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2008 Volume 25 Issue 7
2008, 25(7): 753-758
Abstract:
The photoelectrochemical behavior of the TiO2 nanocrystalline electrode sensitized by Cy3 (novel squarylium cyanine dye) was studied.The ground state level and the excited state level of the dye were determined by means of cyclic voltammetry and optical absorption spectroscopy.The results showed that the excited state level of this dye matches the conduction band edge of TiO2 nanoparticles.Therefore the sensitization of TiO2 nanocrystalline electrode with the dye can obviously increase the photocurrent density and result in a red-shift of optical absorption from the ultra-violet region to the visible region.As a result,the light-to-electricity conversion efficiency was greatly improved and the maximum value of IPCE reached 22.9% and η was 1.37% when the TiO2 nanostructured porous film was 6.5 μm thick and was sensitized for 4 h.The values above mentioned could be improved to 29.0% and 1.51% after the sensitized electrode was treated with methanol.
The photoelectrochemical behavior of the TiO2 nanocrystalline electrode sensitized by Cy3 (novel squarylium cyanine dye) was studied.The ground state level and the excited state level of the dye were determined by means of cyclic voltammetry and optical absorption spectroscopy.The results showed that the excited state level of this dye matches the conduction band edge of TiO2 nanoparticles.Therefore the sensitization of TiO2 nanocrystalline electrode with the dye can obviously increase the photocurrent density and result in a red-shift of optical absorption from the ultra-violet region to the visible region.As a result,the light-to-electricity conversion efficiency was greatly improved and the maximum value of IPCE reached 22.9% and η was 1.37% when the TiO2 nanostructured porous film was 6.5 μm thick and was sensitized for 4 h.The values above mentioned could be improved to 29.0% and 1.51% after the sensitized electrode was treated with methanol.
2008, 25(7): 759-762
Abstract:
The mesoporous SBA-16 thin films were synthesized with ITO as the substrate under acidic condition.The prepared SBA-16 thin films with narrow pore size distribution have a body-centered cubic structure (Im3m space group).In recent years,ITO-coated glass or AAO has been used as the substrates for the electrodeposition of CdS,while work on using mesoporous molecular sieves films/ITO as the substrate has not appeared.In an electrolyte solution composed of CdCl2 and Na2S2O3 with a modulated pH value of 2~3, "flower-like" nanocrystalline CdS was electrodeposited on the surface of SBA-16 thin films/ITO electrode via the DC electrodeposition method at a constant potential of -0.7 V for 50 min.The morphology and structure of the products were characterized by SEM,TEM and the PL properties were tested.The results show that the nanocrystalline CdS was grown on the surface of the electrode and not in the mesopores and showed PL properties.
The mesoporous SBA-16 thin films were synthesized with ITO as the substrate under acidic condition.The prepared SBA-16 thin films with narrow pore size distribution have a body-centered cubic structure (Im3m space group).In recent years,ITO-coated glass or AAO has been used as the substrates for the electrodeposition of CdS,while work on using mesoporous molecular sieves films/ITO as the substrate has not appeared.In an electrolyte solution composed of CdCl2 and Na2S2O3 with a modulated pH value of 2~3, "flower-like" nanocrystalline CdS was electrodeposited on the surface of SBA-16 thin films/ITO electrode via the DC electrodeposition method at a constant potential of -0.7 V for 50 min.The morphology and structure of the products were characterized by SEM,TEM and the PL properties were tested.The results show that the nanocrystalline CdS was grown on the surface of the electrode and not in the mesopores and showed PL properties.
2008, 25(7): 763-767
Abstract:
Based on the photosensitive properties of tetra-substituted zinc phthalocyanine (p-HPcZn),the interaction of p-HPcZn with calf thymus DNA (CT DNA) was investigated by UV-Vis and fluorescence spectroscopies.It was found that p-HPcZn could insert into the double-helix of DNA.In addition,the result of CT-DNA photodamage experiments suggests that the photodamage ability of p-HPcZn is higher than that of hematoporphyrin in the presence or absence of oxygen.
Based on the photosensitive properties of tetra-substituted zinc phthalocyanine (p-HPcZn),the interaction of p-HPcZn with calf thymus DNA (CT DNA) was investigated by UV-Vis and fluorescence spectroscopies.It was found that p-HPcZn could insert into the double-helix of DNA.In addition,the result of CT-DNA photodamage experiments suggests that the photodamage ability of p-HPcZn is higher than that of hematoporphyrin in the presence or absence of oxygen.
2008, 25(7): 768-772
Abstract:
A series of poly (hydroquinone ether)s containing propanetriol units were prepared from hydroquinone and epoxy chloropropane in good yields.The oligomers can self-assemble into a novel pseudorotaxane with π-electron-deficient bipyridinium cyclophane (CPQT) via π-π stacking interaction and weak interaction.The partial temperature-dependent 1H NMR spectra of pseudorotaxane between poly (hydroquinone ether) and CPQT showed that the chemical shift changes of different aromatic rings in the 1:1 complex formed between ether chain and CPQT were different.However,the chemical shift changes of different aromatic rings in the 1:2 complex or 1:3 complex formed between ether chain and CPQT were the same.They can become molecular device which may be controlled at a molecular level.
A series of poly (hydroquinone ether)s containing propanetriol units were prepared from hydroquinone and epoxy chloropropane in good yields.The oligomers can self-assemble into a novel pseudorotaxane with π-electron-deficient bipyridinium cyclophane (CPQT) via π-π stacking interaction and weak interaction.The partial temperature-dependent 1H NMR spectra of pseudorotaxane between poly (hydroquinone ether) and CPQT showed that the chemical shift changes of different aromatic rings in the 1:1 complex formed between ether chain and CPQT were different.However,the chemical shift changes of different aromatic rings in the 1:2 complex or 1:3 complex formed between ether chain and CPQT were the same.They can become molecular device which may be controlled at a molecular level.
