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2009 Volume 26 Issue 12
2009, 26(6): 1377-1385
Abstract:
A series of oligoaniline-modified mono-and bis-nuclear iron(Ⅱ) complexes were synthesized successfully,and their spectroscopic and electrochemical properties were studied.The metal-to-ligand charge-transfer transition(1MLCT) bands of the complexes with oligoaniline groups are considerably red-shifted(converge to 594 nm with increasing chain length) and their intensities become much more intense(approximately 5 times),compared with that of the reported complex [Fe(TPY)2]2+.All the complexes show multiplicate redox processes based on the [Fe(TPY)2]2+ core and oligoaniline unit.Their electrochemical behaviors can be modulated by changing the chain length and the substituent group in the oligoaniline unit.
A series of oligoaniline-modified mono-and bis-nuclear iron(Ⅱ) complexes were synthesized successfully,and their spectroscopic and electrochemical properties were studied.The metal-to-ligand charge-transfer transition(1MLCT) bands of the complexes with oligoaniline groups are considerably red-shifted(converge to 594 nm with increasing chain length) and their intensities become much more intense(approximately 5 times),compared with that of the reported complex [Fe(TPY)2]2+.All the complexes show multiplicate redox processes based on the [Fe(TPY)2]2+ core and oligoaniline unit.Their electrochemical behaviors can be modulated by changing the chain length and the substituent group in the oligoaniline unit.
2009, 26(6): 1386-1390
Abstract:
Seven 5-bromo-2-hydroxy benzoyl substituted aromatic aldehyde hydrazones were synthesized with methyl salicylate as raw materials via bromination,hydrazination and condensation reactions,respectively.Three novel compounds were reported.The structures of all the synthesized compounds were confirmed by 1H NMR,IR,mass spectra and elemental analysis.The result of preliminary bioassay shows that the title compounds have obvious selective antibacterial activities to different classificatory bacterium at 0.05%(mass concentration),and have 100% inhibitory rate on Monilia albican and Bacillus subtilis.They will be a kind of potential antibacterial compounds against fungus and Gram-positive bacteria.5-Bromo-2-hydroxyphenyl-3',5'-dibromo-o-hydroxyphenyl substituted aromatic aldehyde hydrazone has the same antibacterial activity as triclosan.The analysis of structure activity shows that the antibacterial activities are related to the kind of Ar-ring and its substituent groups.The antibacterial activities are reduced by electron-donating groups,such as o-,p-OH,—OCH3 of Ar-ring,however,they are enhanced by the m-substituted halogen groups of Ar-ring.
Seven 5-bromo-2-hydroxy benzoyl substituted aromatic aldehyde hydrazones were synthesized with methyl salicylate as raw materials via bromination,hydrazination and condensation reactions,respectively.Three novel compounds were reported.The structures of all the synthesized compounds were confirmed by 1H NMR,IR,mass spectra and elemental analysis.The result of preliminary bioassay shows that the title compounds have obvious selective antibacterial activities to different classificatory bacterium at 0.05%(mass concentration),and have 100% inhibitory rate on Monilia albican and Bacillus subtilis.They will be a kind of potential antibacterial compounds against fungus and Gram-positive bacteria.5-Bromo-2-hydroxyphenyl-3',5'-dibromo-o-hydroxyphenyl substituted aromatic aldehyde hydrazone has the same antibacterial activity as triclosan.The analysis of structure activity shows that the antibacterial activities are related to the kind of Ar-ring and its substituent groups.The antibacterial activities are reduced by electron-donating groups,such as o-,p-OH,—OCH3 of Ar-ring,however,they are enhanced by the m-substituted halogen groups of Ar-ring.
2009, 26(6): 1391-1394
Abstract:
Using emulsification process and ion association method,gelatin(Gel)/β-tricalcium phosphate(β-TCP) porous composite microspheres were fabricated.The size of the composite microspheres was adjusted by controlling the rate of stirring in the reaction.From the SEM and optical microscopy images,it was found that the size of the composite microspheres arranged from 20 to 40 μm,and the TCP embedded was about 200 nm,and porous structure was formed within the microspheres.When the ratio of m(TCP):m(Gel) was more than 0.4:1,large quantities of petal-like crystal were formed on the surface of the composite microspheres.It was assumed that shaped crystal was formed by TCP dissolved in the reactive solution and inductive re-crystallization by gelatin molecule.IR and XRD show that these composite microspheres contained the structure similar to the natural bone and the chemical bonds existed between the gelatin and TCP.DSC-TGA image illustrates that 90% TCP was embedded inside the gelatin spheres through the emulsion process.The prepared-composite microspheres supplied an excellent carrier for loading and releasing various pharmaceuticals and promoting bone growth factor.
Using emulsification process and ion association method,gelatin(Gel)/β-tricalcium phosphate(β-TCP) porous composite microspheres were fabricated.The size of the composite microspheres was adjusted by controlling the rate of stirring in the reaction.From the SEM and optical microscopy images,it was found that the size of the composite microspheres arranged from 20 to 40 μm,and the TCP embedded was about 200 nm,and porous structure was formed within the microspheres.When the ratio of m(TCP):m(Gel) was more than 0.4:1,large quantities of petal-like crystal were formed on the surface of the composite microspheres.It was assumed that shaped crystal was formed by TCP dissolved in the reactive solution and inductive re-crystallization by gelatin molecule.IR and XRD show that these composite microspheres contained the structure similar to the natural bone and the chemical bonds existed between the gelatin and TCP.DSC-TGA image illustrates that 90% TCP was embedded inside the gelatin spheres through the emulsion process.The prepared-composite microspheres supplied an excellent carrier for loading and releasing various pharmaceuticals and promoting bone growth factor.
