1999 Volume 10 Issue 10

Studies on the Reactionof Substituted 6-Nitrocoumarin with Anilines
Long Fei XIE , Shi Ping XU , Song XU , Lan Min LI
1999, 10(10): 811-812
[Abstract](162) [FullText HTML] [PDF 63KB](0)
Abstract:
3-Acetyl-7-hydroxy-8-methyl-6-nitrocoumarin reacted with substituted anilines, and fission of the heterocyclic ring occurred.
Synthesis of α-Aminoarylacetic Acids in the Presenceof Phase Transfer Catalysts
Wei Liang XU , You Fang CHEN , Fei Long WU
1999, 10(10): 813-816
[Abstract](162) [FullText HTML] [PDF 127KB](0)
Abstract:
Synthesis of α-aminoarylacetic acids with good yield in the presence of phase transfer catalyst (PTC) under sonication has been studied. Results obtained are superior to those by other similar methods. The data show that β-cyclodextrin(β-CD) is a more efficient catalyst than other PTC. Optimum reaction conditions and a preliminary mechanism are also discussed.
Synthesis of Amurensin H, a New Resveratrol Dimerfrom the Roots of Vitis Amurensis
Kai Sheng HUANG , Mao LIN , Ying Hong WANG
1999, 10(10): 817-820
[Abstract](166) [FullText HTML] [PDF 97KB](1)
Abstract:
Amurensin H(1) is a new resveratrol dimer isolated from the roots of Vitis amurensis Rupr. Its structure was determined by spectroscopic methods. It was synthesized from resveratrol with an oxidative coupling reaction as a key step.
An Efficient Synthesis and Screening of Osteostatin analogues byUsing Pooling Strategy
De Xin WANG , Rui HAN , Hong Yan LIU , Lei HUANG , Jun FU
1999, 10(10): 821-824
[Abstract](160) [FullText HTML] [PDF 110KB](0)
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An efficient synthesis and screening of twenty one osteostatin(OSN) analogues were achieved by using pooling strategy. Three analogues were found to retain almost the same activity of inhibiting bone resorption in rat as that of OSN. Therefore, it is possible to develop partially modified OSN surrogate with higher enzymic stability.
A New Sesquiterpene from Celastrus Angulatus
Hai Lin QIN , Tian Zeng ZHAO , Yu Jun SHANG
1999, 10(10): 825-826
[Abstract](169) [FullText HTML] [PDF 96KB](0)
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One new sesquiterpene polyol ester named angulatin C was isolated from the root bark of Celastrus angulatus along with a known compound, angulatin B.Their structures were elucidated on the basis of spectral analysis.
New Diterpenoid Alkaloids from Spiraea fritschiana var. parvifolia
Min LI , Xiu Bao DU , Yue Mao SHEN , Bin Gui WANG , Xiao Jiang HAO
1999, 10(10): 827-830
[Abstract](158) [FullText HTML] [PDF 104KB](0)
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Two new C20 hetisine-type diterpenoid alkaloids, spirafine Ⅲ (1) and spirafine Ⅱ (2), were isolated from the roots of spiraea fritschiana var. parvifolia. Their structures were elucidated based on HRMS, IR and NMR spectral data, and chemical reaction.
Carboxymethyl-β-Cyclodextrin for Chiral Separation of Basic Drugsby Capillary Elcctrophoresis
Wei WANG , Xiao Yun FU , Yao Zu CHEN
1999, 10(10): 831-832
[Abstract](155) [FullText HTML] [PDF 98KB](0)
Abstract:
Four basic drugs were separated by capillary electrophoresis (CE) using carboxymethyl-β-cyclodextrin (CM-β-CD) as chiral selector The effects of CM-β-CD concentration, applied voltage, operation temperature were investigated. Under the selected conditions; norephedrine, ofloxacin; terbutaline and chlorpheniramine were enantiomerally baseline-separated using H3P04-triethanolamine buffer at pH 3 containing 10, 5.5, 2, 2mmo1/L CM-β-CD respectively.
