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2002 Volume 13 Issue 10
2002, 13(10): 919-920
Abstract:
Using 4-Dialkylaminopyridinium salt as a thermal stable phase-transfer catalyst (PTC),the excellent results were obtained in the halogen-exchange fluorination.
Using 4-Dialkylaminopyridinium salt as a thermal stable phase-transfer catalyst (PTC),the excellent results were obtained in the halogen-exchange fluorination.
2002, 13(10): 921-922
Abstract:
A highly efficient catalyst indium (III) tribromide is used to synthesize 5-alkoxycarbonyl-4-hydrocarbyl-3,4-dihydropyrimidin-2(1H)-ones by a three-component coupling of β-keto ester, aldehydes and urea through improved Biginelli reaction.
A highly efficient catalyst indium (III) tribromide is used to synthesize 5-alkoxycarbonyl-4-hydrocarbyl-3,4-dihydropyrimidin-2(1H)-ones by a three-component coupling of β-keto ester, aldehydes and urea through improved Biginelli reaction.
2002, 13(10): 923-925
Abstract:
4-oxo-2,2,6,6-tetramethylpiperidinyl-1-oxy radical (TEMPO), a nitroxide, oxidized 4-substituted Hantzsch 1,4-dihydropyridines (DHP) under UV irradiation in CH3CN to give aromatic products in good yields. A possible mechanism for the oxidation was suggested.
4-oxo-2,2,6,6-tetramethylpiperidinyl-1-oxy radical (TEMPO), a nitroxide, oxidized 4-substituted Hantzsch 1,4-dihydropyridines (DHP) under UV irradiation in CH3CN to give aromatic products in good yields. A possible mechanism for the oxidation was suggested.
2002, 13(10): 926-928
Abstract:
1,2-Dihydro-4-(4-hydroxyphenyl) (2H)phthalazin-1-one (DHPZ) was sulfonated in concentrated sulfuric acid. Poly(phthalazinone ether ketone) containing pendant sodium sulfonate group was synthesized from sulfonated and pure 1,2-dihydro-4-(4-hydroxyphenyl) (2H)phthalazin-1-one, and 4,4'-difluorodiphenylketone. The sulfonated monomer and sulfonated polymer were characterized with FT-IR and 1H-NMR.
1,2-Dihydro-4-(4-hydroxyphenyl) (2H)phthalazin-1-one (DHPZ) was sulfonated in concentrated sulfuric acid. Poly(phthalazinone ether ketone) containing pendant sodium sulfonate group was synthesized from sulfonated and pure 1,2-dihydro-4-(4-hydroxyphenyl) (2H)phthalazin-1-one, and 4,4'-difluorodiphenylketone. The sulfonated monomer and sulfonated polymer were characterized with FT-IR and 1H-NMR.
2002, 13(10): 929-930
Abstract:
A first total synthesis of isoliquiritin was accomplished starting from p-hydroxybenzaldehyde and 2,4-dihydroxyacetylphenone. The key step is condensation reaction. In synthetic process need not protect the hydroxy group of reacting substance.
A first total synthesis of isoliquiritin was accomplished starting from p-hydroxybenzaldehyde and 2,4-dihydroxyacetylphenone. The key step is condensation reaction. In synthetic process need not protect the hydroxy group of reacting substance.
2002, 13(10): 931-932
Abstract:
The reduction reagents prepared from sodium borohydride, I2 and a catalytic amount of chiral ferrocenyl amino alcohols 2a-e have been successfully applied to the enantioselective reduction of ketones. The optically active secondary alcohols were obtained in moderate enantiomeric excess and high chemical yield.
The reduction reagents prepared from sodium borohydride, I2 and a catalytic amount of chiral ferrocenyl amino alcohols 2a-e have been successfully applied to the enantioselective reduction of ketones. The optically active secondary alcohols were obtained in moderate enantiomeric excess and high chemical yield.
