To further elucidate interaction of nitroaromatic compounds with mineral surface, the sorption of m-dinitrobenzene (m-DNB) and nitrobenzene to original bentonite in aqueous solution containing different electrolytes...To further elucidate interaction of nitroaromatic compounds with mineral surface, the sorption of m-dinitrobenzene (m-DNB) and nitrobenzene to original bentonite in aqueous solution containing different electrolytes (i.e., KCl, NH4Cl, CaCl2 and Tetramethylammonium bromide (TMAB)) was studied. The sorption of m-DNB was greatly enhanced with the presence of KCl and NH4Cl, while little influence was observed with CaCl2 and TMAB, following the order of KCl 〉 NH4Cl 〉〉 TMAB, CaCl2, or DI water. For nitrobenzene, sorption enhancement only occurred at high nitrobenzene concentrations in the presence of KCl, and the solute equilibrium concentration at inflexion point was lowered with increasing KCl concentration. These sorption enhancements were significantly promoted with the increase of electrolyte concentration. The salting-out effect is insufficient to account for the sorption enhancement by original bentonite with increasing KCI or NH4Cl concentration. X-ray diffraction patterns of bentonite suspensions indicated that the sorption enhancement of m-DNB was attributed to the intercalation of K^+ or NH4^+ into bentonite interlayer and then dehydration with m-DNB to form inner-sphere complexes, which caused previously expanded bentonite interlayers to collapse in aqueous suspension, thus further enhanced the interaction of phenyl with siloxane surface. In comparison, the sorption enhancement of NB is attributed to the formation of outer-sphere complexes with K^+ at high solute-loadings (〉 20(0-400 mg/kg). The sorption of m-DNB to initially modified TMA^+-bentonite and K^+-bentonite was almost the same as respective sorption to original bentonite in solution containing TMA^+ and K^+.展开更多
The three-dimensional holographic vector of atomic interaction field(3D-Ho VAIF) is used to characterize the molecular structures of 45 nitroaromatic compounds.Two quantitative structure-toxicity relationship(QSAR...The three-dimensional holographic vector of atomic interaction field(3D-Ho VAIF) is used to characterize the molecular structures of 45 nitroaromatic compounds.Two quantitative structure-toxicity relationship(QSAR) models are built up by stepwise regression(SMR),multiple linear regression(MLR) and partial least-squares regression(PLS).The correlation coefficients(R) of the models are 0.960 and 0.961,respectively.Then the models are evaluated by performing the cross-validation with the leave-one-out(LOO) procedure and the correlation coefficients(RCV) are 0.949 and 0.941,respectively.The results show that the descriptors can successfully describe the structures of organic compounds.The stability and predictability of the model are satisfactory.展开更多
In the present study,geometrical optimization and electrostatic potential calcula-tions have been performed for 22 nitroaromatic compounds at the HF/6-31G level of theory.A number of statistically based parameters hav...In the present study,geometrical optimization and electrostatic potential calcula-tions have been performed for 22 nitroaromatic compounds at the HF/6-31G level of theory.A number of statistically based parameters have been obtained.Linear relationship between the decomposition enthalpy(taken as a macroscopic property related to explosibility) of nitroaromatic compounds and the structural descriptors have been established by multiple regression method.The result shows that the quantities derived from electrostatic potentialsΣ V sind+,,Vsind- and Vs,max can be well used to express the quantitative structure-decomposition enthalpy relationship of nitroa-romatic compounds,which proves the general applicability of this parameter set to a great extent.Good predictive capabilities have also been demonstrated.展开更多
The bimetallic nanoparticles compositing of Ni-rich core and Cu-rich shell(Ni/Cu NPs)were successfully synthesized by a liquid-phase thermal decomposition method.The content of copper and nickel in Ni/Cu NPs was contr...The bimetallic nanoparticles compositing of Ni-rich core and Cu-rich shell(Ni/Cu NPs)were successfully synthesized by a liquid-phase thermal decomposition method.The content of copper and nickel in Ni/Cu NPs was controllable by adjusting the ratio of two metal precursors,copper formate(Cuf)and nickel acetate tetrahydrate(Ni(OAc)_(2)·4H_(2)O).Ni/Cu NPs were further anchored on graphene oxide(GO)to prepare a magnetic composite catalyst,called Ni/Cu-GO.The dispersibility of Ni/Cu NPs in solution was enhanced by GO anchoring to prevent the sintering and aggregation during the reaction process,thereby ensuring the catalytic and cycling performance of the catalyst.The catalytic transfer hydrogenation(CTH)reaction of nitroaromatics was investigated when ammonia borane was used as the hydrogen source.Cu dominated the main catalytic role in the reaction,while Ni played a synergistic role of catalysis and providing magnetic properties for separation.The Ni_(7)/Cu_(3)-GO catalyst exhibited the best catalytic performance with the conversion and yield of 99%and 96%,respectively,when 2-methyl-5-nitrophenol was used as the substrate.The Ni_(7)/Cu_(3)-GO catalyst also exhibited excellent cyclic catalytic performance with the 5-amino-2-methylphenol yield of above 90%after six cycles.In addition,the Ni_(7)/Cu_(3)-GO catalyst could be quickly recycled by magnetic separation.Moreover,the Ni_(7)/Cu_(3)-GO catalyst showed good catalytic performance for halogen-containing nitroaromatics without dehalogenation.展开更多
