1993 Volume 4 Issue 9

A CONVENIENT ASYMMETRIC SYNTHESIS OF 1-AMINOALKYLPHOSPHONIC ACIDS
Cheng Ye YUAN , Shu Sen LI , Guo Quan WANG , Hao WU
1993, 4(9): 753-756
[Abstract](152) [FullText HTML] [PDF 145KB](0)
Abstract:
A convenient method for the asymmetric synthesis of 1-aminoalkylphosphonic acids was described.It involved the diastereoselctive alkylation of bicyclic chloromethylphosphonamide derived from (S)-2-ani-linomethylpyrrolidine followed by subsequent conversions leading to amino compounds by Staudinger method.Acid hydrolysis afforded the target molecule in good yield.
A MILD AND REGIOSPECIFIC OXIRANE RING OPENING TO PRECURSORS FOR PROSTANOID CONGENERS
Ai Lian ZHENG , Yuan Liu WU
1993, 4(9): 757-758
[Abstract](153) [FullText HTML] [PDF 90KB](0)
Abstract:
A stereoselective and regiospecific synthesis of procursors (2),(4),(6) and (7) of prostacyclin analogues from 2, 3-epoxylbicyclo[3.2.0]hept-6-one (1) are described.
α-OXOKETENE CYCLIC DITHIOACETAL CHEMISTRY(XⅢ)-THE ETHERIFYING REACTION ON THE ADDUCTS OF ALIPHATIC α-OXO KETENE CYCLIC DITHIOACETALS WITH ALLYL MAGNESIUM BROMIDE
Zai Ming ZHU , Qun LIU , Zhi Yun YANG
1993, 4(9): 759-762
[Abstract](154) [FullText HTML] [PDF 106KB](0)
Abstract:
Aliphatic α-oxo ketene cyclic dithioacetals 1 were reacted with allyl magnesium bromide to afford the 1, 2-addition products 2.Catalyzed by boron trifluoride etherate, the adducts 2 were etherified by methanol to afford the corresponding methyl ethers 3.This process provides a new method for the protection of the acid sensitive hydroxyl group in 2 under mild condition.
REACTION OF α-(1H-1, 2, 4-TRIAZOL-1-YL)ACETOPHENONE WITH PHENYL ISOTHIOCYANATE
Zheng Ming LI , Zhen Nian HUANG
1993, 4(9): 763-766
[Abstract](156) [FullText HTML] [PDF 80KB](3)
Abstract:
Reaction of α-(1H-1, 2, 4-triazol-1-yl) acetophenone with phenyl isothiocyanate in the presence of a base and subsequent alkylation leads to the ketene S, N-acetal (2), (4), (7), (8);thiazolidone (3), thiazolidine (5) and 1, 3-thiazine (6).
SYNTHESIS OF NEW CYCLIC PHOSPHATES OF 3-HYDROXYISOXAZOLE AND THEIR DIASTEREOMERS
Rui Lian SHAO , Min Hua YANG , Cheng Xin ZHI
1993, 4(9): 767-768
[Abstract](156) [FullText HTML] [PDF 70KB](0)
Abstract:
Keeping in view the biological activities of 3-hydroxyisoxazole and cyclic phosphate derivatives, some compounds possessing these two moieties have been synthesized, the structural elucidation of these diastereomers was made depending on spectral analyses.The mechanism could be illustrated by the theories of trigonal bipyramide intermediate and pseudorotation.
SYNTHETIC STUDIES ON 9-HYDROXY-CEMBRENE-C
Ling LI , Wei Dong LI , Yu Lin LI
1993, 4(9): 769-770
[Abstract](162) [FullText HTML] [PDF 70KB](0)
Abstract:
A dicarbonyl precursor of 9-hydroxy-cembrene-C, 8-tetrahydropyranoxy-3, 7, 11, 15-tetramethyl-14-oxo-2E, 6E, 10E-hexdecatrienal, was prepared from farnesyl acetate via four steps.