2008, 25(7): 773-776
Abstract:
Poly-epoxy-succinic acid (PESA),as an environmental benign chelant,was used to remove zinc from the sewage sludge of Shanghai Taopu Wastewater Treatment Plant.Extraction of sewage sludge with aqueous solution of PESA was carried out under various conditions.The influences of pH and concentration of PESA on the extraction efficiency for zinc were investigated.The results show that PESA has a higher extraction efficiency of zinc from sludge than those of other heavy metals,and the extracted zinc mainly comes from the water soluble,acid soluble and reducible fractions.It was found that pH and concentration of PESA have a significant effect on the extraction efficiency of zinc.The extraction efficiency for zinc decreases gradually with pH increasing.When the concentration of PESA increases,the extraction efficiency of zinc increases and the effect of pH decreases.The extraction efficiency of zinc reaches above 70% when pH is 4 and the molar ratio of PESA to total amount of heavy metals ranges from 3 to 10.
Poly-epoxy-succinic acid (PESA),as an environmental benign chelant,was used to remove zinc from the sewage sludge of Shanghai Taopu Wastewater Treatment Plant.Extraction of sewage sludge with aqueous solution of PESA was carried out under various conditions.The influences of pH and concentration of PESA on the extraction efficiency for zinc were investigated.The results show that PESA has a higher extraction efficiency of zinc from sludge than those of other heavy metals,and the extracted zinc mainly comes from the water soluble,acid soluble and reducible fractions.It was found that pH and concentration of PESA have a significant effect on the extraction efficiency of zinc.The extraction efficiency for zinc decreases gradually with pH increasing.When the concentration of PESA increases,the extraction efficiency of zinc increases and the effect of pH decreases.The extraction efficiency of zinc reaches above 70% when pH is 4 and the molar ratio of PESA to total amount of heavy metals ranges from 3 to 10.
2008, 25(7): 777-782
Abstract:
The effect of the aggregation state of microperoxidase-11(MP-11) on its interaction with Yb3+ was investigated.The results of the UV-Vis absorption spectroscopic investigation indicate that Yb3+ would be coordinated with carboxylate oxygen of two propionic acid groups of the heme group in an MP-11 molecule,leading to the increase in the non-planarity of the porphyrin ring of the heme group,the decrease in the energy for the π-π* transition and the reduction in the electron transition probability.Thus,after the addition of Yb3+,the position of the Soret band of MP-11 in the UV-Vis absorption spectrum of MP-11 was red-shifted by 10 nm and its absorbance was reduced by 35%.Although NaCl can increase the aggregation extent of MP-11 molecules,the existence of a large amount of Na+ ions would reduce the interaction between Yb3+ and MP-11.Thus,after addition of Yb3+,the position of the Soret band was not changed and its absorbance was only reduced by 5%.Methanol can reduce the aggregation extent of MP-11 molecules and thus,increase the exposure extent.Therefore,methanol can increase the absorbance of the Soret band with a certain extent.
The effect of the aggregation state of microperoxidase-11(MP-11) on its interaction with Yb3+ was investigated.The results of the UV-Vis absorption spectroscopic investigation indicate that Yb3+ would be coordinated with carboxylate oxygen of two propionic acid groups of the heme group in an MP-11 molecule,leading to the increase in the non-planarity of the porphyrin ring of the heme group,the decrease in the energy for the π-π* transition and the reduction in the electron transition probability.Thus,after the addition of Yb3+,the position of the Soret band of MP-11 in the UV-Vis absorption spectrum of MP-11 was red-shifted by 10 nm and its absorbance was reduced by 35%.Although NaCl can increase the aggregation extent of MP-11 molecules,the existence of a large amount of Na+ ions would reduce the interaction between Yb3+ and MP-11.Thus,after addition of Yb3+,the position of the Soret band was not changed and its absorbance was only reduced by 5%.Methanol can reduce the aggregation extent of MP-11 molecules and thus,increase the exposure extent.Therefore,methanol can increase the absorbance of the Soret band with a certain extent.
2008, 25(7): 783-786
Abstract:
To discover a novel structural lead compound for developing antitumor agents,4-amino-5-pyridin-3-yl-1,2,4-triazole-3-thiol (1) was S-etherized with iodomethane to give the intermediate of 4-amino-3-methylsulfanyl-5-pyridin-3-yl-1,2,4-triazole (2) followed by condensation with various aromatic aldehydes to afford the title compounds of seven novel Schiff bases,4-(aromatic methyl) imino-3-methylsulfanyl-5-pyridin-3-yl-1,2,4-triazoles (3a~3g).Their antitumor activity against SMMC-7721 and Bel-7402 cells were evaluated by MTT method in vitro,and their structures were characterized by IR,1H NMR,MS spectrum data and elemental analysis.Among synthesized compounds,3c,3e and 3f showed potential antitumor activity with the IC50 of 3.8,2.0,1.3 and 2.5,2.5,1.1 μmol/L against SMMC-7721 and Bel-7402 cells,respectively.
