Table of Content

24 April 2001, Volume 22 Issue 4

Previous Issue    Next Issue

Articles

Studies on Oxidation Reaction of C₆₀

LI Xu, CAI Rui-Fang, KONG Qing-Yu, ZHAO Li, LI Yu-Fen, YU Hong-Kun, HOU Jian, HOU Hui-Qi

2001, 22(4):  515-519. 

Asbtract ( )   PDF (509KB) ( )  

Related Articles | Metrics

Two oxidation products of the reaction of C₆₀ with O₃ in toluene or dichlorobenzene were obtained in dependence on the amount of ozone absorbed by the solution and the reaction time. The short time oxidized product is insoluble in common organic solvents and water, but the water soluble derivatives were obtained after hydrolysis under a basic condition. It's IRspectrum is similar with that of C₆₀ polyhydric derivatives. The extensive oxidation product of C₆₀ is water soluble without any further dispose. The structures of the two oxidized products were characterized by variable temperature FTIR, XPS, elementary analysis, TGAand TOF MS, ESI MS, FAB MStechnique. Both products are thermally unstable, H₂O, CO and CO₂ are eliminated during the increase of temperature.

Studies on the Synthesis and Characterization of Sandwich Type Polyoxometalate (Bu₄N)₇H₃[Ru₂O(H₂O)₂(γ-SiW₁₀ O₃₆)₂]

XU Jing-Yu, LI Pei, LIN Xin-Rong, LI Ming-Xing, JIN Song-Lin, XIE Gao-Yang, SUN Wen-Liang

2001, 22(4):  520-523. 

Asbtract ( )   PDF (211KB) ( )  

Related Articles | Metrics

A di-ruthenium cluster substituted polyoxometalates(Bu₄N)₇H₃[Ru₂O(H₂O)₂( γ-SiW₁₀ O₃₆ )₂] was synthesized by using γ-[SiW₁₀ O₃₆ ]^8- and K₄Ru₂OCl₁₀ as precursors. Several methods (including IR, UV, EPR, magnetic moment measurement, CVand ¹⁸³W NMR) were used to determine the purity and structure of the title compound. IR, UVdata confirmed the purity, the maintenance of the γ-type structure and the substitution of the di-ruthenium cluster; the data of UV, EPRand magnetic moment measurement ensured that the linear structure of K₄Ru₂OCl₁₀ is still kept; CVand ¹⁸³W NMRdata determined the C_2h symmetry sandwich structure of the title compound.

Synthesis of Single phase Cubic Ce_0.5Zr_0.5O₂ Solid Solution under High Pressure and High Temperature

XU Da-Peng, WANG Quan-Yong, ZHANG Gong-Mu, LI Li-Ping, SU Wen-Hui

2001, 22(4):  524-530. 

Asbtract ( )   PDF (777KB) ( )  

Related Articles | Metrics

Using nanoparticles of CeO₂ and ZrO₂ prepared by chemical precipition method as the starting materials, the single phase cubic Ce_0.5 Zr_0.5 O₂ solid solution has been synthesized under high pressure and high temperature for the first time. The structural characteristics and valence state of the single phase cubic Ce_0.5 Zr_0.5 O₂ solid solution were investigated by XRD, TG-DTA, Raman, XPSand EPRmeasurements. The XRDresults showed that the nanocrystalline mixtures of CeO₂-50% ZrO₂ can form a cubic Ce_1-x Zr_x O₂ solid solution above 1.67 GPa and above 1073 K, but the product is in a mixture state. The single phase cubic Ce_0.5 Zr_0.5 O₂ solid solution can be obtained only under the certain conditions of 3.1 GPa at 1073 K. The high pressure promotes the process of the solid state reaction and the temperature of forming CeO₂ ZrO₂ solid solution decreases under high pressure. The DTAcurve of the single phase cubic Ce_0.5 Zr_0.5 O₂ solid solution showed a broad exothermic peak between 403 Kand 742 K. But the XRD pattern and Raman spectra displayed that the structure of the solid solution had not been changed before and after annealing at 773 Kfor 1 h. It revealed that the cubic Ce_0.5 Zr_0.5 O₂ solid solution was stable in structure below 773 K. The EPRspectra recorded at room temperature gave an evidence of the presence of Ce ³⁺ and O^2- in CeO₂ nanoparticles. However, the signals of Ce ³⁺ and O^2- have not been detected in Ce_0.5 Zr_0.5 O₂ solid solution. An unknown signal( g=1.990) has been observed in cubic Ce_0.5-Zr_0.5 O₂ solid solution which has not been changed after annealing at 773 K for 1 h, exhibiting that there exists no Ce ³⁺ in cubic Ce_0.5 Zr_0.5 O₂ solid solution and the Ce ⁴⁺ has not been reduced into Ce ³⁺ after annealing. The hyperfine structure in Zr_3d XPS spectrum has been observed for the Ce_0.5 Zr_0.5 O₂ solid solution. It shows that there may exist some Zr ions with a low valence state. The ionic conductivity measured by impedance spectroscopy showed that the cubic Ce_0.5 Zr_0.5 O₂ solid solution exhibits only the bulk conductivity. The bulk conductivity( σ=1.2× 10^-5 S/cm at 823 K, σ=2.1×10^-3 S/cm at 1123 K) is the same as that of CeO₂, but smaller than that of Y₂O₃-stabilized ZrO₂. Amarked curvature at T=823 Khas been observed in the Arrhenius plot of the bulk conductivity. The activation energy below 823 Kis lower than that above 823 K, and the reason has been discussed.

Synthesis and Characterization of Nanocrystalline Ce_0.8 Nd_0.2 O_2-δ Solid Solution

LIN Xiao-Min, LI Li-Ping, LUO Wei, SU Wen-Hui

2001, 22(4):  531-534. 

Asbtract ( )   PDF (568KB) ( )  

Related Articles | Metrics

The solid solution Ce_0.8 Nd_0.2 O_2-δ was prepared by sol-gel method. The XRD measurements showed that the product obtained by sintering the fresh gel at 200 ℃ crystallized in a single fluorite structure and its grain size was calculated to be ca. 7.2 nm by Scherrer formula. With the increase of sintering temperature, the grain size of solution increases. Afew of Ce ³⁺ ions were detected by EPRmeasurement. The first-order Raman spectra of the solid solutions exhibited two peaks. The strong band F_2g mode at a lower frequency is assigned to symmetric breathing mode of the oxygen atoms around cerium ions, while the weak band at ca. 570 cm^-1 is related with the existence of oxygen vacancies. With the grain decrease, the F_2g mode shifts to the lower frequency, while the half height width becomes broaden. The ionic conductivity for the solid solution Ce_0.8 Nd_0.2 O_2-δ at 500 ℃( σ 500 ℃ ) is 2.65×10^-3 S·cm^-1, and the activation energy is 0.82 eV.

Synthesis and Characterization of Bis(1,10-phenanthroline) tri(trans-2,3-dimethylacrylato) Lanthanide(Ⅲ) Dinuclear Complexes

LU Wei-Min, WU Bin, WANG Li-Na

2001, 22(4):  535-538. 