CHEMISTRY OF 1, 2, 4-TRIAZINES XIX
Mei HAN , Xu Ling SHI , Zhen Jun YANG , Meng Shen CAI , lie Ming CHENG
1993, 4(9): 771-774
[Abstract](150) [FullText HTML] [PDF 107KB](0)
Abstract:
3-Methylthio-5-hydroxy-1, 2, 4-triazine (1c) reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1, 2, 4-triazin-6-yl pyridinium betaine (4) in anhydrous pyridine.But when NaOH/H2O/CH3COCH3 or NaOH/CH3OH were used as reactant and solvent, 3-methylthio-4-substituted benzenesulfonyl-5-oxo-6-hydroxy-1, 4, 5, 6-tetrahydro-1, 2, 4-triazine (6) or 1-tosyl-3-methylthio-5-oxo-6-methyloxy-1, 4, 5, 6-tetrahydro-1, 2, 4-triazine (7) was obtained respectively.The above reactions show anomalous properties of nucleophilic attack on 6-carbon in 1, 2, 4-triazine ring.
ESTER EXCHANGE OF DIPP-HIS WITH ALCOHOLS
Yao Wu Sha , Bo Tan , Yu Fen Zhao , Li Hua Yang , Yu Ping Feng
1993, 4(9): 775-778
[Abstract](161) [FullText HTML] [PDF 109KB](0)
Abstract:
Here reported the ester exchange of DIPP-His with primary alcohols and found that the rate of this reaction was increased as the increment of the carbon chain of alcohols used.
A STUDY OF PACKING STRUCTURE OF POLY (P-PHENYLENE BENZOBISTHIAZOLE) BY MOLECULAR SIMULATION
Yue LIU , Xiao Zhen YANG
1993, 4(9): 779-782
[Abstract](189) [FullText HTML] [PDF 173KB](0)
Abstract:
Molecular simulation technique was used in an examination of the possibilities of chain packing in the crystalline state for poly (p-phenylene benzobisthiazole).It has been found that one reason of hardly forming very ordered crystal of the polymer is the existence of so many stable positions of interchain interaction along chain axis.
STRUCTURE OF NERVOSIN D ISOLATED FROM ISODOM NERVOSUS
Mei Juan XU , Xin En HUANG , Pei Yuan CHENG , Jin XIANG , Mai TANG
1993, 4(9): 783-784
[Abstract](150) [FullText HTML] [PDF 96KB](0)
Abstract:
On the basis of spectral analysis combined with preparation of derivatives, nervosin D was identified as ent-1α, 6β, 7β, 11α, 15β-pentahydro-xy-7α, 20-epoxykaur-16-ene.
TWO NEW IRIDOID GLYCOSIDES FROM PEDICULARIS PLICATA
Zhong Jian JIA , Jian Jun GAO , Zi Min LIU
1993, 4(9): 785-786
[Abstract](152) [FullText HTML] [PDF 70KB](0)
Abstract:
Two new iridoid glycosides, plicatoside A and plicatoside B, were isolated from whole plants of Pedicularis plicata.Their structures were identified as 2'-O-β-D-glucosyl ixoroside and 4'-O-β-D-xylosyl mussaenoside by means of chemical evidence and spectral data.
ISOLATION AND STRUCTURE DETERMINATION OF XF-1, A NEW ANTHRACYCLINE ANTIBIOTIC
Xu Guang YAN , Jian Bo WU , Shao Zhao WANG
1993, 4(9): 787-790
[Abstract](153) [FullText HTML] [PDF 117KB](0)
Abstract:
A new Mutactimycin group antibiotic (XF-1) was isolated from the mycelium of Streptomyces sp.80-115 and its structure has been determined on the basis of its spectroscopical and chemical properties.XF-1 showed active against some Gram positive bacteria.
STUDIES ON FLUORESCENCE ENHANCING EFFECT AND ALKALINE DEGRADATION MECHANISM OF DOXYCYCLINE AND METHACYCLINE
Yi Bing ZHAO , Wen Bao CHANG , Yun Xiang CI
1993, 4(9): 791-792
[Abstract](159) [FullText HTML] [PDF 92KB](3)
Abstract:
Degradation reaction of doxycycline or methacycline was carried out in KOH solution and intense fluorescence was obtained.A degradation mechanism of doxycycline or methacycline was suggested.
ENUMERATION OF ISOMERS OF SUBSTITUTED CROWN ETHERS
Shi Jun YU , Jian Ji WANG
1993, 4(9): 793-794
[Abstract](150) [FullText HTML] [PDF 83KB](0)
Abstract:
The graphtheory method is used to enumerate the numbers of constitutions, configurations, chiral and achiral configurations of substituted crown ethers.The numerical results are tabulated.
