Login In
1995 Volume 6 Issue 1
1995, 6(1): 1-4
Abstract:
A magnesium oxide suppported-polytitazane-platinum complex has been prepared and used to catalyze the hydrogenation of dicyclopentadiene.This complex was very active and stable in the reaction.Dicyclopentadiene could be completely hydrogenated to tricyclo[5.2.1.02,6]decane in 100% yield at 60℃ and under atmospheric hydrogen pressure.
A magnesium oxide suppported-polytitazane-platinum complex has been prepared and used to catalyze the hydrogenation of dicyclopentadiene.This complex was very active and stable in the reaction.Dicyclopentadiene could be completely hydrogenated to tricyclo[5.2.1.02,6]decane in 100% yield at 60℃ and under atmospheric hydrogen pressure.
1995, 6(1): 5-8
Abstract:
Heterocyclic ketene aminals 1 or 2 react with dichlorocarbene to give the formyl substituted heterocyhc ketene aminals 3 or 4 through the carbene insertion reaction of the α-C-H.
Heterocyclic ketene aminals 1 or 2 react with dichlorocarbene to give the formyl substituted heterocyhc ketene aminals 3 or 4 through the carbene insertion reaction of the α-C-H.
1995, 6(1): 9-12
Abstract:
Abstract The excellent enantioselectivity with o.p.>99% in asymmetric borane reduction of acetophenone catalyzed by (4S,5R) 4,5-diphenyl-1,3,2-oxazaborolidine has been achieved via the important modification of the reaction conditions.
Abstract The excellent enantioselectivity with o.p.>99% in asymmetric borane reduction of acetophenone catalyzed by (4S,5R) 4,5-diphenyl-1,3,2-oxazaborolidine has been achieved via the important modification of the reaction conditions.
1995, 6(1): 13-16
Abstract:
A facile,novel and one-pot method for the preparation of 3-phenyl-1H-lndazole derivatives in moderate yields by cyclization of the ortho-substituted benzophenone hydrazones in the presence of polyphosphoric acid (PPA) is reported.
A facile,novel and one-pot method for the preparation of 3-phenyl-1H-lndazole derivatives in moderate yields by cyclization of the ortho-substituted benzophenone hydrazones in the presence of polyphosphoric acid (PPA) is reported.
1995, 6(1): 17-18
Abstract:
Abstract A new type of photographic spectral sensitizer containing silicon-carbon double bond is reported.The application tests show that the dye has excellent sensitivity in silver iodobromide emulsion and that the sensitivity maximum (Smax) of emulsion sensitized by the dye gives a hypsochromic shift about 70nm as compared with the absorption maximum (λmax) of the dye in methanol.This phenomenon differs entirely from typical photographic spectral sensitizing dye.
Abstract A new type of photographic spectral sensitizer containing silicon-carbon double bond is reported.The application tests show that the dye has excellent sensitivity in silver iodobromide emulsion and that the sensitivity maximum (Smax) of emulsion sensitized by the dye gives a hypsochromic shift about 70nm as compared with the absorption maximum (λmax) of the dye in methanol.This phenomenon differs entirely from typical photographic spectral sensitizing dye.
1995, 6(1): 19-22
Abstract:
N-(1-oxo-4-carbonyl-2,6,7-trioxa-1-phosphabicyclo[2.2.2] octane)-N'-aryl thioureas(4) were synthesized in this paper.(4) reacted with AgNO3-H2O and chloroacetyl chloride to afford the corresponding urea derivatives (5) and cyclired products (10),respectively.The mechanism of desulphurisation of (4) has also been studied.
N-(1-oxo-4-carbonyl-2,6,7-trioxa-1-phosphabicyclo[2.2.2] octane)-N'-aryl thioureas(4) were synthesized in this paper.(4) reacted with AgNO3-H2O and chloroacetyl chloride to afford the corresponding urea derivatives (5) and cyclired products (10),respectively.The mechanism of desulphurisation of (4) has also been studied.
