A visible-light-induced three-component sulfonylation/aminoalkylation of alkenes has been achieved to furnish a series of sulfonated 4-amino-chroman, 4-amino-tetrahydroquinoline, and 5-amino-dihydrobenzo[b]oxepine derivatives by using eosin Y as a photocatalyst. This metal-free synthesis strategy involves in situ imine condensation and visible-light-promoted C-S/C-C triple domino bond formation by using readily ortho-allyloxy-benzaldehydes, anilines, and sodium benzenesulfinates as substrates. This protocol features mild reaction conditions, broad substrate scopes, and good functional group compatibility, and they are therefore of potential practical value for the synthesis and structural modification of biologically active chroman derivatives.

Porous carbon was successfully prepared from Cynomorium songaricum waste via a melamine-assisted KOH activation strategy. Systematic investigation of melamine content revealed its significant impact on the material's morphology and electrochemical properties. The optimal carbon structure exhibited enhanced specific surface area (increasing from 1712.9 to 2448.0 m2 g- 1) and nitrogen content (rising from 1.41 % to 2.75 %). Supercapacitors fabricated with the prepared carbon materials demonstrated notable specific capacitance, achieving 369.3 F g-1 (at 1.0 A g-1) in 6.0 mol L-1 KOH. Furthermore, the carbon-based supercapacitors exhibited an energy density of 10.45 Wh kg-1 (at 300 W kg -1). After 60,000 charge-discharge cycles, the capacitance decreases by less than 4 %, while the Coulombic efficiency remains at 100 %. This study highlights a simple, sustainable, and environmentally friendly approach to repurposing waste from medicinal plants.

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There remains a critical need for the detection of bacterial contamination to ensure public health. In this work, we developed a pH meter-assisted biosensor based on glucose oxidase (GOx)-conjugated magnetic zeolitic imidazolate framework-8 (mZIF-8) for on-site evaluation of bacterial contamination. The mZIF-8/GOx conjugate was produced from the electrostatic interaction between GOx and mZIF-8 and was demonstrated to inhibit GOx activity without protein denaturation. However, the presence of bacteria can cause the release of GOx from the mZIF-8 surface through competitive binding with mZIF-8, resulting in the recovery of GOx activity, which converts glucose into gluconic acid and provides an amplified pH signal. This finding allows the mZIF-8/GOx conjugate to be a biosensor for on-site detection of bacterial contamination with a pH meter as a readout. Benefiting from the magnetic separation property of mZIF-8, greatly enhanced sensitivity and precision have been achieved with detection limits of 10 cfu/mL for Escherichia coli and 30 cfu/mL for Staphylococcus aureus. Meanwhile, the flexibility of this biosensor was validated by quantitative analysis of mixed bacteria including Gram-positive and Gram-negative bacteria with desired performances. The accurate bacterial determination in contaminated drinking water samples demonstrates the applicability of this biosensor for reliable home monitoring of water quality.

Explorations of green and efficient methodologies for the utilization of traditional Chinese medicine residues are very important to the development of traditional Chinese medicine as well as environment protection. As an important traditional Chinese medicine, 3,000-3,500 tons of Cistanches Herba raw materials were used every year to produce 200 million bottles of oral liquids, accompanied with large amount of solid wastes annually. Considering the abundant carbon resources as well as metal ions contained in Cistanches Herba, an efficient method for the synthesis of porous carbon was designed by employing Cistanches Herba residues as precursor and pre-carbonization/KOH activation as method, affording N,O co-doped porous carbon (CHC-350-800-3) with high specific surface area (2767.2 m2 g−1). With CHC-350-800-3, a supercapacitor electrode was prepared, which displays both high capacitance (360.26 F g–1 at 1.0 A g–1) and high-rate capability (53% of capacitance retention at 100 A g–1) in 6.0 M L−1 KOH electrolyte. Importantly, this CHC-350-800-3-based supercapacitor also displays high energy density (21.72 Wh kg-1 at 250 W kg -1) as well as high cycling stability (100% of capacitance retention after 13000 cycles) in 1.0 M L−1 H2SO4 electrolyte.

We reported a versatile protocol to chemodivergently construct significant heterocyclic scaffolds of benzothiadiazin-3-one 1-oxides and benzisothiazol-3-ones by visible light-promoted photocatalysis. This substrate-dependent chemoselective strategy enables N-(2-mercaptophenyl)-N'-substituted ureas through the N-S bond coupling/oxidation cascade to selectively produce benzothiadiazin-3-one 1-oxides; however, the transformation of 2-mercaptobenzamides only occurs via N-S bond coupling to access benzisothiazol-3-ones with moderate to good yields. This strategy features mild conditions, excellent chemoselectivity, and functional group compatibility, which has potential applications in organic and medicinal chemistry.

