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Herein, we have specifically designed two metalated porous organic polymers (Zn‐POP and Co‐POP) for syngas (CO+H2) production from gaseous CO2. The variable H2/CO ratio of syngas with the highest efficiency was produced in water medium (without an organic hole scavenger and photosensitizer) by utilizing the basic principle of Lewis acid/base chemistry. Also, we observed the formation of entirely different major products during photocatalytic CO2 reduction and water splitting with the help of the two catalysts, where CO (145.65 μmol g−1 h−1) and H2 (434.7 μmol g−1 h−1) production were preferentially obtained over Co‐POP & Zn‐POP, respectively. The higher electron density/better Lewis basic nature of Co‐POP was investigated further using XPS, XANES, and NH3‐TPD studies, which considerably improve CO2 activation capacity. Moreover, the structure–activity relationship was confirmed via in situ DRIFTS and DFT studies, which demonstrated the formation of COOH* intermediate along with the thermodynamic feasibility of CO2 reduction over Co‐POP while water splitting occurred preferentially over Zn‐POP. [ABSTRACT FROM AUTHOR]

Herein, we have specifically designed two metalated porous organic polymers (Zn‐POP and Co‐POP) for syngas (CO+H2) production from gaseous CO2. The variable H2/CO ratio of syngas with the highest efficiency was produced in water medium (without an organic hole scavenger and photosensitizer) by utilizing the basic principle of Lewis acid/base chemistry. Also, we observed the formation of entirely different major products during photocatalytic CO2 reduction and water splitting with the help of the two catalysts, where CO (145.65 μmol g−1 h−1) and H2 (434.7 μmol g−1 h−1) production were preferentially obtained over Co‐POP & Zn‐POP, respectively. The higher electron density/better Lewis basic nature of Co‐POP was investigated further using XPS, XANES, and NH3‐TPD studies, which considerably improve CO2 activation capacity. Moreover, the structure–activity relationship was confirmed via in situ DRIFTS and DFT studies, which demonstrated the formation of COOH* intermediate along with the thermodynamic feasibility of CO2 reduction over Co‐POP while water splitting occurred preferentially over Zn‐POP. [ABSTRACT FROM AUTHOR]

Chemical warfare agents (CWAs) have been classified as fatal weapons of mass destruction because of their toxicity and deadly consequences. Among other CWAs, sulfur mustards (HDs) were employed during the Iraq–Iran war (1984–1988), causing significant fatal effects for 100 000 military and civilian Iranians, and around 45000 people are still suffering from long-term health repercussions. Hence, the detection and detoxification of these acutely dangerous chemicals are critical for protecting ourselves and have thus sparked much scientific interest around the globe. In this regard, studies show that various photoresponsive porous organic materials like activated metal–organic-frameworks (MOFs), porous organic polymers (POPs), covalent organic frameworks (COFs), and TiO2-derived materials are highly effective for the photochemical detoxification of HDs. Given this context, we have traversed through the history of developing various photoresponsive porous materials and their efficacy in detoxifying CWAs, notably HDs. Moreover, we highlighted the numerous research methodologies reported to detect and modulate the excitonic effects in photoporous materials, which can tune the in situ-generated reactive oxygen species (ROS) responsible for HD detoxification. Lastly, we have listed the hurdles in creating photoactive porous materials and functionalizing them for large-scale HD detoxification. Although most of the described porous photocatalysts demonstrated good lab-scale performance, relatively few are accessible for large-scale industrial use. We have also addressed the future needs and potential for employing photoporous materials for efficient detoxification of HDs on an industrial scale to alleviate the issue of CWA/HD stockpiling and their potential use as a weapon of mass destruction. [ABSTRACT FROM AUTHOR]

The electrochemical fixation of carbon dioxide (CO2) into organic halides is one of the most prominent strategies for mitigating atmospheric CO2 emission, along with the difficulties associated with the toxic and carcinogenic halogenated compounds. Cu-based nanomaterials have been explored for numerous applications in nanotechnology, including electrocatalysis, organic catalytic transformations, and photocatalysis. In this work, we have designed and developed a Cu-embedded carbazole-derived porous organic polymer (Cu@Cz-POP) nanohybrid by utilizing the Friedel–Crafts alkylation approach and employing 1,4-dimethoxybenzene as the cross-linking agent comprising unique characteristic features of the extended π-conjugated system along with an active metal center with tunable electrochemical properties. The Brunauer–Emmett–Teller surface area of the conjugated Cz-POP is found to be 1060 m2 g–1. The X-ray photoelectron spectroscopy (XPS) study demonstrates the formation of CuO nanoparticles in the polymeric framework. X-ray absorption fine structure analysis (EXAFS) also reveals the existence of CuO with a smaller fraction of Cu in the polymeric framework, which is corroborated with the XPS analysis. The Cu@Cz-POP nanohybrid is fabricated by drop-casting over a Ni foam, showing promising electrocatalytic activity toward electrocarboxylation of benzyl bromide in 0.1 M TBA·BF4/CH3CN with saturated CO2 medium with a current density of 120 mA cm–2 delivering 65% yield of phenylacetic acid (PAA) as the primary product along with traces of benzyl 2-phenylacetate (BPA) and 1,2-diphenylethane (DPE), and the turnover frequency is found to be 8.556 × 10–7 s–1. Density functional theory calculations demonstrate that CuO is adsorbed more favorably at the N1 nitrogen atom of Cz-POP. An electron transfer from the N1 atom and the aromatic rings of Cz-POP to the CuO center is observed and confirmed by the overlap of alpha orbitals. [ABSTRACT FROM AUTHOR]

