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1994 Volume 5 Issue 9
1994, 5(9): 737-740
Abstract:
The Mannich reaction of HGeCl3 has been studied for the first time,giving good yields.However,the products are relatively unstable,gradually decomposing into (GeCl2)n,corresponding aldehyde and amine salt,On the contrary,its sesquioxide is very stable and was smoothly obtained.
The Mannich reaction of HGeCl3 has been studied for the first time,giving good yields.However,the products are relatively unstable,gradually decomposing into (GeCl2)n,corresponding aldehyde and amine salt,On the contrary,its sesquioxide is very stable and was smoothly obtained.
1994, 5(9): 741-742
Abstract:
Ammonium chlorochromate (NH4CrO3Cl,ACC) was used to oxidize benzyl athers to the corresponding benzoates under dry conditions as well as in the mixed solvent of DMF and HOAc.
Ammonium chlorochromate (NH4CrO3Cl,ACC) was used to oxidize benzyl athers to the corresponding benzoates under dry conditions as well as in the mixed solvent of DMF and HOAc.
1994, 5(9): 743-746
Abstract:
Two new maytansinoid compounds, mallotusine and isomallotusine from Mallotus anomalus showed strong antitumor activity in vitro and in vivo test. Their structures were established by intensive 2D NMR techniques and MS spectral analyses as well as comparison with that of maytansine.
Two new maytansinoid compounds, mallotusine and isomallotusine from Mallotus anomalus showed strong antitumor activity in vitro and in vivo test. Their structures were established by intensive 2D NMR techniques and MS spectral analyses as well as comparison with that of maytansine.
1994, 5(9): 747-750
Abstract:
Three new bioactive mono-tctrahydrofuranic γ-lactone acetogenins,named muricatin A(1),b(2),C(4) respectively and a known compound gigantetrocin (3),were isolated from Annona muricata Linn.Their structure elucidation was achieved by spectroscopic means.
Three new bioactive mono-tctrahydrofuranic γ-lactone acetogenins,named muricatin A(1),b(2),C(4) respectively and a known compound gigantetrocin (3),were isolated from Annona muricata Linn.Their structure elucidation was achieved by spectroscopic means.
1994, 5(9): 751-754
Abstract:
A new cyclopeptide named arenarin A(1) was obtained from the roots of Arenaria juncea Bieb and its structure was established to be cyclo(Ser-Ser-Phe-lle-Pro-Pro-Phe) by a combination of 2D-NMR and FABMS.
A new cyclopeptide named arenarin A(1) was obtained from the roots of Arenaria juncea Bieb and its structure was established to be cyclo(Ser-Ser-Phe-lle-Pro-Pro-Phe) by a combination of 2D-NMR and FABMS.
1994, 5(9): 755-756
Abstract:
An investigation of the alkaloids of Delphinium swinanense var.leptopogon resulted in the isolation and identification of two new C19-diterpene alkaloids named swinanine A and B,together with one known tatsiensine.The structures of the new alkaloids were established from spectral evidence.
An investigation of the alkaloids of Delphinium swinanense var.leptopogon resulted in the isolation and identification of two new C19-diterpene alkaloids named swinanine A and B,together with one known tatsiensine.The structures of the new alkaloids were established from spectral evidence.
1994, 5(9): 757-760
Abstract:
Two new diterpene glycosides,inulosides A and B,have been isolated from Inula britannica L. var chinensis and their structures established as (-)-17-O-β-D-glucopyranosyl-16α-kauran-19-oic acid and (-)-17-O-β-D-glucopyran-osyl-16α-kauran-19-oic acid-19-O-β-D-glucopyranoside,respectively,through spectral data,and chemical and enzymatical methods.
Two new diterpene glycosides,inulosides A and B,have been isolated from Inula britannica L. var chinensis and their structures established as (-)-17-O-β-D-glucopyranosyl-16α-kauran-19-oic acid and (-)-17-O-β-D-glucopyran-osyl-16α-kauran-19-oic acid-19-O-β-D-glucopyranoside,respectively,through spectral data,and chemical and enzymatical methods.
1994, 5(9): 761-764
Abstract:
A new oleanane-type triterpene saponin,asteryunnanoside E,has been isolated from the roots of Aster yunnanensis Franch,and its structure elucidated as 3-O-β-D-glucopyranosyl-bayogenin-28-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside by means of spectral data particularly 2D NMR including COSY,HETCOR,HOHAHA and ROESY techniques and chemical transformation.