Cistanches herba residues are successfully employed as starting materials to prepare porous carbon through pre-carbonization and KOH activation method. The effects of pre-carbonization, KOH activation, and pre-carbonization temperature are investigated. The optimal structure of as-prepared carbon has abundant micropores, high specific surface area (2767.2 m2 g-1), good affinity for electrolyte, and high content of self-doped O (29.09%) and N (1.37%). The supercapacitors constructed with the as-prepared carbon materials are able to exhibit good specific capacitance of 360.26 F g-1 at 1.0 A g-1 and 191.3 F g-1 at 100 A g-1 in 6.0 mol L-1 KOH electrolyte. Moreover, the as-prepared carbon-based supercapacitors also display good energy density of 21.72 Wh kg-1 (at 250 W kg -1) and achieve 100% specific capacitance retention after 13,000 cycles at 10 A g-1 in 1.0 mol L-1 H2SO4 electrolyte. Overall, this research presents a new avenue for high-value uti-lization of traditional Chinese medicine residues.(c) 2023 Elsevier B.V. All rights reserved.

A new lanthanide complex is designed and obtained based on the ligand of 2,4,5,6-tetrafluoroisophthalic acid (H2TFPA) and 1,10-phenanthroline (phen) under mild hydro(solvo)thermal conditions. The new complex has the molecular formula of [Tb2(TFBA)3(phen)2(H2O)2]n (TbMOF) and it is characterized in detail. It is confirmed that TbMOF shows high water stability, thermal stability, acid and alkali resistance. The experimental results show that TbMOF solid state sample shows a luminescence decay lifetime of 0.448 ms, and a high luminescence quantum yield (QY) of 38.15%. Interestingly, studies showed that TbMOF is an excellent sensor for detecting antibiotics of ciprofloxacin (CIP). In addition, the limit of detection (LOD) for CIP is an extremely high sensitivity value of 0.17 ppm. In the concentration range of 1.0 x 10-7-1.0 x 10-6 M, CIP shows an excellent linear relationship with the luminescence intensity of TbMOF. Most importantly, test paper based on TbMOF and fiber material of filter paper is fabricated, which is a strongly anti-interference, selective, sensitive, portable and visible to the naked eyes sensing device towards CIP in real samples of human urine, tap water, and lake water.

A general and facile visible-light mediated protocol for the synthesis of 2-arylamino-5-aryl-1,3,4- thiadiazoles via one-pot condensation and intramolecular C–S coupling cascade reaction has been developed. This protocol is mild, practical, metal-free and exogenous oxidant-free, and only involves Eosin Y as photocatalyst using oxygen as the sole terminal oxidant. This protocol exhibits synthetic simplicity, broad scope of substrates, and excellent functional group compatibility. Gram-scale synthesis can be also facilitated with a satisfactory yield, which opens up the possibility of practical applications.

社团作为中学课堂教学的重要补充形式之一,在培养学生综合能力方面具有不可替代的优势.近年来,学者们对中学社团的研究热度呈上升趋势,主要从中学社团的功能、建设与管理中的问题以及对有关问题的应对策略三方面进行研究.文中对这三方面的研究进行了综合评述,并结合化学社团提出了一些思考和建议.

9,9-Bis(4-iodophenyl)xanthene (BIPX) was prepared in good yield by the sequential diazotization–iodination of 9,9-bis(4-aminophenyl)xanthene with a KI/NaNO2/p-TsOH system in acetonitrile at room temperature. A series of novel aromatic polyamides (PAs) were prepared by a carbonylation polymerization of BIPX, aromatic diamines and carbon monoxide in DMAc with Pd(PPh3)2Cl2 as the catalyst in the presence of PPh3 and 1,8-diazabicyclo[5,4,0]-7-undecene (DBU). The resulting PAs bearing inherent viscosity of 0.65–0.75 dL/g were amorphous and readily soluble in organic polar solvents such as NMP, DMF, DMAc, DMSO and Py. These new PAs exhibited good thermal stability with glass-transition temperature of 241–359 °C, 10% weight loss temperature of 480–492 °C and char yield of 47.8–56.7% at 800 °C in nitrogen. Meanwhile, all obtained PAs exhibited low water uptake of 0.98–2.37%, and their transparent, tough and flexible films presented high optical transparency with a cutoff wavelength in the 322–370 nm range and had the tensile strength in the range of 73.4–83.4 MPa, elongation at breakage of 6.7–13.8% and tensile modulus of 1.6–2.2 GPa, respectively.

