Due to the advantages of high surface areas, large pore volumes and pore sizes, abundant nitrogen content that favored the metal-support interactions, N-doped ordered mesoporous carbons are regarded as a kind ...Due to the advantages of high surface areas, large pore volumes and pore sizes, abundant nitrogen content that favored the metal-support interactions, N-doped ordered mesoporous carbons are regarded as a kind of fascinating and potential support for the synthesis of effective supported cat-alysts. Here, a N-doped ordered mesoporous carbon with a high N content （9.58 wt%）, high surface area （417 m^2/g）, and three-dimensional cubic structure was synthesized successfully and used as an effective support for immobilizing Pt nanoparticles （NPs）. The positive effects of nitrogen on the metal particle size enabled ultrasmall Pt NPs （about 1.0 ± 0.5 nm） to be obtained. Moreover, most of the Pt NPs are homogeneously dispersed in the mesoporous channels. However, using the ordered mesoporous carbon without nitrogen as support, the particles were larger （4.4 ± 1.7 nm） and many Pt NPs were distributed on the external surface, demonstrating the important role of the nitrogen species. The obtained N-doped ordered mesoporous material supported catalyst showed excellent catalytic activity （conversion 100%） and selectivity （〉99%） in the hydrogenation of halogenated nitrobenzenes under mild conditions. These values are much higher than those achieved using a commercial Pt/C catalyst （conversion 89% and selectivity 90%）. This outstanding catalytic perfor-mance can be attributed to the synergetic effects of the mesoporous structure, N-functionalized support, and stabilized ultrasmall Pt NPs. Moreover, such supported catalyst also showed excellent catalytic performance in the hydrogenation of other halogenated nitrobenzenes and nitroarenes. In addition, the stability of the multifunctional catalyst was excellent and it could be reused more than 10 times without significant losses of activity and selectivity. Our results conclusively show that a N-doped carbon support enable the formation of ultrafine metal NPs and improve the reaction ac-tivity and selectivity.展开更多
The ubiquitous distribution of halogenated aromatic compounds（XAr） coupled with their carcinogenicity has raised public concerns on their potential risks to both human health and the ecosystem. Recently, advanced ox...The ubiquitous distribution of halogenated aromatic compounds（XAr） coupled with their carcinogenicity has raised public concerns on their potential risks to both human health and the ecosystem. Recently, advanced oxidation processes（AOPs） have been considered as an＂environmentally-friendly＂ technology for the remediation and destruction of such recalcitrant and highly toxic XAr. During our study on the mechanism of metal-independent production of hydroxyl radicals（UOH） by halogenated quinones and H_2O_2, we found, unexpectedly, that an unprecedented UOH-dependent two-step intrinsic chemiluminescene（CL） can be produced by H_2O_2 and tetrachloro-p-benzoquinone, the major carcinogenic metabolite of the widely used wood preservative pentachlorophenol. Further investigations showed that, in all UOH-generating systems, CL can also be produced not only by pentachlorophenol and all other halogenated phenols, but also by all XAr tested. A systematic structure–activity relationship study for all 19 chlorophenolic congeners showed that the CL increased with an increasing number of Cl-substitution in general. More importantly, a relatively good correlation was observed between the formation of quinoid/semiquinone radical intermediates and CL generation. Based on these results, we propose that UOH-dependent formation of quinoid intermediates and electronically excited carbonyl species is responsible for this unusual CL production; and a rapid, sensitive,simple, and effective CL method was developed not only to detect and quantify trace amount of XAr, but also to provide useful information for predicting the toxicity or monitoring real-time degradation kinetics of XAr. These findings may have broad chemical, environmental and biological implications for future studies on halogenated aromatic persistent organic pollutants.展开更多
