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2012 Volume 29 Issue 2
2012, 29(2): 123-128
doi: 10.3724/SP.J.1095.2012.00202
Abstract:
Using oxygen as the electron acceptor in microbial fuel cells(MFC) has many advantages.However,the kinetics of oxygen reduction is rather slow,which may cause the loss of cathode potential.Thereby enhancing the oxygen reduction activity is one of the main focuses of MFC research.The progress of abiotic cathode catalysts of MFC is reviewed in this paper,while the catalytic activities of precious metal Pt,transition metal macrocyclic complexes,and non-noble metallic oxide for oxygen reduction are particularly focused.The transition metal macrocyclic complexes and non-noble metal oxides catalysts display good performances and are expected to become the substitutes for the MFC abiotic cathode Pt catalysts.
Using oxygen as the electron acceptor in microbial fuel cells(MFC) has many advantages.However,the kinetics of oxygen reduction is rather slow,which may cause the loss of cathode potential.Thereby enhancing the oxygen reduction activity is one of the main focuses of MFC research.The progress of abiotic cathode catalysts of MFC is reviewed in this paper,while the catalytic activities of precious metal Pt,transition metal macrocyclic complexes,and non-noble metallic oxide for oxygen reduction are particularly focused.The transition metal macrocyclic complexes and non-noble metal oxides catalysts display good performances and are expected to become the substitutes for the MFC abiotic cathode Pt catalysts.
2012, 29(2): 129-134
doi: 10.3724/SP.J.1095.2012.00088
Abstract:
Propinic acid containing trifluoromethyl group was synthesized from 2-bromo-3,3,3-trifluoropropene,which was obtained via two steps:addition of 3,3,3-trifluoropropene and bromine followed by an elimination reaction.Then the reaction of magnesium,2-bromotrifluoropropene,different initiators and carbon dioxide in tetrahydrofuran produced 1-bromo-2-trifluoromethylpropionic,0.8 g of the product was obtained by extrated with 10% sodium carbonate solution.The purity of the product was 99.6% and the yield was 3.6%.Its structure was characterized by MS,IR,1H NMR and 13C NMR.The main by-products were 1,1-difluoropropadiene,2,3-bis(trifluoromethyl)-1,3-butadiene and their [2+2] and [2+4] cycloaddition products.The suitable synthesis conditions of the reactions were determined as follows:THF was used as reaction solvent,dibromoethane as the initiator,reaction temperature for preparing the Grignard reagent was 30℃,the Grignard reaction temperature was 0℃.
Propinic acid containing trifluoromethyl group was synthesized from 2-bromo-3,3,3-trifluoropropene,which was obtained via two steps:addition of 3,3,3-trifluoropropene and bromine followed by an elimination reaction.Then the reaction of magnesium,2-bromotrifluoropropene,different initiators and carbon dioxide in tetrahydrofuran produced 1-bromo-2-trifluoromethylpropionic,0.8 g of the product was obtained by extrated with 10% sodium carbonate solution.The purity of the product was 99.6% and the yield was 3.6%.Its structure was characterized by MS,IR,1H NMR and 13C NMR.The main by-products were 1,1-difluoropropadiene,2,3-bis(trifluoromethyl)-1,3-butadiene and their [2+2] and [2+4] cycloaddition products.The suitable synthesis conditions of the reactions were determined as follows:THF was used as reaction solvent,dibromoethane as the initiator,reaction temperature for preparing the Grignard reagent was 30℃,the Grignard reaction temperature was 0℃.
2012, 29(2): 135-139
doi: 10.3724/SP.J.1095.2012.00094
Abstract:
An efficient oxidative bromination reaction of phenol by KBr-H2O2 has been achieved in the presence of ammonium tungstophosphate catalyst supported on silica with different loadings,which were synthesized by sol-gel method.The effects of the reaction time and catalyst amount on the oxidative bromination reaction were also investigated.The results indicated that the Keggin structure of ammonium tungstophosphate could be retained after supported on silica,and these catalysts exhibited high bromination reaction catalytic activity with a yield of 96.4% and high selectivity of p-bromophenol with a p/o ratio of 3.2.After reaction,these catalysts can be recycled and still exhibited catalytic activity with a yield of 87.4% and a p/o ratio of 1.6 after four cycle reactions.
An efficient oxidative bromination reaction of phenol by KBr-H2O2 has been achieved in the presence of ammonium tungstophosphate catalyst supported on silica with different loadings,which were synthesized by sol-gel method.The effects of the reaction time and catalyst amount on the oxidative bromination reaction were also investigated.The results indicated that the Keggin structure of ammonium tungstophosphate could be retained after supported on silica,and these catalysts exhibited high bromination reaction catalytic activity with a yield of 96.4% and high selectivity of p-bromophenol with a p/o ratio of 3.2.After reaction,these catalysts can be recycled and still exhibited catalytic activity with a yield of 87.4% and a p/o ratio of 1.6 after four cycle reactions.
