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2009 Volume 26 Issue 11
2009, 26(11): 1253-1258
Abstract:
Three novel 1,3-benzyldiacyl hydrazone derivatives(4a～4c) were designed and synthesized.The binding properties of the receptor with anions such as F-,Cl-,Br-,I-,CH3COO-,HSO4-,H2PO4- and ClO4- in DMSO were investigated by UV-Vis and 1H NMR.As a result,receptor 4a(1,3-benzyldi(4-nitropheyl-2-furfuraldehyde) methacylhydrazone) can recognize anions through hydrogen bonding in DMSO solutions.A clear color change was observed from yellow to dark yellow and pale red upon addition of F-and CH3COO-.1H NMR titration and solvation effect confirm hydrogen bonding interaction between the receptor and the anions.Job curve indicates that a 1:1 stoichiometry complex is formed between the receptor and the two kinds of anions.Based on the above results,the recognition binding mode was discussed.The molecular recognition ability was discussed in terms of the size and shape-fit as well as the recognition model between host and guest molecules.
Three novel 1,3-benzyldiacyl hydrazone derivatives(4a～4c) were designed and synthesized.The binding properties of the receptor with anions such as F-,Cl-,Br-,I-,CH3COO-,HSO4-,H2PO4- and ClO4- in DMSO were investigated by UV-Vis and 1H NMR.As a result,receptor 4a(1,3-benzyldi(4-nitropheyl-2-furfuraldehyde) methacylhydrazone) can recognize anions through hydrogen bonding in DMSO solutions.A clear color change was observed from yellow to dark yellow and pale red upon addition of F-and CH3COO-.1H NMR titration and solvation effect confirm hydrogen bonding interaction between the receptor and the anions.Job curve indicates that a 1:1 stoichiometry complex is formed between the receptor and the two kinds of anions.Based on the above results,the recognition binding mode was discussed.The molecular recognition ability was discussed in terms of the size and shape-fit as well as the recognition model between host and guest molecules.
2009, 26(11): 1259-1263
Abstract:
Amidoxime chelating fiber containing Fe(Ⅲ) was prepared from the reaction of partially amido-ximated PAN fiber with Fe3+.The studies of its adsorptive behavior for vat brown dye were performed in aqueous media.Results from the investigation on its adsorptive conditions,adsorption rules and adsorption kinetics show that the optimal adsorption parameters are pH:11.5～12.5,t=60 ℃(temperature) and time=60 min(time).Its adsorptive behavior for vat brown dye fits well with Langmuir and Freundlich isotherm equation.Furthermore,the relationship between adsorption time and sample concentration was investigated by employing various initial concentrations,from which the corresponding reaction order and rate constant were determined by differential method.Based on the Arrhenius equation,the activation energy(Ea) was calculated to be 11.55 kJ/mol from rate constants at different temperatures.The overall analysis demonstrates that the adsorptive behavior of the present amidoxime chelating fiber containing Fe(Ⅲ) for vat brown BR dye chara-cterizes first-order reaction with c=c0e-kt and k=32.01e-Ea/RT.
Amidoxime chelating fiber containing Fe(Ⅲ) was prepared from the reaction of partially amido-ximated PAN fiber with Fe3+.The studies of its adsorptive behavior for vat brown dye were performed in aqueous media.Results from the investigation on its adsorptive conditions,adsorption rules and adsorption kinetics show that the optimal adsorption parameters are pH:11.5～12.5,t=60 ℃(temperature) and time=60 min(time).Its adsorptive behavior for vat brown dye fits well with Langmuir and Freundlich isotherm equation.Furthermore,the relationship between adsorption time and sample concentration was investigated by employing various initial concentrations,from which the corresponding reaction order and rate constant were determined by differential method.Based on the Arrhenius equation,the activation energy(Ea) was calculated to be 11.55 kJ/mol from rate constants at different temperatures.The overall analysis demonstrates that the adsorptive behavior of the present amidoxime chelating fiber containing Fe(Ⅲ) for vat brown BR dye chara-cterizes first-order reaction with c=c0e-kt and k=32.01e-Ea/RT.
2009, 26(11): 1264-1268
Abstract:
Polyaniline/CoC2O4 nanocomposite with both electrical and magnetic conductivities was synthesized by means of in-situ growth of polyaniline under different conditions on the surface of nano-cobalt oxalate,which was obtained by low heating solid state reaction.The influences of different reaction conditions including reactants' ratio,mixing methods,type and quantity of surfactants on the morphology and structure and their electromagnetic properties of resulting composites were investigated.The products were characterized by TEM,XRD,and TG analysis techniques.The results indicate that the morphology and structure and their microwave absorbing performance of the as-prepared nanocomposites can be effectively tuned by changing the in-situ complex conditions.The optimal experimental results were as follows:polyaniline/CoC2O4 nanocomposite obtained under ultrasonication showed a maximum reflection loss of-28.8 dB at 8.6 GHz with a bandwidth of 3.2 GHz above-10 dB loss.
Polyaniline/CoC2O4 nanocomposite with both electrical and magnetic conductivities was synthesized by means of in-situ growth of polyaniline under different conditions on the surface of nano-cobalt oxalate,which was obtained by low heating solid state reaction.The influences of different reaction conditions including reactants' ratio,mixing methods,type and quantity of surfactants on the morphology and structure and their electromagnetic properties of resulting composites were investigated.The products were characterized by TEM,XRD,and TG analysis techniques.The results indicate that the morphology and structure and their microwave absorbing performance of the as-prepared nanocomposites can be effectively tuned by changing the in-situ complex conditions.The optimal experimental results were as follows:polyaniline/CoC2O4 nanocomposite obtained under ultrasonication showed a maximum reflection loss of-28.8 dB at 8.6 GHz with a bandwidth of 3.2 GHz above-10 dB loss.