2009, 26(6): 1395-1398
Abstract:
With methyl-S-(-)-lactate,S-(-)-α phenylethyl alcohol,(S)-(+)-2-butanol as the chiral pool,new chiral unsaturated esters were synthesized under the catalysis of N,N'-dicyclohexyl carbodimide(DCC) and 4-dimethylaminopyridines.The products were characterized by means of infrared,NMR and elemental analysis.A chiral stationary phase was obtained by grafting these monomers to polysiloxane.
With methyl-S-(-)-lactate,S-(-)-α phenylethyl alcohol,(S)-(+)-2-butanol as the chiral pool,new chiral unsaturated esters were synthesized under the catalysis of N,N'-dicyclohexyl carbodimide(DCC) and 4-dimethylaminopyridines.The products were characterized by means of infrared,NMR and elemental analysis.A chiral stationary phase was obtained by grafting these monomers to polysiloxane.
2009, 26(6): 1399-1403
Abstract:
Biomorphic porous Si/SiC ceramics were prepared by liquid silicon infiltration-reaction and subsequent removal of residual Si.The microstructure morphology and component analysis of the cellular Si/SiC were investigated by means of scanning electron microscopy and X-ray diffraction.The porosity and distribution of the pore diameter of porous Si/SiC were determined by mercury intrusion method.Results show that the resulting porous ceramic is composed of major crystal phase β-SiC and secondary phase residual free Si.The ceramic composite maintained the original morphology of the wood and exhibited a porosity of 16%~32% by controlling the for Si removal time.The Archimedes and three-point bending methods were used to test the apparent porosity and bending strength of porous SiC ceramic.The influences of the Si removal time on the final phase composition and mechanic properties of the formed biomorphic Si/SiC ceramic composite were analyzed.The formation mechanism of SiC was also discussed.
Biomorphic porous Si/SiC ceramics were prepared by liquid silicon infiltration-reaction and subsequent removal of residual Si.The microstructure morphology and component analysis of the cellular Si/SiC were investigated by means of scanning electron microscopy and X-ray diffraction.The porosity and distribution of the pore diameter of porous Si/SiC were determined by mercury intrusion method.Results show that the resulting porous ceramic is composed of major crystal phase β-SiC and secondary phase residual free Si.The ceramic composite maintained the original morphology of the wood and exhibited a porosity of 16%~32% by controlling the for Si removal time.The Archimedes and three-point bending methods were used to test the apparent porosity and bending strength of porous SiC ceramic.The influences of the Si removal time on the final phase composition and mechanic properties of the formed biomorphic Si/SiC ceramic composite were analyzed.The formation mechanism of SiC was also discussed.
2009, 26(6): 1404-1408
Abstract:
Al-MCM-41 mesoporous sieves were synthesized by using Na2SiO3 as silica source,Al2(SO4)3 as aluminum source,and cetyltrimethylammonium bromide(CTAB) as template under hydrothermal condition.The Al-MCM-41 mesoporous sieves were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and infrared spectroscopy(IR).The synthesis of diphenylethane over Al-MCM-41 catalyst and its catalytic performance were investigated.The results show that the optimal conditions were the mass percent of catalyst was 1% of the feed stock;molar ratio of xylene to styrene was 7.5:1;reaction temperature was 140 ℃ and reaction time 3 h.The yield of diphenylethane under such conditions was about 87.1%,which was 17% higher than the yield when traditional sulfuric acid was used as catalyst.The results show that Al-MCM-41 is a promising solid acid catalyst for the synthesis of diphenylethylane instead of liquid acid.
Al-MCM-41 mesoporous sieves were synthesized by using Na2SiO3 as silica source,Al2(SO4)3 as aluminum source,and cetyltrimethylammonium bromide(CTAB) as template under hydrothermal condition.The Al-MCM-41 mesoporous sieves were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and infrared spectroscopy(IR).The synthesis of diphenylethane over Al-MCM-41 catalyst and its catalytic performance were investigated.The results show that the optimal conditions were the mass percent of catalyst was 1% of the feed stock;molar ratio of xylene to styrene was 7.5:1;reaction temperature was 140 ℃ and reaction time 3 h.The yield of diphenylethane under such conditions was about 87.1%,which was 17% higher than the yield when traditional sulfuric acid was used as catalyst.The results show that Al-MCM-41 is a promising solid acid catalyst for the synthesis of diphenylethylane instead of liquid acid.
2009, 26(6): 1409-1413
Abstract:
The structural effect of benzofuranone derivatives on their ability to scavenge 2,2-diphenyl-1-picrylhydrazl(DPPH) was studied via radical colorimetry.The results show that the changes of methyl and tert-butyl groups on 5 and 7 positions of mother benzene ring of benzofuranone and the presence of strong electron-donating substituent in substituted benzene ring have little influences on the ability of benzofuranone derivatives scavenging DPPH.Substituent of 2'-position prevents the attack of benzofuranone toward radicals,which weak the scavenging ability of benzofuranone derivatives for DPPH.And the scavenging ability of benzofuranone for DPPH will be weakened further when the substituent of 2'-position is without reactive hydrogen and can form hydrogen bonds with 3-reactive hydrogen.When the substituent of 2'-position is with reactive hydrogen,the reactive hydrogen will be activated due to the formation of hydrogen bonding between substituted group with 3-reactive hydrogen,and the position hindrance will be generated in a great extent.