2012, 29(2): 140-143
doi: 10.3724/SP.J.1095.2012.00119
Abstract:
A new fluorous proline-derived ligand has been synthesized and applied to the copper-catalyzed Henry reaction.The reaction conditions were optimized in terms of ligand,Cu source,solvent and base taking the reaction of 4-nitrobenzaldehyde and nitromethane as a model reaction.The optimized conditions are:using fluorous proline imide as ligand,copper acetate as copper source,methanol as solvent and triethylamine as base and the reaction was carried out at room temperature.A wide range of substrates were investigated under the optimized conditions and the yields of the target products varied from 53% to 98%.
A new fluorous proline-derived ligand has been synthesized and applied to the copper-catalyzed Henry reaction.The reaction conditions were optimized in terms of ligand,Cu source,solvent and base taking the reaction of 4-nitrobenzaldehyde and nitromethane as a model reaction.The optimized conditions are:using fluorous proline imide as ligand,copper acetate as copper source,methanol as solvent and triethylamine as base and the reaction was carried out at room temperature.A wide range of substrates were investigated under the optimized conditions and the yields of the target products varied from 53% to 98%.
2012, 29(2): 144-148
doi: 10.3724/SP.J.1095.2012.00126
Abstract:
A series of novel N-(substituted benzyl)-3,5-bis(benzylidene)-4-piperidones(8a~8j) were synthesized uisng substituted benzylamines as precursors via a series of Michael addition,Dieckmann condensation,hydrolysis decarboxylation and Aldol condensation.The structures were confirmed by 1H NMR,IR,MS and elemental analysis.The preliminary biological activity tests by MTT assay indicated that some of the target compounds had good antiproliferative activities against K562,MDR-MB-231 and HO8910PM cells,and therefore showed potential anti-tumors bioactivity.
A series of novel N-(substituted benzyl)-3,5-bis(benzylidene)-4-piperidones(8a~8j) were synthesized uisng substituted benzylamines as precursors via a series of Michael addition,Dieckmann condensation,hydrolysis decarboxylation and Aldol condensation.The structures were confirmed by 1H NMR,IR,MS and elemental analysis.The preliminary biological activity tests by MTT assay indicated that some of the target compounds had good antiproliferative activities against K562,MDR-MB-231 and HO8910PM cells,and therefore showed potential anti-tumors bioactivity.
2012, 29(2): 149-154
doi: 10.3724/SP.J.1095.2012.00124
Abstract:
A series of PET-PMT(PEMT) copolyesters were synthesized by direct esterification using terephthalatic acid(PTA)-ethylene glycol(EG)-2-methoxy-1,3-propanediol(MPD,obtained from conversion of bio-glycerol to displace 1,3-propanediol) as co-monomers,with different ratio of PET/PMT.The molecular structure and chemical composition of PEMT were confirmed by FT-IR and 1H NMR.Molecular mass and distributions of PEMT were determined by GPC.The intrinsic viscosity of PEMT was measured,while thermal and crystallization properties of the PEMT were characterized using DSC analysis.Results show that the chain segments of PMT containing in PEMT are much higher than the molar ratio of MPD in feed,and consequently,PEMT has higher intrinsic viscosity than PET.The crystallization degree is decreased with MPD inserting into the polyester.The crystallization and melting behavior of PEMT is similar to that of PET when the feed molar ratio of MPD to PTA is less than 0.4.The mass-average relative molecular mass(Mw),intrinsic viscosity(η),glass transition temperature(Tg),and melting point(Tm) of the synthesized PEMT-40(the actual ratio of n(PMT):n(PET) is 24:76) is 50216,0.458 dL/g,68.32℃,and 211.07℃,respectively.However,when the feed molar ratio of MPD to PTA is more than 0.6,the copolyester of PEMT becomes an amorphous material.
A series of PET-PMT(PEMT) copolyesters were synthesized by direct esterification using terephthalatic acid(PTA)-ethylene glycol(EG)-2-methoxy-1,3-propanediol(MPD,obtained from conversion of bio-glycerol to displace 1,3-propanediol) as co-monomers,with different ratio of PET/PMT.The molecular structure and chemical composition of PEMT were confirmed by FT-IR and 1H NMR.Molecular mass and distributions of PEMT were determined by GPC.The intrinsic viscosity of PEMT was measured,while thermal and crystallization properties of the PEMT were characterized using DSC analysis.Results show that the chain segments of PMT containing in PEMT are much higher than the molar ratio of MPD in feed,and consequently,PEMT has higher intrinsic viscosity than PET.The crystallization degree is decreased with MPD inserting into the polyester.The crystallization and melting behavior of PEMT is similar to that of PET when the feed molar ratio of MPD to PTA is less than 0.4.The mass-average relative molecular mass(Mw),intrinsic viscosity(η),glass transition temperature(Tg),and melting point(Tm) of the synthesized PEMT-40(the actual ratio of n(PMT):n(PET) is 24:76) is 50216,0.458 dL/g,68.32℃,and 211.07℃,respectively.However,when the feed molar ratio of MPD to PTA is more than 0.6,the copolyester of PEMT becomes an amorphous material.
