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Selective synthesis of higher oxygenates from syngas is an important but challenging research target, and the present methods for converting syngas into oxygenates suffer from low selectivity and h...

In contrast to heterogeneous network frameworks (e.g., covalent organic frameworks and metal-organic frameworks) and porous organic polymers, porous organic cages (POCs) are soluble molecules in common organic solvents that provide significant potential for homogeneous catalysis. Herein, we report a triphenylphosphine-derived quasi-porous organic cage (denoted as POC-DICP) as an efficient organic molecular cage ligand for Rh/PPh3 system-catalyzed homogeneous hydroformylation reactions. POC-DICP not only displays enhanced hydroformylation selectivity (aldehyde selectivity as high as 97% and a linear-to-branch ratio as high as 1.89) but can also be recovered and reused via a simple precipitation method in homogeneous reaction systems. We speculate that the reason for the high activity and good selectivity is the favorable geometry (cone angle = 123.88°) and electronic effect (P site is relatively electron-deficient) of POC-DICP, which were also demonstrated by density functional theory calculations and X-ray absorption fine-structure characterization.

Three trivinyl functionalization triphenylphosphine (3vPPh3)-based porous organic ligands (3vPPh3-POLs) with cross-linkers in different positions were obtained through solvothermal polymerization. By simply changing the position of the cross-linkers (vinyl groups) attached to the PPh3 monomer, the resulting porous organic polymer (POP) materials acquired diverse hierarchical porous structures, and the microenvironment of POPs was sequently regulated. Among the three 3vPPh3-POLs, the BET surface areas ranged from 168 to 1583 m2 g−1, while the proportion of micropores changed from 0.0% to 52.0%. Benefiting from the unique structure, Rh ions could be coordinated and dispersed as a single site in m-3vPPh3-POL to form HRh(CO)2(PPh3-POL)2 species, which endowed the Rh/m-3vPPh3-POL catalyst with an activity similar to that in the homogeneous system, an l/b ratio (the ratio of the linear aldehyde to the branched aldehyde) approximately as high as 10, and stability for a duration of more than 500 h in the hydroformylation of 1-octene.

CO2 as a C1 building block for the N-formylation reaction is attracting much attention. In general, the N-formylation reaction requires the participation of alkali, which can break the equilibrium ...

Utilization of CO2 for the production of fine chemicals has become a research hotspot for a long time. In order to make use of CO2, we developed a highly efficient heterogeneous catalyst (denoted as Pd@POPs) for the N-formylation reaction of amine and CO2 under mild conditions. The Pd catalyst was based on a porous organic polymer derived from the solvothermal polymerization of vinyl-functionalized PPh3. A series of characterizations and comparative experiments demonstrated that the Pd@POPs catalyst has high BET (Brunauer-Emmett-Teller) surface areas, hierarchical pore structure, and uniform dispersion of Pd active sites resulting from the formation of strong coordination bonds between Pd species and P atoms in the porous organic polymer (POP) support. In addition to the excellent activity, the Pd@POPs catalyst shows good stability for the N-formylation reaction of amine and CO2.

Formic acid (FA) has attracted extensive attention as a hydrogen storage material. Here, we develop two heterogeneous catalysts based on porous organic polymers (POPs). After loading the Ru species, the catalyst bearing the triphenylphosphine ligand showed excellent performance in terms of activity and stability for the decomposition of FA to produce hydrogen.

Porous organic copolymer (designated as CPOL-BP&P(OPh) 3 ) containing vinyl biphephos moieties and tris(4-vinylphenyl)phosphite (P(OPh) 3 ) moieties was synthesized through a solvothermal copolymerization technique. After metalation with Rh precursor, an efficient heterogeneous catalyst Rh/CPOL-BP&P(OPh) 3 for the hydroformylation of 1-butene is presented with high activity (TOF = 2490.3 h −1 ) and regioselectivity (l:b = 40.0). The Rh/CPOL-BP&P(OPh) 3 catalyst has been investigated by using solid-state 13 C MAS NMR, in situ FT-IR spectroscopy, nitrogen sorption measurements, SEM, TEM, and XPS. Interestingly, in situ FT-IR spectra showed that Rh species tended to coordinate with both two kinds of P species from biphephos and P(OPh) 3 ligands in the Rh/CPOL-BP&P(OPh) 3 polymer frame rather than one kind of them. Therefore, the synergistic effect of three kinds of coordination compound formed between Rh species and both ligands could be responsible for the high activity and regioselectivity observed in hydroformylation of 1-butene.