Asbtract ( )   PDF (206KB) ( )  

Related Articles | Metrics

Novel dinuclear lanthanide complexes, [REL₃(phen)]₂(RE=La, Ce, Pr, Nd, Sm, Eu; L=trans-2,3-dimethylacrylate, phen=phenanthroline), have been synthesized and characterized by IR, NMR, UVspectroscopy and elemental analysis. The single crystal of [LaL₃phen]₂ has been determined by X-ray crystallography, which crystallizes in the monoclinic, space group P₂ 1/n with Z=2, cell dimensions a=1.2962(4) nm, b=1.3283(4) nm, c=1.5485(5) nm, β=95.45(2)°. The structure was refined to R=0.033 for observed 3112 reflections and consists of centrosymmetric dinuclear molecule. Lanthanum atoms are bridged by two bidenate and two terdentate carboxylato groups with La…La separation of 0.4094 nm. Each Lanthanum atom is nine coordinate and exhibits a distorted tricapped trigonal prism. The La—Oand La—Nbond distances are in the range of 0.2460 —0.2756 and 0.2718—0.2760 nm, respectively.

Hydrothermal Synthesis and Characterization of Bixbyite Mn₂O₃ Powder

LIU Xing-Quan, CHEN Zhao-Yong, LIU Pei-Song, YU Zuo-Long

2001, 22(4):  539-541. 

Asbtract ( )   PDF (178KB) ( )  

Related Articles | Metrics

The pure bixbyite Mn₂O₃ was prepared by first applying in-situ redox precipitation hydrothermal synthesis method under the very mild conditions, and characterized by XRD, TEM, BETand TGA. The effects of alkalinity, crystallization time and temperature on the product were investigated. The results demonstrated that the alkalinity has an obvious effect on the product whereas the crystallization time and temperature has only a little influence on the product. Too low alkalinity results in no formation of product, and too high alkalinity leads to no formation of pure product with a smaller particle size. Under optimized conditions, the pure bixbyite Mn₂O₃ powder with a better morphology and distribution can be obtained. The average diameter of product is approximate to 80 nm. The normal LiMn₂O₄ spinel used as cathode material can be prepared using as synthesized bixbyite Mn₂O₃ as manganese precursor at 650 ℃ for 2 h by solid state reaction.

Quartz Crystal Microbalance Immunosensor for Schistosoma-japonicum

WU Zhao-Yang, HE Chun-Ping, WANG Shi-Ping, SHEN Guo-Li, YU Ru-Qin

2001, 22(4):  542-546. 

Asbtract ( )   PDF (714KB) ( )  

Related Articles | Metrics

Aquartz crystal microbalance(QCM) immunosensor has been developed for the direct determination of schistosoma-japonicum-infected rabbit serum(Sj-IRS). Self-assembled monolayers(SAMs) with carboxyl groups were first coated on the gold electrodes of the quartz crystal resonators by spontaneous adsorption of mercaptopropionic acid(MPA). Schistosoma-japonicum molecular antigen of 32 kDmolecular weight(SjAg32) was then covalently attached to the crystal surface via EDCand NHS. The results show that the SAM-coated quartz crystal has a better oscillating behavior in aqueous solutions than ordinary polymer coated quartz crystal. The QCMimmunosensor was used for the detection of infected rabbit serum(IRS49-2000), and a maximum titer of 1:1500 was achieved. Finally, several rabbit serum samples with different degrees of infection were tested. The results show that the QCMimmunosensor is suitable for detecting the infection degree of IRS.

Studies on an On-line Reaction of Micro Lactate Dehydrogenase in Capillary Electrophoresis Using Electrochemical Detection

YANG Wen-Chu, YU Ai-Min, CHEN Hong-Yuan

2001, 22(4):  547-551. 

Asbtract ( )   PDF (1429KB) ( )  

Related Articles | Metrics

The method for an on-line reaction of micro lactate dehydrogenase in capillary electrophoresis using electrophoretically mediated micro-assay(EMMA) coupled with electrochemical detection(EC) was developed. The running electrolyte(pH 9.2) was composed of 50 mmol/L Tris HCl, 10 mmol/Lnicotinamide adenine dinuceotide(NAD⁺), 5.0 mmol/Llithium lactate and 0.2 mmol/Lcetylpridinium bromide(CPB). LDHwas injected into the capillary. As it migrated electrophoretically in the capillary, LDH catalyzed the reaction between lactate and NAD⁺. The product NADH of the enzyme-catalyzed reaction was monitored by a bundle of carbon fiber electrode(150 μm diameter) held at +0.8 Vvs. SCE. The detection limits for LDHactivity using constant voltage mode and zero-voltage mode in EMMAwere determined to be 11×10^-9 Uand 60×10^-10 U, respectively. The formulae concerning the width or the height of the plateau in the electropherogram for EMMAwere deduced, and some significant conclusions were drawn from these formulae. The developed method has been used for the determination of ultramicro LDHactivity in serum with satisfactory results.

Resolution of Multicomponent Overlapping NMR Signals Using an Immune Algorithm and Genetic Algorithm

SHAO Xue-Guang, SUN Li

2001, 22(4):  552-555. 

Asbtract ( )   PDF (197KB) ( )  

Related Articles | Metrics

The natural immune system has many interesting characteristics and powerful abilities from the information view points, such as recognition of antigen, production of antibody and learning with memory cell. In this paper we proposed a new algorithm by imitating the defending process of immune system to resolve the overlapping NMRsignals of mixed animo-acid with the aid of genetic algorithm. The method takes an overlapping NMRsignal as an antigen, and the standard NMRsignal of estimated components as antibodies. The antigen is subtracted iteratively by the antibodies until the residual approaches to zero and then the information of every components will be extracted. It was proven by the results that the method is a convenient tool for the resolution of multicomponent overlapping NMR signals, and is a promising way to analyze the mixtures or complex bio-moleculars with the aid of database.

A Study on Chloride Ion-selective Electrode Transient Potentiometry

SHI Sheng-Hua, GUO Yan-Li, SUO Zhi-Rong

2001, 22(4):  556-559. 

