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2000 Volume 11 Issue 2
2000, 12(2): 95-96
Abstract:
A new, mild and efficient method for the cleavage of 1,3-dioxolane is reported.
A new, mild and efficient method for the cleavage of 1,3-dioxolane is reported.
2000, 12(2): 97-98
Abstract:
The photostimulated reactions of benzyl chloride with carbazolyl nitrogen anion in dimethyl sulfoxide gave 9-benzylcarbazole and 3-benzylcarbazole.The reactions are suggested in term of SRN1 mechanism of nucleophilic substitution.
The photostimulated reactions of benzyl chloride with carbazolyl nitrogen anion in dimethyl sulfoxide gave 9-benzylcarbazole and 3-benzylcarbazole.The reactions are suggested in term of SRN1 mechanism of nucleophilic substitution.
2000, 12(2): 99-100
Abstract:
Symmetric diesters of cis-or trans-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylate were prepared by aqueous Diels-Alder reaction of cyclopentadiene with symmetric diester of fumarate or maleate.
Symmetric diesters of cis-or trans-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylate were prepared by aqueous Diels-Alder reaction of cyclopentadiene with symmetric diester of fumarate or maleate.
2000, 12(2): 101-102
Abstract:
gem-Dichlorocyclopropanes were effectively reduced by lithium aluminum hydride, and monocylopropanes were obtained in good yields.
gem-Dichlorocyclopropanes were effectively reduced by lithium aluminum hydride, and monocylopropanes were obtained in good yields.
2000, 12(2): 103-104
Abstract:
The synthesis of a novel polyorganophosphazene that contains charge-transporting agent as side chains for photoconductive application is reported.Structural characterization for the high polymer was presented by 1H-NMR, infrared spectrosocopy, gel permeation chromatography (GPC) .
The synthesis of a novel polyorganophosphazene that contains charge-transporting agent as side chains for photoconductive application is reported.Structural characterization for the high polymer was presented by 1H-NMR, infrared spectrosocopy, gel permeation chromatography (GPC) .
2000, 12(2): 105-106
Abstract:
A novel model for the 1:2 complex of piperazine with some phenols in solution is established and verified.In CDCl3 solution, one piperazine molecule is tied to two phenol molecules by hydrogen bonds of O-H---N and N-H---O.And the protons of > NH and-OH groups exchange quickly and simultaneously between the atoms of phenol oxygen and piperazine nitrogen.
A novel model for the 1:2 complex of piperazine with some phenols in solution is established and verified.In CDCl3 solution, one piperazine molecule is tied to two phenol molecules by hydrogen bonds of O-H---N and N-H---O.And the protons of > NH and-OH groups exchange quickly and simultaneously between the atoms of phenol oxygen and piperazine nitrogen.
2000, 12(2): 107-108
Abstract:
Convenient, efficient one-pot synthesis of ferrocenylcyanide, which is a very important intermediate in synthesis of chiral ferrocenyl ligands in asymmetric catalysis, is described.The chemical yield is up to 60%.
Convenient, efficient one-pot synthesis of ferrocenylcyanide, which is a very important intermediate in synthesis of chiral ferrocenyl ligands in asymmetric catalysis, is described.The chemical yield is up to 60%.
2000, 12(2): 109-110
Abstract:
A pair of Z and E isomers of cyclization of γ-ketoacid 7,which was prepared in six steps from 2,5-dimethoxyphenyl acetic acid 1, gave a pair of Z(20%) and E (4%) isomers of (2,5-dimethoxyphenyl)-methylene-butyrolactones
A pair of Z and E isomers of cyclization of γ-ketoacid 7,which was prepared in six steps from 2,5-dimethoxyphenyl acetic acid 1, gave a pair of Z(20%) and E (4%) isomers of (2,5-dimethoxyphenyl)-methylene-butyrolactones
2000, 12(2): 111-112
Abstract:
The C-11 isomer of natural trihydroxyl sesquiterpene 5-epi-kudtriol has been synthesized starting from (+)-dihydrocarvone via asymmetric dihydroxylation as a key step.
The C-11 isomer of natural trihydroxyl sesquiterpene 5-epi-kudtriol has been synthesized starting from (+)-dihydrocarvone via asymmetric dihydroxylation as a key step.