Fragmentation Reactions of Adduct Ions [M+CH3CO]+ of IsomericPhenylenediamines
Zhi Li LI , Shu Ying LIU , Long Sheng LONG
1999, 10(10): 833-834
[Abstract](190) [FullText HTML] [PDF 90KB](0)
Abstract:
The dissociation routes of the adduct ions [M+CH3CO]+ formed by ion-molecule reaction of isomeric phenylenediamines with acetyl ion from acetone under chemical ionisation condition were investigated by using collision-induced dissociation (CID) technique performed at ion kinetic energies of 40eV. The adduct ions are intermediate ion-neutral complexes.
Theoretical Study on the Structure and Vibrational Spectra for4-methyl-3-penten-2-one
Dong Mei DU , Ai Ping FU , Zheng Yu ZHOU
1999, 10(10): 835-838
[Abstract](158) [FullText HTML] [PDF 191KB](0)
Abstract:
Density functional theory BLYP (using Becke's and Lee-Yang-Parr's correlation functionals),ab initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibrational spectra of 4-methyl-3-penten-2-one. The BLYP/6-31G* and scaled HF/6-31G* frequencies correspond well with each other and with available experimental assignment of the functional vibrational modes.
19F NMR Study on the Charge-Transfer Process between Ground-State Acceptor Fluoranil (or Pentafluorophenyl Carboxylate) andSome N-Alkylphenothiazine Donors
Hu Nan YI , Ji Liang SHI , Zhi Hai QIU , Jia Yi XU , Xi Kui JIANG
1999, 10(10): 839-842
[Abstract](156) [FullText HTML] [PDF 145KB](0)
Abstract:
The line positions of 19F NMR absorption of fluoranil (TFQ) or pentafluorophenyl carboxylate (PFE-16) in the presence of N-alkylphenothiazine donors have been measured. By comparing the 19F chemical shift in C6D6 of TFQ or PFE-16 in the absence of the donor with those in the presence of the: donor. the difference of these chemical shifts was found to be large. In the presence of the donor, 19F upheld shifts of TFQ or PFE-16 have been observed. The experimental results showed that there is a charge-transfer process between TFQ or PFE-16 and the donor. When TFQ or PFE-16 accepts the charge from the donor, its 19F resonance moves upheld.
Photoreduction Behaviors of Micropcroxidase-11 Adsorbed on the Roughened Silver Electrodes
Ying GAO , Hui YANG , Ji Dong GUO , Jun Wei ZHENG , Tian Hong LU
1999, 10(10): 843-844
[Abstract](176) [FullText HTML] [PDF 101KB](0)
Abstract:
It was found that microperoxidase-11 (MP-11) can undergo photoreduction at the bare roughened silver electrode. No photoreduction happens at the roughened silver electrode modified with mercaptoundecanoic carboxylic acid/poly-lysine. The photoreduction mechanism is discussed.
Dioxygen Affinities and Biomimetic Catalytic Performance ofTransition-metal Complexes with Benzoin Schiff Bases
Hua YANG , Sheng Ying QIN , Xiao Xia LU , Wei ZENG
1999, 10(10): 845-848
[Abstract](167) [FullText HTML] [PDF 138KB](1)
Abstract:
The oxygenation constants of transition-metal complexes with benzoin Schiff bases were measured and these complexes were first employed as models for mimicking monooxygenase in catalytic epoxidation of styrene. The highest conversion and selectivity were up to 39.6% and 100% respectively at ambient temperature and pressure. The effects of structures of the bridge group R in the ligands on the dioxygen amities and catalytic activities to epoxidize styrene were also investigated.
A new enzymatic method for determination of E. coli
Yun Xiang CI , Tian Le LI
1999, 10(10): 849-850
[Abstract](159) [FullText HTML] [PDF 96KB](0)
Abstract:
β-Galactosidase, a kind of endoenzyme in E. coli cells, can be released by the poreforming action of colicin E1, and E.coli can be detected rapidly by enzymatic method.
Study on the Spectrophotometric Determination of Rare Earths with a New Chromogenic Reagent Dibromo-p-methyl-chlorosulfonazo(DBMCSA)
Guo Zhen FANG , Jiao PAN , Wei Liang AHOU , Bu Lu XU
1999, 10(10): 851-854
[Abstract](157) [FullText HTML] [PDF 179KB](1)
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A new method for the determination of cerium subgroup rare earths was studied and reported in this paper. It was found that cerium subgrouo rare earth elements react with DBMCSA in 0.6 mol/L hydrochloric acid medium to form stable blue complexes. absorbances of eyual amounts of cerium subgroup rare earths are close to each other at their maximum adsorptive wavelength (641 nm). Beer's law is obeyed for 0-20 μg of rare earths in 25 ml of solution. The method has been applied to the determination of the total amount of cerium subgroup rare earths in steel and cast iron samples with satisfactory results.