In this paper we take photobacterium phosphoreum （T3） as the experimental bacteria, and determine the half-inhibitory concentration （-1gEC50） against the photobacterium phosphoreum of 16 halogenated benzenes. Usin...In this paper we take photobacterium phosphoreum （T3） as the experimental bacteria, and determine the half-inhibitory concentration （-1gEC50） against the photobacterium phosphoreum of 16 halogenated benzenes. Using B3LYP method of DFT in the Gaussian 03 program, we obtain the structural and thermodynamic descriptors of 16 halogenated benzenes by fully-optimized calculation at the 6-311G＊＊ level. Taking the structural and thermodynamic descriptors as theoretical descriptors, the 2D QSAR model （R2 = 0.983） was established, which can be utilized to predict -lgEC50 of halogenated benzene according to the corrected linear solvation energy theory based on the experimental data of-lgECs0. In addition, the relationship between the toxicity and 3D spatial structure of the compound is studied by comparing the molecular similarity index analysis （CoMSIA） of 3D-QSAR method. By cross validation, the correlation coefficient q2 of CoMSIA model is 0.687, and the conventional correlation coefficient R2 = 0.958. The model is stable and reliable with great predictive ability. The 3D-QSAR model shows that the toxicity of halogenated benzene compound is mainly affected by the characteristics of hydrophobie field of the substituted halogens.展开更多
Environmental water samples can be extremely complex,with potentially thousands of molecules that can derive from natural organic matter（NOM）and thousands that derive from anthropogenic contaminants.As complex as th...Environmental water samples can be extremely complex,with potentially thousands of molecules that can derive from natural organic matter（NOM）and thousands that derive from anthropogenic contaminants.As complex as these samples are,drinking water can be even more complex.Due to disinfectants that are used to treat drinking water（e.g.,chlorine,chloramines,展开更多
Halogenated methyl-phenyl ethers （anisoles） are ubiquitous organic compounds in the environment. In the present study, geometrical optimization and electrostatic potential calculations have been performed for 42 hal...Halogenated methyl-phenyl ethers （anisoles） are ubiquitous organic compounds in the environment. In the present study, geometrical optimization and electrostatic potential calculations have been performed for 42 halogenated anisoles at the HF/6-31 G^＊ level. A number of statistically based parameters have been obtained. By multiple regression method, linear relationships between the gas-chromatographic relative retention time （RRT） and structural descriptors have been established for the training set of 32 halogenated anisoles. The result showed that the parameters derived from electrostatic potentials （ESPs） together with the molecular volume （Vmc） could be well used to express the quantitative structure-RRT relationships of halogenated anisoles. The best two-variable regression model gives a correlation coefficient of 0.980 and a standard deviation of 0.07, and the leave-one-out cross-validated correlation coefficient is 0.975. The goodness of the model has been further validated through exploring the predictive power for the testing set of 10 halogenated anisoles.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(R2=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展开更多
Ensuring the health and safety of drinking water is crucial for both nations and their citizens.Since the 20th century,the disinfection of drinking water,effectively controlling pathogens in water sources,has become o...Ensuring the health and safety of drinking water is crucial for both nations and their citizens.Since the 20th century,the disinfection of drinking water,effectively controlling pathogens in water sources,has become one of the significant advances in public health.However,the disinfectants used in the process,such as chlorine and chlorine dioxide,react with natural organic matter in the water to produce disinfection by-products(DBPs).Most of these DBPs contain chlorine,and if the source water contains bromine or iodine,brominated or iodinated DBPs,collectively referred to as Halogenated disinfection byproducts(X-DBPs),are formed.Numerous studies have found that X-DBPs pose potential risks to human health and the environment,leading to widespread concern.Mass spectrometry has become an important means of discovering new types of X-DBPs.This paper focuses on the study of methods for analyzing X-DBPs in drinking water using mass spectrometry.展开更多
This study shows that minor amount of water plays a very important role in solvent-free hydrogenation of halogenated nitrobenzenes. For dried sponge Pd, the reaction cannot occur in the absence of water. For Pd/C cata...This study shows that minor amount of water plays a very important role in solvent-free hydrogenation of halogenated nitrobenzenes. For dried sponge Pd, the reaction cannot occur in the absence of water. For Pd/C catalyst, minor amount of water reduces the induction time, increases the reaction rate and reaction TOFs. Water might enhance the diffusion, adsorption and dissociation of H2 on Pd catalysts.展开更多