Nitroaromatic compounds were reductively metabolized to the corresponding amine compounds via the intermediate hydroxylamines by liver microsomes from pig,rat,chook,cattle,sheep,paralichthys olivaceus and cyprinoid in...Nitroaromatic compounds were reductively metabolized to the corresponding amine compounds via the intermediate hydroxylamines by liver microsomes from pig,rat,chook,cattle,sheep,paralichthys olivaceus and cyprinoid in varied reactivity.Similar with baker's yeast,the pig,rat and sheep liver microsomes exhibited high reactivity toward 4-nitro-1,2-dicyanbenzen(1a),while the cyprinoid liver microsomes were inefficient.Contrasted to compound 1a,monocyannitrobenzene(2a) was difficult to reduce by pig liver microsomes.In opposition to grape cells,pig liver microsomes exhibited activities toward some aromatic hydroxylamine compounds.展开更多
In general, many pollutants co\|exist in natural aquatic ecosystems. They affect each other and occur different results, such as synergism, addition and antagonism. So the research at mixtoxicity of contaminants to aq...In general, many pollutants co\|exist in natural aquatic ecosystems. They affect each other and occur different results, such as synergism, addition and antagonism. So the research at mixtoxicity of contaminants to aquatic organism is more important than monotoxicity. In this paper, 50% effectual inhibition concentration 48h \%EC\%\-\{50\} values of 6 kinds of nitroaromatic compounds to the green algae, \%Scenedesmus obliquus,\% were investigated. Mixtoxic experiments, in which any combination of 2,4\|DNT and other 6 kinds of compounds, indicate: (1) synergisms between 2,4\|DNT and 4\|NAn, as well as 4\|NAnis, 1,4\|DNB; (2) antagonisms between 2,4\|DNT and 4\|NT, as well as 4\|NPh, 4\|NCB.展开更多
Quantitative structure-property relationships(QSPRs) have been developed to predict the thermal stability for a set of 22 nitroaromatic compounds by means of the theoretical descriptors derived from electrostatic po...Quantitative structure-property relationships(QSPRs) have been developed to predict the thermal stability for a set of 22 nitroaromatic compounds by means of the theoretical descriptors derived from electrostatic potentials on molecular surface. Several techniques, including partial least squares regression(PLS), least-squares support vector machine(LSSVM) and Gaussian process(GP) have been utilized to establish the relationships between the structural descriptor and the decomposition enthalpy. The nonlinear LSSVM and GP models have proven to own a better predictive ability than the linear PLS method. Moreover, owing to its ability to handle both linear- and nonlinear-hybrid relationship, GP gives a stronger fitting ability and a better predictive power than LSSVM, and therefore could be well applied to developing QSPR models for the thermal stability of nitroaromatic explosives.展开更多
Luminescent hydrogels have received considerable attention in the application of sensors.Nitroaro matics are harmful to human health and can be carcinogenic.Some skin allergies and central nervous system injuries may ...Luminescent hydrogels have received considerable attention in the application of sensors.Nitroaro matics are harmful to human health and can be carcinogenic.Some skin allergies and central nervous system injuries may also be attributed to the over exposure to nitroaromatics.Thus,nitroaromatics sensor with fast detection and low detection limit is highly desirable.Herein,novel tough hydrogels were prepared by introducing hydrogen bonds and covalent bonds into the interpenetrating networks of modified chitosan and poly(vinyl alcohol)(PVA) via frozen-thawing induced chemical cross-linking.The synthesized hydrogels exhibit high mechanical strength(0.23 MPa tensile strength at 140% tensile strain,1.0 MPa compressive strength at 80% compressive strain).Strong green emission was realized by energy transfer from the modified chitosan to Tb^(3+)via the so-called "antenna effect." The prepared luminescent hydrogels show an excellent detection effect on nitroaromatic compounds and its detection limit can reach ppm-level.The hydrogels also exhibit good reversibility and a fast "off-on" fluorescence switching process.This work may open up a new way for the development of stable,rapid,and reusable sensors for the detection of harmful nitroaromatics.展开更多
Catalysts for chemoselective hydrogenation are of vital importance for the synthesis of various important chemicals and intermediates.Herein we developed a simple method for preparing a highly efficient Ni-MoC_(x)nano...Catalysts for chemoselective hydrogenation are of vital importance for the synthesis of various important chemicals and intermediates.Herein we developed a simple method for preparing a highly efficient Ni-MoC_(x)nanocomposite catalyst via temperature-programmed carburization of a polyoxometalate precursor.X-ray diffraction(XRD),scanning transmission electron microscopy(STEM),X-ray photoelectron spectroscopy(XPS),and X-ray absorption spectroscopy(XAS)analyses indicate that the resulting mesoporous nanocomposite catalyst is made up of well-dispersed metallic nickel particles embedded in a MoC_(x)matrix.This catalyst exhibits high activity and selectivity(>99%)in the hydrogenation of various substituted nitroaromatics to corresponding anilines.The high efficiency is attributed to the intimate contact of the constituents favoring electron transfer and hydrogen adsorption.Dihydrogen is physisorbed on the carbide support and dissociates on the nickel particles,as evidenced by Mo K-edge X-ray absorption near-edge structure(XANES)spectra,density functional theory(DFT),and hydrogen-deuterium exchange.The remarkable catalytic performance of the catalyst could be traced back to the synergistic interaction between the Ni particles and the carbide support.In-situ infrared spectroscopy and DFT simulations indicated that the adsorption/activation of the nitro group is favored compared to that of other substituents at the aromatic ring.In recyclability tests,the Ni-MoC_(x)nanocomposite showed no significant loss of catalytic performance in seven consecutive runs,indicating its robust nature.展开更多