2000, 12(2): 115-118
Abstract:
Two novel heteroatom–bridged bis (benzo-12-crown-4 ether)s, i.e.bis [2-nitro-4,5-(1,4,7,10-tetraoxadecamethylene)phenyl] disulfide 1 and diselenide 2, have been synthesized.X-ray crystallographic structure was obtained for 1.Ion selective electrodes (ISE) for Ag+, containing 1 and 2 in PVC membrane as neutral carriers, were prepared, and their selectivity coefficients for Ag+ (kag.alpot) were determined against other heavy metal ions, alkali and alkaline-earth metal ions, and ammonium ion.These ISEs showed excellent Ag+ selectivities, logkag.alpot≤-3.8, against most of the interfering cations examined, except for Hg+.
Two novel heteroatom–bridged bis (benzo-12-crown-4 ether)s, i.e.bis [2-nitro-4,5-(1,4,7,10-tetraoxadecamethylene)phenyl] disulfide 1 and diselenide 2, have been synthesized.X-ray crystallographic structure was obtained for 1.Ion selective electrodes (ISE) for Ag+, containing 1 and 2 in PVC membrane as neutral carriers, were prepared, and their selectivity coefficients for Ag+ (kag.alpot) were determined against other heavy metal ions, alkali and alkaline-earth metal ions, and ammonium ion.These ISEs showed excellent Ag+ selectivities, logkag.alpot≤-3.8, against most of the interfering cations examined, except for Hg+.
2000, 12(2): 119-122
Abstract:
In this paper, the abstraction reaction of CH3SiH3 with H has been studied by using the "direct dynamics" method of variational transition-state theory, which is based on the information on geometries, frequencies and energies calculated by ab initio along the minimum energy path.The rate constants of the title reaction were calculated for the range of temperature 298-1700 K.The rate constants calculated match well with the experimental values.
In this paper, the abstraction reaction of CH3SiH3 with H has been studied by using the "direct dynamics" method of variational transition-state theory, which is based on the information on geometries, frequencies and energies calculated by ab initio along the minimum energy path.The rate constants of the title reaction were calculated for the range of temperature 298-1700 K.The rate constants calculated match well with the experimental values.
2000, 12(2): 123-126
Abstract:
The characters of coupling between two doublet NO radicals linked through electron-rich rings have been studied.The results demonstrate that the molecules have triplet ground states, and ferromagnetic coupling exists in these molecules.
The characters of coupling between two doublet NO radicals linked through electron-rich rings have been studied.The results demonstrate that the molecules have triplet ground states, and ferromagnetic coupling exists in these molecules.
2000, 12(2): 127-128
Abstract:
Two new indole alkaloids, wuchuyuamide I and II were isolated from the fruits of Evodia rutaecarpa (Juss.) Benth and their structures were elucidated on the basis of spectral data.
Two new indole alkaloids, wuchuyuamide I and II were isolated from the fruits of Evodia rutaecarpa (Juss.) Benth and their structures were elucidated on the basis of spectral data.
2000, 12(2): 129-130
Abstract:
A new alkaloid, named prolifine (1), was isolated along with four known alkaloids, liriodenine (2), 6-hydroxyonychine (3), isooncodine (4) and discretamine (5) from the roots of Saccopetalum prolificum.The structure of 1 was elucidated on the basis of spectroscopic and chemical methods.
A new alkaloid, named prolifine (1), was isolated along with four known alkaloids, liriodenine (2), 6-hydroxyonychine (3), isooncodine (4) and discretamine (5) from the roots of Saccopetalum prolificum.The structure of 1 was elucidated on the basis of spectroscopic and chemical methods.
2000, 12(2): 131-132
Abstract:
A new flavone glycoside, named mahuangchiside, was isolated from the root of Chirita fimbrisepala Hand.-Mazz.The structure was elucidated as 5,4’-dihydroxy-6-methoxy-flavone-7-O-β-D-xylopyranosyl(1→2)-β-D-xylopyranoside on the basis of spectral analysis (1H-1H COSY, 13C-1H HETCOR and HMBC) and chemical evidence.