THE THEORETICAL STUDY ON INTERSECTION POINT RULE FOR HOMOLOGUES IN GAS CHROMATOGRAPHY
Fu An WANG , Qing Lai TIAN , Ying Chen GUO , Ting Zhu CAO
1993, 4(9): 795-796
[Abstract](155) [FullText HTML] [PDF 80KB](0)
Abstract:
The intersection point rule for homologues in gas chromatography was discovered many years ago[1], now more and more application and development are occurring in recent years[2-6], but there are few systemic theoretical studies.In this paper, based on the basic equation of retention values in gas chromatography, we prove the intersection point rule of homologues from mathematics, study the factors affecting intersection point position, give the physical meaning of intersection point, and explain the experimental rules in references.
GAS-PHASE ION-MOLECULE REACTIONS OF BUCKMINSTERFULLERENE (C60) WITH Si (CH3)n CL4-n(n=2, 3) IN MASS SPECTROMETER
Xing Hua GUO , Zi Yang LIU , Shu Ying LIU
1993, 4(9): 797-800
[Abstract](163) [FullText HTML] [PDF 114KB](0)
Abstract:
Reactions of C60 with Si(CH3)nCl4-n (n=2, 3) in the ion source of the mass spectrometer have been studied.The corresponding adduct ions[C60Si(CH3)mCl3-m]+(m=1, 2, 3), [C60SiCl]+ and [C60CH3]+ were observed and their possible structures were discussed.The results indicated that C60 is very reactive to electrophiles in the gas phase.
MATHEMATICAL MODEL FOR THERMOKINETICS OF IRREVERSIBLE CONSECUTIVE FIRST ORDER REACTIONS
Jing Song LIU , Xian Cheng ZENG , Yu DENG , An Min TIAN
1993, 4(9): 801-804
[Abstract](156) [FullText HTML] [PDF 111KB](0)
Abstract:
The mathematical model for the thermokinetics of irreversible consecutive first order reactions has been suggested, which was used for the calculation of rate constants and molar enthalpies of the two consecutive steps.And its validity has been verified by the experimental results.
A THEORETICAL STUDY OF THE THERMODYNAMIC AND KINETIC PROPERTIES FOR THE REACTION OF FORMYL CYANIDE DECOMPOSITION
Fens Ling LIU , Shi Guang NING , Bao Ji CHEN , Ming Li SHI
1993, 4(9): 805-808
[Abstract](155) [FullText HTML] [PDF 108KB](1)
Abstract:
We compute the thermodynamic and the kinetic properties for the reaction:HCOCN→HCH+CO using the statistical theory and the transition-state theory.The equilibrium constants and the rate coefficients of this reaction are also reported here, and the half lives of formyl cyanide at different temperatures are first estimated in this work.
TERNARY COMPLEXES OF Cu (ATP) AND HETEROAROMATIC N BASE-ISOQUINOLINE AND BENZIMIDAZOLE:STABILITY CONSTANT AND STACKING EFFECT
Fu Hai WU , Bin SONG , Liang Nian JI
1993, 4(9): 809-812
[Abstract](150) [FullText HTML] [PDF 138KB](0)
Abstract:
The stability constants of the binary complexes of Cu2+ with isoquinoline and benzimidazole as well as the ternary complexes of Cu(ATP) with the same ligands have been measured in aqueous solution spectrophotometrically and a strong stacking interaction between the heteroaromatic ring of the ligands and the purine moiety of ATP has been found.The fact of this stacking interaction is much stronger than that in the systems of Cu(ATP) with pyridine and imidazole shows that the stacking interaction increases with the size of the heteroaromatic ring of the ligands.
A PHOTOELECTROCHEMICAL INVESTIGATION OF LATTICE-MATCHED SQW GaAs/AlxGa1-xAs ELECTRODE
Yao LIU , Yuan LIN , Xue Ping LI , Xu Rui XIAO , Chun Hui YAN , Yi Ping ZENG , Dian Zhao SUN , Hai Qun ZHENG , Hong Xi GUO
1993, 4(9): 813-814
[Abstract](156) [FullText HTML] [PDF 90KB](0)
Abstract:
Single quantum wells (SQWs) of GaAs/AlxGa1-xAs have been investigated as photoelectrodes in photoelectrochemical cells.Structured photocurrent spectra for well widths of 50Å and 100Å SQWs were obtained in nonaqueous solution.The dependence of structured photocurrent spectra on electrode potential were exhibited.The quantum yield was higher in SQW with 100Å well compared to 50Å well.