1995, 6(1): 23-26
Abstract:
For the synthesis of O-monosaccharidyl-methoxycarbonylphosphonamidates,a new method in which Arbuzov reaction of monosaccharidylphosphoramidite with methyl chloroformate is the key step,is reported.Thus,a number of novel O-monosaccharidyl-methoxycarbonyiphosphonamidates were obtained successfully.
For the synthesis of O-monosaccharidyl-methoxycarbonylphosphonamidates,a new method in which Arbuzov reaction of monosaccharidylphosphoramidite with methyl chloroformate is the key step,is reported.Thus,a number of novel O-monosaccharidyl-methoxycarbonyiphosphonamidates were obtained successfully.
1995, 6(1): 27-30
Abstract:
The photochemical reactions of several substituted phenyl phenylacetates incorporated in the cavities of α-and β-cyclodextrins and in organic solvents were investigated.Photolysis of these esters in organic solutions results in both photo-Fries rearrangement and photodecarbonylation products.However,the esters included in cyclodextrin cavities almost exclusively undergo photo-Fries reactions.Furthermore,in the photo-Fries reactions of the inclusion complex the ratios of ortho to para rearrangement products are evidently increased compared with those in organic solutions.Those are good examples for using cyclodextrins to control the selectivity in photochemical reactions.
The photochemical reactions of several substituted phenyl phenylacetates incorporated in the cavities of α-and β-cyclodextrins and in organic solvents were investigated.Photolysis of these esters in organic solutions results in both photo-Fries rearrangement and photodecarbonylation products.However,the esters included in cyclodextrin cavities almost exclusively undergo photo-Fries reactions.Furthermore,in the photo-Fries reactions of the inclusion complex the ratios of ortho to para rearrangement products are evidently increased compared with those in organic solutions.Those are good examples for using cyclodextrins to control the selectivity in photochemical reactions.
1995, 6(1): 31-34
Abstract:
In aqueous organic solvents perfluoroalkyl 2-naphthoates (NpFCn) with long fluorocarbon chain show strong excimer fluorescence.Excitation of NpFCn in the mixed solution of NpFCn and 9-anthrylmethyl perf1uoroalkanoates (AnFCn) results in strong emission of AnFCn.These observations suggest that hydrophobic interactions force fluorocarbon molecules to form aggregates.
In aqueous organic solvents perfluoroalkyl 2-naphthoates (NpFCn) with long fluorocarbon chain show strong excimer fluorescence.Excitation of NpFCn in the mixed solution of NpFCn and 9-anthrylmethyl perf1uoroalkanoates (AnFCn) results in strong emission of AnFCn.These observations suggest that hydrophobic interactions force fluorocarbon molecules to form aggregates.
1995, 6(1): 35-38
Abstract:
A series of pH-and temperature-sensitive hydrogels were prepared.These gels do not swell at 37℃ and pH 1.4 but swell at 37℃ and pH 7.4.When papain was loaded in these gels,it can be released at 37℃ and pH 7.4 in a high percentage without any loss of activity.
A series of pH-and temperature-sensitive hydrogels were prepared.These gels do not swell at 37℃ and pH 1.4 but swell at 37℃ and pH 7.4.When papain was loaded in these gels,it can be released at 37℃ and pH 7.4 in a high percentage without any loss of activity.
1995, 6(1): 39-40
Abstract:
A new cyclopeptide glabrin A has been isolated from the seeds of Annona glabra.Its structure was elucidated by 2D-NMR and FAB-MS.
A new cyclopeptide glabrin A has been isolated from the seeds of Annona glabra.Its structure was elucidated by 2D-NMR and FAB-MS.
1995, 6(1): 41-44
Abstract:
Coniselin,a new natural compound,was isolated from the roots of Coniselium Vaqinatum Thell.Its structure was elucidated by means of spectroscopic analysis (UV,IR,MS,NMR,DEPT) and confirmed by total synthesis.
