Performance enhancement and active sites identification of Cu-Cd bimetallic oxide derived catalysts for electrochemical CO_(2) reduction

The development of earth-abundant electrocatalysts with high performance for electrochemical CO_(2)reduction(ECR)is of great significance.Cu-based catalysts have been widely investigated for ECR due to their unique ability to generate various carbonaceous products,but directing selectivity toward one certain product and identifying the real active sites during ECR are still full of challenge.Here,after the incorporation of CdO into CuO,the Cu_(0.5)Cd_(0.5)-O catalyst achieves a 10.3-fold enhancement for CO selectivity in comparison with CuO,and a CO faradic efficiency nearly 90%with a current density around20 mA cm^(-2)could maintain at least 60 h.Interestingly,a wide CO/H_(2)ratio(0.07-10)is reached on Cu_(x)Cd_(1-x)-O catalysts by varying the Cu/Cd ratio,demonstrating the potential of syngas production using such catalysts.The results of ex situ XRD,XPS,and in situ Raman reveal that the real active sites of Cu_(0.5)Cd_(0.5)-O catalysts for CO production during ECR reaction are the reconstructed mixed phases of CuCd alloy and CdCO_(3).In situ FTIR and theoretical calculations further implicate the presence of Cd related species promotes the CO desorption and inhibits the H_(2)evolution,thus leading to an enhanced CO generation.

Development of biofertilizers for sustainable agriculture over four decades(1980-2022)

The application of biofertilizers is becoming an inevitable trend to substitute chemical fertilizers for sustainable agriculture.To better understand the development of biofertilizers from 1980 to 2022,we used bibliometric mining to analyze 12,880 journal articles related to biofertilizer.The network cooccurrence analysis suggested that the biofertilizers research can be separated into three stages.The first stage(1980-2005)focused on nitrogen fixation.The second stage(2006-2015)concentrated on the mechanisms for increasing plant yield.The third stage(2016-2022)was the application of biofertilizers to improve the soil environment.The keyword analysis revealed the mechanisms of biofertilizers to improve plant-growth:biofertilizers can impact the nutritional status of plants,regulate plant hormones,and improve soil environments and the microbiome.The bacteria use as biofertilizers,included Pseudomonas,Azospirillum,and Bacillus,were also identified through bibliometric mining.These findings provide critical discernment to aid further study of biofertilizers for sustainable agriculture.

In-situ constructing Cu_(1)Bi_(1)bimetallic catalyst to promote the electroreduction of CO_(2)to formate by synergistic electronic and geometric effects

Electrochemical CO_(2)reduction to formate is a potential approach to achieving global carbon neutrality.Here,Cu1Bi1bimetallic catalyst was prepared by a co-precipitation method.It has a ginger like composite structure(CuO/CuBi_(2)O_(4))and exhibited a high formate faradaic efficiency of 98.07%at–0.98 V and a large current density of–56.12 mA.cm^(-2)at–1.28 V,which is twice as high as Bi2O3catalyst.Especially,high selectivity(FE^(–)_(HCOO)>85%)is maintained over a wide potential window of 500 mV.In-situ Raman measurements and structure characterization revealed that the reduced Cu1Bi1bimetallic catalyst possesses abundant Cu-Bi interfaces and residual Bi-O structures.The abundant Cu-Bi interface structures on the catalyst surface can provide abundant active sites for CO_(2)RR,while the Bi-O structures may stabilize the CO_(2)^(*–)intermediate.The synergistic effect of abundant Cu-Bi interfaces and Bi-O species promotes the efficient synthesis of formate by following the OCHO^(*)pathway.

