Chemical Research in Chinese Universities

Hydrothermal Synthesis and Structural Characterization of a Novel Mixed-Valence Sodium Vanadium(Ⅳ,Ⅴ) Phosphate Na_3.6H_1.4P₂V₅O₁₈·11H₂O

PANG Guang-sheng, FENG Shou-hua, XU Ru-ren

1998, 14(4): 351-355.

Abstract ( )

PDF (1193KB) ( )

Related Articles | Metrics

A novel mixed-valance vanadium phosphate Na_3.6H_1.4P₂V₅O₁₈·11H₂O was synthesized by a hydrothermal method and its structure was characterized by X-ray diffraction, infrared spectroscopy, differential thermal analysis, and thermogravimetric analysis. Na_3.6H_1.4P₂V₅O₁₈·11H₂O crystallizes in the cubic system with the cell parameter a =1.601(8) nm. The ratio of V( Ⅳ)/ V(Ⅴ) in the compound is 3.55.

Synthesis,Characterization and Catalytic Activity of ZnAl Anionic Clay Pillared by α-Na₆[GaW₁₁O₃₉Fe(H₂O)]·18H₂O

YU Xin-wu, ZHANG Shu-yun, HUANG Ru-dan, ZHANG Su-xia, WANG En-bo

1998, 14(4): 356-358.

Abstract ( )

PDF (175KB) ( )

Related Articles | Metrics

ZnAl-NO₃ type of anionic clay pillared by GaW₁₁ Fe was successfully synthesized and charac-terized by XRD,IR and DTA.Its catalytic activity for the for mation reaction of DOP was tested.

Stability Constants and Fluorescence of Terbium(Ⅲ) Complexes with Polyaminopolycarboxylates in Aqueous Solution

GONG Meng-lian, WU Wei-ning, SHI Hua-hong, LEI Heng-yi, MENG Jian-xin, YANG Yan-sheng

1998, 14(4): 359-364.

Abstract ( )

PDF (287KB) ( )

Related Articles | Metrics

Five polyaminopolycarboxylic acids(EDT A and DTPA derivatives),DTPA·pAS,DT PA·2pA S,D T P A·pA B,EDT A·pA S and ED T A·pAB,w her e pA S and pA B repr esent p-aminosal-icylate and p-amino benzoate groups,r espectively,were synthesized,and the stability constants of Tb³⁺complexes with these lig ands were deter mined,for the first time,by means of pH potentio-metrictitration.The complex ationrates of Tb(Ⅲ)with these ligands were found to be very slow,so batch technique was employed in the titration.The stepwise protonation constants of the ligands and the stability constants of their Tb³⁺ complexes were calculated with the progr am BEST.It was shownthatintr oducing p-aminosalicylate or p-amino benzoate groups into EDT A or DTPA leads to the decrease in acidity.The species distributions in the complex solutions at various pH accorded with the results of fluorescence measurements.A replacement of EDT A with DTPA·2pAS in EDTA-Tb complex solutionled to the enhancement in Tb³⁺ sensitized luminescence.The effects of the ligands'structure on the stability and fluo rescence of the complexes were discussed.

Studies on Phosphate Effect of Cytosine and Its Novel Photoproduct

LIN Feng, WANG Wen-qing, WU Ji-lan

1998, 14(4): 365-369.

Abstract ( )

PDF (266KB) ( )

Related Articles | Metrics

Under the irradiation of a middle pressure mercury lamp(MPML), we found that the photo lyses of nucleobases, nucleosides and nucleotides were strongly enhanced by phosphates (termed phosphate effect). In order to explain this phenomenon, the photolytic systems of cytosine in phosphate solutions were selected and studied. Experimental results indicated that the UV irradiation (190-220 nm) in the emission spectra of MPML is responsible for the phosphate effect. Phosphates absorbing the UV (190-220 nm) energy are converted to phosphate radical anions, which react with cytosine, leading to a novel photoproduct with phosphate group (C₄H₆N₃O₅P). It has been isolated, purified and characterized by means of elementary analysis, UV, IR, EI MS, 1H NMR, ¹³ C NMR and ³¹ P NMR. The phosphate effect and its formation mechanism have been discussed.

Determination of Cd,Pb and Sr by Microwave Plasma Torch Atomic Emision Spectrometry Using an Electrothermal Vaporization Sample Introduction System

ZHAO Li-wei, ZHANG Han-qi, CAO Yan-bo, YANG Wen-jun, JIN Qun, JIN Qin-han, FU Yao

1998, 14(4): 370-374.

Abstract ( )

PDF (229KB) ( )

Related Articles | Metrics

A method for the determination of Cd,Pb and Sr by microwave plasma torch(MPT)atomic emission spectrometry(AES)was developed.The samples were introduced into the MPT with an electrothermal vaporization(ETV)device.The effects of some experimental conditions on the determination of Cd,Pb and Sr were examined.The effects of easilyionized elements on the emission intensity of Cd,Pb and Sr were studied in detail.The detection limits for Cd,Pb and Sr are 2.4,4.0 and 1.3 ng/mL,respectively.