Herein,we report a new metal-organic framework with an AIE ligand (H_(4)TCPP=2,3,5,6-tetra-(4-carboxyphenyl)pyrazine) and Mg^(2+) ions,that is,[Mg_(2)(H_(2)O)_(4)TCPP]·DMF·5CH_(3)CN (Mg-TCPP,TCPP=tetra-(4-ca...Herein,we report a new metal-organic framework with an AIE ligand (H_(4)TCPP=2,3,5,6-tetra-(4-carboxyphenyl)pyrazine) and Mg^(2+) ions,that is,[Mg_(2)(H_(2)O)_(4)TCPP]·DMF·5CH_(3)CN (Mg-TCPP,TCPP=tetra-(4-carboxyphenyl)pyrazine) for detection of nitroaromatic explosives.Due to the coordination effect and restricted intramolecular rotation,Mg-TCPP exhibits bright blue light.As a fluorescent sensor,Mg-TCPP exhibits high selectivity and sensitivity for sensing 2,4,6-trinitrophenol (TNP) by quenching behaviors with the Stern-Volmer quenching constant (K_(SV)) of 3.63×10^(5)L/mol and achieves the low limit of detection of 25.6 ppb,which is beyond most of the previously reported fluorescent materials.Notably,the portable Mg-TCPP films are prepared and it can be used for rapid and sensitive TNP detection in a variety of environments including organic solvent and aqueous solution.Moreover,TNP vapor can be detected within 3 min by naked eye and the film could be regenerated under simple solvent cleaning.展开更多
Nitroaromatics are typical toxic organic pollutants and are ubiquitous in environment with diverse structures. They are widely used in many industries and formed during many natural and anthropogenic processes. Most o...Nitroaromatics are typical toxic organic pollutants and are ubiquitous in environment with diverse structures. They are widely used in many industries and formed during many natural and anthropogenic processes. Most of these pollutants are potentially carcinogenic and the as-sessment and prediction of the mutagenicity of nitroaromatics are of great interest. In this paper the structure-mutagenicity relationships of 219 nitroaromatics are investigated by molecular or-bital theory based classic structure-activity relationships and comparative molecular field analysis (CoMFA). A comparison is undertaken in respect of the interpretation of mechanism and predic-tive ability for these two categories of QSAR approaches and highly predictive QSAR models have been developed.展开更多
Heterogeneous iridium catalysts were prepared and applied for the reductive amination of aldehydes and ketones with nitroaromatics and amines using H2. The iridium catalysts were prepared by pyrolysis of ionic liquid ...Heterogeneous iridium catalysts were prepared and applied for the reductive amination of aldehydes and ketones with nitroaromatics and amines using H2. The iridium catalysts were prepared by pyrolysis of ionic liquid 1-methyl-3-cyanomethylimidazoulium chloride ([MCNI]C1) with iridium chloride (IrC13) in activated carbons. Iridium particles were well dispersed and stable in the N-doped carbon materials from [MCNI]C1 with activated carbon. The Ir@NC(600-2h) catalyst was found to be highly active and selective for the reductive amination of aldehydes and ketones using H2 and a variety of nitrobenzenes and amines were selectively converted into the corresponding secondary and tertiary amines. The Ir@NC(600-2h) catalyst can be reusable several times without evident deactivation.展开更多
The DFT-B3LYP method, with the basis set 6-311G, was employed to calculate the molecular geometries and electronic structures of 31 nitroaromatics. EHOMO, ELUMO, QC, QN. QNO2 and μ were selected as quantum chemical d...The DFT-B3LYP method, with the basis set 6-311G, was employed to calculate the molecular geometries and electronic structures of 31 nitroaromatics. EHOMO, ELUMO, QC, QN. QNO2 and μ were selected as quantum chemical descriptors. The acute toxicity (-lg LC50) of these compounds to the fathead minnow along with the six descriptors was used to establish the quantitative structure-activity relationships (QSARs), Through stepwise multiple linear regression analysis, a model was established as follows: -lg LC50=9.524-39.527ELUMO+16.859EHOMO+15.130QNO2+4.166QC (n=28, R=0.912, SE=0.361, F=28.468). The model was applied to predict and elucidate the toxicity of nitroaromatics successfully. Furthermore, a metabolic route of nitroaromatics in fathead minnow was proposed.展开更多
Three cadmium(II) metal-organic frameworks(MOFs) based on tetracarboxylate ligands, namely[Cd_2(TTTA)(DMF)_3]·2 DMF(1),[Cd_2(TB)(H_2O)_4]·3DMF·H_2O(2)and [Cd(TEB)_(0.5)].2 DMF.4 H_2O(3) have been design...Three cadmium(II) metal-organic frameworks(MOFs) based on tetracarboxylate ligands, namely[Cd_2(TTTA)(DMF)_3]·2 DMF(1),[Cd_2(TB)(H_2O)_4]·3DMF·H_2O(2)and [Cd(TEB)_(0.5)].2 DMF.4 H_2O(3) have been designed and synthesized. Complex 1 is a 2-dimensional(2 D) 3,4-connected network with 3,4 L13 topology, complex 2 features a 3-dimensional(3D) 3,4-connected tfa topology with a 2-fold interpenetrating structure and complex 3 has a 3D 4-connected dia topology with a 4-fold interpenetrating structure. Interestingly, 2 exhibits permanent pores and selective adsorption of CO_2 over CH_4. In addition, 2 shows fluorescence sensing of Fe^(3+) ion and rapid detection of nitroaromatic compounds(NACs) through fluorescence quenching.展开更多
Herein we describe the development of a homogeneous assay for the detection of 4-nitroaniline(4-NA)and 2,4-dinitroaniline(2,4-diNA).Thisassay relies on fluorescent molecularly imprinted nanoparticles(nano MIPs)which,u...Herein we describe the development of a homogeneous assay for the detection of 4-nitroaniline(4-NA)and 2,4-dinitroaniline(2,4-diNA).Thisassay relies on fluorescent molecularly imprinted nanoparticles(nano MIPs)which,upon interaction with the target analytes,generate areduction in fluorescence emission intensity(quenching).This is due to a resp on sive fluorescent monomer(N-2-propenyl-(5-dimethylamino)-1-naphthalene sulphonamide)employed in the manufacture of the nanoMIPs which,by virtue of the imprinting process,is capable of selectiveinteraction with the target an alyte,thus giving rise to a quenching effect.Selectivity experiments showed excellent recognition propertiestoward the target molecule.Under optimal conditions,the fluorescence intensity of these nano MIPs decreased as the concentration of theimprinted analyte increased from 10 nM to 2.71 pM.A linear relation between the negative logarithm of 4-NA or 2,4-diNA concentrations and the fluorescence intensity for both nanosystems was found(R^2=0.991 and R^2=0.9895),with excellent sensitivity(limit of detection(LOD)=7 and 6 nM,respectively).Furthermore,both nanosystems have been successfully applied for detection of 4-NA or 2,4-diNA in tap water,withrecoveries between 90%to 100.6%and 92%to 100.3%,respectively.Thanks to the versatility of the imprinting process,this nanosystemholds the potential for further development of several optical sensors for many other compounds.展开更多