Geometrical optimization and electrostatic potential calculations have been performed for a series of halogenated hydrocarbons at the HF/Gen-6d level. A number of electrostatic potentials and the statistically based s...Geometrical optimization and electrostatic potential calculations have been performed for a series of halogenated hydrocarbons at the HF/Gen-6d level. A number of electrostatic potentials and the statistically based structural descriptors derived from these electrostatic potentials have been obtained. Multiple linear regression analysis and artificial neural network are employed simultaneously in this paper. The result shows that the parameters derived from electrostatic 2 potentials σtot^2, V s and ∑ Vs^＋, together with the molecular volume （Vine） can be used to express the quantitative structure-infinite dilution activity coefficients （γ^∞） relationship of halogenated hydrocarbons in water. The result also demonstrates that the model obtained by using BFGS quasiNewton neural network method has much better predictive capability than that from multiple linear regression. The goodness of the model has been validated through exploring the predictive power for the external test set. The model obtained via neural network may be applied to predict γ^∞ of other halogenated hydrocarbons not present in the data set.展开更多
Halogenated thiophenes are generally used units for constructing organic semiconductor materials for photovoltaic applications.Here,we introduced thiophene,2-bromothiophene,and 2-chlorothiophene units to the central c...Halogenated thiophenes are generally used units for constructing organic semiconductor materials for photovoltaic applications.Here,we introduced thiophene,2-bromothiophene,and 2-chlorothiophene units to the central core of quinoxaline-based acceptors and obtained three acceptors,Qx-H,Qx-Br,and Qx-Cl,respectively.Compared with Qx-H,Qx-Br and Qx-Cl showed enhanced absorption,down-shifted energy levels,improved crystallinity,and reduced energy disorder.The improved crystallinity significantly optimized the blend morphology,leading to efficient charge generation and transport and,therefore,less bimolecular recombination.Eventually,PM6:Qx-Br-based devices exhibited an outstanding power conversion efficiency of 17.42%with a high open-circuit voltage(VOC)of 0.915 V.Furthermore,Y6 was introduced into the PM6:Qx-Br binary system to improve the light utilization,and the resulting ternary devices delivered a high PCE of 18.36%.This study demonstrated the great potential of halogenated thiophene substitution in quinoxaline-based acceptors for building high-performance organic solar cell acceptor materials.展开更多
The effect of glycinebetaine in selectively stabilizing the PSII extrinsic polypeptides was studied with PSII particles treated with different methods. It was shown that glycinebetaine markedly stabilized the PSII ext...The effect of glycinebetaine in selectively stabilizing the PSII extrinsic polypeptides was studied with PSII particles treated with different methods. It was shown that glycinebetaine markedly stabilized the PSII extrinsic polypeptides when the particles were treated with 0.8 mol/L Tris (pH8.0) or high concentrations of NaCl. The stabilizing effect was less pronounced when the PSII particles were treated by heat shock or trichloroacetate (TCA). The capability of halogenated acetates to release extrinsic polypeptides in PSII particles was found to follow the order of decreasing molecular hydrophobicities: trichloroacetate (TCA)> dichloroacetate (DCA)> monoiodoacetate (MIA)>monobromoacetate (MBA)>monochloroacetate (MCA). All these results imply that glycinebetaine is effective in stabilizing biopolymer structure against the action of electrolytes, while it is ineffective in protecting extrinsic polypeptides in PSII particles from dissociation induced by halogenated acetates or heat treatments which disturbed the hydrophobic interactions within the polypeptides.展开更多
The halogenated boron-doped diamond （BDD） surfaces were reacted with sodium azide through a nucle- ophilic substitution reaction. The resulting azide-terminated BDD surfaces were used to trigger the ＂click＂ reacti...The halogenated boron-doped diamond （BDD） surfaces were reacted with sodium azide through a nucle- ophilic substitution reaction. The resulting azide-terminated BDD surfaces were used to trigger the ＂click＂ reaction. Because of the attractive electrochemical properties of ferrocene-containing molecules, such as fast electron transfer rates, reversible redox activities, and favorable redox potentials, we show that ferrocene derivatives can be grafted onto non-oxidized diamond surfaces by ＂click chemistry＂. These redox-active ferrocene-containing layers on a BDD surface, because of their ability to store and release charges reversibly, have the potential to be used as hybrid molecular/semiconductor memory devices.展开更多
