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2000 Volume 11 Issue 7
2000, 11(7): 567-570
Abstract:
Two practical methods for highly stereoselective synthesis of (Z)-2-acylamido-4-phenylcrotonates 2a~b have been developed. The key step in the first route was how to control the acid-catalyzed isomerization of condensation mixtures of α-keto ester 5 with carbomite. In the second route the key step was reduction of oxime 8, derived from α-keto ester 5, with iron powder in the presence of acetic anhydride.
Two practical methods for highly stereoselective synthesis of (Z)-2-acylamido-4-phenylcrotonates 2a~b have been developed. The key step in the first route was how to control the acid-catalyzed isomerization of condensation mixtures of α-keto ester 5 with carbomite. In the second route the key step was reduction of oxime 8, derived from α-keto ester 5, with iron powder in the presence of acetic anhydride.
2000, 11(7): 567-570
Abstract:
Synthesis of 4'-methoxyflavone, first by the reaction of 4-methoxy acetophenone enamine with heptanedioyl chloride, then by dehydrogenation, is described.
Synthesis of 4'-methoxyflavone, first by the reaction of 4-methoxy acetophenone enamine with heptanedioyl chloride, then by dehydrogenation, is described.
2000, 11(7): 571-572
Abstract:
We have designed and synthesized a series of new phthalimidopiperazines, biological activity test show that the target compounds(Ic, Ie, Ii) can inhibit HIV-1 RT with IC50 20.0, 43.8, and 63.7 μM, respectively.
We have designed and synthesized a series of new phthalimidopiperazines, biological activity test show that the target compounds(Ic, Ie, Ii) can inhibit HIV-1 RT with IC50 20.0, 43.8, and 63.7 μM, respectively.
2000, 11(7): 573-576
Abstract:
A new dinucleating 24-membered hexaazadiphenol macrocyclic ligand, 3,6,9,17,20, 23-hexaaza-29,30-dihydroxy-13,27-dimethyl-tricyclo[23, 3, 1, 111, 15] triaconta-1(28), 11,13, 15(30),25, 26-hexaene, BDBPH, was synthesized by the NaBH4 reduction of the Schiff-base obtained from the[2+2] condensation between diethylenetriamine and diformyl-p-cresol. The structure was characterized by elemental analysis, 1HNMR and FAB-MS. The synthetic method was also discussed.
A new dinucleating 24-membered hexaazadiphenol macrocyclic ligand, 3,6,9,17,20, 23-hexaaza-29,30-dihydroxy-13,27-dimethyl-tricyclo[23, 3, 1, 111, 15] triaconta-1(28), 11,13, 15(30),25, 26-hexaene, BDBPH, was synthesized by the NaBH4 reduction of the Schiff-base obtained from the[2+2] condensation between diethylenetriamine and diformyl-p-cresol. The structure was characterized by elemental analysis, 1HNMR and FAB-MS. The synthetic method was also discussed.
2000, 11(7): 577-580
Abstract:
Some cationic and neutral lipids bearing cholesteryl group were synthesized as gene vectors, and the structures of the compounds were characterized by IR, 1HNMR, MS and elemental analysis.
Some cationic and neutral lipids bearing cholesteryl group were synthesized as gene vectors, and the structures of the compounds were characterized by IR, 1HNMR, MS and elemental analysis.
2000, 11(7): 581-582
Abstract:
Fourteen N'-(4,5,6-Trisubstitued pyrimidin-2-yl)-2-chloroacetylureas and fourteen N-[N'-(4,5,6-trisubstitued pyrimidin-2-yl) acetylureido] benzoic sulfimide derivatives were synthesized. Among them twenty-seven are new compounds and their structures have been confirmed by 1HNMR, IR, MS and elemental analysis. The preliminary biological tests showed that some of the target compounds have excellent inhibitory activities against barnyard grass and rape, and the others have a good regulating activity for plant growth.