A series of hybrid coupling porous organic polymers (HC-3vPPh3-POLs) were designed and synthesized through copolymerizing any two of tris(4-vinphenyl) phosphine (p-3vPPh3), tris(3-vinphenyl) phosphine (m-3vPPh3) and tris(2-vinphenyl) phosphine (o-3vPPh3) in different proportions by solvothermal polymerization. The BET surface area of obtained HC-3vPPh3-POLs is varied from 534 to 1124 m2‧g−1 while the pore volume is changed from 0.43 to 2.25 cm3‧g−1, and the amount of micropores could also be regulated from 43.5 to 66.8%. The afforded Rh/HC-3vPPh3-POLs exhibit different conversions from 91% to 98%, selectivity to aldehyde from 79% to 90%, and the 1/b ratios from 4.0 to 11.1 (the ratio of the linear aldehydes to the branched aldehydes) by adjusting the PPh3 microenvironment and their quantities. The superior recyclability in an autoclave reactor and stability in a fixed-bed reactor of Rh/HC-3vPPh3-POLs demonstrate the excellent potential of this method in preparing functional materials for heterogeneous catalysis. Combined characterization methods were employed and demonstrated that P atoms from different vinyl functional PPh3 were uniformly dispersed and interacted with each other, leading to different structure and PPh3 microenvironment in HC-3vPPh3-POLs.

Porous organic copolymer (denoted as CPOL-BP&P) was afforded through the copolymerization of vinyl biphephos and tris(4-vinylphenyl)phosphine monomers under solvothermal conditions, and followed with impregnation method provided a highly efficient Rh/CPOL-BP&P catalyst with high activity (TOF = 11,200 h−1) and regioselectivity (the ratio of linear to branched aldehydes, l:b = 62.2) for heterogeneous hydroformylation of 1-butene. High regioselectivity was also obtained in the hydroformylation of butene mixture (2-butene: l:b = 55.8, isomeric mixture of butenes: l:b = 56.0). The Rh/CPOL-BP&P catalysts were thoroughly characterized by means of nitrogen sorption isotherms, in situ FT-IR, XPS, solid-state 31P MAS NMR, HAADF-STEM, SEM and TEM. The formation of unique coordination bonds with Rh species in the polymer skeleton was determined. Heterogeneous hydroformylation of butenes was effectively realized due to a synergetic effect between PPh3 moiety and biphephos moiety.

A series of Mg–porphyrin complex doped divinylbenzene (DVB) based porous organic polymers (POPs) were systematically afforded through the method of free radical polymerization under solvothermal conditions. These POP catalysts have physical advantages of high surface areas, hierarchical pore structures, high thermal stability and spatially separated active Mg–porphyrin sites, which lead to very high efficiency in the conversion of CO2 to cyclic carbonates with the aid of tetra-n-butyl ammonium bromide (TBAB) as a nucleophile. The effect of the doping ratio (Mg–porphyrin complex to DVB) on catalytic efficiency was studied and discussed, and the detrimental embedding effect was found. The effects of reaction temperature and pressure on catalytic activity as well as other epoxide substrates were also examined fully. More importantly, under very mild conditions (30 °C, 0.1 MPa CO2), a considerable turnover number (TON) value of 1800 was obtained. The heterogeneous POP catalyst can be easily recovered and reused 10 times without loss of activity.

