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2000 Volume 11 Issue 9
2000, 11(9): 753-756
Abstract:
t-Butyldimethylsilyl (TBDMS) ether can be cleaved upon refluxing in acetone/H2O (95:5) in the presence of catalytic amount of copper (Ⅱ) chloride dihydrate (5 mmol%).
t-Butyldimethylsilyl (TBDMS) ether can be cleaved upon refluxing in acetone/H2O (95:5) in the presence of catalytic amount of copper (Ⅱ) chloride dihydrate (5 mmol%).
2000, 11(9): 757-760
Abstract:
The reaction of 2-substituted imidazolinium salt with bis-Grignard reagents is reported and a new method for the synthesis of symmetric diketones from carboxylic acids and bis-Grignard reagents is provided.
The reaction of 2-substituted imidazolinium salt with bis-Grignard reagents is reported and a new method for the synthesis of symmetric diketones from carboxylic acids and bis-Grignard reagents is provided.
2000, 11(9): 761-764
Abstract:
Four types of chiral thiazolidine derivatives were synthesized conveniently from natural L-cysteine and showed good enantioselectivity in up to 90% ee in the addition of diethylzinc to benzaldehyde.Their enantioselectivity was affected by the bulkiness of R and the thiazolidine ring systems in their molecules.
Four types of chiral thiazolidine derivatives were synthesized conveniently from natural L-cysteine and showed good enantioselectivity in up to 90% ee in the addition of diethylzinc to benzaldehyde.Their enantioselectivity was affected by the bulkiness of R and the thiazolidine ring systems in their molecules.
2000, 11(9): 765-766
Abstract:
A new 1,3-dichlorodisilazane, 1,3-dichloro-1,3-dimethyl-1,3-divinyldisilazane (DMDV), was prepared from the reaction of hexamethyldisilazane (MMN) and methylvinyldichlorosilane. And use the same method, 1,3-dichloro-1, 1,3, 3-tetraphenyldisilazane (DCTPS) was also obtained in a high yield.
A new 1,3-dichlorodisilazane, 1,3-dichloro-1,3-dimethyl-1,3-divinyldisilazane (DMDV), was prepared from the reaction of hexamethyldisilazane (MMN) and methylvinyldichlorosilane. And use the same method, 1,3-dichloro-1, 1,3, 3-tetraphenyldisilazane (DCTPS) was also obtained in a high yield.
2000, 11(9): 767-770
Abstract:
Reduced rate constants of photoinduced electron transfer in intramolecular fluorescence quenching of donor-acceptor podands induced by cation-complexation are observed in the highly exothermic reactions.
Reduced rate constants of photoinduced electron transfer in intramolecular fluorescence quenching of donor-acceptor podands induced by cation-complexation are observed in the highly exothermic reactions.
2000, 11(9): 771-774
Abstract:
The synthesis of peptoid nucleic acid bearing thymine as nucleobase has been achieved.This modified oligonucleotide showed good hybridization with DNA.
The synthesis of peptoid nucleic acid bearing thymine as nucleobase has been achieved.This modified oligonucleotide showed good hybridization with DNA.
2000, 11(9): 775-776
Abstract:
A new approach to fullerene ferrocenyl derivative has been made.[60]Fullerene reacts with ferrocenylmethyl azide to give N-ferrocenylmethyl imino[60]fullerene in 42% yield.
A new approach to fullerene ferrocenyl derivative has been made.[60]Fullerene reacts with ferrocenylmethyl azide to give N-ferrocenylmethyl imino[60]fullerene in 42% yield.
2000, 11(9): 777-778
Abstract:
A novel poly (aryl ether ketone) (PPEK) containing phthalazinone and naphthalene moieties was prepared by the nucleophilic displacement reaction of 4-(4-hydroxyphenyl) (2H) phthalazin-l-one with 1-chloro-4-(4-chlorobenzoyl) naphthalene.The polymer was characterized by FTIR, 1H-NMR, DSC, TGA and WAXD.
A novel poly (aryl ether ketone) (PPEK) containing phthalazinone and naphthalene moieties was prepared by the nucleophilic displacement reaction of 4-(4-hydroxyphenyl) (2H) phthalazin-l-one with 1-chloro-4-(4-chlorobenzoyl) naphthalene.The polymer was characterized by FTIR, 1H-NMR, DSC, TGA and WAXD.