We have introduced a Friedel–Crafts alkylation strategy of a Ni-salphen complex as derived from 2-hydroxy-5-methoxybenzaldehyde, an isomer of biomass derived vanillin, to construct a Ni-salphen based porous organic polymer (Ni@T-POP). The X-ray absorption spectroscopy (XAS) analysis revealed the existence of Ni–N2O2 core sites in the Ni@T-POP framework, which demonstrates unprecedented catalytic efficiency towards oxidative decontamination of sulfur mustards (HD's) compared to its complex precursor. [ABSTRACT FROM AUTHOR]

Herein, we have designed and synthesized two heteroatom (N, O) rich covalent organic frameworks (COF), PD‐COF and TF‐COF, respectively, to demonstrate their relative effect on CO2 adsorption capacity and also CO2/N2 selectivity. Compared to the non‐fluorinated PD‐COF (BET surface area 805 m2 g−1, total pore volume 0.3647 ccg−1), a decrease in BET surface area and also pore volume have been observed for fluorinated TF‐COF due to the incorporation of fluorine to the porous framework (BET surface area 451 m2 g−1, total pore volume 0.2978 ccg−1). This fact leads to an enormous decrease in the CO2 adsorption capacity and CO2/N2 selectivity of TF‐COF, though it shows stronger affinity towards CO2 with a Qst of 37.76 KJ/mol. The more CO2 adsorption capacity by PD‐COF can be attributed to the large specific surface area with considerable amount of micropore volume compared to the TF‐COF. Further, PD‐COF exhibited CO2/N2 selectivity of 16.8, higher than that of TF‐COF (CO2/N2 selectivity 13.4). [ABSTRACT FROM AUTHOR]

Using a catalyst-free one-pot polycondensation approach, a new donor–acceptor (D–A) based porous polyimide (PeTt–POP) photocatalyst was developed. PeTt–POP produced CH4 (125.63 ppm g−1 in 6 h) from CO2 under visible light irradiation in the gas–solid mode without the use of co-catalysts or sacrificial agents. The progress of the reaction and the corresponding intermediate species involved in the CO2 reduction were identified by operando DRIFTS experiments, from which a plausible reaction mechanism was proposed. [ABSTRACT FROM AUTHOR]

Metalated nanoporous organic polymers (M-POPs) combine covalent bonds and open metal sites to enable structural stability and single-site catalysis. In this work, we constructed two single-site Pd-metalated knitting aromatic polymers (Pd@KAP-1 and Pd@KAP-2) and explored their catalytic activity in lignocellulosic biomass-derived furfural (FFR) upgrading to tetrahydrofurfuryl alcohol (THFAL), a green industrial solvent. Pd@KAP-1 exhibits superior catalytic performance compared to Pd@KAP-2 toward FFR conversion, resulting in 80% conversion with a 95% selectivity toward THFAL. Using in situ DRIFTS analysis, we find that FFR strongly adsorbs on Pd@KAP-1, which is a key determining factor in its higher catalytic efficiency. Our X-ray photoelectron spectroscopic (XPS) measurements show a lower (∼0.3 eV) binding energy displacement of Pd-3d5/2 in Pd@KAP-1 compared to Pd@KAP-2. We attribute this to the presence of a biphenyl ring that enables partial charge transfer between the P and the Pd atoms inside the nanocavity of Pd@KAP-1 to facilitate catalytic hydrogenation. We also carried out a kinetic analysis showing that Pd@KAP-1 has a lower activation barrier than Pd@KAP-2 for the FFR hydrogenation process. Our study demonstrates a novel concept for designing efficient, robust, and sustainable metalated porous organic polymer-based heterogeneous nanocatalysts in biomass refinery industries. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate the successful construction of two Fe-metalated porous organic polymers having planar (Fe-Tt-POP) and non-planar (Fe-Rb-POP) geometry via the ternary copolymerization strategy for the catalytic oxidative decontamination of different sulfur-based mustard gas simulants (HD). Fe-Tt-POP exhibits superior catalytic performance for the oxidation of thioanisole (TA) in comparison with Fe-Rb-POP. Interestingly, this activity difference can be further explored by in situ operando DRIFTS and DFT computational studies. [ABSTRACT FROM AUTHOR]