2012, 29(2): 155-160
doi: 10.3724/SP.J.1095.2012.00133
Abstract:
A new compound 4-[(trans-(2-pyridyl))styryl]-N,N-dibutylbenzenamine has been synthesized and characterized by elemental analysis,UV,and X-ray single-crystal diffraction studies.The compound crystallizes in the triclinic system with space group P-1,a=1.15041(3) nm,b=1.45746(4) nm,c=1.51598(4) nm,Z=4,V=2.33068(11) nm3,R1=0.0962,wR2=0.2630.The result showed that the molecule with donor,π-conjugated bridge and acceptor(D-π-A) structure has good planarity,which results in effective electronic delocalization and increased intramolecular charge transfer.The molecules are linked by intermolecular C-H…π.It is believed that π electrons play a significant role for their packing,which attributed it with higher Stock shifts in photoluminescence properties.
A new compound 4-[(trans-(2-pyridyl))styryl]-N,N-dibutylbenzenamine has been synthesized and characterized by elemental analysis,UV,and X-ray single-crystal diffraction studies.The compound crystallizes in the triclinic system with space group P-1,a=1.15041(3) nm,b=1.45746(4) nm,c=1.51598(4) nm,Z=4,V=2.33068(11) nm3,R1=0.0962,wR2=0.2630.The result showed that the molecule with donor,π-conjugated bridge and acceptor(D-π-A) structure has good planarity,which results in effective electronic delocalization and increased intramolecular charge transfer.The molecules are linked by intermolecular C-H…π.It is believed that π electrons play a significant role for their packing,which attributed it with higher Stock shifts in photoluminescence properties.
2012, 29(2): 161-165
doi: 10.3724/SP.J.1095.2012.00134
Abstract:
We prepared azobenzene dendron monolayers on the Au or quartz substrates by DCC(N,N-dicyclohexylcarbodiimide)-catalyzed surface amidation reactions between the carboxyl acid groups at the focal point of the dendrons and the amine groups on the surface of Au or quartz.infrared reflection-absorption spectroscopy(IRRAS),UV-Vis absorption and Raman spectroscopies were performed to characterize these azobenzene dendron monolayers.The thickness of the G-4 monolayers with different isomeric forms was measured using ellipsometry spectra,and a value of(2.38±0.09) nm was obtained for the trans-form,and(1.88±0.08) nm for the cis-form.The interaction between the G-4 monolayers in different isomeric forms and proteins with different isoelectric points(pI) was studied by surface plasma resonance(SPR),which demonstrated that the G-4 monolayers had a negatively charged surface that preferentially adsorbed positive proteins.The surface potential of the dendron monolayers became more negative when the monolayers was changed from the trans-form to cis-form,resulting in adsorbing more positively charged proteins.
We prepared azobenzene dendron monolayers on the Au or quartz substrates by DCC(N,N-dicyclohexylcarbodiimide)-catalyzed surface amidation reactions between the carboxyl acid groups at the focal point of the dendrons and the amine groups on the surface of Au or quartz.infrared reflection-absorption spectroscopy(IRRAS),UV-Vis absorption and Raman spectroscopies were performed to characterize these azobenzene dendron monolayers.The thickness of the G-4 monolayers with different isomeric forms was measured using ellipsometry spectra,and a value of(2.38±0.09) nm was obtained for the trans-form,and(1.88±0.08) nm for the cis-form.The interaction between the G-4 monolayers in different isomeric forms and proteins with different isoelectric points(pI) was studied by surface plasma resonance(SPR),which demonstrated that the G-4 monolayers had a negatively charged surface that preferentially adsorbed positive proteins.The surface potential of the dendron monolayers became more negative when the monolayers was changed from the trans-form to cis-form,resulting in adsorbing more positively charged proteins.
