separation of a C3H6/C3H8 mixture.

As common coinage metals, silver and silver compounds have very rich application in the organic catalytic reaction. Immobilization of silver compounds on heterogeneous media is the most common way used in industrial catalytic reactions. In this work, we designed and synthesized a new heterogeneous porous silver catalyst, with in situ-formed Ag–S rods as connecting nodes and thiosemicarbazide-functionalized linear ligands, used in both σ- and π-catalytic transformations. Strong Ag–S bonds bypassed the loss of noble silver elements and inhibited the formation of nonporous silver particles which always led to the decrease of yields in homogenous reactions. Furthermore, various derivatives of propargylamines and phenylacetylenes were applied as both σ and π-active substrates with moderate to good yields.

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Solar production of hydrogen by consuming lowvalue waste products is an attractive pathway that has both economic and environmental benefits.Inspired by the reactive pocket of enzymes,asynthetic platform to combine photocatalytic hydrogen evolution with sulfide oxidation in aone-pot process via control over the location of the electron-transfer steps is developed. The redox-active coordination vessel Ni-TFT,which has an octahedral pocket, encapsulates an organic dye to pre-organizefor photocatalytic proton reduction via an oxidative quenching pathway using the nickel corners as catalysts,generating molecular hydrogen and the oxidized dye. The oxidized dye is displaced by an eutral dye and oxidizes sulfide once outside the pocket to give element sulfur.T he overall reaction constitutes hydrogen sulfide splitting,forming molecular hydrogen and elemental sulfur,w hich is analogous to the water-splitting reaction.