Regulating the coordination environment of Ru single-atom catalysts and unravelling the reaction path of acetylene hydrochlorination

In this work,DFT calculations were used firstly to simulate the nitrogen coordinated metal single-atom catalysts(M-N_(x)SACs,M=Hg,Cu,Au,and Ru) to predict their catalytic activities in acetylene hydrochlorination.The DFT results showed that Ru-N_(x)SACs had the best catalytic performance among the four catalysts,and Ru-N_(x)SACs could effectively inhibit the reduction of ruthenium cation.To verify the DFT results,Ru-N_(x)SACs were fabricated by pyrolyzing MOFs in-situ spatially confined metal precursors.The N coordination environment could be controlled by changing the pyrolysis temperature.Catalytic performance tests indicated that low N coordination number(Ru-N_(2),Ru-N_(3))exhibited excellent catalytic activity and stability compared to RuCl_(3)catalyst.DFT calculations further revealed that Ru-N_(2)and Ru-N_(3)had a tendency to activate HCl at the first step of reaction,whereas Ru-N4tended to activate C_(2)H_(2).These findings will serve as a reference for the design and control of metal active sites.

Increase of chiral sensing ability in host-guest chemistry by magnetic anisotropy

Enantiomeric molecules generally play distinct functions in chemistry,biology,and pharmacology.Similar physical and chemical properties of chiral analytes lay difficulty in discrimination and quantification of the enantiomers.We report herein an efficient approach of increasing the chiral sensing ability ofβ-cyclodextrin(β-CD),a widely used host molecule,in the hostguest chemistry by magnetic anisotropy.A rigid and chiral lanthanide binding tag was attached to theβ-CD to amplify the changes of nuclear magnetic resonance(NMR)signals in the host-guest recognition process.The installation of the paramagnetic lanthanide ion inβ-CD greatly enhances the enantiomeric discrimination up to 30-fold in comparison with the diamagneticβ-CD reference.In addition,the magnitude of the paramagnetic effects is tunable according to the diverse range of paramagnetic strength of the lanthanide series.The reported method significantly increases the chiral sensing ability ofβ-CD,which can be applied to other host molecules.The transferred paramagnetic effects,pseudocontact shifts(PCSs)and paramagnetic relaxation enhancements(PREs),from the host to the guest molecules,are valuable structural restraints to determine the absolute stereochemistry of the chiral analytes.The strategy does not need modification of the analytes and is complementary to the reported analytical methods that rely on the functionalization of the chiral analytes.

Bis(trifluoromethylsulfonyl)phenylamines as Internal Donors for Ziegler-Natta Polymerization Catalysts

Several bis（trifluoromethylsulfonyl）phenylamines have been synthesized and used as internal donors for the preparation of heterogeneous Ziegler-Natta catalysts for propylene polymerization. These new cata- lysts are highly active and stereospecific in combination with an external donor for the polymerization of propylene. The activity of these catalysts is dramatically influenced by the electronic capability of the phenyl substituents on the sulfonyl phenylamines. Therefore, the performances of the catalysts can be modified by adjusting the electronic property of the phenyl substituents of the sulfonyl phenylamines.

Crystal Structure and Luminescence Property of Lanthanide Complexes with 2-Fluorobenzoic Acid and 2,2′-Bipyridine

The two compounds of [Ln（2-FBA）3·2,2＇-bpy ]2（2-FBA = 2-fluorobenzoato, 2,2＇-bpy = 2,2＇-bipyridine, Ln = Eu（1 ）, Dy（2）） were synthesized and their structures were determined by X-ray diffraction method. Crystallized complexes 1 and 2 are isomorphous, monoelinie system with P21/n space group. The two complexes are binuclear molecule with an inversion center. The two lanthanide ions are linked by four bridged 2-FBA ligands and each lanthanide ion is further bonded to one chelated bidentate 2-FBA ligand and one 2,2＇-bipyridine molecule. The coordination number of metal ion is eight. The europium complex exhibits strong red fluorescence. ^5D0→^7Fj（j = 1 - 4） transition emission of Eu^3＋ ion was observed.

A new sesquiterpene from the roots of Vladimiria souliei

A new sesquiterpene, named vladimenal （1）, was isolated from the roots of Vladimiria souliei. The structure was elucidated on the basis of spectroscopic analysis.