Coniselin,a new natural compound,was isolated from the roots of Coniselium Vaqinatum Thell.Its structure was elucidated by means of spectroscopic analysis (UV,IR,MS,NMR,DEPT) and confirmed by total synthesis.
1995, 6(1): 45-48
Abstract:
Muricatalin (1),a new polyketide (acetogenin) has been isolated from Annona muricata L.Its structure and relative stereochemistry were elucidated on the basis of the spectral analyses of 1 and its derivatives,the acetate (2) and the mesitoate (3)
Muricatalin (1),a new polyketide (acetogenin) has been isolated from Annona muricata L.Its structure and relative stereochemistry were elucidated on the basis of the spectral analyses of 1 and its derivatives,the acetate (2) and the mesitoate (3)
1995, 6(1): 49-52
Abstract:
Dynamic oscillographic analysis means the combination of flow injection technique with oscillographic analysis,and oscillographic determination is carried out in continuously flowing solution.Oscillograms obtained in this way have good stability and high reproducibility.Thus,oscillographic determination method will become really feasible analytical method.
Dynamic oscillographic analysis means the combination of flow injection technique with oscillographic analysis,and oscillographic determination is carried out in continuously flowing solution.Oscillograms obtained in this way have good stability and high reproducibility.Thus,oscillographic determination method will become really feasible analytical method.
1995, 6(1): 53-54
Abstract:
Two new substituted chiral polysiloxanes were synthesized by the reaction of polymethylhydrosiloxane with chiral moieties containing alkenes derived from D-tartaric acid and L-phenylalanine.The primary GC characteristics of the two phases were also determined.
Two new substituted chiral polysiloxanes were synthesized by the reaction of polymethylhydrosiloxane with chiral moieties containing alkenes derived from D-tartaric acid and L-phenylalanine.The primary GC characteristics of the two phases were also determined.
1995, 6(1): 55-58
Abstract:
The in vitro metabolism o.butylphthalide (HBP) by rat liver microsomes was studied in this paper.Capillary GC/MS and BSTFA/1%TMCS derivatization were used for the separation and structure identification of the six metabolites.3-Hydroxylation and r-hydroxylation have been proved to be the main metabolism pathways of HBP by rat liver microsomes.
The in vitro metabolism o.butylphthalide (HBP) by rat liver microsomes was studied in this paper.Capillary GC/MS and BSTFA/1%TMCS derivatization were used for the separation and structure identification of the six metabolites.3-Hydroxylation and r-hydroxylation have been proved to be the main metabolism pathways of HBP by rat liver microsomes.
1995, 6(1): 59-62
Abstract:
After the electron transfers from the metal electrode to the Fe3+(H2O)6 ion,the free energy of activation of this electron transfer reaction is calculated,then using the transition probability which is calculated by the perturbed degeneration theory and the Fermi golden rule,the rate constant is gotten.Compared with the experimental results,it is satisfactory.
After the electron transfers from the metal electrode to the Fe3+(H2O)6 ion,the free energy of activation of this electron transfer reaction is calculated,then using the transition probability which is calculated by the perturbed degeneration theory and the Fermi golden rule,the rate constant is gotten.Compared with the experimental results,it is satisfactory.
1995, 6(1): 63-66
Abstract:
A two-electron irreversible adsorptive reduction peak was observed for the water-soluble ytterbium complex by cyclic voltammetry at mercury electrode.At the surface of mercury electrode,the Yb-TPPS complex is adsorbed by the porphyrin ring,and the ytterbium ion is sitting over the porphyrin plane.The centers of adsorption and the redox reaction for the Yb-TPPS complex are all dependent on the porphyrin ring.The Yb3+ ions do not take part in the electrochemical processes.After reduction,the ytterbium porphyrin complex is very unstable and disintegrates completely.