Fourteen N'-(4,5,6-Trisubstitued pyrimidin-2-yl)-2-chloroacetylureas and fourteen N-[N'-(4,5,6-trisubstitued pyrimidin-2-yl) acetylureido] benzoic sulfimide derivatives were synthesized. Among them twenty-seven are new compounds and their structures have been confirmed by 1HNMR, IR, MS and elemental analysis. The preliminary biological tests showed that some of the target compounds have excellent inhibitory activities against barnyard grass and rape, and the others have a good regulating activity for plant growth.
2000, 11(7): 583-586
Abstract:
A series of new stable (thermal and photochemical) ferrocenyl derivatives containing C=N bond and benzene ring in long conjugated chains have been synthesized and characterized by 1HNMR(400MHz), IR, and elemental analysis. Pull-push ferrocenyl complexes that we have prepared have strong NLO responses identified by electronic absorption spectrum.
A series of new stable (thermal and photochemical) ferrocenyl derivatives containing C=N bond and benzene ring in long conjugated chains have been synthesized and characterized by 1HNMR(400MHz), IR, and elemental analysis. Pull-push ferrocenyl complexes that we have prepared have strong NLO responses identified by electronic absorption spectrum.
2000, 11(7): 587-588
Abstract:
Three diphosphinites were synthesized for preparing rhodium-diphosphinite complexes. The complexes were used for asymmetric catalytic hydrogenation of amino acid precursor α-acetamidocinnamic acid and its methyl ester. With all complexes, D-amino acid is the most abundant product.
Three diphosphinites were synthesized for preparing rhodium-diphosphinite complexes. The complexes were used for asymmetric catalytic hydrogenation of amino acid precursor α-acetamidocinnamic acid and its methyl ester. With all complexes, D-amino acid is the most abundant product.
Catalytic Formation of Propylene Carbonate from Supercritical Carbon Dioxide/Propylene Oxide Mixture
2000, 11(7): 589-592
Abstract:
Propylene carbonate was synthesized from supercritical carbon dioxide (SC-CO2)/propylene oxide mixture with phthalocyaninatoaluminium chloride (ClAlPc)/tetrabutylammon-ium bromide (n-Bu4NBr) as catalyst. The high rate of reaction was attributed to rapid diffusion and the high miscibility of propylene oxide in SC-CO2 under employed conditions. Various reaction periods present different formation rate of propylene carbonate, mainly due to the existence of phase change during the reaction. The experimental results demonstrate that SC-CO2 could be used as not only an environmentally benign solvent but also a carbon precursor in synthesis.
Propylene carbonate was synthesized from supercritical carbon dioxide (SC-CO2)/propylene oxide mixture with phthalocyaninatoaluminium chloride (ClAlPc)/tetrabutylammon-ium bromide (n-Bu4NBr) as catalyst. The high rate of reaction was attributed to rapid diffusion and the high miscibility of propylene oxide in SC-CO2 under employed conditions. Various reaction periods present different formation rate of propylene carbonate, mainly due to the existence of phase change during the reaction. The experimental results demonstrate that SC-CO2 could be used as not only an environmentally benign solvent but also a carbon precursor in synthesis.
2000, 11(7): 593-594
Abstract:
A new cyclic peptide named polycarponin A, was isolated from the whole plants of Polycarpon prostratum. Its structure was determined by detailed spectroscopic analysis.
A new cyclic peptide named polycarponin A, was isolated from the whole plants of Polycarpon prostratum. Its structure was determined by detailed spectroscopic analysis.
2000, 11(7): 595-596
Abstract:
A new cyclopeptide, brachystemin A, has been isolated from the roots of Brachystemma calycinum. The structure was elucidated by spectral methods.
A new cyclopeptide, brachystemin A, has been isolated from the roots of Brachystemma calycinum. The structure was elucidated by spectral methods.