Post-combustion CO2 capture, storage, and separation have garnered colossal research interest in the energy industry, although realistic implementation of the available porous adsorbents is restricted owing to their cost competitiveness, stability, and scalability issues. The integration of heteroatom functionalities (N, O, or S) at the molecular level into the organic skeleton of porous framework materials endowed them with superior CO2 adsorbents to mitigate greenhouse gases. In this work, we have successfully introduced triazine–thiophene (Tt) groups to the nanoporous organic polymer (POP) skeleton by Friedel–Craft alkylation of Tt (as a monomer) with a series of cross-linking agents including formaldehyde dimethyl acetal, 1,4-bis-(bromomethyl)-benzene (BMB), and 4,4′-bis-(bromomethyl)-biphenyl, which contained methylene, bis-methylene benzene, and bis-methylene biphenyl moieties in each linker unit, respectively. The precise skeleton engineering with the variation of organic cross-linking agents at the molecular level leads to the development of Tt-POP-1, Tt-POP-2, and Tt-POP-3, having nanorod-, nanocoral-, and nanocloud-like morphologies, respectively. In particular, at 273 K, Tt-POP- 1, Tt-POP- 2, and Tt-POP-3 exhibited CO2 uptake capacities of about 33.04, 40.06, and 34.12 cm3/g, respectively, up to 1 bar pressure. Interestingly, Tt-POP-2 bearing a BMB linker exhibited enhanced CO2 uptake capacity both at 298 and 273 K in comparison with the other Tt-POP-1 and Tt-POP-3, respectively. An in-depth study of the CO2 adsorption mechanism by density functional theory calculations showed that the benzyl rings of linker units in Tt-POP-2 and Tt-POP-3 play a pivotal role in CO2 uptake. The more polarized interaction of CO2 with the thiophenyl and benzyl rings compared to the N and S atoms in Tt-POP-2 results in enhanced CO2 uptake capacity with respect to the others. [ABSTRACT FROM AUTHOR]

Herein, we have reported two benzothiazole-linked covalent organic framework nanostructures (BTZ-BCA-COF and BTZ-TPA-COF), which have been prepared via a highly efficient one-pot, multicomponent transition-metal-free C–H functionalization and oxidative annulation synthetic strategy and employing elemental sulfur as one of the key components. These prepared COFs are highly crystalline in nature, have high surface area, and are chemically stable. These COFs exhibit light-harvesting capacity as a photosensitizer for visible-light-assisted "carbon–boron" bond cleavage with a high functional group tolerance of the substrates. In order to acquire in-depth understanding about the mechanistic pathway involved and for comparison in photocatalytic performance, we have performed in situ electron paramagnetic resonance and studies. Our contribution sheds light on exploration of elemental sulfur to extended π-conjugation network-based photocatalysts, followed by instigating their structural uniqueness–photocatalytic activity relationship. [ABSTRACT FROM AUTHOR]

Porous organic polymers (POPs) represent an emerging class of porous organic materials which mainly comprise organic building blocks that are interconnected via strong covalent bonds, thereby offering highly cross-linked frameworks with rigid structures and specific void spaces for accommodating guest molecules. In the past few years, POPs have garnered colossal research interest as nanoreactors for heterogeneous catalysis (thermal, photochemical, electrochemical, etc.) because of their intriguing characteristic features, such as high thermal and chemical stabilities, adjustable chemical functionalities, large surface areas, and tunable pore size distributions. This feature article provides an overview of existing research relating to diverse POP synthetic approaches (COFs, CTFs, and some amorphous POPs), the possible modification of the functionality of POPs, and their exciting application as next-generation nanoreactors. These POPs are extremely interesting, as they offer the potential for either metal-free or metalated polymer catalysts allowing photocatalytic CO2 reduction to solar-fuel, biofuel upgrades, the conversion of waste cooking oil to bio-oil, and clean H2 production from water, addressing many scientific and technological challenges and providing new opportunities for various specific topics in catalysis. Finally, we emphasize that the integration of various synthetic approaches and the application of POPs as nanoreactors will provide opportunities in the near future for the precision synthesis of functional materials with significant impact in both basic and applied research areas. [ABSTRACT FROM AUTHOR]

In this study, we adopted a cost‐effective, facile and metal & template‐free strategy for the successful synthesis of hydroxyl enriched POP (denoted as TPT). An integrated catalyst, Pd−Fe3O4@TPT, has been developed for the liquid phase selective hydrogenation cinnamaldehyde (CAL). Pd−Fe3O4@TPT exhibited excellent catalytic performance, providing 100 % selectivity towards hydrocinnamaldehyde (HCAL) under mild reaction conditions (with relatively low hydrogen pressure and very short reaction time), whereas Fe2O3@TPT appeared inert. Compared with the conventional catalytic systems, our newly designed catalyst was superior in many aspects, owing to the rigid nature of TPT‐POP, which prevents aggregation and leaching of the metal nanoparticles. [ABSTRACT FROM AUTHOR]