A new flavone glycoside, named mahuangchiside, was isolated from the root of Chirita fimbrisepala Hand.-Mazz.The structure was elucidated as 5,4’-dihydroxy-6-methoxy-flavone-7-O-β-D-xylopyranosyl(1→2)-β-D-xylopyranoside on the basis of spectral analysis (1H-1H COSY, 13C-1H HETCOR and HMBC) and chemical evidence.
2000, 12(2): 133-134
Abstract:
A new bislabdane-type diterpenoid lanceolactin (1), was isolated from the roots of Cunninghamia lanceolata.Its structure was elucidated on the basis of spectroscopic methods, especially 2D-NMR techniques.
A new bislabdane-type diterpenoid lanceolactin (1), was isolated from the roots of Cunninghamia lanceolata.Its structure was elucidated on the basis of spectroscopic methods, especially 2D-NMR techniques.
2000, 12(2): 135-138
Abstract:
A new bianthraquinone glycoside, 8-O-β-D-glucopyranosyl-2,7'-bi(1,8-dihydroxy-3-methyl-9,10-anthraquinonyl) 1 was isolated from Eremurus chinensis Fedtch.Its structure was established by spectroscopic techniques including 2D-NMR and chemical methods.
A new bianthraquinone glycoside, 8-O-β-D-glucopyranosyl-2,7'-bi(1,8-dihydroxy-3-methyl-9,10-anthraquinonyl) 1 was isolated from Eremurus chinensis Fedtch.Its structure was established by spectroscopic techniques including 2D-NMR and chemical methods.
2000, 12(2): 139-142
Abstract:
Two new triterpenoid saponins, named isoescins IIIa (1) and IIIb (2) were isolated from the seeds of Aesculus chinensis and identified by spectroscopic analysis and chemical hydrolysis.Their structures were established as 21b-tigloyl-28-acetylbarringtogenol C-3β-O-[b-D-galactopyranosyl (1→2)] [β-D-glucopyranosyl (1→4)]-β-D-glucopyranosiduronic acid (1) and 21β-angeloyl-28-acetylbarringtogenol C-3β-O-[β-D-galactopyranosyl (1→2)] [b-D-glucopyrano-syl (1→4)]-β-D-glucopyranosiduronic acid (2), which are geometrically isomeric.
Two new triterpenoid saponins, named isoescins IIIa (1) and IIIb (2) were isolated from the seeds of Aesculus chinensis and identified by spectroscopic analysis and chemical hydrolysis.Their structures were established as 21b-tigloyl-28-acetylbarringtogenol C-3β-O-[b-D-galactopyranosyl (1→2)] [β-D-glucopyranosyl (1→4)]-β-D-glucopyranosiduronic acid (1) and 21β-angeloyl-28-acetylbarringtogenol C-3β-O-[β-D-galactopyranosyl (1→2)] [b-D-glucopyrano-syl (1→4)]-β-D-glucopyranosiduronic acid (2), which are geometrically isomeric.
2000, 12(2): 143-146
Abstract:
Two new triterpenoid saponin dimers, named rubupungenoside A (1) and B (2), have been isolated from the aerial parts of Rubus pungens Camb.var.oldhamii.Their structures have been established on the basis of spectroscopic methods and chemical transformations.
Two new triterpenoid saponin dimers, named rubupungenoside A (1) and B (2), have been isolated from the aerial parts of Rubus pungens Camb.var.oldhamii.Their structures have been established on the basis of spectroscopic methods and chemical transformations.
2000, 12(2): 147-148
Abstract:
The binding behavior of several fluorescence dyes to calf thymus DNA has been studied by absorption, fluorescence and atomic force microscopy (AFM), which could provide direct evidence of formation modes and the corresponding nanostructural features of the ligand-DNA complexes.
The binding behavior of several fluorescence dyes to calf thymus DNA has been studied by absorption, fluorescence and atomic force microscopy (AFM), which could provide direct evidence of formation modes and the corresponding nanostructural features of the ligand-DNA complexes.
2000, 12(2): 149-154
Abstract:
The irreversible conformational transition of bovine serum albumin (BSA) from α-helix to β-sheet, induced by electric field near the electrode surface, was monitored by circular dichroism (CD) with a long optical path thin layer cell (LOPTLC).
The irreversible conformational transition of bovine serum albumin (BSA) from α-helix to β-sheet, induced by electric field near the electrode surface, was monitored by circular dichroism (CD) with a long optical path thin layer cell (LOPTLC).