Two Co(II)-MOFs with different structures were successfully synthesized under the premise of designing two ligands containing alkynyl functional groups. Complexes 1 ([Co(TEPA)(TPT)2/3]·2DMF·H2O) and 2 ([Co(E...Two Co(II)-MOFs with different structures were successfully synthesized under the premise of designing two ligands containing alkynyl functional groups. Complexes 1 ([Co(TEPA)(TPT)2/3]·2DMF·H2O) and 2 ([Co(EPA)(TPT)]·1.5DMF·1.5H2O) show excellent luminescence properties. Meanwhile, as fluorescent sensors, complexes 1 and 2 exhibit selectivity and sensitivity for Fe3+ with the Ksv of 1.520 ×104 L/mol and 3.543 ×104 L/mol, which can rapidly detect nitroaromatic compounds in methanol and ethanol, especially for 2,4-NPH through fluorescence quenching with high quenching efficiency. In particular, the Ksv value of complexes 1 and 2 towards 2,4-NPH can reach up to 1.627 ×105 L/mol and 9.600 ×104 L/mol, demonstrating that complexes 1 and 2 are good candidates for the identification and detection of Fe3+and nitroaromatic compounds.展开更多
The 3-D relationships between the structures of 25 nitroaromatic compounds and their toxicities have been investigated using the comparative molecular field analysis (CoMFA) method, and a 3-D QSAR model with considera...The 3-D relationships between the structures of 25 nitroaromatic compounds and their toxicities have been investigated using the comparative molecular field analysis (CoMFA) method, and a 3-D QSAR model with considerable prediction ability is obtained. In comparison with traditional 2-D techniques, CoMFA helps to give a better interpretation of toxic mechanism of tested compounds.展开更多
Ti3C2Tx has been emerging as an attractive platform to prepare composite catalysts,and their assembly into integrated catalytic mate rials repre sents a key step forward toward practical applications.Howeve r,the swel...Ti3C2Tx has been emerging as an attractive platform to prepare composite catalysts,and their assembly into integrated catalytic mate rials repre sents a key step forward toward practical applications.Howeve r,the swelling behavior of Ti3C2Tx leads to significant structure change,which challenges the stability of Ti3C2Tx-based integrated functional materials for catalytic applications.Here we report a facile synthesis of Pd/Ti3C2Tx■graphene hydrogels in which Pd/Ti3C2Tx are spatially encapsulated in the 3 D porous graphene framework.The porous interconnected structure not only affords efficient mass transfer and desirable functional accessibility to catalytic active sites,but also effectively buffers the swelling behavior of Ti3C2Tx.When applied for catalytic hydrogenation of nitroaromatic compounds,the mechanically robust Pd/Ti3C2Tx■graphene hydrogels exhibit efficient activities,easy separability,and good cyclability.This work is expected to promote the application of Ti3C2Tx-based functional materials for practical applications involving interactions with salt solutions,such as supercapacitors,catalysis,and water purification.展开更多
While the enzymatic reduction of unsaturated compounds usually has high specificity,highly selective reduction processes are hardly realized by heterogeneous industrial catalysts,which is critical for the green produc...While the enzymatic reduction of unsaturated compounds usually has high specificity,highly selective reduction processes are hardly realized by heterogeneous industrial catalysts,which is critical for the green production of many fine chemicals.Here,we report an unexpected discovery of a biomimetic behavior of dicyandiamide(DICY)-modified Pt nanocatalysts for the green hydrogenation of a wide range of nitroaromatics.We demonstrate that the surface modification by DICY not only prevents the direct contact of nitroaromatic reactants with Pt surface but also induces an effective non-contact hydrogenation mechanism mediated by protons and electrons.In such a process,the DICY layer serves as a“semi-permeable membrane”to allow the permeation of H_(2) molecules for being activated into electrons and protons at the Pt-DICY interface.With the generation of separated protons and electrons,the nitro group with strong electrophilic properties can be hydrogenated through the electron transfer followed by the proton transfer,which is facilitated by the hydrogen bonding network formed by protonated DICY.The unique mechanism makes it highly directional toward the hydrogenation of nitro groups without side reactions.Owing to its capability to largely eliminate the waste generation,the developed Pt-DICY catalysts have been successfully applied for the green industrial production of many important aniline intermediates.展开更多
The single cell gel electrophoresis (SCGE) technique was used to detect DNA damage in germ cells of rats, which was induced by five tested nitroaromatic compounds. Mixed cultures of Sertoli and germ cells were prepa...The single cell gel electrophoresis (SCGE) technique was used to detect DNA damage in germ cells of rats, which was induced by five tested nitroaromatic compounds. Mixed cultures of Sertoli and germ cells were prepared from the rats testis and their responses to rn-dinitrobenzene ( m-DNB), 2,4-dinitrotoluene ( 2,4-DNT), 2,6-dinitroto-luene(2,6-DNT), 4-nitrotoluene(4-NT) and 2,4-dinitroaniline(2,4-DNAn) were studied. The results show that all the five chemicals have a reproductive toxicity. Each dose group and the control group were significantly different ( P 〈 0. 01 ). All of them can lead to the damage to DNA in the germ cells of Kunming male rats in the definite range of concentration(m-DNB : 0. 04-25μmol/L; 2,4-DNT, 2,6-DNT and 4-NT: 0. 032-500μmol/L; 2,4-DNAn :0. 8-20μmol/L). When the concentration increases, the damage rate will become higher, which shows an evident logarithm dose-effect relationship.展开更多
