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1993 Volume 4 Issue 3
1993, 4(3): 189-190
Abstract:
(±)Euchrenonc a8,7,2'-dihydroxy-8,5'-di(γ,γ-dimethylallyl)-4'-methoxyflavanone,has been synthesized by the condensation of 2-hydroxy-4-methoxymethoxy-3-(γ,γ-dimethylallyl)acctophenonc with 4-methoxy-2-methoxymethoxy-5-(γ,γ-dimethylallyl)benzaldchyde followed by cyclization and demethoxymethylation.
(±)Euchrenonc a8,7,2'-dihydroxy-8,5'-di(γ,γ-dimethylallyl)-4'-methoxyflavanone,has been synthesized by the condensation of 2-hydroxy-4-methoxymethoxy-3-(γ,γ-dimethylallyl)acctophenonc with 4-methoxy-2-methoxymethoxy-5-(γ,γ-dimethylallyl)benzaldchyde followed by cyclization and demethoxymethylation.
1993, 4(3): 191-194
Abstract:
New bicyclic alkaloids. 3-methoxycarbonyl-4-methyl-9-azabicyclo[4.2.1]non-3-ene(Ⅱ)and 3-acetyl-4-methyl-9-azabicyclo[4.2.1]non-3-ene(Ⅲ).have been synthesized from tropinone through eight and ten steps.respectively.The key features of the synthsis are the cuprate coupling reaction of acyclic enol phpsphates at lower temperatures to achieve high stereoselectivity and de-N-methylation with 2,2,2-trichloroethoethoxycarhonyl chloride proceeded smoothly.
New bicyclic alkaloids. 3-methoxycarbonyl-4-methyl-9-azabicyclo[4.2.1]non-3-ene(Ⅱ)and 3-acetyl-4-methyl-9-azabicyclo[4.2.1]non-3-ene(Ⅲ).have been synthesized from tropinone through eight and ten steps.respectively.The key features of the synthsis are the cuprate coupling reaction of acyclic enol phpsphates at lower temperatures to achieve high stereoselectivity and de-N-methylation with 2,2,2-trichloroethoethoxycarhonyl chloride proceeded smoothly.
1993, 4(3): 195-196
Abstract:
The polyacetylated(4,6-dimethylpyrimidin-2-yl)1-thioglycopyrano-sides(5-8) were obtained in high yields with stereoselectivity by phase-transfercatalyzed synthesis,and their structures were confirmed by elemental analysisand IR,1H-NMR spectral data.
The polyacetylated(4,6-dimethylpyrimidin-2-yl)1-thioglycopyrano-sides(5-8) were obtained in high yields with stereoselectivity by phase-transfercatalyzed synthesis,and their structures were confirmed by elemental analysisand IR,1H-NMR spectral data.
1993, 4(3): 197-198
Abstract:
2-Butoxy-5-fluoro-3H-4-pyrimidone derivatives of D-glucuronic acid having 0-glycosidic linkage or N-glycosidic linkage were synthesized and their anticancer activity tested.Their structures were confirmed by elementary analysis,IR spectraand 1HNMR.
2-Butoxy-5-fluoro-3H-4-pyrimidone derivatives of D-glucuronic acid having 0-glycosidic linkage or N-glycosidic linkage were synthesized and their anticancer activity tested.Their structures were confirmed by elementary analysis,IR spectraand 1HNMR.