2009, 26(11): 1269-1272
Abstract:
Perylene derivatives PeryBr2,DD-PeryBr2 and DD-PeryBp2 were synthesized from perylene-3,4,9,10-tetracarboxylic acid bisanhydride and characterized by UV-Vis,FT-IR,1H NMR,MS,TGA and fluore-scence spectroscopy measurements.The result shows that DD-PeryBp2 is highly soluble in conventional solvents such as toluene,chloroform and THF.The UV-Vis maximal absorption and fluorescence spectroscopy maximal emission of DD-PeryBp2 are at 548 nm and 576 nm,respectively.TG measurements show that perylene diimides possess good thermal stability and the temperature at which 5% mass loss is observed in nitrogen is 433 ℃.
Perylene derivatives PeryBr2,DD-PeryBr2 and DD-PeryBp2 were synthesized from perylene-3,4,9,10-tetracarboxylic acid bisanhydride and characterized by UV-Vis,FT-IR,1H NMR,MS,TGA and fluore-scence spectroscopy measurements.The result shows that DD-PeryBp2 is highly soluble in conventional solvents such as toluene,chloroform and THF.The UV-Vis maximal absorption and fluorescence spectroscopy maximal emission of DD-PeryBp2 are at 548 nm and 576 nm,respectively.TG measurements show that perylene diimides possess good thermal stability and the temperature at which 5% mass loss is observed in nitrogen is 433 ℃.
2009, 26(11): 1273-1276
Abstract:
Two novel poly(ether ether ketone)s(PEEK) containing imide moiety with inherent viscosities of 0.98 dL/g and 0.61 dL/g were respectively prepared by low temperature solution polycondensation from 1,4-diphenylbenzene(DPB) with N,N'-(4,4'-diphenylmethane) bistrimelletimide diacid chloride(DCDI-M) or N,N'-(4,4'-diphenylsulfone) bistrimelletimide diacid chloride(DCDI-S).The polymers were characterized by FT-IR,1H NMR,DSC,TGA and WAXD.The results show that the polymers are amorphous.The glass transition temperatures(Tg) are 236 ℃ and 263 ℃,respectively.The onset temperatures taken at a 5% mass loss of each of the polymers in nitrogen atmosphere are all over 512 ℃.The polymers are soluble in common organic solvents such as N,N-dimethylacetamide(DMAc),N-methylpyrrolidone(NMP),cresol and chloroform at room temperature.
Two novel poly(ether ether ketone)s(PEEK) containing imide moiety with inherent viscosities of 0.98 dL/g and 0.61 dL/g were respectively prepared by low temperature solution polycondensation from 1,4-diphenylbenzene(DPB) with N,N'-(4,4'-diphenylmethane) bistrimelletimide diacid chloride(DCDI-M) or N,N'-(4,4'-diphenylsulfone) bistrimelletimide diacid chloride(DCDI-S).The polymers were characterized by FT-IR,1H NMR,DSC,TGA and WAXD.The results show that the polymers are amorphous.The glass transition temperatures(Tg) are 236 ℃ and 263 ℃,respectively.The onset temperatures taken at a 5% mass loss of each of the polymers in nitrogen atmosphere are all over 512 ℃.The polymers are soluble in common organic solvents such as N,N-dimethylacetamide(DMAc),N-methylpyrrolidone(NMP),cresol and chloroform at room temperature.
2009, 26(11): 1277-1281
Abstract:
2,8-Bis[2'-(4″-pyridyl)ethenyl]-5-ethylcarbazole and 2,8-bis[2'-(2″-pyridyl)ethenyl]-5-ethylcarbazole were synthesized from N-ethyl carbazole at room temperature via a solid-state reaction.Their structures were characterized by 1H NMR,IR and MS.Two-photon absorption cross-sections were obtained by Z-scan technique.The femtosecond single pulse laser(820 nm) as writing laser was applied to the storage medium for two-photon photobleaching,indicating that they would be three-dimensional optical storage materials.
2,8-Bis[2'-(4″-pyridyl)ethenyl]-5-ethylcarbazole and 2,8-bis[2'-(2″-pyridyl)ethenyl]-5-ethylcarbazole were synthesized from N-ethyl carbazole at room temperature via a solid-state reaction.Their structures were characterized by 1H NMR,IR and MS.Two-photon absorption cross-sections were obtained by Z-scan technique.The femtosecond single pulse laser(820 nm) as writing laser was applied to the storage medium for two-photon photobleaching,indicating that they would be three-dimensional optical storage materials.
2009, 26(11): 1282-1286
Abstract:
A series of N,N'-bis(2-hydroxy benzyl) substituted imidazolidine derivatives(3a～3h) were designd and synthesized by means of combining segments o-hydroxy phenyl and imidazolidine compounds,according to the reinforcement of biological activities.The N,N'-bis-o-hydroxy benzyl diaminoethane(2) was synthesized using salicylaldehyde and 1,2-diaminoethane,through condensation reaction and then reduction by NaBH4,and further cyclization with aromatic aldehydes.The structures of all the compounds were confirmed by 1H NMR,IR,mass spectra and elemental analysis.The results show that the reaction of salicylaldehyde with 1,2-diaminoethane only formed the symmetric Schiff base(1),the condensation of aromatic aldehyde with compound 2 was noticeably different for different substituents: o-,p-substituted electron-withdrawing groups can activate aromatic aldehyde and result in a higher yield of ring closing reaction,but o-,p-substitute electron-donating groups have opposite effects.The result of preliminary bioassay shows that the target compounds had obvious specificity to different bacteria at 0.1%(mass concentration),and had an inhibitory rate of 100% on Monilia albican and Escherichia coli.
A series of N,N'-bis(2-hydroxy benzyl) substituted imidazolidine derivatives(3a～3h) were designd and synthesized by means of combining segments o-hydroxy phenyl and imidazolidine compounds,according to the reinforcement of biological activities.The N,N'-bis-o-hydroxy benzyl diaminoethane(2) was synthesized using salicylaldehyde and 1,2-diaminoethane,through condensation reaction and then reduction by NaBH4,and further cyclization with aromatic aldehydes.The structures of all the compounds were confirmed by 1H NMR,IR,mass spectra and elemental analysis.The results show that the reaction of salicylaldehyde with 1,2-diaminoethane only formed the symmetric Schiff base(1),the condensation of aromatic aldehyde with compound 2 was noticeably different for different substituents: o-,p-substituted electron-withdrawing groups can activate aromatic aldehyde and result in a higher yield of ring closing reaction,but o-,p-substitute electron-donating groups have opposite effects.The result of preliminary bioassay shows that the target compounds had obvious specificity to different bacteria at 0.1%(mass concentration),and had an inhibitory rate of 100% on Monilia albican and Escherichia coli.