基金supported by the National Natural Science Foundation of China (No. 20577041)the New Century Educational Talents Plan of Chinese Education Ministry (No. NCET-05-0525)+1 种基金the Foundation for the Author of National Excellent Doctoral Dissertation of PR China(No.200765)the Program of Provincial Science and Technology of Zhejiang (No. 2006C33050)
文摘To further elucidate interaction of nitroaromatic compounds with mineral surface, the sorption of m-dinitrobenzene (m-DNB) and nitrobenzene to original bentonite in aqueous solution containing different electrolytes (i.e., KCl, NH4Cl, CaCl2 and Tetramethylammonium bromide (TMAB)) was studied. The sorption of m-DNB was greatly enhanced with the presence of KCl and NH4Cl, while little influence was observed with CaCl2 and TMAB, following the order of KCl 〉 NH4Cl 〉〉 TMAB, CaCl2, or DI water. For nitrobenzene, sorption enhancement only occurred at high nitrobenzene concentrations in the presence of KCl, and the solute equilibrium concentration at inflexion point was lowered with increasing KCl concentration. These sorption enhancements were significantly promoted with the increase of electrolyte concentration. The salting-out effect is insufficient to account for the sorption enhancement by original bentonite with increasing KCI or NH4Cl concentration. X-ray diffraction patterns of bentonite suspensions indicated that the sorption enhancement of m-DNB was attributed to the intercalation of K^+ or NH4^+ into bentonite interlayer and then dehydration with m-DNB to form inner-sphere complexes, which caused previously expanded bentonite interlayers to collapse in aqueous suspension, thus further enhanced the interaction of phenyl with siloxane surface. In comparison, the sorption enhancement of NB is attributed to the formation of outer-sphere complexes with K^+ at high solute-loadings (〉 20(0-400 mg/kg). The sorption of m-DNB to initially modified TMA^+-bentonite and K^+-bentonite was almost the same as respective sorption to original bentonite in solution containing TMA^+ and K^+.
基金supported by the Youth Foundation of Education Bureau,Sichuan Province(13ZB0003)
文摘The three-dimensional holographic vector of atomic interaction field(3D-Ho VAIF) is used to characterize the molecular structures of 45 nitroaromatic compounds.Two quantitative structure-toxicity relationship(QSAR) models are built up by stepwise regression(SMR),multiple linear regression(MLR) and partial least-squares regression(PLS).The correlation coefficients(R) of the models are 0.960 and 0.961,respectively.Then the models are evaluated by performing the cross-validation with the leave-one-out(LOO) procedure and the correlation coefficients(RCV) are 0.949 and 0.941,respectively.The results show that the descriptors can successfully describe the structures of organic compounds.The stability and predictability of the model are satisfactory.
基金Supported by the National Natural Science Foundation of China(No.20502022)the Natural Science Foundation of Ningbo (No.2004A610010)
文摘In the present study,geometrical optimization and electrostatic potential calcula-tions have been performed for 22 nitroaromatic compounds at the HF/6-31G level of theory.A number of statistically based parameters have been obtained.Linear relationship between the decomposition enthalpy(taken as a macroscopic property related to explosibility) of nitroaromatic compounds and the structural descriptors have been established by multiple regression method.The result shows that the quantities derived from electrostatic potentialsΣ V sind+,,Vsind- and Vs,max can be well used to express the quantitative structure-decomposition enthalpy relationship of nitroa-romatic compounds,which proves the general applicability of this parameter set to a great extent.Good predictive capabilities have also been demonstrated.
基金supported by the National Natural Science Foundation of China(Grant No.21776161)。
文摘The bimetallic nanoparticles compositing of Ni-rich core and Cu-rich shell(Ni/Cu NPs)were successfully synthesized by a liquid-phase thermal decomposition method.The content of copper and nickel in Ni/Cu NPs was controllable by adjusting the ratio of two metal precursors,copper formate(Cuf)and nickel acetate tetrahydrate(Ni(OAc)_(2)·4H_(2)O).Ni/Cu NPs were further anchored on graphene oxide(GO)to prepare a magnetic composite catalyst,called Ni/Cu-GO.The dispersibility of Ni/Cu NPs in solution was enhanced by GO anchoring to prevent the sintering and aggregation during the reaction process,thereby ensuring the catalytic and cycling performance of the catalyst.The catalytic transfer hydrogenation(CTH)reaction of nitroaromatics was investigated when ammonia borane was used as the hydrogen source.Cu dominated the main catalytic role in the reaction,while Ni played a synergistic role of catalysis and providing magnetic properties for separation.The Ni_(7)/Cu_(3)-GO catalyst exhibited the best catalytic performance with the conversion and yield of 99%and 96%,respectively,when 2-methyl-5-nitrophenol was used as the substrate.The Ni_(7)/Cu_(3)-GO catalyst also exhibited excellent cyclic catalytic performance with the 5-amino-2-methylphenol yield of above 90%after six cycles.In addition,the Ni_(7)/Cu_(3)-GO catalyst could be quickly recycled by magnetic separation.Moreover,the Ni_(7)/Cu_(3)-GO catalyst showed good catalytic performance for halogen-containing nitroaromatics without dehalogenation.