The structural effect of benzofuranone derivatives on their ability to scavenge 2,2-diphenyl-1-picrylhydrazl(DPPH) was studied via radical colorimetry.The results show that the changes of methyl and tert-butyl groups on 5 and 7 positions of mother benzene ring of benzofuranone and the presence of strong electron-donating substituent in substituted benzene ring have little influences on the ability of benzofuranone derivatives scavenging DPPH.Substituent of 2'-position prevents the attack of benzofuranone toward radicals,which weak the scavenging ability of benzofuranone derivatives for DPPH.And the scavenging ability of benzofuranone for DPPH will be weakened further when the substituent of 2'-position is without reactive hydrogen and can form hydrogen bonds with 3-reactive hydrogen.When the substituent of 2'-position is with reactive hydrogen,the reactive hydrogen will be activated due to the formation of hydrogen bonding between substituted group with 3-reactive hydrogen,and the position hindrance will be generated in a great extent.
2009, 26(6): 1414-1417
Abstract:
A kind of new surface sizing agent was prepared from polystyrene-acrylate(PSB) emulsion modified with montmorillonite(MMT).The effects of different processes on emulsion properties were studied.The structure of the nanocomposite emulsion was characterized by X-ray diffraction(XRD) and transmission electron microscopy(TEM).The effects of PSB/MMT nanocomposite emulsion as surface size on physical properties and water resistance of paper were studied.The result shows that montmorillonite in the emulsion exfoliated,and the dispersion of MMT reached nano-level.When sizing agent was about 10% of starch,the increase of paper's sizing value,stiffness and ring crush were 1.8 times,45.5% and 44%,respectively.
A kind of new surface sizing agent was prepared from polystyrene-acrylate(PSB) emulsion modified with montmorillonite(MMT).The effects of different processes on emulsion properties were studied.The structure of the nanocomposite emulsion was characterized by X-ray diffraction(XRD) and transmission electron microscopy(TEM).The effects of PSB/MMT nanocomposite emulsion as surface size on physical properties and water resistance of paper were studied.The result shows that montmorillonite in the emulsion exfoliated,and the dispersion of MMT reached nano-level.When sizing agent was about 10% of starch,the increase of paper's sizing value,stiffness and ring crush were 1.8 times,45.5% and 44%,respectively.
2009, 26(6): 1418-1421
Abstract:
Polyethylene glycol with reactive chain ends was synthesized from maleic anhydride and polyethylene glycol and used as a modifier for the epoxy acrylate resin.The product was characterized by FTIR and 1H NMR.The influence of reaction temperature and time on the reaction and properties of the reactive polyethylene glycol is discussed.When the molar ratio of the maleic anhydride and polyethylene glycol was 2.1:1,the conversion rate of the reaction reached 95.2% at 75 ℃ for 60 min.The cured sample of reactive polyethylene glycol with epoxy acrylate resin was characterized by FTIR.The results indicate that the reactive polyethylene glycol participated in the curing reaction of the epoxy acrylate resin,forming soft segments in the network,which significantly increased the impact strength of the epoxy acrylate resin.
Polyethylene glycol with reactive chain ends was synthesized from maleic anhydride and polyethylene glycol and used as a modifier for the epoxy acrylate resin.The product was characterized by FTIR and 1H NMR.The influence of reaction temperature and time on the reaction and properties of the reactive polyethylene glycol is discussed.When the molar ratio of the maleic anhydride and polyethylene glycol was 2.1:1,the conversion rate of the reaction reached 95.2% at 75 ℃ for 60 min.The cured sample of reactive polyethylene glycol with epoxy acrylate resin was characterized by FTIR.The results indicate that the reactive polyethylene glycol participated in the curing reaction of the epoxy acrylate resin,forming soft segments in the network,which significantly increased the impact strength of the epoxy acrylate resin.
2009, 26(6): 1422-1427
Abstract:
A new series of Gemini imidazoline quaternary ammonium salts as corrosion inhibitor(S-HSJ) was synthesized.The corrosion inhibition performance,the influences of carbon chain length in lipophilic structure,corrosion time and corrosion inhibitor concentration were investigated comprehensively.The experiments for copper,brass,aluminum and tinplate were conducted in 5% hydrochloric acid solutions with the help of mass loss method.The results show that the inhibition effects of the series of S-HSJ corrosion inhibitor are better than those of traditional quaternary ammonium salts and benzotriazole for several metals.The inhibition efficiency of S-HSJ-16 can reach 94%~99% when an amount of 0.1% such an inhibitor was added.The complex inhibition ability with anion surfactant shows an obviously synergistic effect.
A new series of Gemini imidazoline quaternary ammonium salts as corrosion inhibitor(S-HSJ) was synthesized.The corrosion inhibition performance,the influences of carbon chain length in lipophilic structure,corrosion time and corrosion inhibitor concentration were investigated comprehensively.The experiments for copper,brass,aluminum and tinplate were conducted in 5% hydrochloric acid solutions with the help of mass loss method.The results show that the inhibition effects of the series of S-HSJ corrosion inhibitor are better than those of traditional quaternary ammonium salts and benzotriazole for several metals.The inhibition efficiency of S-HSJ-16 can reach 94%~99% when an amount of 0.1% such an inhibitor was added.The complex inhibition ability with anion surfactant shows an obviously synergistic effect.
