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1996 Volume 7 Issue 4
1996, 7(4): 299-300
Abstract:
A new chiral phosphine compound:1,4:3,6-dianhydro-2-O-p-toluene sulfonyl-5-deoxy-5-diphenylphosphino-L-iditol was synthesized using D-sorbitol as starting material,and characterized by elemental analysis,1H NMR,31P NMR,and MS.
A new chiral phosphine compound:1,4:3,6-dianhydro-2-O-p-toluene sulfonyl-5-deoxy-5-diphenylphosphino-L-iditol was synthesized using D-sorbitol as starting material,and characterized by elemental analysis,1H NMR,31P NMR,and MS.
1996, 7(4): 301-302
Abstract:
The halogenation of (Z)-β-Trifluoroacetylvinyltelluride 1 leads to the unexpected pure (E)-β-trifluoroacetylvinyl halides 3,which are allowed to react with organozinc reagents 4 catalyzed by Pd (0) to furnish the corresponding (E)-α,β-unsaturated trifluoromethyl ketones 5 in good yields.
The halogenation of (Z)-β-Trifluoroacetylvinyltelluride 1 leads to the unexpected pure (E)-β-trifluoroacetylvinyl halides 3,which are allowed to react with organozinc reagents 4 catalyzed by Pd (0) to furnish the corresponding (E)-α,β-unsaturated trifluoromethyl ketones 5 in good yields.
1996, 7(4): 303-304
Abstract:
A new farnesane-based sesquiterpene lactone,3-[(5-hydroxy)homogeranyl]-△2-butenolide,was synthesized for the first time starting from trans,trans-farnesol through five steps in an overall yield of 6.4% as its racemic form.
A new farnesane-based sesquiterpene lactone,3-[(5-hydroxy)homogeranyl]-△2-butenolide,was synthesized for the first time starting from trans,trans-farnesol through five steps in an overall yield of 6.4% as its racemic form.
1996, 7(4): 305-308
Abstract:
Michael addition and an unexpected tandem addition-rearrangement reaction occurred when p-nitrophenylsulfonylacetonitrile (1) reacted with α,β-unsaturated esters and nitriles (2a-f).Different products can be obtained depending on the particular reaction conditions chosen.All new produets (3 and 4,6) were characterized by spectroscopy.
Michael addition and an unexpected tandem addition-rearrangement reaction occurred when p-nitrophenylsulfonylacetonitrile (1) reacted with α,β-unsaturated esters and nitriles (2a-f).Different products can be obtained depending on the particular reaction conditions chosen.All new produets (3 and 4,6) were characterized by spectroscopy.
1996, 7(4): 309-312
Abstract:
2-Amino-5-thio-1,3,4-thiadiazoline and 1-O-acetyl-2,3,5-tri-O-benzoylribofuranose were allowed to react by fusion or by the Vorbrüggen procedure.Two products were isolated and characterized to be positional isomers 4-(β-D-ribofuranosyl)-2-amino-5-thio-1,3,4-thiadiazoline and 3-(β-D-ribofuranosyl)-2-imino-5-thio-1,2,4-thiadiazoline by 1H,13C NMR,mass spectra as well as crystallographic analysis.
2-Amino-5-thio-1,3,4-thiadiazoline and 1-O-acetyl-2,3,5-tri-O-benzoylribofuranose were allowed to react by fusion or by the Vorbrüggen procedure.Two products were isolated and characterized to be positional isomers 4-(β-D-ribofuranosyl)-2-amino-5-thio-1,3,4-thiadiazoline and 3-(β-D-ribofuranosyl)-2-imino-5-thio-1,2,4-thiadiazoline by 1H,13C NMR,mass spectra as well as crystallographic analysis.
1996, 7(4): 313-316
Abstract:
Some new polyimides containing bithiazole rings were prepared by reacting 2,2'-diamino-4,4'-bisthiazole with different aromatic dianhydrides.The polyimides obtained had inherent viscosities of 0.37-0.82 dL/g.Thermogravimetric analysis of the polyimides showed good thermal stability,the temperature at 5% weight loss being from 450℃ to 560℃.The permeability of two polymer membranes to H2,O2 and N2 was determined.
