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The Rh/BINAPa and ZSM-35(10) co-catalyzed tandem hydroformylation–acetalization of olefins is developed to afford the corresponding acetals with high regioselectivities and excellent catalytic activities.

An efficient homogeneous Rh/PPh3 catalyst and a reusable heterogeneous Rh/POP-PPh3-SO3Na catalyst have been developed for the isomerization of 1-alkenes to (E)-2-alkenes, respectively.

A type of fluorescent lignin ionic complexes is developed via the electrostatic complexation between ligninsulfonate and a tetraphenylethene-containing ammonium surfactant. These materials could be recyclable labeling biomaterials suitable for working at high temperatures and hydrophobic coating materials.

By forming a locked cis-state, the designed azobenzene-containing surfactant maintains the isotropic liquid state of DNA materials after ceasing UV light, which shows resistance to thermal and mechanical stimuli but sensitivity to Vis light.

A reusable Pd/Cu bimetal-loaded porous organic polymer (Pd/Cu@POP–POPh3) has been developed for heterogeneous oxidation of various alkynes to afford the corresponding 1,2-diketones in high to excellent yields.

Cyclohexanone is widely used in coatings, pesticides, dyes, lubricants, and other industries due to its high solubility and low volatility, but designing highly active and stable heterogeneous cata...

The preparation of small molecule compounds with a high value from biomass has always been the focus of research, and catalysts with high activity and stability are an essential part of biomass con...

A series of carboxylic acid-functionalized deep eutectic solvents(DES) wereconstructed by a natural organic dicarboxylic acid, oxalic acid (OA), as the hydrogen bond donor and the polyethylene glycol (PEG)with different polymerization degrees as the hydrogen bond acceptors, which are used in the hydration of α-pineneto produce α-terpineol. Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1H NMR), and thermogravimetric analysis (TGA) were used to prove the hydrogen bonding between OA and PEG. It is found that the presence of PEG has a less impact on the acid strength of DES. However, an increase in both molecular weight and dosage of PEG results in a decrease in total acidity and catalytic activity.Among them, OA/0.6PEG200, a DES catalyst prepared by PEG with the smallest molecular weight, exhibits a favorable catalytic performance. Under an optimal reaction condition with 0.03 mol of DES (based on OA), 0.06 molof α-pinene, 0.3 mol of water,at 75°C for 8 h, anα-pinene conversion of 81.5% and an α-terpineol selectivity of 51.2% are obtained. The catalyst phase can be separated by refrigerating overnight after reaction and reused directly with relatively stable catalytic performance. Thus, OA/0.6PEG200, as a DES catalyst prepared by a simple and highly atom economical process, will offer a clean catalytic route for the one-step production of α-terpineol.

Background (R)-(+)-perillyl alcohol is a naturally oxygenated monoterpene widely used as the natural flavor additives, insecticides, jet fuels and anti-cancer therapies. It was also readily available monoterpene precursors. However, this natural product is present at low concentrations from plant sources which are not economically viable. Therefore, alternative microbial production methods are rapidly emerging as an attractive alternative to make (R)-(+)-perillyl alcohol production more sustainable and environmentally friendly. Results We engineered Escherichia coli to possess a heterologous mevalonate (MVA) pathway, including limonene synthase, P-cymene monoxygenase hydroxylase and P-cymene monoxygenase reductase for the production of (R)-(+)-perillyl alcohol. The concentration of (R)-(+)-limonene (the monoterpene precursor to (R)-(+)-perillyl alcohol) reached 45 mg/L from glucose. Enhanced (R)-(+)-perillyl alcohol production was therefore achieved. The strain produced (R)-(+)-perillyl alcohol at a titer of 87 mg/L and a yield of 1.5 mg/g glucose in a 5 L bioreactor fed batch system. Conclusions These datas highlight the efficient production of (R)-(+)-perillyl alcohol through the mevalonate pathway from glucose. This method serves as a platform for the future production of other monoterpenes.

A sulfoxantphos modified palladium-catalyzed synthesis of α,β-unsaturated carboxylic acids from alkynes with CO and H2O was described. The atom-economic hydroxycarbonylation of various symmetrical and unsymmetrical alkynes can be achieved with chemo-, stereo-, and regioselectivity, affording the corresponding carboxylic acids in good to excellent yields. Using water as the reaction solvent, the water-soluble palladium catalyst was easily separated from the product and could be reused for 5 cycles.

