中国化学快报

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DEPROTECTION OF ACETALS AND KETALS WITH CpTiCl₃-KI

Shao Zu WU, Ya Lan ZHANG, Tian Hui REN, Ning CHEN

中国化学快报. 1991, 2(12): 907-910.

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When the mixture of CpTiCl₃-KI is used, many acetals and ketals, which are difficuitly deprotected with CpTiCl₃ alone, can be easily converted to the corresponding carbonyl compounds in high yield at 30℃ in Et₂O.

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SYNTHESIS OF ASYMMETRIC ETHERS CLEAVAGE OF ACYCLIC ACETALS WITH ZrCl₄-LiAlH₄

Shao Zu WU, Yu Lan ZHANG, Tian Hui REN

中国化学快报. 1991, 2(12): 911-912.

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In this paper, we investigated the selective cleavage of acyclic acetals with the reagent system, ZrCl₄-LiAlH₄. The results indicate that this system is very useful for the cleavage of acyclic acetals to the corresponding asymmetric ethers.

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TBE EFFIGIENGIES OF THREE INITIATORS OF Fe²⁺-H₂O₂, K₂S₂O₈, KMnO₄ AND TBE KINETIC EQUATION IN THE GRAFTING OF AGRYLAMIDE ONTO STARCH

Guang Zhong YAHG, Wen Hua GUO, Quan Sheng LI, Shao Jie LU, Xi Hai CUI, Shu Cheng MO, Yin Hun SHI

中国化学快报. 1991, 2(12): 913-916.

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A comparative study is made on the efficiencies of three initiators ofFe²⁺-H₂O₂, K₂S₂O₈, KMnO₄ in the grafting of acrylamide onto starch. Of the three initiators the best one is KMnO₄. Moreover, the kinetic equation is also studied.

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SYNTHESIS AND PROPERTIES OF 1-(2-IMIDAZOLYLAO)2-NAPHTHOL-4-SULFONIC ACID

Fu You PAN, Sun Wei ZHANG

中国化学快报. 1991, 2(12): 917-918.

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Synthesis of 1-(2-imidazolylazo)-2-naphthol-4-sulfonic acid is described including its physical and chemical properties and spectroscopic data. The reagent reacts with various transition metal ions to form water-soluble and colored chelates which can be decomposed by EDTA exoept cobalt chelate. Present method has good selectivity.

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STUDIES ON CYCLOPENT-2-ENONE:(Ⅳ)PREPARATION OF UNSATURATED δ-LACTONES FROM THE ALDOLS OF CYCLOPRNT-2-ENONE

Xiao An ZHANG, M. M. Campbell, D. W. Brown, A. P. Taylor

中国化学快报. 1991, 2(12): 919-920.

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A new route was developed for diastereoselective preparation of δ-(α-hydroxyalkyl)-αβ-unsaturated δ-lactones. A single diastereoisomer(14) of the lactone was obtained after oxidation and elimination of (12).

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PREPARATION AND PURIFICATION OF SCHIFF BASE AND PROTONATED SCHIFF BASE FROM 9-CIS-RETINAL

Long JIANG

中国化学快报. 1991, 2(12): 921-924.

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A modified method for preparation and purification of Schiff base and protonated Schiff base from 9-cis-retinal has been suggested. Reaction took place in chloroform phase and purification was conducted by using water to remove the excess solvent, base and acid

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NEW HETEROCYCLIC SYSTEM SYNTHESIS I REACTION OF DIHYDRO-1,5-BENZO-DIAZEPINES AND THIAZEPINES WITH (ETHOXYCARBONYL)CARBENES

Bao Yu MI, Sheng JIN

中国化学快报. 1991, 2(12): 925-926.

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Dihydro-1-benzoyl-1,5-benzodiazepines react with (ethoxycarbonyl)carbenes to give 4H-azirino-[1,2-a] [1,5]-benzodiazepines and unexpected new ring system 1H-pyrrolo-[1,2-a] [1,5]-benzodiazepines. Dihydro-1,5-benzothiazepines react with (ethoxycarbonyl)carbenes in cyclohexane to gire unexpected ring cleavage products ethyl (2E, 4E)-3-aryl-2-arylthiohexadienoates.

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Facile Resolution of Racemic 4-Phenyl-2-hydroxy Butyrate via Enzymatic Esterification and Transesterification

Jin wang Xu, Zu yi Li

中国化学快报. 1991, 2(12): 927-928.

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The optically active R-4-phenyl-2-hydroxy butyrates were prepared by esterification of the racemic acid or transesterification of the racemic ester catalyzed by lipase from Candida cyclindra (CCL) in organic media.

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STUDIES ON STEROIDAL PLANT GROWTH REGULATOR 24. STEREOCONTROLLED CONSTRUCTION OF THE SIDE CHAIN OF BRASSINOLIDE AND HOMOBRASSINOLIDE VIA A TANDEM VICINAL DIALKYLATION OF PYRANONE MOIETY

Wei Shan ZHOU, Li Qiang SUN, Xin Fu PAN

中国化学快报. 1991, 2(12): 929-932.