Some new polyimides containing bithiazole rings were prepared by reacting 2,2'-diamino-4,4'-bisthiazole with different aromatic dianhydrides.The polyimides obtained had inherent viscosities of 0.37-0.82 dL/g.Thermogravimetric analysis of the polyimides showed good thermal stability,the temperature at 5% weight loss being from 450℃ to 560℃.The permeability of two polymer membranes to H2,O2 and N2 was determined.
1996, 7(4): 317-318
Abstract:
A facile total synthesis of 6-pentyl-α-pyrone 1 has been described.The key step is the treatment of 2-furyl-pentyl-carbinol 3 with NBS in aqueous tetrahydrofuran (THF).The overall yield is 34%.
A facile total synthesis of 6-pentyl-α-pyrone 1 has been described.The key step is the treatment of 2-furyl-pentyl-carbinol 3 with NBS in aqueous tetrahydrofuran (THF).The overall yield is 34%.
1996, 7(4): 319-320
Abstract:
A simple synthesis of one of natural antitumour styryl lactones,(+)-acetylgoniotriol (1),was achieved utilizing the chiral furylmethanol 3 as a key intermediate.
A simple synthesis of one of natural antitumour styryl lactones,(+)-acetylgoniotriol (1),was achieved utilizing the chiral furylmethanol 3 as a key intermediate.
1996, 7(4): 321-324
Abstract:
A simple,convenient and high-yield preparation for bis-imidazoles,which have a wide range of applications,from imidazole and dibromides in the presence of strong base is reported.
A simple,convenient and high-yield preparation for bis-imidazoles,which have a wide range of applications,from imidazole and dibromides in the presence of strong base is reported.
1996, 7(4): 325-328
Abstract:
A new picket fence porphyrin appended with multiple benzo-15-crown-5 units was synthesized by the reaction of meso-α,α,α,α-tetra (2-aminophenyl) porphyrin and 4'-chlorofortnylbenzo-15-crown-5.Its Fe (Ⅲ) and Zn (Ⅱ) complexes were also prepared and characterized.
A new picket fence porphyrin appended with multiple benzo-15-crown-5 units was synthesized by the reaction of meso-α,α,α,α-tetra (2-aminophenyl) porphyrin and 4'-chlorofortnylbenzo-15-crown-5.Its Fe (Ⅲ) and Zn (Ⅱ) complexes were also prepared and characterized.
1996, 7(4): 329-332
Abstract:
Polymer-bound manganese (Ⅱ) porphyrins are effective catalysts for the epoxidation of olefins by iodosylbenzene.
Polymer-bound manganese (Ⅱ) porphyrins are effective catalysts for the epoxidation of olefins by iodosylbenzene.
1996, 7(4): 333-334
Abstract:
A new neoclerodane type diterpenoid alkaloid,scutebarbatine A,was isolated from the whole plants of Scutellaria bartata D.Don.On the basis of the spectral evidence,its structure was proposed as (1).This type of alkaloid was first discovered in natural products.
A new neoclerodane type diterpenoid alkaloid,scutebarbatine A,was isolated from the whole plants of Scutellaria bartata D.Don.On the basis of the spectral evidence,its structure was proposed as (1).This type of alkaloid was first discovered in natural products.
1996, 7(4): 335-336
Abstract:
A new ellagic acid glycoside named ducheside A has been isolated from Duchesnea indica Focke,and its structure was elucidated as 3'-0-methyl-ellagic acid-4-0-β-D-xylopyranoside on the basis of spectral analysis and hydrolysis.
A new ellagic acid glycoside named ducheside A has been isolated from Duchesnea indica Focke,and its structure was elucidated as 3'-0-methyl-ellagic acid-4-0-β-D-xylopyranoside on the basis of spectral analysis and hydrolysis.