1993, 4(3): 199-202
Abstract:
Nine new 3-acetyl pyrrole derivatives and corresponding 3-pyrryl substituted heterocyclic fulgides:3-pyrryl-ethylidene(isopropylidene)succinic anhydrides have been synthesized and characterized.Their photochromic behavour in several organic solvents were investigated.The coloured form of fulgide Ⅱc,(E)-α-(1,2,4-trimethyl-3-pyrryl)-ethylidene(isopropylidene)succinic anhydride,shows absorption maxmium at 715nm in acetonitrile.It is the longest absorption among the known photochromic fulgides
Nine new 3-acetyl pyrrole derivatives and corresponding 3-pyrryl substituted heterocyclic fulgides:3-pyrryl-ethylidene(isopropylidene)succinic anhydrides have been synthesized and characterized.Their photochromic behavour in several organic solvents were investigated.The coloured form of fulgide Ⅱc,(E)-α-(1,2,4-trimethyl-3-pyrryl)-ethylidene(isopropylidene)succinic anhydride,shows absorption maxmium at 715nm in acetonitrile.It is the longest absorption among the known photochromic fulgides
1993, 4(3): 203-204
Abstract:
Strongly acidic cation exchange resin(001x1,H form)has been successfully used as a catalyst in synthesis of diphenyl N-benzyloxycarbonyl-1-aminobenzylphosphonate,N-benzyloxycarbonyl-1-aminobenzylphenylphosphinic acid and N-p-tolylsulfonyl-1-aminobenzyl phenylphosphinic acid in high yields.
Strongly acidic cation exchange resin(001x1,H form)has been successfully used as a catalyst in synthesis of diphenyl N-benzyloxycarbonyl-1-aminobenzylphosphonate,N-benzyloxycarbonyl-1-aminobenzylphenylphosphinic acid and N-p-tolylsulfonyl-1-aminobenzyl phenylphosphinic acid in high yields.
1993, 4(3): 205-208
Abstract:
The synthesis and phase behavior of a series of 4'-alkyloxy-4-hydroxy biphenyls were discribed.The effects of reaction conditions on the yields of products were investigated.The characterizations of thermotropic liquid crystalline products for the type and thermal properties are discussed through the use of differential scanning calorimetry,polarizing microscopy.
The synthesis and phase behavior of a series of 4'-alkyloxy-4-hydroxy biphenyls were discribed.The effects of reaction conditions on the yields of products were investigated.The characterizations of thermotropic liquid crystalline products for the type and thermal properties are discussed through the use of differential scanning calorimetry,polarizing microscopy.
1993, 4(3): 209-212
Abstract:
The N(b)-bromomethyl derivative (2) of gelsemine,a quaternary ammonium salt,was found to be recalcitrant toward Hofmann type alkaline degradation which has been successful in other cases.Instead,a re-distribution of the N-methyl group took place,giving rise to 3a,1,3b and 3c,in descending order of Rf values.
The N(b)-bromomethyl derivative (2) of gelsemine,a quaternary ammonium salt,was found to be recalcitrant toward Hofmann type alkaline degradation which has been successful in other cases.Instead,a re-distribution of the N-methyl group took place,giving rise to 3a,1,3b and 3c,in descending order of Rf values.
1993, 4(3): 213-214
Abstract:
Four peptides PSPP1,PSPP2,PSPP3 and PSPP4 were purified from the water-extractof Papaver somniferum pollen.Their sequences,with 21,17,13 and 16 amino acid residues respectively,have been determined by Edman degradation-N-terminal dansylation.PSPP2,PSPP3 and PSPP4 were synthesized using solid phase method.The immunopromotive activities of PSPP1,PSPP2,PSPP3,PSPP4 and the initially separated sample PSPP have been also observed by the methods of counting erythrocyte rosette forming cells(ERFC) and T-lymphocyte transformation test in vitro.
Four peptides PSPP1,PSPP2,PSPP3 and PSPP4 were purified from the water-extractof Papaver somniferum pollen.Their sequences,with 21,17,13 and 16 amino acid residues respectively,have been determined by Edman degradation-N-terminal dansylation.PSPP2,PSPP3 and PSPP4 were synthesized using solid phase method.The immunopromotive activities of PSPP1,PSPP2,PSPP3,PSPP4 and the initially separated sample PSPP have been also observed by the methods of counting erythrocyte rosette forming cells(ERFC) and T-lymphocyte transformation test in vitro.
1993, 4(3): 215-216
Abstract:
Photodecarbonylation reaction of acrolein at 193nm was investigated by ab initio molecular orbital method.Our result supports photodecarbonylation mechanisms proposed by Fujimoto,and predicts that the reaction should occur in 8ππ* potentialenergy surface prior to the 1ππ* potential energy surface.
