A straightforward protocol using readily available aromatic amines,N,N,N',N'-tetramethyl-p-phenylenediamine or N,N,N',N'-tetramethylbenzidine,as photocatalysts was developed for theefficient hydrodehal...A straightforward protocol using readily available aromatic amines,N,N,N',N'-tetramethyl-p-phenylenediamine or N,N,N',N'-tetramethylbenzidine,as photocatalysts was developed for theefficient hydrodehalogenation of organic halides,such as 4'-bromoacetophenone,polyfluoroarenes,cholorobenzene,and 2,2',4,4'-tetrabromodiphenyl ether(a resistant and persistent organic pollu-tant).The strongly reducing singlet excited states of the amines enabled diffusion-controlled disso-ciative electron transfer to effectively cleave carbon-halogen bonds,followed by radical hydrogena-tion.Diisopropylethylamine served as the terminal electron/proton donor and regenerated theamine sensitizers.展开更多
（6-Amino-2-chloro-3-fluorophenyl）methanol is prepared through both traditional methods and palladium catalyzed iterative C–H halogenation reactions.In comparison to traditional approach,the C–H functionalization s...（6-Amino-2-chloro-3-fluorophenyl）methanol is prepared through both traditional methods and palladium catalyzed iterative C–H halogenation reactions.In comparison to traditional approach,the C–H functionalization strategy demonstrated a few advantages including milder reaction conditions higher yields,better selectivity and practicality,and high chemical diversity.展开更多
Li-S batteries have aroused intense interests as one of the most promising high-energy-density storage technology.However,the complex undesired shuttle effect induced by dissolution and diffusion of lithium polysulfid...Li-S batteries have aroused intense interests as one of the most promising high-energy-density storage technology.However,the complex undesired shuttle effect induced by dissolution and diffusion of lithium polysulfide intermediates remains the major setback of this technology.Chemical modification of carbon cathode through heteroatom-doping is widely accepted as an effective method to inhibit the shuttle effect in Li-S battery cathode.Herein,using first principle calculations,we systematically examined the interaction between halogenated graphene and lithium polysulfide species.It is found that the halogen dopants(F,Cl,Br,I)significantly modify the local electronic structure of adsorption site and further induce a polarization to trap the polysulfides.Interestingly,a concave curve is observed from F to I for lithium polysulfide adsorption rather than a linear relation.The exceptions demonstrated from iodine dopant is carefully analyzed and attributed to its unique charge state.Moreover,boron as second dopant further strengthens the interaction between halogenated graphene and polysulfide molecule.Based on halogenation strategy,lithium polysulfide/cathode interactions are tuned in a wide range,which can also be of great importance to accelerate redox reaction in Li-S battery.Overall,an effective method by halogenation is verified to regulate the adsorption of lithium polysulfide and also enhance the reaction kinetics of the Li-S battery system.展开更多
Despite the extensive application of advanced oxidation processes(AOPs)in water treatment,the efficiency of AOPs in eliminating various emerging contaminants such as halogenated antibiotics is constrained by a number ...Despite the extensive application of advanced oxidation processes(AOPs)in water treatment,the efficiency of AOPs in eliminating various emerging contaminants such as halogenated antibiotics is constrained by a number of factors.Halogen moieties exhibit strong resistance to oxidative radicals,affecting the dehalogenation and detoxification efficiencies.To address these limitations of AOPs,advanced reduction processes(ARPs)have been proposed.Herein,a novel nucleophilic reductant—namely,the carbon dioxide radical anion(CO_(2)^(·-))—is introduced for the simultaneous degradation,dehalogenation,and detoxification of florfenicol(FF),a typical halogenated antibiotic.The results demonstrate that FF is completely eliminated by CO_(2)^(·-),with approximately 100%of Cland 46%of Freleased after 120 min of treatment.Simultaneous detoxification is observed,which exhibits a linear response to the release of free inorganic halogen ions(R^(2)=0.97,p<0.01).The formation of halogen-free products is the primary reason for the superior detoxification performance of this method,in comparison with conventional hydroxyl-radical-based AOPs.Products identification and density functional theory(DFT)calculations reveal the underlying dehalogenation mechanism,in which the chlorine moiety of FF is more susceptible than other moieties to nucleophilic attack by CO_(2)^(·-).Moreover,CO_(2)^(·-)-based ARPs exhibit superior dehalogenation efficiencies(>75%)in degrading a series of halogenated antibiotics,including chloramphenicol(CAP),thiamphenicol(THA),diclofenac(DLF),triclosan(TCS),and ciprofloxacin(CIP).The system shows high tolerance to the pH of the solution and the presence of natural water constituents,and demonstrates an excellent degradation performance in actual groundwater,indicating the strong application potential of CO_(2)^(·-)-based ARPs in real life.Overall,this study elucidates the feasibility of CO_(2)^(·-)for the simultaneous degradation,dehalogenation,and detoxification of halogenated antibiotics and provides a promising method for their regulation during water or wastewater treatment.展开更多
An analytical model describing the physical relations of a UV-based process for halogenation of polymeric surfaces is presented. The process allows, depending on the parameters, a local halogenation with sharp edges a...An analytical model describing the physical relations of a UV-based process for halogenation of polymeric surfaces is presented. The process allows, depending on the parameters, a local halogenation with sharp edges at the interfaces to areas where no halogenation is desired. This is achieved via a nonreactive halogen-containing gaseous precursor and a UV source providing photons which dissociate the precursor photolytically. Thus, only where the UV photons affect the precursor, halogens are generated and the polymer is being halogenated.展开更多
An efficient and greener protocol for the synthesis of 1-halo-naphthols by the action of hydrogen peroxide and alkali metal halides in aqueous micellar media is been described in the present work. This is an environme...An efficient and greener protocol for the synthesis of 1-halo-naphthols by the action of hydrogen peroxide and alkali metal halides in aqueous micellar media is been described in the present work. This is an environmentally clean and safe procedure, which involved insitu generation of the active halogen in presence of alkali halides. Cationic surfactants such as cetyltrimethylammoniumbromide (CTAB) and cetyltrimethylammoniumchloride (CTAC) were found to facilitate efficiency of halogenation in aqueous media.展开更多
Substituted 2-halomethyl-2,3-dihydrobenzofurans were synthesized in one pot and in mild yield from substituted o-allylphenols with diacetoxyiodobenzene in the presence of 12 or Br2 in dry CH2Cl2 under reflux.