To discover a novel structural lead compound for developing antitumor agents,4-amino-5-pyridin-3-yl-1,2,4-triazole-3-thiol (1) was S-etherized with iodomethane to give the intermediate of 4-amino-3-methylsulfanyl-5-pyridin-3-yl-1,2,4-triazole (2) followed by condensation with various aromatic aldehydes to afford the title compounds of seven novel Schiff bases,4-(aromatic methyl) imino-3-methylsulfanyl-5-pyridin-3-yl-1,2,4-triazoles (3a~3g).Their antitumor activity against SMMC-7721 and Bel-7402 cells were evaluated by MTT method in vitro,and their structures were characterized by IR,1H NMR,MS spectrum data and elemental analysis.Among synthesized compounds,3c,3e and 3f showed potential antitumor activity with the IC50 of 3.8,2.0,1.3 and 2.5,2.5,1.1 μmol/L against SMMC-7721 and Bel-7402 cells,respectively.
2008, 25(7): 787-791
Abstract:
The isothermal curing kinetics of polyhedral oligomeric silsesquioxane-epoxy resin (POSSER) with 4,4'-Diaminodiphenylsulfone (DDS) as a curing agent was studied by means of differential scanning calorimetry (DSC).Analysis of DSC data indicates that an autocatalytic behavior occurred in the overall curing process,which can be described with the model proposed by Kamal that includes two rate constants,k1,k2,and two reaction orders,m and n.Rate constants k1 and k2 were observed to be greater when curing temperature increased.The overall reaction order,m+n,is in a range of 1~1.6.The activation energies for k1 and k2 were 79.67 kJ/mol and 59.84 kJ/mol,respectively.
The isothermal curing kinetics of polyhedral oligomeric silsesquioxane-epoxy resin (POSSER) with 4,4'-Diaminodiphenylsulfone (DDS) as a curing agent was studied by means of differential scanning calorimetry (DSC).Analysis of DSC data indicates that an autocatalytic behavior occurred in the overall curing process,which can be described with the model proposed by Kamal that includes two rate constants,k1,k2,and two reaction orders,m and n.Rate constants k1 and k2 were observed to be greater when curing temperature increased.The overall reaction order,m+n,is in a range of 1~1.6.The activation energies for k1 and k2 were 79.67 kJ/mol and 59.84 kJ/mol,respectively.
2008, 25(7): 792-796
Abstract:
The electrochemical behavior of ofloxacin at glassy carbon electrode (GCE) modified with aligned carbon nanotubes (ACNTs) was investigated.The results showed the oxidation peak current of ofloxacin increased significantly at the ACNTs-modified GCE in comparison with that at bared GCE.The experiment parameters such as the type and acidity of the electrolyte,the accumulation time,the thickness of the ACNTs-modified layer and scan rate were optimized.Linear correlation between the oxidation peak current and the concentration of ofloxacin was found over a range from 8.0×10-7 to 2.0×10-3 mol/L with a detection limit of 3.2×10-7 mol/L.In 0.1 mol/L Britton-Robinson buffer solution (pH 7.0),the presence of a lot of metal ions and ascorbic acid and urin etc did not interfere with the determination of ofloxacin.The relative standard deviation (RSD) of ten measurements was 4.2% for ofloxacin,indicating good reproducibility.This method was used to determine the ofloxacin concentration in real ofloxacin samples with good results.
The electrochemical behavior of ofloxacin at glassy carbon electrode (GCE) modified with aligned carbon nanotubes (ACNTs) was investigated.The results showed the oxidation peak current of ofloxacin increased significantly at the ACNTs-modified GCE in comparison with that at bared GCE.The experiment parameters such as the type and acidity of the electrolyte,the accumulation time,the thickness of the ACNTs-modified layer and scan rate were optimized.Linear correlation between the oxidation peak current and the concentration of ofloxacin was found over a range from 8.0×10-7 to 2.0×10-3 mol/L with a detection limit of 3.2×10-7 mol/L.In 0.1 mol/L Britton-Robinson buffer solution (pH 7.0),the presence of a lot of metal ions and ascorbic acid and urin etc did not interfere with the determination of ofloxacin.The relative standard deviation (RSD) of ten measurements was 4.2% for ofloxacin,indicating good reproducibility.This method was used to determine the ofloxacin concentration in real ofloxacin samples with good results.
2008, 25(7): 797-802
Abstract:
Polystyrene was grafted on micron-sized silica gel particles in "grafting manner" in a solution polymerization system,and grafted particles PS/SiO2 were prepared.Then the grafted polystyrene was chlorome-thylated with a novel chloromethylation reagent,1,4-bis(chloromethoxy) butane,and grafted particles CMPS/SiO2,to which chloromethylated polystyrene was attached,were obtained.Finally,the quaternization between benzyl chloride on the macromolecular chains of CMPS and tertiary amine agent,and composite-type functional particles QPS/SiO2,on which quaternary ammonium salt was supported,were gained.The chemical structure and composition of QPS/SiO2 were characterized with FTIR and chemical analysis method.The effects of various factors on the quaternization of CMPS/SiO2 were studied.The antibacterial activity of QPS/SiO2 against Escherichia coil was studied preliminarily.The experimental results show that the quaternization of CMPS/SiO2 is easy to carry out.The polarity of solvent,the kinds of tertiary amine agents and the reaction temperature all influenced the quaternization.The quaternary degree of the product is higher as the fine solvent of CMPS is used and tertiary amine agent with smaller steric hindrance is used.QPS/SiO2 possesses a very high antibacterial activity,and the antibacterial ratio can reach to 100% only with a dosage of 10 g/L during a short contact of 3 min,indicating that QPS/SiO2 is an excellent water-insoluble antibacterial material.The antibacterial ability of QPS/SiO2 with higher quaternary degree is stronger,and QPS/SiO2 prepared from tributyl amine that has longer hydrocarbon chain has a higher antibacterial activity.