In this study, a Pd-based catalytic model over a nitrogen enriched fibrous Porous-Organic-Polymer (POP) is established to execute hydrodeoxygenation of various vegetable oils in producing potential large-scale renewable diesel. Here we report a cost-effective synthesis strategy for a new microporous hypercrosslinked POP through the FeCl3 assisted Friedel–Crafts alkylation reaction, followed by fabrication of Pd0-NPs (2–3 nm) using a solid gas phase hydrogenation route to deliver a novel catalytic system. This catalyst (called Pd@PPN) exhibits versatile catalytic performance for different types of vegetable oils including palm oil, soybean oil, sunflower oil and rapeseed oil to furnish long chain diesel range alkanes. The catalyst is comprehensively characterized using various spectroscopic tools and it shows high stability during five runs of recycling without leaching of Pd. Our results further reveal that a direct decarbonylation (DCN) pathway of fatty acids to produce alkanes with one fewer carbon is the dominant mechanism. Under optimized conditions, using stearic acid to represent the long linear carboxylic acids in the vegetable oils, up to 90% conversion with 83% selectivity of C17-alkane has been achieved on our fabricated catalyst. Density functional theory (DFT) calculations are performed to provide insights into the electronic properties of the catalyst, the mechanistic reaction pathway, the crucial role of the catalyst surface and the product selectivity trend. The strong interaction between the corrugated polymer-frame-structure and the Pd-NPs suggests the presence of high density step sites on the fabricated Pd-NP anchored within the cage of the polymer structure. DFT calculations also reveal the strong promotional effect of step sites and charge transfer in facilitating rate-limiting steps during the decarbonylation (DCN) pathway and removal of strongly bound intermediates formed during the process, therefore explaining the high activity of the fabricated Pd@PPN catayst for the hydrodeoxygenation (HDO) conversion to produce bio-based alkane diesel. [ABSTRACT FROM AUTHOR]

This review article encompasses the progress and conventional overview of current research activities of porous organic polymers (POPs), especially in catalysis, as they have garnered colossal interest in the scientific fraternity due to their intriguing characteristic features. Various synthetic strategies with possible modification of functionality of POPs have been used to improve the catalytic efficiency towards value‐added chemicals production. Accordingly, this review article is mainly focused on the design, development of various functionalized POPs by employing Friedel‐Crafts alkylation, FeCl3 assisted oxidative polymerisation and polymerisation in nonaqueous medium, and a comprehensive understanding in potential catalytic applications namely, acetalization, hydrodeoxygenation (HDO), hydrogenation, coupling, photocatalytic hydrogen evolution and biomass conversion towards the production of value‐added chemicals in biodiesel and chemical industries. [ABSTRACT FROM AUTHOR]

Combined noble-transition metal catalysts have been used to produce a wide range of important non-petroleum-based chemicals from biomass-derived furfural (as a platform molecule) and have garnered colossal research interest due to the urgent demand for sustainable and clean fuels. Herein, we report the palladium-modified metal–organic-framework (MOF) assisted preparation of PdCo3O4 and PdFe3O4 nanoparticles encapsulated in a graphitic N-doped carbon (NC) matrix via facile in situ thermolysis. This provides a change in selectivity with superior catalytic activity for the reductive upgrading of biomass-derived furfural (FA). Under the optimized reaction conditions, the newly designed PdCo3O4@NC catalyst exhibited highly efficient catalytic performance in the hydrogenation of furfural, providing 100% furfural conversion with 95% yield of tetrahydrofurfuryl alcohol (THFAL). In contrast, the as-synthesized Pd–Fe3O4@NC afforded a THFAL yield of 70% after an 8 h reaction with four consecutive recycling tests. Based on different characterization data (XPS, H2-TPR) for nanohybrids, we can conclude that the presence of PdCo-Nx active sites, and the multiple synergistic effects between Co3O4 and Pd(ii), Co3O4 and Pd0, as well as the presence of N in the carbonaceous matrix, are responsible for the superior catalytic activity and improved catalyst stability. Our strategy provides a facile design and synthesis process for a noble-transition metal alloy as a superior biomass refining, robust catalyst via noble metal modified MOFs as precursors. [ABSTRACT FROM AUTHOR]

Abstract: The rational design of effective and inexpensive electrocatalysts for solar‐powered water splitting is under intense focus to overcome barriers during half‐cell reactions. Towards addressing this issue, we designed and sequentially synthesized Fe2O3 and FeP nanoparticles encapsulated on a carbonaceous matrix nanoarchitecture (Fe2O3@C and FeP@C) from an Fe‐based 1,4‐benzenedicarboxylate framework (Fe‐MIL‐88B) through high‐temperature pyrolysis followed by a solid‐/gas‐phase low‐temperature phosphidation process. These nanoparticles were employed as bifunctional electrocatalysts deposited onto a Si photoelectrode assembly. The changes in morphological and electronic properties of the as‐prepared catalysts were investigated after controlled heat treatment. As‐synthesized Fe2O3@C/Si and FeP@C/Si were found to be superior bifunctional photoelectrodes in a neutral aqueous medium under simulated solar irradiation of 100 mW cm−2. Fe2O3@C/Si exhibited high activity for the oxygen evolution reaction (OER), providing a photoanodic current density of 2.5 mA cm−2 at 1.65 V (vs. RHE), which was driven by the type‐II heterojunction model in the Fe2O3@C/Si system. In parallel, the FeP@C/Si materials exhibited noticeable hydrogen evolution reaction (HER) activity, generating 10 mA cm−2 cathodic current at −0.07 V (vs. RHE). The varied performance could be attributed to the bulk size dependency of the crystalline Fe2O3 phase on the conductive sp2‐hybridized carbon framework and an intrinsic synergetic effect in the FeP@C, which originates from electronic interactions between Fe and P with high porosity, and which permits easy diffusion of the electrolyte and efficient electron transfer during hydrogen generation. [ABSTRACT FROM AUTHOR]