We herein uncovered an electrochemical C—H halogenation protocol that synergistically combines anodic oxidation and cathodic reduction for C—X bond formation. The reaction was demonstrated under exogenous-oxidant-fr...We herein uncovered an electrochemical C—H halogenation protocol that synergistically combines anodic oxidation and cathodic reduction for C—X bond formation. The reaction was demonstrated under exogenous-oxidant-free conditions. Moreover, this is the first example of activating CBr4, CHBr3, and CCl3Br under electrochemical conditions.展开更多
Developing novel unfused building blocks with simple synthesis and low cost is essential to advance and enrich cost-effective poly-mer donors;however,it remains a challenge due to the lack of efficient molecular strat...Developing novel unfused building blocks with simple synthesis and low cost is essential to advance and enrich cost-effective poly-mer donors;however,it remains a challenge due to the lack of efficient molecular strategies.Herein,a class of low-cost and fully unfused polymer donors with precisely regulated backbone planarity via halogenation was designed and synthesized,namely PDTBTBz-2H,PDTBTBz-2F,and PDTBTBz-2Cl.These polymer donors possess a four-step synthesis route with over 80%yield from cheap raw chemicals comparable to existing low-cost polymer donors,such as PTQ10.Benefitting from the planar backbone via in-corporating the F…S non-covalent interactions,PDTBTBz-2F exhibits more robust J-type aggregation in solution and a long-ranged molecular stacking in film relative to PDTBTBz-2H and PDTBTBz-2Cl.Moreover,the systematical study of PDTBTBz-based organic so-lar cells(OSCs)reveals the close relationship between optimized molecular self-assembly and charge separation/transport regarding backbone halogenation when paired with the non-fullerene acceptor(Y6-BO-4F).As a result,the photovoltaic devices based on semicrystalline PDTBTBz-2F achieved a promising power conversion efficiency(PCE)of 12.37%.Our work highlighted the influence of backbone halogenation on the molecular self-assembly properties and a potential unfused backbone motif for further developing cost-effective OSCs.展开更多
P-chirogenic compounds have been applied in different fields,especially in asymmetric catalysis as ligands and organocatalysts.However,broader applicability has been severely restricted by the lack of efficient synthe...P-chirogenic compounds have been applied in different fields,especially in asymmetric catalysis as ligands and organocatalysts.However,broader applicability has been severely restricted by the lack of efficient synthetic methods.Consequently,developing efficient methods to access these compounds is of high synthetic value.Herein,we report a convenient,efficient,and unprecedented pathway to construct valuable P-chirogenic compounds via chiral selenide-catalyzed enantioselective electrophilic aromatic halogenation.Using a new chiral bifunctional selenide as the catalyst,a variety of bis(2-hydroxyaryl)aryl phosphine oxides were efficiently converted to the corresponding chlorinated and brominated P-chirogenic compounds with good to excellent enantioselectivities.By slightly adjusting the catalyst and solvent,this method is also able to prepare chiral alkyl diaryl phosphine oxides and diaryl phosphinates.Furthermore,control experiments revealed the decomposition pathways of catalysts and the possible reasons why chiral selenide catalyst was more effective than chiral sulfide catalyst.The effect of hydrogen bonding was studied,and the reason why the chlorination took place on the various aromatic rings was elucidated when the substrates were switched from triaryl phosphine oxides to alkyl diaryl phosphine oxides and diaryl phosphinates.展开更多
A TEMPO catalyzed cross-dihalogenation reaction was established via redox-regulation of the otherwise complex system of dual electrophilic X+reagents.Formally,the ICl,BrCl,I_(2) and Br_(2) were generated in-situ,which...A TEMPO catalyzed cross-dihalogenation reaction was established via redox-regulation of the otherwise complex system of dual electrophilic X+reagents.Formally,the ICl,BrCl,I_(2) and Br_(2) were generated in-situ,which enabled high regio-or stereoselective access to a myriad of iodochlorination,bromochlorination and homo-dihalogenation products with a wide spectrum of functionalities.With its mild conditions and operational simplicity,this method could enable wide applications in organic synthesis,which was exemplified by divergent synthesis of two pharmaceuticals.Detailed mechanistic investigations via radical clock reaction,pinacol ring expansion and Hammett experiments were conducted,which confirmed the intermediacy of halonium ion.In addition,a dynamic catalytic model based on the versatile catalytic role of TEMPO was proposed to explain the selective outcomes.展开更多
Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from...Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from the cathode side.These challenges lead to poor cycle stability and severe self-discharge.From the fabrication and cost point of view,it is technologically more viable to deploy electrolyte engineering than electrode protection strategies.More importantly,a synchronous method for modulation of both cathode and anode is pivotal,which has been often neglected in prior studies.In this work,cationic poly(allylamine hydrochloride)(Pah^(+))is adopted as a low-cost dual-function electrolyte additive for ZIBs.We elaborate the synchronous effect by Pah^(+)in stabilizing Zn anode and immobilizing polyiodide anions.The fabricated Zn-iodine coin cell with Pah^(+)(ZnI_(2) loading:25 mg cm^(−2))stably cycles 1000 times at 1 C,and a single-layered 3.4 cm^(2) pouch cell(N/P ratio~1.5)with the same mass loading cycles over 300 times with insignificant capacity decay.展开更多
Synthesis and characterization of (Z)-1-[2-(triphenylstannyl)vinylj-l-cyclododecanol,c-(CH2)11C(OH)CH=CHSnPh3,are reported,together with its halogenation by I2,Br2 and IC1 to yield derivatives of the types c-(CH2)11C(...Synthesis and characterization of (Z)-1-[2-(triphenylstannyl)vinylj-l-cyclododecanol,c-(CH2)11C(OH)CH=CHSnPh3,are reported,together with its halogenation by I2,Br2 and IC1 to yield derivatives of the types c-(CH2)11C(OH)CH=CHSnPh3_nXn (n=1,2; X=I,Br,Cl,respectively).The molecular structures of two compounds have been determined by X-ray diffraction analysis.The tin atom exhibits a distorted tetrahedral geometry in the crystal of (Z)-1-[2-(triphenylstannyl)vinyl]-1-cyclododecanol,but a trigonal bipyramidal geometry in the monoiodo-derivative (Z)-1-[2-(diphenyliodo-stannyl)vinyl]-l-cyclododecanol and other derivatives,in which significant intramolecular coordinative interaction HO→Sn is observed.And the formation of a five-membered tin containing ring is significant for their antitumour activities.展开更多
Existing organic halide synthesis routes typically employ elemental halogens(X_(2),X=Cl or Br),leading to low atom economy and significant environmental pollution.In this work,we developed an atom efficient electrosyn...Existing organic halide synthesis routes typically employ elemental halogens(X_(2),X=Cl or Br),leading to low atom economy and significant environmental pollution.In this work,we developed an atom efficient electrosynthesis and separation strategy for halogenation reagents—N-chlorosuccinimide(NCS)and N-bromosuccinimide(NBS)—at high current densities.Faradic efficiency(FE)of 91.0%and 81.3%was achieved for NCS and NBS generation on RuO_(x)/TiO_(2)/Ti in a batch cell,respectively.Electrosynthesis of NCS likely involves both heterogeneous catalytic and homogeneous tandem pathways,while NBS is likely formed in a Langmuir-Hinshelwood mechanism with a proton-coupled electron transfer as the rate-determining step.A coupled continuous electrocatalytic synthesis and in situ separation setup was developed for the efficient production of NCS and NBS,which yielded 0.77 g of NCS in 12000 s and 0.81 g of NBS in 15000 s,both with relative purity exceeding 95%.The halogenation of acetone using NCS and NBS enabled gram-scale production of the key intermediate in organic synthesis,1-halogenacetone,with over 95%recovery of succinimide.展开更多
Aqueous zinc-halogen batteries are promising candidates for large-scale energy storage due to their abundant resources,intrinsic safety,and high theoretical capacity.Nevertheless,the uncontrollable zinc dendrite growt...Aqueous zinc-halogen batteries are promising candidates for large-scale energy storage due to their abundant resources,intrinsic safety,and high theoretical capacity.Nevertheless,the uncontrollable zinc dendrite growth and spontaneous shuttle effect of active species have prohibited their practical implementation.Herein,a double-layered protective film based on zinc-ethylenediamine tetramethylene phosphonic acid(ZEA)artificial film and ZnF2-rich solid electrolyte interphase(SEI)layer has been successfully fabricated on the zinc metal anode via electrode/electrolyte synergistic optimization.The ZEA-based artificial film shows strong affinity for the ZnF2-rich SEI layer,therefore effectively suppressing the SEI breakage and facilitating the construction of double-layered protective film on the zinc metal anode.Such double-layered architecture not only modulates Zn2+flux and suppresses the zinc dendrite growth,but also blocks the direct contact between the metal anode and electrolyte,thus mitigating the corrosion from the active species.When employing optimized metal anodes and electrolytes,the as-developed zinc-(dual)halogen batteries present high areal capacity and satisfactory cycling stability.This work provides a new avenue for developing aqueous zinc-(dual)halogen batteries.展开更多
