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1996 Volume 7 Issue 10
1996, 7(10): 879-880
Abstract:
A new metallomicelle, formed by Cu2+ or Zn2- ion and N-tetradecyl-2-(N-2-hydroxyethyl aminomethyl) imidazol in the presence of ceryltrimethylammonium bromide, was found to possess remarkable catalytic activity to the hydrolysis of p-nitrophenyl picolinate.
A new metallomicelle, formed by Cu2+ or Zn2- ion and N-tetradecyl-2-(N-2-hydroxyethyl aminomethyl) imidazol in the presence of ceryltrimethylammonium bromide, was found to possess remarkable catalytic activity to the hydrolysis of p-nitrophenyl picolinate.
1996, 7(10): 881-883
Abstract:
Sixteen new 1, 6-disubstituted fulvenes have been prepared by acylation of cyclopentadienyl sodium and the result of preliminary pharmacological tests showed that several of them have antineoplastic activity.
Sixteen new 1, 6-disubstituted fulvenes have been prepared by acylation of cyclopentadienyl sodium and the result of preliminary pharmacological tests showed that several of them have antineoplastic activity.
1996, 7(10): 884-885
Abstract:
New Schiff base Macrocyclic compound of 2, 3:11, 12:20, 21:29, 30-tetrabenzo-l, 13, 16, 19, 31, 34-hexaoxa-5, 6, 8, 9, 23, 24, 26, 27-octaaza-7, 25-dithione-2, 3:4, 5:9, 10:11, 12:22, 23:27, 28:29, 30-cyclo-[36]ene (thione2B4[36]ene-O6N8) containing THF has been prepared.It crystallizes in the monoclinic, space group P21/n, with parameters a=9.829(5)Å, b=24.23(1)Å, c=10.181(9)Å, β =92.93(5)°, Z=2, V=2422(3)Å3, Dc=1.25gcm-3.Data collection:Rigaku AFC-5R diffractometer, (MoKα, λ =0.71069Å), ω/2θ scans, θmax=25°, empirical absorption correction, 4658 measured reflections, 4387 independent, 1743 observed reflections [I≥ 3σ(I)].The final R=0.056, RW=0.069, S=1.54, (△/σ)max=0.01, △ρmax=0.36eÅ-3.
New Schiff base Macrocyclic compound of 2, 3:11, 12:20, 21:29, 30-tetrabenzo-l, 13, 16, 19, 31, 34-hexaoxa-5, 6, 8, 9, 23, 24, 26, 27-octaaza-7, 25-dithione-2, 3:4, 5:9, 10:11, 12:22, 23:27, 28:29, 30-cyclo-[36]ene (thione2B4[36]ene-O6N8) containing THF has been prepared.It crystallizes in the monoclinic, space group P21/n, with parameters a=9.829(5)Å, b=24.23(1)Å, c=10.181(9)Å, β =92.93(5)°, Z=2, V=2422(3)Å3, Dc=1.25gcm-3.Data collection:Rigaku AFC-5R diffractometer, (MoKα, λ =0.71069Å), ω/2θ scans, θmax=25°, empirical absorption correction, 4658 measured reflections, 4387 independent, 1743 observed reflections [I≥ 3σ(I)].The final R=0.056, RW=0.069, S=1.54, (△/σ)max=0.01, △ρmax=0.36eÅ-3.
1996, 7(10): 886-887
Abstract:
A novel taxol analog with 5/7/6/4 skeleton, taxayuntin 13-[N-benzoyl-(2'R, 3'S)-3'-phenylisoserinate](8) was semisynthesized with an ED50 of 11.0 μg/ml in cytotoxicity assay against KB cell line.
A novel taxol analog with 5/7/6/4 skeleton, taxayuntin 13-[N-benzoyl-(2'R, 3'S)-3'-phenylisoserinate](8) was semisynthesized with an ED50 of 11.0 μg/ml in cytotoxicity assay against KB cell line.
1996, 7(10): 888-891
Abstract:
A salvianolic acid A derivative, hexamethyl ether of salvianolic acid A benzyl ester, was synthesized in fourteen steps.The overall yield was 3.4‰.The compound was identified by 1HNMR and MS.This is the first report of building this structural skeleton.
