CO2 Methanation via Amino Alcohol Relay Molecules Employing a Ruthenium Nanoparticle/Metal Organic Framework Catalyst

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

Development of unique dianionic Ir(III) CCC pincer complexes with a favourable spirocyclic NHC framework

Science China Chemistry - A new type of dianionic Ir(III) CCC pincer complexes (SNHC-Ir, 1a-1c) is successfully designed and synthesized by developing a one-step methodology, which involves an...     

The Sensitized Solid‐Phase Electrochemiluminescence of Electrodeposited Poly‐Luminol/Aniline on AuAg/TiO2 Nanohybrid Functionalized Electrode for Flow Injection Analysis

In this study, a copolymer of luminol with aniline is electrochemically deposited onto the AuAg/TiO₂ nanohybrid functionalized indium tin oxide coated glass. It is used as a reagentless electrochemiluminescent (ECL) electrode for flow‐injection‐analysis (FIA). The properties of this solid phase ECL electrode are characterized by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy etc. It has stronger ECL emission, sensitive response for target analytes and excellent stability. The so‐prepared ECL electrode shows sensitive response to reactive oxygen species thereafter to be applied for determination of hydrogen peroxide with FIA mode. Under optimized conditions, a mass detection limit of 0.822 pg of hydrogen peroxide was obtained. Thus the hydrogen peroxide residues in samples were detected with satisfactory result.     

Catalytic Asymmetric Formal [3+3] Cycloaddition of an Azomethine Ylide with 3‐Indolylmethanol: Enantioselective Construction of a Six‐Membered Piperidine Framework

A catalytic asymmetric formal [3+3] cycloaddition of 3‐indolylmethanol and an in situ‐generated azomethine ylide has been established to construct a chiral six‐membered piperidine framework with two stereogenic centers. This approach not only represents the first enantioselective cycloaddition of isatin‐derived 3‐indolylmethanol, but also has realized an unusual enantioselective formal [3+3] cycloaddition of azomethine ylide rather than its common [3+2] cycloadditions. Besides, this protocol combines the merits of a multicomponent reaction and organocatalysis, which efficiently assembles a variety of isatin‐derived 3‐indolylmethanols, aldehydes, and amino esters into structurally diverse spiro[indoline‐3,4′‐pyridoindoles] with one all‐carbon quaternary stereogenic center in high yields and excellent enantioselectivities (up to 93 % yield, >99 % enantiomeric excess (ee)). Although the diastereoselectivity of the reaction is generally moderate, most of the diastereomers can be separated by using column chromatography followed by preparative TLC.     

三层同轴电喷-去模板法制备核壳纳米颗粒用于蛋白质药物输送

分别以聚乙二醇(PEG)、聚(丙交酯-乙交酯)(PLGA)和牛血清白蛋白(BSA)为冠、壳和核层材料,采用三层同轴电喷技术制备得到微米颗粒.激光共聚焦显微镜(LSCM)显示,该方法制备得到的微米颗粒呈现核-壳-冠结构.通过脱去该微米颗粒的PEG冠层(模板),得到包载有BSA的纳米颗粒.研究发现,随着壳层PLGA溶液进样速度的减慢,去模板后纳米颗粒的粒径从约146 nm减小到68 nm.BSA在纳米颗粒中的包埋率可高达78.3%,并且其释放没有显著的药物暴释现象.圆二色谱结果表明,同轴电喷过程对BSA二级结构影响很小.因此,利用三层同轴电喷-去模板法可制备得到粒径可调控的蛋白质纳米载体系统,并且该过程中蛋白质的结构基本维持不变.     

