The synthesis and biological evaluation of a series of novel 2-COOC_2H_5/COONa substituted 1,5-benzothiazepine derivatives as antimicrobial agents

A series of novel 1,5-benzothiazepine derivatives containing COOC2H5/COONa groups at the C（2）-position were synthesized and evaluated for their antifungal and antibacterial activities by both disc diffusion and minimal inhibition concentration （MIC） methods. Most of the compounds have been shown to have moderate to good antibacterial activity against S. aureus, S. epidermidis and excellent antifungal activity against C. albicans.

Low-cost, green synthesis of highly porous carbons derived from lotus root shell as superior performance electrode materials in supercapacitor

Facile production of high quality activated carbons from biomass materials has greatly triggered much attention presently. In this paper, a series of interconnected porous carbon materials from lotus root shells biomass are prepared via simple pyrolysis and followed by a KOH activation process. The prepared carbons exhibit high specific surface areas of up to 2961 m^2/g and large pore volume～1.47 cm3/g. In addition, the resultant porous carbons served as electrode materials in supercapacitor exhibit high specific capacitance and outstanding recycling stability and high energy density. In particular, their specific capacitance retention was almost 100% after 10500 cycles at a current density of 2 A/g. Remarkabely, the impact of the tailored specific surface areas of various carbon samples on their capacitive performances is systematically investigated.Generally, it was believed that the highly-developed porosity features（including surface areas and pore volume and pore size-distributions）, together with the good conductivity of activated carbon species, play a key role in effectively improving the storage energy performances of the porous carbon electrode materials in supercapacitor.

Syntheses and Crystal Structures of Two New α-Aminophosphonate Derivatives Containing Thieno[2,3-d]pyrimidine

Two new a-aminophosphonate derivatives containing thieno[2,3-d]pyrimidine, diethyl（（（6-ethyl-2-methyl-4-oxothieno[2,3-d]pyrimidin-3 （4H）-yl）amino）（4-methoxyphenyl）methyl） phosphonate （1） and diethyl（（4-bromophenyl）（（6-ethyl-2-methyl-4-oxothieno[2,3-d]pyrimidin-3 （4//）-yl）amino）methyl）phosphonate （2）, have been synthesized by a facial phosphorylated reaction, and their structures were characterized by NMR, IR, HRMS and X-ray single-crystal diffraction. Compound 1 （C21H28N3O5PS, Mr = 465.49） belongs to the orthorhombic system, space group P212121, with a = 10.83653（16）, b = 12.04906（19）, c = 18.0061（3） A, V= 2351.06（6） A3, Z= 4, Dc= 1.315 g/cm3, p = 2.177 mm-1, F（000） = 984.0, the final R = 0.0389 and wR = 0.0985 for all data. Compound 2 （C20H25BrN304PS, Mr = 514.37） belongs to the orthorhombic system, space group P212121, with a = 10.9187（5）, b = 11.9522（4）, c = 17.7667（7） A, V= 2318.60（16） A3, Z = 4, Dc= 1.474 g/cm3,μ = 4.175 mm^-1, F（000） = 1056.0, the final R = 0.0367 and wR = 0.0946 for all data.

Synthesis of cobalt-doped ZnO/rGO nanoparticles with visible-light photocatalytic activity through a cobalt-induced electrochemical method

ZnO is a semiconductor photocatalyst widely applied in photodegradation of organic pollutants and in photoelectric conversion. ZnO exhibits low photocatalytic activity due to poor absorption in the visible region. In this work, a novel cobalt-induced electrochemical growth method was developed to synthesize cobalt-doped ZnO/rGO nanoparticles in an aqueous solution at room temperature. Cobalt-doped ZnO/rGO nanoparticles exhibited wider visible-light absorption band ranging from 400 nm to 700 nm due to cobalt doping. The surface structure of ZnO formed by the cobalt-induced electrochemical method without other ions is suitable for photocatalytic reactions. The cobalt-doped ZnO/rGO nanoparticles were found to exhibit in photodegradation and photo-electrochemical measurements and exhibited enhanced photocatalytic activity under visible-light irradiation.