1996, 7(4): 337-340
Abstract:
Oligopeptides related to oxidized glutathione were isolated from aqueous methanol extract of Panax ginseng,through successive column chromatography on ion-exchange,gel-filtration and HPLC.Their structures had been identified with the methods of amino acid component analysis,N-terminal,C-terminal analysis and sequence analysis.
Oligopeptides related to oxidized glutathione were isolated from aqueous methanol extract of Panax ginseng,through successive column chromatography on ion-exchange,gel-filtration and HPLC.Their structures had been identified with the methods of amino acid component analysis,N-terminal,C-terminal analysis and sequence analysis.
1996, 7(4): 341-344
Abstract:
Four new glycosides named ligurobustosides A,B,C and D have been isolated from Ligustrum robustum and their structures identifled as geraniol 3-O-α-L-rhamnopyranosyl-β-D-glucopyranoside (1),geraniol 3-O-α-L-rhamnopyranosyl-4-cafferoyl-β-D-glucopyranoside (2),geraniol 3-O-α-L-rhamnopyranosyl-4-trans-P-coumaroyl-β-D-glucopyranoside (3)and geraniol 3-O-α-L-rhamnopyranosyl-4-cis-P-coumaroyl-β-D-glucopyranoside(4),respectively.
Four new glycosides named ligurobustosides A,B,C and D have been isolated from Ligustrum robustum and their structures identifled as geraniol 3-O-α-L-rhamnopyranosyl-β-D-glucopyranoside (1),geraniol 3-O-α-L-rhamnopyranosyl-4-cafferoyl-β-D-glucopyranoside (2),geraniol 3-O-α-L-rhamnopyranosyl-4-trans-P-coumaroyl-β-D-glucopyranoside (3)and geraniol 3-O-α-L-rhamnopyranosyl-4-cis-P-coumaroyl-β-D-glucopyranoside(4),respectively.
1996, 7(4): 345-346
Abstract:
The metabolism of biphenyldimethyldicarboxylate (BDD),an antihepatitis drug,was studied in human urine by deuterium labeled compound and GC-MS.It was found that the metabolite is mono-O-demethylated BDD,which confirmed the results of previous studies in rats.
The metabolism of biphenyldimethyldicarboxylate (BDD),an antihepatitis drug,was studied in human urine by deuterium labeled compound and GC-MS.It was found that the metabolite is mono-O-demethylated BDD,which confirmed the results of previous studies in rats.
1996, 7(4): 347-350
Abstract:
The retention behaviours of 12 purine and pyrimidine derivatives——thymine,uracil,cytosine,adenine,guanine,xanthine,hypoxanthine,purine,4,6-diaminopyrimidine,theophylline,trimethoprimum and 6-(benzylamino) purine,have been studied by micellar eiectrokinetic capillary chromatography (MECC).10 out of 12 analytes were separated by using 40 mmol/L sodium dodecyl sulfate-10 mmol/L borax-17% methanol-3.0 mmol/L β-cyclddextrin (pH 9.30) as electrolyte.The relative standard deviations (RSD) of tR and UV absorbance were less than 1.8% and 6.5% (n=6),respectively.
The retention behaviours of 12 purine and pyrimidine derivatives——thymine,uracil,cytosine,adenine,guanine,xanthine,hypoxanthine,purine,4,6-diaminopyrimidine,theophylline,trimethoprimum and 6-(benzylamino) purine,have been studied by micellar eiectrokinetic capillary chromatography (MECC).10 out of 12 analytes were separated by using 40 mmol/L sodium dodecyl sulfate-10 mmol/L borax-17% methanol-3.0 mmol/L β-cyclddextrin (pH 9.30) as electrolyte.The relative standard deviations (RSD) of tR and UV absorbance were less than 1.8% and 6.5% (n=6),respectively.
1996, 7(4): 351-352
Abstract:
Measurements of Surface Photovoltage Spectroscopy (SPS) Were carried out for C60 (A) and its anion salt (B) for the first time.With a reference of UV-vis spectra,the results for SPS are discussed in terms of Molecular Orbit (MO) and Surface Photovoltage (SPV) theory.By a comparison between (A) and(B)'s characteristic responses is SPS,a deeper insight into the nature of their photovoltaic properties is obtained.