Poly(ethylene terephthalate)/poly(ethylene-octene) (PET/POE) blends compatibilized with glycidyl methacrylate grafted poly(ethylene-octene) (mPOE) were prepared by melt blending using a twin screw extruder. The effects of the molecular weight of the PET matrix on the morphology and properties of the PET/POE/mPOE blends are described. The results of the SEM analysis showed that the average particle diameters of the dispersed phase decreased with an increase in the PET molecular weight. The results of the mechanical property tests showed that the notch Charpy impact strength and elongation at break of the PET/POE/mPOE blends improved with an increase in the PET molecular weight. However, the flexural strength, flexural moduli and tensile strength were nearly unchanged. The crystallization rate of PET in the PET/POE/mPOE blends improved with decreasing PET molecular weight.

我们以传统文化作为思政教育融入高中化学教学的切入点,将醋文化融入到高中化学校本课程开发中,以此提高学生的学习兴趣,促进学生对此部分所涉及知识的掌握与融合,培养学生的文化自信及化学学科核心素养.

A new aromatic unsymmetrical diamine containing imidazolyl and trifluoromethyl groups, 1,2-bis(4-aminophenyl)-4,5-bis(4-trifluoromethylphenyl)-1H-imidazole was synthesized. A series of novel fluorinated polyimides (PIs) were prepared by polycondensation of this diamine monomer with various aromatic dianhydrides via one-step process. The resulting PIs bearing inherent viscosities of 0.45–0.61 dL/g were amorphous and readily soluble in organic polar solvents such as NMP, DMF, DMAc, THF, and CHCl3. These new PIs exhibited good thermal stability with 10% weight loss temperatures of 530–560°C and char yields of 61–65% at 800°C in nitrogen, as well as good flame retardancy with limited oxygen index value of 40.6–42.8, and outstanding hydrophobicity with the contact angle of 85.2–93.5°. Meanwhile, all the obtained PIs exhibited low water uptake of 0.30–0.53%, strong UV-vis absorption in the range of 267–310 nm in DMF solution, and their films presented high optical transparency with a cut-off wavelength in the 355–392 nm range. Except for the PI film derived from pyromellitic dianhydride, the other PI films had the tensile strength in the range of 53.2–74.1 MPa, elongation at breakage of 6–15%, and tensile modulus of 1.0–1.5 GPa, respectively.

Taking “the production of invisible ink” as the theme and starting from the magical phenomena in life, the special review teaching of “acid and base” in junior high school chemistry is carried out. Through students’ personal understanding of the principle, hands-on production, display and application of “invisible ink”, students can better master the acidity and alkalinity of the solution and the discoloration of the indicator, and understand the concept, chemical properties and chemical reactions of acid and alkali. Driven by multiple tasks, students’ practical ability and problem-solving ability are continuously enhanced, their awareness of scientific inquiry and discipline core literacy are continuously improved, and they can personally feel the close relationship between chemistry and life and the charm of chemistry.

在当前的大学教育形式下,教师不仅要引导大学生学习基础知识、提升基本实验操作技能,更要重视思想政治素质教育,以达到培养大学生严谨求实的科研态度、树立正确的价值观及培养强烈的社会责任感.本文以有机化学课程中"对映异构"知识内容作为教学设计案例,从学习目标设置、教学内容与思政元素的融合及教学活动的开展等方面探讨了课程思政在对映异构教学中有机融合的教学设计思路与方法.

A novel visible-light-catalyzed oxidative N-S bond formation for the synthesis of 3,5-disubstituted 1,2,4-thiadiazoles has been developed. This protocol features a metal-free approach, green oxidant, room temperature process, broad substrate scope, good functional group tolerance, excellent yields and a one-pot reaction without the isolation of the intermediates. [GRAPHICS] .

This feature article details the progress of transition metal-catalyzed stereoselective sp2 and sp3 C-H activation and silylation in the synthesis of chiral organosilicon compounds, and the asymmetric C-H silylation includes intramolecular cyclizing silylation and intermolecular silylation. The silylating reagents include monohydrosilanes, dihydrosilanes, silacylcobutanes and disilanes. In general, catalytic systems include a transition metal salt as the catalyst and a chiral ligand. No external chiral ligand is required in some cases where the chiral substrates act as the source of chirality. Many kinds of silylated compounds with central, axial, planar, or helical chirality have been constructed via C-H activation by asymmetric rhodium, iridium or palladium catalysis. Some pharmacophores and material building blocks were successfully introduced into the target molecules. Some silylated products proved to be useful in medicinal chemistry, synthetic organic chemistry, and materials science. Besides reaction development, mechanisms for stereoselective C-H activation and silylation are also discussed.

具有高能量密度、循环寿命长、体积小、重量轻、记忆效应少、污染少的锂离子电池,已被公认为未来用于储存电力最有效的方法.负极材料作为锂离子电池的重要组成部分,许多课题组都一直致力于开发高性能负极材料的研究.系统讨论了几种常研究的纳米结构负极材料(包括碳、合金、过渡金属氧化物和硅)的优缺点和发展方向.