A salvianolic acid A derivative, hexamethyl ether of salvianolic acid A benzyl ester, was synthesized in fourteen steps.The overall yield was 3.4‰.The compound was identified by 1HNMR and MS.This is the first report of building this structural skeleton.
1996, 7(10): 892-893
Abstract:
Tricyclic compounds (4b-endo) and (4b-exo) are synthesized as the plausible intermediates of the total synhthesis of hainanolide by Lewis acid catalyzed intramolecular Diels-Alder (IMDA) reaction.
Tricyclic compounds (4b-endo) and (4b-exo) are synthesized as the plausible intermediates of the total synhthesis of hainanolide by Lewis acid catalyzed intramolecular Diels-Alder (IMDA) reaction.
1996, 7(10): 894-895
Abstract:
New structural phospholipids 1, 3-cyclic monoalkyl(acyl)-rac-glycerothiophosphates of uridine were synthesized.The strategy for the synthesis is using hexaethylphosphorous triamide, activated by a catalytic amount of iodine, as the phosphorylating reagent.Their structures were confirmed by 1HNMR, 31PNMR, IR and elemental analysis.
New structural phospholipids 1, 3-cyclic monoalkyl(acyl)-rac-glycerothiophosphates of uridine were synthesized.The strategy for the synthesis is using hexaethylphosphorous triamide, activated by a catalytic amount of iodine, as the phosphorylating reagent.Their structures were confirmed by 1HNMR, 31PNMR, IR and elemental analysis.
1996, 7(10): 896-897
Abstract:
—(-)S-Ligustiphenol is a new sesquiterpene compound with antiinflammatory and immunosuppressive activities.The total synthesis of its racemate was carried out by a six-step reaction sequence including bromination of aldehyde, iodination of m-cresol, protection of phenolic hydroxyl, Grignard reaction, aldol condensation, etc.The target compound was characterized by comparing its 1H NMR, MS and IR spectra with natural (-) ligustiphenol.
—(-)S-Ligustiphenol is a new sesquiterpene compound with antiinflammatory and immunosuppressive activities.The total synthesis of its racemate was carried out by a six-step reaction sequence including bromination of aldehyde, iodination of m-cresol, protection of phenolic hydroxyl, Grignard reaction, aldol condensation, etc.The target compound was characterized by comparing its 1H NMR, MS and IR spectra with natural (-) ligustiphenol.
1996, 7(10): 898-899
Abstract:
9-Methyl-6-oxo-5-tosyl-6a,7,8,10a-tetrahydroindeno[2,3,b]indole (Ⅱ) was aromatized by PPE, CF3COOH or BF3·Et2O to furnish the new compound, 9-methyl-5-tosyl-6H-indeno[2,3,b]indole (Ⅷ), involving an unusual"dehydration";the loss of two H's and concomitant exocyclic (to the aromatized carbocycle) removal of the carbonylic oxygen.
9-Methyl-6-oxo-5-tosyl-6a,7,8,10a-tetrahydroindeno[2,3,b]indole (Ⅱ) was aromatized by PPE, CF3COOH or BF3·Et2O to furnish the new compound, 9-methyl-5-tosyl-6H-indeno[2,3,b]indole (Ⅷ), involving an unusual"dehydration";the loss of two H's and concomitant exocyclic (to the aromatized carbocycle) removal of the carbonylic oxygen.
1996, 7(10): 900-901
Abstract:
Under basic conditions 4-(N-methyl-sullamylmethyl)aniline 1 reacted with ethyl 3-bromopyruvate 2 in acetone to give the title compound 5.The structure of 5 was established by MS, IR, 1HNMR and 13CNMR spectra.
Under basic conditions 4-(N-methyl-sullamylmethyl)aniline 1 reacted with ethyl 3-bromopyruvate 2 in acetone to give the title compound 5.The structure of 5 was established by MS, IR, 1HNMR and 13CNMR spectra.
1996, 7(10): 902-904
Abstract:
Treatment of 11-isopropylidene-anti-4, 5-epoxy-endo-tricyclo[6.2.1.02,7] undeca-4, 9-diene-3, 6-dione(6) with methanolic sodium hydroxide results in Favorskii-type ring contraction with concomitant Cope rearrangement and Haller-Bauer cleavage, thereby affording dimethyl-9-isopropxlidene-cis-bicyclo[4.3.0] nonane-(2S)-2, 3-dicarboxylate (7) as the ultimate product.The structure of 7 was confirmed by single crystal X-ray analysis.