Measurements of Surface Photovoltage Spectroscopy (SPS) Were carried out for C60 (A) and its anion salt (B) for the first time.With a reference of UV-vis spectra,the results for SPS are discussed in terms of Molecular Orbit (MO) and Surface Photovoltage (SPV) theory.By a comparison between (A) and(B)'s characteristic responses is SPS,a deeper insight into the nature of their photovoltaic properties is obtained.
1996, 7(4): 353-356
Abstract:
A density matrix treatment of the time evolution of the third order polarization response describing the ground state coherence induced by ultrafast pulses is given.The explicit formulas of polarization response for nonresonant and resonant excitation are derived.The results show that the signal can be greatly enhanced in case of resonance.For specification,we discuss the ground-state rotational coherence based on the irreducible tensor algebra.
A density matrix treatment of the time evolution of the third order polarization response describing the ground state coherence induced by ultrafast pulses is given.The explicit formulas of polarization response for nonresonant and resonant excitation are derived.The results show that the signal can be greatly enhanced in case of resonance.For specification,we discuss the ground-state rotational coherence based on the irreducible tensor algebra.
1996, 7(4): 357-360
Abstract:
The association constants (Ka),free energy (△G0),enthalpy (△H0)and entropy (△S0)changes were determined for the inclusion complexation of β-cyclodextrin with a series of 1-substituted naphthalenes in aqueous solution.The △H0-T△S0 plot for the β-cyclodextrin complexes with naphthalene derivatives show a linear relationship with slope of 0.98 and intercept of 14.67.The results were discussed in terms of enthalpy-entropy compensation.
The association constants (Ka),free energy (△G0),enthalpy (△H0)and entropy (△S0)changes were determined for the inclusion complexation of β-cyclodextrin with a series of 1-substituted naphthalenes in aqueous solution.The △H0-T△S0 plot for the β-cyclodextrin complexes with naphthalene derivatives show a linear relationship with slope of 0.98 and intercept of 14.67.The results were discussed in terms of enthalpy-entropy compensation.
1996, 7(4): 361-364
Abstract:
In this work,we used a linear CCD to detect the whole physical developing process of silver diffusion transfer reversal process in photographic chemistry.The influence of the ingredient of the working solution was studied.
In this work,we used a linear CCD to detect the whole physical developing process of silver diffusion transfer reversal process in photographic chemistry.The influence of the ingredient of the working solution was studied.
1996, 7(4): 365-366
Abstract:
Fast simulated annealing is implemented into the learning process of neural network to replace the traditional back-propagation algorithm.The new procedure exhibits performance fast in learning and accurate in prediction compared to the traditional neural networks:Two numerical data sets were used to illustrate its use in chemistry.
Fast simulated annealing is implemented into the learning process of neural network to replace the traditional back-propagation algorithm.The new procedure exhibits performance fast in learning and accurate in prediction compared to the traditional neural networks:Two numerical data sets were used to illustrate its use in chemistry.
1996, 7(4): 367-370
Abstract:
The block copolymers were synthesized by anionic polymerization via two steps reaction.First,styrene was initiated by n-butyl lithium,then maleimides were added into the living styrene system to obtain block copolymers.1H-NMR and FT-IR measurements indicated that block copolymers had been formed.From the results of thermogravimetric analysis,it could be concluded that the block copolymer had a much better thermal stability than random copolymers prepared by radical polymerization.Also the surface hydrophilicities of the two kinds of copolymers were compared.
The block copolymers were synthesized by anionic polymerization via two steps reaction.First,styrene was initiated by n-butyl lithium,then maleimides were added into the living styrene system to obtain block copolymers.1H-NMR and FT-IR measurements indicated that block copolymers had been formed.From the results of thermogravimetric analysis,it could be concluded that the block copolymer had a much better thermal stability than random copolymers prepared by radical polymerization.Also the surface hydrophilicities of the two kinds of copolymers were compared.