Polystyrene was grafted on micron-sized silica gel particles in "grafting manner" in a solution polymerization system,and grafted particles PS/SiO2 were prepared.Then the grafted polystyrene was chlorome-thylated with a novel chloromethylation reagent,1,4-bis(chloromethoxy) butane,and grafted particles CMPS/SiO2,to which chloromethylated polystyrene was attached,were obtained.Finally,the quaternization between benzyl chloride on the macromolecular chains of CMPS and tertiary amine agent,and composite-type functional particles QPS/SiO2,on which quaternary ammonium salt was supported,were gained.The chemical structure and composition of QPS/SiO2 were characterized with FTIR and chemical analysis method.The effects of various factors on the quaternization of CMPS/SiO2 were studied.The antibacterial activity of QPS/SiO2 against Escherichia coil was studied preliminarily.The experimental results show that the quaternization of CMPS/SiO2 is easy to carry out.The polarity of solvent,the kinds of tertiary amine agents and the reaction temperature all influenced the quaternization.The quaternary degree of the product is higher as the fine solvent of CMPS is used and tertiary amine agent with smaller steric hindrance is used.QPS/SiO2 possesses a very high antibacterial activity,and the antibacterial ratio can reach to 100% only with a dosage of 10 g/L during a short contact of 3 min,indicating that QPS/SiO2 is an excellent water-insoluble antibacterial material.The antibacterial ability of QPS/SiO2 with higher quaternary degree is stronger,and QPS/SiO2 prepared from tributyl amine that has longer hydrocarbon chain has a higher antibacterial activity.
2008, 25(7): 803-809
Abstract:
Dehydroabietic acid was refluxed with thionyl chloride for 6 h to yield acetyl chloride,which was refluxed with KSCN in anhydrous acetonitrile for 1.5 h to provide dehydroabieticacyl isothiocyanate 3 in a yield of 52%.A series of 1-dehydroabieticacyl-3-aroylthiosemicarbazides 4 were obtained from the reaction of compound 3 with each of 4-substituted benzoylhydrazides in yields of 39%~84%,and compounds 4 were treated under the catalysis of glacier acetic acid,giving their ring closure products 5-aryl-2-dehydroabieticacyl-amido-1,3,4-thiadiazoles 5 in 49%~87% yields.All the target compounds were characterized by IR,1H NMR,and 13C NMR;the crystal structure of 5b was analyzed by X-ray crystallography.The preliminary biological tests showed that some of the title compounds (4c,4f,5f) possessed a fungicidal activity against B.subtilis and E.coli at test concentration (100 mg/L).
Dehydroabietic acid was refluxed with thionyl chloride for 6 h to yield acetyl chloride,which was refluxed with KSCN in anhydrous acetonitrile for 1.5 h to provide dehydroabieticacyl isothiocyanate 3 in a yield of 52%.A series of 1-dehydroabieticacyl-3-aroylthiosemicarbazides 4 were obtained from the reaction of compound 3 with each of 4-substituted benzoylhydrazides in yields of 39%~84%,and compounds 4 were treated under the catalysis of glacier acetic acid,giving their ring closure products 5-aryl-2-dehydroabieticacyl-amido-1,3,4-thiadiazoles 5 in 49%~87% yields.All the target compounds were characterized by IR,1H NMR,and 13C NMR;the crystal structure of 5b was analyzed by X-ray crystallography.The preliminary biological tests showed that some of the title compounds (4c,4f,5f) possessed a fungicidal activity against B.subtilis and E.coli at test concentration (100 mg/L).
2008, 25(7): 810-814
Abstract:
The catalysing activities of Pt/Pt and Pt-Sn/Pt electrodes with different Pt:Sn ratios were investigated with conventional electrochemical technique for ethylene glycol (EG) oxidation.The self-dissociation phenomenon of EG to produce strong adsorption intermediate COad at Pt/Pt and Pt-Sn/Pt electrodes was found for the first time.And with the additive of Sn the self-oxidation dissociation of EG at Pt-Sn/Pt electrodes was suppressed.The adsorption quantity of CO produced by the self oxidation dissociation of EG at Pt-Sn/Pt electrodes decreased with increasing Sn:Pt ratio (from 4:1 to 3:2).The apparent activation energy of EG electro-oxidation also decreased (from 44.21 to 32.11 kJ/mol) with increasing Sn-Pt ratio.Compared with Pt/Pt electrode,the onset oxidation potential and apex oxidation potential of EG oxidation shifted negatively by 195 and 105 mV respectively,and the current inreased from 0.117 1 to 0.148 1 mA.
The catalysing activities of Pt/Pt and Pt-Sn/Pt electrodes with different Pt:Sn ratios were investigated with conventional electrochemical technique for ethylene glycol (EG) oxidation.The self-dissociation phenomenon of EG to produce strong adsorption intermediate COad at Pt/Pt and Pt-Sn/Pt electrodes was found for the first time.And with the additive of Sn the self-oxidation dissociation of EG at Pt-Sn/Pt electrodes was suppressed.The adsorption quantity of CO produced by the self oxidation dissociation of EG at Pt-Sn/Pt electrodes decreased with increasing Sn:Pt ratio (from 4:1 to 3:2).The apparent activation energy of EG electro-oxidation also decreased (from 44.21 to 32.11 kJ/mol) with increasing Sn-Pt ratio.Compared with Pt/Pt electrode,the onset oxidation potential and apex oxidation potential of EG oxidation shifted negatively by 195 and 105 mV respectively,and the current inreased from 0.117 1 to 0.148 1 mA.