A two-electron irreversible adsorptive reduction peak was observed for the water-soluble ytterbium complex by cyclic voltammetry at mercury electrode.At the surface of mercury electrode,the Yb-TPPS complex is adsorbed by the porphyrin ring,and the ytterbium ion is sitting over the porphyrin plane.The centers of adsorption and the redox reaction for the Yb-TPPS complex are all dependent on the porphyrin ring.The Yb3+ ions do not take part in the electrochemical processes.After reduction,the ytterbium porphyrin complex is very unstable and disintegrates completely.
1995, 6(1): 67-70
Abstract:
The oxidation of iodide by persulfate was studied in the w/o microemulsion formed by mixture of anionic(AOT) and nonionic(NP-6) surfactant,water and heptane.The reaction rate is appreciably higher in a microemulsion formed solely by AOT than that in a conventional aqueous medium.The incorporation of nonionic surfactant deteriorates the catalytic effect of the microemulsion.
The oxidation of iodide by persulfate was studied in the w/o microemulsion formed by mixture of anionic(AOT) and nonionic(NP-6) surfactant,water and heptane.The reaction rate is appreciably higher in a microemulsion formed solely by AOT than that in a conventional aqueous medium.The incorporation of nonionic surfactant deteriorates the catalytic effect of the microemulsion.
1995, 6(1): 71-74
Abstract:
Abstract Metal atoms of Pd and Cu produced by coevaporation in a metal atom reactor was solvated at low temperature.These solvated metal atoms were immobilized in the polymer pore structure for preparing Pd-Cu bimetallic cluster catalyst.XPS measurements showed that both Pd and Cu were in a zero-valent state.TEM and XRD results indicated that the Pd-Cu cluster particles were very small.Catalytic tests showed that these catalysts are very active for 4-methyl-3-penten-2-one hydrogenation.
Abstract Metal atoms of Pd and Cu produced by coevaporation in a metal atom reactor was solvated at low temperature.These solvated metal atoms were immobilized in the polymer pore structure for preparing Pd-Cu bimetallic cluster catalyst.XPS measurements showed that both Pd and Cu were in a zero-valent state.TEM and XRD results indicated that the Pd-Cu cluster particles were very small.Catalytic tests showed that these catalysts are very active for 4-methyl-3-penten-2-one hydrogenation.
1995, 6(1): 75-78
Abstract:
Abstract A systematic method for studying the self-sustained surface chemical oscillation of the gas-solid catalytic reaction is suggested in this paper.It includcs:(1) the technique of constant temperature,TP-TR,S-TR,(2) the proposed mechanism of the reaction,(3)the mathematical simulation of the reaction and self-susatained surface chemical oscillation.The computed curves coincide with the experimental ones.This result shows that the systematic methods suggested in this paper is feasible.
Abstract A systematic method for studying the self-sustained surface chemical oscillation of the gas-solid catalytic reaction is suggested in this paper.It includcs:(1) the technique of constant temperature,TP-TR,S-TR,(2) the proposed mechanism of the reaction,(3)the mathematical simulation of the reaction and self-susatained surface chemical oscillation.The computed curves coincide with the experimental ones.This result shows that the systematic methods suggested in this paper is feasible.
1995, 6(1): 79-82
Abstract:
XPS,ESR and Mossbauer spectroscopic investigations of iron in Fe-ZSM-5 zeolite show an interaction between adsorbed ethylbenzene(EB) and Fe(Ⅲ) in framework of the zeolite,which causes changes of Fe(2P) binding energy,Mossbauer parameters and ESR signal of framework Fe(Ⅲ) in the zeolite and should be responsible for high catalytic activity of ethylbenzene dehydrogenation over FeZSM-5 catalysts.
XPS,ESR and Mossbauer spectroscopic investigations of iron in Fe-ZSM-5 zeolite show an interaction between adsorbed ethylbenzene(EB) and Fe(Ⅲ) in framework of the zeolite,which causes changes of Fe(2P) binding energy,Mossbauer parameters and ESR signal of framework Fe(Ⅲ) in the zeolite and should be responsible for high catalytic activity of ethylbenzene dehydrogenation over FeZSM-5 catalysts.