Hydroformylation has been widely used in industry to manufacture high value-added aldehydes and alcohols, and is considered as the largest homogenously catalyzed process in industry. However, this process often suffers from complicated operation and the difficulty in catalyst recycling. It is highly desirable to develop a heterogeneous catalyst that enables the catalyst recovery without sacrificing the activity and selectivity. There are two strategies to afford such a catalyst for the hydrofromylation: immobilized catalysts on solid support and porous organic ligand (POL)-supported catalysts. In the latter, high concentration of phosphine ligands in the catalyst framework is favorable for the high dispersion of rhodium species and the formation of Rh-P multiple bonds, which endow the catalysts with high activity and stability respectively. Besides, the high linear regioselectivity could be achieved through the copolymerization of vinyl functionalized bidentate ligand (vinyl biphephos) and monodentate ligand (3vPPh3) into the catalyst framework. The newly-emerging POL-supported catalysts have great perspectives in the industrial hydroformylation.

Vinyl functionalized Xantphos ligand (denoted as 4v-Xantphos) was newly synthesized and successfully doped into the PPh3 based porous organic polymers (POPs) through the solvothermal synthesis technique. After proper coordination with Rh precursor, the resultant Xantphos doped Rh/POPs-PPh3 catalysts exhibited high activity (TOF: 300–500 h−1), chemoselectivity (87–91%) and regioselectivity (about 90:10) in the hydroformylation of long-chain olefins (C6-C12). As a representative substrate, hydroformylation of 1-octene could be easily realized in a fixed bed reactor for more than 400 h with high efficiency employing Xantphos doped Rh/POPs-PPh3 catalyst, which represented a rare successful example that realized heterogenization of homogeneous hydrofromylation catalysts as well as the regioselectivity-control at the same time without leaching of rhodium. Interestingly, the hydroformylation reaction data indicated that the Rh species tend to coordinate with the exposed P atom from Xantphos rather than that from PPh3 ligand in the Xantphos doped catalyst frame. More importantly, the HAADF-STEM and EXAFS characterizations indicated that Rh species demonstrated as single site dispersion in Xantphos doped Rh/POPs-PPh3 catalyst, thus endowed the catalyst with high activity. Detailed DFT calculations revealed that the unique location of single site dispersed Rh species (Rh species coordinated with both of Xantphos and PPh3 in the catalyst frame simultaneously) was responsible for the high linear regioselectivity and stability of the catalysts, the roles of Xantphos and PPh3 were further elucidated in details.

A new type of phosphorus-doped porous organic polymer (POP) has been readily synthesized through a Heck reaction, which could be used not only as a support but also a ligand for palladium nanoparticles. The dual-functional material supported palladium nanocatalyst was used for the efficient and chemoselective hydrogenation of varieties of nitroarenes and α,β-unsaturated compounds, as well as for the synthesis of indoles from 2-nitrophenylacetonitrile under 1 atm hydrogen in green solvents at room temperature. No obvious aggregation and loss of catalytic activity of the new nanocatalyst were observed after 10 runs in the reaction.

A single-component multifunctional catalyst (denoted as Mg-por/pho@POP) based on a magnesium porphyrin and phosphonium salt-integrated porous organic polymer (POP) was afforded via a solvothermal synthetic technique for cyclic carbonate production which uses epoxides and CO2. In consequence of the cooperative (or synergistic) effect of a phosphonium salt and homogeneously dispersed magnesium porphyrin moiety, which is possibly reinforced through the flexible frameworks and confined microporous structure, this powerful catalyst offered the highest activity of a heterogeneous catalyst within the context of cyclic carbonates synthesis from epoxide and CO2 (turnover frequencies up to 15,600 h–1) without the addition of co-catalysts. More surprisingly, very promising turnover numbers (TONs) of 14,400 and 4200 were realized at very mild temperatures of 25 and 40 °C. Moreover, Mg-por/pho@POP can be simply recovered and reused at least five times.