Asbtract ( )   PDF (227KB) ( )  

Related Articles | Metrics

When 0.10 mol/L KNO₃ blank solution and Cl^- test solution are switched each other, day-to-day reproducibility of the peak height ΔE_p of transient signal responded by Cl^--selective electrode is very good. The detection limit of Cl^--selective electrode and the intercept of ΔE_p～p(Cl) straight line accord with both values calculated by K_sp (AgCl) respectably. At positive activity step, the jump time of transient signal is smaller than 1.5s, the fast and accurate analysis of test solution in small volume may be achieved. The potential variance velocity in different stage of transient signal may be explained by the variance of Cl^- hydration Gibbs free energy, ΔG_h(Cl^-)=ΔG_h⁰ (Cl^-)+ RTln (a Cl(H₂O)_n^- / a⁰ )/(p (Cl_g^-)/ p⁰ ), where a⁰ =1 mol/L, p⁰=1.013×10^-5 Pa, ΔG_h⁰ (Cl^-)=-337 kJ/mol. At the start of positive activity step, p (Cl_g^-) is very small, a Cl(H₂O)_n^- larger, then ｜ΔG_h(Cl^-)｜ the smallest. Because the smaller the ｜ΔG_h(Cl^-)｜, the larger the hydration velocity of Cl(H₂O)_n^-, the jump of transient potential is the fastest. At the approach of peak potential, both p (Cl_g^-) and ｜ΔG_h(Cl^-)｜ are almost the largest, the dehydration velocity of Cl(H₂O)_n^- the smallest, then the jump of transient potential very slow. At the start of negative acitivity step, a Cl(H₂O)_n^- is almost zero, p (Cl_g^-) the largest, then ｜ΔG_h(Cl^-)｜ the largest. Contrary to the dehydration of Cl(H₂O)_n^-, the hydration velocity of Cl_g^- is the largest, then the jump of transient potential from peak potential to positive direction the fastest. With the decrease of p (Cl_g^-) and the increase of a Cl(H₂O)_n^-, both the ｜ΔG_h(Cl^-)｜ and hydration volecity of Cl_g^- are getting smaller and smaller, so the transient potential tends slowly to the base line.The automatically switching setup of activity step used in this experiment is hom made, the setup is provided with both injectors for blank and test solutions.

Preliminary Research on Pulsed-Electrospray Phenomenon

LU Yu, BIAN Li-Ping, ZHOU Feng, SUN Ping, YANG Peng-Yuan, GUO Yin-Long, YU Chong-Tian

2001, 22(4):  560-562. 

Asbtract ( )   PDF (486KB) ( )  

Related Articles | Metrics

A novel pulsed electrospray device is reported in this paper. With such an apparatus, the observation of the electrospray process under the pulsed high voltage conditions has been successfully made with microscope, oscilloscope and mass spectrometer. By using pulsed spray technique, the sample flow rate can be averagely decreased to <100 nL/min. After increasing the frequency of pulsed high voltage, it is hopefully to directly combine this device to time of flight mass spectrometer and obtain a great enhancement both in signal to noise ratio and in detection sensitivity for mass spectrometry analysis.

Determination of Gastrodin in Gastrodia elata Blume by HPLC with ELSD and DAD

WEI Yang, DING Ming-Yu, LI Hong-Xia

2001, 22(4):  563-565. 

Asbtract ( )   PDF (494KB) ( )  

Related Articles | Metrics

Anormal phase high performance chromatographic method with evaporative light scattering detector(ELSD) and diode array detector(DAD), using n-hexane/methanol/ethyl acetate(volume ratio 6:3:2 ) as the mobile phase, was established for the direct determination of active constituents-gastrodin(GA) in the ethanol extracts of Gastrodia elata Blume. An silica gel column Zorbax RX-SIL[46 mm (i.d.)×25 cm, 5 μm] was employed. Regression equations revealed the linear relationships( r=0998 and 0999) between the peak areas of GAmeasured by ELSDand DADand its concentration. The recoveries of GAmeasured by ELSDand DADare 104.22% and 97.65%, respectively. The contents of GAmeasured by ELSDand DADare 139 mg/g(2.79% RSD) and 12.1 mg/g(2.99% RSD) respectively in Gastrodia elata Blume. The detection limits of ELSDand DAD( S/N=3) are 3 mg/Land 1 mg/Lrespectively. This method is simple, selective and sensitive.

A Novel Bonded Stationary Phase for Chiral Ligand Exchange-Chromatography

LONG Yuan-De, WANG Qun-Biao, HUANG Tian-Bao

2001, 22(4):  566-568. 

Asbtract ( )   PDF (1106KB) ( )  

Related Articles | Metrics

Anovel chiral bonded stationary phase(CBSP) for ligand exchange chromatography was prepared by bonding (S)-1,2,3,4-tetrahydro-3-isoquinoline carboxylic acid prepared from L-Phe to YWG-80 silica gel via 3-glycidyloxypropyltrimethoxysilane as a coupling agent. Chromatographic resolutions of some DL-amino acids were achieved on the CBSPby using an aqueous solution of 2 mmol/L N(C₂H₅)₃, 2 mmol/L HAc and 0.2 mmol/L Cu(Ac)₂ as the mobile phase with a flow rate 10 mL/min, column temperature 50 ℃ and detection at 254 nm. The enantioselectivity α of the DL-amino acids on the CBSPwas found to be between 1.11 and 1.51. The elution order of Disomer before Lisomer on the CBSPwas observed for all the DL-amino acids resolved except DL-Val. For DL-Pro, DL-Val and DL-Leu the elution order through the CBSPwas different from that through the chiral ligand exchange phases prepared from L-Pro or L-hydroxyl proline with a five membered ring structure.

Studies on the Substituent Effects on the Oxidation of New Schiff Base Complexes with PhIO

CHEN Xin-Bin, YANG Yan, ZHU Shen-Jie, GUI Ming-De

2001, 22(4):  569-572. 

Asbtract ( )   PDF (599KB) ( )  

Related Articles | Metrics

The kinetic properties and the substituent effects of the oxidations of new Schiff base complexes Mn₂L{L=bis[ N,N'-alkylene-2,2'-(arylmethylene)bis(3,4-dimethylpyrrole-5-aldimino)]} with PhIOwere studied by UV-Vis. The results showed that the oxidations are the first order for the complexes. We also found that being contrary to the electron donating groups, the electron withdrowing groups on the phenyl groups or/ and the phenylene groups of the complexes could increase their stabilities; with respect to the antioxidation against PhIO, the substituent effects on the phenylene groups of the complexes are greater than those on the phenyl groups; there are the linear relationships between the reaction kinetic constant k and the substituent constant σ:-lg k=0.5215 σ + 1.326 for the complexes with substituents on the phenyl groups and -lg k=0.8271[( σ_m+ σ_p)/2]⁺1.506 for the complexes with substituents on the phenylene groups.

Crystal Structure and Preparation of Wilforlide A

LI Liang-Xue, LIU Ji-De, YIN Ye-Gao, SHEN Liao-Rong, SU Hong-Ying

2001, 22(4):  573-576. 

Asbtract ( )   PDF (1236KB) ( )  

Related Articles | Metrics

Apure wilforlide Awas separated from the ethanolic extract of tripterygium wilfordii Hook. F. root. The compound was characterized by IR, ¹HNMRand microanalysis. Its crystal structure was also determined by X-ray crystallography. The title compound is formulated as C₃₀ H₄₆ O₃ with formulae weight M_r=454.70. Its crystal belongs to orthorhombic system with P2₁2₁2₁ space group. The crystal cell parameters are a=0.732(4) nm, b=1.283(7) nm, c=2.693(6) nm; V=2.5327 nm³, Z=4, D_c=1.192 g·cm^-3, μ (Mo Kα )=0.695 cm^-1, F (000)=1107. The final R=0.039, R_W=0.044. The title compound is a five membered ring terpene, whole skeleton of molecule stretches folded. The results of AM1 calculation shows that the molecule is polar and reactive to the nucleophilic and redox reactions.