Synthesis and Crystal Structure of 10-Phenyl-1,7-dithia-4-oxa-10-aza-12-crown-4

NIU Chang-rong, JIANG Hua, WU Cheng-tai, LUO Bao-sheng

1998, 14(4): 375-378.

Abstract ( )

PDF (295KB) ( )

Related Articles | Metrics

The crystal structure of the title compound C₁₄H₂₁ONS₂ was determined by means of X-ray diffraction method.Its crystallog raphic data are as follows:M_r=283.46,it is a monoclinic crystal system,the space group P2₁/n,a=1.273 7(3)nm,b=1.510 9(5)nm,c=0.798 0(6)nm,=107.17(3)°,V=1.467 4 nm³,Z=4,D_c=1.283 g·cm^-3,(MoK)=3.370 cm^-1,F(000)=608,R₁=0.079,R_w=0.076 for 1.689 observed reflections with I≥6(I).Both the phenyl and hetero cyclic rings in the title compound are distorted to form a conjugate system.

Synthesis and Photophysics of a Flavone Derivative with Lariat Ether as a Fluoroionophore

WANG Peng-fei, WU Shi-kang

1998, 14(4): 379-386.

Abstract ( )

PDF (407KB) ( )

Related Articles | Metrics

A new kind of fluoroionophore——a flavone derivative linked to 12-crown-4 was synthesized and char acterized.The spectroscopy and photo physical behavior of the fluor oionophore for its complexation with different cations were investigated.The complexation causes a significant change of spectro scopy and photophysical properties and is attributable to the enhancement of the cation-induced intramo lecular charge transfer via directinter action of the cation bound to the crown and the carbonyl group of flavone.Based on the determination of the stability constant,the selectivit y for Ca²⁺ was found in the fluoroiono phore,which was totally different from the parent crown——12-crown-4.That could tentatively account for the high selectivity.It might be valuable for designing the new fluor oionophore linked crown.

Crystal Structure of the Addition Compound of N,N'-Bi(2-pyridylmethyl)-Oxamide and the Complex of Copper with 1,10-Phenanthroline

LIU Bin, WANG Hong-mei, LIAO Dai-zheng, YAN Shi-ping, JIANG Zong-hui, WANG Geng-lin, HUANG Xiao-ying

1998, 14(4): 387-390.

Abstract ( )

PDF (230KB) ( )

Related Articles | Metrics

The structure of addition compound Cu(phen)₃(PMoxdH₂)(ClO₄)₂ was established by means of X-ray crystallo graphy,where PMoxdH₂ is N,N'-Bi(2-pyridyl-methyl)-oxamide,in which six nitrogen atoms of the three 1,10,-phen-anthro line bind to the copperion and the oxygen atom of PMoxdH₂ is uncoo rdinated.

Electron Spin Resonance Spectra of Some Free Radical in Pure C₆₀ and Mixture of C₆₀/C₇₀

WANG Yue, ZHANG Ping, YANG Hai-bin, Zheng-Ying-guang, ZOU Guang-tian

1998, 14(4): 391-394.

Abstract ( )

PDF (191KB) ( )

Related Articles | Metrics

The character of some free radical in pure C₆₀ and a mixture of C₆₀ and C₇₀ was studied by means of ESR spectroscopy.The experiment results show that the ESR signals of the free ridical in C₆₀ or the mixture of C₆₀ and C₇₀ are dependent on oxygen and the ratio between C₆₀ and C₇₀.The radical in pure C₆₀ and the mixture of C₆₀ and C₇₀ possess the characteristic of carbon-centered radicals.

Structure and Orientation of 1-(Hydroxyl)-5-(dodecyloxy)-naphthalene LB Films by Polarized Fluorescence Spectroscopy

LI Xiao-ling, ZHAO Bing, WU Yu-qing, XU Wei-qing, LI Guo-wen, WU Ying, BAI Fang, CUI Shu-wen

1998, 14(4): 395-398.

Abstract ( )

PDF (249KB) ( )

Related Articles | Metrics

A new single-chain amphiphile 1-hydroxyl-5-dodecyloxy-naphthalene can be deposited onto substr ates to form LB films by means of the L ang muir-Blodgett technique with pure ater as the subphase.The steady-state fluorescence spectra of the LB films were recorded.The dependence of the relative content of the naphthalene excimers in the films uponag gregation state indicates that the excimer for mation is promoted by increasing the close packing density of the molecules.The molecular orientation in the LB films was studied by fluor escence polarization technique,and the results revealed that the naphthalene chromophores or iented perpendicularly to the layer plane.

A Study of Fluorescence System of Eu-Chlorotetracycline-Benzoylacetone-CTMAB Multibasic Complex

WU Xia, YANG Jing-he, ZHANG Gui-ling, LI Yong-shan, DING Yuan-ju

1998, 14(4): 399-403.