A new chiral monomer, (S)-5,5'-divinyl-BINAP, was successfully synthesized and embedded into two different porous organic polymers (Poly-1 and Poly-2). After loading a Rh species, the catalysts were applied for the heterogeneous asymmetric hydroformylation of styrene. Compared with the homogeneous BINAP analogue, the enantioselectivity of Rh/Poly-1 catalyst was drastically increased by approximately 70%. The improved enantioselectivity of the porous Rh/BINAP polymers was attributed to the presence of flexible chiral nanopockets resulting from the increased bulk of the R groups near the catalytic center. (C) 2017, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

An efficient protocol for heterogeneous hydroaminocarbonylation of olefins with ammonium chloride without addition of acid additive has been developed for the first time. We successfully synthesized the Pd@POPs-PPh3 catalyst through a solvothermal synthetic method. Under this heterogeneous catalytic system, C2-C6 olefins displayed good yields and TON, and a yield of 66% of propionamide and TON = 1400 were obtained under mild reaction conditions (403 K, Pethylene = 0.5 MPa, PCO = 2.5 MPa), which is a little higher than those in the homogeneous system. This catalytic system has the advantage of easy separation of product and catalyst, as well as good stability. Uniform dispersion of Pd active sites, strong coordination bond between P and Pd, high surface area, large pore volume and hierarchical porosity of Pd@POPs-PPh3 were confirmed by a series of characterizations, which is believed to be the keys for the good activity and stability of hydroaminocarbonylation reaction.

A series of cross-linked polymer supported ionic liquids based on quaternary ammonium salts have been prepared using a facile method of radical polymerization. Styrene-functionalized quaternary ammonium chloride salts, which are derived from imidazole, trimethylamine, triethylamine and triethanolamine, were copolymerized with divinyl benzene (DVB) under solvothermal conditions. These polymer supported ionic liquids displayed high efficiency in catalytic conversion of CO2 to cyclic carbonates. Notably, to the best of our knowledge, it was the first time that the polymeric ionic liquid catalyst was applied in a continuous flow fixed-bed reactor. During the study period of 130 hours, the polymer supported ionic liquids exhibited high stability.

A series of ionic liquid (IL), zinc halide (ZnX2), and triphenylphosphine (PPh3) integrated porous organic polymers (POPs) featuring multifunctional sites were afforded through solvothermal synthesis for cyclic carbonate synthesis which utilizes epoxides and carbon dioxide (CO2). Owing to the cooperative effect of ionic liquid and homogeneously distributed Zn-PPh3 specie, which is probably strengthened by the confined microporous structure and flexible frameworks, these POPs catalysts exhibited high CO2 capture and conversion performance and provided the highest activity (initial turnover frequencies up to 5200 h–1) of heterogeneous catalysts reported to date within the context of cyclic carbonate formation. Even more surprising, very favorable turnover numbers (TONs) of 2120 and 720 were attained at 40 and 25 °C, respectively. The effect of reaction parameters (reaction time, temperature, CO2 pressure) on the catalytic performance as well as other epoxide substrates were also investigated in detail. Furt...

CuS nanoflowers, fabricated by an element-direct-reaction route using copper and sulfur powder, were loaded on rutile TiO 2 (CuS/TiO 2 ) at low temperature. CuS/TiO 2 composites were utilized as the photocatalysts for the degradation of Methylene Blue (MB) and 4-chlorophenol (4-CP). X-ray diffraction (XRD), UV Raman spectroscopy, transmission electron microscopy (TEM), XPS, and UV-visible diffuse reflectance spectra were used to characterize the crystalline phase, morphology, particle size, and the optical properties of CuS/TiO 2 samples. It is found that CuS/TiO 2 photocatalyst, which CuS are loaded on the surface of rutile TiO 2 , exhibited enhanced photocatalytic degradation of MB (or 4-CP) than TiO 2 or CuS. This indicates that CuS can enhance effectively the photocatalytic activity of rutile TiO 2 by forming heterojunction between CuS and rutile TiO 2 , which is confirmed by photoluminescence (PL) spectra and TEM. Moreover, CuS content has a significant influence on photocatalytic activity and 2 wt% CuS/TiO 2 showed the maximum photocatalytic activity for degradation of MB.

Heterogeneous, metal, single-site catalysts often exhibit higher catalytic performance than other catalysts because of their maximized atom efficiency of 100 %. Reported herein is a precoordination/solvothermal polymerization strategy to fabricate a stable mononuclear Pd-metalized porous organic polymer catalyst (Pd@POP). Pd@POP was easy to use in regioselective organic reactions because the internal structure of this Pd@POP can be easily modified. The catalyst was used to solve the intractable regioselectivity problems of Heck reactions. Pd@POP-9 can efficiently activate the ends of olefins, thereby leading to high selectivity for substitution at the external position. To understand the reason underlying the high selectivity and activity of the catalyst, the systemic characterization of Pd@POP-9 and density-functional theory calculations were conducted. This Heck reaction is the first to be catalyzed by a recyclable mononuclear metal catalyst with unprecedented catalytic activity and regioselectivity.