基金Supported by the National Basic Research Program of China(No.2009CB724706)the National Natural Science Foundation of China(No.20876025)
文摘Nitroaromatic compounds were reductively metabolized to the corresponding amine compounds via the intermediate hydroxylamines by liver microsomes from pig,rat,chook,cattle,sheep,paralichthys olivaceus and cyprinoid in varied reactivity.Similar with baker's yeast,the pig,rat and sheep liver microsomes exhibited high reactivity toward 4-nitro-1,2-dicyanbenzen(1a),while the cyprinoid liver microsomes were inefficient.Contrasted to compound 1a,monocyannitrobenzene(2a) was difficult to reduce by pig liver microsomes.In opposition to grape cells,pig liver microsomes exhibited activities toward some aromatic hydroxylamine compounds.
基金Foundationitem :theNationalNaturalScienceFoundationofChina (No .992 90 60 0 )
文摘In general, many pollutants co\|exist in natural aquatic ecosystems. They affect each other and occur different results, such as synergism, addition and antagonism. So the research at mixtoxicity of contaminants to aquatic organism is more important than monotoxicity. In this paper, 50% effectual inhibition concentration 48h \%EC\%\-\{50\} values of 6 kinds of nitroaromatic compounds to the green algae, \%Scenedesmus obliquus,\% were investigated. Mixtoxic experiments, in which any combination of 2,4\|DNT and other 6 kinds of compounds, indicate: (1) synergisms between 2,4\|DNT and 4\|NAn, as well as 4\|NAnis, 1,4\|DNB; (2) antagonisms between 2,4\|DNT and 4\|NT, as well as 4\|NPh, 4\|NCB.
基金Supported by the National Natural Science Foundation of China(No.20502022)
文摘Quantitative structure-property relationships(QSPRs) have been developed to predict the thermal stability for a set of 22 nitroaromatic compounds by means of the theoretical descriptors derived from electrostatic potentials on molecular surface. Several techniques, including partial least squares regression(PLS), least-squares support vector machine(LSSVM) and Gaussian process(GP) have been utilized to establish the relationships between the structural descriptor and the decomposition enthalpy. The nonlinear LSSVM and GP models have proven to own a better predictive ability than the linear PLS method. Moreover, owing to its ability to handle both linear- and nonlinear-hybrid relationship, GP gives a stronger fitting ability and a better predictive power than LSSVM, and therefore could be well applied to developing QSPR models for the thermal stability of nitroaromatic explosives.
基金Project supported by the National Natural Science Foundation of China(21661034)Reserve Talents Project for Youth and Middle-Aged Academic and Technical Leaders of Yunnan Province(202205AC160032)。
文摘Luminescent hydrogels have received considerable attention in the application of sensors.Nitroaro matics are harmful to human health and can be carcinogenic.Some skin allergies and central nervous system injuries may also be attributed to the over exposure to nitroaromatics.Thus,nitroaromatics sensor with fast detection and low detection limit is highly desirable.Herein,novel tough hydrogels were prepared by introducing hydrogen bonds and covalent bonds into the interpenetrating networks of modified chitosan and poly(vinyl alcohol)(PVA) via frozen-thawing induced chemical cross-linking.The synthesized hydrogels exhibit high mechanical strength(0.23 MPa tensile strength at 140% tensile strain,1.0 MPa compressive strength at 80% compressive strain).Strong green emission was realized by energy transfer from the modified chitosan to Tb^(3+)via the so-called "antenna effect." The prepared luminescent hydrogels show an excellent detection effect on nitroaromatic compounds and its detection limit can reach ppm-level.The hydrogels also exhibit good reversibility and a fast "off-on" fluorescence switching process.This work may open up a new way for the development of stable,rapid,and reusable sensors for the detection of harmful nitroaromatics.
基金We thank the National Natural Science Foundation of China for supporting this work(No.22172167)The 1W1B beamline of Beijing Synchrotron Radiation Facility and BL14W1 beamline of Shanghai Synchrotron Radiation Facility are acknowledged for providing the beam time.
文摘Catalysts for chemoselective hydrogenation are of vital importance for the synthesis of various important chemicals and intermediates.Herein we developed a simple method for preparing a highly efficient Ni-MoC_(x)nanocomposite catalyst via temperature-programmed carburization of a polyoxometalate precursor.X-ray diffraction(XRD),scanning transmission electron microscopy(STEM),X-ray photoelectron spectroscopy(XPS),and X-ray absorption spectroscopy(XAS)analyses indicate that the resulting mesoporous nanocomposite catalyst is made up of well-dispersed metallic nickel particles embedded in a MoC_(x)matrix.This catalyst exhibits high activity and selectivity(>99%)in the hydrogenation of various substituted nitroaromatics to corresponding anilines.The high efficiency is attributed to the intimate contact of the constituents favoring electron transfer and hydrogen adsorption.Dihydrogen is physisorbed on the carbide support and dissociates on the nickel particles,as evidenced by Mo K-edge X-ray absorption near-edge structure(XANES)spectra,density functional theory(DFT),and hydrogen-deuterium exchange.The remarkable catalytic performance of the catalyst could be traced back to the synergistic interaction between the Ni particles and the carbide support.In-situ infrared spectroscopy and DFT simulations indicated that the adsorption/activation of the nitro group is favored compared to that of other substituents at the aromatic ring.In recyclability tests,the Ni-MoC_(x)nanocomposite showed no significant loss of catalytic performance in seven consecutive runs,indicating its robust nature.