Treatment of 11-isopropylidene-anti-4, 5-epoxy-endo-tricyclo[6.2.1.02,7] undeca-4, 9-diene-3, 6-dione(6) with methanolic sodium hydroxide results in Favorskii-type ring contraction with concomitant Cope rearrangement and Haller-Bauer cleavage, thereby affording dimethyl-9-isopropxlidene-cis-bicyclo[4.3.0] nonane-(2S)-2, 3-dicarboxylate (7) as the ultimate product.The structure of 7 was confirmed by single crystal X-ray analysis.
1996, 7(10): 905-906
Abstract:
Ester exchange reaction between the thymidine and N-(O, O-diisopropyl)phosphoryl serine could yield several derivatives of thymidylic acid, including dithymidylic acid.These results might be meaningful to the prebiotic synthesis of macromolecules.
Ester exchange reaction between the thymidine and N-(O, O-diisopropyl)phosphoryl serine could yield several derivatives of thymidylic acid, including dithymidylic acid.These results might be meaningful to the prebiotic synthesis of macromolecules.
1996, 7(10): 907-908
Abstract:
This paper describes the direct oxidation of pyridines to pyridine-N-oxides by means of 30% H2O2 in aq media in the presence of Na2WO4.2H2O as catalyst instead of with per-acids or 30% H2O2 in acetic acid.Good yields were obtained.
This paper describes the direct oxidation of pyridines to pyridine-N-oxides by means of 30% H2O2 in aq media in the presence of Na2WO4.2H2O as catalyst instead of with per-acids or 30% H2O2 in acetic acid.Good yields were obtained.
1996, 7(10): 909-910
Abstract:
A combinatorial cleavage, acidolysis-saponification, after solid phase peptide synthesis on photo-labile resin was stated in present paper.Peptide (Gly-Asp-Ala-Lys-Gly)2 > Lys-OH was liberated with high yield(92.1%) and excellent purity(91.6%) from its protected peptidyl nitro-resin precursor by a new orthorgonal protocol:1) Hi-TFMSA, 2) 0.2N NaOH/90% EtOH.
A combinatorial cleavage, acidolysis-saponification, after solid phase peptide synthesis on photo-labile resin was stated in present paper.Peptide (Gly-Asp-Ala-Lys-Gly)2 > Lys-OH was liberated with high yield(92.1%) and excellent purity(91.6%) from its protected peptidyl nitro-resin precursor by a new orthorgonal protocol:1) Hi-TFMSA, 2) 0.2N NaOH/90% EtOH.
1996, 7(10): 911-912
Abstract:
Two new germacrane sesquiterpenes(1) and (2) were isolated from Ligularia dentata.Their structures were elucidated by spectroscopic methods and 2D-NMR techniques.
Two new germacrane sesquiterpenes(1) and (2) were isolated from Ligularia dentata.Their structures were elucidated by spectroscopic methods and 2D-NMR techniques.
1996, 7(10): 913-914
Abstract:
A new eudesmane sesquiterpene 1β, 4β, 6α, 15-tetrahydroxyeudesmane isolated from Senecio flammeus and its structure determined on the basis of spectral data are reported.
A new eudesmane sesquiterpene 1β, 4β, 6α, 15-tetrahydroxyeudesmane isolated from Senecio flammeus and its structure determined on the basis of spectral data are reported.
1996, 7(10): 915-916
Abstract:
A benzodioxin derivative was isolated in the phytochemical investigation of Ligularia intermedia Nakai.Its structure was elucidated by high field 1H NMR, 13C NMR and DEPT, together with the EI-MS and IR.
A benzodioxin derivative was isolated in the phytochemical investigation of Ligularia intermedia Nakai.Its structure was elucidated by high field 1H NMR, 13C NMR and DEPT, together with the EI-MS and IR.
1996, 7(10): 917-918
Abstract:
Two compounds, 12-deoxyphorbol-13-hexadecanoate 1 and 12-deoxyphorbol-13-acetate 2 were isolated from the roots of Euphorbia fischeriana.Compoound 1 was elucidated as a new diterpenoid.Compound 2 was discovered for the first time from this plant and showed analgesic and sedative activities in preliminary experiment in mice.