Synthesis,Crystal Structure,DFT Studies and Biological Activity of a Novel Schiff Base Containing Triazolo[4,3-a]pyridine Moiety

The novel Schiff base（E）-8-chloro-NA-（4-（dimethylamino）benzylidene）-[1,2,4]triazolo[4,3-a]pyridine-3-carbohydrazide was synthesized and characterized by ^1H NMR,MS,elemental analysis and X-ray diffraction.The compound crystallizes in the monoclinic space group P2_1/c with a = 7.091（2）,b = 10.750（3）,c = 21.380（6） A,β = 96.299（6）°,V = 1619.7（8） A^3,Z = 4 and R = 0.0351.Theoretical calculation of the title compound was carried out with the B3LYP/6-31 G basis set.The frontier orbital energy and atomic net charges were discussed.It is found that the experimental data show good agreement with the calculated values.And the compound exhibits good antifungal activity against Stemphylium lycopersici（Enjoji） Yamamoto.

Enhancement of RNAi by a small molecule antibiotic enoxacin

Dear Editor, RNAi has become a mainstream molecular tool for assessing the functions of genes in mammalian cells . Large-scale RNA interference-based analyses are often complicated by false positive and negative hits due to off-target effects and interferon response , which can be attributed at least in part to the use of high concentrations of siRNA. Lowering the amounts of siRNAs and shRNAs can effectively and expediently mitigate the off-target effect and interferon response .

Building the Pharmacophore Model of HIV-1 Integrase Strand Transfer Inhibitors and Studying Their Inhibition Mechanism

The replication of HIV-1 requires the integration of its cyclic DNA into host DNA by HIV-1 integrase （IN）, which includes two important reactions, 3＇-processing and strand transfer, both catalyzed by HIV-1 IN. Disrupting either of the reactions will fulfill the purpose of inhibiting the replication of HIV-1. In this paper, pharmacophore modeling and molecular docking are employed to investigate the inhibition mechanism of the HIV-1 IN strand transfer inhibitors （INSTIs）. Based on the results, we suggest that the inhibition mechanism of INSTIs involves the inhibitor chelating the cofactors Mg2＋ and its forming hydrogen bonds with some crucial residues adjacent to the DDE active center.

Synthesis and Herbicidal Activity of Novel 5-Substituted Benzenesulfonylureas

Sulfonylurea herbicides have been widely used because of their low application rates, good crop sdeetivities and low mammalian toxicities. However, some sulfonylureas might persist unfavourably in the environment with residual problems. In order to look for ecologically safer and environmentally benign sulfonylureas, and on keeping the pyrimidine ring being monosubstitated, 15 novd C5-monosubstituted benzenesulfonylurea compounds were synthesized. The structures of all the compounds synthesized were confirmed by demental analysis and ^1H NMR. Preliminary herbicidal activities of these new sulfonylurea compounds were determined by ALS screening （ in vitro） and pot bioassay experiments（ in vivo）. The herbicidal results show that some novel sulfonylureas are comparable to commercial Foramsulfuron and Monosulfuron.

Synthesis and Herbicidal Activity of Novel Sulfonylureas Containing Thiadiazol Moiety

Thirteen novel sulfonylureas containing thiadiazole moiety were synthesized in a two-step reaction. Their structures were determined using IR, ^1H NMR, HRFTMS, and elemental analysis. Herbicidal activities of these compounds were determined in the green house bio-assay. The results show that four compounds among them exhibit some activity toward four tested herbs.