SYNTHESIS AND CHARACTERIZATION OF MAIN CHAIN AROMATIC LIQUID CRYSTAL COPOLYESTERS WITH X-SHAPED AND ROD-SHAPED MESOGENIC UNITS

A series of main chain liquid crystal aromatic copolyesters with X-shaped and rod-shaped mesogenic units were synthesized via solution condensation polymerizations of 4,4'-(alpha,omega-octanedioyloxy)-dibenzoyl dichlorides with 2,5-bis(p-octanoxy benzoyloxy)-hydroquinone and diphenol. All of the copolyesters showed thermotropic liquid crystalline behaviors through observations using DSC, polarized microscopy and X-ray diffraction. The melting point (T-m) and the isotropization temperature (T-i) change regularly with varying the content of diphenol unit in the copolymers.

SYNTHESIS AND CHARACTERIZATION OF LIQUID CRYSTAL POLYESTERS WITH T-SHAPED TWO-DIMENSIONAL MESOGENIC UNITS(Ⅲ)

A new series of liquid crystal polyesters with T-shaped two-dimensional mesogenic units weresynthesized by melt polycondensation of the diacetates of 2-(4'-alkoxy -phenyl)-hydroquinones with 4,4'-alkylenedioxydibenzoic acid. The polymers were characterized by using polarized microscopy, DSC and X-ray diffraction. It was realized that all the polymers have nematic thermotropic liquid crystallinecharacteristics. The melting temperature (T_m) and isotropization temperature (T_i) of the polymers changeregularly with varying lengths of the alkoxy side group and the length of the alkylene group in the main chainin company with an even-odd effect. The mesophase temperature range also varies regularly with the polymerstructure. It is shown that the mesophase range has been widened.

Syntheses and Crystal Structures of Three Metal Carbonyl Complexes Based on Pyridyl Side Chain Functionalized Tetramethylcyclopentadienyl Ligand

Thermal treatment of the pyridyl side chain functionalized tetramethyl cyclopen- tadiene C5Me4CH2（C5H4N） with Fe（CO）5, Ru3（CO）12 and Mo（CO）6 in refluxing xylene respectively gave the corresponding dinuclear metal carbonyl complexes 1～3. These complexes have been characterized by elemental analysis, IR and IH NMR spectra. The molecular structures of 1～3 were determined by X-ray diffraction analysis.

Microwave Synthesis of Ce/BiVO₄Nanocomposites Photocatalyst and Their Photocatalytic Properties

Ce/BiVO4 nanocomposites photocatalyst was synthesized by direct feeding microwave synthesis method, using bismuth nitrate (Bi (NO3)3·5H2O), cerium?nitrate hexahydrate (Ce (NO3)3·6H2O) and ammonium metavanadate (NH4VO3) as raw material and sodium dodecyl sulfate (SDS) as surfactant. The X-ray diffractometer (XRD) and the scanning electron microscopy (SEM) technology were used to characterize the Ce/BiVO4 nanocomposites. We investigated the photocatalytic activity of the as-prepared photocatalyst, and methyl orange was used as organic pollutant. The results show that the Ce/BiVO4 nanocomposite was a good photocatalyst under visible light. In 100 ml of 5 mg/L methylene orange solution, when the catalyst calcined at 673 K was 0.1 g, hydrogen peroxide was 0.5 ml, pH was 2.0, and the degradation ratio of catalyst for methylene orange reached 90.26% within 70 min.

Rational modulation of electronic structure in PtAuCuNi alloys boosts efficient electrocatalytic ethanol oxidation assisted with energy-saving hydrogen evolution

Compared to conventional electrocatalytic water splitting,electrocatalytic ethanol oxidation reaction(EOR)along with hydrogen production is considered a more energy-efficient strategy.Herein,we prepared a type of novel quaternary alloy catalyst(PtAuCuNi@NF)that exhibits excellent activity for EOR(0.215 V at 10 mA cm^(-2))and hydrogen evolution reaction(HER)(7 mV at 10 mA cm^(-2)).Experimental results demonstrated that both Cu and Ni modulated the electronic environment around Pt and Au.The electron-rich active center facilitates the rapid adsorption and dissociation of reactants and intermediates for both EOR and HER.Impressively,in the ethanol-assisted overall water splitting(E-OWS),a current density of 10 mA cm^(-2)was achieved at 0.28 V.Moreover,an advanced acid-base self-powered system(A-Bsps)that can achieve a self-powered voltage of 0.59 V was assembled.Accordingly,the self-driven hydrogen production with zero external power supply was realized by integrating A-Bsps with the E-OWS equipment.The interesting results can provide a feasible strategy for designing and developing advanced nanoalloy-based materials for clean energy integration and use in various fields.