A convenient and efficient method was developed for the synthesis of naphtho[2,1-blfurans via 4-dimethylaminopyridine（DMAP）-catalyzed cascade reaction of 2-hydroxy-l-naphthaldehydes and a-halogenated ketones in mode...A convenient and efficient method was developed for the synthesis of naphtho[2,1-blfurans via 4-dimethylaminopyridine（DMAP）-catalyzed cascade reaction of 2-hydroxy-l-naphthaldehydes and a-halogenated ketones in moderate to good yields in the presence of Na2CO3 at 80 ~C for 6 h. The mechanism for this process was briefly discussed with a tentative catalytic cycle proposed. Moreover, this method features organocatalysts and high step-economy, which makes it practical and attractive.展开更多
Treating water contaminants via heterogeneously catalyzed reduction reaction is a subject of growing interest due to its good activity and superior selectivity compared to conventional technology, yielding products th...Treating water contaminants via heterogeneously catalyzed reduction reaction is a subject of growing interest due to its good activity and superior selectivity compared to conventional technology, yielding products that are non-toxic or substantially less toxic. This article reviews the application of catalytic reduction as a progressive approach to treat different types of contaminants in water, which covers hydrodehalogenation for wastewater treatment and hydrogenation of nitrate/nitrite tbr groundwater remediation. For hydrodehalogenation, an overview of the existing treatment technologies is provided with an assessment of the advantages of catalytic reduction over the conventional methodologies. Catalyst design for feasible catalytic reactions is considered with a critical analysis of the pertinent literature. For hydrogenation, hydrogenation of nitrate/nitrite contaminants in water is mainly focused. Several important nitrate reduction catalysts are discussed relating to their preparation method and catalytic performance. In addition, novel approach of catalytic reduction using in situ synthesized H2 evolved from water splitting reaction is illustrated. Finally, the challenges and perspective tbr the extensive application of catalytic reduction technology in water treatment arc discussed. This review provides key information to our community to apply catalytic reduction approach for water treatment.展开更多
The capacity factors （k＇） of fourteen types ofhalogenated thiophenols in different phases of methanol-water eluent were determined by reversed phased high-performance liquid chromatography （RP-HPLC） and the relat...The capacity factors （k＇） of fourteen types ofhalogenated thiophenols in different phases of methanol-water eluent were determined by reversed phased high-performance liquid chromatography （RP-HPLC） and the relationships between the logarithm of capacity factor lgK＇ and methanol ratio ψ were analyzed. A fair linear relationship is found between lgK＇ and ψ, and the correlation coefficients R2 of the constructed linear equations are all greater than 0.990. Relationship between the chromatographic data lgKw＇ when extrapolated to pure water and n-octanol/water partition coefficient lgKow obtained by the group contribution method has shown a good linear correlation with R2= 0.956. The structure parameters of fourteen halogenated thiophenols were calculated by using DFT, and the correlation equation of lgKw＇ and structure parameters was obtained by using SPSS, lgKw＇ = -0.409 ＋ 0.039a and R2 = 0.981, meaning that lgKw＇ is mainly determined by the polarizability α.展开更多
A phenoxazine based molecule termed SP has been synthesized and used as selective sensor for halogenated solvents. This molecule shows selective fast response towards halogenated solvent via naked-eye detectable chrom...A phenoxazine based molecule termed SP has been synthesized and used as selective sensor for halogenated solvents. This molecule shows selective fast response towards halogenated solvent via naked-eye detectable chromism. SP shows colorless solution when dissolved in most solvents initially but changes to blue color in chloroform under UV irradiation(λ = 365 nm) within 5 s. The luminescence spectra of SP in halogenated solvent show a large bathochromic shift(> 100 nm) with 60-fold enhanced emission intensity compared to that in halogen-free solvents. It is also worth mentioning that the photoinduced reaction between SP molecule and the halogenated solvents occurred. Based on the detailed NMR, fluorescence and mass spectra, the possible radical reaction mechanism was proposed.Different from the majority of solvatochromic sensors that based on the polarity of solvents for detection of halogenated solvents, our sensor system worked in a special展开更多