Synthesis, Crystal Structure and Biological Activity of 1,5-Bis(4-methoxyphenyl)-3-(4-methyl-1,2,3-thiadiazol-5-yl)pentane-1,5-dione

The title compound 1,5-bis（4-methoxyphenyl）-3-（4-methyl-1,2,3-thiadiazol-5-yl）-pentane-1,5-dione （C22H22N2O4S, Mr=410.49） has been synthesized by the reaction of 4-methyl-1,2,3-thiadiazole-5-carbaldehyde with 4-methoxyacetophenone, and its structure was characterized by IR, 1H NMR, H RMS, elemental analysis and single-crystal X-ray diffraction. The crystal of the title compound belongs to monoclinic, space group P21/c with a=11.159（3）, b=9.002（3）, c=20.192（6）, β=93.393（5）°, Z=4, V=2024.6（10） 3 , Dc=1.347 g/cm3 , μ=0.191 mm-1 , F（000）=864, R=0.0333 and wR （I〉2σ （I））=0.0840. In this molecule, the 1,2,3-thiadiazol ring is nearly vertical with both phenyl rings, and intermolecular weak hydrogen bonds of C-H…O and C-H…N types together with π-π stacking interactions and interactions between S（1）…N（2） are observed. The above three kinds of interactions extend the molecules into a two-dimensional layer framework. The preliminary biological test showed that the title compound had fungicidal activity.

Design, Synthesis, and Biological Activity of Novel Aromatic Amide Derivatives Containing Sulfide and Sulfone Substructures

In recent years,the damage caused by soil nematodes has become increasingly serious;however,the varieties and structures of the nematicides available on the market are deficient.Fluopyram,a succinate dehydrogenase inhibitor(SDHI)fungicide developed by Bayer AG in Germany,has been widely used in the prevention and control of soil nematodes due to its high efficiency and novel mechanism of action.In this paper,two series of novel target compounds were designed and synthesized with nematicidal and fungicidal fluopyram as the molecular skeleton in order to introduce sulfide and sulfone substructures.The structures were identified and characterized by 1H nuclear magnetic resonance(NMR),13C NMR,and high-resolution mass spectrometer(HRMS).The bioassays revealed that most of the compounds showed excellent nematicidal activities at 200 lgmL-1 in comparison with fluopyram,while the nematode mortality rate dropped sharply at 100μg·mL-1,except for compounds I-11 and II-6.In terms of fungicidal activity,compound I-9 was discovered to have an excellent inhibitory rate,and a molecular docking simulation was performed that can provide important guidance for the design and exploration of efficient fungicidal lead compounds.

Binding of Pyrene to Different Molecular Weight Fractions of Dissolved Organic Matter:Effects of Chemical Composition and Steric Conformation

The binding constant（KDOM） of pyrene onto different molecular weight（Mw） fractions of a dissolved organic matter（DOM） extract from an estuarine sediment was measured via a fluorescence quenching method,and the possible binding mechanisms were discussed.The influence of water chemical parameters on pyrene binding was studied to elucidate the effects of DOM steric conformation.DOM fraction with larger M w（14000） showed a greater KDOM（2.02×10 5） than that with smaller Mw did,and the KDOMs were 1.16×105 and 1.13×105 for the fractions with M w of 1000―14000 and 1000,respectively.The K DOM s of different M w DOM fractions were correlated positively with the atomic ratio of C/H and absorbance at 280 nm;while a negative correlation existed between K DOM and（O＋C）/N（atomic ratio）,and K DOM and O-containing groups.These correlations indicate the positive influence of aromatic structure and the negative effect of polarity on DOM binding capacity.Infrared spectroscopy revealed that specific interactions existed between pyrene and the DOM fraction with larger M W besides hydrophobic partition,i.e.,NH-π interaction in DOM moiety（1000―14000） and π-π electron donor acceptor（EDA） forces in DOM moiety（14000）.KDOM varied in a complex pattern with increasing cation concentration and pH,which could be explained by the change in DOM steric conformation.Formed aggregates favored the lipophilic partition of pyrene.However,the accessibility to some interior binding sites became low when the aggregate was too large,leading to a reduced KDOM.