2002, 13(10): 933-934
Abstract:
The effect of cosolvent on the palladium catalyst which catalyze alkoxycarbonylation of allyl bromide in supercritical CO2 has been investigated. It was found that a small amount of cosolvent such as ethanol, CH2Cl2 and cyclohexane can affect both reaction yields and selectivities largely. Ethanol was the most favorable cosolvent for increasing the total yield of unsaturated esters and the selectivity of 3-butenoic acid ester. Using cosolvent ethanol and cocatalyst FeCl2 simultaneously can lead to better reaction results.
The effect of cosolvent on the palladium catalyst which catalyze alkoxycarbonylation of allyl bromide in supercritical CO2 has been investigated. It was found that a small amount of cosolvent such as ethanol, CH2Cl2 and cyclohexane can affect both reaction yields and selectivities largely. Ethanol was the most favorable cosolvent for increasing the total yield of unsaturated esters and the selectivity of 3-butenoic acid ester. Using cosolvent ethanol and cocatalyst FeCl2 simultaneously can lead to better reaction results.
2002, 13(10): 935-936
Abstract:
A facile total synthetic route to (±)-nimbonone and (±)-12-ethyl-13-methoxy-8,11,13-podocarpatriene was developed. The Wittig reaction of α-cyclocitral with (3-methoxybenzyl) triphenylphosphonium and intramolecular cyclization with BF3·Et2O in the synthetic progress were applied. In order to induce the ethyl substituent, Fiedel-Crafts acetylation and then decarbonylation had been employed.
A facile total synthetic route to (±)-nimbonone and (±)-12-ethyl-13-methoxy-8,11,13-podocarpatriene was developed. The Wittig reaction of α-cyclocitral with (3-methoxybenzyl) triphenylphosphonium and intramolecular cyclization with BF3·Et2O in the synthetic progress were applied. In order to induce the ethyl substituent, Fiedel-Crafts acetylation and then decarbonylation had been employed.
2002, 13(10): 937-938
Abstract:
The relative stereochemistry of an intermediate 2 in the total synthesis of hainanolide 1 was studied by various NMR spectroscopic techniques.
The relative stereochemistry of an intermediate 2 in the total synthesis of hainanolide 1 was studied by various NMR spectroscopic techniques.
2002, 13(10): 939-941
Abstract:
Pd(0) Complex prepared from Pd(dba)2 and chiral quinolinyl-oxazoline ligand can catalyze alkylation and cyclization reaction of 1,4-dichlorobut-2-ene 1 with anion of N-(diphenylmethylene) amino acetonitrile 2 to provide (E)-2-ethenyl-1-N-(diphenylmethylene) amino cyclopropane carbonitrile 3 with 100% de and 20% ee. Reduction of (E)-3 by diimide followed by acidic hydrolysis afforded (1S, 2S)-2-ethyl-1-aminocyclopropanecarboxylic acid 9, a natural product coronamic acid.
Pd(0) Complex prepared from Pd(dba)2 and chiral quinolinyl-oxazoline ligand can catalyze alkylation and cyclization reaction of 1,4-dichlorobut-2-ene 1 with anion of N-(diphenylmethylene) amino acetonitrile 2 to provide (E)-2-ethenyl-1-N-(diphenylmethylene) amino cyclopropane carbonitrile 3 with 100% de and 20% ee. Reduction of (E)-3 by diimide followed by acidic hydrolysis afforded (1S, 2S)-2-ethyl-1-aminocyclopropanecarboxylic acid 9, a natural product coronamic acid.
2002, 13(10): 942-944
Abstract:
Novel 2-aryloxy-5-(2-furfurylidene)-4H-imidazolin-4-ones 6 were synthesized by aza-Wittig reaction of vinyliminophosphorane 4 with phenyl isocyanate and subsequent condensation with various substituted phenols in the presence of catalytic amount of potassium carbonate. The products are confirmed by 1H NMR, MS, IR and elementary analysis.
Novel 2-aryloxy-5-(2-furfurylidene)-4H-imidazolin-4-ones 6 were synthesized by aza-Wittig reaction of vinyliminophosphorane 4 with phenyl isocyanate and subsequent condensation with various substituted phenols in the presence of catalytic amount of potassium carbonate. The products are confirmed by 1H NMR, MS, IR and elementary analysis.