1996, 7(4): 371-374
Abstract:
The aggregation behavior of a side chain liquid crystalline polymer (PSLC) has been investigated by means of surface pressure-area isotherm,TEM and SEM observation,X-ray diffraction,and UV-vis spectroscopy.Results obtained can be explained by molecular exciton model.
The aggregation behavior of a side chain liquid crystalline polymer (PSLC) has been investigated by means of surface pressure-area isotherm,TEM and SEM observation,X-ray diffraction,and UV-vis spectroscopy.Results obtained can be explained by molecular exciton model.
1996, 7(4): 375-376
Abstract:
A method of preparing stable,film-forming polyurethane latices without the use of emulsifying agents is described in this article.The reaction of polypropylene glycol with a stoichiometric ratio (NCO:OH=2:1) of tolylene-diisocyanate in the presence of ketones and catalyst produces an isocyanate terminated prepolymer.Then addition of diethylene glycol as chain extender to prepolymer solution can yield a relatively high molecular weight poly (urethane-ether) which is readily dispersed with aqueous tartaric acid after tartaric acid and water diffuse into the suspended globules of the latex and produces the chain extended urethane.A linear or crosslinked high molecular weight self-emulsifiable polyurcthane can be obtained due to the reaction of the hydroxy group of tartaric acid and little water with isocyanate endgroups.The results of FTIR also show that an expected polyurethane emulsion has been successfully synthesized.
A method of preparing stable,film-forming polyurethane latices without the use of emulsifying agents is described in this article.The reaction of polypropylene glycol with a stoichiometric ratio (NCO:OH=2:1) of tolylene-diisocyanate in the presence of ketones and catalyst produces an isocyanate terminated prepolymer.Then addition of diethylene glycol as chain extender to prepolymer solution can yield a relatively high molecular weight poly (urethane-ether) which is readily dispersed with aqueous tartaric acid after tartaric acid and water diffuse into the suspended globules of the latex and produces the chain extended urethane.A linear or crosslinked high molecular weight self-emulsifiable polyurcthane can be obtained due to the reaction of the hydroxy group of tartaric acid and little water with isocyanate endgroups.The results of FTIR also show that an expected polyurethane emulsion has been successfully synthesized.
1996, 7(4): 377-380
Abstract:
The surface active water-soluble phosphine,P[p-C6H4O(CH2CH2O)nH]3,n=4,is used to generate an aqueous rhodium catalyst for the hydroformylation of dodecene-1.Under 100℃,5.0 MPa (CO/H2=1:1),pH=6.5,and reaction time 4h,the conversion of dodecene-1 was 96.0%,the yield for aldehyde was 84.0%,and n/i=1.8.The catalyst can be reused for more than four times without any appreciable loss in activity and selectivity.
The surface active water-soluble phosphine,P[p-C6H4O(CH2CH2O)nH]3,n=4,is used to generate an aqueous rhodium catalyst for the hydroformylation of dodecene-1.Under 100℃,5.0 MPa (CO/H2=1:1),pH=6.5,and reaction time 4h,the conversion of dodecene-1 was 96.0%,the yield for aldehyde was 84.0%,and n/i=1.8.The catalyst can be reused for more than four times without any appreciable loss in activity and selectivity.
1996, 7(4): 381-384
Abstract:
The reactions of clusters (μ3-CCO2Et) Co2M (CO)5 (MeCp) [M=Mo (2a),W (2b)],derived from the reaction of (μ3-CCO2Et) Co3 (CO)9 with Na [M (CO)3 (MeCp)],with Na2 [Fe (CO)4] in THF at reflux not only gave the expected metal fragment exchange products (μ3-CCO2Et) FeCoM (CO)6 (Me-Cp) H [M=Mo (3a),W (3b)] but also produced the unexpected compounds (μ3-CCO) FeCoM (CO)5 (MeCp) [M=Mo (4a),W (4b)].It is suggested that the formation of two kinds of compounds resulted from two competitive reactions of the intermediates [(μ3-CCO2Et)FeCoM (CO)5(MeCp)] with H+:the one is the protonic reaction of the intermediate giving the cluster 3a,b;the another one is the intermolecular nucleophilic substitution reaction of the intermediate under the H+ catalytic action giving the cluster 4a,b.