2009, 26(6): 1428-1434
Abstract:
The sulfonic group functionalized ionic liquid—1-H-3-(3-sulfonic acid)propylimidazolium chloride was immobilized on micro-ball silica-gel with γ-chloropropyltrimethoxysilane as coupling agent to obtain the silica-gel immobilized ionic liquid(IL3).IL3 was characterized by SEM,FTIR,DSC-TG,13C NMR,BET,and acidity measurement.Its catalytic performance in the synthesis of 5-hydroxymethylfurfural(HMF) from fructose dehydration was investigated.The results indicate that 1-H-3-(3-sulfonic acid)propylimidazolium chloride could be immobilized on micro-ball silica-gel surface by chemical bonds,and IL3 is a good catalyst for the HMF synthesis from fructose dehydration.The yield of HMF was up to 82.1% with 45.4% loading of IL3 as the catalyst and ethylene glycol monomethyl ether(EGME) as solvent at 115 ℃ over 5 h.After IL3 reused four times,the yield of HMF decreased from 82.1% to 53.0%.
The sulfonic group functionalized ionic liquid—1-H-3-(3-sulfonic acid)propylimidazolium chloride was immobilized on micro-ball silica-gel with γ-chloropropyltrimethoxysilane as coupling agent to obtain the silica-gel immobilized ionic liquid(IL3).IL3 was characterized by SEM,FTIR,DSC-TG,13C NMR,BET,and acidity measurement.Its catalytic performance in the synthesis of 5-hydroxymethylfurfural(HMF) from fructose dehydration was investigated.The results indicate that 1-H-3-(3-sulfonic acid)propylimidazolium chloride could be immobilized on micro-ball silica-gel surface by chemical bonds,and IL3 is a good catalyst for the HMF synthesis from fructose dehydration.The yield of HMF was up to 82.1% with 45.4% loading of IL3 as the catalyst and ethylene glycol monomethyl ether(EGME) as solvent at 115 ℃ over 5 h.After IL3 reused four times,the yield of HMF decreased from 82.1% to 53.0%.
2009, 26(6): 1435-1438
Abstract:
One mixed-ligand complex of [Zn(tpa)(tripy)]n·nH2O(tpa=terephthalate,tripy=4'-(4-methyoxyphenyl)-2,2':6',2''-terpyridine)] was synthesized and characterized by IR,elemental analysis and thermo-gravimetric analysis.The crystal structure of the product was established by single-crystal X-ray diffraction.It is a monoclinic crystal with space group P21/c.a=0.855 0(2) nm,b=2.825 0(6) nm,c=1.096 0(2) nm,β=107.14(3)°,V=2.529 7(9) nm3,Z=4,Dc=1.541 g/cm3,Mr=586.88,F(000)=1 208,R1=0.100 6,ωR2=0.264 8.The complex consists of one-dimensional Zig-zag chain.Compared with the ligand,the complex exhibits intense photoluminescence.
One mixed-ligand complex of [Zn(tpa)(tripy)]n·nH2O(tpa=terephthalate,tripy=4'-(4-methyoxyphenyl)-2,2':6',2''-terpyridine)] was synthesized and characterized by IR,elemental analysis and thermo-gravimetric analysis.The crystal structure of the product was established by single-crystal X-ray diffraction.It is a monoclinic crystal with space group P21/c.a=0.855 0(2) nm,b=2.825 0(6) nm,c=1.096 0(2) nm,β=107.14(3)°,V=2.529 7(9) nm3,Z=4,Dc=1.541 g/cm3,Mr=586.88,F(000)=1 208,R1=0.100 6,ωR2=0.264 8.The complex consists of one-dimensional Zig-zag chain.Compared with the ligand,the complex exhibits intense photoluminescence.
2009, 26(6): 1439-1444
Abstract:
Three Cr(Ⅲ) coordination complexes,[Cr(en)2ox][Cr(en)(ox)2]·2H2O(1),[Co(NH2NHCSNH2)3][Cr(ox)3]·7H2O(2),and Cr(acac)3(3),were synthesized by the groovy method(en=ethylenediamine,ox=oxalic acid,acac=acetylacetone).The crystal structures of the complexes were determined by X-ray single crystal diffraction,and the complexes were characterized by UV-Vis and surface photovoltage spectrum(SPS).Surface photovoltage performance of the three complexes were emphatically studied,and compared with their UV-Vis spectra.The results of surface photovoltage spectra of complexes 1~3 indicate that the complexes exhibit better surface photovoltage responses in a range of 300~600 nm,and the determined surface photovoltage and the UV-Vis spectra present comparatively well corresponding relation.
Three Cr(Ⅲ) coordination complexes,[Cr(en)2ox][Cr(en)(ox)2]·2H2O(1),[Co(NH2NHCSNH2)3][Cr(ox)3]·7H2O(2),and Cr(acac)3(3),were synthesized by the groovy method(en=ethylenediamine,ox=oxalic acid,acac=acetylacetone).The crystal structures of the complexes were determined by X-ray single crystal diffraction,and the complexes were characterized by UV-Vis and surface photovoltage spectrum(SPS).Surface photovoltage performance of the three complexes were emphatically studied,and compared with their UV-Vis spectra.The results of surface photovoltage spectra of complexes 1~3 indicate that the complexes exhibit better surface photovoltage responses in a range of 300~600 nm,and the determined surface photovoltage and the UV-Vis spectra present comparatively well corresponding relation.