Phase Selectively Soluble Dendritic Derivative of 4-(Dimethylamino)- pyridine: An Easily Recyclable Catalyst for Baylis-Hillman Reactions

A new thermomorphic catalytic system for the Baylis-Hillman coupling of aromatic aldehydes with a, β-unsaturated ketone has been described, in which the alkyl-functionalized dendritic catalyst preferred to dissolve in non-polar organic layer in the thermomorphic biphasic system, leading to easy separation of the catalyst from the polar products by changing the temperature of the system at end of the reaction.

Luminescent Properties of Mercury-taining Diethynylfluorene Derivatives

Excited state structures and spectroscopic properties of mercury（ 11 ） complexes, Hg-TFT（1） and its electronwithdrawing substituents Hg-TFOT （ 2 ）, Hg-TFCNT （ 3 ）, where TFT = dietbynylfluorenyl, TFOT = diethynylfluorenone, and TFCNT = diethynyl-[9-（dicyanomethylene） fluorene], were studied using singlet excitation configuration interaction（CIS） and time-dependent density functional theory（TDDFT） methods. The results of the theoretical calculations indicate that the electron-withdrawing substitutions lead to a significant decrease in the energy gap between the ground state and the first excited states. In the case of Hg-TFCNT, the second singlet excited state （S2 ） may contribute to the luminescence because of its large S1-S2 separation.

Durable poly(binaphthyl-co-p-terphenyl piperidinium)-based anion exchange membranes with dual side chains

Building well-developed ion-conductive highways is highly desirable for anion exchange membranes(AEMs).Grafting side chain is a highly effective approach for constructing a well-defined phaseseparated morphological structure and forming unblocked ion pathways in AEMs for fast ion transport.Fluorination of side chains can further enhance phase separation due to the superhydrophobic nature of fluorine groups.However,their electronic effect on the alkaline stability of side chains and membranes is rarely reported.Here,fluorine-containing and fluorine-free side chains are introduced into the polyaromatic backbone in proper configuration to investigate the impact of the fluorine terminal group on the stability of the side chains and membrane properties.The poly(binaphthyl-co-p-terphenyl piperidinium)AEM(QBNp TP)has the highest molecular weight and most dimensional stability due to its favorable backbone arrangement among ortho-and meta-terphenyl based AEMs.Importantly,by introducing both a fluorinated piperidinium side chain and a hexane chain into the p-terphenyl-based backbone,the prepared AEM(QBNp TP-QFC)presents an enhanced conductivity(150.6 m S cm^(-1))and a constrained swelling at 80℃.The electronic effect of fluorinated side chains is contemplated by experiments and simulations.The results demonstrate that the presence of strong electro-withdrawing fluorine groups weakens the electronic cloud of adjacent C atoms,increasing OH^(-)attack on the C atom and improving the stability of piperidinium cations.Hence QBNp TP-QFC possesses a robust alkaline stability at 80℃(95.3%conductivity retention after testing in 2 M Na OH for 2160 h).An excellent peak power density of 1.44 W cm^(-2)and a remarkable durability at 80℃(4.5%voltage loss after 100 h)can be observed.

3D macropore carbon-vacancy g-C_(3)N_(4) constructed using polymethylmethacrylate spheres for enhanced photocatalytic H_(2) evolution and CO_(2) reduction

Metal-free g-C_3N_4 is widely used in photocatalytic reactions owing to its suitable band structure.However, it has low specific surface area and insufficient absorbance for visible light, and its photoexcited carriers have high recombination rates. In this study, the 3 D macropore C-vacancy g-C_3N_4 was prepared through a facile one-step route. Polymethylmethacrylate is used as a template to increase the surface reaction sites of g-C_3N_4 and extend its visible-light range. Compared to unmodified g-C_3N_4, the H2 production and CO_2 reduction rates of the fabricated g-C_3N_4 significantly improved. The special pore structure significantly improved the light utilization efficiency of g-C_3N_4 and increased the number of surface-active sites. The introduction of C-vacancy extended the absorption band of visible-light and suppressed the carrier recombination. The newly developed synthesis strategy can improve solar energy conversion efficiency and potentially modifies g-C_3N_4.