2002, 13(10): 945-948
Abstract:
This paper reports the synthesis and the nonlinear optical property of a series of new chromophores which contain furan ring as the only conjugation bridge for the first time. They are characterized by UV-VIS, FT-IR, 1H NMR, MS and elemental analysis. Their dipole moment and the first-order molecular hyperpolarizability (β) are calculated and compared with those of the analogues containing either benzene or thiophene as the conjugation bridge.
This paper reports the synthesis and the nonlinear optical property of a series of new chromophores which contain furan ring as the only conjugation bridge for the first time. They are characterized by UV-VIS, FT-IR, 1H NMR, MS and elemental analysis. Their dipole moment and the first-order molecular hyperpolarizability (β) are calculated and compared with those of the analogues containing either benzene or thiophene as the conjugation bridge.
2002, 13(10): 949-952
Abstract:
Two new molecules containing oxadiazoles and triphenylamine-stilbene moiety were synthesized. Their luminescent properties were determined, which indicated that they had strong green fluorescent properties. All the two molecules can be used as green organic electroluminescence materials.
Two new molecules containing oxadiazoles and triphenylamine-stilbene moiety were synthesized. Their luminescent properties were determined, which indicated that they had strong green fluorescent properties. All the two molecules can be used as green organic electroluminescence materials.
2002, 13(10): 953-954
Abstract:
A new bromo-sesquiterpene 1, has been isolated from the alga Caloglossa leprieurii collected from the XiSha islands in south china sea. Its structure has been determined on the basis of spectral analysis, and The relative configuration of 1 was assigned on the basis of difference spectrum of NOE.
A new bromo-sesquiterpene 1, has been isolated from the alga Caloglossa leprieurii collected from the XiSha islands in south china sea. Its structure has been determined on the basis of spectral analysis, and The relative configuration of 1 was assigned on the basis of difference spectrum of NOE.
2002, 13(10): 955-956
Abstract:
One new grayanane diterpene glucoside, rhodomoside A 1 was isolated from the roots of Rhododendron molle G. Don (Ericaceae). Its structure was elucidated on the basis of spectral analysis.
One new grayanane diterpene glucoside, rhodomoside A 1 was isolated from the roots of Rhododendron molle G. Don (Ericaceae). Its structure was elucidated on the basis of spectral analysis.
2002, 13(10): 957-958
Abstract:
A new alkaloid has been isolated from the root of Patrinia scabra. Its structure was elucidated as 2'-acetamido-3'-phenyl propyl 2-benzamido-3-phenyl propionate by extensive spectroscopic analysis.
A new alkaloid has been isolated from the root of Patrinia scabra. Its structure was elucidated as 2'-acetamido-3'-phenyl propyl 2-benzamido-3-phenyl propionate by extensive spectroscopic analysis.
2002, 13(10): 959-962
Abstract:
Two new diphyllin glycosides, mananthoside A (1) and B (2), together with six known compounds, were isolated from the ethanolic extract of the whole plants of Mananthes patentiflora.Their structures were determined on the basis of chemical and spectral evidences.
Two new diphyllin glycosides, mananthoside A (1) and B (2), together with six known compounds, were isolated from the ethanolic extract of the whole plants of Mananthes patentiflora.Their structures were determined on the basis of chemical and spectral evidences.
2002, 13(10): 963-964
Abstract:
Chemical investigation of L.sagitta afforded two new eremophilenolides, which were identified as 6β-angeloyloxy-10β-hydroxy-8β-methoxy-eremophil-7(11)-en-12, 8α-olide (1) and 6β,8β-dimethoxy-10β-hydroxy-eremophil-7(11)-en-12, 8α-olide (2). Their structures were established by spectroscopic methods including 2D NMR experiments.
Chemical investigation of L.sagitta afforded two new eremophilenolides, which were identified as 6β-angeloyloxy-10β-hydroxy-8β-methoxy-eremophil-7(11)-en-12, 8α-olide (1) and 6β,8β-dimethoxy-10β-hydroxy-eremophil-7(11)-en-12, 8α-olide (2). Their structures were established by spectroscopic methods including 2D NMR experiments.