2000, 12(2): 153-156
Abstract:
β-Cyclodextrin phosphate (β-CD-phosphate) was used as a selector for separating chiral drugs by capillary electrophoresis (CE).A solution comprising of 120 mmol/L Britton-Robinson buffer (BRB) containing 10 mmol/L β-CD phosphate with the pH adjusted to 7.0 was used as the background electrolyte (BGE), and a small amount of analyte was injected (600v/1s).Triethylamine, diethylamine, triethanolamine, diethanolamine, Tris added as modifier were compared.Isoprenaline, methoxamine, oxprenolol, practolol were successfully resolved.
β-Cyclodextrin phosphate (β-CD-phosphate) was used as a selector for separating chiral drugs by capillary electrophoresis (CE).A solution comprising of 120 mmol/L Britton-Robinson buffer (BRB) containing 10 mmol/L β-CD phosphate with the pH adjusted to 7.0 was used as the background electrolyte (BGE), and a small amount of analyte was injected (600v/1s).Triethylamine, diethylamine, triethanolamine, diethanolamine, Tris added as modifier were compared.Isoprenaline, methoxamine, oxprenolol, practolol were successfully resolved.
2000, 12(2): 157-160
Abstract:
A new analytical method for the determination of urea-urease system based on biochemical reaction heat induced laser beam deflection is presented in this paper.With the method, the Michaelis constant (Km) of urease and apparent inhibition constant (Ki) of some metal ion inhibitors were measured respectively.This method was also used for the quantitative determination of metal ions with satisfactory result.
A new analytical method for the determination of urea-urease system based on biochemical reaction heat induced laser beam deflection is presented in this paper.With the method, the Michaelis constant (Km) of urease and apparent inhibition constant (Ki) of some metal ion inhibitors were measured respectively.This method was also used for the quantitative determination of metal ions with satisfactory result.
2000, 12(2): 161-164
Abstract:
Two multilayer films of pyrrolidinofullerene carboxylic acid derivatives, which exhibit photoelectric conversion property, are reported here.The first monolayers were fabricated on hydrophilic indium-tin-oxide (ITO), quartz, and mica by esterification reaction.The multilayers were characterized by contact angle and UV spectrum.The photoelectric conversion properties of both multilayer films were studied.
Two multilayer films of pyrrolidinofullerene carboxylic acid derivatives, which exhibit photoelectric conversion property, are reported here.The first monolayers were fabricated on hydrophilic indium-tin-oxide (ITO), quartz, and mica by esterification reaction.The multilayers were characterized by contact angle and UV spectrum.The photoelectric conversion properties of both multilayer films were studied.
2000, 12(2): 165-166
Abstract:
Nylon membrane was modified by binding with polyhydroxyl-containing materials to increase its hydrophilicity and reduce its nonspecific interaction with proteins.The effect of binding hydrophilic materials on amount of ligand bound--Cibacron Blue F3GA (CBF) was investigated.Experimental data showed that the amount of CBF bound can be increased significantly after binding of hydrophilic materials.
Nylon membrane was modified by binding with polyhydroxyl-containing materials to increase its hydrophilicity and reduce its nonspecific interaction with proteins.The effect of binding hydrophilic materials on amount of ligand bound--Cibacron Blue F3GA (CBF) was investigated.Experimental data showed that the amount of CBF bound can be increased significantly after binding of hydrophilic materials.
2000, 12(2): 167-170
Abstract:
A novel highly active Cs-symmetric metallocene catalyst namely:meso-dimethylsilylbis (2,4,6-trimethyl-1-indenyl)zirconium dichloride is presented.The effect of polymerization temperature (0-70℃) on the catalyst performance for propylene polymerization has been investigated.This catalyst shows very high activity at 50℃ which is higher than the activity of the racemic analogue, and the resulted polypropylene is amorphous in nature with isotactic pentad content [mmmm] of 12 %.
A novel highly active Cs-symmetric metallocene catalyst namely:meso-dimethylsilylbis (2,4,6-trimethyl-1-indenyl)zirconium dichloride is presented.The effect of polymerization temperature (0-70℃) on the catalyst performance for propylene polymerization has been investigated.This catalyst shows very high activity at 50℃ which is higher than the activity of the racemic analogue, and the resulted polypropylene is amorphous in nature with isotactic pentad content [mmmm] of 12 %.