IMPS STUDIES OF SEMICONDUCTOR CdSe THIN FILM ELECTRODE
Yuan LIN , Xu Rui XIAO
1993, 4(9): 815-816
[Abstract](158) [FullText HTML] [PDF 107KB](0)
Abstract:
The kinetics of interracial processes of CdSe thin film electrode before and after surface modification of 1, 1'-di linolene ferrocenyl L-B films have been studied in K4Fe(CN)6 solution by Intensity Modulated Photocurrent Spectroscopy (IMPS).Potential dependence of surface state relaxation time (Ts), steady state photocurrent (Is), collection coefficient of minority carriers (Go), rate constant of photocorrosion (Kcr), and density of surface state (Nss) were determined in terms of frequency response analysis of IMPS plots.
FURTHER EVIDENCE FOR FA CENTERS IN BaFCL:Eu2+ CRYSTAL
Wei CHEN , Mian Zeng SU
1993, 4(9): 817-820
[Abstract](161) [FullText HTML] [PDF 118KB](0)
Abstract:
The formation of color centers in BaFCl:Eu2+ crystal is studied in more detail and further evidence for FA centers in BaFCl:Eu2+ is reported.The creation of color centers in BaFCl:Eu2+ may be devided into three stages.Under long time X-irradiation beyond stage 1, the concentration of FA centers depends linearly on the nth (n=1, 2 or 3) power of F center concentration.While under short time X-irradiation within stage 1, the concentration dependence of FA centers on F center is complex.Simple centers are easier to create than complex centers.Possible mechanisms for color centers formation in BaFCl:Eu2+ are also proposed and discussed.
THE ELECTROCATALYTIC ACTIVITY OF NiC204 FOR THE OXYGEN EVOLUTION REACTION
Peng Li CHENG , Jian Min ZHANG , Qiu Zhi SHI , Chang Chun YANG
1993, 4(9): 821-824
[Abstract](157) [FullText HTML] [PDF 170KB](0)
Abstract:
A spinel oxide NiCo204 prepared by thermal decomposition is of very high activity for the oxygen evolution reaction (OER) in alkaline solution.The oxygen evolution overpotential on NiCo204 is 0.252-0.262V in 10 M NaOH solution at 343K and current density 100 mAcm-2.
THE PROCESS OF THE EMULSIFIER-FREE POLYMERIZATION IN THE PRESENCE OF BARIUM SULFATE POWDER
Li CHEN , Jing LIN , Min LIN , Hai Shui HUNG
1993, 4(9): 825-826
[Abstract](154) [FullText HTML] [PDF 81KB](0)
Abstract:
The process of emulsifier-free copolymerization of the Styrene-Butyl Acrylate-K2S2O8-water in the presence of Barium Sulfate (BS) powder was investigated under varied conditions within the range of BS powder quantity, initiator concentration and reaction temperature.Experimental results showed that the rate of polymerization is proportional to 0.3-power of the BS quantity and 1.3-power of the initiator concentration.There is a linear relationship of 2/3-power for the conversion and time.A process for the polymerization is propose to explain the experimental results.
CAPILLARY ELECTROPHORETIC SEPARATION OF GANGLIOSIDES USING CYCLODEXTRIN AS BUFFER ADDITIVE
Zhao Lou YU , Li Wen CHANG , Tian Sheng SU
1993, 4(9): 827-828
[Abstract](148) [FullText HTML] [PDF 81KB](0)
Abstract:
A new method for the rapid separation of gangliosides (GLS) by capillary electrophoresis (CE) is described which is based on the use of β—cyclodextrin (β—CD) as buffer additive.The effects of β—CD concentration, pH, electrolyte composition were discussed.Under optimum conditions, the complete separation of a mixture of GM1, GD1a, GD1b and GT1b was obtained within 5 min.
IN-SITU TIME-RESOLVED RAMAN SPECTROSCOPIC STUDIES OF SILVER ELECTRODE IN NaSCN SOLUTION
Wu Hu LI , Zhong Qun TIAN , Jing Song GAO , Qi XUE
1993, 4(9): 829-830
[Abstract](139) [FullText HTML] [PDF 91KB](0)
Abstract:
In-situ time-resolved Raman spectroscopy (TRRS) has been applied on studies of electrochemical adsorption of thiocyanate at silver electrode during potential cycles and potential step.It is shown that some dynamic information about the adsorption and desorption processes can be obtained.