Chemical Modification of Human Plasminogen

LIANG Fang, WU Yi-Hui, CAO Hai-Shi, GUO Hui-Yun, LIU Lan-Ying, SUN Hong, CHEN Wei-Jin, LIU Shu-Ying

2001, 22(4):  577-580. 

Asbtract ( )   PDF (200KB) ( )  

Related Articles | Metrics

The chemical modification of human plasminogen(HPg) was studied with NAI, 1,2-cyclohexanodine, Ch-T, and EDCas the modification reagents on its Tyr, Arg, Met and carboxyl groups. The results indicate that Tyr and Arg residues are not activity dependent groups, while Met and carboxyl groups played an important role on HPg's activity. The kinetic analysis demonstrates that one Met residue and two carboxyl groups are essential for HPg's activity.

Fluorescence Spectral Studies on the Coordination of Calix[4]arenes Bearing Boronic Acid Moieties with Amino Acids

LU Kui, WU Yang-Jie, LI Yong-Hong, SHI Ya-Lin, ZHOU Zhi-Xian

2001, 22(4):  581-583. 

Asbtract ( )   PDF (163KB) ( )  

Related Articles | Metrics

Coordination of ten kinds of calix[4]arenes bearing boronic acid moieties with four kinds of amino acids was studied by using fluorescence spectrometry. The stability constants( K_s) of the complexes of calix[4]arenes bearing boronic acid moieties with amino acids and Gibbs free energy change(-Δ G °) of the coordination reactions were calculated according to the modified Hilderbrand Benesi equation. The results obtained indicated that the coordination abilities and selectivities of Lalanine with calix[4]arenes bearing boronic acid moieties were stronger than that of the other amino acids, and that the above calix[4]arene derivatives could be used for identification of D-alanine.

Synthesis of Chiral Intermediate (3S,5S,6S)-3,7-Dimethyl-5,6-dihydroxy-7-en-octanal of Didemnaketals Analogue

JIA Yan-Xing, WU Bin, TU Yong-Qiang

2001, 22(4):  584-586. 

Asbtract ( )   PDF (405KB) ( )  

Related Articles | Metrics

Astereoselective synthesis of (3 S,5S,6S )-3,7-dimethyl-5,6-dihydroxy-7-en-octanal, a key intermediate, for the synthesis of the HIVinhibitory didemnaketals analogue, was performed via a series of reactions from the natural(+)-pulegone. In this approach, an interesting and valuable diastereo recognizable reaction between tertiary hydroxyepoxides and PCCwas found. Therefore, the mixture of compounds 8 and 9 was treated with PCCto recover 8 in 93% yield and de 98% purity.

Using Molecular Graphics, Molecular Mechanics, Quantum Chemistry and Electrostatic Potential Methods to Study Structure-Property Relationship on Pesticides(ⅩⅢ)── Studies on Three-dimensional Quantitative Structure-activity Relationship Betweenthe Structuresof O-(4-Quinazolinyl)oxime Ethers and Their Antiviral Activity

FANG Ya-Yin, WANG Xia, LI Hui-Ying, MA Yi, YUAN Man-Xue, HUANG Run-Qiu, LAI Cheng-Ming

2001, 22(4):  587-590. 

Asbtract ( )   PDF (271KB) ( )  

Related Articles | Metrics

In this paper, Comparative Molecular Field Analysis(CoMFA) method is applied to study the three-dimensional quantitative structure activity relationship(3D-QSAR) on a set of O-(4-quinazolinyl)oxime ethers. The molar refractivity(MR) and the dipole moment(DIPOLE) of the molecules here can be used as the third and the fourth field respectively in CoMFAstudies. Then the results of PLSanalysis are: r_cv² (leave one out)=0.443, r²(no validation)=0.932, which show that the model established is reasonable, and most of the predications are in good agreement with the experiment. Based on the contour maps, a hypothetical interaction model can be obtained, thus a novo design can be started from it.

Molecular Recognition Studies on Supramolecular Systems ──The Binding Ability and Molecular Selectivity of Bridged Bis(cyclodextrin)s with Model Substrates

LIU Yu, YOU Chang-Cheng

2001, 22(4):  591-597. 

Asbtract ( )   PDF (1097KB) ( )  

Related Articles | Metrics

The research progress in the molecular recognition studies on bridged bis(cyclodextrin)s in recent years is reviewed. The results are described and discussed in aspects of hydrophobic interaction, multiple recognition, size/shape matching, thermodynamic properties, and the application of molecular recognition of cyclodextrin dimers.

Studies on DNA Cleaved by Seryl-histidine Dipeptide

WAN Rong, WANG Ning, ZHAO Yu-Fen

2001, 22(4):  598-600. 

Asbtract ( )   PDF (177KB) ( )  

Related Articles | Metrics

Linear and supercoiled DNAwere cleaved by HPLCpurified seryl-histidine dipeptide(SH). It was found that the DNAfragments produced by the reaction of SHand DNAcould be ligated together by T₄ DNAligase. This result implied that the SHwas the first example of the ion free artificial DNAcleavage agent that could split DNAby hydrolysis mechanism.

Trimethylsilylcyanation of Aromatic Aldehydes Catalyzed by BINOL-Li Salt

LIU Da-Xue, WANG Quan, ZHANG Li-Chen, DA Chao-Shan, WANG Rui

2001, 22(4):  601-602. 

Asbtract ( )   PDF (427KB) ( )  

Related Articles | Metrics

Aseries of aromatic cyanohydrins and their Osilyl ethers have been synthesized by trimethylsilylcyanation of aromatic aldehydes using a catalyst generated in situ from optically active R-(+)-1,1'-2-bisnaphthol with n-butyl lithium. Mandelonitrile was prepared in an isolated yield 70% with more than e.e.=60%. The effect of solvents and the amount of catalyst on enantioselectivity was also investigated.

Ab initio Study on the Electronic Structure of Mo₂[(p-tol)NCHN(p-tol)]₄ and Its Cation

YANG Guang-Hui, ZHANG Hong-Xing, TANG Au-Chin

2001, 22(4):  603-606. 

Asbtract ( )   PDF (491KB) ( )  

Related Articles | Metrics

Molecular orbital calculations by the B3LYPmethod have been carried out on the electronic structure of Mo₂(form)₄ and [Mo₂(form)₄]⁺, where (form)^-=[( p-tol)NCHN( p-tol)]^-. The nature of the quadruple-metal metal bonds in the Mo—Mo was discussed in detail. Molecular orbital ordering have little difference with the result obtained by using the SCF-Xα-SW method. Electronic absorption spectra for Mo₂(form)₄ and [Mo₂(form)₄]⁺ have been calculated by the single excitation configuration interactions(CIS) method and were compared with experimental result.

Theoretical Calculation of RRKM Microcanonical Dissociation Rate Constant of Small Linear Carbon Clusters C_n(n=3～6)(Ⅰ)

WANG Hai-Yan, ZHANG Qiang, CHEN Hong, HUANG Rong-Bin, ZHENG Lan-Sun

2001, 22(4):  607-609. 