Solid-state spiropyrans would be excellent materials for solar energy storage, information storage, etc., if they could furnish the light-induced isomerization process at room temperature. However, solid-state spiropyrans with fully reversible photochromic properties at room temperature are extremely rare, due to the lack of sufficient free room for a photoisomerization process. The currently reported solid-state photochromic spiropyrans highly rely on the introduction of bulky rigid groups for creating the needed free room. In this work, via increasing the molecular flexibility, a new strategy for designing solid-state spiropyrans showing highly efficient reversible photochromism at room temperature has been developed. By attaching a flanking alkyl chain to the indole nitrogen, the as-prepared T-type spiropyrans exhibit fast photoresponsive properties. More attractively, this kind of spiropyran could be conveniently “evolved” into a new solid state showing advanced photochromic and thermochromic properties with three different colors. With good room temperature stability and excellent one-to-one correspondences between stimuli and colors, these solid-state spiropyrans are proved to be advanced information storage materials in our logic gate test. This work will provide a new strategy for designing advanced materials with solid-state photochromic molecules in low-molecular-weight.

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2D heterostructures provide a competitive platform to tailor electrical property through control of layer structure and constituents. However, despite the diverse integration of 2D materials and their application flexibility, tailoring synergistic interlayer interactions between 2D materials that form electronically coupled heterostructures remains a grand challenge. Here, the rational design and optimized synthesis of electronically coupled N-doped mesoporous defective carbon and nitrogen modified titanium carbide (Ti

The functions of the materials composed of small molecules are highly dependent on their ordered molecular arrangements in both natural and artificial systems. Without ordered structure, small molecules hardly gain complicated functions, due to the absence of intermolecular covalent bond connection or strong network. Here, a low molecular weight spiropyran that could exhibit attractive photochromism and powerful adhesion property in disordered solid state is demonstrated. With maximum up to ∼8 MPa, the adhesion strength could be photoregulated in multiple levels, which also shows one-to-one correspondence to the specific color state. The working mechanism analysis on the photoregulated adhesion reveals that the isomer ratio of merocyanine form and the molecular packing density of spiropyran are the determining factors for the adhesion ability. The discovery of photoregulated adhesion from pure spiropyran provides a new strategy for developing functional materials by employing low molecular weight compounds.

Hydration of α-pinene catalyzed by a natural deep eutectic solvent (NADES) prepared by oxalic acid dihydrate (OA·2H2O) and betaine (Bet), 2.7OA·2H2O/Bet, has been studied to develop a more economical and green process for one-step hydration method. It has been found that a homogeneous ternary DES system could be established with OA·2H2O and Bet in a simple, convenient, and atomic economy way. Fourier transform infrared spectrum (FT-IR), proton nuclear magnetic resonance (1H NMR), thermogravimetry (TG), and differential scanning calorimetry (DSC) have been applied to confirm the formation of hydrogen bonding between OA, H2O, and Bet. With the consideration of catalytic activity, selectivity, and ability to recycle, 2.7OA·2H2O/Bet has been screened out to be a promising catalyst for hydration of α-pinene due to its appropriate acidic properties and solubility. In this catalytic system of hydration, water, as one of the reactants, both assisted in the formation of DES and acted as the dispersing agent. Correspondingly, an “emulsifying reaction at the reaction temperature and solid-liquid separation below room temperature” characteristic of this specific catalytic hydration of α-pinene has been achieved.

The new catalyst Pd@mSiO2 was synthesized by a simple and gentle one-step process, mesoporous silica as the shell and metal particles as the core. The characterization showed that the catalyst structure was regular, the core–shell structure was clear, and each microsphere guarantees the existence of a single nucleus. The pore size and the thickness of mesoporous silica layer can be effectively adjusted by adjusting the molecular weight of template and the amount of silicon source. The Pd@mSiO2 was applied in the hydrogenation of levulinic acid to prepare γ-valerolactone, the conversion of levulinic acid was 95%, and the selectivity of γ-valerolactone was close to 96%. In addition, the catalyst had a good reuse performance compared to commercial catalysts. After repeated use for ten times, the catalytic activity did not decrease, which was mainly attributed to the fact that the core–shell structure can better protect the active metal particles and prevent the particles from agglomeration and loss at high temperature.