THE MECHANISM OF SURFACE METALLIZATION OF POLYVINYL ALCOHOL COMPLEX METAL CHELATE FILMS
Ding Sheng YU , Shi Zhi CHEN , Shu Ke JIAO
1993, 4(9): 831-832
[Abstract](126) [FullText HTML] [PDF 245KB](0)
Abstract:
A novel method for preparing metalllzed film has been studied.The reduction process and properties of the poly (vinyl alcohol) (PVA) were probed by several analytic means.According to the etudies, a mechanism for the polymer surface reduction metallization was proposed and proved.
TEMPERATURE DEPENDENCE OF AIR SEPARATION OF LIQUID CRYSTALLINE TRIHEPTYL CELLULOSE/ETHYL CELLULOSE MEMBRANES
Xin Gul LI , Mei Rong HUANG , Gang LIN
1993, 4(9): 833-836
[Abstract](128) [FullText HTML] [PDF 185KB](0)
Abstract:
Triheptyl cellulose/ethyl cellulose (3/97) binary blend membranes were prepared from tetrahydrofuran, chloroform and dichloromethane solutions and their air separation capabitities were studied at different temperatures.With increasing temperature from 25 to 85℃, the flux QOEA of O2-enriched air (OEA), O2 permselectivity and the O2 concentration Yo2 in the OEA all increase.The membranes show a unique trend in their Yo2~QOEA relationship, that is, the air separation capability increases simultaneously with the OEA permeation capability.The magnitudes of QOEA and Yo2 for 17μm-thick membrane after the testing time of 36hours at 70℃ are 5×10cm3 (STP)/s·cm-2 and 37.6%, respectively.The air separation capability depends slightly on membrane forming solvents.
SPECTROSCOPIC STUDIES ON A HETEROMETALLOBINUCLEAR COMPLEX IN WHICH Ru (BPY)32+ WAS COVALENTLY ATTACHED TO Ni (CYCLAM)2+
Xian He BU , Yu LIU , Yun Ti CHEN , M.SHIONOYA , E.KIMURA
1993, 4(9): 837-840
[Abstract](129) [FullText HTML] [PDF 146KB](0)
Abstract:
The spectroscopic properties for a recently synthesized hetero-metallobinuclear complex Ru(bpy)2 (bpy-cyclam-Ni)4+ (3) and its related complexes 1 and 2 were investigated by UV-vis and emission spectral methods.A drastic quenching offluorescence from the Ru(bpy)32+ subunit by the covalently attached quencher subunit Ni(cyclam)2+ was observed for complex 3, and the mechanism was discussed.
A SIMPLE ACCESS TO UNSOLVATED MONOMERIC COMPLEXES OF EARLY LANTHANIDE IODIDES (CH3OCH2CH2C5H4)2LnI (Ln=La, Nd) VIA THE REACTION OF[(CH3OCH2CH2C5H4)2LnCl]2 WITH NaI AND X-RAY CRYSTAL STRUCTURE OF THE LANTHANUM COMPLEX
Chang Tao QIAN , Bing Wang , Xiao Fan ZHENG , Dao Li DENG , Jie SUN
1993, 4(9): 841-844
[Abstract](132) [FullText HTML] [PDF 116KB](0)
Abstract:
(CH3OCH2CH2C5H4)2LnI (Ln=La, Nd) complexes have beensynthesized by the reaction between NaI and [(CH3OCH2CH2C5H4)2LnCl]2 in THF; A single crystal X-ray study has shown that the lanthanum complex is an unsolvated monomer with lanthanum (Ⅲ) in a trigonal bipyramidal coordination geometry if the cyclopentadienyl ring is regarded as occupying a single polyhedral vertex.
THE SYNTHESIS OF ZSM-35 WITH A NEW KIND OF TEMPLATING AGENT
Tian You SONG , Jia Ning XU , Yao Cai TONG , Ru Ren XU
1993, 4(9): 845-846
[Abstract](145) [FullText HTML] [PDF 84KB](0)
Abstract:
The present paper covers the synthesis of ZSM-35 molecular sieve with 1, 6-hexanediamine as templating agent, the influence of the synthesis conditions, and a discussion concerning the crystal structures of the products.
Address:Zhongguancun North First Street 2,100190 Beijing, PR China Tel: +86-010-82449177-888
Powered By info@rhhz.net