Asbtract ( )   PDF (460KB) ( )  

Related Articles | Metrics

Ab initio calculation has been applied to calculate the dissociated pathways of small carbon clusters. Linear C₃, C₄, C₅ and C₆ and their transition states were optimized at MP2/6-31G ^* level, and their vibration frequencies were also calculated and analyzed. Based on the calculations, the energy barriers of the clusters were computed and their microcanonical decomposition rates of different dissociation pathways were estimated by RRKMtheory, and the result shows that the small carbon clusters tend to dissociate to the fragments with closer sizes.

Preparation and Characterization of Nanometer Photocatalysis SnO₂@TiO₂

YAN Xiu-Ru, LI Xiao-Hong, SONG Kuan-Xiu, ZHAO Hai-Tao, CHEN Xiu-Zeng

2001, 22(4):  610-613. 

Asbtract ( )   PDF (1054KB) ( )  

Related Articles | Metrics

SnO₂@TiO₂ coated particles have been prepared with Ti(OC₄H₉)₄ by hydrolysis cross link TiO₂ on active SnO₂ hydrated particle. Its morphology and structure were characterized by XRD, TEM, and BETmethod. In order to improve the photocatalytic degradation activity of SnO₂@TiO₂ for dichlorvos, the conditions of preparing were selected and the better photocatalytic activity were received. The result indicated that: SnO₂@TiO₂ was composited with ranatase TiO₂ and rutile SnO_2. When mass fraction of TiO₂ in SnO₂@TiO₂ is 56.45%, water content in SnO₂ alcohol solution is 20%, volume fraction of Ti(OC₄H₉)₄ in alcohol solution is 34.5%, and ignition temperature of SnO₂@TiO₂ is 680 ℃, the best photocatalytic activity of SnO₂@TiO₂ were received. The other factors of effect of SnO₂@TiO₂ photocatalytic activity were given.

Calculation of Chemical Bond Parameters in RBa₂Cu₄O₈ (R=Dy,Ho,Er,Tm,Yb) and Y₂Ba₄Cu₇O_14.3

WU Zhi-Jian, YANG Ming, ZHANG Si-Yuan

2001, 22(4):  614-616. 

Asbtract ( )   PDF (402KB) ( )  

Related Articles | Metrics

Chemical bond parameters in RBa₂Cu₄O₈(R=Dy, Ho, Er, Tm, Yb) and Y₂Ba₄Cu₇O_14.3 were calculated by using complex chemical bond theory. The results indicated that the bond covalency in CuOchain was larger than that in CuO₂ plane. For metal atoms, the bond covalency of five coordinated case was larger than that of six coordinated case.

Solubilization of Polycyclic Aromatic Hydrocarbons in F127 and P123 Aqueous Micellar Solutions

ZHENG Yu-Ying, JIANG Lin-Qin, ZHAO Jian-Xi, XU Xiu-Zhi

2001, 22(4):  617-621. 

Asbtract ( )   PDF (729KB) ( )  

Related Articles | Metrics

The solubilization of naphthalene, anthracene and pyrene, in both F127 and P123 aqueous micellar solutions has been characterized by UVmethod. These aromatic hydrocarbons were confirmed to incorporate in the micellar cores. The model of stepwise association equilibrium was used to analyze the experimental results and the first stepwise association constant K₁ between solubilizate monomer and vacant micelle was thus obtained. It was found that the values of K₁ increased with increasing the benzene cycle number of the aromatic hydrocarbons. The average number of solubilizating molecules corresponding to each PO-group in the mcellar cores was verified to be consistency for both F127 and P123 This result suggests that the volume of the micellar core is an important factor to determine the amount of aromatics incorporating into Pluronic micelles. The amount was lineally enhanced with increasing the volume of the micellar core. The stability in planar ring of the molecule of polycyclic aromatic hydrocarbon also affected its solubilization. It was shown by the solubilization isotherms that anthracene and pyrene have a higher efficiency in solubilization compared with naphthalene.

Formation and Photodissociation of Chromium/Phosphorus Binary Clusters

HAN Chun-Ying, XING Xiao-Peng, GAO Zhen, ZHU Qi-He

2001, 22(4):  622-625. 

Asbtract ( )   PDF (212KB) ( )  

Related Articles | Metrics

Chromium/Phosphorus binary clusters were produced by direct laser ablation and analyzed by tandem time-of-flight mass spectrometer. The main clusters formed were rich in phosphorus. There is an oscillation in CrP_m⁺ series(the peaks with even m are stronger than those with odd m, especially the peaks of CrP₄⁺ and CrP₈⁺ are the strongest) and this may be ascribed to the specific stability of P₄ structure. There are some strong peaks such as Cr₃P₈⁺, Cr₄P₉⁺, Cr₅P₁₁⁺, Cr₆P₁₂⁺, Cr₈P₁₄⁺, etc., which don't change with the change of the ratios of Cr to Pin the samples, and their stability could be explained with an electron model of valence electrons filling the d orbitals of Cr. The results of photodissociation just accord with the model.

Theoretical Study on Effect of Bromination on Molecular Properties of Hypocrelin

YI Ping-Gui, YU Qing-Sen, SHANG Zhi-Cai, LIN Rui-Sen

2001, 22(4):  626-629. 

Asbtract ( )   PDF (543KB) ( )  

Related Articles | Metrics

AM1 method has been used to calculate the molecular properties of hypocrellin A, hypocrellin Band their substituted bromine derivatives, such as the heat of formation, HOMOor LUMOenergy levels, intramolecular hydrogen bond and dipole moment. The effect of bromination on the properties of hypocrellin molecules has also been discussed.

Studies on a Fuel Cell with Solid Electrolyte of SrCe_0.9 Gd_0.1 O₃

LÜ Zhe, LIU Jiang, HUANG Xi-Qiang, LIU Zhi-Guo, LIU Wei, HE Tian-Min, SU Wen-Hui

2001, 22(4):  630-633. 

Asbtract ( )   PDF (333KB) ( )  

Related Articles | Metrics

Solid electrolyte of SrCe_0.9 Gd_0.1 O₃ with proton conduction was sintered by solid reaction method, and the properties of a fuel cell with this material as the electrolyte were also investigated. The results show that the output voltage depends on temperature. The phenomena should be contributed to the complex conducting mechanism of this electrolyte. By studying the impedance spectroscopy of the electrolyte material in the working environment of a fuel cell, we found that the conducting types vary with the variation of atmosphere. According to the results of this experiment, the best working condition of this kind of electrolyte was also determined.

Studies on the Metastable Phase Equilibrium of Na⁺, K⁺, Mg²⁺ ∥Cl^-, SO₄ ^2--H₂O Quinary System at₃₅ ℃

JIN Zuo-Mei, ZHOU Hui-Nan, WANG Li-Sheng

2001, 22(4):  634-638. 