2009, 26(11): 1287-1291
Abstract:
Chitosan-g-N-carboxymethyl-2-sulfo-4,5-2H imidazolinone(CSIDZ) with different grafting ratio polymers were synthesized with 2-bromoacetic acid,chitosan,2-sulfo imidazolinone as raw materials.Their physical and chemical characteristics were studied.Adsorptions of synthesized polymers for metal ions,such as,Cd2+,CrO42-,Fe3+,Cu2+,Pb2+ were determined with EDTA complexometric titration.The antibacterial activity of the grafted polymer was examined against a series of test microorganisms by quantitative suspension method;corrosion inhibition efficiency of the synthesized polymer in 1 mol/L HCl solutions for N80 steel panel was measured by mass-loss method.Results from the experiments indicate that the partially grafted CSIDZ made the complexing action of partially grafted CSIDZ to most tested metal ions higher thermal stability than small molecule-CSIDZ,the grafted polymer bears a relatively strong antibacterial activity,its MIC(minimal inhibited concentration) is 5.10 g/L and it has a higher thermal stability than small molecule inhibitor CSIDZ.Its inhibition efficiency still amounts to 71.1% when temperature reaches to 90 ℃,and the amount used is only 1/2 that of CSIDZ.
Chitosan-g-N-carboxymethyl-2-sulfo-4,5-2H imidazolinone(CSIDZ) with different grafting ratio polymers were synthesized with 2-bromoacetic acid,chitosan,2-sulfo imidazolinone as raw materials.Their physical and chemical characteristics were studied.Adsorptions of synthesized polymers for metal ions,such as,Cd2+,CrO42-,Fe3+,Cu2+,Pb2+ were determined with EDTA complexometric titration.The antibacterial activity of the grafted polymer was examined against a series of test microorganisms by quantitative suspension method;corrosion inhibition efficiency of the synthesized polymer in 1 mol/L HCl solutions for N80 steel panel was measured by mass-loss method.Results from the experiments indicate that the partially grafted CSIDZ made the complexing action of partially grafted CSIDZ to most tested metal ions higher thermal stability than small molecule-CSIDZ,the grafted polymer bears a relatively strong antibacterial activity,its MIC(minimal inhibited concentration) is 5.10 g/L and it has a higher thermal stability than small molecule inhibitor CSIDZ.Its inhibition efficiency still amounts to 71.1% when temperature reaches to 90 ℃,and the amount used is only 1/2 that of CSIDZ.
2009, 26(11): 1292-1296
Abstract:
Bisphenol AF was prepared from HFA·3H2O and aniline under atmospheric pressure in 4 steps:condensation,diazotization,hydrolysis and Friedel-Crafts alkylation.Firstly,2-(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropan-2-ol(Ⅰ) was obtained in a yield of 96.3% from HFA·3H2O and aniline under optimal conditions with Nb2O5 as catalyst at an n(HFA·3H2O):n(aniline):n(Nb2O5) ratio of 2:1:0.1 under reflux for 6 h.Then 2-(4-hydroxy phenyl)-1,1,1,3,3,3-hexafluoropropan-2-ol(Ⅱ) was synthesized from compound(Ⅰ) via diazotization,hydrolysis.The optimum reaction conditions were as follows:during diazotization,n(Ⅰ):n(H2SO4):n(NaNO2) was 1:4.1:1.1,the mass fraction of H2SO4 was 14.7% and reaction temperature-2～2 ℃;during hydrolysis,the mass fraction of H2SO4 was 50%,n(H2SO4):n(Ⅰ) is 11:1.Under these conditions,the yield was 92.7%.Subsequently,in the presence of methanesulfonic acid,the Friedel-Crafts alkylation of compound Ⅱ with phenol yielded target compound bisphenol AF(Ⅲ)in a yield of 72.4%.The total yield was 64.6% based on aniline.
Bisphenol AF was prepared from HFA·3H2O and aniline under atmospheric pressure in 4 steps:condensation,diazotization,hydrolysis and Friedel-Crafts alkylation.Firstly,2-(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropan-2-ol(Ⅰ) was obtained in a yield of 96.3% from HFA·3H2O and aniline under optimal conditions with Nb2O5 as catalyst at an n(HFA·3H2O):n(aniline):n(Nb2O5) ratio of 2:1:0.1 under reflux for 6 h.Then 2-(4-hydroxy phenyl)-1,1,1,3,3,3-hexafluoropropan-2-ol(Ⅱ) was synthesized from compound(Ⅰ) via diazotization,hydrolysis.The optimum reaction conditions were as follows:during diazotization,n(Ⅰ):n(H2SO4):n(NaNO2) was 1:4.1:1.1,the mass fraction of H2SO4 was 14.7% and reaction temperature-2～2 ℃;during hydrolysis,the mass fraction of H2SO4 was 50%,n(H2SO4):n(Ⅰ) is 11:1.Under these conditions,the yield was 92.7%.Subsequently,in the presence of methanesulfonic acid,the Friedel-Crafts alkylation of compound Ⅱ with phenol yielded target compound bisphenol AF(Ⅲ)in a yield of 72.4%.The total yield was 64.6% based on aniline.
2009, 26(11): 1297-1300
Abstract:
With β-ionone as the starting material,the plant hormon abscisic acid,3-methyl-5-(1-hydroxy-4-oxo-2,6,6-trimethyl-2-cyclohexene-1-yl)-2,4-pentadienoicacid,was synthesized via epoxidation by oxidant metachloroperbenzoic acid instead of chromium oxidant,ring-opening,allylic oxidation with oxygen catalyzed by Co(acac)2,Wittig rection and basic hydrolysis in a total yield of 39%.The structures were characterized by IR,1H NMR,MS and elemental analysis.