"One-step"method for the synthesis of secondary aliphatic amine substituted nitrobenzaldehyde was developed.In the presence of Pd catalyst,halogenated nitrobenzaldehyde could be smoothly coupled with seconda..."One-step"method for the synthesis of secondary aliphatic amine substituted nitrobenzaldehyde was developed.In the presence of Pd catalyst,halogenated nitrobenzaldehyde could be smoothly coupled with secondary aliphatic amine to give the target product in hexamethylphosphamide(HMPT) media without the protection of aldehyde groups.展开更多
基金supported by the National Natural Science Foundation of China(201573136,U1510105)the Scientific Research Start-up Funds of Shanxi University(RSC723)~~
文摘Due to the advantages of high surface areas, large pore volumes and pore sizes, abundant nitrogen content that favored the metal-support interactions, N-doped ordered mesoporous carbons are regarded as a kind of fascinating and potential support for the synthesis of effective supported cat-alysts. Here, a N-doped ordered mesoporous carbon with a high N content （9.58 wt%）, high surface area （417 m^2/g）, and three-dimensional cubic structure was synthesized successfully and used as an effective support for immobilizing Pt nanoparticles （NPs）. The positive effects of nitrogen on the metal particle size enabled ultrasmall Pt NPs （about 1.0 ± 0.5 nm） to be obtained. Moreover, most of the Pt NPs are homogeneously dispersed in the mesoporous channels. However, using the ordered mesoporous carbon without nitrogen as support, the particles were larger （4.4 ± 1.7 nm） and many Pt NPs were distributed on the external surface, demonstrating the important role of the nitrogen species. The obtained N-doped ordered mesoporous material supported catalyst showed excellent catalytic activity （conversion 100%） and selectivity （〉99%） in the hydrogenation of halogenated nitrobenzenes under mild conditions. These values are much higher than those achieved using a commercial Pt/C catalyst （conversion 89% and selectivity 90%）. This outstanding catalytic perfor-mance can be attributed to the synergetic effects of the mesoporous structure, N-functionalized support, and stabilized ultrasmall Pt NPs. Moreover, such supported catalyst also showed excellent catalytic performance in the hydrogenation of other halogenated nitrobenzenes and nitroarenes. In addition, the stability of the multifunctional catalyst was excellent and it could be reused more than 10 times without significant losses of activity and selectivity. Our results conclusively show that a N-doped carbon support enable the formation of ultrafine metal NPs and improve the reaction ac-tivity and selectivity.
基金supported by the Strategic Priority Research Program of CAS(No.XDB01020300)NSF China Grants(Nos.21577149,21477139,21237005 and 21321004)NIH Grants(Nos.ES11497,RR01008 and ES00210)
文摘The ubiquitous distribution of halogenated aromatic compounds（XAr） coupled with their carcinogenicity has raised public concerns on their potential risks to both human health and the ecosystem. Recently, advanced oxidation processes（AOPs） have been considered as an＂environmentally-friendly＂ technology for the remediation and destruction of such recalcitrant and highly toxic XAr. During our study on the mechanism of metal-independent production of hydroxyl radicals（UOH） by halogenated quinones and H_2O_2, we found, unexpectedly, that an unprecedented UOH-dependent two-step intrinsic chemiluminescene（CL） can be produced by H_2O_2 and tetrachloro-p-benzoquinone, the major carcinogenic metabolite of the widely used wood preservative pentachlorophenol. Further investigations showed that, in all UOH-generating systems, CL can also be produced not only by pentachlorophenol and all other halogenated phenols, but also by all XAr tested. A systematic structure–activity relationship study for all 19 chlorophenolic congeners showed that the CL increased with an increasing number of Cl-substitution in general. More importantly, a relatively good correlation was observed between the formation of quinoid/semiquinone radical intermediates and CL generation. Based on these results, we propose that UOH-dependent formation of quinoid intermediates and electronically excited carbonyl species is responsible for this unusual CL production; and a rapid, sensitive,simple, and effective CL method was developed not only to detect and quantify trace amount of XAr, but also to provide useful information for predicting the toxicity or monitoring real-time degradation kinetics of XAr. These findings may have broad chemical, environmental and biological implications for future studies on halogenated aromatic persistent organic pollutants.