2008, 25(7): 815-819
Abstract:
To obtain new composite materials with excellent anticorrosion properties in seawater and microbial environment,a series of Ni-P-Cr composite coatings containing TiO2 nanoglobes,TiO2 nanotubes and TiO2 nanowires respectively were prepared from plating solution by electrodeposition.The morphology of the TiO2 materials was investigated by TEM.The surface morphology and the elemental composition of the prepared composite coatings were investigated by SEM and EDX.The anticorrosion properties of the composite coatings were studied via polarization curves in artificial seawater (3.5% NaCl solution) and electrochemical impedance spectra (EIS) in culture medium in the presence of sulphate reducing bacteria (SRB).The results showed that the Ni-P-Cr composite coating containing TiO2 nanotubes exhibited good anticorrosion properties in artificial seawater and culture medium in the presence of SRB.
To obtain new composite materials with excellent anticorrosion properties in seawater and microbial environment,a series of Ni-P-Cr composite coatings containing TiO2 nanoglobes,TiO2 nanotubes and TiO2 nanowires respectively were prepared from plating solution by electrodeposition.The morphology of the TiO2 materials was investigated by TEM.The surface morphology and the elemental composition of the prepared composite coatings were investigated by SEM and EDX.The anticorrosion properties of the composite coatings were studied via polarization curves in artificial seawater (3.5% NaCl solution) and electrochemical impedance spectra (EIS) in culture medium in the presence of sulphate reducing bacteria (SRB).The results showed that the Ni-P-Cr composite coating containing TiO2 nanotubes exhibited good anticorrosion properties in artificial seawater and culture medium in the presence of SRB.
2008, 25(7): 820-824
Abstract:
4-(2-Hydroxyphenyl) but-3-en-2-one was prepared from 2-hydroxybenzaldehyde,which then reacted with hydrazine monohydrate.Ten new 1-(5-(2-hydroxy) phenyl)-3-methy-4,5-dihydropyrazol-1-yl) ethanone oxime ester derivatives were synthesized and characterized by elemental analysis,IR and 1H NMR.The compounds were evaluated for their fungicidal activity.The results showed that the title compounds displayed good fungicidal activity against Gibberella (inhibition ratio of compounds 5f towards Gibberella at 50 mg/L was 81.3%);compounds 5g and 5i showed certain fungicidal activity against H.Oryzae.The title compounds showed poor fungicidal activity against P.oryza.
4-(2-Hydroxyphenyl) but-3-en-2-one was prepared from 2-hydroxybenzaldehyde,which then reacted with hydrazine monohydrate.Ten new 1-(5-(2-hydroxy) phenyl)-3-methy-4,5-dihydropyrazol-1-yl) ethanone oxime ester derivatives were synthesized and characterized by elemental analysis,IR and 1H NMR.The compounds were evaluated for their fungicidal activity.The results showed that the title compounds displayed good fungicidal activity against Gibberella (inhibition ratio of compounds 5f towards Gibberella at 50 mg/L was 81.3%);compounds 5g and 5i showed certain fungicidal activity against H.Oryzae.The title compounds showed poor fungicidal activity against P.oryza.
2008, 25(7): 825-828
Abstract:
La0.7Sr0.3-xKxMnO3(0.05≤x≤0.3) powders were prepared by sol-gel technique.The samples were characterized by X-ray diffraction,SEM and VSM.A structure transition of La0.7Sr0.3-xKxMnO3 with x increasing from tetrahedron to monoclinic was observed.The morphology of La0.7Sr0.3-xKxMnO3 is inhomo-geneous ball with diameters of 100~500 nm.The Curie temperature and magnetization of La0.7Sr0.3-xKxMnO3 decrease with x increasing.When x=0.2,Tc (309 K) is near room temperature.This is the result of the Mn4+/Mn3+ ratio increasing,average ionic radii increasing and ionic mismatch enhancement.La0.7Sr0.1K0.2-MnO3 shows a larger magnetic entropy of ΔSM=3.28 J/(Kg·K) near Tc due to strong magnetism and crystal lattice coupling effect in doped perovskite oxides.
La0.7Sr0.3-xKxMnO3(0.05≤x≤0.3) powders were prepared by sol-gel technique.The samples were characterized by X-ray diffraction,SEM and VSM.A structure transition of La0.7Sr0.3-xKxMnO3 with x increasing from tetrahedron to monoclinic was observed.The morphology of La0.7Sr0.3-xKxMnO3 is inhomo-geneous ball with diameters of 100~500 nm.The Curie temperature and magnetization of La0.7Sr0.3-xKxMnO3 decrease with x increasing.When x=0.2,Tc (309 K) is near room temperature.This is the result of the Mn4+/Mn3+ ratio increasing,average ionic radii increasing and ionic mismatch enhancement.La0.7Sr0.1K0.2-MnO3 shows a larger magnetic entropy of ΔSM=3.28 J/(Kg·K) near Tc due to strong magnetism and crystal lattice coupling effect in doped perovskite oxides.
2008, 25(7): 829-833
Abstract:
The electrochemical behavior of amlodipine (AM) at the multi-wall carbon nanotube (MWCNT) modified glassy carbon electrode (GCE) was investigated by cyclic voltammetry (CV),linear sweep volta-mmetry (LSV) and differential pulse voltammetry (DPV).The experimental parameters were optimized,and a direct electroanalytical method for determining AM was developed.The oxidation peak current of AM was enhanced significantly at the MWCNT modified GCE,in contrast to that at the bare GCE.Under the optimized experimental conditions,the oxidation peak current varied linearly with the concentration of AM over a range from 1.0×10-7 to 7.5×10-5 mol/L with a detection limit of 4.0×10-8 mol/L.The relative standard deviation (RSD) for 1.0×10-5 mol/L AM was approximately 4.2% (n=10).AM in pharmaceutical formulations was determined by method.