With β-ionone as the starting material,the plant hormon abscisic acid,3-methyl-5-(1-hydroxy-4-oxo-2,6,6-trimethyl-2-cyclohexene-1-yl)-2,4-pentadienoicacid,was synthesized via epoxidation by oxidant metachloroperbenzoic acid instead of chromium oxidant,ring-opening,allylic oxidation with oxygen catalyzed by Co(acac)2,Wittig rection and basic hydrolysis in a total yield of 39%.The structures were characterized by IR,1H NMR,MS and elemental analysis.
2009, 26(11): 1301-1304
Abstract:
A-ring synthon 5 was synthesized from 1,3-cyclohexanedione via methylation and carbonyl protection.C-ring synthon 9 was synthesized from 1-methoxy-2-methylbenzene by means of bromination,the addition of ethylene epoxide and further bromination.Compound 5 reacted with Grignard reagent of 9 followed by cyclozation to afford target molecule 11.All intermediates and target product were confirmed by IR,1H NMR and HRMS.In conclusion,a simple synthetic route has been developed and the target molecule has been successfully synthesized.
A-ring synthon 5 was synthesized from 1,3-cyclohexanedione via methylation and carbonyl protection.C-ring synthon 9 was synthesized from 1-methoxy-2-methylbenzene by means of bromination,the addition of ethylene epoxide and further bromination.Compound 5 reacted with Grignard reagent of 9 followed by cyclozation to afford target molecule 11.All intermediates and target product were confirmed by IR,1H NMR and HRMS.In conclusion,a simple synthetic route has been developed and the target molecule has been successfully synthesized.
2009, 26(11): 1305-1309
Abstract:
A practical catalytic method to oxidize α-ionone with molecular oxygen under normal pressure and temperature in the presence of catalyst N-hydroxyphthalimide(NHPI) combined with Co(acac)2 was developed,and the probable catalytic mechanism was proposed.Influences of the reaction conditions on the conversion of α-ionone and the selectivity of the major product(5-oxo-α-ionone) were investigated,the optimal technical parameters for 5-oxo-α-ionone were optimized.The results show that the primary products were 5-oxo-α-ionone,epoxy-α-ionone,as well as rearrangement products 4-oxo-β-ionone and epoxy-β-ionone,which were characterized by infrared spectroscopy,1H nuclear magnetic resonance spectroscopy,mass spectrometry and elemental analysis.The yield of 5-oxo-α-ionone and the conversion of α-ionone were 53.4% and 95.0%,respectively,under the conditions of 25% NHPI,1.0% Co(acac)2(in molar ratio),O2 pressure of 1.0 MPa,the reaction temperature at 70 ℃,and reaction time of 10 h,the procedure shows a good reprodu-cibility in the parallel experiments.
A practical catalytic method to oxidize α-ionone with molecular oxygen under normal pressure and temperature in the presence of catalyst N-hydroxyphthalimide(NHPI) combined with Co(acac)2 was developed,and the probable catalytic mechanism was proposed.Influences of the reaction conditions on the conversion of α-ionone and the selectivity of the major product(5-oxo-α-ionone) were investigated,the optimal technical parameters for 5-oxo-α-ionone were optimized.The results show that the primary products were 5-oxo-α-ionone,epoxy-α-ionone,as well as rearrangement products 4-oxo-β-ionone and epoxy-β-ionone,which were characterized by infrared spectroscopy,1H nuclear magnetic resonance spectroscopy,mass spectrometry and elemental analysis.The yield of 5-oxo-α-ionone and the conversion of α-ionone were 53.4% and 95.0%,respectively,under the conditions of 25% NHPI,1.0% Co(acac)2(in molar ratio),O2 pressure of 1.0 MPa,the reaction temperature at 70 ℃,and reaction time of 10 h,the procedure shows a good reprodu-cibility in the parallel experiments.
2009, 26(11): 1310-1314
Abstract:
In order to understand the chemical mechanism of the increase in the output of plants by rare earth fertilizers,the interaction between Eu3+ and catalase(CAT) was investigated with the UV-Vis absorption spectroscopy,synchronous fluorescent spectroscopy and electrochemical method.The results indicate that Eu3+ mainly interacts with the carboxyl oxygen in the amino acid residues of the peptide chain of CAT because rare earth ions are easy to be coordinated with O,causing the change in the peptide conformation and in turn the change in the structure of the heme group of CAT.When the concentration of Eu3+ is low,the interaction between Eu3+ and CAT induce the non-planarity of the heme group of CAT and then increase the exposure extent of the active center,Fe(Ⅲ),leading to the increase in the electrochemical activity and the bioelectrocatalytic activity of CAT for the H22O2 reduction.However,when the concentration of Eu3+ is high,Eu3+ would decrease the non-planarity of the heme group and the exposure extent of Fe(Ⅲ),leading to the decrease in the electrochemical and the bioelectrocatalytic activities of CAT.These results illustrate that the effects of the different concentrations of Eu3+ on the bioactivity of CAT are different.Therefore,selecting the suitable concentration of Eu3+ can promote the growth of plants.
In order to understand the chemical mechanism of the increase in the output of plants by rare earth fertilizers,the interaction between Eu3+ and catalase(CAT) was investigated with the UV-Vis absorption spectroscopy,synchronous fluorescent spectroscopy and electrochemical method.The results indicate that Eu3+ mainly interacts with the carboxyl oxygen in the amino acid residues of the peptide chain of CAT because rare earth ions are easy to be coordinated with O,causing the change in the peptide conformation and in turn the change in the structure of the heme group of CAT.When the concentration of Eu3+ is low,the interaction between Eu3+ and CAT induce the non-planarity of the heme group of CAT and then increase the exposure extent of the active center,Fe(Ⅲ),leading to the increase in the electrochemical activity and the bioelectrocatalytic activity of CAT for the H22O2 reduction.However,when the concentration of Eu3+ is high,Eu3+ would decrease the non-planarity of the heme group and the exposure extent of Fe(Ⅲ),leading to the decrease in the electrochemical and the bioelectrocatalytic activities of CAT.These results illustrate that the effects of the different concentrations of Eu3+ on the bioactivity of CAT are different.Therefore,selecting the suitable concentration of Eu3+ can promote the growth of plants.