2012, 29(2): 166-173
doi: 10.3724/SP.J.1095.2012.00087
Abstract:
Polyacrylic acid/activated carbon composite hydrogel(PAA/AC) was prepared by free radical solution polymerization of acrylic acid(AA) using ammonium persulfate as an initiator and N,N'-methylene-bis-acrylamide as a crosslinker in the presence of activated carbon.The equilibrium swelling degree and the dynamics of the gels swelling in distilled water,saline and buffer solutions with different pH were studied.The results showed that the activated carbon enhanced the swelling capacity of PAA gel effectively,the PAA/AC hydrogel exhibits higher equilibrium degree of swelling(SWeq) than PAA hydrogel over the range of pH investigated,and the SWeq of PAA/AC is about 303 and 60(g/g) in distilled water and saline,respectively,which is about 2.4 times higher than that of PAA hydrogel.The mechanism of the swelling was also discussed,and the results showed that the aggregated structure of the polymer chains might be destroyed by the intervention of the activated carbon,which caused a decrease in interactions among polymer chains and an increase in the swelling capacity of PAA/AC gel.The glass transition temperatures(Tg) and cross sectional morphologies of PAA and PAA/AC gels were measured by differential scanning calorimetry(DSC) and scanning electron microscope(SEM),respectively,and the results further proved a decrease in the interactions among polymer chains.
Polyacrylic acid/activated carbon composite hydrogel(PAA/AC) was prepared by free radical solution polymerization of acrylic acid(AA) using ammonium persulfate as an initiator and N,N'-methylene-bis-acrylamide as a crosslinker in the presence of activated carbon.The equilibrium swelling degree and the dynamics of the gels swelling in distilled water,saline and buffer solutions with different pH were studied.The results showed that the activated carbon enhanced the swelling capacity of PAA gel effectively,the PAA/AC hydrogel exhibits higher equilibrium degree of swelling(SWeq) than PAA hydrogel over the range of pH investigated,and the SWeq of PAA/AC is about 303 and 60(g/g) in distilled water and saline,respectively,which is about 2.4 times higher than that of PAA hydrogel.The mechanism of the swelling was also discussed,and the results showed that the aggregated structure of the polymer chains might be destroyed by the intervention of the activated carbon,which caused a decrease in interactions among polymer chains and an increase in the swelling capacity of PAA/AC gel.The glass transition temperatures(Tg) and cross sectional morphologies of PAA and PAA/AC gels were measured by differential scanning calorimetry(DSC) and scanning electron microscope(SEM),respectively,and the results further proved a decrease in the interactions among polymer chains.
2012, 29(2): 174-179
doi: 10.3724/SP.J.1095.2012.00118
Abstract:
A couple of new benzimidazole chelating resins,bisbenzimidazole supported on phenol-formaldehyde(PTBMZs),were synthesized by phenolformaldehyde condensation of tetrabenzimidazole ligand.The PTBMZs have a 2.06~3.02 mmol of ligand content per gram of the resin.Their structures were characterized by solid-state 13C crossing-polarization and magic-angle spinning(CP MAS) NMR,FT-IR spectroscopy.Batch adsorption capacities were determined for the chloride of some divalent metal cations in buffer solutions in the pH rang of 1.0 to 6.0.The adsorption capacities of the PTBMZ-1 under non-competitive condition are 1.15 mmol/g for Cu2+ at pH=5 and the ligand occupations are 35.7%.Elemental analysis and electron paramagnetic resonance(EPR) studies suggested that complexes with the metal cation to ligand ratio of mainly 1:2 were formed on the BBEAH modified resins via tridentate chalete structure.
A couple of new benzimidazole chelating resins,bisbenzimidazole supported on phenol-formaldehyde(PTBMZs),were synthesized by phenolformaldehyde condensation of tetrabenzimidazole ligand.The PTBMZs have a 2.06~3.02 mmol of ligand content per gram of the resin.Their structures were characterized by solid-state 13C crossing-polarization and magic-angle spinning(CP MAS) NMR,FT-IR spectroscopy.Batch adsorption capacities were determined for the chloride of some divalent metal cations in buffer solutions in the pH rang of 1.0 to 6.0.The adsorption capacities of the PTBMZ-1 under non-competitive condition are 1.15 mmol/g for Cu2+ at pH=5 and the ligand occupations are 35.7%.Elemental analysis and electron paramagnetic resonance(EPR) studies suggested that complexes with the metal cation to ligand ratio of mainly 1:2 were formed on the BBEAH modified resins via tridentate chalete structure.
2012, 29(2): 180-185
doi: 10.3724/SP.J.1095.2012.00129
Abstract:
Attapulgite(ATT) modified by the hydrochloric acid(HATT) was grafted by amino-silane coupling agent KH-792(N-beta-(aminoethyl)-gamma-aminopropyl-trimethoxysilane).Thermal behavior and the structure of the grafted HATT(KHATT) were characterized by FTIR,TGA,DSC,XRD and BET.The results showed that the KH-792 molecules were successfully grafted onto the HATT surface.The adsorption of Cr(Ⅵ) onto KHATT in stimulative water was also investigated.The results showed that removal rate of Cr(Ⅵ) in water was relatively high(85.15%) when the loading of KHATT is 3 g/L,pH of the water is 5.5 and the adsorption time of the KHATT is 40 min.The adsorption capacity of KHATT after four times regeneration retained at least 90% of the initial one,showing a high application value.In addition,an adsorption mechanism of KHATT for Cr(Ⅵ) was proposed.