Abstract ( )

PDF (240KB) ( )

Related Articles | Metrics

A fluorescence Eu-chlorotetracycline-benzoylacetone-CT MAB system was studied.It was found that chlorotetracy cline formed a complex with Eu(Ⅲ)at pH 7.8—8.8 and then emitted the characteristic fluor escence of Eu(Ⅲ).Benzoy lacetone and CTMAB can greatlyenhance the fluorescence intensity of the system.The experiments indicated that under the optimum conditions there was a linear relationship between the fluorescence intensity and chlorotetr acycline concentr ation in the range of 1.8×10^-8—2.0×10^-5 mo \l/L.The detection limit was 2.3×10^-9 mol/L.Inaddition,the luminescence mechanism of the complex system is discussed.

4-Selena-7-thiaoctyl Polystyrene-supported Platinum Complex as Hydrosilylation Catalyst

MENG Ling-zhi, KE Ai-qing, CHEN Yuan-yin

1998, 14(4): 404-407.

Abstract ( )

PDF (241KB) ( )

Related Articles | Metrics

Polystyrene-bound Se,S mixed bidentate ligand and its platinum complex were separately prepared from the condensation reaction of swelled macroporous chloromet hylated polystyrene and-methylthio ethyl-'hydroxyethy l selenoet her in the presence of NaHin dioxane,and the reaction of the lig and with potassium chloroplatinite in acetone undernitro genatmosphere.The complex exhibited a high catalytic activity in the hydrosilylation of olefins,the turnover number was 44000 for the hydrosilylation of decene at 120℃ inonerun.

Studies of Permeabilities of Metallic Ions Through Crosslinked Chitosan Membranes

FANG Yue-e, LU Xiao-bing, WANG Huan-ting, CHENG Qing, CHEN Bo-jun, CHEN Guo-jun, WANG Yong-jie, WANG Shao-gen

1998, 14(4): 408-413.

Abstract ( )

PDF (348KB) ( )

Related Articles | Metrics

Chitosan and its crosslinked membranes were prepared with glutaraldehyde(GA)as crosslinking agent with the aid of solvent-casting technique and were characterized by means of infrared,X-ray diffraction,and contact angle testing methds.These membranes have a higher permeability to K⁺,Na⁺,Mg²⁺and Ca²⁺who seper meability order is as follows:K⁺>Na⁺>Mg²⁺>Ca²⁺.The DSC ther mograms of the crosslinked membranes confirmed the existence of two types of water.The amount of free water in the swollen membranes increased with increasing the crosslinking density.The effect of crosslinking reaction on permeation rate was explained by presuming to permeate through the free water region in the swollen membrane.

Hydrophobic Pocket Modification and Humanized Catalytic Antibodies with Glutathione Peroxidase Activity(Ⅰ)——Preparation and Characterization of Haptenes and Conjugates

WANG Lin, MA Xue-yan, DING Lan, ZHAO Da-qing, NI Jia-zuan, FU Ping-ping, LI Xiao-ping, JIN Xiang-jun

1998, 14(4): 414-419.

Abstract ( )

PDF (436KB) ( )

Related Articles | Metrics

The thiol group of glutathione(GSH)was protected by 2,4-dinitrochlorobenzene(DNCB),the product S-substituted dinitrophenyl GSH(GSH-S-DNP)was alcoholized to obta in haptenes 4 and 5 respectively.As haptenes,the two GSHderivatives were characterized by means of 1 HNMR,MALDI-T OF-MS and IR,followed by individually coupling with bovine serumalbumin(BSA)viag lutar aldehyde.BSA-Hp4 and BSA-Hp5 were purified by Sephadex G-25 gel filtration chromatography.For each conjugate,the average haptene-BSA ratio was 12:1.The electro phoresis analysis showed that the average molecular weight of each conjugate was 76 500.The CD spectrum indicated that the conjugates had more-helix content than BSA did.

A Simple Method Designed for the Separation of Biotinylated Ligate from Free Biotin

LI Tian-yu, ZHOU Chang-cheng, FANG Rui, QI Jie, ZHOU Hui, LI Wei

1998, 14(4): 420-422.

Abstract ( )

PDF (190KB) ( )

Related Articles | Metrics

Considering the chemical characteristics of the biotinylate reagent,we designed a method for the separation of biotinylatedlig ate from residual biot inylate reagent with equal efficiency to ultr afiltration.This metho disespecially fit for the separation of biotinylating small molecules.

The Ozonization of Stigmast-4,22-dien-3,6-dione

CUI Jian-guo, ZENG Long-mei, SU Jing-yu, HE Yan-hong

1998, 14(4): 423-425.

Abstract ( )

PDF (156KB) ( )

Related Articles | Metrics

A New Furanolactam from the Chinese Sponge Phacellis Fusca

ZENG Long-mei, ZHU Ye, YAN Su-jun, SU Jing-yu

1998, 14(4): 426-427.

Abstract ( )

PDF (191KB) ( )

Related Articles | Metrics