2002, 13(10): 965-967
Abstract:
A new sesquiterpene lactone, strychnilactone (1), together with five known sesquite-rpenoids,linderane (2), lindenenol (3), linderalactone (4), hydroxylindestenolide (5), pseudoneolinderane (6) have been isolated from the extracts of Supercritical Fluid Extraction of Lindera strychnifolia. The structure of the new compound was elucidated by means of spectroscopic analysis. And the relative configuration of 1 was assigned on the basis of NOE analysis.
A new sesquiterpene lactone, strychnilactone (1), together with five known sesquite-rpenoids,linderane (2), lindenenol (3), linderalactone (4), hydroxylindestenolide (5), pseudoneolinderane (6) have been isolated from the extracts of Supercritical Fluid Extraction of Lindera strychnifolia. The structure of the new compound was elucidated by means of spectroscopic analysis. And the relative configuration of 1 was assigned on the basis of NOE analysis.
Determination of the Flavonoids from Ginkgo Biloba Extract by High Performance Liquid Chromatography
2002, 13(10): 968-970
Abstract:
HPLC method for analysis of the flavonoids from ginkgo biloba extract (GBE) was studied. By suitable selection of columns, symmetrical chromatographic peaks were obtained without using acidic modifier in the mobile phase, which can eliminate the time for cleaning the chromatographic system and simplify the analystic method for GBE. Experimental conditions:column:Hypersil BDS C18, 5μm×4×250 mm; column temperature:35℃; mobile phase:46% methanol-54% water; flow rate:0.7 mL/min; detection wavelength:360nm.
HPLC method for analysis of the flavonoids from ginkgo biloba extract (GBE) was studied. By suitable selection of columns, symmetrical chromatographic peaks were obtained without using acidic modifier in the mobile phase, which can eliminate the time for cleaning the chromatographic system and simplify the analystic method for GBE. Experimental conditions:column:Hypersil BDS C18, 5μm×4×250 mm; column temperature:35℃; mobile phase:46% methanol-54% water; flow rate:0.7 mL/min; detection wavelength:360nm.
2002, 13(10): 971-972
Abstract:
An electrochemical method for determination of horseradish peroxidase (HRP) was developed using a capillary catalytic system. HRP can be measured in several minutes with a detection limit of 4.8×10-12 mol/L or 47 zmol (S/N=3).
An electrochemical method for determination of horseradish peroxidase (HRP) was developed using a capillary catalytic system. HRP can be measured in several minutes with a detection limit of 4.8×10-12 mol/L or 47 zmol (S/N=3).
2002, 13(10): 973-976
Abstract:
Using two β-cyclodextrin derivatives (CDs) with long chain of acyl groups as chiral stationary phases (CSPs) of capillary gas chromatography (CGC), the enantiomers of racemic allethrone and propargyllone were well resolved after derived with acetyl chloride. The enantiomer excess values (e.e.%) of 1S-allethrone and 1S-propargyllone were also determined successfully using these CDs.
Using two β-cyclodextrin derivatives (CDs) with long chain of acyl groups as chiral stationary phases (CSPs) of capillary gas chromatography (CGC), the enantiomers of racemic allethrone and propargyllone were well resolved after derived with acetyl chloride. The enantiomer excess values (e.e.%) of 1S-allethrone and 1S-propargyllone were also determined successfully using these CDs.
2002, 13(10): 977-978
Abstract:
A sensitive and selective chemiluminescence (CL) method was developed for the determination of cysteine. This method is based on that the weak CL of cysteine oxidized with cerium (IV) can be greatly enhanced by quinine, and the total cysteine in human serum can be detected through simply diluting with water, showing a simpler analytical characteristic.
A sensitive and selective chemiluminescence (CL) method was developed for the determination of cysteine. This method is based on that the weak CL of cysteine oxidized with cerium (IV) can be greatly enhanced by quinine, and the total cysteine in human serum can be detected through simply diluting with water, showing a simpler analytical characteristic.
2002, 13(10): 979-981
Abstract:
Amino acids in individual human lymphocytes were determined by capillary zone electrophoresis with electrochemical detection after on-capillary derivatization. In order to inject cells easily, a cell injector was designed. Four amino acids (serine, alanine, taurine, and glycine) in single human lymphocytes have been identified. Quantitation has been accomplished through the use of calibration curves.