The highly selective catalytic hydrogenation of halogenated nitroaromatics was achieved by employing Pd‑based catalysts that were co‑modified with organic and inorganic ligands.It was demonstrated that the catalysts c...The highly selective catalytic hydrogenation of halogenated nitroaromatics was achieved by employing Pd‑based catalysts that were co‑modified with organic and inorganic ligands.It was demonstrated that the catalysts contained Pd species in mixed valence states,with high valence Pd at the metal‑support interface and zero valence Pd at the metal surface.While the strong coordination of triphenylphosphine(PPh3)to Pd0 on the Pd surface prevents the adsorption of halogenated nitroaromatics and thus dehalogenation,the coordination of sodium metavanadate(NaVO3)to high‑valence Pd sites at the interface helps to activate H2 in a heterolytic pathway for the selective hydrogenation of nitro‑groups.The excellent catalytic performance of the interfacial active sites enables the selective hydrogenation of a wide range of halogenated nitroaromatics.展开更多
The piezocatalytic characteristic of bismuth oxyhalides(BiOX,X=Cl,Br,and I) has been increasingly capturing interest for its potential in hydrogen evolution reaction(HER) through water splitting process.The performanc...The piezocatalytic characteristic of bismuth oxyhalides(BiOX,X=Cl,Br,and I) has been increasingly capturing interest for its potential in hydrogen evolution reaction(HER) through water splitting process.The performance regarding these piezocatalysts is closely related to the halogen element present in BiOX;yet,the specific influence mechanisms remain unclear.In this study,we prepared BiOX catalysts via a hydrothermal process and explored their piezocatalytic HER activities.Owing to the layered bismuth s tructure,the resulting sheet-like piezocatalysts can efficiently capture the mechanic stimulus and allow the robust piezoelectric field,contributing to the piezocatalytic operation.It demonstrates that the BiOBr achieves a remarkable piezocatalytic HER efficiency of 813 μmol g^(-1)h^(-1),outperforming BiOCl and BiOI.The density functional theory(DFT)calculation results reveal that the BiOBr with moderate halogen atom size and lattice layer spacing possesses the strongest piezoelectricity,which enhances the separation and transfer of electron-hole pairs.Meanwhile,the exposed Br atom layer facilitates a large Bader charge and a low surface Gibbs free energy(ΔG_(H)),enhancing charge transfer for hydrogen reduction at the solid-liquid surface,thereby increasing the HER efficiency.This research sheds light on the halogen-dependent piezocatalytic activity of BiOX catalysts,offering valuable insights for the development of high-performance piezocatalysts.展开更多
Heteroatom doping has emerged as a powerful strategy to optimize the catalytic and adsorption abilities of electrocatalysts by regulating the electronic structure,thereby enabling the development of efficient electroc...Heteroatom doping has emerged as a powerful strategy to optimize the catalytic and adsorption abilities of electrocatalysts by regulating the electronic structure,thereby enabling the development of efficient electrocatalysts for lithium-sulfur(Li-S)batteries.However,the correlation between the properties of doped atoms and adsorptio n-catalytic ability,as well as the interconnection between adsorption strength and catalytic activity,remains underexplored.Herein,we employed halogen atoms(F,Cl,and Br)with different electronegativities to dope nickel phosphide(Ni_(2)P),aiming to modulate the adsorption properties toward lithium polysulfides(LiPSs).We systematically explored the relationship between the electronegativity of the doping atoms and the adsorption strength,followed by exploring the connection between adsorption and catalytic capabilities.Combined experimental and theoretical analyses reveal that doping halogen atoms effectively strengthens d-p orbital hybridization between Ni atoms and S atoms,thereby enhancing LiPSs anchoring and conversion.Specifically,the chemical adsorption capability is enhanced as the electronegativity of the doped atoms increases.Moreover,the catalytic activity presents a volcano-like trend with the enhancement of adsorption performance,wherein the activity initially increases and subsequently diminishes.Therefore,Cl-doped Ni_(2)P with moderate chemisorption ability exhibits optimal redox kinetics in bidirectional sulfur conversion.Consequently,the Li-S batteries with Cl-Ni_(2)P-separators deliver a high-rate capacity of 790 mAh g^(-1)at 5 C and achieve a remarkable areal capacity of 7.36 mAh cm^(-2)under practical conditions(sulfur loading:7.10 mg cm^(-2);electrolyte/sulfur(E/S)ratio:5μL mg^(-1)).This work uncovers the significance of achieving a balance between adsorption and catalytic capabilities,offering insights into designing efficient electrocatalysts for lithium-sulfur batteries.展开更多
文摘A straightforward protocol using readily available aromatic amines,N,N,N',N'-tetramethyl-p-phenylenediamine or N,N,N',N'-tetramethylbenzidine,as photocatalysts was developed for theefficient hydrodehalogenation of organic halides,such as 4'-bromoacetophenone,polyfluoroarenes,cholorobenzene,and 2,2',4,4'-tetrabromodiphenyl ether(a resistant and persistent organic pollu-tant).The strongly reducing singlet excited states of the amines enabled diffusion-controlled disso-ciative electron transfer to effectively cleave carbon-halogen bonds,followed by radical hydrogena-tion.Diisopropylethylamine served as the terminal electron/proton donor and regenerated theamine sensitizers.