Development of an inexpensive, efficient and robust nanohybrid catalyst as a substitute for platinum in photoelectrocatalytic hydrogen production has been considered intriguing and challenging. In this study, the design and sequential synthesis of a novel cobalt sulfide nanoparticle grafted Porous Organic Polymer nanohybrid (CoS x@POP) is reported and used as an active and durable water-splitting photoelectrocatalyst in the hydrogen evolution reaction (HER). The specific textural and relevant chemical properties of as-synthesised nanohybrid materials (Co3O4@POP &CoS x@POP) were investigated by means of XRD, XPS, FTIR, 13C CP MAS NMR, spectroscopy, HR-TEM, HAADF-STEM with the corresponding elemental mapping, FE-SEM and nitrogen physisorption studies. CoS x@POP has been evaluated as a superior photoelectrocatalyst in HER, achieving a current density of 6.43 mA cm−2 at 0 V versus the reversible hydrogen electrode (RHE) in a 0.5 m Na2SO4 electrolyte which outperforms its Co3O4@POP analogue. It was found that the nanohybrid CoS x@POP catalyst exhibited a substantially enhanced catalytic performance of 1.07 μmol min−1cm−2, which is considered to be ca. 10 and 1.94 times higher than that of pristine POP and CoS x, respectively. Remarkable photoelectrocatalytic activity of CoS x@POP compared to Co3O4@POP toward H2 evolution could be attributed to intrinsic synergistic effect of CoS x and POP, leading to the formation of a unique CoS x@POP nanoarchitecture with high porosity, which permits easy diffusion of electrolyte and efficient electron transfer from POP to CoS x during hydrogen generation with a tunable bandgap, that straddles between the reduction and oxidation potential of water. [ABSTRACT FROM AUTHOR]

Robust nanoarchitectures based on surfactant-free ultrafine Pd nanoparticles (NPs) (2.7-8.2±0.5 nm) have been developed by using the incipient wetness impregnation method with subsequent reduction of PdII species encaged in the 1,3,5-triazine-functionalized nitrogen-rich porous organic polymer (POP) by employing NaBH4, HCHO, and H2 reduction routes. The Pd-POP materials prepared by the three different synthetic methods consist of virtually identical chemical compositions but have different physical and texture properties. Strong metal-support interactions, the nanoconfinement effect of POP, and the homogeneous distribution of Pd NPs have been investigated by performing 13C cross-polarization (CP) solid-state magic angle spinning (MAS) NMR, FTIR, and X-ray photoelectron spectroscopy (XPS), along with wide-angle powder XRD, N2 physisorption, high-resolution (HR)-TEM, high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), and energy-dispersive X-ray (EDX) mapping spectroscopic studies. The resulting Pd-POP based materials exhibit highly efficient catalytic performance with superior stability in promoting biomass refining (hydrodeoxygenation of vanillin, a typical compound of lignin-derived bio-oil). Outstanding catalytic performance (≈98 % conversion of vanillin with exclusive selectivity for hydrogenolysis product 2-methoxy-4-methylphenol) has been achieved over the newly designed Pd-POP catalyst under the optimized reaction conditions (140 °C, 10 bar H2 pressure), affording a turnover frequency (TOF) value of 8.51 h−1 and no significant drop in catalytic activity with desired product selectivity has been noticed for ten successive catalytic cycles, demonstrating the excellent stability and reproducibility of this catalyst system. A size- and location-dependent catalytic performance for the Pd NPs with small size (1.31±0.36 and 2.71±0.25 nm) has been investigated in vanillin hydrodeoxygenation reaction with our newly designed Pd-POP catalysts. The presence of well-dispersed electron-rich metallic Pd sites and highly rigid cross-linked amine-functionalized POP framework with high surface area is thought to be responsible for the high catalytic activity and improvement in catalyst stability. [ABSTRACT FROM AUTHOR]