Asbtract ( )   PDF (560KB) ( )  

Related Articles | Metrics

This paper presents the experimental data of metastable phase equilibrium of Na⁺, K⁺, Mg ²⁺ ∥Cl^-, SO₄^2- H₂Oquinary system at 35 ℃, from which the metastable phase diagram is drawn. It consists of nine regions of crystallization saturated with sodium chloride, potassium chloride, glasserite(3K₂SO₄·Na₂SO₄), leonite(K₂SO₄·MgSO₄·4H₂O), kainite(KCl·MgSO₄·2.75H₂O), thenardite(Na₂SO₄), astrankit(MgSO₄·Na₂SO₄·4H₂O), carnallite(KCl· MgCl₂·6H₂O), magnesium sulfate hexahydrite(MgSO₄·6H₂O) and bischofit(MgCl₂·6H₂O). Alarge difference is found between the obtained metastable phase diagram at 35 ℃ and Van't Hoff's stable phase diagram at 25 ℃. The crystallization regions of schoenite(K₂SO₄·MgSO₄·6H₂O), epsomite(MgSO₄·7H₂O), magnesium sulfate pentahydrite(MgSO₄·5H₂O) and starkeyite(MgSO₄·4H₂O) disappear and the crystallization regions of leonit and astrankit are greatly incresed. Also there is much difference between the obtained metastable phase diagram at 35 ℃ and the metastable phase diagram at 25 ℃. The crystallization regions of schoenite(K₂SO₄·MgSO₄·6H₂O) and epsomite disappear and arise the crystallization regions of leonite and kainite. It is found that the crystallization region of low hydrate kainite(KCl·MgSO₄·2.75H₂O) exists in the metastable phase equilibrium of Na⁺, K⁺, Mg ²⁺ ∥Cl^-, SO₄^2- H₂Oquinary system at 35 ℃.

Studies on LiNd(PO₃)₄ Crystal by Thermal Analysis

MA Chang-Qin, WANG Xu-Ning, LU Qing-Ming, ZHANG Wen-Xing, LIU Jin-Xiang

2001, 22(4):  639-641. 

Asbtract ( )   PDF (953KB) ( )  

Related Articles | Metrics

The study of LiNd(PO₃)₄ crystals was carried out by TGand DTAin different atmosphere (nitrogen and air). The TGand DTAcurves were presented. The thermal decomposition mechanisms in nitrogen and air were discussed. The results indicate that the major products of thermal decomposition are Nd₄(P₂O₇)₃ and NdP₂O₇ in N₂ and air, respectively.

Electroluminescent Devices Based on Triplet Materials Cu₄ Doped PVK and Special Increasing Emitting Mechanism

ZHANG Jing-Ying, KAN Shi-Dong, MA Yu-Guang, ZHANG Guo, SHEN Jia-Cong

2001, 22(4):  642-644. 

Asbtract ( )   PDF (456KB) ( )  

Related Articles | Metrics

The bilayer devices using a mixture film of triplet emitting material Cu₄(C≡CPh₄)₄L₂[L=1,8 bis(diphenyl phosphino)-3,6-dioxaoctane](Cu₄) and hole transport polymer poly(9-vinylcarbazole)(PVK) as emitting layer, electron transport material TAZas the electron transport layer were prepared. Different devices that formed by varied Cu₄ ratios show different light emitting properties through singlet-triplet and triplet triplet-energy transfer. The result showed a new application of triplet emitting materials.

The Oxidative Carbonylation of Amines Catalyzed by Organic Gold(Ⅰ) Complexes

SHI Feng, DENG You-Quan, SIMA Tian-Long, GONG Cheng-Ke

2001, 22(4):  645-647. 

Asbtract ( )   PDF (169KB) ( )  

Related Articles | Metrics

At 200 ℃ and 50 mPa, the oxidative carbonylation of amines catalyzed by organic gold complexes HAuCl₄, Au(PPh₃)Cl, Au(PPh₃)₂Cl, Au(PPh₃)NO₃ and [Au(PPh₃)]₂Safforded R(NHCO₂CH₃) n with a high conversion and selectivity. The best results were obtained when using the catalyst Au(PPh₃)Cl in the presence of PPh₃. The catalytic efficiency of catalytic Au(PPh₃)Cl was compared to Pd(PPh₃)₂Cl₂, e.g. the conversion was 97.2% and selectivity was 89% when using catalyst Au(PPh₃)Cl in the presence of PPh₃, while the conversion was 98.8% and selectivity was 86% when using catalyst Pd(PPh₃)₂Cl₂ in the presence of PPh₃. The experimental results suggested that Au complexes might be promising catalysts instead of Pd catalysts for the oxidative carbonylation of amines to carbamates.

Investigation of Second-order Optical Nonlinearities of Push-pull Azo-methine Dye LB Monolayer Film

LI Fu-You, LIU Ting-Ting, ZHAO Chao-Yang, JIN Lin-Pei, ZHAO Xing-Sheng, GUO Jian-Quan

2001, 22(4):  648-650. 

Asbtract ( )   PDF (182KB) ( )  

Related Articles | Metrics

Aseries of amphiphilic azo methine dyes with different relative positions of electron accepting groups, (E)-Noctadecyl-2-[2-(4-N,N-dimethylaminophenyl)azomethinyl]quinolinium iodide(QN2), (E)-Noctadecyl-4-[2-(4-N,N-dimethylaminophenyl)azomethinyl]quinolinium iodide(QN4) and (E) Noctadecyl-6-[2-(4-N,N-dimethylaminophenyl)azomethinyl] quinolinium iodide(QN6) were synthesized. These dye molecules were successfully transferred onto quartz by Langmiur-Blodgett(LB) technique. We studied the second harmonic generation(SHG) of their monolayers and found that the effect of relative position of acceptor group on SHGcan not be negligible.

Thermodynamics of Ion pair of [MgSO₄]⁰ in i-PrOH Water Mixed Solvent

WANG Jie, YANG Jia-Zhen, ZHANG Ru-Bo, LU Dian-Zhen, ZHANG Li-Tian

2001, 22(4):  651-653. 

Asbtract ( )   PDF (178KB) ( )  

Related Articles | Metrics

The standard second ionization constant of sulphuric acid, K₂ and the standard association constant of ion pair [MgSO₄]⁰, K_D, in_0.05 molar fraction i-PrOH-water mixture at five temperatures, from 278.15 to 318.15 Kwere determined from precise emf measurements of different cells without liquid junction. The results have been discussed in term of the solute-solvent interaction and have been compared with those results in water.

Surface-enhanced Raman Scattering of Pyridine Adsorbed on Some Metal Nanowire Arrays

PAN Gu-Ping, XUE Kuan-Hong, SUN Dong-Mei, XU Shi-Min, KONG Jing-Lin, YAO Jian-Lin, XIE Yong, TIAN Zhong-Qun, WANG Guang-Hou

2001, 22(4):  654-656. 

Asbtract ( )   PDF (489KB) ( )  

Related Articles | Metrics

Nanowire arrays of various metals were fabricated from the template of porous alumina. We observed the strong surface-enhanced Raman scattering(SERS) signals of the adsorbed molecules such as pyridine not only at the noble metals nanowires that exhibit a high SERSactivity, but also at Ni, Co nanowires that are normally considered to be non-SERSactive substrates. The intensity of the species adsorbed at Ni nanowires is stronger than that on the conventionally roughened metal surface, and depends on the length of the nanowires out of alumina matrix. The metal nanowire arrays can be used as SERSactive substrates.