2000, 11(9): 779-782
Abstract:
Harpagoside, which is one main iridoid constituent of the dried roots of Scrophularia ningpoensis Hemsl., was biotransformated by bacteria isolated from human fecal flora and three metabolites were obtained.The structures of the metabolites, including two new alkaloids, named harpagometabolins I (1) and Ⅱ (2), and a known alkaloid acubinine B (3), were identified by chemical methods and the spectroscopic evidences.
Harpagoside, which is one main iridoid constituent of the dried roots of Scrophularia ningpoensis Hemsl., was biotransformated by bacteria isolated from human fecal flora and three metabolites were obtained.The structures of the metabolites, including two new alkaloids, named harpagometabolins I (1) and Ⅱ (2), and a known alkaloid acubinine B (3), were identified by chemical methods and the spectroscopic evidences.
2000, 11(9): 783-784
Abstract:
A new ceramide, humesamide, was isolated from the soft coral Cladiella humesi Verseveldt, which was collected from Linshui County of Hainan Province.Its structure was established by spectroscopic analysis and chemical degradation methods.
A new ceramide, humesamide, was isolated from the soft coral Cladiella humesi Verseveldt, which was collected from Linshui County of Hainan Province.Its structure was established by spectroscopic analysis and chemical degradation methods.
2000, 11(9): 785-788
Abstract:
Two novel polyoxygenated pyrrolylpyridine and bipyrrole alkaloids, speranskilatine A 1, and speranberculatine A 2, have been isolated from Speranskia tuberculata.Their structures were elucidated by spectroscopic methods including 2D NMR techniques and X-ray crystallographic analysis.
Two novel polyoxygenated pyrrolylpyridine and bipyrrole alkaloids, speranskilatine A 1, and speranberculatine A 2, have been isolated from Speranskia tuberculata.Their structures were elucidated by spectroscopic methods including 2D NMR techniques and X-ray crystallographic analysis.
2000, 11(9): 789-792
Abstract:
Chemical investigation on the neutral fraction of the ethanol extract from the roots of Spiraea japonica var.acuta has resulted in the isolation of one new diterpene amide, spiramide (1). Structure elucidation for 1 was carried out on the basis of 1D and 2D NMR spectra.
Chemical investigation on the neutral fraction of the ethanol extract from the roots of Spiraea japonica var.acuta has resulted in the isolation of one new diterpene amide, spiramide (1). Structure elucidation for 1 was carried out on the basis of 1D and 2D NMR spectra.
2000, 11(9): 793-794
Abstract:
A new enolate derivative of furostanol glycoside, named asparagusin A, was isolated from the roots of Asparagus filicinus and established as 3-O-β-D-xylopyranosyl (1→4)-β-D-glucopyranosyl (25S)-furost-20 (22)-ene-3β, 26-diol 26-O-β-D-glucopyranoside (1) by spectroscopic and chemical methods.Asparagusin A (1) exhibited a cytotoxic activity effect on PC12 cells.
A new enolate derivative of furostanol glycoside, named asparagusin A, was isolated from the roots of Asparagus filicinus and established as 3-O-β-D-xylopyranosyl (1→4)-β-D-glucopyranosyl (25S)-furost-20 (22)-ene-3β, 26-diol 26-O-β-D-glucopyranoside (1) by spectroscopic and chemical methods.Asparagusin A (1) exhibited a cytotoxic activity effect on PC12 cells.
2000, 11(9): 795-798
Abstract:
Two new ent-kaurane diterpenoids, xerophilusin E (1) and xerophilusin F (2), were isolated from the leaves of Isodon xerophilus.Their structures were determined as 3, 20:7, 20 diepoxy-ent-kaur-16-en-15-one and 7β, 14β, 20 (R)-trihydroxy-11β-acetoxy-7, 20-cyclo-ent-kaur-16-en-6, 15-dione, respectively, by spectral methods and X-ray crystallographic analysis.
Two new ent-kaurane diterpenoids, xerophilusin E (1) and xerophilusin F (2), were isolated from the leaves of Isodon xerophilus.Their structures were determined as 3, 20:7, 20 diepoxy-ent-kaur-16-en-15-one and 7β, 14β, 20 (R)-trihydroxy-11β-acetoxy-7, 20-cyclo-ent-kaur-16-en-6, 15-dione, respectively, by spectral methods and X-ray crystallographic analysis.