Amino acids in individual human lymphocytes were determined by capillary zone electrophoresis with electrochemical detection after on-capillary derivatization. In order to inject cells easily, a cell injector was designed. Four amino acids (serine, alanine, taurine, and glycine) in single human lymphocytes have been identified. Quantitation has been accomplished through the use of calibration curves.
2002, 13(10): 982-984
Abstract:
Capillary zone electrophoresis was employed for the analysis of histamine in single rat peritoneal mast cells using an amperometric detector. In this method, individual mast cells and then 0.02 mol/L NaOH as a lysing solution are injected into the front end of the separation capillary. A cell injector was constructed for easy injection of single cells. Histamine in single mast cells has been identified and quantified.
Capillary zone electrophoresis was employed for the analysis of histamine in single rat peritoneal mast cells using an amperometric detector. In this method, individual mast cells and then 0.02 mol/L NaOH as a lysing solution are injected into the front end of the separation capillary. A cell injector was constructed for easy injection of single cells. Histamine in single mast cells has been identified and quantified.
2002, 13(10): 985-987
Abstract:
A carbon fiber-gold/mercury dual-electrode for capillary electrophoresis is constructed.Cysteine, glutathione, ascorbic acid and uric acid can be detected simultaneously and selectively at the dual-electrode, respectively. The capillary electrophoresis/dual-electrode detection system has been used to determine these compounds in human blood samples.
A carbon fiber-gold/mercury dual-electrode for capillary electrophoresis is constructed.Cysteine, glutathione, ascorbic acid and uric acid can be detected simultaneously and selectively at the dual-electrode, respectively. The capillary electrophoresis/dual-electrode detection system has been used to determine these compounds in human blood samples.
2002, 13(10): 988-990
Abstract:
A kind of small band-gap conjugated polymers-poly (pyrrolyl methines) and their precursors-(poly pyrrolyl methanes) have been synthesized by a simple method and characterized by 1HNMR, FT-IR, TGA and UV-Vis. These polymers can be dissolved in high polar solvents such as DMSO, DMF or NMP. The results reveals that the band-gap of the synthesized conjugated polymers are in the range of 0.96~1.14 eV and they all belong to the small band-gap polymers. The conductivity of doped products with iodine is in the range of semiconductor.
A kind of small band-gap conjugated polymers-poly (pyrrolyl methines) and their precursors-(poly pyrrolyl methanes) have been synthesized by a simple method and characterized by 1HNMR, FT-IR, TGA and UV-Vis. These polymers can be dissolved in high polar solvents such as DMSO, DMF or NMP. The results reveals that the band-gap of the synthesized conjugated polymers are in the range of 0.96~1.14 eV and they all belong to the small band-gap polymers. The conductivity of doped products with iodine is in the range of semiconductor.
2002, 13(10): 991-992
Abstract:
New monomer N-(4-carboxyphenyl)-NL-(propyltriethoxysilyl) urea (1) which acts as both a ligand for Tb3+ ion and a sol-gel precursor has been synthesized and characterized by 1H NMR, and MS. Hybrid luminescent thin films consisting of organoterbium covalently bonded to a silica-based network have been obtained in situ via a sol-gel approach. Strong line emission of Tb3+ ion was observed from the hybrid luminescent films under UV excitation.
New monomer N-(4-carboxyphenyl)-NL-(propyltriethoxysilyl) urea (1) which acts as both a ligand for Tb3+ ion and a sol-gel precursor has been synthesized and characterized by 1H NMR, and MS. Hybrid luminescent thin films consisting of organoterbium covalently bonded to a silica-based network have been obtained in situ via a sol-gel approach. Strong line emission of Tb3+ ion was observed from the hybrid luminescent films under UV excitation.
2002, 13(10): 993-996
Abstract:
Polyacrylic acid particles in nano-scale were synthesized using an inverse (W/O) emulsion polymerization method. The particle size and size change of inverse micelles which solubilize a part of monomer solution was monitored by PCS (photon correlation spectroscopy) and the particles of polyacrylic acid were viewed in scanning electron microscope for the first time.It was concluded that the inverse micelles were primarily the polymerization reaction sites.