Two compounds, 12-deoxyphorbol-13-hexadecanoate 1 and 12-deoxyphorbol-13-acetate 2 were isolated from the roots of Euphorbia fischeriana.Compoound 1 was elucidated as a new diterpenoid.Compound 2 was discovered for the first time from this plant and showed analgesic and sedative activities in preliminary experiment in mice.
1996, 7(10): 919-921
Abstract:
The H-point standard additions method is applied in fluorimetry for determining α-naphthol and β-naphthol simultaneously.When the concentration ratio of α-naphthol to β-naphthol in the sample varies from 40:1 to 1:20, the accuracy and precision of the results are both satisfactory.
The H-point standard additions method is applied in fluorimetry for determining α-naphthol and β-naphthol simultaneously.When the concentration ratio of α-naphthol to β-naphthol in the sample varies from 40:1 to 1:20, the accuracy and precision of the results are both satisfactory.
1996, 7(10): 922-923
Abstract:
A new electrochemical immunoassay based on catalytic conversion of substrate by labeled metal ion and polarographic detection of generated product was developed.In this immunoassay, copper ion was used A catalyst for the conversion of substrate to substitute natural enzyme.Copper ion was labeled to antigens such as Human serum albumin( HSA ), Diphtheria Toxoid ( DT ), Tetanus Toxoid ( TT ) through bifunctional chelating agent diethylenetriamine pentaacetic acid ( DTPA ).After heterogeneous competitive immune reaction, the labeled copper ion was released by acidification, and then catalyzes chemically the conversion of substrate o-phenyldiamine ( OPD ) to electroactive product 2, 3-diaminophenazine ( DAP ).The product DAP was detected by using linearsweep polarography.The sensitivity of the proposed assay for the determination of HSA, DT and TT is superior to those of previous one based on direct detection of the labeled metal ion.
A new electrochemical immunoassay based on catalytic conversion of substrate by labeled metal ion and polarographic detection of generated product was developed.In this immunoassay, copper ion was used A catalyst for the conversion of substrate to substitute natural enzyme.Copper ion was labeled to antigens such as Human serum albumin( HSA ), Diphtheria Toxoid ( DT ), Tetanus Toxoid ( TT ) through bifunctional chelating agent diethylenetriamine pentaacetic acid ( DTPA ).After heterogeneous competitive immune reaction, the labeled copper ion was released by acidification, and then catalyzes chemically the conversion of substrate o-phenyldiamine ( OPD ) to electroactive product 2, 3-diaminophenazine ( DAP ).The product DAP was detected by using linearsweep polarography.The sensitivity of the proposed assay for the determination of HSA, DT and TT is superior to those of previous one based on direct detection of the labeled metal ion.
1996, 7(10): 924-927
Abstract:
In this paper, the singlet and triplet state electron transfer processes between hypocrellin A(HA) and aromatic amines in solvents of various polarity have been studied by fluorescence and time-resolved transient absorption spectra.The results show, in.polar solvent, the quenching of HA fluorescence by aromatic amines results in Stern-Volmer plot, the investigation of transient absorption indicated that triplet-state electron transfer process from 3HA* to the ground-state of amines occured, and the values of the singlet and triplet state electron transfer rate constant were calculated, however in weak polar solvent, only the triplet-triplet absorption of HA was observed.
In this paper, the singlet and triplet state electron transfer processes between hypocrellin A(HA) and aromatic amines in solvents of various polarity have been studied by fluorescence and time-resolved transient absorption spectra.The results show, in.polar solvent, the quenching of HA fluorescence by aromatic amines results in Stern-Volmer plot, the investigation of transient absorption indicated that triplet-state electron transfer process from 3HA* to the ground-state of amines occured, and the values of the singlet and triplet state electron transfer rate constant were calculated, however in weak polar solvent, only the triplet-triplet absorption of HA was observed.
1996, 7(10): 928-930
Abstract:
The chemical oscillating reactions in KMnO4-NH2CH2COOH-H3-PO4 CSTR system in the presence and absence of Ag+ have been studied.The reaction conditions and phase diagrams have been determined.Some effects on the oscillation have been studied.The stabilization of colloidal particles of MnO2 by PO43- has been investigated.The roles of Ag+ in the above reactions have also been studied.