2009, 26(11): 1315-1319
Abstract:
A zinc manganese oxide nano-catalyst was synthesized by a co-precipitation method.X-ray diffraction(XRD) and transmission electron microscopy(TEM) results indicate that the sample can be indexed to tetragonal ZnMn2O4 and the particle size ranges from 20 to 50 nm.The obtained ZnMn2O4 nanoparticles were used as a catalyst for the esterification reaction between acetic acid and n-butanol.The experimental results show that ZnMn2O4 nanoparticles had a high catalytic activity on the synthesis of n-butyl acetate.The influential factors including catalyst calcination temperature,acid-to-alcohol molar ratio,dosage of the catalyst and reaction time on the yield of n-butyl acetate were also investigated,and the maximal esterification rate of up to 92.53% was achieved under the following conditions: catalyst calcination temperature=300 ℃,n(acid):n(alcohol)=1.8:1,the dosage of the ZnMn2O4 catalyst is 0.3%(in total mass of reactants),reaction time is 4 h and esterification reaction temperature is 120 ℃.
A zinc manganese oxide nano-catalyst was synthesized by a co-precipitation method.X-ray diffraction(XRD) and transmission electron microscopy(TEM) results indicate that the sample can be indexed to tetragonal ZnMn2O4 and the particle size ranges from 20 to 50 nm.The obtained ZnMn2O4 nanoparticles were used as a catalyst for the esterification reaction between acetic acid and n-butanol.The experimental results show that ZnMn2O4 nanoparticles had a high catalytic activity on the synthesis of n-butyl acetate.The influential factors including catalyst calcination temperature,acid-to-alcohol molar ratio,dosage of the catalyst and reaction time on the yield of n-butyl acetate were also investigated,and the maximal esterification rate of up to 92.53% was achieved under the following conditions: catalyst calcination temperature=300 ℃,n(acid):n(alcohol)=1.8:1,the dosage of the ZnMn2O4 catalyst is 0.3%(in total mass of reactants),reaction time is 4 h and esterification reaction temperature is 120 ℃.
2009, 26(11): 1320-1323
Abstract:
A novel electrolyte CaZr0.1Ti0.9O3 for solid oxide fuel cell(SOFC) was synthesized by a newly sol-combustion method.The structure and conduction properties of the sample were systematically investigated via XRD and electrochemical methods.The results show that CaZr0.1Ti0.9O3 powders were successfully prepared by the sol-combustion technique.The powder shows a high sinterability,and a relative density of 95% at a sintering temperature of 1 400 ℃.Electrochemistry measurements show that the CaZr0.1Ti0.9O3 ceramics has a relatively high oxide ionic conductivity(σ800 ℃=2.24×10-3 S/cm),low electrical activation energy(Ea=0.89 eV) in the low-temperature range.
A novel electrolyte CaZr0.1Ti0.9O3 for solid oxide fuel cell(SOFC) was synthesized by a newly sol-combustion method.The structure and conduction properties of the sample were systematically investigated via XRD and electrochemical methods.The results show that CaZr0.1Ti0.9O3 powders were successfully prepared by the sol-combustion technique.The powder shows a high sinterability,and a relative density of 95% at a sintering temperature of 1 400 ℃.Electrochemistry measurements show that the CaZr0.1Ti0.9O3 ceramics has a relatively high oxide ionic conductivity(σ800 ℃=2.24×10-3 S/cm),low electrical activation energy(Ea=0.89 eV) in the low-temperature range.
2009, 26(11): 1324-1327
Abstract:
The Ni-Mo-Zr heteropoly salt with Keggin structure has been hydrothermally synthesized and characterized by IR and XRD.Efficiency of ultrasonic degradation of the heteropoly salt for the acidic-green B(AGB) dye as the objective compound was investigated,and the influence factors on the ultrasonic degradation efficiency,such as the amount of the heteropoly salt,the initial concentration and the pH value of the acidic-green B dye wastewater,were explored.The results show that newly synthesized Ni-Mo-Zr heteropoly salt had Keggin structure.When the amount of the heteropoly salt was 0.8 g/L,the initial concentration of the dye wastewater was 10 mg/L and the initial pH value of the wastewater was 5.0,and ultrasonic irradiation was carried out for 60 min at 40 kHz,the degradation rate was optimum and up to 90.2%.After dynamics analysis,it showed the degradation reaction was in accord with the first order dynamics model,and the degradation rate was decreased with the increasing of the initial concentration of the acidic-green B.
The Ni-Mo-Zr heteropoly salt with Keggin structure has been hydrothermally synthesized and characterized by IR and XRD.Efficiency of ultrasonic degradation of the heteropoly salt for the acidic-green B(AGB) dye as the objective compound was investigated,and the influence factors on the ultrasonic degradation efficiency,such as the amount of the heteropoly salt,the initial concentration and the pH value of the acidic-green B dye wastewater,were explored.The results show that newly synthesized Ni-Mo-Zr heteropoly salt had Keggin structure.When the amount of the heteropoly salt was 0.8 g/L,the initial concentration of the dye wastewater was 10 mg/L and the initial pH value of the wastewater was 5.0,and ultrasonic irradiation was carried out for 60 min at 40 kHz,the degradation rate was optimum and up to 90.2%.After dynamics analysis,it showed the degradation reaction was in accord with the first order dynamics model,and the degradation rate was decreased with the increasing of the initial concentration of the acidic-green B.
2009, 26(11): 1328-1331
Abstract:
SrFe(Cu,Ti)O3-δ mixed conducting membrane materials were synthesized by citric acid complexing method.The stabilities of the materials were studied by means of XRD,O2-TPD,H2-TPR and SEM.It was found that phase decomposition occurred in SrFe0.7Cu0.3O3-δ under a low oxygen partial pressure and a minor phase SrCuO2 was formed.The addition of Ti4+ greatly enhanced the structure stability of the material,and SrFe0.6Cu0.3Ti0.1O3-δ maintained single-phased perovskite structure.H2-TPR and O2-TPD results showed that the addition of Ti4+ increased the initial oxygen desorption temperature of the material,and the reduction temperature of the other metal ions.Slight phase decomposition was found on the He-side surface of SrFe0.6Cu0.3Ti0.1O3-δ membrane after oxygen permeating test and fresh small grains congregated at the boundary of the initial grains.SrFe0.6Cu0.3Ti0.1O3-δ exhibits a high stability during 66 h oxygen permeating process.