2000, 11(9): 799-802
Abstract:
The extract of E.coli containing recombinant human intcrferon-(rhIFN-) with 7.0 mol/L guanidine hydrochloride (Gu·HCl) was directly injeeted into a column of reverse phase liquid chromatography (RPLC) to scparatc and purify rhIFN-with acetic acid-water as mobile phase. Gu·HCl and most impure proteins can be scparatcd by this way.Compared with the usual dilution method, the bioactivity recovery of the purified rhIFN-was found to be over 500%.In addition, compared to common organic solvents cmploycd in RPLC, acetic acid has higher freezing point, and therefore, it is easy to concentrate the aim-irotcin by frcczc-drying when acetic acid-water is used as mobile phase in RPLC.
The extract of E.coli containing recombinant human intcrferon-(rhIFN-) with 7.0 mol/L guanidine hydrochloride (Gu·HCl) was directly injeeted into a column of reverse phase liquid chromatography (RPLC) to scparatc and purify rhIFN-with acetic acid-water as mobile phase. Gu·HCl and most impure proteins can be scparatcd by this way.Compared with the usual dilution method, the bioactivity recovery of the purified rhIFN-was found to be over 500%.In addition, compared to common organic solvents cmploycd in RPLC, acetic acid has higher freezing point, and therefore, it is easy to concentrate the aim-irotcin by frcczc-drying when acetic acid-water is used as mobile phase in RPLC.
2000, 11(9): 803-806
Abstract:
Key factors for capillary electrophoresis of amino acids with indirect ultraviolet detection were investigated.Buffer compositions and additives were found to be influential as expected, while buffer PH was shown to be particularly critical to the separation and detection. The effect of pH also depended on the electrophoretic mode used.Ways to obtain recurring and selective separations were suggested.
Key factors for capillary electrophoresis of amino acids with indirect ultraviolet detection were investigated.Buffer compositions and additives were found to be influential as expected, while buffer PH was shown to be particularly critical to the separation and detection. The effect of pH also depended on the electrophoretic mode used.Ways to obtain recurring and selective separations were suggested.
2000, 11(9): 807-808
Abstract:
The behaviour of the complexes of copper, lead, cadmium and antimony with salicylfluorone (SAF) adsorbed on HMDE has been investigated by derivative chrono potentiometry in NH3/NH4Cl.The dependence of the peak height on the dt/dE vs E curve on preconcentration time, the pH of solution and the constant reducing current are discussed.This method achieved the simultaneous determination of copper, lead, cadmium and antimony in human hair.
The behaviour of the complexes of copper, lead, cadmium and antimony with salicylfluorone (SAF) adsorbed on HMDE has been investigated by derivative chrono potentiometry in NH3/NH4Cl.The dependence of the peak height on the dt/dE vs E curve on preconcentration time, the pH of solution and the constant reducing current are discussed.This method achieved the simultaneous determination of copper, lead, cadmium and antimony in human hair.
2000, 11(9): 809-812
Abstract:
The electrochemical quartz crystal impedance system (EQCIS) has been used for the study of a partially immersed Au electrode in 0.2 mol/L NaClO4 aqueous solution.The influences of the immersed area and height of the electrode on the EQCIS responses were evaluated, showing the highest response sensitivity to liquid loading at the center of the piezoelectric quartz crystal electrode.The increase in the immersed height of the Au electrode at oxygen reduction potentials during potential cycling was measured by this technique.
The electrochemical quartz crystal impedance system (EQCIS) has been used for the study of a partially immersed Au electrode in 0.2 mol/L NaClO4 aqueous solution.The influences of the immersed area and height of the electrode on the EQCIS responses were evaluated, showing the highest response sensitivity to liquid loading at the center of the piezoelectric quartz crystal electrode.The increase in the immersed height of the Au electrode at oxygen reduction potentials during potential cycling was measured by this technique.
2000, 11(9): 813-814
Abstract:
A new type of dye-sensitized nanocrystalline solid state photovoltaic cell based on the wide band gap n-TiO2/p-Cul heterojunction was fabricated.Tetra-carboxyphenyl porphyrine (TPP-(COOH)4), squarylium cyanine derivative (SQ-(CH2)3-SO3Py+) and ruthenium bipyridyl complex (RuL2 (NCS)2) were used as photosensitizers.Larger photocurrents and photovoltages were shown in the cell sensitized by ruthenium bipyridyl complex and can be further increased by intercalation of a TiO2 thin underlayer.