A Healable and Mechanically Enhanced Composite with Segregated Conductive Network Structure for High‑Efficient Electromagnetic Interference Shielding

It is still challenging for conductive polymer composite-based electromagnetic interference(EMI)shielding materials to achieve long-term stability while maintaining high EMI shielding effectiveness(EMI SE),especially undergoing external mechanical stimuli,such as scratches or large deformations.Herein,an electrostatic assembly strategy is adopted to design a healable and segregated carbon nanotube(CNT)/graphene oxide(GO)/polyurethane(PU)composite with excellent and reliable EMI SE,even bearing complex mechanical condition.The negatively charged CNT/GO hybrid is facilely adsorbed on the surface of positively charged PU microsphere to motivate formation of segregated conductive networks in CNT/GO/PU composite,establishing a high EMI SE of 52.7 dB at only 10 wt%CNT/GO loading.The Diels–Alder bonds in PU microsphere endow the CNT/GO/PU composite suffering three cutting/healing cycles with EMI SE retention up to 90%.Additionally,the electrostatic attraction between CNT/GO hybrid and PU microsphere helps to strong interfacial bonding in the composite,resulting in high tensile strength of 43.1 MPa and elongation at break of 626%.The healing efficiency of elongation at break achieves 95%when the composite endured three cutting/healing cycles.This work demonstrates a novel strategy for developing segregated EMI shielding composite with healable features and excellent mechanical performance and shows great potential in the durable and high precision electrical instruments.

Carbon nanotubes-supported palladium nanoparticles for the Suzuki reaction in supercritical carbon dioxide: A facile method for the synthesis of tetrasubstituted olefins

A facile and efficient method for the synthesis of tetrasubstituted olefins in supercritical carbon dioxide was developed by using carbon nanotubes-supported palladium nanoparticles (Pd/CNTs) as the catalyst. Compared with common Pd/C, Pd/CNTs could more effectively catalyze the reaction of dibromo-substituted olefins with boronic acids, affording the corresponding tetrasubstituted olefins with moderate to good yields. This environmentally benign route with an easy-to-handle catalyst provides an appealing alternative to the currently available methods.

Synthesis and antitumor activity of α-aminophosphonate derivatives containing thieno[2,3-d]pyrimidines

Two series of thieno[2,3-d]pyrimidine derivatives were designed and synthesized, in which bioactive α-aminophosphonate subunits were introduced at the N3 position through an N-N bond connection. The in vitro cytotoxic activity of the novel compounds was tested against human esophageal carcinoma cells （EC109）, human hepatocarcinoma cells （HepG2）, human gastric carcinoma cells （MGC-803）, respectively, by the MTT method. The evaluation results revealed that compounds fimb, 6mf, 6mg, 6rid and 6nh exerted the most potent inhibition against HepG2, MGC-803 and EC109 cells, respectively. In particular, compound 6rag presented excellent inhibitory effect against HepG2 （91.2%） and MGC-803 （94.4%） cells.

Highly efficient one-pot,three-component synthesis of1,5-benzodiazepine derivatives

A general, mild and efficient protocol for the synthesis of ethyl 4-methyl-2-（thiophen）-2,5-dihydro-1,5- benzodiazepine-3-carboxylate is achieved for first time using H3PMo12O40 in ethanol at 0 ℃ by a one- pot, three-component condensation of various thiophene aldehydes, substituted o-phenylenediamines and ethyl acetoacetate. Compared with the conventional synthesis method, this procedure has the advantages of convenient operation, excellent yields, and environmentally benign. A plausible formation mechanism has been proposed. The structure of the products is characterized by1H NMR, IR, MS and elemental analysis.

Synthesis of polycyclic spiro-fused indolines via IBX-mediated cascade cyclization

We report a 2-iodoxybenzoic acid(IBX)-mediated intarmolecular oxidative spiro-fused tandem cyclization reaction of tryptophan analogs bearing an N-arylamides side-chain to rapidly afford polycyclic spiroindolines featuring multiple stereocenters including a quaternary stereocenters under mild reaction conditions.Among them,a novelty azaphosphol idine-containing spiroindoline compound is synthesized for the first time.It may open the door to azaphos pholidine-containing spiroindoline compound of potential interest in synthetic and medicinal chemistry.A plausible mechanism is proposed.