SrFe(Cu,Ti)O3-δ mixed conducting membrane materials were synthesized by citric acid complexing method.The stabilities of the materials were studied by means of XRD,O2-TPD,H2-TPR and SEM.It was found that phase decomposition occurred in SrFe0.7Cu0.3O3-δ under a low oxygen partial pressure and a minor phase SrCuO2 was formed.The addition of Ti4+ greatly enhanced the structure stability of the material,and SrFe0.6Cu0.3Ti0.1O3-δ maintained single-phased perovskite structure.H2-TPR and O2-TPD results showed that the addition of Ti4+ increased the initial oxygen desorption temperature of the material,and the reduction temperature of the other metal ions.Slight phase decomposition was found on the He-side surface of SrFe0.6Cu0.3Ti0.1O3-δ membrane after oxygen permeating test and fresh small grains congregated at the boundary of the initial grains.SrFe0.6Cu0.3Ti0.1O3-δ exhibits a high stability during 66 h oxygen permeating process.
2009, 26(11): 1332-1335
Abstract:
The interactions between SudanⅡ and Myoglobin(Mb) were investigated via fluorescence spectro-scopy.The experimental results suggest that there is strong interaction between SudanⅡ and Mb.The binding site number n is about 1 and the binding constant,K,is 3.84×107 L/mol.The position,type and energy of the interaction between SudanⅡ and Mb were investigated by means of the flexible molecule docking technology.It was obtained from the theoretical calculation that the values of potential energy,electrostatic energy and van der waals energy of the interaction between SudanⅡ and Mb are-9 419.9,-7 468.8,-1 951.0 kJ/mol,respectively.SudanⅡ can form hydrogen bonds with His64 of Mb.In addition,SudanⅡ can interact with Phe33,Phe43,Phe106 and Phe138 residues,which can produce fluorescence.Thus,the interaction can lead to the fluorescence quenching of Mb.This is in good agreement with the result of the fluorescence experiment.
The interactions between SudanⅡ and Myoglobin(Mb) were investigated via fluorescence spectro-scopy.The experimental results suggest that there is strong interaction between SudanⅡ and Mb.The binding site number n is about 1 and the binding constant,K,is 3.84×107 L/mol.The position,type and energy of the interaction between SudanⅡ and Mb were investigated by means of the flexible molecule docking technology.It was obtained from the theoretical calculation that the values of potential energy,electrostatic energy and van der waals energy of the interaction between SudanⅡ and Mb are-9 419.9,-7 468.8,-1 951.0 kJ/mol,respectively.SudanⅡ can form hydrogen bonds with His64 of Mb.In addition,SudanⅡ can interact with Phe33,Phe43,Phe106 and Phe138 residues,which can produce fluorescence.Thus,the interaction can lead to the fluorescence quenching of Mb.This is in good agreement with the result of the fluorescence experiment.
2009, 26(11): 1336-1340
Abstract:
Electrodialysis and Fenton reagent method were combined to decrease the concentration of NH4+-N and CODCr in landfill leachates by means of coupling membrane triple chamber cell.NH4+-N in landfill leachates was enriched in catholyte by electrodialysis,then removed by chemical precipitation.In the meantime,Fe2+ was generated at the Fe anode.H2O2 was dropped into the anolyte to produce Fenton reagent,which could degrade organic compounds and decrease the concentration of CODCr.The experimental results show that the removal rate of NH4+-N in simulated wastewater was up to 80%,and the concentrations of NH4+-N and CODCr in the landfill leachates were decreased from 1 982 mg/L and 2 248 mg/L to 200 mg/L and 127 mg/L,respectively.
Electrodialysis and Fenton reagent method were combined to decrease the concentration of NH4+-N and CODCr in landfill leachates by means of coupling membrane triple chamber cell.NH4+-N in landfill leachates was enriched in catholyte by electrodialysis,then removed by chemical precipitation.In the meantime,Fe2+ was generated at the Fe anode.H2O2 was dropped into the anolyte to produce Fenton reagent,which could degrade organic compounds and decrease the concentration of CODCr.The experimental results show that the removal rate of NH4+-N in simulated wastewater was up to 80%,and the concentrations of NH4+-N and CODCr in the landfill leachates were decreased from 1 982 mg/L and 2 248 mg/L to 200 mg/L and 127 mg/L,respectively.
2009, 26(11): 1341-1344
Abstract:
A method was developed to determine the concentration of activated species in strong ionized discharging plasma,which could be used to measure the apparent oxidation ability.In the experiments,the excess ferrous ions reacted with the activated species in plasma,and then the remained ferrous ions was titrated with potassium permanganate,the amount of which was used to determine the concentration of the activated species.Some influencing factors,such as pH value,flow of discharging gas,discharging power,pressure of discharging gas and reaction time,were evaluated,respectively.The results of experiments show that pH=6.0 was the proper initial pH value;the reaction time had less effect on the determination,so 3 minutes was suitable;the concentration of the activated species increased with the increases of discharging power and the pressure of discharging gas,but decreased with the increase of the flow of discharging gas.It has shown that the reproducibility and the sensitivity of the determination method are all satisfied,and the detection limit reaches 3.91×10-5 mol/L.
A method was developed to determine the concentration of activated species in strong ionized discharging plasma,which could be used to measure the apparent oxidation ability.In the experiments,the excess ferrous ions reacted with the activated species in plasma,and then the remained ferrous ions was titrated with potassium permanganate,the amount of which was used to determine the concentration of the activated species.Some influencing factors,such as pH value,flow of discharging gas,discharging power,pressure of discharging gas and reaction time,were evaluated,respectively.The results of experiments show that pH=6.0 was the proper initial pH value;the reaction time had less effect on the determination,so 3 minutes was suitable;the concentration of the activated species increased with the increases of discharging power and the pressure of discharging gas,but decreased with the increase of the flow of discharging gas.It has shown that the reproducibility and the sensitivity of the determination method are all satisfied,and the detection limit reaches 3.91×10-5 mol/L.