The chemical oscillating reactions in KMnO4-NH2CH2COOH-H3-PO4 CSTR system in the presence and absence of Ag+ have been studied.The reaction conditions and phase diagrams have been determined.Some effects on the oscillation have been studied.The stabilization of colloidal particles of MnO2 by PO43- has been investigated.The roles of Ag+ in the above reactions have also been studied.
1996, 7(10): 931-934
Abstract:
The spectroscopic properties and photoinduced electron transfer process have been studied in zinc phthalocyanine-viologen system with bisphenol A (ZnPcAV2+).It was found that the excited singlet state of zinc phthalocyanine moiety is quenched and the fluorescence lifetime is reduced by the linked viologen.Nanosecond laser photolysis studies showed that intramolecular quenching of the excited triplet state of zinc phthalocyanine moiety by the attached viologen occurred giving reduced viologen radical ion (V+) that survived over 50μs.
The spectroscopic properties and photoinduced electron transfer process have been studied in zinc phthalocyanine-viologen system with bisphenol A (ZnPcAV2+).It was found that the excited singlet state of zinc phthalocyanine moiety is quenched and the fluorescence lifetime is reduced by the linked viologen.Nanosecond laser photolysis studies showed that intramolecular quenching of the excited triplet state of zinc phthalocyanine moiety by the attached viologen occurred giving reduced viologen radical ion (V+) that survived over 50μs.
1996, 7(10): 935-938
Abstract:
The influence of overcoating layers of dialkylglycerylether-β-glucosides(A), 1,2-O-dialkylglycerylethers(B) and.arachidic acid (C20) on the fluorescence of the squaraine dye(SQ) and C20 mixed film were investigated by fluorescence and time-resolved fluorescence measurements.An apparent increase in fluorescence intensity for three layer mixed film of SQ and C20 were obtained by overcoating A in comparison with the small change fluorescence intensity for SQ dye mixed film by overcoating B or C20.
The influence of overcoating layers of dialkylglycerylether-β-glucosides(A), 1,2-O-dialkylglycerylethers(B) and.arachidic acid (C20) on the fluorescence of the squaraine dye(SQ) and C20 mixed film were investigated by fluorescence and time-resolved fluorescence measurements.An apparent increase in fluorescence intensity for three layer mixed film of SQ and C20 were obtained by overcoating A in comparison with the small change fluorescence intensity for SQ dye mixed film by overcoating B or C20.
1996, 7(10): 939-941
Abstract:
The charge isomer fraction(PI 5.9) of the Cu.Zn SOD from duck red blood cell has been crystallized around neutral pH and low ionic strength at 297K.The crystals belong to the trigonel space group P3221, with unit cell a=125.lÅ;, c=163.3Å and γ=120°.The duck SOD shows a novel packing arrangement consisting of supramolecular double-helix, with 922/972 non-crystallographic border group symmetry in the crystal.
The charge isomer fraction(PI 5.9) of the Cu.Zn SOD from duck red blood cell has been crystallized around neutral pH and low ionic strength at 297K.The crystals belong to the trigonel space group P3221, with unit cell a=125.lÅ;, c=163.3Å and γ=120°.The duck SOD shows a novel packing arrangement consisting of supramolecular double-helix, with 922/972 non-crystallographic border group symmetry in the crystal.
1996, 7(10): 942-943
Abstract:
Novel ordered structure was detected in atactic polystyrene(aPS) formed from aPS/CS2 gel, the ordered structure is constructed through stacks of stereoregular segments by accepting TTGG type conformation.Another anomalous phenomenon was that many particles with different shape and size formed on surface of the film, these were some special aggregates with more ordered structure.
Novel ordered structure was detected in atactic polystyrene(aPS) formed from aPS/CS2 gel, the ordered structure is constructed through stacks of stereoregular segments by accepting TTGG type conformation.Another anomalous phenomenon was that many particles with different shape and size formed on surface of the film, these were some special aggregates with more ordered structure.