Photodecarbonylation reaction of acrolein at 193nm was investigated by ab initio molecular orbital method.Our result supports photodecarbonylation mechanisms proposed by Fujimoto,and predicts that the reaction should occur in 8ππ* potentialenergy surface prior to the 1ππ* potential energy surface.
1993, 4(3): 217-218
Abstract:
The mechanism of the electron transfer reaction of 1,4-dilithio-tetraphenyl-1,3-butadiene with methyl iodide was studied.
The mechanism of the electron transfer reaction of 1,4-dilithio-tetraphenyl-1,3-butadiene with methyl iodide was studied.
1993, 4(3): 219-220
Abstract:
A new β-dihydroagarofuran alkaloid Ⅰ was isolated from Celastrus angulatus.The structure was established on the basis of 1D and 2D NMR analysis,and x-ray diffraction.
A new β-dihydroagarofuran alkaloid Ⅰ was isolated from Celastrus angulatus.The structure was established on the basis of 1D and 2D NMR analysis,and x-ray diffraction.
1993, 4(3): 221-224
Abstract:
The transmetallation reaction of 4 Schiff base type arylmercury compounds with metallic tin has been carried out in refluxing xylene.It was found that the reaction proceeds in the same manner as that of chloro[2-(phenylazo)phenyl]mercury(Ⅱ)to give dichlorobisaryltin(Ⅳ).The 1H NMR spectra of the products provide evidence for the presence of N→Sn intramolecular coordination.The formation of dichlorobisaryltin(Ⅳ)as a unique product probably arises from the N→Sn intramolecular coordination which results in the increasing of the stability of the molecule.
The transmetallation reaction of 4 Schiff base type arylmercury compounds with metallic tin has been carried out in refluxing xylene.It was found that the reaction proceeds in the same manner as that of chloro[2-(phenylazo)phenyl]mercury(Ⅱ)to give dichlorobisaryltin(Ⅳ).The 1H NMR spectra of the products provide evidence for the presence of N→Sn intramolecular coordination.The formation of dichlorobisaryltin(Ⅳ)as a unique product probably arises from the N→Sn intramolecular coordination which results in the increasing of the stability of the molecule.
1993, 4(3): 225-228
Abstract:
This paper presents the synthesis and structural characterization of asymmetric tripyrrane-containing macrocycle.This macrocycle could be oxidized to the methine bridged,22 π-electron aromatic macrocyclic complexes containing cadmium(Ⅱ),samarium (Ⅲ),europium(Ⅲ)and gadolinium(Ⅲ)by treating with corresponding metal chloride in the presence of air Their structures were characterized by spectral methods.
This paper presents the synthesis and structural characterization of asymmetric tripyrrane-containing macrocycle.This macrocycle could be oxidized to the methine bridged,22 π-electron aromatic macrocyclic complexes containing cadmium(Ⅱ),samarium (Ⅲ),europium(Ⅲ)and gadolinium(Ⅲ)by treating with corresponding metal chloride in the presence of air Their structures were characterized by spectral methods.
1993, 4(3): 229-232
Abstract:
The mixture of fullerene—C60 and —C70 was successfully separated in larger amount by liquid chromatography on graphite column.The column was first eluted with a mixture of hexane and toluene,and then with toluene.The eluates were monitored by UV/visible absorption spectroscopy.Graphite column shows high performance for separation.and much larger quantities of pure C60 can be easily obtained.The synthesis of fullerenes(C60 and C70)in macroscopic quantities[1,2] has stimulated scientists to study on themethod for separating C60 and C70.Because of the poor solubility of fullerenes C60/C70 in most organic solvents,theseparation of C60 and C70 proved to be a challenging task.Most attempts at the separation have used silica and alu-mina as the stationary phase and a mixture of hexane and benzene(or toluene)as the mobile phase[3,5].Fullerenes,however,have only limited solubility in hexane,these separations are usually only achieved by limit-ing the amount of sample to a few milligrams.The hexane-silica technique using phenylglycine based HPLCcolumns appears to offer good separation[6],but only for submilligram amounts. The use of graphite powder as the stationary phase in liquid chromatography is an advanced separation tech-nique for fullerenes C60/C70[7,8].The technique is based on that the fullerene-C60 is different from C60 in the de-gree of electron delocalisation,and C60 is much less diamagnetic than C70.It is expected that the dissimilarity willcause the C60/C70 molecules to exhibit different interactions with graphite,and can be separated from each other onthis basis.