The Electrochemical Behavior of Bleomycin at A Co/GC IonImplantation Modified Electrode
Jing Bo HU , Qi Long LI
1999, 10(10): 855-856
[Abstract](164) [FullText HTML] [PDF 76KB](0)
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In 0.10mol/L HOAc-NaOAc buffer solution (pH 4.59), a sensitive reduction peak of bleomycin is obtained by linear sweep voltammetry at Co/GC ion implantation modified electrode. Its electrochemical behavior has been studied. The experiments of AES and XPS Show that Co is surely implanted into the surface of GCE and improved the electrocatalytic activity.
Unique Nafion-Os(bpy32+ Modified Electrodes
Pei Fang LIU , Jun Tao LU , Jia Wei YAN
1999, 10(10): 857-860
[Abstract](170) [FullText HTML] [PDF 176KB](0)
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It was newly found that the electrodes modified by applying ethanol solutions of Nation containing Os(bpy)32+ onto the substrate electrode (the one=step method) show two pairs of stable redox peaks of Os(bpy)32+/3+ on cyclic voltammogram near 0.54V and 0.25V, respectively. These modified electrodes can effectively mediate and catalyze the first and second steps of nitrite reduction in acidic media in the potential region 0-0.9V when the loading in the coating (X=Γ(Os2+)/Γ(S03+)) and pH in solution are below 0.17 and 4, respectively. When X is between 0.33 and 0.17, only the current peak near 0.54V appears regardless of solution pH and only the first step of NO2+ reduction is catalyzed. Thus the modified electrode provides a very useful flexibility that one can control the reaction pathway and catalytic activity of nitrite reduction by simply changing the concentration of the mediator in the coating.
Studies on Alternating Pulse Current-ChronopotentiometricStripping Analysis
Ke Qi YU , Jie HU , Hong Sheng TANG , Hong GAO
1999, 10(10): 861-862
[Abstract](156) [FullText HTML] [PDF 79KB](0)
Abstract:
Alternating pulses current一chronopotentiometric stripping analysis (APC-CPSA) is a new method as a variant of chronopotentiometric stripping analysis (CPSA). During the stripping step an alternating pulse current with a high frequency in a square wave mode is imposed on the electrode system. Thus, τ and sensitivity of APC-CPSA is increased a lot. The τ, E~t equation and its reciprocal derivative equation for APC-CPSA are derived and verified by the experimental results.
Electrocatalytic Oxidation of Hypophosphite on Nickel Electrode--In Situ UV-Vis Spectroscopic study
Yue ZENG , Shao Min ZHOU
1999, 10(10): 863-866
[Abstract](166) [FullText HTML] [PDF 185KB](0)
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The electrocatalytic oxidation of hypophosphite on a nickel electrode has been studied by means of in situ UV-Vis subtractive reflectance spectroscopy. An absorbency band around 245 nm, which was ascribed to the formation of an intermediate,· PHO2-, was observed in the electrocatalytic oxidation process. Accordingly, the electrocatalytic oxidation of hypophosphite might undergo a H abstraction of hypophosphite from the P-H bond to form the phosphoruscentred radical, · PHO2-, which is subsequently electrooxidized to the final product, phosphite.
Rheological Behavior of Epoxy Resin Concentrated Dispersions
Zhen Zhong YANG , Wei Wei WANG , De Lu ZHAO , Mao XU
1999, 10(10): 867-870
[Abstract](170) [FullText HTML] [PDF 191KB](0)
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For the concentrated dispersions of epoxy resin prepared by phase inversion emulsification technique, the effects of solid content and temperature on the rheological behavior are studied. It is found that there exists reversible structural transition in concentrated dispersions subjected to shearing. The viscosity oscillation correlated with high viscoelasticity at lower stress is remarkable in highly concentrated dispersions. There exists storage modules overshot at higher stress during the dynamic stress time ramp test. This could provide some information on dynamics of structure changes during shear action. Besides, the effects of solid content and temperature on the relationship between tangent delta and frequency are essentially different.