1996, 7(10): 944-947
Abstract:
The fluorescence from azobenzene (AB) molecule incorporated into water-swollen Nafion in acid form was observed at room temperature for the first time.The incorporation process was investigated by UV absorption.The plot of the concentration of AB in Nafion vs.the soaking time shows that the adsorption process is diffusion-controlled, and the apparent diffusion coefficient (D) was determined to be 7.6×1010cm2s-1.These results are attributed to the fact that AB molecules are located in the fluorocarbon/water interface of the Nafion membranes and are protonated.In methanol-swollen Nafion membranes, AB fails to fluoresce because it is located at the methanol pool enclosed by the cluster networks.
The fluorescence from azobenzene (AB) molecule incorporated into water-swollen Nafion in acid form was observed at room temperature for the first time.The incorporation process was investigated by UV absorption.The plot of the concentration of AB in Nafion vs.the soaking time shows that the adsorption process is diffusion-controlled, and the apparent diffusion coefficient (D) was determined to be 7.6×1010cm2s-1.These results are attributed to the fact that AB molecules are located in the fluorocarbon/water interface of the Nafion membranes and are protonated.In methanol-swollen Nafion membranes, AB fails to fluoresce because it is located at the methanol pool enclosed by the cluster networks.
1996, 7(10): 948-950
Abstract:
The conformation of amphiphilic branch chain in acrylamide-poly(oxyethylene alkyl ether)acrylate copolymers on interface was investigated by static laser light scattering and X-ray photoelectron spectroscopy.The results show that the conformation of branch chain alters with copolymer structure.
The conformation of amphiphilic branch chain in acrylamide-poly(oxyethylene alkyl ether)acrylate copolymers on interface was investigated by static laser light scattering and X-ray photoelectron spectroscopy.The results show that the conformation of branch chain alters with copolymer structure.
1996, 7(10): 951-953
Abstract:
The variation of the I1/I3 ratio of the fluorescence of pyrene in polystyrene-based quaternary ammonium salt (PA) and sodium carboxymethylamylose (NaCMA) aqueous solutions was measured as a function of sodium perfluorooctanoate (SPFO) concentration.Association of the anionic fluorocarbon surfactant with cationic polyelectrolyte (PA) to form mixed micelles occurred at the surfactant concentrations far below its normal critical concentration, while no interaction between SPFO and anionic polyelectrolyte (NaCMA) was detected.The driving force for the formation of mixed micelles of SPFO and PA is electrostatic interactions.
The variation of the I1/I3 ratio of the fluorescence of pyrene in polystyrene-based quaternary ammonium salt (PA) and sodium carboxymethylamylose (NaCMA) aqueous solutions was measured as a function of sodium perfluorooctanoate (SPFO) concentration.Association of the anionic fluorocarbon surfactant with cationic polyelectrolyte (PA) to form mixed micelles occurred at the surfactant concentrations far below its normal critical concentration, while no interaction between SPFO and anionic polyelectrolyte (NaCMA) was detected.The driving force for the formation of mixed micelles of SPFO and PA is electrostatic interactions.
1996, 7(10): 954-955
Abstract:
A series of new binary rare earth oxyfluoride ( Sm2O3-LaF3 ) catalysts have been developed for ODE reaction.High C2H4 selectivity (91.5%) with C2H6 conversion 21.7% was achieved on the catalyst Sm2O3/LaF3 with molar ratio 1/1 at 700℃.The addition of 16.7 mol % BaF2 into Sm2O3/LaF3(1/1 in mol) led to the increase of C2H6 conversion from 21.7% to 40.8%, however, the change of ethene seletivity was not apparent (from 91.5% to 88.0%).
A series of new binary rare earth oxyfluoride ( Sm2O3-LaF3 ) catalysts have been developed for ODE reaction.High C2H4 selectivity (91.5%) with C2H6 conversion 21.7% was achieved on the catalyst Sm2O3/LaF3 with molar ratio 1/1 at 700℃.The addition of 16.7 mol % BaF2 into Sm2O3/LaF3(1/1 in mol) led to the increase of C2H6 conversion from 21.7% to 40.8%, however, the change of ethene seletivity was not apparent (from 91.5% to 88.0%).
1996, 7(10): 956-959
Abstract:
A Novel type single-component catalyst in which small amounts of nickel of ruthenium supported on sepiolite was found to be a very efficient methanation catalyst for carbon dioxide at high space velocity.