A new oleanane-type triterpene saponin,asteryunnanoside E,has been isolated from the roots of Aster yunnanensis Franch,and its structure elucidated as 3-O-β-D-glucopyranosyl-bayogenin-28-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside by means of spectral data particularly 2D NMR including COSY,HETCOR,HOHAHA and ROESY techniques and chemical transformation.
1994, 5(9): 765-766
Abstract:
The possibilities of capillary zone electrophoresis (CZE) and micellar electrokinetie capillary chromatography (MECC) were investigated for the qualitative analysis of ten protected amino acids and peptides,The results show that MECC method has a better separation than CZE for these compounds.
The possibilities of capillary zone electrophoresis (CZE) and micellar electrokinetie capillary chromatography (MECC) were investigated for the qualitative analysis of ten protected amino acids and peptides,The results show that MECC method has a better separation than CZE for these compounds.
1994, 5(9): 767-768
Abstract:
In this letter,we first reported a novel method——indirect thermo-optical detection used in CE separation of native amino acids.By using methylene blue as background absorber,the detection limit for lysine was 5×10-6 mol/L.
In this letter,we first reported a novel method——indirect thermo-optical detection used in CE separation of native amino acids.By using methylene blue as background absorber,the detection limit for lysine was 5×10-6 mol/L.
1994, 5(9): 769-772
Abstract:
The successive six step reductions of C70 in watar-free acetonitrile-xylene (1:4) mixed solvent containing 0.1 mol/L tetrabutylammonium hexafluorophosphate (Bu4NPF4) were obtained at below 20℃ by using Au and Pt microdisk electrodes.Several electrochemical data were determined.
The successive six step reductions of C70 in watar-free acetonitrile-xylene (1:4) mixed solvent containing 0.1 mol/L tetrabutylammonium hexafluorophosphate (Bu4NPF4) were obtained at below 20℃ by using Au and Pt microdisk electrodes.Several electrochemical data were determined.
1994, 5(9): 773-776
Abstract:
Glucose oxidase (GOD) and cellulase were immobilized on the hydrogen-bond complex of chitosan and sodium carboxymethyl cellulose,The immobilized GOD (IG) can be used in a wider pH range,and its optimum temperature was increased 50℃ higher than its native state;While the optimum temperature of the immobilized cellulase (IC) was increased 20℃ The storage life of IG and IC were prolonged greatly,Both of them can be reused many times,and have a high catalytic activity,Their Michaelis constants Km were determined.
Glucose oxidase (GOD) and cellulase were immobilized on the hydrogen-bond complex of chitosan and sodium carboxymethyl cellulose,The immobilized GOD (IG) can be used in a wider pH range,and its optimum temperature was increased 50℃ higher than its native state;While the optimum temperature of the immobilized cellulase (IC) was increased 20℃ The storage life of IG and IC were prolonged greatly,Both of them can be reused many times,and have a high catalytic activity,Their Michaelis constants Km were determined.
1994, 5(9): 777-778
Abstract:
Alumina coated with potassium fluoride is proved to be a potential solid base catalyst for aldol condensation of indene and acetophenone with aromatic aldehydes,benzofulvenes and chalcones are synthesized in high fields.
Alumina coated with potassium fluoride is proved to be a potential solid base catalyst for aldol condensation of indene and acetophenone with aromatic aldehydes,benzofulvenes and chalcones are synthesized in high fields.
1994, 5(9): 779-780
Abstract:
The complex of palladium with the polymeric meso-tetraphenylporphyrin which is linked by terephthalate has been synthesized.The complex possesses a high catalytic activity for the hydrogenation of 1-hexene and nitrobenzene,and it has been found that the catalytic activity is affected by reaction temperature,concentration of the substrate and the amount of catalyst.
The complex of palladium with the polymeric meso-tetraphenylporphyrin which is linked by terephthalate has been synthesized.The complex possesses a high catalytic activity for the hydrogenation of 1-hexene and nitrobenzene,and it has been found that the catalytic activity is affected by reaction temperature,concentration of the substrate and the amount of catalyst.
1994, 5(9): 781-784
Abstract:
The equilibrium molecular geometry of 25,26,27,28-tetrahydroxycalix[4]arene in cone conformation was calculated by a CNDO/2 method based on the standard geometrical models.The results are in good agreement with those obtained from X-ray analysis.
The equilibrium molecular geometry of 25,26,27,28-tetrahydroxycalix[4]arene in cone conformation was calculated by a CNDO/2 method based on the standard geometrical models.The results are in good agreement with those obtained from X-ray analysis.