A one-pot clean preparation procedure and catalytic performance of platinum nanoparticles (NPs) reduced and stabilized by sodium lignosulfonate in aqueous solution are reported. No other chemical reagents are needed during the metal reduction and stabilization step, thanks to the active participation of sodium lignosulfonate (SLS). UV-vis, Fourier transform infrared (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), 1H NMR, 195Pt NMR, and two-dimensional heteronuclear single-quantum coherence (2D HSQC) NMR studies were thoroughly performed to analyze the formation, particle size, and main lattice planes of NPs, the valence-state changes of the metal, and structural changes of SLS. An ecofriendly selective synthesis of cis-pinane from an abundant renewable natural resource, α-pinene, was developed in the presence of the prepared Pt NP aqueous system. Furthermore, this catalyst system was proved to show easy recovery and stable reusability by five-run tests. The synergistic effect of SLS reduction and stabilization not only avoided the introduction of conventional reducing agents and stabilizers but also made full use of the byproducts of the pulp and paper industry. This proved to be an environmentally friendly method for converting the natural resource α-pinene to cis-pinane.

A completely water soluble azobenzene chemosensor 1 for selective detection of Hg2+ was synthesized. Taking advantage of the absorption changes corresponding to the transition moments polarized along the short axis of an azobenzene, 1 showed characteristic UV-Vis signal changes in the band around 240 nm for Hg2+ in wide pH ranges, which also showed good tolerance to various metal ions and photoirradiation. Upon addition of Hg2+ into the solution of 1, a favored formation of trans-1 was observed, which is attributed to an intramolecular coordination of the PEG chain and Nβ to Hg2+ confirmed by a control experiment test.

In this study, a novel silk fibroin films with robust mechanical properties was fabricated by dissolving silk under ultraviolet light (Uv-light) in ionic liquid. Uv-light irradiation can promote the transformation of the silk fibroin structure from the α-helix to the β-sheet, thereby the strength of the film was enhanced. The wavelength of the Uv-light, the irradiation time and the distance from the light source all have an effect on the strength of the silk fibroin film. Under the optimum conditions, the strength of silk fibroin film could reach 23.7Mpa, which was nearly 85% higher than that of the conventional system. In the meantime, the wettability and swellability of the film were investigated. The results showed that groups with oxygen atoms on the surface of silk fibroin film increased after irradiation, and its wettability and swellability increased significantly, which was more conducive to cell adhesion. Furthermore, the silk fibroin film exhibit excellent biocompatibility, supporting L-929 (mouse fibroblasts) adhesion and proliferation. The study provides a new direction for the preparation of high-strength silk fibroin films, as well as its application in life sciences.

Lactate and isoprene are two common monomers for the industrial production of polyesters and synthetic rubbers. The present study tested the co-production of D-lactate and isoprene by engineered Escherichia coli in microaerobic conditions. The deletion of alcohol dehydrogenase (adhE) and acetate kinase (ackA) genes, along with the supplementation with betaine, improved the co-production of lactate and isoprene from the substrates of glucose and mevalonate. In fed-batch studies, microaerobic fermentation significantly improved the isoprene concentration in fermentation outlet gas (average 0.021 g/L), compared with fermentation under aerobic conditions (average 0.0009 g/L). The final production of D-lactate and isoprene can reach 44.0 g/L and 3.2 g/L, respectively, through fed-batch microaerobic fermentation. Our study demonstrated a dual-phase production strategy in the co-production of isoprene (gas phase) and lactate (liquid phase). The increased concentration of gas-phase isoprene could benefit the downstream process and decrease the production cost to collect and purify the bio-isoprene from the fermentation outlet gas. The proposed microaerobic process can potentially be applied in the production of other volatile bioproducts to benefit the downstream purification process.