The uncoordinated sulfur atom of the thiocyanato ligand of a 3D metallo-organic framework (MOF), [Ni(3-bpd)2(NCS)2]n (1), where 3-bpd is 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene, has been explored for selective visual detection and effective removal of Hg2+ in aqueous medium. [Ni(3-bpd)2(NCS)2]n has been synthesized under ambient conditions and characterized by elemental analysis, FT-IR spectroscopy, UV-vis spectroscopy, FE-SEM and EDX, XPS and X-ray single crystal diffraction analysis. 1 shows two thiocyanato moieties bound to the hexacoordinated metal center with N atoms whereas the sulfur end remains uncoordinated. The strategy for binding and removal of Hg2+ is very simple. Hg2+ is known for its affinity for strong bond formation with the soft center, S. The sulfur atoms form bonds with this heavy metal ion. The color of 1 changes from green to grey as Hg atoms form coordinate bonds with S atoms of the SCN− group. It has been found that Hg is present in grey materials in a 2 : 1 ratio (Hg/Ni). 1 is selective for Hg as other metals/metalloids, including heavy metal ions, present in water are unable to change the color of 1 as they do not form any bond with it. Binding of Hg with the S end of the thiocyanato moiety has been confirmed by a number of techniques, e.g. IR and UV-vis spectra, FESEM, EDX, and XPS. Simple filtration is done to separate grey materials for the removal of Hg2+ ion from the water medium. A theoretical calculation has been performed to rationalize the fact. [ABSTRACT FROM AUTHOR]

A novel MnFe2O4-porous organic polymer (POP) nanocomposite was synthesized by a facile hydrothermal method and using the highly cross-linked N-rich benzene-benzylamine POP. The nanocomposite presented highly efficient photocatalytic performance in the hydrogen evolution reaction (HER) from pure water without addition of any sacrificial agent under one AM 1.5 G sunlight illumination. A photocatalytic activity of 6.12 mmol h−1 g−1 was achieved in the absence of any noble metal cocatalyst, which is the highest H2 production rate reported for nonprecious metal catalysts. The photocatalytic performance of MnFe2O4-POP could be attributed to the intrinsic synergistic effects of manganese ferrite (MnFe2O4) nanoclusters interacting with the nitrogen dopant POP with a unique mesoporous nanoarchitecture and spatially confined growth of MnFe2O4 in the interconnected POP network, leading to high visible-light absorption with fast electron transport. [ABSTRACT FROM AUTHOR]

A novel strategy has been adopted for the construction of a copolymer of benzene-benzylamine-1 (BBA-1), which is a porous organic polymer (POP) with a high BET surface area, through Friedel-Crafts alkylation of benzyl-amine and benzene by using formaldehyde dimethyl acetal as a cross-linker and anhydrous FeCl3 as a promoter. Ruthenium nanoparticles (Ru NPs) were successfully distributed in the interior cavities of polymers through NaBH4, ethylene glycol, and hydrothermal reduction routes, which delivered Ru-A, Ru-B, and Ru-C materials, respectively, and avoided aggregation of metal NPs. Homogeneous dispersion, the nano-confinement effect of the polymer, and the oxidation state of Ru NPs were verified by employing TEM, energy-dispersive X-ray spectroscopy mapping, cross polarization magic-angle spinning 13C NMR spectroscopy, and X-ray photoelectron spectroscopy analytical tools. These three new Ru-based POP materials exhibited excellent catalytic performance in the hydrogenation of nitroarenes at RT (with a reaction time of only 30 min), with high conversion, selectivity, stability, and recyclability for several catalytic cycles, compared with other traditional materials, such as Ru@C, Ru@SiO2, and Ru@TiO2, but no clear agglomeration or loss of catalytic activity was observed. The high catalytic performance of the ruthenium-based POP materials is due to the synergetic effect of nanoconfinement and electron donation offered by the 3D POP network. DFT calculations showed that hydrogenation of nitrobenzene over the Ru (0001) catalyst surface through a direct reaction pathway is more favorable than that through an indirect reaction pathway. [ABSTRACT FROM AUTHOR]

Sustainable supply of energy is one of the biggest challenges today. The conversion of energy from any abundant and renewable resources would be an ideal solution for this ever increasing demand of sustainable energy. Biomass provides a potential energy alternative through the platform chemical 5-hydroxymethylfurfural (HMF), which is considered as a sustainable source for liquid fuels and commodity chemicals. Herein, we report the synthesis of a nanoporous polytriphenylamine (PPTPA-1) having high surface area (1437 m2 g−1) by a simple one-step oxidative polymerization pathway. Upon sulfonation of PPTPA-1, the sulfonated polymer SPPTPA-1 showed very high surface acidity and it has been successfully employed as a solid acid catalyst for direct conversion of sugar to HMF. Both PPTPA-1 and SPPTPA-1 materials have distinct nanofiber morphologies and they are characterized thoroughly by using powder XRD, FTIR spectroscopy, 13C solid state magic-angle-spinning NMR spectrometry, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, and N2 sorption techniques. We have optimized the HMF yields by using different carbohydrate sources and estimated the recycling efficiency of the catalyst. [ABSTRACT FROM AUTHOR]

Correction for 'Metal–organic-framework derived Co–Pd bond is preferred over Fe–Pd for reductive upgrading of furfural to tetrahydrofurfuryl alcohol' by Saikiran Pendem et al., Dalton Trans., 2019, 48, 8791–8802, https://doi.org/10.1039/C9DT01190K. [ABSTRACT FROM AUTHOR]