基金supported by the National Natural Science Foundation of China(20977046, 20737001) the Natural Science Foundation of Zhejiang Province(2007Y507280)
文摘In this paper we take photobacterium phosphoreum （T3） as the experimental bacteria, and determine the half-inhibitory concentration （-1gEC50） against the photobacterium phosphoreum of 16 halogenated benzenes. Using B3LYP method of DFT in the Gaussian 03 program, we obtain the structural and thermodynamic descriptors of 16 halogenated benzenes by fully-optimized calculation at the 6-311G＊＊ level. Taking the structural and thermodynamic descriptors as theoretical descriptors, the 2D QSAR model （R2 = 0.983） was established, which can be utilized to predict -lgEC50 of halogenated benzene according to the corrected linear solvation energy theory based on the experimental data of-lgECs0. In addition, the relationship between the toxicity and 3D spatial structure of the compound is studied by comparing the molecular similarity index analysis （CoMSIA） of 3D-QSAR method. By cross validation, the correlation coefficient q2 of CoMSIA model is 0.687, and the conventional correlation coefficient R2 = 0.958. The model is stable and reliable with great predictive ability. The 3D-QSAR model shows that the toxicity of halogenated benzene compound is mainly affected by the characteristics of hydrophobie field of the substituted halogens.
文摘Environmental water samples can be extremely complex,with potentially thousands of molecules that can derive from natural organic matter（NOM）and thousands that derive from anthropogenic contaminants.As complex as these samples are,drinking water can be even more complex.Due to disinfectants that are used to treat drinking water（e.g.,chlorine,chloramines,
基金This work was supported by the National Natural Science Foundation of China (No. 20502022) and the Ph.D. Fund of Ningbo ( No. 2004A610010)
文摘Halogenated methyl-phenyl ethers （anisoles） are ubiquitous organic compounds in the environment. In the present study, geometrical optimization and electrostatic potential calculations have been performed for 42 halogenated anisoles at the HF/6-31 G^＊ level. A number of statistically based parameters have been obtained. By multiple regression method, linear relationships between the gas-chromatographic relative retention time （RRT） and structural descriptors have been established for the training set of 32 halogenated anisoles. The result showed that the parameters derived from electrostatic potentials （ESPs） together with the molecular volume （Vmc） could be well used to express the quantitative structure-RRT relationships of halogenated anisoles. The best two-variable regression model gives a correlation coefficient of 0.980 and a standard deviation of 0.07, and the leave-one-out cross-validated correlation coefficient is 0.975. The goodness of the model has been further validated through exploring the predictive power for the testing set of 10 halogenated anisoles.
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(R2=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
文摘Ensuring the health and safety of drinking water is crucial for both nations and their citizens.Since the 20th century,the disinfection of drinking water,effectively controlling pathogens in water sources,has become one of the significant advances in public health.However,the disinfectants used in the process,such as chlorine and chlorine dioxide,react with natural organic matter in the water to produce disinfection by-products(DBPs).Most of these DBPs contain chlorine,and if the source water contains bromine or iodine,brominated or iodinated DBPs,collectively referred to as Halogenated disinfection byproducts(X-DBPs),are formed.Numerous studies have found that X-DBPs pose potential risks to human health and the environment,leading to widespread concern.Mass spectrometry has become an important means of discovering new types of X-DBPs.This paper focuses on the study of methods for analyzing X-DBPs in drinking water using mass spectrometry.
基金supported by the National Natural Science Foundation of China(Nos.20976164,21176221 and 21136001)National Basic Research Program of China(973 Program)(Nos. 2011CB710803,2013CB733500)Zhejiang Provincial Natural Science Foundation of China(No.LY12B03005)
文摘This study shows that minor amount of water plays a very important role in solvent-free hydrogenation of halogenated nitrobenzenes. For dried sponge Pd, the reaction cannot occur in the absence of water. For Pd/C catalyst, minor amount of water reduces the induction time, increases the reaction rate and reaction TOFs. Water might enhance the diffusion, adsorption and dissociation of H2 on Pd catalysts.