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Energetic compounds containing long nitrogen chain, have been a research hotspot. Fused heterocycles are stable due to their aromatic systems. The compound obtained by combining long nitrogen chain and fused ring can not only retain good energetic property, but also ensure better stability. This work designed eight fused heterocycle-based energetic compounds, 3H-tetrazolo[1,5-d]tetrazole (1) and its derivatives (2-8), containing a nitrogen chain with seven nitrogen atoms. The HOF, thermal stability, and energetic properties of these compounds were studied by using the DFT method. The results show that the introduction of -NO2, -N3, -NF2, -ONO2, -NHNO2 groups increased the density, HOF, detonation velocity, and detonation pressure greatly. The densities of 3, 5, 7, and 8 fall within the range designated for high-energy-density materials. The calculated detonation velocity of the compounds 3 and 8 are up to 9.86 km s-1 and 9.78 km s-1, which are superior to that of CL-20. The kinetic study of the thermal decomposition mechanism indicates that the N-R bonds maybe not the weakest bonds of these compounds. The tetrazole ring opening of the heterocycle-based energetic compounds, followed by N2 elimination is predicted to be the primary decomposition channel, whether or not they have substituent groups.

A series of amino-acid-based ionic liquids was synthesized via one-step protonation of the corresponding L-amino acid by utilizing an array of proton sources. The catalytic activity of the amino-acid-based ionic liquids for the Baeyer-Villiger oxidation of cyclic ketones was investigated using cyclopentanone as a model cycloketone. The proline-based ionic liquid [ProH]CF3SO3 was shown to exhibit the best catalytic activity. The reaction condition was optimized to give the following reagent ratio of n(cyclopentanone):n(catalyst):n(H2O2)=1:0.06:4, 60 °C and 6 h. Under the optimum conditions, the conversion of cyclopentanone was 96.57% and the selectivity for δ-valerolactone was 73.01%. The catalytic activity was shown to be constant after 4 cycles. A simple treatment was allowed for the recover and the reuse of [ProH]CF3SO3. The successful utilization of [ProH]CF3SO3 to catalyze a host of cyclic ketones via Baeyer-Villiger oxidation clearly demonstrated the capacity of [ProH]CF3SO3 to tolerate variation in the substrate.

Ruthenium (Ru) nanoparticles synthesized using hydroxyethyl cellulose (HEC-Ru) were used to hydrogenate α-pinene in an aqueous medium. The results showed that HEC had a good dispersion effect on Ru nanoparticles and most of the particle sizes were ranged from 4 to 6 nm. The micelles formed with HEC appeared to act as “microreactors” in which the Ru nanoparticles had good stability and uniform distribution. In addition, α-pinene was loaded into the HEC micelles through hydrophobic interaction, resulting in good contact with Ru nanoparticles. Thereby, HEC-Ru nanoparticles significantly improved the hydrogenation of α-pinene, and 99.6% of α-pinene conversion and 98.6% of cis-pinane selectivity were obtained. Compared with the Pd/C, Ru/H2O, and HEC-Ru/ethanol catalyst systems, the HEC-Ru/H2O system had the maximum α-pinene conversion. In addition, considerable α-pinene conversion could be obtained after 10 times reuse with no fresh addition.

In aqueous medium without any other additives, palladium (Pd) nanoparticles with water-soluble polyvinyl alcohol (PVA) as stabilizer were synthesized for the catalytic hydrogenation of nitrobenzene. Under the optimum experimental conditions, the nitrobenzene conversion and the selectivity for aniline were 99.3 % and 100 %, respectively. Comprehensive characterization methods, including TEM, UV/Vis, confocal laser scanning microscopy (CLSM), XRD and XPS allowed a better understanding of the role of PVA aggregates and the properties of Pd nanoparticles. The nitrobenzene conversion exceeded 80 % even after 6 cycles without any treatment of the catalyst. A mechanism about the hydrogenation of nitrobenzene catalyzed by Pd/PVA system was proposed. The Pd/PVA catalyst also exhibited excellent activity and selectivity, particularly to ortho-fluoronitrobenzene and ortho-nitrotoluene. This research can provide a reference for the environmentally friendly catalysis for hydrogenation of nitrobenzene and other substituted nitrobenzene compounds.