A Novel type single-component catalyst in which small amounts of nickel of ruthenium supported on sepiolite was found to be a very efficient methanation catalyst for carbon dioxide at high space velocity.
1996, 7(10): 960-961
Abstract:
Nanometer oxide LaMnO3+λ and its counterparts with large particle size were comparatively studied for total oxidation of methane.XPS, TPR and nonstoichiometric oxygen(λ) analysis results identify that the nanometer oxide contains more high valence cations, to which the adjacent lattice oxygen are responsible for total oxidation of methane at low temperature.
Nanometer oxide LaMnO3+λ and its counterparts with large particle size were comparatively studied for total oxidation of methane.XPS, TPR and nonstoichiometric oxygen(λ) analysis results identify that the nanometer oxide contains more high valence cations, to which the adjacent lattice oxygen are responsible for total oxidation of methane at low temperature.
1996, 7(10): 962-964
Abstract:
A methane monooxygenase-like dinuclear complex of iron (Ⅲ) with a chiral heptadentate ligand has been synthesed and tested for catalytic ability for asymmetric epoxidation of styrene with iodosylbenzene.The results show that the complex exhibits many qualitative features, such as electronic spectrum, catalytic behavior, and asymmetric induction similar to those of methane monooxygenase and catalyzes styrene epoxidation to R-(+)-styrene oxide in 9.3% yield and 72.9% optical yield.
A methane monooxygenase-like dinuclear complex of iron (Ⅲ) with a chiral heptadentate ligand has been synthesed and tested for catalytic ability for asymmetric epoxidation of styrene with iodosylbenzene.The results show that the complex exhibits many qualitative features, such as electronic spectrum, catalytic behavior, and asymmetric induction similar to those of methane monooxygenase and catalyzes styrene epoxidation to R-(+)-styrene oxide in 9.3% yield and 72.9% optical yield.
1996, 7(10): 965-966
Abstract:
In situ confocal microprobe Raman spectroscopy results showed that O22-, O2- and O2δ- (0 <δ< 1) adspecies formed on the O2 pretreated cerium oxide sample when the temperature was below 423 K.At 1023 K, only CeO2 F2g peak (at 449 cm-1) and O2- species (at 1159 cm-1) were observed on the surface.The reactivity of methane with the oxygen species was lower than that of ethane with the oxygen species.
In situ confocal microprobe Raman spectroscopy results showed that O22-, O2- and O2δ- (0 <δ< 1) adspecies formed on the O2 pretreated cerium oxide sample when the temperature was below 423 K.At 1023 K, only CeO2 F2g peak (at 449 cm-1) and O2- species (at 1159 cm-1) were observed on the surface.The reactivity of methane with the oxygen species was lower than that of ethane with the oxygen species.
1996, 7(10): 967-968
Abstract:
The Infrared spectea of 6Li2CO3, 7Li2CO3, 6Li2SO4, and 7Li2SO4 were studied.The isotopic shift of the vibrational frequency for 6Li-O and 7Li-O bonds amounts to 4.5-7.8 % for the carbonate and 9.5-11.6% for the sulfate.
The Infrared spectea of 6Li2CO3, 7Li2CO3, 6Li2SO4, and 7Li2SO4 were studied.The isotopic shift of the vibrational frequency for 6Li-O and 7Li-O bonds amounts to 4.5-7.8 % for the carbonate and 9.5-11.6% for the sulfate.
1996, 7(10): 969-972
Abstract:
Isotopic ratio measurement was made for gadolinium, utilizing the bias correction facor of cerium and europium for the same mass spectrometer.The atomic weight found from the raw data is Ar(Gd)=157.2473(2).However, the application of the method of double substitute calibration results in Ar(Gd)=157.2526(10), both on 2σ basis.For dysprosium and erbium, the same method yields Ar(Dy)=162.4993(10) and Ar(Er)=167.2611(12).
Isotopic ratio measurement was made for gadolinium, utilizing the bias correction facor of cerium and europium for the same mass spectrometer.The atomic weight found from the raw data is Ar(Gd)=157.2473(2).However, the application of the method of double substitute calibration results in Ar(Gd)=157.2526(10), both on 2σ basis.For dysprosium and erbium, the same method yields Ar(Dy)=162.4993(10) and Ar(Er)=167.2611(12).