基金supported by ‘973’ Project (No. 2011CB965300)NSFC (Nos. 21142008, 21302106)+1 种基金Tsinghua University 985 Phase II Fundsthe Tsinghua University Initiative Scientific Research Program
文摘（6-Amino-2-chloro-3-fluorophenyl）methanol is prepared through both traditional methods and palladium catalyzed iterative C–H halogenation reactions.In comparison to traditional approach,the C–H functionalization strategy demonstrated a few advantages including milder reaction conditions higher yields,better selectivity and practicality,and high chemical diversity.
基金supported by the NSFC(21573255)the Natural Science Foundation of Liaoning Province(20180510014)+1 种基金supported Joint Research Fund Liaoning Shenyang National Laboratory for Materials Science and the State Key Laboratory of Catalytic Materials and Reaction Engineering(RIPP,SINOPEC)supported by the Special Program for Applied Research on Super Computation of the NSFC Guangdong Joint Fund(the second phase)under Grant no.U1501501。
文摘Li-S batteries have aroused intense interests as one of the most promising high-energy-density storage technology.However,the complex undesired shuttle effect induced by dissolution and diffusion of lithium polysulfide intermediates remains the major setback of this technology.Chemical modification of carbon cathode through heteroatom-doping is widely accepted as an effective method to inhibit the shuttle effect in Li-S battery cathode.Herein,using first principle calculations,we systematically examined the interaction between halogenated graphene and lithium polysulfide species.It is found that the halogen dopants(F,Cl,Br,I)significantly modify the local electronic structure of adsorption site and further induce a polarization to trap the polysulfides.Interestingly,a concave curve is observed from F to I for lithium polysulfide adsorption rather than a linear relation.The exceptions demonstrated from iodine dopant is carefully analyzed and attributed to its unique charge state.Moreover,boron as second dopant further strengthens the interaction between halogenated graphene and polysulfide molecule.Based on halogenation strategy,lithium polysulfide/cathode interactions are tuned in a wide range,which can also be of great importance to accelerate redox reaction in Li-S battery.Overall,an effective method by halogenation is verified to regulate the adsorption of lithium polysulfide and also enhance the reaction kinetics of the Li-S battery system.
基金financially supported by the National Natural Science Foundation of China(22176059,21777042,and 22076045)the authors would also like to acknowledge support from the Science and Technology Commission of Shanghai Municipality’s Yangfan Special Project(23YF1408400)the Fundamental Research Funds for the Central Universities.
文摘Despite the extensive application of advanced oxidation processes(AOPs)in water treatment,the efficiency of AOPs in eliminating various emerging contaminants such as halogenated antibiotics is constrained by a number of factors.Halogen moieties exhibit strong resistance to oxidative radicals,affecting the dehalogenation and detoxification efficiencies.To address these limitations of AOPs,advanced reduction processes(ARPs)have been proposed.Herein,a novel nucleophilic reductant—namely,the carbon dioxide radical anion(CO_(2)^(·-))—is introduced for the simultaneous degradation,dehalogenation,and detoxification of florfenicol(FF),a typical halogenated antibiotic.The results demonstrate that FF is completely eliminated by CO_(2)^(·-),with approximately 100%of Cland 46%of Freleased after 120 min of treatment.Simultaneous detoxification is observed,which exhibits a linear response to the release of free inorganic halogen ions(R^(2)=0.97,p<0.01).The formation of halogen-free products is the primary reason for the superior detoxification performance of this method,in comparison with conventional hydroxyl-radical-based AOPs.Products identification and density functional theory(DFT)calculations reveal the underlying dehalogenation mechanism,in which the chlorine moiety of FF is more susceptible than other moieties to nucleophilic attack by CO_(2)^(·-).Moreover,CO_(2)^(·-)-based ARPs exhibit superior dehalogenation efficiencies(>75%)in degrading a series of halogenated antibiotics,including chloramphenicol(CAP),thiamphenicol(THA),diclofenac(DLF),triclosan(TCS),and ciprofloxacin(CIP).The system shows high tolerance to the pH of the solution and the presence of natural water constituents,and demonstrates an excellent degradation performance in actual groundwater,indicating the strong application potential of CO_(2)^(·-)-based ARPs in real life.Overall,this study elucidates the feasibility of CO_(2)^(·-)for the simultaneous degradation,dehalogenation,and detoxification of halogenated antibiotics and provides a promising method for their regulation during water or wastewater treatment.