The mixture of fullerene—C60 and —C70 was successfully separated in larger amount by liquid chromatography on graphite column.The column was first eluted with a mixture of hexane and toluene,and then with toluene.The eluates were monitored by UV/visible absorption spectroscopy.Graphite column shows high performance for separation.and much larger quantities of pure C60 can be easily obtained.The synthesis of fullerenes(C60 and C70)in macroscopic quantities[1,2] has stimulated scientists to study on themethod for separating C60 and C70.Because of the poor solubility of fullerenes C60/C70 in most organic solvents,theseparation of C60 and C70 proved to be a challenging task.Most attempts at the separation have used silica and alu-mina as the stationary phase and a mixture of hexane and benzene(or toluene)as the mobile phase[3,5].Fullerenes,however,have only limited solubility in hexane,these separations are usually only achieved by limit-ing the amount of sample to a few milligrams.The hexane-silica technique using phenylglycine based HPLCcolumns appears to offer good separation[6],but only for submilligram amounts. The use of graphite powder as the stationary phase in liquid chromatography is an advanced separation tech-nique for fullerenes C60/C70[7,8].The technique is based on that the fullerene-C60 is different from C60 in the de-gree of electron delocalisation,and C60 is much less diamagnetic than C70.It is expected that the dissimilarity willcause the C60/C70 molecules to exhibit different interactions with graphite,and can be separated from each other onthis basis.
1993, 4(3): 233-234
Abstract:
A europium chelate of 5-chlorosulfoyl-2-thenoyltrifluoroacetone(CTTA)was investigated for precolumn derivatization ofprotein for high performance liquid chromatography.This new label was highlyfluorescent and suitable for time-resolved fluorometric detection.Thedetective limit of protein is less than 0.3ug in sample with a volume of100ul.Theoretically,the new label can also be used in gel electrophoresisand protein blotting.
A europium chelate of 5-chlorosulfoyl-2-thenoyltrifluoroacetone(CTTA)was investigated for precolumn derivatization ofprotein for high performance liquid chromatography.This new label was highlyfluorescent and suitable for time-resolved fluorometric detection.Thedetective limit of protein is less than 0.3ug in sample with a volume of100ul.Theoretically,the new label can also be used in gel electrophoresisand protein blotting.
1993, 4(3): 235-238
Abstract:
Hickman's fast nonadiabatic collision model for the ion-pair formation reaction A+BC→A++BC-was improved,where the classical trajectory has been represented by solution of motion equation UR=-dV(R)/dR,here V(R)is Morse potential.Employing this model to the CS+O2→CS++O2-reaction,a satisfactory agreement with experimental data has been obtained.
Hickman's fast nonadiabatic collision model for the ion-pair formation reaction A+BC→A++BC-was improved,where the classical trajectory has been represented by solution of motion equation UR=-dV(R)/dR,here V(R)is Morse potential.Employing this model to the CS+O2→CS++O2-reaction,a satisfactory agreement with experimental data has been obtained.
1993, 4(3): 239-242
Abstract:
The equilibrium geometries,excitation energies,force constants and vibrational frequencies for the low-ly-ing electronic states X2B1,2A1,2B2 and 2A2 of the AsH2 radical have been calculated at the MRSDCI level witha 3-21G* basis set.Our calculated geometries,excitation ene-gies and vibional frequencies for the X2B1 and 2A1 states are in good agreement with available experimental data.The electronic transition dipole moments,oscillator strengths for the 2A1→X 2B1 and 2A2→X 2B21 transitions,radiative lifetimes for the 2A1 and 2A2 states are calculated based on the MRSDC1 wavefunctions,predicting results in reasonable agreement withavailable experiment.