2009, 26(6): 1445-1449
Abstract:
Bentonite reacted with NaOH at a high temperature leading to a very reactive starting material for zeolite synthesis.Zeolite 4A was synthesized by hydrothermal method with natural bentonite as raw material.The effects of activation temperature,molar ratio of SiO2/Al2O3,molar ratio of Na2O/SiO2,molar ratio of H2O/Na2O on the properties of the products were investigated by means of XRD,SEM and calcium ion exchange capacity.The results show that the best activation temperature was 600 ℃.After activation of the materials,the composition of the mixed compound was regulated as(molar ratio):SiO2/Al2O3 =1.5,Na2O/SiO2=3 and H2O/Na2O=50,then crystallization was carried out at 90 ℃ for 6 h.Under the optimal conditions,zeolite 4A with a high degree of crystallinity,a small granularity of particles(most of the particle size of zeolite 4A was less than 2 μm) and high calcium ion exchange capacity(314 mg CaCO3/g) was obtained.
Bentonite reacted with NaOH at a high temperature leading to a very reactive starting material for zeolite synthesis.Zeolite 4A was synthesized by hydrothermal method with natural bentonite as raw material.The effects of activation temperature,molar ratio of SiO2/Al2O3,molar ratio of Na2O/SiO2,molar ratio of H2O/Na2O on the properties of the products were investigated by means of XRD,SEM and calcium ion exchange capacity.The results show that the best activation temperature was 600 ℃.After activation of the materials,the composition of the mixed compound was regulated as(molar ratio):SiO2/Al2O3 =1.5,Na2O/SiO2=3 and H2O/Na2O=50,then crystallization was carried out at 90 ℃ for 6 h.Under the optimal conditions,zeolite 4A with a high degree of crystallinity,a small granularity of particles(most of the particle size of zeolite 4A was less than 2 μm) and high calcium ion exchange capacity(314 mg CaCO3/g) was obtained.
2009, 26(6): 1450-1455
Abstract:
An adsorption resin modified by L-tyrosine acid,AJS-02,was synthesized,and its adsorption-desorption performance for Cu2+ was compared with that of NDA-150.The equilibrium adsorption data were fitted to Langmuir isotherm and the adsorption capacity for AJS-02 was higher than that of NDA-150,which may be attributed to the polar groups in the network of AJS-02.The adsorption of Cu2+ to AJS-02 involved physisorption and chemisorption.Kinetic analysis shows that the adsorption rate was mainly governed by the film diffusion.Dynamic adsorption and desorption studies for Cu2+ to AJS-02 show that the breakthrough adsorption capacity and the total adsorption capacity were 4.05×10-3 and 6.44×10-3 moles per liliter resin,respectively.Above 90% regeneration efficiency for the adsorbent was achieved by the desorption of 5% hydrochloric acid.
An adsorption resin modified by L-tyrosine acid,AJS-02,was synthesized,and its adsorption-desorption performance for Cu2+ was compared with that of NDA-150.The equilibrium adsorption data were fitted to Langmuir isotherm and the adsorption capacity for AJS-02 was higher than that of NDA-150,which may be attributed to the polar groups in the network of AJS-02.The adsorption of Cu2+ to AJS-02 involved physisorption and chemisorption.Kinetic analysis shows that the adsorption rate was mainly governed by the film diffusion.Dynamic adsorption and desorption studies for Cu2+ to AJS-02 show that the breakthrough adsorption capacity and the total adsorption capacity were 4.05×10-3 and 6.44×10-3 moles per liliter resin,respectively.Above 90% regeneration efficiency for the adsorbent was achieved by the desorption of 5% hydrochloric acid.
2009, 26(6): 1456-1460
Abstract:
Ag@SiO2 and rhodamine-doped Ag@SiO2 nanocomposites were prepared.Rhodamine fluorescence intensity was enhanced by a factor of 4.7 due to metal-enhanced fluorescence.The Ag core was easily oxidized by H2O2,enhancing the fluorescence release of rhodamine.Glucose oxidase was immobilized on the layer of SiO2 shell by chemical cross linked cluster.A novel method to detect glucose was developed based on metal-enhanced fluorescence in a concentration range of 0.2～6.8 mmol/L with a detection limit of 0.06 mmol/L.Speedy detection response was obtained upon the fast oxidation of Ag core by H2O2.
Ag@SiO2 and rhodamine-doped Ag@SiO2 nanocomposites were prepared.Rhodamine fluorescence intensity was enhanced by a factor of 4.7 due to metal-enhanced fluorescence.The Ag core was easily oxidized by H2O2,enhancing the fluorescence release of rhodamine.Glucose oxidase was immobilized on the layer of SiO2 shell by chemical cross linked cluster.A novel method to detect glucose was developed based on metal-enhanced fluorescence in a concentration range of 0.2～6.8 mmol/L with a detection limit of 0.06 mmol/L.Speedy detection response was obtained upon the fast oxidation of Ag core by H2O2.