文摘An analytical model describing the physical relations of a UV-based process for halogenation of polymeric surfaces is presented. The process allows, depending on the parameters, a local halogenation with sharp edges at the interfaces to areas where no halogenation is desired. This is achieved via a nonreactive halogen-containing gaseous precursor and a UV source providing photons which dissociate the precursor photolytically. Thus, only where the UV photons affect the precursor, halogens are generated and the polymer is being halogenated.
文摘An efficient and greener protocol for the synthesis of 1-halo-naphthols by the action of hydrogen peroxide and alkali metal halides in aqueous micellar media is been described in the present work. This is an environmentally clean and safe procedure, which involved insitu generation of the active halogen in presence of alkali halides. Cationic surfactants such as cetyltrimethylammoniumbromide (CTAB) and cetyltrimethylammoniumchloride (CTAC) were found to facilitate efficiency of halogenation in aqueous media.
基金We thank the National Science Foundation of China for financial support(No.29472036).
文摘Substituted 2-halomethyl-2,3-dihydrobenzofurans were synthesized in one pot and in mild yield from substituted o-allylphenols with diacetoxyiodobenzene in the presence of 12 or Br2 in dry CH2Cl2 under reflux.
基金the National Natural Science Foundation of China (No.21520102003)Introducing Talents of Discipline to Universities of China (111 Program).
文摘We herein uncovered an electrochemical C—H halogenation protocol that synergistically combines anodic oxidation and cathodic reduction for C—X bond formation. The reaction was demonstrated under exogenous-oxidant-free conditions. Moreover, this is the first example of activating CBr4, CHBr3, and CCl3Br under electrochemical conditions.
基金supported by the National Natural Science Foundation of China (52203241,21905225,22005121)the Science and Technology Program of Shaanxi Province (2022JM-229,2023-JC-QN-0448)+1 种基金Jiangsu Key Laboratory for Carbon-Based Functional Materials&Devices,Soochow University (KJS2208)H.Y.W.acknowledges the financial support from the National Research Foundation of Korea (2019R1A6A1A11044070,2020M3H4A3081814).
文摘Developing novel unfused building blocks with simple synthesis and low cost is essential to advance and enrich cost-effective poly-mer donors;however,it remains a challenge due to the lack of efficient molecular strategies.Herein,a class of low-cost and fully unfused polymer donors with precisely regulated backbone planarity via halogenation was designed and synthesized,namely PDTBTBz-2H,PDTBTBz-2F,and PDTBTBz-2Cl.These polymer donors possess a four-step synthesis route with over 80%yield from cheap raw chemicals comparable to existing low-cost polymer donors,such as PTQ10.Benefitting from the planar backbone via in-corporating the F…S non-covalent interactions,PDTBTBz-2F exhibits more robust J-type aggregation in solution and a long-ranged molecular stacking in film relative to PDTBTBz-2H and PDTBTBz-2Cl.Moreover,the systematical study of PDTBTBz-based organic so-lar cells(OSCs)reveals the close relationship between optimized molecular self-assembly and charge separation/transport regarding backbone halogenation when paired with the non-fullerene acceptor(Y6-BO-4F).As a result,the photovoltaic devices based on semicrystalline PDTBTBz-2F achieved a promising power conversion efficiency(PCE)of 12.37%.Our work highlighted the influence of backbone halogenation on the molecular self-assembly properties and a potential unfused backbone motif for further developing cost-effective OSCs.
基金the National Natural Science Foundation of China(grant nos.91856109 and 21772239)the Fundamental Research Funds for the Central Universities(grant no.20lgzd21)the Leading Scientific,Technical and Innovation Talents of Guangdong Special Support Program(grant no.2019TX05Y638)for financial support.
文摘P-chirogenic compounds have been applied in different fields,especially in asymmetric catalysis as ligands and organocatalysts.However,broader applicability has been severely restricted by the lack of efficient synthetic methods.Consequently,developing efficient methods to access these compounds is of high synthetic value.Herein,we report a convenient,efficient,and unprecedented pathway to construct valuable P-chirogenic compounds via chiral selenide-catalyzed enantioselective electrophilic aromatic halogenation.Using a new chiral bifunctional selenide as the catalyst,a variety of bis(2-hydroxyaryl)aryl phosphine oxides were efficiently converted to the corresponding chlorinated and brominated P-chirogenic compounds with good to excellent enantioselectivities.By slightly adjusting the catalyst and solvent,this method is also able to prepare chiral alkyl diaryl phosphine oxides and diaryl phosphinates.Furthermore,control experiments revealed the decomposition pathways of catalysts and the possible reasons why chiral selenide catalyst was more effective than chiral sulfide catalyst.The effect of hydrogen bonding was studied,and the reason why the chlorination took place on the various aromatic rings was elucidated when the substrates were switched from triaryl phosphine oxides to alkyl diaryl phosphine oxides and diaryl phosphinates.
基金financial support from the NSFC(Nos.21871096,22071062,22001077)the Ministry of Science and Technology of the People’s Republic of China(No.2016YFA0602900)+1 种基金the Guangdong Science and Technology Department(Nos.2018B030308007,2021A1515012331)the China Postdoctoral Science Foundation(Nos.2018M643062,2019T120723).