1994, 5(9): 785-788
Abstract:
The reaction Cl+CH2I2→ICl+CH2l has been studied at a relative collision energy of 53.2 kJ/mol using the crossed beam technique.Angular and translational energy distributions of reactively scattered ICl products have been measured.The angular distribution is consistent with reaction occurring through a short lived complex with life time about 0.8 of the rotational period.The kinetic energy distributions measured for this system show strong coupling to scattering angles.The forward and backward scattered products have higher translational energy than sideways scattered.A phase space model is developed which can give a good explanation for the experimental energy distributions.
The reaction Cl+CH2I2→ICl+CH2l has been studied at a relative collision energy of 53.2 kJ/mol using the crossed beam technique.Angular and translational energy distributions of reactively scattered ICl products have been measured.The angular distribution is consistent with reaction occurring through a short lived complex with life time about 0.8 of the rotational period.The kinetic energy distributions measured for this system show strong coupling to scattering angles.The forward and backward scattered products have higher translational energy than sideways scattered.A phase space model is developed which can give a good explanation for the experimental energy distributions.
1994, 5(9): 789-790
Abstract:
Photocurrent behaviours of 1,1'-di linolene ferrocenyl LB films modified CdSe thin film electrode were studied by scanned laser spot method.The increase in photocurrent response of modified electrode compared to the bare electrode was analyzed by statistical calculation, The acceleration of interfacial electron transfer by modified molecules which act as redox mediator was discussed.
Photocurrent behaviours of 1,1'-di linolene ferrocenyl LB films modified CdSe thin film electrode were studied by scanned laser spot method.The increase in photocurrent response of modified electrode compared to the bare electrode was analyzed by statistical calculation, The acceleration of interfacial electron transfer by modified molecules which act as redox mediator was discussed.
1994, 5(9): 791-794
Abstract:
Laser-electrochemical doping of poly(N-vinylcarbazole) (PVK) leads to the formation of high conducting PVK polymers.The doped polymers were characterized by IR spectra and electrical conductivity measurement.The results show that the photochemical effects from laser irradiation on the working electrode speed up the reaction rate and increase the doping degree of ClO4- counterion.
Laser-electrochemical doping of poly(N-vinylcarbazole) (PVK) leads to the formation of high conducting PVK polymers.The doped polymers were characterized by IR spectra and electrical conductivity measurement.The results show that the photochemical effects from laser irradiation on the working electrode speed up the reaction rate and increase the doping degree of ClO4- counterion.
1994, 5(9): 795-796
Abstract:
Flexible di(ethyloxy-ether) was introduced into the aromatic copolyesters and copoly(ester-amide)s to reduce the melting point of resulting polymers.The liquid crystallinity was proved by PLM observation and WAXD study.The melting point was greatly reduced,to 200℃ or even lower in some cases,and the molecular weight was satisfactorily high as reflected by inherent viscosity.The copolyester showed better crystallinity and liquid crystallinity than corresponding copoly(ester-amide) with similar monomer composition.
Flexible di(ethyloxy-ether) was introduced into the aromatic copolyesters and copoly(ester-amide)s to reduce the melting point of resulting polymers.The liquid crystallinity was proved by PLM observation and WAXD study.The melting point was greatly reduced,to 200℃ or even lower in some cases,and the molecular weight was satisfactorily high as reflected by inherent viscosity.The copolyester showed better crystallinity and liquid crystallinity than corresponding copoly(ester-amide) with similar monomer composition.
1994, 5(9): 797-798
Abstract:
A new procedure has been developed successfully to prepare the maleimide-terminated poly (arylene ether sulphone) oligomers,It was conducted by the aromatic nucleophilic substitution of the chloro-terminated poly (arylene ether sulphone) oligomer by an endblocking monomer,N-(4-hydroxyphenyl) maleimide.The reaction and structure of the product were confirmed by FT-IR.1H-NMR and elemental analysis.
A new procedure has been developed successfully to prepare the maleimide-terminated poly (arylene ether sulphone) oligomers,It was conducted by the aromatic nucleophilic substitution of the chloro-terminated poly (arylene ether sulphone) oligomer by an endblocking monomer,N-(4-hydroxyphenyl) maleimide.The reaction and structure of the product were confirmed by FT-IR.1H-NMR and elemental analysis.