The electrochemical behavior of amlodipine (AM) at the multi-wall carbon nanotube (MWCNT) modified glassy carbon electrode (GCE) was investigated by cyclic voltammetry (CV),linear sweep volta-mmetry (LSV) and differential pulse voltammetry (DPV).The experimental parameters were optimized,and a direct electroanalytical method for determining AM was developed.The oxidation peak current of AM was enhanced significantly at the MWCNT modified GCE,in contrast to that at the bare GCE.Under the optimized experimental conditions,the oxidation peak current varied linearly with the concentration of AM over a range from 1.0×10-7 to 7.5×10-5 mol/L with a detection limit of 4.0×10-8 mol/L.The relative standard deviation (RSD) for 1.0×10-5 mol/L AM was approximately 4.2% (n=10).AM in pharmaceutical formulations was determined by method.
Synthesis and Surface Properties of N-[3-polyether-3-dimethylamino propyl]Perfluorooctanesulfonamide
2008, 25(7): 834-837
Abstract:
With perfluorooctanesulfonyl fluoride as raw material,a polyether quaternary ammonium salt cationic fluorocarbon surfactant was synthesized.Structures of the surfactant and its intermediates were characterized by IR and 1H NMR spectroscopies.The surface tension of the surfactant in aqueous solution was measured,the lowest surface tension was 18.8 mN/m,and its critical micell concentration (CMC) was 54 mmol/L.This indicates it has a better surface activity than that of common surfactants.
With perfluorooctanesulfonyl fluoride as raw material,a polyether quaternary ammonium salt cationic fluorocarbon surfactant was synthesized.Structures of the surfactant and its intermediates were characterized by IR and 1H NMR spectroscopies.The surface tension of the surfactant in aqueous solution was measured,the lowest surface tension was 18.8 mN/m,and its critical micell concentration (CMC) was 54 mmol/L.This indicates it has a better surface activity than that of common surfactants.
2008, 25(7): 838-842
Abstract:
SnO2 was synthesized by sol-gel method,and Vulcan XC-72 carbon was used as a carrier to form SnO2-C(ω(SnO2)=20%) electro-catalyst.X-ray diffraction (XRD) indicated that the phase of SnO2 belonged to rutile,and the particle size was ca.100 nm by scanning electron microscopy (SEM).Cyclic voltammetric (CV) results indicated that the activity of the catalyst on Sb doped SnO2-C/Ti electrode was higher than that on SnO2-C/Ti electrode especially in alkali solution with the oxidation current rised from 8×10-3 mA to 1.5×10-2 mA.Electrochemical impedance spectroscopy (EIS) measurement indicated that a film was formed on the surface of electrode,and the composition of the film changed with different applied potentials.
SnO2 was synthesized by sol-gel method,and Vulcan XC-72 carbon was used as a carrier to form SnO2-C(ω(SnO2)=20%) electro-catalyst.X-ray diffraction (XRD) indicated that the phase of SnO2 belonged to rutile,and the particle size was ca.100 nm by scanning electron microscopy (SEM).Cyclic voltammetric (CV) results indicated that the activity of the catalyst on Sb doped SnO2-C/Ti electrode was higher than that on SnO2-C/Ti electrode especially in alkali solution with the oxidation current rised from 8×10-3 mA to 1.5×10-2 mA.Electrochemical impedance spectroscopy (EIS) measurement indicated that a film was formed on the surface of electrode,and the composition of the film changed with different applied potentials.
2008, 25(7): 843-847
Abstract:
An efficient and convenient method for the synthesis of 2-amino-2-chromenes has been achieved through the ‘one-pot’ three-component condensation reaction of aromatic aldehydes,malononitrile and α- or β-naphthol in the presence of 10% mol of functionalized ionic liquid,2-hydroxyethlammonium acetate ([H3N+CH2CH2OH][CH3CO2-]),in water at 100℃ to afford the corresponding compounds in 89%~98% yields.The present protocol offers several advantages,including simple work-up procedure,high yields,short reaction time and moreover the ionic liquid reusability and benignity to the environment.For the reaction of benzaldehyde,malononitrile and α-naphthol,the ionic liquid can be recycled at least 3 times without the significant loss of activity.A possible reaction mechanism is proposed under the reaction conditions.
An efficient and convenient method for the synthesis of 2-amino-2-chromenes has been achieved through the ‘one-pot’ three-component condensation reaction of aromatic aldehydes,malononitrile and α- or β-naphthol in the presence of 10% mol of functionalized ionic liquid,2-hydroxyethlammonium acetate ([H3N+CH2CH2OH][CH3CO2-]),in water at 100℃ to afford the corresponding compounds in 89%~98% yields.The present protocol offers several advantages,including simple work-up procedure,high yields,short reaction time and moreover the ionic liquid reusability and benignity to the environment.For the reaction of benzaldehyde,malononitrile and α-naphthol,the ionic liquid can be recycled at least 3 times without the significant loss of activity.A possible reaction mechanism is proposed under the reaction conditions.