The equilibrium geometries,excitation energies,force constants and vibrational frequencies for the low-ly-ing electronic states X2B1,2A1,2B2 and 2A2 of the AsH2 radical have been calculated at the MRSDCI level witha 3-21G* basis set.Our calculated geometries,excitation ene-gies and vibional frequencies for the X2B1 and 2A1 states are in good agreement with available experimental data.The electronic transition dipole moments,oscillator strengths for the 2A1→X 2B1 and 2A2→X 2B21 transitions,radiative lifetimes for the 2A1 and 2A2 states are calculated based on the MRSDC1 wavefunctions,predicting results in reasonable agreement withavailable experiment.
1993, 4(3): 243-246
Abstract:
The properties of absorption spectra are presented and the linear correlations of Hammett constants with the 0-0 transition energy(Eo,o)of S1←So,and the ratios of oscillator strength(fa/fe)are used to probe the interactions betwee π-electron of aromatic maerocycles or metal ion of complexes with the substituents on β-position of benzene ring for porphyrin-like maerocyclic compounds
The properties of absorption spectra are presented and the linear correlations of Hammett constants with the 0-0 transition energy(Eo,o)of S1←So,and the ratios of oscillator strength(fa/fe)are used to probe the interactions betwee π-electron of aromatic maerocycles or metal ion of complexes with the substituents on β-position of benzene ring for porphyrin-like maerocyclic compounds
1993, 4(3): 247-250
Abstract:
The formation and breaking of intramolecular hydrogen bonds of bilirubin in CDCl3-DMSO-d6 binary solvent have been investigated by means of NMR spectroscopy.The chemical shifts of protons at dipyrrinone lactam C=Oand N-H,Pyrrole N-H,C-5,C-15 and methylene groups of 8,12-propionic acid side-chains changed markedly as a function of composition of the binary solvent.The hydrogen bond formation is dependent on the conformation of propionic acid side-chains.
The formation and breaking of intramolecular hydrogen bonds of bilirubin in CDCl3-DMSO-d6 binary solvent have been investigated by means of NMR spectroscopy.The chemical shifts of protons at dipyrrinone lactam C=Oand N-H,Pyrrole N-H,C-5,C-15 and methylene groups of 8,12-propionic acid side-chains changed markedly as a function of composition of the binary solvent.The hydrogen bond formation is dependent on the conformation of propionic acid side-chains.
1993, 4(3): 251-254
Abstract:
In this letter the study of Li-doped zinc oxide by electron paramagnetic resonance method is described.A signal observed atg=2.013,g1=1.955 on the degassed sample at 923K was designated toFs+ centers(surface oxygen ion vacancies with a single trapped electron).When the sample was quenched from 1003K into liquid oxygenat 77K under 24 KPa O2,[Li+O-] ion pairs valued at g=2.026 andg=2.003 with superhyperfine constant a=2.0G,which resulted from 7Li nucleus,formed at Li+-substitutional site in ZnO lattice.A probable mechanism of [Li+O-]ion pair formation was proposed.
In this letter the study of Li-doped zinc oxide by electron paramagnetic resonance method is described.A signal observed atg=2.013,g1=1.955 on the degassed sample at 923K was designated toFs+ centers(surface oxygen ion vacancies with a single trapped electron).When the sample was quenched from 1003K into liquid oxygenat 77K under 24 KPa O2,[Li+O-] ion pairs valued at g=2.026 andg=2.003 with superhyperfine constant a=2.0G,which resulted from 7Li nucleus,formed at Li+-substitutional site in ZnO lattice.A probable mechanism of [Li+O-]ion pair formation was proposed.
1993, 4(3): 255-256
Abstract:
The perovskite type of compound [n-C11H23N3]2ZnCl4(abr.C11Zn)exhibits two solid-solid phase transitions at Tc1=298.7 K and Tc2=360.1 K.A temperature dependence study of Raman spectra of C11Zn provides the evidence of occurence of the structural phase transition related to the dynamics of the alkylammonium ions.The room temperature phase is ordered and contains the all-trans alkyl chains.The intermediate temperature phase presents a partial conformational disorder and liquidlike state of all conformational disorder occurs at high-temperature phase.