基金supported by the National Natural Science Foundation of China(No.22175033)Science and Technology Development Plan of Jilin Province(Nos.YDZJ202101ZYTS063,20210508022RQ)Research Foundation of Education Department of Shaanxi Province(No.18JS009)。
文摘Herein,we report a new metal-organic framework with an AIE ligand (H_(4)TCPP=2,3,5,6-tetra-(4-carboxyphenyl)pyrazine) and Mg^(2+) ions,that is,[Mg_(2)(H_(2)O)_(4)TCPP]·DMF·5CH_(3)CN (Mg-TCPP,TCPP=tetra-(4-carboxyphenyl)pyrazine) for detection of nitroaromatic explosives.Due to the coordination effect and restricted intramolecular rotation,Mg-TCPP exhibits bright blue light.As a fluorescent sensor,Mg-TCPP exhibits high selectivity and sensitivity for sensing 2,4,6-trinitrophenol (TNP) by quenching behaviors with the Stern-Volmer quenching constant (K_(SV)) of 3.63×10^(5)L/mol and achieves the low limit of detection of 25.6 ppb,which is beyond most of the previously reported fluorescent materials.Notably,the portable Mg-TCPP films are prepared and it can be used for rapid and sensitive TNP detection in a variety of environments including organic solvent and aqueous solution.Moreover,TNP vapor can be detected within 3 min by naked eye and the film could be regenerated under simple solvent cleaning.
基金the National Key Project of Basic Research(Grant No.2003CB415002)National Natural Science Foundation of China(Grant No.20177008)+2 种基金EU International Scientific Cooperative Project(Grant No.ICA4-CT-2001-10039)863 High Tech.Project of China(Grant No.2001AA640601-4)Top 6 Talents Training Program of Jiangsu Province and Innovative Young Talents Program.
文摘Nitroaromatics are typical toxic organic pollutants and are ubiquitous in environment with diverse structures. They are widely used in many industries and formed during many natural and anthropogenic processes. Most of these pollutants are potentially carcinogenic and the as-sessment and prediction of the mutagenicity of nitroaromatics are of great interest. In this paper the structure-mutagenicity relationships of 219 nitroaromatics are investigated by molecular or-bital theory based classic structure-activity relationships and comparative molecular field analysis (CoMFA). A comparison is undertaken in respect of the interpretation of mechanism and predic-tive ability for these two categories of QSAR approaches and highly predictive QSAR models have been developed.
文摘Heterogeneous iridium catalysts were prepared and applied for the reductive amination of aldehydes and ketones with nitroaromatics and amines using H2. The iridium catalysts were prepared by pyrolysis of ionic liquid 1-methyl-3-cyanomethylimidazoulium chloride ([MCNI]C1) with iridium chloride (IrC13) in activated carbons. Iridium particles were well dispersed and stable in the N-doped carbon materials from [MCNI]C1 with activated carbon. The Ir@NC(600-2h) catalyst was found to be highly active and selective for the reductive amination of aldehydes and ketones using H2 and a variety of nitrobenzenes and amines were selectively converted into the corresponding secondary and tertiary amines. The Ir@NC(600-2h) catalyst can be reusable several times without evident deactivation.
文摘The DFT-B3LYP method, with the basis set 6-311G, was employed to calculate the molecular geometries and electronic structures of 31 nitroaromatics. EHOMO, ELUMO, QC, QN. QNO2 and μ were selected as quantum chemical descriptors. The acute toxicity (-lg LC50) of these compounds to the fathead minnow along with the six descriptors was used to establish the quantitative structure-activity relationships (QSARs), Through stepwise multiple linear regression analysis, a model was established as follows: -lg LC50=9.524-39.527ELUMO+16.859EHOMO+15.130QNO2+4.166QC (n=28, R=0.912, SE=0.361, F=28.468). The model was applied to predict and elucidate the toxicity of nitroaromatics successfully. Furthermore, a metabolic route of nitroaromatics in fathead minnow was proposed.
基金supported by the National Natural Science Foundation of China(NSFC, No. 21771191)the Shandong Natural Science Fund (No. ZR2017QB012)+2 种基金the Applied Basic Research Projects of Qingdao (No.16-5-1-95-jch)the Fundamental Research Funds for the Central Universities (Nos.16CX05015A,18CX06003A, YCX2018071)the Foundation of State Key Laboratory of Structural Chemistry (No. 20160006)
文摘Three cadmium(II) metal-organic frameworks(MOFs) based on tetracarboxylate ligands, namely[Cd_2(TTTA)(DMF)_3]·2 DMF(1),[Cd_2(TB)(H_2O)_4]·3DMF·H_2O(2)and [Cd(TEB)_(0.5)].2 DMF.4 H_2O(3) have been designed and synthesized. Complex 1 is a 2-dimensional(2 D) 3,4-connected network with 3,4 L13 topology, complex 2 features a 3-dimensional(3D) 3,4-connected tfa topology with a 2-fold interpenetrating structure and complex 3 has a 3D 4-connected dia topology with a 4-fold interpenetrating structure. Interestingly, 2 exhibits permanent pores and selective adsorption of CO_2 over CH_4. In addition, 2 shows fluorescence sensing of Fe^(3+) ion and rapid detection of nitroaromatic compounds(NACs) through fluorescence quenching.
文摘Herein we describe the development of a homogeneous assay for the detection of 4-nitroaniline(4-NA)and 2,4-dinitroaniline(2,4-diNA).Thisassay relies on fluorescent molecularly imprinted nanoparticles(nano MIPs)which,upon interaction with the target analytes,generate areduction in fluorescence emission intensity(quenching).This is due to a resp on sive fluorescent monomer(N-2-propenyl-(5-dimethylamino)-1-naphthalene sulphonamide)employed in the manufacture of the nanoMIPs which,by virtue of the imprinting process,is capable of selectiveinteraction with the target an alyte,thus giving rise to a quenching effect.Selectivity experiments showed excellent recognition propertiestoward the target molecule.Under optimal conditions,the fluorescence intensity of these nano MIPs decreased as the concentration of theimprinted analyte increased from 10 nM to 2.71 pM.A linear relation between the negative logarithm of 4-NA or 2,4-diNA concentrations and the fluorescence intensity for both nanosystems was found(R^2=0.991 and R^2=0.9895),with excellent sensitivity(limit of detection(LOD)=7 and 6 nM,respectively).Furthermore,both nanosystems have been successfully applied for detection of 4-NA or 2,4-diNA in tap water,withrecoveries between 90%to 100.6%and 92%to 100.3%,respectively.Thanks to the versatility of the imprinting process,this nanosystemholds the potential for further development of several optical sensors for many other compounds.