Polymerization of Styrene in Supercritical CO2-swollenPoly(ethylene terephthlate)
Dan LI , Bu Xing HAN , Hai Ke YAN
1999, 10(10): 871-872
[Abstract](165) [FullText HTML] [PDF 83KB](0)
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Polystyrene/Poly(ethylene terephthlate) (PET) blends have been prepared by the heterogeneous free-radical polymerization of styrene within supercritical carbon dioxide-swollen PET substrates. Composition of the blends and the averaQ molecular weight of polystyrene in the blends can be controlled by equilibration time and reaction condition.
Constant-Volume Heat Capacity of Mixed Supercritical Fluids andMolecular Interaction in the Systems
Lei SHI , Xi Feng ZHANG , Xiao Gang ZHANG , Bu Xing HAN , Guan Ying YANG , Hai Ke YAN
1999, 10(10): 873-874
[Abstract](168) [FullText HTML] [PDF 99KB](0)
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Constant-volume heat capacities of supercritical (SC) CO2, SC CO2-n-pentane, and SC CO2-n-heptane mixtures were determined at 308.15 K in the pressure range from 6 to 12 MPa. It was found that there is a maximum in each heat capacity vs pressure curve. Intermolecular interaction in the fluids was studied.
The Reaction Of Metal Trialkyls With Benzo[H]Quinolin-10-ol
Xue Song WU , Hong Sui SUN , Yi PAN , Hua Bing CHEN , Xiang Zhen SUN
1999, 10(10): 875-878
[Abstract](168) [FullText HTML] [PDF 163KB](0)
Abstract:
The reaction of the trialkyl metals (R3M, R=Me, Et; M=Ga, In) with henzo[h]quinolin-10-ol] (HO-BQ) in a 1:1 molar ratio gave intramolecular N coordinated complexes R2M-O-BQ (M=Ga, R=Me 1, Et 2) and (R2In-O-BQ)2 (M=In, R=Et 3,)in 80-90% yield. The molecular structures of complexes 1 and 3 have been established by X-ray crystallography.
Synthesis and Crystal Structure of Rare Earth Complex with Ciprofloxacin
Pin YANG , Jia Bin LI , Yan Ni TIAN , Kai Bei YU
1999, 10(10): 879-880
[Abstract](172) [FullText HTML] [PDF 78KB](0)
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The complex of rare earth with ciprofloxacin has been synthesized and characterized by means of x-ray single crystal diffraction. The structure features of the complex are decribed.
Synthesis and Properties of Three Tris(1,10-phenanthroline) ruthenium (Ⅱ) Derivatives
Fa Ming TIAN , Peng WANG , Guo Yi ZHU
1999, 10(10): 881-884
[Abstract](168) [FullText HTML] [PDF 134KB](3)
Abstract:
Three new asymmetrical ruthenium (Ⅱ) complexes: [Ru(phen)2{phen-NHCO(CH2)4Br}](PF6)2, [Ru(phen)2{phen-NHCO(CH2)5Br}](PF6)2 and [Ru(phen)2{phen-NHCO(CH2)10Br}](PF6)2 were synthesized, which were confirmed by the technique of FT-IR, 1H NMR and ESI-MS. The electrochemical and fluorescent properties of three Ru (Ⅱ) complexes were investigated with cyclic voltammetry and fluorometry.
In-situ Synthesis of ZSM-5 with Different Si/AlRatios on Honeycombshaped Cordierite and their Behavior on NO Decomposition
Xue Lei SHAN , Nai Jia GUAN , Xiang ZENG , Shou He XIANG
1999, 10(10): 885-888
[Abstract](166) [FullText HTML] [PDF 233KB](0)
Abstract:
Zeolites ZSM-5 with different Si/Al ratios were in-situ synthesized on the surface of honeycomb-shaped cordierite support for the first time. Characterizations of XRD and SEM were performed and it has been proved that the zeolite ZSM-5 was grown on the surface of the cordierite homogeneously. NO decomposition on the Cu exchanged ZSM-5/cordierite monolith catalysts was also studied. It was found that the monolith catalysts have a fine initial activity at 673K and GHSV of 10,000h-1. Such method should be a good way to make auto exhaust converter with monolith catalyst for NOx removal.
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