Theoretical Study of the Benzene Cation

LIU Ya-Jun, KUANG Ping-Xian, HUANG Ming-Bao

2001, 22(4):  657-659. 

Asbtract ( )   PDF (163KB) ( )  

Related Articles | Metrics

The Jahn-Teller distorted states, ²B_2g and ²B_1g of the benzene radical cation have been studied by using ab initio MPn and SDCImethods. The calculations indicate that ²B_2g is the ground state of the benzene cation and that ²B_1g is higher in energy than₂ B 2g and represents a saddle point. The calculated isotropic and anisotropic hyperfine coupling constants for the ²B_2g state are in excellent agreement with those obtained from the ESRexperiments. It is concluded that the benzene cation is in the ²B_2g Jahn-Teller distorted state.

Studies on the Relationship Between the Crystal Form of TiO₂ and Its Photocatalyzing Degradation Efficiency

GAO Wei, WU Feng-Qing, LUO Zhen, FU Ju-Xia, WANG De-Jun, XU Bao-Kun

2001, 22(4):  660-662. 

Asbtract ( )   PDF (384KB) ( )  

Related Articles | Metrics

Aseries of studies were carried out to investigate the effect of crystal forms of TiO₂ on the activities in the photocatalyzing degradation of aqueous methyl orange. It is shown that the rutile could hardly catalyze the degradation of the methyl orange and anatase is more effective for catalyzing the degradation than rutile. Moreover, the activities of mixed crystalline forms of TiO₂ vary with the change of the values of A/R, the best of which is 9:1. Some characterizations with XRD, XPSand SPSwere performed and explanations to the phenomena that exist in photodegradation are given out.

Change Tendency of Photocatalytic Activity in System of Perovskite(ABO₃) Type Oxide and Analysis

BAI Shu-Lin, FU Xi-Xian, SANG Li-Xia, YANG Qiu-Hua, WANG Jun-Zhen, ZENG Shu-Lan

2001, 22(4):  663-665. 

Asbtract ( )   PDF (524KB) ( )  

Related Articles | Metrics

The perovskite(ABO₃) type oxides have a photocatalytic activity that can be characterized with decolorization of some organic dyes under irradiation of mercury lamp. The experimental results show that the photocatalytic activity of ABO₃ increases with increasing atomic number of atom B(Ti—Co) when A-site atom keeps constant. It is connected with the rise of Allred Rochow electronegativity of atom B, the decrease of ABO₃ energy gap(energy defference between the filled p bands of O^2- and the unoccupied 3 d band of neighboring atom B) and the increase of the third atomic ionizaton potentials of atom B. It has been also proved that the photocatalytic activity of ABO₃ compounds increases with increasing χ_ARof atom A(Ca, Cd, Pb).

The Crystallizing Behavior of Sodium Dodecyl Sulfate Under a Electro-static Field

YANG Hu, YAN Xiao-Hu, WANG Zhi-Liu, CHENG Rong-Shi

2001, 22(4):  666-668. 

Asbtract ( )   PDF (370KB) ( )  

Related Articles | Metrics

It was confirmed that sodium dodecyl sulfate(SDS) in dilute water solution (higher than its critical aggregation concentration, but lower than its critical micelle concentration) can be crystallized under the treatment of an electro static field from TEM, X-ray diffraction and DSCexperiments. With the effect of the electro-static field, the high-order single-crystals can be formed, and its crystal structure was the same as that from the recrystallized sample in methanol as judged from X-ray diffraction spectra. In DSC, the enthalpy, corresponding to the first-order phase transition from order to disorder structure, was equal between these two samples, but the transition temperature was lower as its crystal size was smaller. On the contrary, the sample without the electro static field treatment only has much lower order structure.

Studies on Miscibility of Polyacetal with Novolak

WANG Xiao-Dong, ZHANG Qiang

2001, 22(4):  669-672. 

Asbtract ( )   PDF (546KB) ( )  

Related Articles | Metrics

The miscibility of polyacetal(POM) with Novolak was studied. It was found that POM/Novolak blends showed a lower critical solution temperature in their cloud point curve and the melting point decreasing by DSCtest. The interaction parameter( χ ) of POMand Novolak was calculated by Hoffman-Week's equilibrium melting point method and Flory equation. The investigation of FTIRfor POM/Novolak blends demonstrated that there was a hydrogen bond between the molecular chain of POMand Novolak, which resulted in the movement of absorption peak to a low frequency. All results certified that POMwas miscible with Novolak.

Compatibilizing Effect of Novolak on Toughness, Crystallite and Morphology of Polyacetal and Nitrile-Butadiene Rubber Blends

WANG Xiao-Dong, ZHANG Qiang

2001, 22(4):  673-677. 

Asbtract ( )   PDF (611KB) ( )  

Related Articles | Metrics

Compatibilizing effect of novolak on toughness, crystallite, and morphology of polyacetal(POM) and nitrile-butadiene(NBR) blends were investigated. It was found the POMand NBRwere immiscible system, and the compatibilization of POMand NBRcould be improved by addition of Novolak. As a result, Izod impact strength increased remarkably. The crystallite morphology of the blends under polarized light microscopy demonstrated that the size of spherulites of POMwas so large as to increase the brittleness of blends. The size of spherulites of POMcould be sharply reduced by mixing with Novolak, which suggested that the inner stress concentration in blends be diminished. POM/NBRblends exhibited a “sea island” morphology, where NBRwas the dispersed phase “sea” and POMwas continuous phase “island”. The morphology of POM/NBR/novolak(mass ratio 60/40/5) blends showed that there was not a “sea island” structure but a physical elastomer network. The elastomer network impeded the growth of craze and promoted the shear deformation of POMmatrix. As a result, a large amount of impact energy could be absorbed and the super toughness was thus obtained.

Synthesis and Characterizations of New Supports for Enzymes Immobilization from Poly(vinylene carbonate) and α-(2-Aminoethyleneamino)-ω-(2-aminoethyleneamino)-poly(ethylene oxide)

HUANG Jia-Xian, DING Lun-Han, CAO Zhe, LI Yue, JIANG Yan

2001, 22(4):  678-682. 

Asbtract ( )   PDF (514KB) ( )  

Related Articles | Metrics

In this paper, poly(ethylene oxide) end capped with amine groups(PEO) was prepared and dissolved with poly(vinylene carbonate)(PVCA) in DMFsolution. The solution was suspended in paraffin oil to carry out the crosslinking reaction and produce beadlike hydrophilic supports containing reactive cyclic carbonate groups for enzyme immobilization. In above reaction, PEOwas acted as both crosslinking agent and hydrophilic modifier of poly(vinylene carbonate). Evaluation of the supports using trypsin as a model enzyme shows that the specific activity of immobilized trypsin and amount of enzymes coupled to supports were related to PVCA/PEOratio, reaction time, concentration and pHvalue of enzyme solution, etc.. The amount of trypsin coupled and the specific activity reach their maximum at w (PVCA)/ w (PEG)=1/2. The optimal pHvalue for trypsin immobilized increases as compared with the optimal pHvalue for native trypsin. The K_m value of immobilized and native trypsin was determined to be 325 mmol/Land 152 mmol/L, respectively.