Attapulgite(ATT) modified by the hydrochloric acid(HATT) was grafted by amino-silane coupling agent KH-792(N-beta-(aminoethyl)-gamma-aminopropyl-trimethoxysilane).Thermal behavior and the structure of the grafted HATT(KHATT) were characterized by FTIR,TGA,DSC,XRD and BET.The results showed that the KH-792 molecules were successfully grafted onto the HATT surface.The adsorption of Cr(Ⅵ) onto KHATT in stimulative water was also investigated.The results showed that removal rate of Cr(Ⅵ) in water was relatively high(85.15%) when the loading of KHATT is 3 g/L,pH of the water is 5.5 and the adsorption time of the KHATT is 40 min.The adsorption capacity of KHATT after four times regeneration retained at least 90% of the initial one,showing a high application value.In addition,an adsorption mechanism of KHATT for Cr(Ⅵ) was proposed.
2012, 29(2): 186-190
doi: 10.3724/SP.J.1095.2012.00103
Abstract:
The magnetite nanoparticles were synthesized by thermal decomposition of iron(Ⅲ) acetylacetonate(Fe(acac)3) in methoxy polyethylene glycol(MPEG),which was used as solvent,reducing agent,and modifying agent in this reaction.The morphologies and phase compositions of the nanoparticles were determined by transmission electron microscopy and X-ray diffraction,respectively.The modification of the nanoparticles was characterized using Fourier transform infrared spectroscopy.Magnetic properties were measured using superconducting quantum interference device(SQUID).The zeta potential of the nanoparticles was determined.The results indicate that the magnetite nanoparticles obtained in this way have a much uniform size and monodispersion.The diameter is about(10.1±1.6) nm.The nanoparticles show superparamagnetic behavior at 300 K with saturation magnetization of 45 A·m2/kg.The FTIR spectroscopic results prove the existence of -COO- covalently attached to the surface of the magnetite nanoparticles,and the zeta potential results show that the nanoparticles have negative surface about -25 mV.Compared with the magnetite nanoparticles synthesized in triethylene glycol(TREG),the nanoparticles synthesized in MPEG show a longer dispersion time in deionized water(for more than 60 days),due to the steric and electrostatic interactions between the nanoparticles.
The magnetite nanoparticles were synthesized by thermal decomposition of iron(Ⅲ) acetylacetonate(Fe(acac)3) in methoxy polyethylene glycol(MPEG),which was used as solvent,reducing agent,and modifying agent in this reaction.The morphologies and phase compositions of the nanoparticles were determined by transmission electron microscopy and X-ray diffraction,respectively.The modification of the nanoparticles was characterized using Fourier transform infrared spectroscopy.Magnetic properties were measured using superconducting quantum interference device(SQUID).The zeta potential of the nanoparticles was determined.The results indicate that the magnetite nanoparticles obtained in this way have a much uniform size and monodispersion.The diameter is about(10.1±1.6) nm.The nanoparticles show superparamagnetic behavior at 300 K with saturation magnetization of 45 A·m2/kg.The FTIR spectroscopic results prove the existence of -COO- covalently attached to the surface of the magnetite nanoparticles,and the zeta potential results show that the nanoparticles have negative surface about -25 mV.Compared with the magnetite nanoparticles synthesized in triethylene glycol(TREG),the nanoparticles synthesized in MPEG show a longer dispersion time in deionized water(for more than 60 days),due to the steric and electrostatic interactions between the nanoparticles.
2012, 29(2): 191-195
doi: 10.3724/SP.J.1095.2012.00154
Abstract:
ZnS nanoparticles on the self-assembled monolayer of 3-sulfopropyltrimethoxylsilane were fabricated by the reaction between ZnSO4 and thioacetamide in aqueous solution.It was found that a compact ZnS nanoparticle film with string-like particles was obtained when the aqueous solution contained only Zn2+.Interestingly,the morphology of ZnS nanoparticles changed from the compact film to hemispheres with herringbone-like structure when Mn2+ was added into the aqueous solution.XRD and EDS results indicated that the manganese ions were not doped into the ZnS nanoparticles.These experimental results showed that Mn2+ played a key role in the morphological control of the ZnS nanoparticles,even though Mn2+ ions were absent in the final as-prepared products.The mechanism of the formation of ZnS with Mn2+ presence was discussed.