A versatile heterogeneous photocatalysis protocol was developed by using ruthenium bipyridyl tethered porous organosilica (Ru-POS). The versatility of the Ru-POS catalyst in organo-photocatalysis was explored by (i) oxidative aromatization of Hantzsch ester, (ii) reductive dehalogenation of alkyl halides, and (iii) functional group interconversion (FGI) of alcohols to alkyl halides. [ABSTRACT FROM AUTHOR]

Mn3O4 nanomaterials with different morphologies (sphere, nanowire, and octahedron) embedded into functionalized nanoporous polymers were developed by a facile one-pot solvothermal technique at different temperatures. These Mn3O4-based hybrid materials could behave as heterogeneous nanocatalysts to perform sp3 CH bond oxidation of aromatic hydrocarbons and alcohols with molecular oxygen as an economic oxidant. Catalytic activity could be effectively tuned by changing the morphology of incorporated Mn3O4 in nanoporous polymer. These Mn3O4-based hybrid materials exhibited remarkable catalytic performance for sp3 CH bond oxidation as compared with bare Mn3O4 nanoparticles. Mn3O4 with octahedral morphology in nanoporous polymer exhibited the highest catalytic activity on account of its more exposed crystallographic planes and edges. These Mn3O4-based nanocatalysts could be recycled and reused for consecutive catalytic cycles without a significant loss of catalytic activity. [ABSTRACT FROM AUTHOR]

A new highly ordered mesoporous tungstic acid functionalized SBA-15, TAFMC-1 has been synthesized via post-synthesis modification of mesoporous SBA-15 with (3-chloropropyl) triethoxysilane followed by substitution reaction of chlorine atom of the 3-chloropropyl group by tungstic acid group under refluxing conditions in n-hexane. The tungstic acid functionalized mesoporous silica material has been characterized by using small angle powder X-ray diffraction, N2 sorption, HR-TEM, FE-SEM, FT-IR and solid state MAS NMR studies. TAFMC-1 catalyzes the facile one-pot catalytic three-component condensation reaction of resorcinol, aromatic aldehyde and malononitrile for the synthesis of a diverse range of 2-amino-4H-chromenes in aqueous medium. This heterogeneous catalyst can be recycled very efficiently for six consecutive reaction cycles without significant loss of catalytic activity. [ABSTRACT FROM AUTHOR]

Rich in more ways than one: High surface area ‐CO2H rich organic polymer have been designed, which acts as an excellent carbocatalyst in a series of indole 3‐substitution reactions at room temperature. [ABSTRACT FROM AUTHOR]

For the first time, we have used activated alumina balls (3–5 mm diameter) for amide synthesis from carboxylic acids (unactivated) and amines (unactivated) under neat reaction conditions that produce no toxic by-products and has the advantages of being low-cost, easily available, heterogeneous, reusable and environmentally benign with no troublesome/hazardous disposal of the catalyst. [ABSTRACT FROM AUTHOR]

A new organic-inorganic hybrid porous iron-phosphonate material, HPFP-1, has been synthesized under hydrothermal conditions by using hexamethylenediamine- N, N, N′, N′-tetrakis-(methylphosphonic acid) (HDTMP) as the organophosphorus precursor. The morphology of this material was found to be different at three different temperatures. The material that was synthesized at 453 K showed a flake-like particle morphology and the material was highly crystalline. Whereas, the materials that were synthesized at 443 K and 423 K were semi-crystalline and showed rod-like- and spherical morphological features, respectively. SEM and TEM were employed to understand this change in particle morphology depending on the reaction temperature. Powder XRD analysis suggested the formation of a new tetragonal phase in HPFP-1 ( a=11.313, c=15.825 Å; V=2025.659 Å3). N2-sorption analysis suggested the existence of supermicropores and interparticle mesopores in these materials. Elemental- and thermal analyses, as well as FTIR spectroscopy, were employed to verify the composition and framework bonding of the material. The HPFP-1 material showed excellent catalytic activity for the synthesis of benzimidazole derivatives under mild liquid-phase reaction conditions. [ABSTRACT FROM AUTHOR]

The high surface area of 2D-hexagonal periodic mesoporous organosilica (PMO) containing a phloroglucinol-diimine moiety inside the pore wall has been utilized for grafting Pd(ii) at the surface of the mesopores. This Pd-containing PMO material (Pd-LHMS-3) shows excellent catalytic activity in fluoride-free Hiyama cross-coupling reactions in water at alkaline pH conditions. Sonogashira cross-couplings between terminal alkynes and aryl halides take place in the presence of water and hexamine as base in the absence of any Cu co-catalyst. Cyanation of aryl halides is equally promoted with K4[Fe(CN)6] as the cyanide source (in the absence of poisonous KCN, NaCN or Zn(CN)2) over Pd-LHMS-3. Excellent yield of the products, reusability and the facile work-up could make this Pd-grafted PMO material a unique catalyst for the synthesis of substituted benzonitriles, unsymmetrical biphenyls and di-substituted alkynes under environmentally benign reaction conditions. Further good yield of products and no evidence of leached Pd from the catalyst surface during the reaction and its smooth recovery confirm the true heterogeneity in these catalytic reactions. [ABSTRACT FROM AUTHOR]