基金supported by the National Natural Science Foundation of China(NSFC, No. 21771191)the Taishan Scholar Foundation(No. ts201511019)+1 种基金the Shandong Natural Science Fund (No.ZR2017QB012)the Fundamental Research Funds for the Central Universities(Nos.16CX05015A,18CX06003A,YCX2018071)
文摘Two Co(II)-MOFs with different structures were successfully synthesized under the premise of designing two ligands containing alkynyl functional groups. Complexes 1 ([Co(TEPA)(TPT)2/3]·2DMF·H2O) and 2 ([Co(EPA)(TPT)]·1.5DMF·1.5H2O) show excellent luminescence properties. Meanwhile, as fluorescent sensors, complexes 1 and 2 exhibit selectivity and sensitivity for Fe3+ with the Ksv of 1.520 ×104 L/mol and 3.543 ×104 L/mol, which can rapidly detect nitroaromatic compounds in methanol and ethanol, especially for 2,4-NPH through fluorescence quenching with high quenching efficiency. In particular, the Ksv value of complexes 1 and 2 towards 2,4-NPH can reach up to 1.627 ×105 L/mol and 9.600 ×104 L/mol, demonstrating that complexes 1 and 2 are good candidates for the identification and detection of Fe3+and nitroaromatic compounds.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 29837180 and 29907001) also by the National Natural Science Foundation of China (Grant No. 98028407).
文摘The 3-D relationships between the structures of 25 nitroaromatic compounds and their toxicities have been investigated using the comparative molecular field analysis (CoMFA) method, and a 3-D QSAR model with considerable prediction ability is obtained. In comparison with traditional 2-D techniques, CoMFA helps to give a better interpretation of toxic mechanism of tested compounds.
基金support from the National Natural Science Foundation of China(Nos.51802040,51977071 and 21802020)Key Laboratory of Coal to Ethylene Glycol and Its Related Technology,Chinese Academy of Sciences(No.201901)+1 种基金Natural Science Foundation of Hunan Prvoince(No.2017JJ2040)the Fundamental Research Funds for the Central Universities。
文摘Ti3C2Tx has been emerging as an attractive platform to prepare composite catalysts,and their assembly into integrated catalytic mate rials repre sents a key step forward toward practical applications.Howeve r,the swelling behavior of Ti3C2Tx leads to significant structure change,which challenges the stability of Ti3C2Tx-based integrated functional materials for catalytic applications.Here we report a facile synthesis of Pd/Ti3C2Tx■graphene hydrogels in which Pd/Ti3C2Tx are spatially encapsulated in the 3 D porous graphene framework.The porous interconnected structure not only affords efficient mass transfer and desirable functional accessibility to catalytic active sites,but also effectively buffers the swelling behavior of Ti3C2Tx.When applied for catalytic hydrogenation of nitroaromatic compounds,the mechanically robust Pd/Ti3C2Tx■graphene hydrogels exhibit efficient activities,easy separability,and good cyclability.This work is expected to promote the application of Ti3C2Tx-based functional materials for practical applications involving interactions with salt solutions,such as supercapacitors,catalysis,and water purification.
基金supported by the National Key Research and Development Program of China(2017YFA0207302)the National Nature Science Foundation of China(21890752,21731005,22072116,92045303)+1 种基金support from the Tencent Foundation through the XPLORER PRIZEthe XAFS Station(BL14W1)of the Shanghai Synchrotron Radiation Facility(SSRF)。
文摘While the enzymatic reduction of unsaturated compounds usually has high specificity,highly selective reduction processes are hardly realized by heterogeneous industrial catalysts,which is critical for the green production of many fine chemicals.Here,we report an unexpected discovery of a biomimetic behavior of dicyandiamide(DICY)-modified Pt nanocatalysts for the green hydrogenation of a wide range of nitroaromatics.We demonstrate that the surface modification by DICY not only prevents the direct contact of nitroaromatic reactants with Pt surface but also induces an effective non-contact hydrogenation mechanism mediated by protons and electrons.In such a process,the DICY layer serves as a“semi-permeable membrane”to allow the permeation of H_(2) molecules for being activated into electrons and protons at the Pt-DICY interface.With the generation of separated protons and electrons,the nitro group with strong electrophilic properties can be hydrogenated through the electron transfer followed by the proton transfer,which is facilitated by the hydrogen bonding network formed by protonated DICY.The unique mechanism makes it highly directional toward the hydrogenation of nitro groups without side reactions.Owing to its capability to largely eliminate the waste generation,the developed Pt-DICY catalysts have been successfully applied for the green industrial production of many important aniline intermediates.
文摘The single cell gel electrophoresis (SCGE) technique was used to detect DNA damage in germ cells of rats, which was induced by five tested nitroaromatic compounds. Mixed cultures of Sertoli and germ cells were prepared from the rats testis and their responses to rn-dinitrobenzene ( m-DNB), 2,4-dinitrotoluene ( 2,4-DNT), 2,6-dinitroto-luene(2,6-DNT), 4-nitrotoluene(4-NT) and 2,4-dinitroaniline(2,4-DNAn) were studied. The results show that all the five chemicals have a reproductive toxicity. Each dose group and the control group were significantly different ( P 〈 0. 01 ). All of them can lead to the damage to DNA in the germ cells of Kunming male rats in the definite range of concentration(m-DNB : 0. 04-25μmol/L; 2,4-DNT, 2,6-DNT and 4-NT: 0. 032-500μmol/L; 2,4-DNAn :0. 8-20μmol/L). When the concentration increases, the damage rate will become higher, which shows an evident logarithm dose-effect relationship.