A series of Mg-porphyrin complex doped divinylbenzene (DVB) based porous organic polymers (POPs) were systematically afforded through the method of free radical polymerization under solvothermal conditions. These POP catalysts have physical advantages of high surface areas, hierarchical pore structures, high thermal stability and spatially separated active Mg-porphyrin sites, which lead to very high efficiency in the conversion of CO

Rh/SiO2 catalysts with tethered-phosphines with different alkyl spacer lengths have been prepared, tested and characterized. Lengthening the alkyl spacer of the tethered-phosphine improved the flexibility of tethered-phospine, promoted the formation of active species and enhanced the activity of hydroformylation over other tethered-phosphine modified Rh/SiO2 catalysts.

A facile method for the preparation of heterogeneous asymmetric hydrogenation catalysts was presented. BINAP was knitted with aryl compounds using formaldehyde dimethyl acetal (FDA) as a cross-linker by Friedel–Crafts reaction without any pre-modification. The prepared catalysts showed different catalytic activities, and excellent recyclablilty results could be achieved in asymmetric hydrogenation.

A series of quaternary phosphonium salt and ZnX2–PPh3 integrated hierarchical porous organic polymers (POPs) with tailorable stoichiometric copolymerization proportions were obtained through the method of solvothermal synthesis. The resultant POP materials feature hierarchical porous structures, high BET surface areas (up to 1115 m2 g−1), excellent CO2 uptake abilities (87 mg g−1 at 273 K under 1 atm CO2) and multifunctional sites. Owing to the cooperative effect of quaternary phosphonium salt and homogeneously distributed ZnX2–PPh3 species, which is probably strengthened by the confined hierarchical structure and flexible frameworks, these POP catalysts provided the highest activity (initial turnover frequencies up to 6022 h−1) among heterogeneous catalysts reported to date within the context of cyclic carbonate formation. The effect of reaction parameters (reaction time, temperature, and CO2 pressure) on the catalytic performance as well as other epoxide substrates was also investigated in detail. Furthermore, these catalysts can be easily recovered and reused five times without a significant loss of activity.

A vinyl functionalized biphephos ligand with high steric hindrance was copolymerized with tris(4-vinphenyl)phosphane and other ligands to afford efficient porous organic copolymers (POPs) through the solvothermal synthesis technique. By employing the copolymer self-supported heterogeneous Rh/CPOL-bp&P catalysts, the hydroformylation of propene to linear-butaldehyde can be performed efficiently in a continuous fixed-bed reactor with high regioselectivity (l/b > 24), activity (TOF > 1200 h−1) and stability (over 1000 h) under mild conditions (70 °C, 0.5 MPa), which represents a substantial improvement in the efficiency of this important industrial process. EXAFS and HAADF-STEM showed that the Rh was a single atom dispersion, which explained well the high efficiency of the Rh/CPOL-bp&P catalysts. Compared with liquid–liquid biphasic (LLB) and ionic liquid (IL) systems, this highly efficient solvent free system has the advantages of simple operability, and almost no waste emission, which meets the demands of green industrial processing.

Vinyl functionalized Biphephos ligand, denoted as vinyl biphephos, has been succesfully synthesized. Copolymerization of vinyl biphephos with tris(4-vinphenyl) phosphane can afford an efficient Porous Organic Polymer (POP), CPOL-bp&PPh3. The ultimately formed Rh/CPOL-bp&PPh3 heterogeneous catalyst showed excellent performance in converting terminal olefins to the corresponding linear aldehydes with high regioselectivity (l/b = 96 : 4–98 : 2), activity and stability, even better than the comparable homogeneous Rh + vinyl biphephos system. Notably, isomerizing hydrofromylation of internal olefins (2-heptene, 2-octene, trans-3-hexene) was also performed with high regioselectivity (l/b = 92 : 8–93 : 7) using the Rh/CPOL-bp&PPh3 heterogeneous catalyst.

a three-fold cross-linked polymer-bound phosphine (pol-ph3p) with high phosphorus content has been prepared. the phosphorus-containing polymer forms a monodentate-p-ligated palladium complex, which shows excellent activity in suzuki-miyaura cross-coupling reactions of aryl chlorides. importantly, the catalyst pd/pol-ph3p is highly stable and can be reused for at least 10 times without losing reactivity.