Polyacrylic acid particles in nano-scale were synthesized using an inverse (W/O) emulsion polymerization method. The particle size and size change of inverse micelles which solubilize a part of monomer solution was monitored by PCS (photon correlation spectroscopy) and the particles of polyacrylic acid were viewed in scanning electron microscope for the first time.It was concluded that the inverse micelles were primarily the polymerization reaction sites.
2002, 13(10): 997-1000
Abstract:
The single & two photon excited fluorescence property and crystal structure of a substituted stilbene-type compound trans-4-diethylamino-4'-bromostilbene (DEABS) has been reported. The results indicate that this compound has strong two photon excited blue fluorescence at 440 nm when the 700 nm laser was used as the pump source.
The single & two photon excited fluorescence property and crystal structure of a substituted stilbene-type compound trans-4-diethylamino-4'-bromostilbene (DEABS) has been reported. The results indicate that this compound has strong two photon excited blue fluorescence at 440 nm when the 700 nm laser was used as the pump source.
2002, 13(10): 1001-1002
Abstract:
The fluorescence spectra of the interaction between four new distamycin analogs and DNA from herring sperm have been studied in detail. The fluorescence quenching of the DNA by the analogs was observed, and the fluorescence intensity of the DNA was attenuated exponentially with the increasing of the analogs concentration.
The fluorescence spectra of the interaction between four new distamycin analogs and DNA from herring sperm have been studied in detail. The fluorescence quenching of the DNA by the analogs was observed, and the fluorescence intensity of the DNA was attenuated exponentially with the increasing of the analogs concentration.
2002, 13(10): 1003-1004
Abstract:
Three functional substituted crown ethers were synthesized as liquid membrane transport carriers for amino acids. The result obtained shows that this kind of ditopic ligands can transport sodium salt of amino acids in good rate value especially the one with two pyridinyl groups as binding site outside the macrocycle.
Three functional substituted crown ethers were synthesized as liquid membrane transport carriers for amino acids. The result obtained shows that this kind of ditopic ligands can transport sodium salt of amino acids in good rate value especially the one with two pyridinyl groups as binding site outside the macrocycle.
2002, 13(10): 1005-1006
Abstract:
The interaction between ethyl orange (Eto, guest) and β-cyclodextrin dimers (1a~d, host) bridged with 2-t-butoxycarbonyl (Boc)-amino diacid was investigated. A remarkable synergic complexation of two cavities in host molecule was observed.
The interaction between ethyl orange (Eto, guest) and β-cyclodextrin dimers (1a~d, host) bridged with 2-t-butoxycarbonyl (Boc)-amino diacid was investigated. A remarkable synergic complexation of two cavities in host molecule was observed.
2002, 13(10): 1007-1010
Abstract:
The interaction between amphiphilic porphyrin and phenothiazine in AOT/isooctane/water reverse micelle was investigated by UV-Vis spectra. A new absorption complex between the two species is formed in such circumstances, which is ascribed to the enrichment of the components by the reverse micelle. The fluorescence quenching of CHTTP by PTH becomes more efficient after the formation of the absorption complex.
The interaction between amphiphilic porphyrin and phenothiazine in AOT/isooctane/water reverse micelle was investigated by UV-Vis spectra. A new absorption complex between the two species is formed in such circumstances, which is ascribed to the enrichment of the components by the reverse micelle. The fluorescence quenching of CHTTP by PTH becomes more efficient after the formation of the absorption complex.
2002, 13(10): 1011-1012
Abstract:
Thermoregulated phase-separable Ru3(CO)12/PETPP (PETPP=P[p-C6H4O (CH2CH2O)n H]3, n=6) complex catalyst was first applied in the hydrogenation of styrene. Under the conditions:P(H2)=2.0MPa, T=90℃, styrene could be completely transferred and the yield of ethylbenzene reached up to 99.5%. After simple decantation, the catalyst could be reused for ten times without decreasing in activity.