2009, 26(11): 1345-1348
Abstract:
pH-open circuit potential relationship was investigated for Ir/IrO2 micro plane pH sensing electrode on the primary alcohols oxidizing electrode surface.pH value at a distance apart from oxidizing electrode surface within 50 μm was measured during electrochemical oxidation of three primary alcohols.Comparison and analysis were made for the H+ concentration generated by electrochemical oxidation of the primary alcohols.The experiment reveals that the relationship between "pH-open circuit potential" of the Ir/IrO2 micro plane electrode is related to the kind of "alcohol-carboxylic acid" system.The H+ concentration generated by electrochemical oxidation of glycol is the highest,methanol's comes the second,and ethanol's is the lowest.Under steady state diffusion,their pH values were 0.191,1.13 and 2.99 at 500 nm from oxidizing electrode surface respectivly.Through the addition of NaF in the electrolyte,the selective micro-area etching function of HF formed by the association of H+ and F- for titanium was examined.In the glycol oxidation system,the etching rate for microhole on titanium was about 30 nm/min.
pH-open circuit potential relationship was investigated for Ir/IrO2 micro plane pH sensing electrode on the primary alcohols oxidizing electrode surface.pH value at a distance apart from oxidizing electrode surface within 50 μm was measured during electrochemical oxidation of three primary alcohols.Comparison and analysis were made for the H+ concentration generated by electrochemical oxidation of the primary alcohols.The experiment reveals that the relationship between "pH-open circuit potential" of the Ir/IrO2 micro plane electrode is related to the kind of "alcohol-carboxylic acid" system.The H+ concentration generated by electrochemical oxidation of glycol is the highest,methanol's comes the second,and ethanol's is the lowest.Under steady state diffusion,their pH values were 0.191,1.13 and 2.99 at 500 nm from oxidizing electrode surface respectivly.Through the addition of NaF in the electrolyte,the selective micro-area etching function of HF formed by the association of H+ and F- for titanium was examined.In the glycol oxidation system,the etching rate for microhole on titanium was about 30 nm/min.
2009, 26(11): 1349-1352
Abstract:
In an alkaline solution,Ag+ can be reduced by formaldehyde to form silver nanoparticles,leading to the resonance light scattering(RLS) intensities of the system to be enhanced.Based on these phenomena,a new RLS method for trace formaldehyde determination in environment water samples was established.Under the optimized reaction conditions,the enhanced RLS intensities of the system has a good relationship with the concentration of formaldehyde in a range of 1.0×10-6～2.0×10-5 mol/L with the detection limit of 1.0×10-7 mol/L.The standard addition recovery ratio is in a range of 96.26% to 103.32% for formaldehyde detection in environmental water samples and in the indoor air.According to the phenomenon that the resultant from the reaction of Ag+ and formaldehyde has different colors in the presence of formaldehyde with different concentrations,a visual semi-quantificational method for detection of formaldehyde could be achieved.
In an alkaline solution,Ag+ can be reduced by formaldehyde to form silver nanoparticles,leading to the resonance light scattering(RLS) intensities of the system to be enhanced.Based on these phenomena,a new RLS method for trace formaldehyde determination in environment water samples was established.Under the optimized reaction conditions,the enhanced RLS intensities of the system has a good relationship with the concentration of formaldehyde in a range of 1.0×10-6～2.0×10-5 mol/L with the detection limit of 1.0×10-7 mol/L.The standard addition recovery ratio is in a range of 96.26% to 103.32% for formaldehyde detection in environmental water samples and in the indoor air.According to the phenomenon that the resultant from the reaction of Ag+ and formaldehyde has different colors in the presence of formaldehyde with different concentrations,a visual semi-quantificational method for detection of formaldehyde could be achieved.
2009, 26(11): 1353-1356
Abstract:
Synergistic effect on the extraction of molybdenum by the mixed extractants of di-2-ethylhexyl phosphoric acid(P204) and trialkylamine N235 was investigated.The mixed system showed an obvious enhancement on the extraction of molybdenum with a mole fraction of N235 being about 0.7.The effects of the aqueous acidity,the concentration of P204 or N235 and temperature on the extraction of molybdenum were further studied.The reaction mechanism was deduced and the extracted species was determined to be(R3NH)3·HMo8O26·(HA)3.FT-IR spectra of the mixed extractants and the loaded organic phase were examined.
Synergistic effect on the extraction of molybdenum by the mixed extractants of di-2-ethylhexyl phosphoric acid(P204) and trialkylamine N235 was investigated.The mixed system showed an obvious enhancement on the extraction of molybdenum with a mole fraction of N235 being about 0.7.The effects of the aqueous acidity,the concentration of P204 or N235 and temperature on the extraction of molybdenum were further studied.The reaction mechanism was deduced and the extracted species was determined to be(R3NH)3·HMo8O26·(HA)3.FT-IR spectra of the mixed extractants and the loaded organic phase were examined.
2009, 26(11): 1357-1361
Abstract:
A new method was proposed for the determination of moroxydine hydrochloride with sodium nitroprusside by spectrophotometry.Colored N-nitrosamine product was formed by moroxydine hydrochloride and sodium nitroprusside in alkaline solution.The liner regression equation is A=0.022 92+0.012 13c(10-6 g/mL) with a correlation coefficient of 0.999 8,and ε was 2.5×103 L/(mol·cm) at 508 nm.Beer's law was well obeyed in a range of moroxydine hydrochloride concentration of 0.38×10-6～3.0×10-4 g/mL,the limit of detection(3σ/k) was 0.25×10-6 g/mL,the RSD was 0.21%.The method was used for the determination of moroxydine hydrochloride in pharmaceutical samples and human serum with satisfactory results.