2000, 11(7): 597-600
Abstract:
The anti-tumor activity of Trichosanthin (TCS) has been frequently reported in recent years. In our experiments, electrochemical methods were applied to detect the effects of TCS on human leukemia cells U937. 50μg/ml TCS treatment for 40 hours can cause irreversible negative effects on the viability of U937 cells. This effect largely depends on the concentration of TCS and the time period of treatment.
The anti-tumor activity of Trichosanthin (TCS) has been frequently reported in recent years. In our experiments, electrochemical methods were applied to detect the effects of TCS on human leukemia cells U937. 50μg/ml TCS treatment for 40 hours can cause irreversible negative effects on the viability of U937 cells. This effect largely depends on the concentration of TCS and the time period of treatment.
2000, 11(7): 601-602
Abstract:
With a Ni/GC ion implantation modified electrode as working electrode, in 0.1 mol/L HOAc-NaOAc (pH=4.62) solution, a sensitive reductive wave of ADM was obtained by linear sweep voltammetry. The peak potential was-0.55 V (vs.SCE). The peak current is proportional to the concentration of ADM with a detection limit of 6.9×10-8 mol/L. The behavior of the reduction wave was studied. The experiments of AES and XPS showed that Ni was surely implanted into the surface of the GCE and the implanted Ni at the GCE improved the electrocatalytic activity.
With a Ni/GC ion implantation modified electrode as working electrode, in 0.1 mol/L HOAc-NaOAc (pH=4.62) solution, a sensitive reductive wave of ADM was obtained by linear sweep voltammetry. The peak potential was-0.55 V (vs.SCE). The peak current is proportional to the concentration of ADM with a detection limit of 6.9×10-8 mol/L. The behavior of the reduction wave was studied. The experiments of AES and XPS showed that Ni was surely implanted into the surface of the GCE and the implanted Ni at the GCE improved the electrocatalytic activity.
2000, 11(7): 603-604
Abstract:
A nested genetic algorithm, including genetic parameter level and genetic implemented level for peak parameters, was proposed and applied for resolving overlapped spectral bands. By the genetic parameter level, parameters of genetic algorithm were optimized; moreover, the number of overlapped peaks was determined simultaneously. Then parameters of individual peaks were computed with the genetic implemented level.
A nested genetic algorithm, including genetic parameter level and genetic implemented level for peak parameters, was proposed and applied for resolving overlapped spectral bands. By the genetic parameter level, parameters of genetic algorithm were optimized; moreover, the number of overlapped peaks was determined simultaneously. Then parameters of individual peaks were computed with the genetic implemented level.
2000, 11(7): 605-608
Abstract:
A new method was developed for the quantitative determination of the neurotoxic non-protein amino acid, 3-N-oxalyl-L-2,3-diaminopropionic acid (β-ODAP), its nontoxic α-isomer and other non-protein amino acids in the plant samples of Lathyrus sativus after derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) by reversed-phase high-performance liquid chromatography (HPLC). 2-Amino butyric acid (ABA) was used as an internal standard. The RP HPLC detection limit for both isomers is 1.8 ng with good response linearity. The results are compared with a colorimetric method.
A new method was developed for the quantitative determination of the neurotoxic non-protein amino acid, 3-N-oxalyl-L-2,3-diaminopropionic acid (β-ODAP), its nontoxic α-isomer and other non-protein amino acids in the plant samples of Lathyrus sativus after derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) by reversed-phase high-performance liquid chromatography (HPLC). 2-Amino butyric acid (ABA) was used as an internal standard. The RP HPLC detection limit for both isomers is 1.8 ng with good response linearity. The results are compared with a colorimetric method.
2000, 11(7): 609-612
Abstract:
The use of solid phase spectrophotometry for the determination of trace phosphorus in the system of phosphomolybdate-fructose is described. The adsorption of the system on anion-exchange resin is reported.
The use of solid phase spectrophotometry for the determination of trace phosphorus in the system of phosphomolybdate-fructose is described. The adsorption of the system on anion-exchange resin is reported.