A new functionalized mesoporous polymer (MPTAT-1) has been synthesized viaorganic–organic radical polymerization of 2,4,6-triallyloxy-1,3,5-triazine (TAT) in aqueous medium in the presence of an anionic surfactant (sodium dodecyl sulfate) as template. Powder XRD and TEM image analysis suggests the presence of ordered 2D-hexagonal arrangement of pores in the material. N2sorption analysis reveals a moderately good surface area 135 m2g−1for this mesoporous polymer. The template free MPTAT-1 acts as an excellent support for immobilizing Pd(ii) at its surface and the resulting material showed very good catalytic activity in several C–C cross-coupling reactions like Mizoroki–Heck, Sonogashira and Suzuki–Miyaura in an environmentally benign reaction medium, water. The catalyst exhibits very high catalytic activity for the coupling of various aryl halides including aryl chlorides with alkenes or alkynes and the sodium salt of (trihydroxy)phenylborate. Due to strong binding with the functional groups of the polymer, the anchored Pd(ii) could not leach out from the surface of the mesoporous catalyst during the reaction and it has been reused several times without appreciable loss in catalytic activity. [ABSTRACT FROM AUTHOR]

A new functionalized mesoporous polymer (MPTAT-1) has been synthesized via organic–organic radical polymerization of 2,4,6-triallyloxy-1,3,5-triazine (TAT) in aqueous medium in the presence of an anionic surfactant (sodium dodecyl sulfate) as template. Powder XRD and TEM image analysis suggests the presence of ordered 2D-hexagonal arrangement of pores in the material. N2 sorption analysis reveals a moderately good surface area 135 m2 g−1 for this mesoporous polymer. The template free MPTAT-1 acts as an excellent support for immobilizing Pd(ii) at its surface and the resulting material showed very good catalytic activity in several C–C cross-coupling reactions like Mizoroki–Heck, Sonogashira and Suzuki–Miyaura in an environmentally benign reaction medium, water. The catalyst exhibits very high catalytic activity for the coupling of various aryl halides including aryl chlorides with alkenes or alkynes and the sodium salt of (trihydroxy)phenylborate. Due to strong binding with the functional groups of the polymer, the anchored Pd(ii) could not leach out from the surface of the mesoporous catalyst during the reaction and it has been reused several times without appreciable loss in catalytic activity. [ABSTRACT FROM AUTHOR]

A new organosilane precursor has been designed viaVilsmeier–Haack formylation of phloroglucinol followed by its Schiff base condensation with 3-aminopropyl-triethoxysilane (APTES). A novel organic–inorganic hybrid periodic mesoporous organosilica (PMO) LHMS-3 containing the highly coordinating bis(propyliminomethyl)-phloroglucinol moiety inside the pore wall has been synthesized by using this precursor organosilane molecule. Phenolic-OH and imine-N donor sites present in this PMO material have been utilized to anchor Pd(ii) species at the surface of the mesopores. Small angle neutron scattering, XRD, HR TEM, SEM, 13C and 29Si solid state MAS NMR, UV-vis and FT IR spectroscopic tools are utilized to characterize the 2D-hexagonal mesophase and the presence of the bis(propyliminomethyl)-phloroglucinol moiety inside the pore wall. This Pd-anchored material Pd-LHMS-3 showed excellent catalytic activity and trans-selectivity in Heck C–C bond formation reactions for the synthesis of a series of value-added aromatic and aliphatic olefins. [ABSTRACT FROM AUTHOR]

Magnetic Fe3O4 nanoparticles embedded in graphene oxide (Fe3O4@GO) behave as a highly efficient and reusable heterogeneous nanocatalyst for alkene hydrogenation in EtOH at 80 °C temperature using hydrazine hydrate as the hydrogen source to deliver the corresponding alkanes in good to excellent yields together with high TOF (44500 h-1) within a 4-20 h reaction time. [ABSTRACT FROM AUTHOR]

Cu0 nanoparticles were deposited on a nanoporous polymer to develop a novel nanocatalyst (Cu-B) for carrying out Ullmann coupling of aryl halides with amines in water. Non-aqueous polymerization of a mixture of divinylbenzene and acrylic acid under hydrothermal conditions followed by the deposition of Cu0 nanoparticles were adopted to afford the Cu-B nanocatalyst. In order to compare the catalytic activity of the Cu-B nanocatalyst in the Ullmann coupling reactions, another nanocatalyst, Cu0 nanoparticle-loaded porous carbon (Cu-A), was also prepared. All the newly developed Cu0 nanoparticle-based nanocatalysts were thoroughly characterized using several characterization techniques. The Ullmann coupling reactions were carried out in water only with 1.35 mol% loading of Cu as catalytically active sites in Cu-B. The Cu-B nanocatalyst exhibited higher catalytic activity as compared with Cu-A, and also showed a good catalytic recyclability with a high consistence in the catalytic activity. No Cu leaching from the nanocatalyst surface and the smooth nanocatalyst recovery confirm the true heterogeneity in these catalytic reactions. [ABSTRACT FROM AUTHOR]