1995, 6(1): 83-86
Abstract:
Abstract In this letter,the preparation of three ZrO2 phases has been briefly described and their catalytic results have been presented for CO hydrogenation to olefin.These catalysts had a good selectivity for light olefin.Monoclinic ZrO2 catalyst had a high selectivity for isobutene,while the other phase catalysts had not.
Abstract In this letter,the preparation of three ZrO2 phases has been briefly described and their catalytic results have been presented for CO hydrogenation to olefin.These catalysts had a good selectivity for light olefin.Monoclinic ZrO2 catalyst had a high selectivity for isobutene,while the other phase catalysts had not.
1995, 6(1): 87-90
Abstract:
The synthesis and properties of the title complex CH3OCOCH2CH2SnCl3·2-HOC6H4CH=NC6H4-3'-CH3 are described.It crystallizes from benzene in the monoclinic space group P21/n with unit cell dimensions a=10.326(3),b=6.815(8),c=12.931(6) Å,β=111.52(3)°,V=2088.7(1)Å 3,Z=4,F(000)=1040,μ=16.31 cm-1,Dc=l.67g/cm3 final R factor is 0.037 for 3177 observed reflections,I≥3σ( Io).The tin atom in the structure of the complex exists in a distored octahedral geometry defined by three Cl atoms,the C and O atoms of a chelating methoxycarbonylethyl group as well as an O atom derived from the Schiff base ligand.
The synthesis and properties of the title complex CH3OCOCH2CH2SnCl3·2-HOC6H4CH=NC6H4-3'-CH3 are described.It crystallizes from benzene in the monoclinic space group P21/n with unit cell dimensions a=10.326(3),b=6.815(8),c=12.931(6) Å,β=111.52(3)°,V=2088.7(1)Å 3,Z=4,F(000)=1040,μ=16.31 cm-1,Dc=l.67g/cm3 final R factor is 0.037 for 3177 observed reflections,I≥3σ( Io).The tin atom in the structure of the complex exists in a distored octahedral geometry defined by three Cl atoms,the C and O atoms of a chelating methoxycarbonylethyl group as well as an O atom derived from the Schiff base ligand.
1995, 6(1): 91-92
Abstract:
Reactions of [NH4]2MoO2S2,CuI and PPh3 in Py produced mixed-metal cluster [MoOS3Cu2(Py)2(PPh3)2],which crystallizes in the monoclinic,space group P21/a with a=18.149(4),b=10.044(3),c=25.171(7)Å,β=107.45(2) °,V=4377(2)Å3,Z=4,Dx=1.54,R=0.040,Rw=0.049.The results of structure determination show that the central unit of the cluster compound is composed of three metal and three sulfur atoms.
Reactions of [NH4]2MoO2S2,CuI and PPh3 in Py produced mixed-metal cluster [MoOS3Cu2(Py)2(PPh3)2],which crystallizes in the monoclinic,space group P21/a with a=18.149(4),b=10.044(3),c=25.171(7)Å,β=107.45(2) °,V=4377(2)Å3,Z=4,Dx=1.54,R=0.040,Rw=0.049.The results of structure determination show that the central unit of the cluster compound is composed of three metal and three sulfur atoms.
1995, 6(1): 93-94
Abstract:
Abstract Temperature dependence of C60 solubility in four organic solvents above room temperature was investigated.It is found that the solubilities decrease with increase in temperature in hexane,toluene and xylene while it increases in cyclohexanc.Least square fit gives the heat of solution of C60 in hexane,toluene,xylene and cyclohexane as-6.0,-9.8,-9.1 and 48.2 KJ/mol respectively.
Abstract Temperature dependence of C60 solubility in four organic solvents above room temperature was investigated.It is found that the solubilities decrease with increase in temperature in hexane,toluene and xylene while it increases in cyclohexanc.Least square fit gives the heat of solution of C60 in hexane,toluene,xylene and cyclohexane as-6.0,-9.8,-9.1 and 48.2 KJ/mol respectively.
