Frustrated Lewis pairs (FLPs) consist of sterically hindered Lewis acids and Lewis bases, which provide high catalytic activity towards non‐metal‐mediated activation of “inert” small molecules, including CO2 among others. One critical issue of homogeneous FLPs, however, is their instability upon recycling, leading to catalytic deactivation. Herein, we provide a solution to this issue by incorporating a bulky Lewis acid‐functionalized ligand into a water‐tolerant metal‐organic framework (MOF), named SION‐105, and employing Lewis basic diamine substrates for the in situ formation of FLPs within the MOF. Using CO2 as a C1‐feedstock, this combination allows for the efficient transformation of a variety of diamine substrates into benzimidazoles. SION‐105 can be easily recycled by washing with MeOH and reused multiple times without losing its identity and catalytic activity, highlighting the advantage of the MOF approach in FLP chemistry.

Prolonged consumption of water contaminated with fluoride ions (F − ) at concentrations exceeding 1.5 ppm can lead to considerable health implications, particularly in children and developing embryos. With irreversible and potentially severe forms of fluoride (F − ) toxicity such as skeletal fluorosis being endemic in at least 25 countries, constructing affordable, remoteaccess, reliable water-sampling methods for F − contamination is an important goal. In this work, we present a novel lanthanide-based luminescent metal−organic framework, named SION-105, with a boron (B) receptor site whose interactions with F − in aqueous solutions are simultaneously electrostatic and specific in nature because of its carefully designed structural environment. This allows the material to be easily regenerated and used over 10 cycles, setting it apart from most existing molecular and polymeric F − sensors. SION-105 has been combined with a portable prototype sampling device that was designed and built in-house to measure F − concentrations in natural groundwater samples taken from three different countries, with the results showing excellent agreement with ion chromatography analysis.

We demonstrate the use of an in situ formed frustrated Lewis pair within MOF-545 to effectively hydrogenate CO2 to methoxide at a low temperature and pressure.

Electrochemical reduction of carbon dioxide (CO2RR) is promoted by ionic liquid (IL) co-catalysts, and several mechanisms have been proposed to explain their role. Due to the complexity of the CO2RR and the limited number of active IL co-catalysts, a consensus on the precise role of ILs has not been reached, and it is not possible to improve their activity in a rational way. Herein, we describe guanidinium (Gua) ILs that act as co-catalysts for the CO2RR when employed in non-aqueous electrolytes. The peripheral substituents of the Gua cation were systematically modified allowing the IL co-catalytic properties to be fine-tuned, and on the basis of the observed substitution effects, charge delocalization and availability were shown to be the critical descriptors determining co-catalytic activity. These descriptors can be used to rationalize activity trends for other classes of IL co-catalysts.

Methanation of carbon dioxide (CO2) is attractive within the context of a renewable energy refinery. Herein, we report an indirect methanation method that harnesses amino alcohols as relay molecules in combination with a catalyst comprising ruthenium nanoparticles (NPs) immobilized on a Lewis acidic and robust metal–organic framework (MOF). The Ru NPs are well dispersed on the surface of the MOF crystals and have a narrow size distribution. The catalyst efficiently transforms amino alcohols to oxazolidinones (upon reaction with CO2) and then to methane (upon reaction with hydrogen), simultaneously regenerating the amino alcohol relay molecule. This protocol provides a sustainable, indirect way for CO2 methanation as the process can be repeated multiple times.

Frustrated Lewis pairs (FLPs) consist of sterically hindered Lewis acids and Lewis bases,w hichp rovide high catalytic activity towards non-metal-mediated activation of "inert" small molecules,i ncluding CO 2 among others.O ne critical issue of homogeneous FLPs,h owever,i st heir instability upon recycling,leading to catalytic deactivation. Herein, we provide as olution to this issue by incorporating ab ulky Lewis acid-functionalized ligand into aw ater-tolerant metalorganic framework (MOF), named SION-105,and employing Lewis basic diamine substrates for the in situ formation of FLPs within the MOF.U sing CO 2 as aC 1-feedstock, this combination allows for the efficient transformation of avariety of diamine substrates into benzimidazoles. SION-105 can be easily recycled by washing with MeOH and reused multiple times without losing its identity and catalytic activity,h ighlighting the advantage of the MOF approach in FLP chemistry.During the last decade,intensive efforts have been devoted to tackle the enormous emissions of CO 2 into the atmosphere; these include the development and promotion of renewable energy sources,i mprovements in energy efficiency, the reduction of carbon emissions,t he development of efficient carbon capture and storage technologies,a nd the transformation of the emitted CO 2 into valuable products. [1,2] To date,t he last approach has attracted al ot of attention, since using CO 2 feedstocks could help to close the carbon cycle and reduce petrochemical consumption. Thec hallenge,h owever, is that CO 2 is arelatively unreactive molecule. [3] In recent years,frustrated Lewis pairs (FLPs), comprising Lewis acids and bases sterically hindered in such aw ay that the acid-base adduct is not formed as in classical Lewis pairs, exhibit outstanding ability for CO 2 non-metal-mediated activation due to their unquenched reactivity. [4][5][6][7] One of the challenges of FLP chemistry,i st heir high sensitivity towards moisture,a lthough recent studies showed that careful tuning of the steric environment of the acidic center, as well as regulation of basicity of the basic center, affords moisturetolerant systems. [8][9][10] Indeed, the current research tendency toward FLPs already shifts from the early proof-of-concept investigations to practical applications,with FLPs being facile and powerful tools in chemical conversion. [9,[11][12][13] FLPs have been found to be applicable for the conversion of CO 2 to CO, methanol, methane,a nd formamides among others. [14][15][16] Moreover,C O 2 can be used as aC 1-building block for the synthesis of more complicated value-added products,such as the conversion of o-phenylenediamine and CO 2 into benzimidazole using silanes as reducing agents,w hich proceeds through an FLP-mediated pathway,w ith B(C 6 F 5 ) 3 as ac atalyst. [17] It is worth noting that the majority of industrial chemical processes deploy heterogeneous catalytic systems,a st he comparative stability and facile separation of the products from the catalyst facilitates scale-up and continuous product...

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Dedicated to Professor Rinaldo Poli on the occasion of his 65th birthday.We describe the use of CO 2 as a promising C1 source instead of CO in the tandem Pauson-Khand reaction. The reaction is achieved by combining the reduction of CO 2 to CO using a metal organic framework (MOF) catalyst with homogeneous rhodium catalysts for the cycloaddition step. A range of substrates were converted in moderate to good yields.