2000, 12(2): 171-174
Abstract:
Layered compound zirconium bis(monohydrogenphosphate)(α-ZrP) intercalated with rare earth complex Eu(DBM)3phen was prepared.The pre-intercalation of p-methoxyaniline into α-ZrP makes the interlayer separation large enough to exchange PMA with europium complex, thus, the luminescent assembly was prepared.This was confirmed by X-ray diffraction, UV-visible spectra and elemental analysis.The fluorescence spectra and lifetime of the assembly were also presented.
Layered compound zirconium bis(monohydrogenphosphate)(α-ZrP) intercalated with rare earth complex Eu(DBM)3phen was prepared.The pre-intercalation of p-methoxyaniline into α-ZrP makes the interlayer separation large enough to exchange PMA with europium complex, thus, the luminescent assembly was prepared.This was confirmed by X-ray diffraction, UV-visible spectra and elemental analysis.The fluorescence spectra and lifetime of the assembly were also presented.
2000, 12(2): 175-178
Abstract:
Partial oxidation of methane and ethane to syngas over a LiLaNiO/γ-Al2H3 catalyst was investigated with a flow-reactor, XPS and XRD.Excellent reaction performance for CH4-C2H6-O2 to syngas over the LiLaNiO/γ-Al2H3 catalyst was achieved at 1073K, obtaining CO selectivity of 90%-95% and CH4 conversion of~97%, with a wide range of C2H6 content in the feed and of space velocity.
Partial oxidation of methane and ethane to syngas over a LiLaNiO/γ-Al2H3 catalyst was investigated with a flow-reactor, XPS and XRD.Excellent reaction performance for CH4-C2H6-O2 to syngas over the LiLaNiO/γ-Al2H3 catalyst was achieved at 1073K, obtaining CO selectivity of 90%-95% and CH4 conversion of~97%, with a wide range of C2H6 content in the feed and of space velocity.
2000, 12(2): 179-180
Abstract:
A zirconia-pillared layered lanthanum niobate was prepared by first preswelling layered HLaNb2O7 with n-hexadecylamine(n-C16H33NH2), then further reacting with zirconyl chloride aqueous solution, and finally calcining the resultant solid product in air.The obtained new material has an interlayer spacing of 1.36nm, and a high thermal stability above 700℃.
A zirconia-pillared layered lanthanum niobate was prepared by first preswelling layered HLaNb2O7 with n-hexadecylamine(n-C16H33NH2), then further reacting with zirconyl chloride aqueous solution, and finally calcining the resultant solid product in air.The obtained new material has an interlayer spacing of 1.36nm, and a high thermal stability above 700℃.
2000, 12(2): 181-184
Abstract:
The cobalt precursor affects the catalytic performance of Co/SiO2 catalyst remarkably.The catalyst prepared from cobalt acetate exhibits excellent activity, stability and resistance to carbon deposition.
The cobalt precursor affects the catalytic performance of Co/SiO2 catalyst remarkably.The catalyst prepared from cobalt acetate exhibits excellent activity, stability and resistance to carbon deposition.
2000, 12(2): 185-188
Abstract:
A new phase of Gd2-xNaxCuO4 was synthesized by direct precipitation from the mixture of Gd2O3 and CuO in the molten KOH/NaOH/KNO3 solution at temperature as low as 280℃.The resulting precipitate was characterized by using SEM, XRD, EDX, XPS and magnetic method.The XRD data indicate that the precipitated Gd2-xNaxCuO4 is monoclinic with lattice parameters a=8.6816Å, b=3.7233Å.c=6.0796Å, α=γ=90°, β=108.75° and v=186.1Å3.
A new phase of Gd2-xNaxCuO4 was synthesized by direct precipitation from the mixture of Gd2O3 and CuO in the molten KOH/NaOH/KNO3 solution at temperature as low as 280℃.The resulting precipitate was characterized by using SEM, XRD, EDX, XPS and magnetic method.The XRD data indicate that the precipitated Gd2-xNaxCuO4 is monoclinic with lattice parameters a=8.6816Å, b=3.7233Å.c=6.0796Å, α=γ=90°, β=108.75° and v=186.1Å3.