Graphene-wrapped Ni2P materials: a 3D porous architecture with improved electrochemical performance

Ni₂P/graphene hybrid with a 3D architecture has been successfully accomplished through a series of controlled chemical processes. In contrast to random mixture of Ni₂P nanoparticles and graphene nanosheets, the architecture hybrid exhibits superior electrochemical stability because the Ni₂P nanoparticles are firmly riveted on the graphene sheets. The 3D graphene network enhances the electrical conductivity over the 2D nanostructure. As anode materials for lithium-ion batteries, the graphene-wrapped Ni₂P nanoparticles can deliver a reversible capacity of ~400 mAh g^?1 after 30 cycles with nearly no fading and also exhibit a good rate performance. The graphene network can serve as a conducting network for fast electron transfer from all directions between the active materials and charge collector, and better buffer spaces to accommodate the volume expansion/contraction during discharge/charge process, which can be considered to contribute to the remarkable cyclic stability, thereby pointing to a new synthetic route to hybridizing graphene with active materials for advanced lithium ion batteries.

Facile One-Pot,Multicomponent Synthesis of Pyridines Under Microwave Irradiation

A series of 2-amino-6-(2-oxo-2H-chromen-3-yl)-4-pyridine-3-carbo-nitriles were synthesized by the one-pot, multicomponent reaction of 3-acetyl-coumarin, aromatic aldehydes, malononitrile, and ammonium acetate in acetic acid under microwave irradiation. The reactions were completed in 10–13 min with 61–86% yields, were environmental benign, and had easy workup. Their structures were confirmed by ¹H NMR, IR, and MS spectra and elemental analysis.     

A Facile and Expeditious Microwave‐Assisted Synthesis of Furo[3,4‐b]indeno[2,1‐f]quinolin‐1‐one Derivatives via Multicomponent Reaction

A series of furo[3,4‐b]indeno[2,1‐f]quinolin‐1‐one derivatives were synthesized by the condensation of an aromatic aldehyde with tetronic acid and 9H‐fluoren‐2‐amine in solvent of glacial acetic acid under microwave irradiation. This procedure offers several advantages including operational simplicity, clean reaction, and increased safety for small‐scale high‐speed synthesis.     

Direct determination of chlorophenols in water samples through ultrasound-assisted hollow fiber liquid–liquid–liquid microextraction on-line coupled with high-performance liquid chromatography

In this study we on-line coupled hollow fiber liquid–liquid–liquid microextraction (HF-LLLME), assisted by an ultrasonic probe, with high-performance liquid chromatography (HPLC). In this approach, the target analytes – 2-chlorophenol (2-CP), 3-chlorophenol (3-CP), 2,6-dichlorophenol (2,6-DCP), and 3,4-dichlorophenol (3,4-DCP) – were extracted into a hollow fiber (HF) supported liquid membrane (SLM) and then back-extracted into the acceptor solution in the lumen of the HF. Next, the acceptor solution was withdrawn on-line into the HPLC sample loop connected to the HF and then injected directly into the HPLC system for analysis. We found that the chlorophenols (CPs) could diffuse quickly through two sequential extraction interfaces – the donor phase – SLM and the SLM – acceptor phase – under the assistance of an ultrasonic probe. Ultrasonication provided effective mixing of the extracted boundary layers with the bulk of the sample and it increased the driving forces for mass transfer, thereby enhancing the extraction kinetics and leading to rapid enrichment of the target analytes. We studied the effects of various parameters on the extraction efficiency, viz. the nature of the SLM and acceptor phase, the compositions of the donor and acceptor phases, the fiber length, the stirring rate, the ion strength, the sample temperature, the sonication conditions, and the perfusion flow rate. This on-line extraction method exhibited linearity (r² ≥ 0.998), sensitivity (limits of detection: 0.03–0.05 μg L⁻¹), and precision (RSD% ≤ 4.8), allowing the sensitive, simple, and rapid determination of CPs in aqueous solutions and water samples with a sampling time of just 2 min.     

Synthesis of Novel Chiral Ionic Liquids Based on (−)-Menthyl Isonicotinate

Abstract

Thirteen novel chiral ionic liquids (CILs) containing the (?)-menthyl group can be easily prepared from isonicotinic acid with yields of 35–90%. The properties and characterization of these compounds were discussed and the alternation of optical rotation was analyzed.