2009, 26(6): 1461-1465
Abstract:
A novel dinuclear macrocyclic polyamine Zn(Ⅱ) complex was synthesized from 1,4,7,10-tetraazacyclododecane,the structures of the compounds were characterized by 1H NMR,MS and elemental analysis.The interactions between calf thymus(CT) DNA and these compounds were investigated by fluorometric detection.The fluorescence intensity of the DNA/EB system was decreased to 47.3% of that of the initial system at ccomplex 6/cDNA=0.51,which indicates that the dinuclear complex was inserted into the CT DNA.The order of fluorescence quenching values of the DNA/ethidium bromide(EB) systems by these compounds is as follows:dinuclear macrocyclic polyamine Zn(Ⅱ) complex> dinuclear macrocyclic polyamine ligand> Cyclen-Zn(Ⅱ) complex> Cyclen.
A novel dinuclear macrocyclic polyamine Zn(Ⅱ) complex was synthesized from 1,4,7,10-tetraazacyclododecane,the structures of the compounds were characterized by 1H NMR,MS and elemental analysis.The interactions between calf thymus(CT) DNA and these compounds were investigated by fluorometric detection.The fluorescence intensity of the DNA/EB system was decreased to 47.3% of that of the initial system at ccomplex 6/cDNA=0.51,which indicates that the dinuclear complex was inserted into the CT DNA.The order of fluorescence quenching values of the DNA/ethidium bromide(EB) systems by these compounds is as follows:dinuclear macrocyclic polyamine Zn(Ⅱ) complex> dinuclear macrocyclic polyamine ligand> Cyclen-Zn(Ⅱ) complex> Cyclen.
2009, 26(6): 1466-1470
Abstract:
A modified electrode was fabricated by means of electrodeposition nickel-nickel oxide and copper-cuprous oxide on a glassy carbon electrode in the solution of Ni2+ and Cu2+.It can catalyze the reduction of H2O2 at an applied potential of-0.3 V.The response current was linearly changed with the concentration of H2O2 in a range from 2.5×10-6 to 2.8×10-3 mol/L.The effects of assay conditions on performances of hydrogen peroxide sensor were studied.The preparation of the sensor is simple.The sensor was used for the determination of real samples containing hydrogen peroxide with satisfactory recovery and result.
A modified electrode was fabricated by means of electrodeposition nickel-nickel oxide and copper-cuprous oxide on a glassy carbon electrode in the solution of Ni2+ and Cu2+.It can catalyze the reduction of H2O2 at an applied potential of-0.3 V.The response current was linearly changed with the concentration of H2O2 in a range from 2.5×10-6 to 2.8×10-3 mol/L.The effects of assay conditions on performances of hydrogen peroxide sensor were studied.The preparation of the sensor is simple.The sensor was used for the determination of real samples containing hydrogen peroxide with satisfactory recovery and result.
2009, 26(6): 1471-1475
Abstract:
Tetrabromophthalocyanine cobalt(CoPcBr4),phthalocyanine cobalt(CoPc) and tetra-α-(2,2,4-trimethyl-3-pentyloxy)phthalocyanine cobalt(CoPc(OC8H17)4) modified electrodes were prepared on glassy carbon(GC) electrodes by the adsorption method.Electrocatalytic reduction of molecular oxygen by the modified electrodes was studied in acidic media by means of cyclic voltammetry and linear sweep volammetry.The effects of phthalocyanine cobalt with different substituted groups on electrocatalytic property were compared.The results indicate that they had good electrocatalytic activity for molecular oxygen reduction.CoPc and CoPc(OC8H17)4 could catalyze O2 to give H2O2 via two-electron transfer and the reduction peak potentials of O2 positively shifted by 0.33 V and 0.48 V respectively compared with the bare GC electrode.There are two reduction peaks at about-0.1 V and-0.7 V in the voltammogram obtained at CoPcBr4 modified electrode,indicating that it catalyzed the reduction of O2 to H2O2 and then sequentially reduced H2O2 to H2O.Finally,it completed the four-electron reduction of O2.
Tetrabromophthalocyanine cobalt(CoPcBr4),phthalocyanine cobalt(CoPc) and tetra-α-(2,2,4-trimethyl-3-pentyloxy)phthalocyanine cobalt(CoPc(OC8H17)4) modified electrodes were prepared on glassy carbon(GC) electrodes by the adsorption method.Electrocatalytic reduction of molecular oxygen by the modified electrodes was studied in acidic media by means of cyclic voltammetry and linear sweep volammetry.The effects of phthalocyanine cobalt with different substituted groups on electrocatalytic property were compared.The results indicate that they had good electrocatalytic activity for molecular oxygen reduction.CoPc and CoPc(OC8H17)4 could catalyze O2 to give H2O2 via two-electron transfer and the reduction peak potentials of O2 positively shifted by 0.33 V and 0.48 V respectively compared with the bare GC electrode.There are two reduction peaks at about-0.1 V and-0.7 V in the voltammogram obtained at CoPcBr4 modified electrode,indicating that it catalyzed the reduction of O2 to H2O2 and then sequentially reduced H2O2 to H2O.Finally,it completed the four-electron reduction of O2.
2009, 26(6): 1476-1479
Abstract:
The promoting action of phosphotungstic acid(PWA) in the electrolyte on the oxidation of formic acid at the carbon supported Pt(Pt/C) catalyst was investigated via EDS,XRD and electrochemical methods.It was found that PWA can increase not only the electrocatalytic activity of the Pt/C catalyst electrode for the oxidation of formic acid,but also the electrocatalytic stability.The promoting action is related to the PWA concentration.When the PWA concentration is 0.10 g/L,the promoting action is the best.This is mainly because when the PWA concentration is too high,overfull adsorbed PWA would partially cover the active points of the Pt/C catalyst,leading to the decrease in the electrocatalytic performance of the Pt/C catalyst.