The perovskite type of compound [n-C11H23N3]2ZnCl4(abr.C11Zn)exhibits two solid-solid phase transitions at Tc1=298.7 K and Tc2=360.1 K.A temperature dependence study of Raman spectra of C11Zn provides the evidence of occurence of the structural phase transition related to the dynamics of the alkylammonium ions.The room temperature phase is ordered and contains the all-trans alkyl chains.The intermediate temperature phase presents a partial conformational disorder and liquidlike state of all conformational disorder occurs at high-temperature phase.
1993, 4(3): 257-258
Abstract:
The equations of the second and third order derivative curves of time with respect to potential for a reversible process in adsorption chronopotentiometry are derived and experimentally verified.
The equations of the second and third order derivative curves of time with respect to potential for a reversible process in adsorption chronopotentiometry are derived and experimentally verified.
1993, 4(3): 259-262
Abstract:
The microphase separation extent of biomedical segmented polyetherurethanes were greatly enhanced due to the presence of sulfoalkyl pendant groups contained in the hard segments,and the hard segments were more orderly aggregated through ionic interaction.
The microphase separation extent of biomedical segmented polyetherurethanes were greatly enhanced due to the presence of sulfoalkyl pendant groups contained in the hard segments,and the hard segments were more orderly aggregated through ionic interaction.
1993, 4(3): 263-264
Abstract:
Simultaneous measurements of surface pressure and surface potential and scanning tunneling microscopy study for N-docosylpyridinium-TCNQ monolayer were carried out.These methods allow us to get more informations on properties of the monolayer.The molecules at the final stage of compression are really in compact stack although a voluminous hydrophilic head exists in the molecule.
Simultaneous measurements of surface pressure and surface potential and scanning tunneling microscopy study for N-docosylpyridinium-TCNQ monolayer were carried out.These methods allow us to get more informations on properties of the monolayer.The molecules at the final stage of compression are really in compact stack although a voluminous hydrophilic head exists in the molecule.
1993, 4(3): 265-268
Abstract:
Studies on the miscibility of PHB/PELA blends showed that PHB and PELA were miscible in amorphous state.The crystallization behavior of PHB in the blend was strongly de-pendent on the addition of PELA component.
Studies on the miscibility of PHB/PELA blends showed that PHB and PELA were miscible in amorphous state.The crystallization behavior of PHB in the blend was strongly de-pendent on the addition of PELA component.
1993, 4(3): 269-272
Abstract:
The poly(β-hydroxybutyrate)/poly(d,1-lactide)(PHB/PLA)blend was found to be immiscible,the melting point and the phase crystallinity of PHB were independent of the blend composition.Comparing with plain PHB,the blend exhibited the crystallization change and a certain improvement of the mechanical property.
The poly(β-hydroxybutyrate)/poly(d,1-lactide)(PHB/PLA)blend was found to be immiscible,the melting point and the phase crystallinity of PHB were independent of the blend composition.Comparing with plain PHB,the blend exhibited the crystallization change and a certain improvement of the mechanical property.
1993, 4(3): 273-274
Abstract:
Ta4(Te2)4Te4I,Mr=2381.90,Monoclinic,C2/c,a=21.987(2),b=6.153(2),c=19.936(3)Å,β=122.42(14),V=2276.7Å3,z=4,Dm=6.8(5)g/cm3,Dc=6.95g/cm3,λ(Mokα)=0.71073Å,μ=354.0cm-1,F(000)=3876,T=296(1)k,R=5.3%,Rw=6.8%,for 1118 unique observed reflections(1>3σ(Ⅰ)).The structure is composed of [Ta4(Te2)4Te4I]∞ chains,which are formed by the four-nuclear butterfly cluster units "Ta4(Te2)4Te4"with the Ⅰ atoms as the bridging atoms between different cluster units.
Ta4(Te2)4Te4I,Mr=2381.90,Monoclinic,C2/c,a=21.987(2),b=6.153(2),c=19.936(3)Å,β=122.42(14),V=2276.7Å3,z=4,Dm=6.8(5)g/cm3,Dc=6.95g/cm3,λ(Mokα)=0.71073Å,μ=354.0cm-1,F(000)=3876,T=296(1)k,R=5.3%,Rw=6.8%,for 1118 unique observed reflections(1>3σ(Ⅰ)).The structure is composed of [Ta4(Te2)4Te4I]∞ chains,which are formed by the four-nuclear butterfly cluster units "Ta4(Te2)4Te4"with the Ⅰ atoms as the bridging atoms between different cluster units.