A new type of dye-sensitized nanocrystalline solid state photovoltaic cell based on the wide band gap n-TiO2/p-Cul heterojunction was fabricated.Tetra-carboxyphenyl porphyrine (TPP-(COOH)4), squarylium cyanine derivative (SQ-(CH2)3-SO3Py+) and ruthenium bipyridyl complex (RuL2 (NCS)2) were used as photosensitizers.Larger photocurrents and photovoltages were shown in the cell sensitized by ruthenium bipyridyl complex and can be further increased by intercalation of a TiO2 thin underlayer.
2000, 11(9): 815-818
Abstract:
For monomer reactivity ratios study, the copolymerization of D, L-3-methylglycolide (MG) with glycolide (GA) or D,L-lactide (LA) was carried out in bulk to a certain low conversion in the presence of stannous octoate at 140℃.The copolymer compositions were determined by 1H NMR spectroscopy.The monomer reactivity ratios were evaluated by Fineman-Ross method, Kelen-Tüdös method and linear least-squares method.The monomer reactivity ratios of D,L-3-methylglycolide and glycolide or D,L-lactide are rmg=0.73, rga=1.47; rmg=1.71, rla=0.92, respectively.
For monomer reactivity ratios study, the copolymerization of D, L-3-methylglycolide (MG) with glycolide (GA) or D,L-lactide (LA) was carried out in bulk to a certain low conversion in the presence of stannous octoate at 140℃.The copolymer compositions were determined by 1H NMR spectroscopy.The monomer reactivity ratios were evaluated by Fineman-Ross method, Kelen-Tüdös method and linear least-squares method.The monomer reactivity ratios of D,L-3-methylglycolide and glycolide or D,L-lactide are rmg=0.73, rga=1.47; rmg=1.71, rla=0.92, respectively.
2000, 11(9): 819-822
Abstract:
A new self-assembled films of a functional dendritic molecule, hyperbranched conjugated poly (phenylene vinylene), is obtained through covalent bond linkage.The highly ordered and homogenous molecular films are obtained and characterized by UV-vis spectra, fluorescent spectra and atomic force microscopy.
A new self-assembled films of a functional dendritic molecule, hyperbranched conjugated poly (phenylene vinylene), is obtained through covalent bond linkage.The highly ordered and homogenous molecular films are obtained and characterized by UV-vis spectra, fluorescent spectra and atomic force microscopy.
2000, 11(9): 823-826
Abstract:
The solubility of Troeger's base (TB) in SC-CO2/CH3OH was measured at 308K in the pressure range of 8 to 13 MPa, and methanol concentration ranges from 0 to 20 mol%.The sohubility increases dranmatically with methanol concentration.Comparison of solubility in supcrcritical CO2 with and without 10 mol% CH3OH in the prcssure of 8 MPa at 308K implies that both curves are steep in the lowcr pressure range but become smooth as the pressure increases.
The solubility of Troeger's base (TB) in SC-CO2/CH3OH was measured at 308K in the pressure range of 8 to 13 MPa, and methanol concentration ranges from 0 to 20 mol%.The sohubility increases dranmatically with methanol concentration.Comparison of solubility in supcrcritical CO2 with and without 10 mol% CH3OH in the prcssure of 8 MPa at 308K implies that both curves are steep in the lowcr pressure range but become smooth as the pressure increases.
2000, 11(9): 827-830
Abstract:
The catalytic effects for the oxidative methylation of toluene with methane over the basic zeolite catalysts prepared by promoting KY, KX, KM, KZSM-5 or Kβ with alkali-metal bromides and alkali-metal oxides have been investigated comparatively.The alkali-metal bromides promoted substrates are more effective than the alkali-metal oxides promoted systems.Moreover, the NaBr promoted systems are more active than KBr promoted systems.The most effective catalytic system (8wt%NaBr)/KZSM-5 gave a toluene conversion as high as 76.3% and a total C8 selectivity of 76.4% (styrene/ethylbenzene=9.76) resulting in a total C8 yield of 58.3%.
The catalytic effects for the oxidative methylation of toluene with methane over the basic zeolite catalysts prepared by promoting KY, KX, KM, KZSM-5 or Kβ with alkali-metal bromides and alkali-metal oxides have been investigated comparatively.The alkali-metal bromides promoted substrates are more effective than the alkali-metal oxides promoted systems.Moreover, the NaBr promoted systems are more active than KBr promoted systems.The most effective catalytic system (8wt%NaBr)/KZSM-5 gave a toluene conversion as high as 76.3% and a total C8 selectivity of 76.4% (styrene/ethylbenzene=9.76) resulting in a total C8 yield of 58.3%.