Thermoregulated phase-separable Ru3(CO)12/PETPP (PETPP=P[p-C6H4O (CH2CH2O)n H]3, n=6) complex catalyst was first applied in the hydrogenation of styrene. Under the conditions:P(H2)=2.0MPa, T=90℃, styrene could be completely transferred and the yield of ethylbenzene reached up to 99.5%. After simple decantation, the catalyst could be reused for ten times without decreasing in activity.
2002, 13(10): 1013-1016
Abstract:
Experimental results in this work demonstrate that PW12-H2SO4/SiO2 catalyst is a good and durable catalyst for vapor phase nitration of benzene to nitrobenzene (NB) using 65% nitric acid at normal pressure. It retains the advantages of using H2SO4 as catalyst and the addition of phosphotungstic acid holds back the effusion of sulfuric acid. This new catalyst keeps high activity (the conversion of HNO3 is more than 92%), high selectivity of NB (more than 97%) and high space time yield (STY 1.5 kg NB/kg cat.h) even after 150 h on stream, under condition of 423 K, SV=3200 ml/g h.
Experimental results in this work demonstrate that PW12-H2SO4/SiO2 catalyst is a good and durable catalyst for vapor phase nitration of benzene to nitrobenzene (NB) using 65% nitric acid at normal pressure. It retains the advantages of using H2SO4 as catalyst and the addition of phosphotungstic acid holds back the effusion of sulfuric acid. This new catalyst keeps high activity (the conversion of HNO3 is more than 92%), high selectivity of NB (more than 97%) and high space time yield (STY 1.5 kg NB/kg cat.h) even after 150 h on stream, under condition of 423 K, SV=3200 ml/g h.
2002, 13(10): 1017-1020
Abstract:
Nanocrystalline Pb1-1.5xLaxZr0.5Ti0.5O3 (x=0.01-0.06, PLZT) powders with particle size from 30 to 150 nm were hydrothermally synthesized from the gels under mild conditions. The reaction conditions such as La content, reaction temperature and time were studied in detail and optimal conditions were established for synthesizing PLZT powders with different La contents.The effects of La content, alkali concentration, reaction temperature and time on the particle size were studied.
Nanocrystalline Pb1-1.5xLaxZr0.5Ti0.5O3 (x=0.01-0.06, PLZT) powders with particle size from 30 to 150 nm were hydrothermally synthesized from the gels under mild conditions. The reaction conditions such as La content, reaction temperature and time were studied in detail and optimal conditions were established for synthesizing PLZT powders with different La contents.The effects of La content, alkali concentration, reaction temperature and time on the particle size were studied.
2002, 13(10): 1021-1024
Abstract:
The complex fluoride LiBaF3 is solvothermally synthesized at 180℃ and characterized by means of X-ray powder diffraction, scanning electron microscopy, thermogravimetric analysis and infrared spectroscopy. In the solvothermal process, the solvents, mole ratios of initial mixtures and reaction temperature play important roles in the growth of the single crystal.
The complex fluoride LiBaF3 is solvothermally synthesized at 180℃ and characterized by means of X-ray powder diffraction, scanning electron microscopy, thermogravimetric analysis and infrared spectroscopy. In the solvothermal process, the solvents, mole ratios of initial mixtures and reaction temperature play important roles in the growth of the single crystal.
2002, 13(10): 1025-1028
Abstract:
A simple model, i.e. sodium di(2-ethylhexyl) sulfosuccinate (AOT) represented by one-head and two-tail beads tied together by a harmonic spring and water or isooctane by one bead,was put forward via Dissipative Particles Dynamics (DPD) simulation method. Using the changes of interfacial tension between water and oil phase, a ternary phase diagram of AOT/water/isooctane system was drawn. From the simulation, one conclusion is shown that DPD simulation can be considered as an adjunct to experiments.
A simple model, i.e. sodium di(2-ethylhexyl) sulfosuccinate (AOT) represented by one-head and two-tail beads tied together by a harmonic spring and water or isooctane by one bead,was put forward via Dissipative Particles Dynamics (DPD) simulation method. Using the changes of interfacial tension between water and oil phase, a ternary phase diagram of AOT/water/isooctane system was drawn. From the simulation, one conclusion is shown that DPD simulation can be considered as an adjunct to experiments.