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A stereocontrolled construction of the side chain of brassinclide and homobrassinolide has been achieved via the tandem vicinal dialkylation of the pyranone moiety as a key step.

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MOLECULAR POLARIZATION INDUCTION IN CONCERTED MECHANISM OF ALKOXY MIGRATION

Guo Qiang CHEN

中国化学快报. 1991, 2(12): 933-934.

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The rearrangement of α-substituted phenyl-α, α'-dimethoxypropanones (R1) was recently proved to he an[1, 3] siqmatropic migration of methoxy group by study of LFER, solvent effect, crossover experiment, and by other means. The rearrangement catalysed by trace of totuenesulfonic acid gave a negligible value of the Hammett reaction constant. Further experimental results show that the electronic effect of substituent on the aromatic ring for the rearrangement in neutral medium is much greater (Table 1). We propose sigmatropic migration of alkoxy group be induced by molecular polarization.

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A NEW SESQUITERPENE FROM CELASTRUS ROSTHONIANUS

Yong Qiang TU

中国化学快报. 1991, 2(12): 935-936.

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A new sesquitcrpene was isolated from Celastrus rothornianus, its structure was clucidated mainly on the basis of spectral analysis.

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CHEMICAL TPANSFORMATION OF TRIPTOLIDE

De Quan Yu, Dong Ming ZHANG, Huai Bin WANG, Xiao Tian LIANG

中国化学快报. 1991, 2(12): 937-940.

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Triptolide(1) gave 2-9 under various conditions specified in the text.

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ULTRAVIOLET SPECTROPHOTOMETRY OF MULTI-COMPONENT MIXTURES USING ARTIFICIAL NEURAL NETWORKS

Xin Hua SONG, Jian WANG, Ru Qin YU

中国化学快报. 1991, 2(12): 941-944.

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Three-layer back-propagation neural networks were used for processing the information provided by the ultraviolet spectra of five-component mixtures, affecting the simultaneous determination of the components with satisfactory results.

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A STUDY ON VOLTAMMETRIC BEHAVIOR OF INDIGO CARMINE AND ITS MIXTURE WITH AMARANTH AT MERCURY FILM ELECTRODE ON SILVER SUBSTRATE

Shu Cheng MO, Jian Min NA, Jiu Li WANG, Guang Zhong YANG

中国化学快报. 1991, 2(12): 945-948.

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The voltammetric behavior of indigo carmine at mercury film electrode on a silver substrate (MFES) was studied in this paper. It was found that indigo carmine gave a sensitive reduction peak at a potential (Vp) of-0.11 V at pH 4.0 in aqueous solution. The MFES gave good reproducibility and life time. The peak currents (ip) depended lipearly on the concentrations of indigo carmine free 0 to 100 ng/ml.

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DIRECT DETERMINATION OF NEODYMIUM AND ERBIUM IN RARE EARTH MIXTURE BY DERIVATIVE SPECTROPHOTOMETRY

ai Xing WANG, Ping QI

中国化学快报. 1991, 2(12): 949-952.

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The absorption spectra of 4f electron transitions of the complexes of neodymium and erbium with 8-hydroxyquinoline-5-sulphonic acid in the presence of diethylamine and ethanol have been measured by normal and third-derivative spectrophotometry. Their molar absorptivities are 70.7 l.mol^-1.cm^-1 for Nd and 62.5 l.mol^-1.cm^-1 for Er. They are 7.6 times and 14.9 times greater than those of corresponding chlorides, respectively. Use of the third-derivative spectra both eliminates the interference of Ce(Ⅳ) and increases the sensitivity for Nd and Er. Beer,s Law was obeyed from 0-10 ug/ml of Nd and Er. The method has been applied to the determination of neodymium and erbium in rare earth mixtures.

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ANALYSIS OF ETHACRYNIC ACID IN URINE BY HPLC-FLUORESEENCE DETECTOR

Xiu Feng HE, Ya Wei LI, Lin LI, Yun Ping WANG, Tong Hui ZHOU

中国化学快报. 1991, 2(12): 953-956.

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A sensitive and selective method has been developed for the detection of free ethacrynic acid in human urine. Using 4-(bromomethyl)-7-methoxycoumarin, ethacrynic acid was transformed into a fluorescent derivative, and was analysed by HPLC-fluorescence detector. The detection limit is 0.1ug/ml urine. The method is suitable for screening ethacrynic acid in doping control and studying its metabolism.

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SYNTHESES AND SPECTROSCOPIC PROPERTIES OF LANTHANIDE COMPLEXES, Ln(acac)₃(Ph₃PO)₃

Shu Qin SU, Shi Yah YANG

中国化学快报. 1991, 2(12): 957-960.