The reactions of clusters (μ3-CCO2Et) Co2M (CO)5 (MeCp) [M=Mo (2a),W (2b)],derived from the reaction of (μ3-CCO2Et) Co3 (CO)9 with Na [M (CO)3 (MeCp)],with Na2 [Fe (CO)4] in THF at reflux not only gave the expected metal fragment exchange products (μ3-CCO2Et) FeCoM (CO)6 (Me-Cp) H [M=Mo (3a),W (3b)] but also produced the unexpected compounds (μ3-CCO) FeCoM (CO)5 (MeCp) [M=Mo (4a),W (4b)].It is suggested that the formation of two kinds of compounds resulted from two competitive reactions of the intermediates [(μ3-CCO2Et)FeCoM (CO)5(MeCp)] with H+:the one is the protonic reaction of the intermediate giving the cluster 3a,b;the another one is the intermolecular nucleophilic substitution reaction of the intermediate under the H+ catalytic action giving the cluster 4a,b.
1996, 7(4): 385-386
Abstract:
(Me2GeGeMe2) [(η5-C5H4)Fe(CO)]2 (μ-CO)2,1 undergoes a novel reaction between its Ge-Ge and Fe-Fe bonds,forming a rearrangement product with a new cyclic structure,(Me2Ge(η5-C5H4)Fe(CO)2]2,2,which was determined by single crystal X-ray diffraction.
(Me2GeGeMe2) [(η5-C5H4)Fe(CO)]2 (μ-CO)2,1 undergoes a novel reaction between its Ge-Ge and Fe-Fe bonds,forming a rearrangement product with a new cyclic structure,(Me2Ge(η5-C5H4)Fe(CO)2]2,2,which was determined by single crystal X-ray diffraction.
1996, 7(4): 387-388
Abstract:
In this paper we have synthesized powder crystal form (Y,Gd) BO3:Eu3+phosphors by microwave heating method.Its structure belongs to hexagonal system with lattice parameters a=0.3796,c=0.8835.Its excitation spectra peaks at 239.0nm and 240.0nm monitored at the emission of 589nm and 612nm respectively,the half peak width is 40nm.Under 240nm excitation the phosphors show a strong orange-red luminescence,the fluorescent intensity ratio for I589/I612 is 1.9/1
In this paper we have synthesized powder crystal form (Y,Gd) BO3:Eu3+phosphors by microwave heating method.Its structure belongs to hexagonal system with lattice parameters a=0.3796,c=0.8835.Its excitation spectra peaks at 239.0nm and 240.0nm monitored at the emission of 589nm and 612nm respectively,the half peak width is 40nm.Under 240nm excitation the phosphors show a strong orange-red luminescence,the fluorescent intensity ratio for I589/I612 is 1.9/1
1996, 7(4): 389-390
Abstract:
The preliminary work indicated that passive film is the most important factor influencing cell performance of carbon anode,and the carbon and solvent used govern cell performance by forming the passive film of different properties.A in situ XRD result is also presented.
The preliminary work indicated that passive film is the most important factor influencing cell performance of carbon anode,and the carbon and solvent used govern cell performance by forming the passive film of different properties.A in situ XRD result is also presented.
1996, 7(4): 391-392
Abstract:
Chemical solution deposited CdSe particulate films possess nanocrvstalline structure and exhibit quantum size effects.By changing the temperature of chemical deposition and subsequent annealing,CdSe particulate films with different particle sizes can be obtained.
Chemical solution deposited CdSe particulate films possess nanocrvstalline structure and exhibit quantum size effects.By changing the temperature of chemical deposition and subsequent annealing,CdSe particulate films with different particle sizes can be obtained.