ZnS nanoparticles on the self-assembled monolayer of 3-sulfopropyltrimethoxylsilane were fabricated by the reaction between ZnSO4 and thioacetamide in aqueous solution.It was found that a compact ZnS nanoparticle film with string-like particles was obtained when the aqueous solution contained only Zn2+.Interestingly,the morphology of ZnS nanoparticles changed from the compact film to hemispheres with herringbone-like structure when Mn2+ was added into the aqueous solution.XRD and EDS results indicated that the manganese ions were not doped into the ZnS nanoparticles.These experimental results showed that Mn2+ played a key role in the morphological control of the ZnS nanoparticles,even though Mn2+ ions were absent in the final as-prepared products.The mechanism of the formation of ZnS with Mn2+ presence was discussed.
2012, 29(2): 196-199
doi: 10.3724/SP.J.1095.2012.00109
Abstract:
A two-dimensional organic-inorganic hybrid perovskite C7H12N2PbBr4 has been grown via a solution-cooling process by employing the organic cation-2-(2-aminomethyl) pyridinium to control the hybrid compound.The structure of C7H12N2PbBr4 was determined by single-crystal X-ray diffractions to be orthorhombic(Pbca,No.61),with the primitive unit cell of dimensions:a=1.7023 nm,b=0.8289 nm,c=2.0224 nm,and Z=8.The inorganic sublattice is built up from corner-sharing PbBr6 octahedra forming infinite two-dimensional layered sheets.The organic cations(2-(2-aminomethyl) pyridinium) adopt obviously distorted configuration to connect the inorganic sheets by special hydrogen bonding.Moreover,optical absorption is used to gain more information of the title compound.The characteristic photoluminescence emission peak is located at 422 nm.
A two-dimensional organic-inorganic hybrid perovskite C7H12N2PbBr4 has been grown via a solution-cooling process by employing the organic cation-2-(2-aminomethyl) pyridinium to control the hybrid compound.The structure of C7H12N2PbBr4 was determined by single-crystal X-ray diffractions to be orthorhombic(Pbca,No.61),with the primitive unit cell of dimensions:a=1.7023 nm,b=0.8289 nm,c=2.0224 nm,and Z=8.The inorganic sublattice is built up from corner-sharing PbBr6 octahedra forming infinite two-dimensional layered sheets.The organic cations(2-(2-aminomethyl) pyridinium) adopt obviously distorted configuration to connect the inorganic sheets by special hydrogen bonding.Moreover,optical absorption is used to gain more information of the title compound.The characteristic photoluminescence emission peak is located at 422 nm.
2012, 29(2): 200-208
doi: 10.3724/SP.J.1095.2012.00082
Abstract:
[Et2NH2][(4-MeC6H4O)2PS2](N,N-diethylammonium O,O'-di(4-methylphenyl)dithiophosphate,NOP) was synthesized and characterized by elemental analysis,IR,TG-DSC,and single crystal X-ray diffraction analysis.The thermal stability and corrosion inhibition were investigated.The crystallographic structure analysis reveals that the title compound crystallizes in monoclinic system,P 21/n space group,a=1.4241(3) nm,b=2.0087(4) nm,c=1.4366(3) nm,V=3.9599(15) nm3,Dc=1.286 Mg/m3,Z=8,F(000)=1632,μ(MoKα)=0.360 mm-1,S=1.001,(Δ/σ)max=0.001,and R1=0.0776,wR2=0.1749(I>2σ(I)).There are two independent subunits in the asymmetric structure unit of NOP,and infinite one-dimensional chain structure is formed via N-H…S hydrogen bonds between the subunits.The corrosion inhibition study showed that the NOP could effectively restrain corrosion of Q235 steel in H2SO4 solution.It was shown that the adsorption of NOP on the Q235 steel surface is consistent with the Langmuir adsorption isotherm,and the corrosion inhibition depends on both physical and chemical sorptions.CCDC:813309
[Et2NH2][(4-MeC6H4O)2PS2](N,N-diethylammonium O,O'-di(4-methylphenyl)dithiophosphate,NOP) was synthesized and characterized by elemental analysis,IR,TG-DSC,and single crystal X-ray diffraction analysis.The thermal stability and corrosion inhibition were investigated.The crystallographic structure analysis reveals that the title compound crystallizes in monoclinic system,P 21/n space group,a=1.4241(3) nm,b=2.0087(4) nm,c=1.4366(3) nm,V=3.9599(15) nm3,Dc=1.286 Mg/m3,Z=8,F(000)=1632,μ(MoKα)=0.360 mm-1,S=1.001,(Δ/σ)max=0.001,and R1=0.0776,wR2=0.1749(I>2σ(I)).There are two independent subunits in the asymmetric structure unit of NOP,and infinite one-dimensional chain structure is formed via N-H…S hydrogen bonds between the subunits.The corrosion inhibition study showed that the NOP could effectively restrain corrosion of Q235 steel in H2SO4 solution.It was shown that the adsorption of NOP on the Q235 steel surface is consistent with the Langmuir adsorption isotherm,and the corrosion inhibition depends on both physical and chemical sorptions.CCDC:813309
2012, 29(2): 209-215
doi: 10.3724/SP.J.1095.2012.00080
Abstract:
The inhibition effect of 2-aminopyrimidine(2-AP) on the corrosion of cold rolled steel(CRS) in 1.0~5.0 mol/L HCl media at 20~50℃ has been studied by mass loss,potentiodynamic polarization curves and electrochemical impedance spectroscopy(EIS) methods.The results showed that the neutral 2-AP is a good inhibitor for CRS,and the adsorption of 2-AP on the CRS surface follows the amended Langmuir adsorption isotherm equation.Inhibition efficiency increases with the inhibitor concentration,while decreases with temperature and the concentration of HCl.Polarization curves showed that 2-AP is a mixed-type inhibitor.EIS spectra exhibited one capacitive loop,and the charge transfer resistance increased with the inhibitor 2-AP concentration.