The interlayer inserted between the active layer and ITO has been demonstrated to be crucial for the performance of inverted polymer solar cells (i-PSCs). In this work, we find that ionic liquids (ILs) can significantly enhance the efficiency of i-PSCs. With the ZnO/IL interfacial layer, PTB7-Th : PC71BM i-PSCs can exhibit a champion power conversion efficiency (PCE) of 10.15%, which is among the highest PCEs reported thus far for single-junction bulk heterojunction solar cells through the solution process. The IL layer and ZnO/IL combination layer with low work function, good optical transmittance, improved electron extraction and reduced resistance at the cathode interface have been demonstrated to be excellent and general interfacial layers for i-PSCs.

Thiophenes containing an adjacent C≡C group as ligands for PdII-promoted organic reactions are reported for the first time. These ligands were utilized as catalytic sites and integrated into the skeleton of conjugated microporous polymers. By employing these CMP materials as selective regulators, oxidative Heck reactions between arylboronic esters and electronically unbiased alkenes provide highly selective linear products.

The study aimed to investigate the relationship between heart-carotid pulse transit time and carotid intima-media thickness (CIMT) in hypertensive patients, and whether including the pre-ejection period (PEP) in heart-carotid pulse transit time would affect this correlation. A total of 62 hypertensive patients were included in this study. They were divided into the normal CIMT group (n=33, CIMT⩽0.8 mm) and the thickened CIMT group (n=29, CIMT>0.8 mm). The noninvasive ultrasound method was used to measure CIMT, electrocardiogram R-wave-based heart-carotid pulse transit time (rcPTT) and PEP. Aortic valve-carotid artery pulse transit time (acPTT) was calculated by subtracting PEP from rcPTT. Simple linear analysis showed that CIMT was negatively associated with rcPTT and acPTT (r=-0.57, P

Design and performance of a coplanar waveguide (CPW) bandpass filter (BPF) using composite right/left-handed (CRLH) zeroth-order resonators have been studied. The unit cell of the CRLH CPW consists of a series interdigital capacitor and two shunt stub inductors embedded between two sections of CPWs. The Bloch analysis is applied based on the S parameters to derive the characteristics of the eigen modes (Bloch modes), from which the right/left-handed frequency band and the zeroth-order resonant frequency are clearly determined. Then, the susceptance slope parameter of the resonator is extracted and the admittance (J-) inverters are introduced to synthesize a capacitively coupled CPW BPF. The measured performance agrees with the simulated one. They show that the size of the filter is greatly reduced (more than 60%) when compared to a conventional structure.

Correction for ‘Highly recyclable polymer supported ionic liquids as efficient heterogeneous catalysts for batch and flow conversion of CO2 to cyclic carbonates’ by Tao Wang et al., RSC Adv., 2017, 7, 2836–2841.

Large-scale synthesis of high-quality GaN nano-crystallites has been achieved by direct reaction of a 4:1 molar Ga/Ga2O3 mixture with ammonia at 950degreesC. X-ray diffraction, transmission electron microscopy, selected-area electron diffraction and high-resolution transmission electron microscopy revealed that the produced GaN nanocrystallites were single hexagonal wurtzite structure with an average particle size around 45 nm. A sharp near band edge emission peak and a blue light emission peak were observed in photoluminescence spectroscopy. The synthesis approach is simple and easy to be commercialized.

An accurate equivalent circuit model and the parameter extraction method are presented for the microstrip line with a complementary split ring resonator. A highpass filter with steep rejection slope is designed based on the model. Numerical simulation and measurement confirms the efficient analysis and design procedure and the validity of the highpass filter configuration.