文摘A TEMPO catalyzed cross-dihalogenation reaction was established via redox-regulation of the otherwise complex system of dual electrophilic X+reagents.Formally,the ICl,BrCl,I_(2) and Br_(2) were generated in-situ,which enabled high regio-or stereoselective access to a myriad of iodochlorination,bromochlorination and homo-dihalogenation products with a wide spectrum of functionalities.With its mild conditions and operational simplicity,this method could enable wide applications in organic synthesis,which was exemplified by divergent synthesis of two pharmaceuticals.Detailed mechanistic investigations via radical clock reaction,pinacol ring expansion and Hammett experiments were conducted,which confirmed the intermediacy of halonium ion.In addition,a dynamic catalytic model based on the versatile catalytic role of TEMPO was proposed to explain the selective outcomes.
基金supported by the financial support from the National Research Foundation,Singapore,under its Singapore-China Joint Flagship Project(Clean Energy).
文摘Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from the cathode side.These challenges lead to poor cycle stability and severe self-discharge.From the fabrication and cost point of view,it is technologically more viable to deploy electrolyte engineering than electrode protection strategies.More importantly,a synchronous method for modulation of both cathode and anode is pivotal,which has been often neglected in prior studies.In this work,cationic poly(allylamine hydrochloride)(Pah^(+))is adopted as a low-cost dual-function electrolyte additive for ZIBs.We elaborate the synchronous effect by Pah^(+)in stabilizing Zn anode and immobilizing polyiodide anions.The fabricated Zn-iodine coin cell with Pah^(+)(ZnI_(2) loading:25 mg cm^(−2))stably cycles 1000 times at 1 C,and a single-layered 3.4 cm^(2) pouch cell(N/P ratio~1.5)with the same mass loading cycles over 300 times with insignificant capacity decay.
基金Project (No. 29170084) supported by the National Natural Science Foundation of China
文摘Synthesis and characterization of (Z)-1-[2-(triphenylstannyl)vinylj-l-cyclododecanol,c-(CH2)11C(OH)CH=CHSnPh3,are reported,together with its halogenation by I2,Br2 and IC1 to yield derivatives of the types c-(CH2)11C(OH)CH=CHSnPh3_nXn (n=1,2; X=I,Br,Cl,respectively).The molecular structures of two compounds have been determined by X-ray diffraction analysis.The tin atom exhibits a distorted tetrahedral geometry in the crystal of (Z)-1-[2-(triphenylstannyl)vinyl]-1-cyclododecanol,but a trigonal bipyramidal geometry in the monoiodo-derivative (Z)-1-[2-(diphenyliodo-stannyl)vinyl]-l-cyclododecanol and other derivatives,in which significant intramolecular coordinative interaction HO→Sn is observed.And the formation of a five-membered tin containing ring is significant for their antitumour activities.
文摘Existing organic halide synthesis routes typically employ elemental halogens(X_(2),X=Cl or Br),leading to low atom economy and significant environmental pollution.In this work,we developed an atom efficient electrosynthesis and separation strategy for halogenation reagents—N-chlorosuccinimide(NCS)and N-bromosuccinimide(NBS)—at high current densities.Faradic efficiency(FE)of 91.0%and 81.3%was achieved for NCS and NBS generation on RuO_(x)/TiO_(2)/Ti in a batch cell,respectively.Electrosynthesis of NCS likely involves both heterogeneous catalytic and homogeneous tandem pathways,while NBS is likely formed in a Langmuir-Hinshelwood mechanism with a proton-coupled electron transfer as the rate-determining step.A coupled continuous electrocatalytic synthesis and in situ separation setup was developed for the efficient production of NCS and NBS,which yielded 0.77 g of NCS in 12000 s and 0.81 g of NBS in 15000 s,both with relative purity exceeding 95%.The halogenation of acetone using NCS and NBS enabled gram-scale production of the key intermediate in organic synthesis,1-halogenacetone,with over 95%recovery of succinimide.
基金support from the National Natural Science Foundation of China(22209089,22178187)Natural Science Foundation of Shandong Province(ZR2022QB048,ZR2021MB006)+2 种基金Excellent Youth Science Foundation of Shandong Province(Overseas)(2023HWYQ-089)the Taishan Scholars Program of Shandong Province(tsqn201909091)Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal University.
文摘Aqueous zinc-halogen batteries are promising candidates for large-scale energy storage due to their abundant resources,intrinsic safety,and high theoretical capacity.Nevertheless,the uncontrollable zinc dendrite growth and spontaneous shuttle effect of active species have prohibited their practical implementation.Herein,a double-layered protective film based on zinc-ethylenediamine tetramethylene phosphonic acid(ZEA)artificial film and ZnF2-rich solid electrolyte interphase(SEI)layer has been successfully fabricated on the zinc metal anode via electrode/electrolyte synergistic optimization.The ZEA-based artificial film shows strong affinity for the ZnF2-rich SEI layer,therefore effectively suppressing the SEI breakage and facilitating the construction of double-layered protective film on the zinc metal anode.Such double-layered architecture not only modulates Zn2+flux and suppresses the zinc dendrite growth,but also blocks the direct contact between the metal anode and electrolyte,thus mitigating the corrosion from the active species.When employing optimized metal anodes and electrolytes,the as-developed zinc-(dual)halogen batteries present high areal capacity and satisfactory cycling stability.This work provides a new avenue for developing aqueous zinc-(dual)halogen batteries.