The inhibition effect of 2-aminopyrimidine(2-AP) on the corrosion of cold rolled steel(CRS) in 1.0~5.0 mol/L HCl media at 20~50℃ has been studied by mass loss,potentiodynamic polarization curves and electrochemical impedance spectroscopy(EIS) methods.The results showed that the neutral 2-AP is a good inhibitor for CRS,and the adsorption of 2-AP on the CRS surface follows the amended Langmuir adsorption isotherm equation.Inhibition efficiency increases with the inhibitor concentration,while decreases with temperature and the concentration of HCl.Polarization curves showed that 2-AP is a mixed-type inhibitor.EIS spectra exhibited one capacitive loop,and the charge transfer resistance increased with the inhibitor 2-AP concentration.
2012, 29(2): 216-221
doi: 10.3724/SP.J.1095.2012.00110
Abstract:
A sensor for determination of hydrogen peroxide(H2O2) based on 4-(2-pyridylazo)-resorcinol(PAR) polymer film modified glassy carbon electrodes(GCE) was fabricated.Electrochemical properties and characteristics of the PAR polymer film modified electrode for H2O2 reduction were investigated using cyclic voltammetry and chronoamperometry methods.The results showed that the modified electrode exhibited good electrocatalytic activity towards the reduction of H2O2 at a low potential.The chronoamperometric detection of H2O2 was carried out at-0.45 V in 0.1 mol/L phosphate buffered solution(pH=8.0).The peak currents of H2O2 reduction varied linearly with the concentration in the range of 2×10-5~1.76×10-3 mol/L,with a linearly dependent coefficient r=-0.99983,the detection limit(S/N=3) was 3 μmol/L.The modified electrode showed high sensitivity,good stability,easy preparation and exhibited better anti-interference to ascorbic acid,uric acid and glucose.
A sensor for determination of hydrogen peroxide(H2O2) based on 4-(2-pyridylazo)-resorcinol(PAR) polymer film modified glassy carbon electrodes(GCE) was fabricated.Electrochemical properties and characteristics of the PAR polymer film modified electrode for H2O2 reduction were investigated using cyclic voltammetry and chronoamperometry methods.The results showed that the modified electrode exhibited good electrocatalytic activity towards the reduction of H2O2 at a low potential.The chronoamperometric detection of H2O2 was carried out at-0.45 V in 0.1 mol/L phosphate buffered solution(pH=8.0).The peak currents of H2O2 reduction varied linearly with the concentration in the range of 2×10-5~1.76×10-3 mol/L,with a linearly dependent coefficient r=-0.99983,the detection limit(S/N=3) was 3 μmol/L.The modified electrode showed high sensitivity,good stability,easy preparation and exhibited better anti-interference to ascorbic acid,uric acid and glucose.
2012, 29(2): 222-227
doi: 10.3724/SP.J.1095.2012.00130
Abstract:
By using the fourier transform-surface plasmon resonance(FT-SPR) technique,the FT-SPR responses(R) toward NaCl,KCl and ethanol with various aqueous concentrations were measured.A quantitative equation of R=1.53×105(n-1.3333) was set up for the response toward the concentration dependent solution refractive index(n).The result shows that the FT-SPR response of 15 cm-1 is obtained upon 0.0001 change in the refractive index.This equation is promising in direct measurement of refractive index of unknown media.