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A series of new complexes of formula Ln (acac)₃ (Ph₃PO)₃ (where Ln³⁺=Nd³⁺, Sm³⁺, Eu³⁺, Tb³⁺, Ho³⁺) have been prepared and characterized. The coordination of two ligands with lanthanide ions are studied by IR spectra, ¹H, ¹³C, ³¹P-NMR and metal-ligand charge tranafer tranaition is also discussed via electronic adaorption and luminescence spectroscopy.

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THE CRYSTAL STRUCTURE OF RARE EARTH COMPLEX WITH AMINO ACIDS Ⅱ The Crystal Structure of Gtutamate Comptex of Erbium Perchtorate

Zeng Lin WANG, Ning Hai HU, Chun Li NIU, Kui Yue YANG, Jia Zan NI

中国化学快报. 1991, 2(12): 961-962.

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The crystat structure of {[Er₂(L-Glu)₂ (H₂O)₆] (ClO₄)₂·3H₂O)₂ has been studied by X-ray diffraction. The crystal is monoctinic with space group P2₁ and cell parameters a=19.987(3)Å, b=16.505(3)Å, c=11.040(2)Å, β=104.69(1)°, V=3538(1)Å³, Z=2, Dc=2.29 g. cm^-3, μ=53.2 cm^-1, F(000)=2384. The asymmetric unit contains two complex motecules and four centre ions. Each erbium (Ⅲ) is coordinated by five oxygen donors from four different glutamates and four oxygen donors from the aqua ligand to form a nine coordination potyhedron. The mean distances of Er-0 (carboxylate) and Er-Ow are 2.439Å and 2.416Å respectivety. The finat R and Rw are 0.043 and 0.058, respectivety.

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THE COKING PROPERTIES AND STATES OF AN INDUSTRIAL W-Ni USED CATALYST

Ji Gang LUO, Chen Lie LI, Ming Shi LI, Yan ZHO, Xi Hui LUO

中国化学快报. 1991, 2(12): 963-966.

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PASCA, ESR and Microreactor, have been used to study the states and properties of coking deposits on catalyst. The results indicate that the C exists as three types of states on catalyst surface. The first and second types of carbon are the main reason of the catalyst deactivation, but the third type has a promoting role in n-C₇ hydrocracking reaction. The S_s-C interacts strongly with catalyst, forming metal-carbon-support interaction (MCSI).

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OXIDATIVE COUPLING OF METHANE OVER Na₂CO₃ DOPED ZIRCONIUM DIORIDE

Yong Qiang GONG, Fan Cheng WANG, Chak Tong AU, Hui Lin WAN, Khi Rui TSAI

中国化学快报. 1991, 2(12): 967-970.

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Na₂CO₃/ZrO₂ catalyst shows a high activity of oxidative coupling of methane. It possesses stronger electron donor ability than that of ZrO₂ catalyst. The activation of methane is supposed to relate to the O₂^- or O₂^2-and O^- species.

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IPN's PVA AND ITS CELL GROWTH PROPERTY

Shen Guo WANG, Shu Qin LIU, Makoto KODAMA

中国化学快报. 1991, 2(12): 971-972.

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6 kinds of IPN's PVA were synthesized by using different monomers of HEMA, MAA and MMA. The effect of adding polysaccharide was also studied. The cell growth on them were determined and compared. The results showed that the cell growth property of the IPN's PVA with hydrophobic monomer of MMA is better, and it can be improved further by adding hyaluronic acid.

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APPLICATION OF SUPERCRITICAL TECHNIOUE IN PREPARATION OF ULTRAFINE OXIDE PARTICLE

Li Juan FENG, Song Ying CHEN, Shao Yi PENG

中国化学快报. 1991, 2(12): 973-974.

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Ultrafine particle (UFP)alumina has been prepared by supereritical fluid drying process of inorganic salt with organic solvent system, which is reported for the first time. UFP-alumina prepared from this system is featured by its hish specific surface area, large pore volume, small perticle size and low bulk density.

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A NEW REACTIVITY INDEX——PSEUDO ORBITAL INDEX

Fu Jiang DING, Liang Fu ZHANG, Guang Nian LI

中国化学快报. 1991, 2(12): 975-978.

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The concept of pseudo orbital has been proposed, which includes the interactions of all the orbitals and extends the applicable limit of Fukui's frontier orbitals. An example shows that the pseudo orbital reactivity indexes are probably able to explain more complicated phenomena in chemical reactions.

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SYNTHESIS OF DBA-VPI-5 AND ITS PHASE TRANSFORMATION

Wen Tong TIAN, Li Min WANG, Shi Lun QIU, Wen Qin PANG

中国化学快报. 1991, 2(12): 979-982.

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New synthetic condition in a wide temperature range from 110℃ to 190℃ was employed to crystallize DBA-VPI-5. The phase transformation of the samples prepared at different temperatures was measured by high-temperature x-ray diffraction technique.

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1991年, 第2卷, 第12期　刊出日期：1991-12-20

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1991年, 第2卷, 第12期 刊出日期：1991-12-20

1991年, 第2卷, 第12期　刊出日期：1991-12-20