1993, 4(3): 275-278
Abstract:
Studies on ultrafine particle catalyst have attracted many researchers'attention by its large surface area,higher activity and selectivity[1-3].Based on the mechanism of α-Fe and FexCy as the catalytical active species[4-7] this paper reports for the first time the preparation method of Fe3C ultrafine particle catalyst,from highly dispersed amorphous Fe powder and free carbon.The Fe powder and free carbon,prepared by laser pyrolysis technique,was then treated by washing and heating at high temperature protected with N2.The catalyst prepared under different experimental conditions was characterazed by means of XRD,electronic diffraction and TEM.It shows that the crystlline grain size is in a range of 1-4nm and composed of Fe3C and α-Fe.It has been found that the ultrafine particleironcarbonide catalyst exhibited much higher activity and selectivity to light olefins.At the standard atmosphere and 380℃ reaction temperature,the conversion of CO reached a maximum of 80%.
Studies on ultrafine particle catalyst have attracted many researchers'attention by its large surface area,higher activity and selectivity[1-3].Based on the mechanism of α-Fe and FexCy as the catalytical active species[4-7] this paper reports for the first time the preparation method of Fe3C ultrafine particle catalyst,from highly dispersed amorphous Fe powder and free carbon.The Fe powder and free carbon,prepared by laser pyrolysis technique,was then treated by washing and heating at high temperature protected with N2.The catalyst prepared under different experimental conditions was characterazed by means of XRD,electronic diffraction and TEM.It shows that the crystlline grain size is in a range of 1-4nm and composed of Fe3C and α-Fe.It has been found that the ultrafine particleironcarbonide catalyst exhibited much higher activity and selectivity to light olefins.At the standard atmosphere and 380℃ reaction temperature,the conversion of CO reached a maximum of 80%.
1993, 4(3): 279-280
Abstract:
The IFTs(Interfacial tension)of petroleum carboxylate/alkaline/HPAM(Hydrolyzedpolyacrylamide)flooding system with Daing crude oil and the effects of petroleum carboxylate and alkaline on viscoaity of HPAM solution were studied.There exists remarkable synergism between HPAM and petroleum carboxylate,and the introduction of HPAM into petroleum carboxylate/alkaline system leads the lowering of IFTs against Daqing crude oil,The introduction of petroleum carboxylate into solution of HPAM also leads the decreasing of viscosity,but the extent of viscosity decreasing is much lower than that caused by inorganic salts such as NaCl and CaCl2.
The IFTs(Interfacial tension)of petroleum carboxylate/alkaline/HPAM(Hydrolyzedpolyacrylamide)flooding system with Daing crude oil and the effects of petroleum carboxylate and alkaline on viscoaity of HPAM solution were studied.There exists remarkable synergism between HPAM and petroleum carboxylate,and the introduction of HPAM into petroleum carboxylate/alkaline system leads the lowering of IFTs against Daqing crude oil,The introduction of petroleum carboxylate into solution of HPAM also leads the decreasing of viscosity,but the extent of viscosity decreasing is much lower than that caused by inorganic salts such as NaCl and CaCl2.
1993, 4(3): 281-282
Abstract:
(ηa-C8H5)2CeCl5Mg2(tmed)2 was used as a catalyst to polymerize isoprene,Terminal ends of polyisoprene were identified as -CH2-CH=CH,which indicates that the insertion reaction of the monomer occurred between ηa-allyl and cerium ion and gives a direct evidence for the ηa-allyl mechanism ofconjugated diene polymerzation with rare earth coordination catalysts.
(ηa-C8H5)2CeCl5Mg2(tmed)2 was used as a catalyst to polymerize isoprene,Terminal ends of polyisoprene were identified as -CH2-CH=CH,which indicates that the insertion reaction of the monomer occurred between ηa-allyl and cerium ion and gives a direct evidence for the ηa-allyl mechanism ofconjugated diene polymerzation with rare earth coordination catalysts.