文摘Geometrical optimization and electrostatic potential calculations have been performed for a series of halogenated hydrocarbons at the HF/Gen-6d level. A number of electrostatic potentials and the statistically based structural descriptors derived from these electrostatic potentials have been obtained. Multiple linear regression analysis and artificial neural network are employed simultaneously in this paper. The result shows that the parameters derived from electrostatic 2 potentials σtot^2, V s and ∑ Vs^＋, together with the molecular volume （Vine） can be used to express the quantitative structure-infinite dilution activity coefficients （γ^∞） relationship of halogenated hydrocarbons in water. The result also demonstrates that the model obtained by using BFGS quasiNewton neural network method has much better predictive capability than that from multiple linear regression. The goodness of the model has been validated through exploring the predictive power for the external test set. The model obtained via neural network may be applied to predict γ^∞ of other halogenated hydrocarbons not present in the data set.
基金We acknowledge the financial support provided by the National Natural Science Foundation of China(No.51973043)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB36000000).
文摘Halogenated thiophenes are generally used units for constructing organic semiconductor materials for photovoltaic applications.Here,we introduced thiophene,2-bromothiophene,and 2-chlorothiophene units to the central core of quinoxaline-based acceptors and obtained three acceptors,Qx-H,Qx-Br,and Qx-Cl,respectively.Compared with Qx-H,Qx-Br and Qx-Cl showed enhanced absorption,down-shifted energy levels,improved crystallinity,and reduced energy disorder.The improved crystallinity significantly optimized the blend morphology,leading to efficient charge generation and transport and,therefore,less bimolecular recombination.Eventually,PM6:Qx-Br-based devices exhibited an outstanding power conversion efficiency of 17.42%with a high open-circuit voltage(VOC)of 0.915 V.Furthermore,Y6 was introduced into the PM6:Qx-Br binary system to improve the light utilization,and the resulting ternary devices delivered a high PCE of 18.36%.This study demonstrated the great potential of halogenated thiophene substitution in quinoxaline-based acceptors for building high-performance organic solar cell acceptor materials.
文摘The effect of glycinebetaine in selectively stabilizing the PSII extrinsic polypeptides was studied with PSII particles treated with different methods. It was shown that glycinebetaine markedly stabilized the PSII extrinsic polypeptides when the particles were treated with 0.8 mol/L Tris (pH8.0) or high concentrations of NaCl. The stabilizing effect was less pronounced when the PSII particles were treated by heat shock or trichloroacetate (TCA). The capability of halogenated acetates to release extrinsic polypeptides in PSII particles was found to follow the order of decreasing molecular hydrophobicities: trichloroacetate (TCA)> dichloroacetate (DCA)> monoiodoacetate (MIA)>monobromoacetate (MBA)>monochloroacetate (MCA). All these results imply that glycinebetaine is effective in stabilizing biopolymer structure against the action of electrolytes, while it is ineffective in protecting extrinsic polypeptides in PSII particles from dissociation induced by halogenated acetates or heat treatments which disturbed the hydrophobic interactions within the polypeptides.
基金The National Nature Science Foundation of China(Nos.51002090 and 50972078)the Outstanding Young Scientist Research Award Fund of Shandong Province(No.BS2010CL028)were gratefully acknowledged for financial support
文摘The halogenated boron-doped diamond （BDD） surfaces were reacted with sodium azide through a nucle- ophilic substitution reaction. The resulting azide-terminated BDD surfaces were used to trigger the ＂click＂ reaction. Because of the attractive electrochemical properties of ferrocene-containing molecules, such as fast electron transfer rates, reversible redox activities, and favorable redox potentials, we show that ferrocene derivatives can be grafted onto non-oxidized diamond surfaces by ＂click chemistry＂. These redox-active ferrocene-containing layers on a BDD surface, because of their ability to store and release charges reversibly, have the potential to be used as hybrid molecular/semiconductor memory devices.
基金Supported by the National Natural Science Foundation of China（Nos.21172001, 21372008）, the Program for the New Century Excellent Talents in University of China（No.NCET-10-0004） and the Natural Science Foundation of Anhui Province of China（No. 1308085QB39）.