By using the fourier transform-surface plasmon resonance(FT-SPR) technique,the FT-SPR responses(R) toward NaCl,KCl and ethanol with various aqueous concentrations were measured.A quantitative equation of R=1.53×105(n-1.3333) was set up for the response toward the concentration dependent solution refractive index(n).The result shows that the FT-SPR response of 15 cm-1 is obtained upon 0.0001 change in the refractive index.This equation is promising in direct measurement of refractive index of unknown media.
2012, 29(2): 228-232
doi: 10.3724/SP.J.1095.2012.00091
Abstract:
Liquid-liquid extraction(LLE) was used to analyze the contents of 1,4-butanediol(BDO) in the depolymerization solution.The LLE data for the system were measured at 30℃ when n-octanol was used as extracting reagent.Activity coefficient models were established to correlate the LLE data of the system using the Extended-UNIQUAC equation,in which the binary interaction energy parameters of water+BDO+n-octanol ternary system were obtained through a simplex fitting method.The results show that the composition of raffinate phase can be predicted reliably by analyzing the composition of extract phase.Therefore,the contents of BDO in the solution can be calculated.The method is accurate and simple and can be used as the common analytic method for this system.
Liquid-liquid extraction(LLE) was used to analyze the contents of 1,4-butanediol(BDO) in the depolymerization solution.The LLE data for the system were measured at 30℃ when n-octanol was used as extracting reagent.Activity coefficient models were established to correlate the LLE data of the system using the Extended-UNIQUAC equation,in which the binary interaction energy parameters of water+BDO+n-octanol ternary system were obtained through a simplex fitting method.The results show that the composition of raffinate phase can be predicted reliably by analyzing the composition of extract phase.Therefore,the contents of BDO in the solution can be calculated.The method is accurate and simple and can be used as the common analytic method for this system.
2012, 29(2): 233-237
doi: 10.3724/SP.J.1095.2012.00093
Abstract:
In pH=3.29 acidic medium,the interaction of Hg(Ⅱ) with thioacetamide(TAA) occurs and results in greatly enhanced resonance light scattering(RLS) signals characterized by a peak at 379.0 nm.The results show that the enhanced RLS signals intensity(ΔIRLS) at 379.0 nm is proportional to the concentration of TAA.A RLS method for the determination of trace mercury ions is then established accordingly.The linear range is 0.2~10.0 μmol/L.The limit of detection is 0.02 μmol/L for Hg(Ⅱ).Effects of the acidity,ionic strength,temperature and coexisting substances interference are also investigated.The method has been applied successfully to the determination of Hg2+ in environmental samples.
In pH=3.29 acidic medium,the interaction of Hg(Ⅱ) with thioacetamide(TAA) occurs and results in greatly enhanced resonance light scattering(RLS) signals characterized by a peak at 379.0 nm.The results show that the enhanced RLS signals intensity(ΔIRLS) at 379.0 nm is proportional to the concentration of TAA.A RLS method for the determination of trace mercury ions is then established accordingly.The linear range is 0.2~10.0 μmol/L.The limit of detection is 0.02 μmol/L for Hg(Ⅱ).Effects of the acidity,ionic strength,temperature and coexisting substances interference are also investigated.The method has been applied successfully to the determination of Hg2+ in environmental samples.
2012, 29(2): 238-244
doi: 10.3724/SP.J.1095.2012.00116
Abstract:
The interaction of 4'-O-(α-L-oleandrosyl)daunorubicin(ODNR) with calf thymus DNA(ctDNA) in Tris-HCl buffer solution(pH=7.4) was studied by fluorescence and ultraviolet absorption spectroscopies.Effects of the ionic strength,KI quenching,and the ODNR binding differences between the single stranded DNA(ssDNA) and the double stranded DNA(dsDNA) were studied.The results showed that the major binding mode between ODNR and ctDNA was intercalation.The intrinsic fluorescence of ODNR was quenched by ctDNA through static quenching procedure.The binding constants(K) and sites(n) at different temperatures were obtained by Scatchard equation.The predominant intermolecular forces are likely the hydrophobic and electrostatic interactions according to the thermodynamic parameters.
The interaction of 4'-O-(α-L-oleandrosyl)daunorubicin(ODNR) with calf thymus DNA(ctDNA) in Tris-HCl buffer solution(pH=7.4) was studied by fluorescence and ultraviolet absorption spectroscopies.Effects of the ionic strength,KI quenching,and the ODNR binding differences between the single stranded DNA(ssDNA) and the double stranded DNA(dsDNA) were studied.The results showed that the major binding mode between ODNR and ctDNA was intercalation.The intrinsic fluorescence of ODNR was quenched by ctDNA through static quenching procedure.The binding constants(K) and sites(n) at different temperatures were obtained by Scatchard equation.The predominant intermolecular forces are likely the hydrophobic and electrostatic interactions according to the thermodynamic parameters.