1994, 5(9): 799-802
Abstract:
Four new binuclear Fe(Ⅱ) complexes containing the dianion of isophthalic acid as bridge have been synthesized,namely[Fe2(IPHTA) (L)4] (ClO4)4 [L denotes 2,2'-bipyridyl(bpy);1,10-phenanthroline (phen);4,4'-dimethyl-2,2'-bipyridyl (Me2bpy) and 5-nitro-1,10-phenanthroline (NO2-phen),respectively],where IPHTA represents the isophthalate dianion.The complex[Fe2(IPHTA)(phen)4](ClO4)4 was characterized with variable temperature magnetic susceptibility (4-300K).The exchange integral J was found to be 9.96 cm-1,indicating that weakly ferromagnetic spin-exchange interaction operates between Fe(Ⅱ) and Fe(Ⅱ) ions.
Four new binuclear Fe(Ⅱ) complexes containing the dianion of isophthalic acid as bridge have been synthesized,namely[Fe2(IPHTA) (L)4] (ClO4)4 [L denotes 2,2'-bipyridyl(bpy);1,10-phenanthroline (phen);4,4'-dimethyl-2,2'-bipyridyl (Me2bpy) and 5-nitro-1,10-phenanthroline (NO2-phen),respectively],where IPHTA represents the isophthalate dianion.The complex[Fe2(IPHTA)(phen)4](ClO4)4 was characterized with variable temperature magnetic susceptibility (4-300K).The exchange integral J was found to be 9.96 cm-1,indicating that weakly ferromagnetic spin-exchange interaction operates between Fe(Ⅱ) and Fe(Ⅱ) ions.
1994, 5(9): 803-806
Abstract:
Two new organic conductor-semiconductor with Cu-containing binuclear polyhalide complex anion (BEDT-TTF)3Cu2Brx(A) and (TTM-TTF) (Cu3Bry) (B) are prepared and the crystal structure of B is determined,The conductivity of the crystal A and B at room temperature along the crystal growth direction is about 10 and 7■10-4 S.cm-1,respectively.
Two new organic conductor-semiconductor with Cu-containing binuclear polyhalide complex anion (BEDT-TTF)3Cu2Brx(A) and (TTM-TTF) (Cu3Bry) (B) are prepared and the crystal structure of B is determined,The conductivity of the crystal A and B at room temperature along the crystal growth direction is about 10 and 7■10-4 S.cm-1,respectively.
1994, 5(9): 807-808
Abstract:
The luminescence properties of K2VOF5 and K3VO2F4 are reported for the first time.The really interesting result obtained is the observation of vibration structure in the emission band of the new compound,K2VOF5,at 4.2K The vibrational mode involved for K2VOF5 is V-O stretching vibration.
The luminescence properties of K2VOF5 and K3VO2F4 are reported for the first time.The really interesting result obtained is the observation of vibration structure in the emission band of the new compound,K2VOF5,at 4.2K The vibrational mode involved for K2VOF5 is V-O stretching vibration.
1994, 5(9): 809-810
Abstract:
The ZnO-Ag core-shell ultrafine particle in ethanol was prepared by photoreduction and colloidal methods.The experimental results obtained from absorption spectroscopy,fluorescence spectroscopy and electron microscopy revealed that the structure of the hybrid particle is ZnO core covered with Ag shell.The thickness of the silver layer can be controlled by the concentration of Ag+ ions and the time of UV irradiation.The structure of the electric double layer of the ZnO seed greatly affects the formation of ZnO-Ag hybrid particle.
The ZnO-Ag core-shell ultrafine particle in ethanol was prepared by photoreduction and colloidal methods.The experimental results obtained from absorption spectroscopy,fluorescence spectroscopy and electron microscopy revealed that the structure of the hybrid particle is ZnO core covered with Ag shell.The thickness of the silver layer can be controlled by the concentration of Ag+ ions and the time of UV irradiation.The structure of the electric double layer of the ZnO seed greatly affects the formation of ZnO-Ag hybrid particle.
1994, 5(9): 811-814
Abstract:
By using microwave technique,cupric chloride was highly dispersed into zeolite Beta with critical dispersion capacity of 0.6 g CuCl2·2H2O/g Beta,From the IR results,it was found that solid state ion-exchange process of copper ions and dispersion process of cupric chloride molecules could simultaneously occur during microwave treatment.High dispersion of cupric chloride molecules results in more active sites for CO adsorption in zeolite Beta.
By using microwave technique,cupric chloride was highly dispersed into zeolite Beta with critical dispersion capacity of 0.6 g CuCl2·2H2O/g Beta,From the IR results,it was found that solid state ion-exchange process of copper ions and dispersion process of cupric chloride molecules could simultaneously occur during microwave treatment.High dispersion of cupric chloride molecules results in more active sites for CO adsorption in zeolite Beta.