文摘The highly selective catalytic hydrogenation of halogenated nitroaromatics was achieved by employing Pd‑based catalysts that were co‑modified with organic and inorganic ligands.It was demonstrated that the catalysts contained Pd species in mixed valence states,with high valence Pd at the metal‑support interface and zero valence Pd at the metal surface.While the strong coordination of triphenylphosphine(PPh3)to Pd0 on the Pd surface prevents the adsorption of halogenated nitroaromatics and thus dehalogenation,the coordination of sodium metavanadate(NaVO3)to high‑valence Pd sites at the interface helps to activate H2 in a heterolytic pathway for the selective hydrogenation of nitro‑groups.The excellent catalytic performance of the interfacial active sites enables the selective hydrogenation of a wide range of halogenated nitroaromatics.
基金financially supported by the Natural Science Foundation of Shandong Province(No.ZR2023MB151)the Natural Science Foundation of Shandong Province for Excellent Young Scholars(No.ZR2022YQ13)+1 种基金the Science and Technology Special Project of Qingdao(No.24-1-8-xdny-18nsh)the Taishan Scholar Project of Shandong Province(No.tsqn202211159)
文摘The piezocatalytic characteristic of bismuth oxyhalides(BiOX,X=Cl,Br,and I) has been increasingly capturing interest for its potential in hydrogen evolution reaction(HER) through water splitting process.The performance regarding these piezocatalysts is closely related to the halogen element present in BiOX;yet,the specific influence mechanisms remain unclear.In this study,we prepared BiOX catalysts via a hydrothermal process and explored their piezocatalytic HER activities.Owing to the layered bismuth s tructure,the resulting sheet-like piezocatalysts can efficiently capture the mechanic stimulus and allow the robust piezoelectric field,contributing to the piezocatalytic operation.It demonstrates that the BiOBr achieves a remarkable piezocatalytic HER efficiency of 813 μmol g^(-1)h^(-1),outperforming BiOCl and BiOI.The density functional theory(DFT)calculation results reveal that the BiOBr with moderate halogen atom size and lattice layer spacing possesses the strongest piezoelectricity,which enhances the separation and transfer of electron-hole pairs.Meanwhile,the exposed Br atom layer facilitates a large Bader charge and a low surface Gibbs free energy(ΔG_(H)),enhancing charge transfer for hydrogen reduction at the solid-liquid surface,thereby increasing the HER efficiency.This research sheds light on the halogen-dependent piezocatalytic activity of BiOX catalysts,offering valuable insights for the development of high-performance piezocatalysts.
基金supported by the Beijing Institute of Technology Research Fund Program for Young Scholars and 21C Innovation Laboratory Contemporary Amperex Technology Co.,Limited,Ninde,352100,China(21C-OP-202314)。
文摘Heteroatom doping has emerged as a powerful strategy to optimize the catalytic and adsorption abilities of electrocatalysts by regulating the electronic structure,thereby enabling the development of efficient electrocatalysts for lithium-sulfur(Li-S)batteries.However,the correlation between the properties of doped atoms and adsorptio n-catalytic ability,as well as the interconnection between adsorption strength and catalytic activity,remains underexplored.Herein,we employed halogen atoms(F,Cl,and Br)with different electronegativities to dope nickel phosphide(Ni_(2)P),aiming to modulate the adsorption properties toward lithium polysulfides(LiPSs).We systematically explored the relationship between the electronegativity of the doping atoms and the adsorption strength,followed by exploring the connection between adsorption and catalytic capabilities.Combined experimental and theoretical analyses reveal that doping halogen atoms effectively strengthens d-p orbital hybridization between Ni atoms and S atoms,thereby enhancing LiPSs anchoring and conversion.Specifically,the chemical adsorption capability is enhanced as the electronegativity of the doped atoms increases.Moreover,the catalytic activity presents a volcano-like trend with the enhancement of adsorption performance,wherein the activity initially increases and subsequently diminishes.Therefore,Cl-doped Ni_(2)P with moderate chemisorption ability exhibits optimal redox kinetics in bidirectional sulfur conversion.Consequently,the Li-S batteries with Cl-Ni_(2)P-separators deliver a high-rate capacity of 790 mAh g^(-1)at 5 C and achieve a remarkable areal capacity of 7.36 mAh cm^(-2)under practical conditions(sulfur loading:7.10 mg cm^(-2);electrolyte/sulfur(E/S)ratio:5μL mg^(-1)).This work uncovers the significance of achieving a balance between adsorption and catalytic capabilities,offering insights into designing efficient electrocatalysts for lithium-sulfur batteries.