The promoting action of phosphotungstic acid(PWA) in the electrolyte on the oxidation of formic acid at the carbon supported Pt(Pt/C) catalyst was investigated via EDS,XRD and electrochemical methods.It was found that PWA can increase not only the electrocatalytic activity of the Pt/C catalyst electrode for the oxidation of formic acid,but also the electrocatalytic stability.The promoting action is related to the PWA concentration.When the PWA concentration is 0.10 g/L,the promoting action is the best.This is mainly because when the PWA concentration is too high,overfull adsorbed PWA would partially cover the active points of the Pt/C catalyst,leading to the decrease in the electrocatalytic performance of the Pt/C catalyst.
2009, 26(6): 1480-1483
Abstract:
The critical micelle concentration of sodium dodecyl benzene sulfonate,which is a typical anion surfactant,was respectively determined by surface tension,electrical conductivity,UV-Vis absorption spectral and synchronous fluorescence spectral methods.Results show that synchronous fluorescence spectral method is characterized by less sample volume,high sensitivity,and high accuracy.The first and the second critical micelle concentrations were determined by the synchronous fluorescence spectral method to be 1.48 and 6.90 mmol/L respectively,which are well consistent with those data from the traditional surface tension and electrical conductivity methods,thus,verifying the reliability of synchronous fluorescence spectrometry to measure the critical micelle concentrations of surfactants.
The critical micelle concentration of sodium dodecyl benzene sulfonate,which is a typical anion surfactant,was respectively determined by surface tension,electrical conductivity,UV-Vis absorption spectral and synchronous fluorescence spectral methods.Results show that synchronous fluorescence spectral method is characterized by less sample volume,high sensitivity,and high accuracy.The first and the second critical micelle concentrations were determined by the synchronous fluorescence spectral method to be 1.48 and 6.90 mmol/L respectively,which are well consistent with those data from the traditional surface tension and electrical conductivity methods,thus,verifying the reliability of synchronous fluorescence spectrometry to measure the critical micelle concentrations of surfactants.
2009, 26(6): 1484-1488
Abstract:
Enthalpies of formation and bond dissociation energies(BDE) of n-alkanes and the corresponding radicals of up to 14 carbons,involved in pyrolysis of Fischer-Tropsch naphtha were calculated using various density functional theory(DFT) methods.It was found that the MPW1B95/6-311G(d,p) method was the best in term of accuracy among the methods evaluated,including B97-1,BB1K,B1B95,MPWB1K and MPW1B95.On the basis of this good performance,the MPW1B95/6-311G(d,p) method was used for the estimation of large n-alkanes and their resulting radicals.C—C BDEs of n-alkanes were also examined.The enthalpies of formation of n-alkanes and the radicals had deviations of 0.8 and 2.7 kJ/mol respectively compared with experimental data.For C—C BDEs of n-alkanes,this method predicted the results with a mean absolute deviation of 3.1 kJ/mol.It is noted that by means of the MPW1B95/6-311G(d,p) method the enthalpies of formation can be calculated satisfactorily and the C—C BDEs and their change trend can be predicted reasonably.
Enthalpies of formation and bond dissociation energies(BDE) of n-alkanes and the corresponding radicals of up to 14 carbons,involved in pyrolysis of Fischer-Tropsch naphtha were calculated using various density functional theory(DFT) methods.It was found that the MPW1B95/6-311G(d,p) method was the best in term of accuracy among the methods evaluated,including B97-1,BB1K,B1B95,MPWB1K and MPW1B95.On the basis of this good performance,the MPW1B95/6-311G(d,p) method was used for the estimation of large n-alkanes and their resulting radicals.C—C BDEs of n-alkanes were also examined.The enthalpies of formation of n-alkanes and the radicals had deviations of 0.8 and 2.7 kJ/mol respectively compared with experimental data.For C—C BDEs of n-alkanes,this method predicted the results with a mean absolute deviation of 3.1 kJ/mol.It is noted that by means of the MPW1B95/6-311G(d,p) method the enthalpies of formation can be calculated satisfactorily and the C—C BDEs and their change trend can be predicted reasonably.
2009, 26(6): 1489-1491
Abstract:
2,5-Di-tert-butyl 1,4-di-(p-phenylene nitriles oxyl) benzene was synthesized via nucleophilic substitution reaction of 4-fluorobenzonitrile with 2,5-di-tert-butyl-p-dihydroxybenzene(yield 87.00%,white crystals,mp 280 ℃).Then 2,5-di-tert-butyl-1,4-di-(p-benzoic acid oxyl) benzene with two ether bonds and two tert-butyls was obtained by alkaline hydrolysis of 2,5-di-tert-butyl 1,4-di-(p-phenylene nitriles oxyl) benzene(yield 72.78%,white acicular crystals,mp>340 ℃).The chemical structure of this product was confirmed by means of elemental analysis,IR,1H NMR,13C NMR and MS.