2000, 11(9): 831-834
Abstract:
MTBPyP (meso-tetrakis (4-N-benzylpyridyl) porphyrin, M=H2, Zn) bearing positive charge has been shown to associate with SiW12O404- in water solution.The spectral evolution and Job's plots analyses reveal that the relatively stable aggregates contain equal numbers of MTBPyP4+ and SiW12O404-.
MTBPyP (meso-tetrakis (4-N-benzylpyridyl) porphyrin, M=H2, Zn) bearing positive charge has been shown to associate with SiW12O404- in water solution.The spectral evolution and Job's plots analyses reveal that the relatively stable aggregates contain equal numbers of MTBPyP4+ and SiW12O404-.
2000, 11(9): 835-838
Abstract:
A novel Pd (Ⅱ) Benzo-15-crown-5 complex[Na (B15C5)]2[Pd (SCN)4] has been isolated and characterized by IR and X-ray diffraction analysis.The crystal structure belongs to monoclinic, space group P21/n with cell dimensions, a=1.0164 (6), b=1.3743 (3), c=1.4987 (7) nm, β=95.248 (6)°, V=2.0847nm3, Z=2, F (000)=944, R=0.053, Rw=0.072.The compound consists of two[Na (B15C5)]+ complex cations and a [Pd (SCN)4]2- complex anion.Each sodium ion is coordinated by five crown ether oxygen atoms and one N atom from the SCN group of[Pd (SCN)4]2- to form stable neutral complex.
A novel Pd (Ⅱ) Benzo-15-crown-5 complex[Na (B15C5)]2[Pd (SCN)4] has been isolated and characterized by IR and X-ray diffraction analysis.The crystal structure belongs to monoclinic, space group P21/n with cell dimensions, a=1.0164 (6), b=1.3743 (3), c=1.4987 (7) nm, β=95.248 (6)°, V=2.0847nm3, Z=2, F (000)=944, R=0.053, Rw=0.072.The compound consists of two[Na (B15C5)]+ complex cations and a [Pd (SCN)4]2- complex anion.Each sodium ion is coordinated by five crown ether oxygen atoms and one N atom from the SCN group of[Pd (SCN)4]2- to form stable neutral complex.
2000, 11(9): 839-842
Abstract:
The encapsulation of a rare earth (RE) complex Eu (DBM)3phen in modified Si-MCM-41 with 3-aminopropyltriethoxysilane is reported for the first time.The luminescence intensity of the RE complex in the modified Si-MCM-41 is about 9 times as strong as in unmodified Si-MCM-41 and the luminescence of the RE complex in the modified Si-MCM-41 has good color purity.
The encapsulation of a rare earth (RE) complex Eu (DBM)3phen in modified Si-MCM-41 with 3-aminopropyltriethoxysilane is reported for the first time.The luminescence intensity of the RE complex in the modified Si-MCM-41 is about 9 times as strong as in unmodified Si-MCM-41 and the luminescence of the RE complex in the modified Si-MCM-41 has good color purity.
2000, 11(9): 843-846
Abstract:
This is the first report of using the microwave heating technique to synthesize calcium sulphide activated by europium whose structure is determined as the face-centered cubic by conventional X-ray powder diffraction method.The phosphor has maximum excitation peaks located at 280 nm and 560 nm and the maximum emission of the phosphor is 630 nm.When the concentration of Eu2+ in CaS increases from 1.0×10-5 to 1.0×10-2 mole per mole host, the body colour of the calcium sulphide activated with europium changes from white, through light-red to pink to deep-red.The phosphor obtains the longest afterglow at the concentration of 0.1% Eu2+-doped and is a kind of good material excited by sunlight.
This is the first report of using the microwave heating technique to synthesize calcium sulphide activated by europium whose structure is determined as the face-centered cubic by conventional X-ray powder diffraction method.The phosphor has maximum excitation peaks located at 280 nm and 560 nm and the maximum emission of the phosphor is 630 nm.When the concentration of Eu2+ in CaS increases from 1.0×10-5 to 1.0×10-2 mole per mole host, the body colour of the calcium sulphide activated with europium changes from white, through light-red to pink to deep-red.The phosphor obtains the longest afterglow at the concentration of 0.1% Eu2+-doped and is a kind of good material excited by sunlight.