2000, 11(7): 613-614
Abstract:
Polarization variable-angle synchronous fluorescence spectrometry was proposed to determine samples in turbid solution. A mixture of fluorescein, rhodamine 6G and rhodamine B was used to evaluate the technique. The background caused by scattering light was decreased remarkably. The limits of detection were 0.6 ng/ml for fluorescein, 2.3 ng/ml for rhodamine 6G and 4.1 ng/ml for rhodamine B, respectively.
Polarization variable-angle synchronous fluorescence spectrometry was proposed to determine samples in turbid solution. A mixture of fluorescein, rhodamine 6G and rhodamine B was used to evaluate the technique. The background caused by scattering light was decreased remarkably. The limits of detection were 0.6 ng/ml for fluorescein, 2.3 ng/ml for rhodamine 6G and 4.1 ng/ml for rhodamine B, respectively.
2000, 11(7): 615-616
Abstract:
A new method of oscillographic chronopotentiometry at silver disk electrode was investigated.By using it, a series of ions such as Pb, In, Cr, Tl, Bi etc. were determined. The detection limits are two or three orders of magnitude lower than those by oscillographic chronopotentiometry at mercury electrode. The proposed method is characterized by fine sensitivity、stable oscillogram and no mercury. The research on the mechanism of this method shows that these achievements are caused by the characterristics of silver electroxidation and electroreduction and the oscillographic chronopotentiometry (OC).
A new method of oscillographic chronopotentiometry at silver disk electrode was investigated.By using it, a series of ions such as Pb, In, Cr, Tl, Bi etc. were determined. The detection limits are two or three orders of magnitude lower than those by oscillographic chronopotentiometry at mercury electrode. The proposed method is characterized by fine sensitivity、stable oscillogram and no mercury. The research on the mechanism of this method shows that these achievements are caused by the characterristics of silver electroxidation and electroreduction and the oscillographic chronopotentiometry (OC).
2000, 11(7): 617-620
Abstract:
In this paper a pH microprobe technique was developed to measure in-situ the pH value at the electrode/solution interface. Iridium oxide was used as a pH sensitive material with good response behavior in the measured solutions. The experimental results indicated that the interfacial pH increased with the applied potential, first jumped to a maximum, then slowly decreased at the controlled potential during the electrodeposition process of functional ceramics.
In this paper a pH microprobe technique was developed to measure in-situ the pH value at the electrode/solution interface. Iridium oxide was used as a pH sensitive material with good response behavior in the measured solutions. The experimental results indicated that the interfacial pH increased with the applied potential, first jumped to a maximum, then slowly decreased at the controlled potential during the electrodeposition process of functional ceramics.
2000, 11(7): 621-622
Abstract:
Talc coatings were produced with chemical method on the surface of pure aluminum. The characteristics of cathodic polarization in a 3.5% NaCl solution have been studied through the observation of the ‘current oscillations’ phenomenon.
Talc coatings were produced with chemical method on the surface of pure aluminum. The characteristics of cathodic polarization in a 3.5% NaCl solution have been studied through the observation of the ‘current oscillations’ phenomenon.
2000, 11(7): 623-626
Abstract:
Grand Canonical Monte Carlo (GCMC) simulations have been performed to study the localization and adsorption behavior of benzene and propylene, in purely siliceous MWW zeolite (ITQ-1). By analyzing the locations of benzene and propylene in ITQ-1, it can be deduced that the alkylation of benzene and propylene will mainly happen in 12-MR supercages at the external surface or close to the external surface. The adsorption isotherms of benzene and propylene at 315K and 0~3.5kPa are predicted, and the results for benzene generally coincide with the trend from the experiments of a series of aromatic compounds.