2008, 25(7): 848-853
Abstract:
Traditionally the synthesis of metallodeuteroporphyrins-Ⅸ-dimethylester is carried out in a system of CH2Cl2/CH3OH,but the yields of nickel (Ⅱ) and zinc (Ⅱ) deuteroporphyrins in the system are very low,both less than 50%.In this paper,the effects of solvent,metal-salt,reaction temperature and reaction time on the synthesis of metal-porphyrins were investigated.Cu(Ⅱ),Co(Ⅱ),Ni(Ⅱ) and Zn(Ⅱ) metallodeuteroporphyrin-Ⅸ-dimethylesters and their metal-3-acetyldeuteroporphyrin-Ⅸ-dimethylesters were synthesized and characterized.The yields of Ni(Ⅱ) and Zn(Ⅱ) metallodeuteroporphyrin-Ⅸ-dimethylesters were increased greatly to about 98% when DMF was used as the solvent;at the same time,the reaction time decreased from 2 h in the CH2Cl2/CH3OH system to 0.5 h and the amount of solvent decreased from 150 mL to 20 mL.And the purification of products was carried out simply by reclaiming solvent under reduced pressure first and then removing inorganic salts by washing the residue with water instead of by extraction method which consumes large amount of solvent.
Traditionally the synthesis of metallodeuteroporphyrins-Ⅸ-dimethylester is carried out in a system of CH2Cl2/CH3OH,but the yields of nickel (Ⅱ) and zinc (Ⅱ) deuteroporphyrins in the system are very low,both less than 50%.In this paper,the effects of solvent,metal-salt,reaction temperature and reaction time on the synthesis of metal-porphyrins were investigated.Cu(Ⅱ),Co(Ⅱ),Ni(Ⅱ) and Zn(Ⅱ) metallodeuteroporphyrin-Ⅸ-dimethylesters and their metal-3-acetyldeuteroporphyrin-Ⅸ-dimethylesters were synthesized and characterized.The yields of Ni(Ⅱ) and Zn(Ⅱ) metallodeuteroporphyrin-Ⅸ-dimethylesters were increased greatly to about 98% when DMF was used as the solvent;at the same time,the reaction time decreased from 2 h in the CH2Cl2/CH3OH system to 0.5 h and the amount of solvent decreased from 150 mL to 20 mL.And the purification of products was carried out simply by reclaiming solvent under reduced pressure first and then removing inorganic salts by washing the residue with water instead of by extraction method which consumes large amount of solvent.
2008, 25(7): 854-858
Abstract:
Clew nano-sized NaY zeolite was synthesized from metakaolin by adding alcohol to the hydrothe-rmal synthesis system.Its structure was characterized by XRD,SEM,TEM,HREM,and its physicochemical properties and catalytic characteristics were studied.The results show that the size of the product with clew morphology is 100~150 nm,relative crystallinity 59.61%,and Si/Al ratio 5.02.Compared with conven-tional NaY zeolite,this kind of nano-sized zeolite has a larger surface area and mesopore volume,better thermal and hydrothermal stability,higher cracking activity,higher gasoline selectivity,lower coke and dry gas selectivity.So it has good industry application prospects.
Clew nano-sized NaY zeolite was synthesized from metakaolin by adding alcohol to the hydrothe-rmal synthesis system.Its structure was characterized by XRD,SEM,TEM,HREM,and its physicochemical properties and catalytic characteristics were studied.The results show that the size of the product with clew morphology is 100~150 nm,relative crystallinity 59.61%,and Si/Al ratio 5.02.Compared with conven-tional NaY zeolite,this kind of nano-sized zeolite has a larger surface area and mesopore volume,better thermal and hydrothermal stability,higher cracking activity,higher gasoline selectivity,lower coke and dry gas selectivity.So it has good industry application prospects.
2008, 25(7): 859-861
Abstract:
α-Amino phosphonates were one-pot synthesized from carbonyl compound,amines,diethylphosphite with the inexpensive,nontoxic and readily available sulfamic acid as Lewis acid catalyst.The syntheses were carried out under solvent-free conditions at ambient temperature.Seven products were given and the structures of target compounds were confirmed by 1H NMR.The overall yields of the products were all above 80%.This method was mild,simple,safe and easily manipulated.After the reaction was completed,the catalyst of sulfamic acid could be recovered after simple treatment and could be used for next cycle.
α-Amino phosphonates were one-pot synthesized from carbonyl compound,amines,diethylphosphite with the inexpensive,nontoxic and readily available sulfamic acid as Lewis acid catalyst.The syntheses were carried out under solvent-free conditions at ambient temperature.Seven products were given and the structures of target compounds were confirmed by 1H NMR.The overall yields of the products were all above 80%.This method was mild,simple,safe and easily manipulated.After the reaction was completed,the catalyst of sulfamic acid could be recovered after simple treatment and could be used for next cycle.
2008, 25(7): 862-864
Abstract:
Eleven new aryloxyacetyl ureas were synthesized by the reaction of 2-amino-1,3,4-thiodiazole with aryloxyacetyl isocynates in yields of 50.2%~68.7%.Their structures were confirmed by IR,1H NMR and elemental analysis.The preliminary biological activity tests show that some target compounds have good activities as plant growth regulator.Compounds 2d,2e,2k have a relatively good activity of auxin and the promoting rates of them are 40.1%,35.5% and 28.8% respectively.
Eleven new aryloxyacetyl ureas were synthesized by the reaction of 2-amino-1,3,4-thiodiazole with aryloxyacetyl isocynates in yields of 50.2%~68.7%.Their structures were confirmed by IR,1H NMR and elemental analysis.The preliminary biological activity tests show that some target compounds have good activities as plant growth regulator.Compounds 2d,2e,2k have a relatively good activity of auxin and the promoting rates of them are 40.1%,35.5% and 28.8% respectively.