2,5-Di-tert-butyl 1,4-di-(p-phenylene nitriles oxyl) benzene was synthesized via nucleophilic substitution reaction of 4-fluorobenzonitrile with 2,5-di-tert-butyl-p-dihydroxybenzene(yield 87.00%,white crystals,mp 280 ℃).Then 2,5-di-tert-butyl-1,4-di-(p-benzoic acid oxyl) benzene with two ether bonds and two tert-butyls was obtained by alkaline hydrolysis of 2,5-di-tert-butyl 1,4-di-(p-phenylene nitriles oxyl) benzene(yield 72.78%,white acicular crystals,mp>340 ℃).The chemical structure of this product was confirmed by means of elemental analysis,IR,1H NMR,13C NMR and MS.
Aqueous Two-phase Gas Floatation Spectrometric Determination of Trace Oxytetracycline in Waste Water
2009, 26(6): 1492-1494
Abstract:
The hydrophobic complex composed of Zn(Ⅱ) and oxytetracycline(OTC) was floated into organic phase under the optimal conditions:pH=9,tetrahydrofuran as organic solvent,sodium chloride as separating phase reagent on the home-made floatation equipment.The data was obtained by spectrophotometry after floatation,the linear regression equation was A=2.046×105c(mol/L)+0.015,linear range was from 1.7×10-7 to 9.3×10-5 mol/L,correlation coefficient(r) was 0.999 6,relative recovery was 98.7%~100.5%,and the limit of detection was 7.16×10-8 mol/L.It can be applied to the analysis of trace OTC in waste water.
The hydrophobic complex composed of Zn(Ⅱ) and oxytetracycline(OTC) was floated into organic phase under the optimal conditions:pH=9,tetrahydrofuran as organic solvent,sodium chloride as separating phase reagent on the home-made floatation equipment.The data was obtained by spectrophotometry after floatation,the linear regression equation was A=2.046×105c(mol/L)+0.015,linear range was from 1.7×10-7 to 9.3×10-5 mol/L,correlation coefficient(r) was 0.999 6,relative recovery was 98.7%~100.5%,and the limit of detection was 7.16×10-8 mol/L.It can be applied to the analysis of trace OTC in waste water.
2009, 26(6): 1495-1497
Abstract:
Morphine,codeine and 6-acetyl morphine in human blood were detemined via solid-phase extra-ction and gas chromatography/mass spectrometry-selected ion monitoring,with ethyl morphine as internal standard,3 opiates spiked in blank blood were extracted wtih a solid-phase cartridge.The fluent was evapo-rated to dryness followed by being derivatized with MBTFA,and then it was analyzed directly by GC/MS in selected ion mode.The method was validated in a range of 10~1 000 μg/L with the drug-spiked blood,and the reactor responded linearly over the studied range(R2>0.99 for the 3 drugs).The relative standard deviations(RSD) for intra and inter-days are less than 10% and 16% respectively;the relative extraction recoveries are 90%~116%,90%~110% and 79%~102% sequenfyl for 3 drugs above,and LODs were less than 1,0.5 and 3 μg/L respectively,which promised the perspective application of the method in detecting trace amounts of opium in human blood.
Morphine,codeine and 6-acetyl morphine in human blood were detemined via solid-phase extra-ction and gas chromatography/mass spectrometry-selected ion monitoring,with ethyl morphine as internal standard,3 opiates spiked in blank blood were extracted wtih a solid-phase cartridge.The fluent was evapo-rated to dryness followed by being derivatized with MBTFA,and then it was analyzed directly by GC/MS in selected ion mode.The method was validated in a range of 10~1 000 μg/L with the drug-spiked blood,and the reactor responded linearly over the studied range(R2>0.99 for the 3 drugs).The relative standard deviations(RSD) for intra and inter-days are less than 10% and 16% respectively;the relative extraction recoveries are 90%~116%,90%~110% and 79%~102% sequenfyl for 3 drugs above,and LODs were less than 1,0.5 and 3 μg/L respectively,which promised the perspective application of the method in detecting trace amounts of opium in human blood.
2009, 26(6): 1498-1500
Abstract:
The surface morphology of glutathione(GSH) complex with cadmium and copper on silicon surface was studied by means of atomic force microscopy(AFM).The results show that the GSH-Cd(Ⅱ) complex at diluted concentration dispersed disorderly on the surface with spheroid or cylinder states.The apparent height of the spheroid is(3.6±0.1) nm and the width is(60±10) nm.The complex aggregated with the increase of its concentration,the dimmers and multimers aggregated from monomers formed clusters.The difference of AFM images of GSH-Cd(Ⅱ) complex in different buffer solution systems is small.For GSH-Cu complex,firstly,some string bead chains were formed by aggregation of the uniform spheroid particles,then,under the influence of different directions,the long chains formed two kinds of different surface morphologies orderly and uniformly.
The surface morphology of glutathione(GSH) complex with cadmium and copper on silicon surface was studied by means of atomic force microscopy(AFM).The results show that the GSH-Cd(Ⅱ) complex at diluted concentration dispersed disorderly on the surface with spheroid or cylinder states.The apparent height of the spheroid is(3.6±0.1) nm and the width is(60±10) nm.The complex aggregated with the increase of its concentration,the dimmers and multimers aggregated from monomers formed clusters.The difference of AFM images of GSH-Cd(Ⅱ) complex in different buffer solution systems is small.For GSH-Cu complex,firstly,some string bead chains were formed by aggregation of the uniform spheroid particles,then,under the influence of different directions,the long chains formed two kinds of different surface morphologies orderly and uniformly.