Grand Canonical Monte Carlo (GCMC) simulations have been performed to study the localization and adsorption behavior of benzene and propylene, in purely siliceous MWW zeolite (ITQ-1). By analyzing the locations of benzene and propylene in ITQ-1, it can be deduced that the alkylation of benzene and propylene will mainly happen in 12-MR supercages at the external surface or close to the external surface. The adsorption isotherms of benzene and propylene at 315K and 0~3.5kPa are predicted, and the results for benzene generally coincide with the trend from the experiments of a series of aromatic compounds.
2000, 11(7): 627-630
Abstract:
Self-organization of PbS into quantum dots superlattices is demonstrated for the first time, and hexaplanar colloidal crystals 1-10μm in size made from PbS quantum dots 4nm in diameter are shown in Transmission Electron Microscope (TEM) micrograph, and the inner structures of the superlattices can be seen from the High Resolution Transmission Electron Microscope (HRTEM).
Self-organization of PbS into quantum dots superlattices is demonstrated for the first time, and hexaplanar colloidal crystals 1-10μm in size made from PbS quantum dots 4nm in diameter are shown in Transmission Electron Microscope (TEM) micrograph, and the inner structures of the superlattices can be seen from the High Resolution Transmission Electron Microscope (HRTEM).
2000, 11(7): 631-634
Abstract:
CH4-CO2-O2 reforming to syngas in a novel Ba0.5Sr0.5Co0.8Fe0.2O3-δ oxygen-permeable membrane reactor using LiLaNiO/γ-Al2O3 as catalyst was successfully reported. Excellent reaction performance was achieved with around 92% methane conversion efficiency, 95% CO2 conversion rate, and nearly 8.5mL/min·cm2 oxygen permeation flux. In contrast to the oxygen permeation model with the presence of large concentration of CO2 (under such condition the oxygen permeation flux deteriorates with time), the oxygen permeation flux is really stable under the CH4-CO2-O2 reforming condition.
CH4-CO2-O2 reforming to syngas in a novel Ba0.5Sr0.5Co0.8Fe0.2O3-δ oxygen-permeable membrane reactor using LiLaNiO/γ-Al2O3 as catalyst was successfully reported. Excellent reaction performance was achieved with around 92% methane conversion efficiency, 95% CO2 conversion rate, and nearly 8.5mL/min·cm2 oxygen permeation flux. In contrast to the oxygen permeation model with the presence of large concentration of CO2 (under such condition the oxygen permeation flux deteriorates with time), the oxygen permeation flux is really stable under the CH4-CO2-O2 reforming condition.
2000, 11(7): 635-638
Abstract:
Two new binuclear (europium and lanthanum) β-diketone complexes Eu0.9La0.1(TTA)3Phen and Eu0.5La0.5(TTA)3Phen in which Phen is 1,10-phenanthroline, TTA is an anion of thenoyltrifluoroacetone (HTTA) were synthesized for the first time. They showed intense photoluminescence (PL) and mechanoluminescence (ML), and had their maximum PL and ML spectra peaked at 613.5 nm with half bandwidth of 10 nm respectively. Their PL and ML intensity were obviously stronger than these from Eu(TTA)3Phen. It is considered that binuclear (europium and lanthanum) β-diketones complexes are promising ML and PL materials.
Two new binuclear (europium and lanthanum) β-diketone complexes Eu0.9La0.1(TTA)3Phen and Eu0.5La0.5(TTA)3Phen in which Phen is 1,10-phenanthroline, TTA is an anion of thenoyltrifluoroacetone (HTTA) were synthesized for the first time. They showed intense photoluminescence (PL) and mechanoluminescence (ML), and had their maximum PL and ML spectra peaked at 613.5 nm with half bandwidth of 10 nm respectively. Their PL and ML intensity were obviously stronger than these from Eu(TTA)3Phen. It is considered that binuclear (europium and lanthanum) β-diketones complexes are promising ML and PL materials.
2000, 11(7): 639-640
Abstract:
A new dinuclear copper (Ⅱ) complex containing 3-ferrocenyl-2-crotomic acid salt (FCA) and phen has been synthesized. Its structure was characterized by X-ray crystal analysis. The molecular is a pentametallic compound.