文摘A convenient and efficient method was developed for the synthesis of naphtho[2,1-blfurans via 4-dimethylaminopyridine（DMAP）-catalyzed cascade reaction of 2-hydroxy-l-naphthaldehydes and a-halogenated ketones in moderate to good yields in the presence of Na2CO3 at 80 ~C for 6 h. The mechanism for this process was briefly discussed with a tentative catalytic cycle proposed. Moreover, this method features organocatalysts and high step-economy, which makes it practical and attractive.
文摘Treating water contaminants via heterogeneously catalyzed reduction reaction is a subject of growing interest due to its good activity and superior selectivity compared to conventional technology, yielding products that are non-toxic or substantially less toxic. This article reviews the application of catalytic reduction as a progressive approach to treat different types of contaminants in water, which covers hydrodehalogenation for wastewater treatment and hydrogenation of nitrate/nitrite tbr groundwater remediation. For hydrodehalogenation, an overview of the existing treatment technologies is provided with an assessment of the advantages of catalytic reduction over the conventional methodologies. Catalyst design for feasible catalytic reactions is considered with a critical analysis of the pertinent literature. For hydrogenation, hydrogenation of nitrate/nitrite contaminants in water is mainly focused. Several important nitrate reduction catalysts are discussed relating to their preparation method and catalytic performance. In addition, novel approach of catalytic reduction using in situ synthesized H2 evolved from water splitting reaction is illustrated. Finally, the challenges and perspective tbr the extensive application of catalytic reduction technology in water treatment arc discussed. This review provides key information to our community to apply catalytic reduction approach for water treatment.
文摘The capacity factors （k＇） of fourteen types ofhalogenated thiophenols in different phases of methanol-water eluent were determined by reversed phased high-performance liquid chromatography （RP-HPLC） and the relationships between the logarithm of capacity factor lgK＇ and methanol ratio ψ were analyzed. A fair linear relationship is found between lgK＇ and ψ, and the correlation coefficients R2 of the constructed linear equations are all greater than 0.990. Relationship between the chromatographic data lgKw＇ when extrapolated to pure water and n-octanol/water partition coefficient lgKow obtained by the group contribution method has shown a good linear correlation with R2= 0.956. The structure parameters of fourteen halogenated thiophenols were calculated by using DFT, and the correlation equation of lgKw＇ and structure parameters was obtained by using SPSS, lgKw＇ = -0.409 ＋ 0.039a and R2 = 0.981, meaning that lgKw＇ is mainly determined by the polarizability α.
基金the Natural Science Foundation of Shandong Province (Nos. BS2014CL042, ZR2014EEP021, ZR2017MB033)the Key Research and Development Program of Shandong Province, China (Nos. 2016GSF116014 and 2017CXGC1113)+1 种基金the Start-up Grant of Shandong Jiaotong University and the National Undergraduate Innovation Training Program (No. 201611510109)the financial support from the government of Shandong Province for visiting abroad
文摘A phenoxazine based molecule termed SP has been synthesized and used as selective sensor for halogenated solvents. This molecule shows selective fast response towards halogenated solvent via naked-eye detectable chromism. SP shows colorless solution when dissolved in most solvents initially but changes to blue color in chloroform under UV irradiation(λ = 365 nm) within 5 s. The luminescence spectra of SP in halogenated solvent show a large bathochromic shift(> 100 nm) with 60-fold enhanced emission intensity compared to that in halogen-free solvents. It is also worth mentioning that the photoinduced reaction between SP molecule and the halogenated solvents occurred. Based on the detailed NMR, fluorescence and mass spectra, the possible radical reaction mechanism was proposed.Different from the majority of solvatochromic sensors that based on the polarity of solvents for detection of halogenated solvents, our sensor system worked in a special
基金financial support by the open project program of Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education of China(No.09HJYH04)Hunan Science & Technology Department Project(No.2009FJ3166)
文摘"One-step"method for the synthesis of secondary aliphatic amine substituted nitrobenzaldehyde was developed.In the presence of Pd catalyst,halogenated nitrobenzaldehyde could be smoothly coupled with secondary aliphatic amine to give the target product in hexamethylphosphamide(HMPT) media without the protection of aldehyde groups.