2008, 25(7): 865-867
Abstract:
The system of viscoelastic surfactant (VES-Y) was formed with potassium oleate and potassium chloride,and the viscoelastic gel (VES-G) was formed by the addition of a crosslinking agent (N,N'-methylene diacrylamide) and an initiator (sodium supersulphate) to VES-Y and heated for 24 h at 60℃ under nitrogen.The properties of VES-Y and VES-G were evaluated in terms of temperature tolerance,shear thinning,sensitivity to hydrocarbon,breakdown and damage to permeability.The results showed that VES-G was less sensitive to hydrocarbon and had an improvement on its temperature tolerance and shear thinning.VES-Y and VES-G both exhibited the same breakdown propertities.In addition,VES-G showed no damage regained permeability over 99 percent after breakdown by core flow experiments.
The system of viscoelastic surfactant (VES-Y) was formed with potassium oleate and potassium chloride,and the viscoelastic gel (VES-G) was formed by the addition of a crosslinking agent (N,N'-methylene diacrylamide) and an initiator (sodium supersulphate) to VES-Y and heated for 24 h at 60℃ under nitrogen.The properties of VES-Y and VES-G were evaluated in terms of temperature tolerance,shear thinning,sensitivity to hydrocarbon,breakdown and damage to permeability.The results showed that VES-G was less sensitive to hydrocarbon and had an improvement on its temperature tolerance and shear thinning.VES-Y and VES-G both exhibited the same breakdown propertities.In addition,VES-G showed no damage regained permeability over 99 percent after breakdown by core flow experiments.
2008, 25(7): 868-870
Abstract:
The electrode modified by multilayer films of polyoxometalate (POM) K17[Ce(P2Mo17O61)2]and polyelectrolyte by means of layer-by-layer assembly was prepared and investigated.The stable multilayer films were assembled by alternate adsorption of negatively charged POM and positively charged polyelectrolyte from their aqueous dispersions.The proposed novel electrode exhibited a good electrocatalytic oxidation on I- anions in solution.Based on this,flow injection amperometry was proposed for the determination of iodide.By the flow injection amperometry (FIA),there existed a good linear relationship between the concentration of iodide and the response current in a range of 1×10-5 mol/L and 1×10-3 mol/L,and the detection limit was 5×10-5 mol/L.The method has been successfully applied to the determination of iodide in dry edible seaweed.The concentrations of iodide measured by this method are in good agreement with those obtained by spectrophotometric method.
The electrode modified by multilayer films of polyoxometalate (POM) K17[Ce(P2Mo17O61)2]and polyelectrolyte by means of layer-by-layer assembly was prepared and investigated.The stable multilayer films were assembled by alternate adsorption of negatively charged POM and positively charged polyelectrolyte from their aqueous dispersions.The proposed novel electrode exhibited a good electrocatalytic oxidation on I- anions in solution.Based on this,flow injection amperometry was proposed for the determination of iodide.By the flow injection amperometry (FIA),there existed a good linear relationship between the concentration of iodide and the response current in a range of 1×10-5 mol/L and 1×10-3 mol/L,and the detection limit was 5×10-5 mol/L.The method has been successfully applied to the determination of iodide in dry edible seaweed.The concentrations of iodide measured by this method are in good agreement with those obtained by spectrophotometric method.
2008, 25(7): 871-873
Abstract:
9-Hydroxyl-(E)-2-decenoic acid and 9-carbonyl-(E)-2-decenoic acid are the main components of queen honeybee pheromones.9-Carbonyl-(E)-2-decenoic acid was synthesized from 1-(phenylsulfonyl)-2-acetone and 5-bromo-ethyl valerate in five steps,which was enzymatic reduced with bakers' yeast to give S-9-hydroxyl-(E)-2-decenoic acid.The total yield was about 28%.The materials used were easy to obtain,and the reaction conditions were mild,and the yield satisfactory.
9-Hydroxyl-(E)-2-decenoic acid and 9-carbonyl-(E)-2-decenoic acid are the main components of queen honeybee pheromones.9-Carbonyl-(E)-2-decenoic acid was synthesized from 1-(phenylsulfonyl)-2-acetone and 5-bromo-ethyl valerate in five steps,which was enzymatic reduced with bakers' yeast to give S-9-hydroxyl-(E)-2-decenoic acid.The total yield was about 28%.The materials used were easy to obtain,and the reaction conditions were mild,and the yield satisfactory.
2008, 25(7): 874-876
Abstract:
Mononitration of toluene with nitric acid in the presence of sodium bisulfate was studied.The results show that when the nitrated reaction temperature was controlled at 45℃,and the nitrated reaction time was 60 min,nitration of toluene with 95% nitric acid as nitrating reagent in the presence of acetic anhydride and 1.8 g sodium bisulfate catalyst exhibited a high regioselectivity,with ortho-para isomer ratio up to 1.09 in product distribution of toluene nitration,greatly below ortho-para isomer ratio of 1.67 in the product distribution of toluene nitration with sulfonitric acid as catalyst,and gave a yield of 99.9%.The catalyst could be reutilized up to five times with little decrease in activity.It is a kind of prowising nitrated reaction catalyst to replace sulfonitric acid,and has a vast value of industrialization exploitation.
Mononitration of toluene with nitric acid in the presence of sodium bisulfate was studied.The results show that when the nitrated reaction temperature was controlled at 45℃,and the nitrated reaction time was 60 min,nitration of toluene with 95% nitric acid as nitrating reagent in the presence of acetic anhydride and 1.8 g sodium bisulfate catalyst exhibited a high regioselectivity,with ortho-para isomer ratio up to 1.09 in product distribution of toluene nitration,greatly below ortho-para isomer ratio of 1.67 in the product distribution of toluene nitration with sulfonitric acid as catalyst,and gave a yield of 99.9%.The catalyst could be reutilized up to five times with little decrease in activity.It is a kind of prowising nitrated reaction catalyst to replace sulfonitric acid,and has a vast value of industrialization exploitation.