A new dinuclear copper (Ⅱ) complex containing 3-ferrocenyl-2-crotomic acid salt (FCA) and phen has been synthesized. Its structure was characterized by X-ray crystal analysis. The molecular is a pentametallic compound.
2000, 11(7): 641-644
Abstract:
An unbridged zirconocene complex bis(1,2-diphenylcyclopentadienyl)zirconium dichloride[(1,2-Ph2-C5H3)2ZrCl2] 1 has been synthesized and structurally characterized. When activated by MAO, 1 produces ultra-high molecular weight polyethylene with high melting transition temperature, as well as atactic oligopropylene with average molecular weight of ~1150 g mol-1.
An unbridged zirconocene complex bis(1,2-diphenylcyclopentadienyl)zirconium dichloride[(1,2-Ph2-C5H3)2ZrCl2] 1 has been synthesized and structurally characterized. When activated by MAO, 1 produces ultra-high molecular weight polyethylene with high melting transition temperature, as well as atactic oligopropylene with average molecular weight of ~1150 g mol-1.
2000, 11(7): 645-648
Abstract:
The novel complex of Mn(V):Mn·3/2(μ-DHBQ)·4H2O·2Cl (where, H2DHBQ=2,5-dihydroxyl-1,4-benzoquinone) was synthesized and its crystal structure has been determined by X-ray diffraction. The complex belongs to trigonal system with space group P3(#147), a=1.415(2) nm, c=0.6552(4) nm, V=1.1371(7) nm-3, Z=2, Dx=1.183 g/cm3, μ=7.37 cm-1, F(000)=408.00, R=0.041, Rw=0.046.
The novel complex of Mn(V):Mn·3/2(μ-DHBQ)·4H2O·2Cl (where, H2DHBQ=2,5-dihydroxyl-1,4-benzoquinone) was synthesized and its crystal structure has been determined by X-ray diffraction. The complex belongs to trigonal system with space group P3(#147), a=1.415(2) nm, c=0.6552(4) nm, V=1.1371(7) nm-3, Z=2, Dx=1.183 g/cm3, μ=7.37 cm-1, F(000)=408.00, R=0.041, Rw=0.046.
2000, 11(7): 649-652
Abstract:
Coating MgO or ZrO2 on zeolite NaY accelerated decomposition of N-nitrosodimethylamine and N-nitrosopyrrolidine, resulting from variation of the surface state such as generation of basic sites.
Coating MgO or ZrO2 on zeolite NaY accelerated decomposition of N-nitrosodimethylamine and N-nitrosopyrrolidine, resulting from variation of the surface state such as generation of basic sites.
2000, 11(7): 653-654
Abstract:
The extraction behavior of Sm(Ⅲ), Eu(Ⅲ),Er(Ⅲ) and Yb(Ⅲ) with 1-nitroso-2-naphthol (HA) in paraffin has been studied. The composition of extracted complexes has been determined to be LnA3 by slope analysis method. The effect of temperature on extraction system is also investigated and thermodynamic parameters are obtained.
The extraction behavior of Sm(Ⅲ), Eu(Ⅲ),Er(Ⅲ) and Yb(Ⅲ) with 1-nitroso-2-naphthol (HA) in paraffin has been studied. The composition of extracted complexes has been determined to be LnA3 by slope analysis method. The effect of temperature on extraction system is also investigated and thermodynamic parameters are obtained.
2000, 11(7): 655-658
Abstract:
This paper presents a computer model to investigate the buffering function of aluminum being in equilibrium with mineral kaolinite in acidic natural water. Factors affecting the theoretical pH values are discussed. The model is verified by analyzing practical water samples.
This paper presents a computer model to investigate the buffering function of aluminum being in equilibrium with mineral kaolinite in acidic natural water. Factors affecting the theoretical pH values are discussed. The model is verified by analyzing practical water samples.