A new method was proposed for the determination of moroxydine hydrochloride with sodium nitroprusside by spectrophotometry.Colored N-nitrosamine product was formed by moroxydine hydrochloride and sodium nitroprusside in alkaline solution.The liner regression equation is A=0.022 92+0.012 13c(10-6 g/mL) with a correlation coefficient of 0.999 8,and ε was 2.5×103 L/(mol·cm) at 508 nm.Beer's law was well obeyed in a range of moroxydine hydrochloride concentration of 0.38×10-6～3.0×10-4 g/mL,the limit of detection(3σ/k) was 0.25×10-6 g/mL,the RSD was 0.21%.The method was used for the determination of moroxydine hydrochloride in pharmaceutical samples and human serum with satisfactory results.
2009, 26(11): 1362-1366
Abstract:
A novel sorbent,nano-TiO2 was employed for the removal of molybdenum and rhenium from aqueous solution in batch equilibrium experiments in order to investigate their adsorption properties.The removal percentage of molybdenum by the sorbent is closed to 99% in a pH range of 1～8.The elution rate of molybdenum with 2 mL of 0.05 mol/L NaOH is closed to 97%.As rhenium is hardly adsorbed onto nano-TiO2,molybdenum and rhenium can be separated.The adsorption capacities and removal percentage of Mo(Ⅵ) onto nano-TiO2 were evaluated as a function of the solution concentration and temperature.Results have been analyzed by means of the Langmuir,Freundlich adsorption isotherms.Adsorption isothermal data could be well interpreted by the Langmuir model.Saturated adsorption capacity increases from 11.51mg/g to 14.19 mg/g in a temperature range of 275～323 K.The removal percentage of Re(Ⅶ) by the actived carbon is closed to 99% in a pH range of 1～10.The results showed that the elution rate of Re(Ⅶ) with strong ammonia is 96%.Adsorption isothermal data could be well interpreted by the Freundlich model.The kinetic experimental data of Re(Ⅶ) are properly correlated with the second-order kinetic model.
A novel sorbent,nano-TiO2 was employed for the removal of molybdenum and rhenium from aqueous solution in batch equilibrium experiments in order to investigate their adsorption properties.The removal percentage of molybdenum by the sorbent is closed to 99% in a pH range of 1～8.The elution rate of molybdenum with 2 mL of 0.05 mol/L NaOH is closed to 97%.As rhenium is hardly adsorbed onto nano-TiO2,molybdenum and rhenium can be separated.The adsorption capacities and removal percentage of Mo(Ⅵ) onto nano-TiO2 were evaluated as a function of the solution concentration and temperature.Results have been analyzed by means of the Langmuir,Freundlich adsorption isotherms.Adsorption isothermal data could be well interpreted by the Langmuir model.Saturated adsorption capacity increases from 11.51mg/g to 14.19 mg/g in a temperature range of 275～323 K.The removal percentage of Re(Ⅶ) by the actived carbon is closed to 99% in a pH range of 1～10.The results showed that the elution rate of Re(Ⅶ) with strong ammonia is 96%.Adsorption isothermal data could be well interpreted by the Freundlich model.The kinetic experimental data of Re(Ⅶ) are properly correlated with the second-order kinetic model.
2009, 26(11): 1367-1370
Abstract:
The structure parameters EHOMO,ELUMO,q+,q-,μ,Etotal of seventeen solvents such as water,alcohols,aldehydes,esters,fluoroalkanes were calculated at B3LYP/6-31G(d) level.By means of error back-propagation(BP) algorithm artificial neural network(ANN) and 7 hidden layer units,the relationship between each of EHOMO,ELUMOq+,q-,μ,Etotal,VM,ε,T and solubility of hydrocortisone in various solvents at different temperatures were established.The solubilities of hydrocortisone under various conditions were predicted by virture of ANN with an average relative error of 7.0%.
The structure parameters EHOMO,ELUMO,q+,q-,μ,Etotal of seventeen solvents such as water,alcohols,aldehydes,esters,fluoroalkanes were calculated at B3LYP/6-31G(d) level.By means of error back-propagation(BP) algorithm artificial neural network(ANN) and 7 hidden layer units,the relationship between each of EHOMO,ELUMOq+,q-,μ,Etotal,VM,ε,T and solubility of hydrocortisone in various solvents at different temperatures were established.The solubilities of hydrocortisone under various conditions were predicted by virture of ANN with an average relative error of 7.0%.
2009, 26(11): 1371-1373
Abstract:
A novel chiral polydentate ligand,2-ethoxy-4-(2-methoxy-ethoxy)-6-((1R,2R)-1,2-diphenyl-2-methoxy-ethoxy)-1,3,5-triazine,was synthesized from(R,R)-hydrobenzoin and cyanuric chloride by means of functional group pretection,etherification,deprotection and substitution.The structure of the target product was characterized by 1H NMR,LCMS and elemental analysis.
A novel chiral polydentate ligand,2-ethoxy-4-(2-methoxy-ethoxy)-6-((1R,2R)-1,2-diphenyl-2-methoxy-ethoxy)-1,3,5-triazine,was synthesized from(R,R)-hydrobenzoin and cyanuric chloride by means of functional group pretection,etherification,deprotection and substitution.The structure of the target product was characterized by 1H NMR,LCMS and elemental analysis.
2009, 26(11): 1374-1376
Abstract:
1,2-Cyclododecandione(4) was synthesized from dodecanedioic acid via esterification,acyloin condensation,oxidation in an overall yield of 43.1%.Reaction of dodecanedioic acid with methanol gave dodecanedioic acid dimethyl ester(2) with a yield of 86.5%.Compound 3 was obtained from compound 2 through acyloin condensation and the yield reached up to 63.1%,which was oxidized to compound 4 by bromine water as the oxidation reagent with a yield of 79%.The target compound was a light yellow crystal and was characterized by means of IR,1H NMR and 13C NMR.
1,2-Cyclododecandione(4) was synthesized from dodecanedioic acid via esterification,acyloin condensation,oxidation in an overall yield of 43.1%.Reaction of dodecanedioic acid with methanol gave dodecanedioic acid dimethyl ester(2) with a yield of 86.5%.Compound 3 was obtained from compound 2 through acyloin condensation and the yield reached up to 63.1%,which was oxidized to compound 4 by bromine water as the oxidation reagent with a yield of 79%.The target compound was a light yellow crystal and was characterized by means of IR,1H NMR and 13C NMR.