Synthesis,Crystal Structure and Biological Activity of 2-(1-(3-Bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carbonyl)piperidin-4-yl)-N-isopropyl-1,3-thiazole-4-carboxamide

The title compound 2-（1-（3-bromo-1-（3-chloropyridin-2-yl）-1H-pyrazole-5-carbonyl）piperidin-4-yl）-N-isopropylthiazole-4-carboxamide（C21H22Br Cl N6O2 S,Mr = 536.04） has been synthesized,and its structure was characterized by IR spectra,1H-NMR,13C-NMR,EA,and single-crystal X-ray diffraction.The crystal of the title compound belongs to monoclinic system,space group P/c with a = 15.146（3）,b = 11.573（2）,c = 26.937（5） A,β = 103.64（3）°,V = 1839.0（6） A^3,Z = 4,Dc = 1.557 g/cm^3,μ（Mo Ka） = 0.71073 mm^-1,F（000） = 2192,R = 0.0601 and w R = 0.1392.There exist one intramolecular hydrogen bond at N–H···N and four intermolecular weak interactions at O（2）···H（1）,Cl（1）···H（12）,O（1）···Cl（1） and S（1）···O（2）.Bioassay results indicated that the title compound had good fungicidal and antiviral activities against tobacco mosaic virus.

Synthesis and Crystal Structure of 2-Ethoxy-spiro[2H-1, 4,2-benzoxazaphosphorine-3(4H), 1'-Cycloheptane] 2-Oxide

The title compound 2-ethoxy-spiro[2H-1,4,2-benzoxazaphosphorine-3（4H）,1＇-cycloheptane] 2-oxide （C15H22NO3P） was synthesized by the Mannich-type reaction of ο-amino-phenol with ethyl dichlorophosphinite and cycloheptanone, and structurally characterized by single-crystal X-ray diffraction analysis. It crystallizes in orthorhombic, space group P212121 with a = 8.9840（12）, b = 9.2978（12）, c = 37.205（5） A, V= 3107.8（7） ,A^3, Z= 8, Mr = 295.31, Dc = 1.262 g/cm^3, F（000） = 1264, μ = 0.184 mm^-1, S = 1.026, the final R = 0.0502 and wR = 0.1017 for 3849 observed reflections with Ⅰ 〉 2σ（Ⅰ） and 378 variable parameters. The structure exhibits that the six-membered phosphorus heterocycle is in the envelope conformation.

Dimethyl carbonate synthesis via transesterification catalyzed by quaternary ammonium salt functionalized chitosan

A quaternary ammonium salt covalently linked to chitosan was first used as a catalyst for dimethyl carbonate （DMC） synthesis by the transesterification of propylene carbonate （PC） with methanol. The effects of various reaction variables like reaction time, temperature and pressure on the catalytic performance were also investigated. 54% DMC yield and 71% PC conversion were obtained under the optimal reaction conditions. Notably, the catalyst was able to be reused with retention of high catalytic activity and selectivity. Consequently, the process presented here has great potential for industrial application due to its advantages such as stability, easy preparation from renewable biopolymer, and simple separation from products.

Synthesis, Crystal Structure and Biological Activity of 2-(3,4-Dichloroisothiazol-5-yl)-4-(trifluoromethyl)-4,5-dihydrothiazol-4-yl-3-methylbenzoate

The title compound diethyl 2-（3,4-dichloroisothiazol-5-yl）-4-（trifluoromethyl）-4,5- dihydrothiazol-4-yl-3-methylbenzoate （C15H9C12F3N202S2, Mr = 441.26） was prepared from methyl 3,4-dichloroisothiazole-5-carboxylate as the starting material by four steps of reaction. Its structure was characterized by IR, 1H-NMR, 13C-NMR, EA and single-crystal X-ray diffraction. The crystal of the title compound belongs to the monoclinic system, space group P2dc with a = 8.8437（18）, b = 16.128（3）, c = 12.305（3） A, β = 91.68（3）°, V= 1754.4（6） A3, Z = 4, Dc = 1.671 g/cm3,μ（MoKa） = 0,71073 mm^-1, F（000） = 888, R = 0.0384 and wR = 0.0778. Weak π-π interactions occur between the isothiazole rings and phenyl rings of adjacent molecules to form a one-dimensional chain and stabilize the crystal structure. Bioassay indicates that the title compound has good activity against the fungi and TMV tested.