Two types of carbon microspheres with abundant nitrogen-containing groups and porous structure were prepared via feasible and cost-effective methods, using chitosan (NCS-T) and glucose (NCSNH3-T) as the raw materials, chitosan and ammonia as nitrogen source respectively. The effect of nitrogen sources on structure of N-doped porous carbon and their supercapacitors/CO2 adsorption performance were discussed in details. The obtained carbon materials both exhibit a graphite-like structure with developed porous structures. For the NCS-T samples, N-5 and N-6 were the main nitrogen-containing groups, and O Ⅰ and O Ⅱ were the main oxygen-containing groups. For NCSNH3-T samples, N exists as N-5, N-6 N-Q, and N-X groups, and O exists as O Ⅰ, O Ⅱ, and O Ⅲ groups. Micro-mesoporous structures developed, and on the specific surface area, pore volumes are more developed in NCSNH3-T, mainly due to ammonia activation, which results in additional micropores especially ultramicropores (sizes＜0.9 nm). The obtained carbon materials are well suited for use as an electrode material and adsorbent. In three-electrode system, the specific capacitances were in the range of 96–161 F/g for NCS-T, and the values reached 220–244 F/g for NCSNH3-T at 0.2 A/g in 1 M H2SO4 electrolyte, it's the combination of electric double layer capacitors and faradaic pseudocapacitance. The CO2 capture capacities were 51–141 mg/g for NCS-T and 180–243 mg/g for NCSNH3-T, due to the developed micropores and ultramicropores. The results suggest that NCSNH3-T can be a candidate as both electrode material and adsorbent.

In this work, Mo-MCM-41, Zr-MCM-41, Sn-MCM-41 and Ti-MCM-41 mesoporous molecular sieves were successfully synthesized via hydrothermal synthesis. An acidic group (SO42−, PTSA etc.) was introduced into the mesoporous molecular sieves to obtain modified mesoporous molecular sieve catalysts. The XRD, N2 absorption–desorption isotherms, FT-IR and Py-IR results reveal that PTSA/ZrO2/Mo-MCM-41 had a mesoporous molecular sieve structure containing a large number of acidic centers. The PTSA/ZrO2/Mo-MCM-41 catalyst illustrated superior catalytic performance for synthesis of rosin methyl ester and the esterification rate was 88.2% under the optimized conditions. At the same time, the PTSA/ZrO2/Mo-MCM-41 catalyst has excellent stability and can be recycled and reused with negligible loss in activity over six cycles.

Enhanced 5-hydroxymethylfurfural (5-HMF) production from cellulose was achieved using a novel and clean Ni-doped biomass-based carbon catalyst (Nin/CS) under hydrothermal degradation conditions. The obtained catalyst was characterized by ICP-AES, N2 adsorption–desorption, TEM, XPS, XRD, FT-IR, NH3-TPD, and pyridine IR. Abundant hydroxyl and carboxyl groups were present on the biomass-based carbon spheres (CSs), providing Lewis and Bronsted acid active sites. Furthermore, adding a Ni source increased the total acid content and the Bronsted acid strength. Ni mainly existed in its metallic form and was embedded in the porous carbon skeleton, providing active sites for cellulose adsorption and catalytic conversion. The effect of Ni dose, reaction time, and reaction conditions on 5-HMF production were investigated and optimized, acid catalyzed hydrolysis instead of hydrogenation reaction occurred when the parameters were optimized. A 5-HMF yield of 85% was obtained when cellulose (1 g) was reacted with H2 (6 MPa) at 200 °C for 60 min using Ni2.0/CS (200 mg) as catalyst.

Highly dispersed and stable catalysts comprising Ru nanoparticles supported on boron-doped amphiphilic core-shell mesoporous molecular sieves (MMS-C@MMS-NH2/B/Ru) with alkyl-modified hydrophobic silica core and NH2-functionalized hydrophilic silica shell are successfully prepared for use in hydrogenation of alpha-pinene for the first time. Dodecyl-modified MMS-C-12@MMS-NH2/B/Ru exhibits the best catalytic activity under mild hydrogenation conditions. The abundant -NH2 functional groups on the molecular sieve surface and their amphipathy allow the sieves to facilitate attachment of more Ru nanoparticles, and to simplify their dispersion in the water-organic reaction medium. Moreover, B-doped molecular sieves may adjust their acidity to meet the needs of alpha-pinene hydrogenation. Under mild reaction conditions (25 degrees C, 1 MPa H-2, and 1 h), alpha-pinene can be completely converted with 99 % selectivity to cis-pinane, because every nanocomposite is equivalent to a microreactor. The catalytic activity does not change much over 5 cycles, indicating that Ru nanoparticles are stably loaded on the molecular sieves.