Studies on the Lipase Monolayer Film Self-assembly on the Nagatively Charged Poly(ethylene terephthalate) Substrate

LIN Xian-Fu, HE Lin, XU Li-Heng, LÜ De-Shui, CHEN Zhi-Chun

2001, 22(4):  683-686. 

Asbtract ( )   PDF (560KB) ( )  

Related Articles | Metrics

The PET-CO₂^- film was prepared and the lipase was assembled on the surface of the PET CO₂^- substrate. The structure of the surface and activity of lipase/PETmonolayer were studied by FTIR-ATRand AFMand other methods. As shown in the results, AFMimages of lipase/PETmonolayer indicated that the surface fluctuation is in the range of nanometer scale and the depth of monolayer is less than 15 nanometers. The performance activity of lipase/PETmonolayer self assembly film is above 2.0.

Surface Modification of Ion Exchange Membrane(Nafion^TM )── The Enhancement of Cation Selectivity by Plasma Polymerization Process

ZENG Rong, PANG Zhi-Cheng, YI Feng, ZHU He-Sun

2001, 22(4):  687-690. 

Asbtract ( )   PDF (516KB) ( )  

Related Articles | Metrics

An ultra thin anionic exchange layer containing —NH₂ and —CONH₂ was deposited on the surface of Nafion^TMmembrane. This layer was deposited from ethylene and ammonia using a glow discharge plasma polymerization technique. The SEM, ATR(attenuated total reflection) spectra and XPS(X-ray photoelectron spectroscopy) showed that the resulted plasma polymers containing —NH₂ and —CONH₂ was about 05 μm thick. The proton perm selectivity of plasma modified Nafion^TMmembrane was expressed by t_Cu, the transference number of the Cu ²⁺ ion through the membrane which was determined by using Nafion^TMmembrane as the separator in a typical two compartment cell(025 mol/L CuCl₂0 5mol/L HCl ｜plasma modified Nafion^TMmembrane｜1 mol/L HCl). Pretreatment of the Nafion^TMmembrane by oxygen sputtering enhanced the adhesion of plasma polymer onto its surface. The plasma treated membrane exhibited a high perm selectivity and its resistance in₁ mol/L HCl was only a little bit higher than Nafion^TMmembrane(<0.5 Ω·cm²).

Monolayer and LB Films of Ru(dpphen)₃²⁺ and Arachidic Acid Mixture

LÜ Wei-Xing, GUO Wei-Hua, FANG Kun, HE Ping-Sheng

2001, 22(4):  691-694. 

Asbtract ( )   PDF (217KB) ( )  

Related Articles | Metrics

The mixed monolayers of Ru(dpphen)₃²⁺ (dpphen=4,7-diphenyl-1,10-phenanthroline)[abbreviated as Ru(Ⅱ)] and arachidic acid(AA) in different molar proportions on pure water interface had been studied. The miscibility, molecular interaction of the two components and structure of condensed mixed momolayers were investigated in details. The monolayers were successfully transferred onto solid substrate and form functional mixed LBfilms. Characterized by optical spectra and low angle X-ray diffraction, the mixed LBfilms, which have strong absorption and emission in visible region, are regular, homogenous and have a good multilayer structure.

The Preparation and Property Studies of Transparent Resins Containing Rare Earth Terbium(Ⅲ) Complex

WANG Dong-Mei, LIN Quan, FU Lian-She, LI Huan-Rong, CHU Zhen-Xing, YANG Bai

2001, 22(4):  695-697. 

Asbtract ( )   PDF (410KB) ( )  

Related Articles | Metrics

The binary and ternary rare earth terbium(Ⅲ) complexes were introduced into the styrene/ α methylacrylic acid copolymerization system, and some optical resins that possess a high transparency in visible light region were obtained. The study of the optical property showed that they have good luminescent properties such as a high luminous intensity and a long luminous lifetime. In addition, we investigated the relationship among the transparency, the luminescent property of the copolymer, and the content of the components in the polymeric system. The results indicated that the optical resins can provide a relatively stable environment for composite rare earth complexes, which is good to exhibit the luminescent properties of rare earth complexes. At the same time, the rare earth complexes can offer the transparent resin a novel function.

Preparation and Photoelectric Properties of Oligo-Phenylene Vinylene/SiO₂ Composite film

TANG Jun, CAO Ya-An, WANG Ying, XIE Teng-Feng, WANG De-Jun, YANG Bai

2001, 22(4):  698-699. 

Asbtract ( )   PDF (128KB) ( )  

Related Articles | Metrics

The oligo phenylene vinylene(oligo-PV)/SiO₂ composite film was prepared by the sol-gel process. The surface photovoltage spectroscopy(SPS) and electric field induced surface photovoltage spectroscopy(EFISPS) had been used to investigate the charge transport process in olige-PV/SiO₂ heterostructured composite. The results show that the oligo-PV / SiO₂ composite film not only can improve the stability of oligo PV, but also have some photoelectric activity.

In-situ Formation of Nanoparticals in Polyurethane Microspheres

WANG Wu-Sheng, PAN Cai-Yuan, ZENG Jun, RUAN De-Li, ZHONG Feng

2001, 22(4):  700-702. 

Asbtract ( )   PDF (314KB) ( )  

Related Articles | Metrics

Linear or cross linked aqueous polyurethane dispersions with carboxyl Ag salt were prepared. TEMphotos show that Ag⁺ was homogeneously distributed in the microspheres. The Ag⁺ was reduced in situ by photochemical method. For linear polyurethane particles, as the extent of the reduction reaction of silver ions increased, the silver particles grew larger, but the number of the silver particles kept almost constant. In crosslinked polymer system, the number of silver particles increased, but the size of silver particles remained almost the same. We concluded that nucleation and growth of the silver particle are the result of the silver atom movement in the polymer matrix. In the linear polymer system, the movement of silver atom and aggregation of silver particles result in the formation and growth of several silver particles; in the cross linked polymer system, the polymer chain prevents the movement of silver particles, resulting in a number increase of silver particles.

Investigation on Aqueous Solution Properties of Dendrimer PPI

XU Min, YAN Xiao-Hu, YU Xue-Hai

2001, 22(4):  703-705. 

Asbtract ( )   PDF (162KB) ( )  

Related Articles | Metrics

Aqueous solution properties of dendrimer PPI[Poly(propylene imine)] were studied by measuring viscosity parameters. Particularly on the extremely dilute concentration region were focused on. The adsorption constant k, critical concentration c_{a, intrinsic viscosity[ η ], intermolecular association constant Km and hydrodynamic contact concentration c s were calculated. And the generation number dependence of these parameters were also studied. From the results, the unique behavior of dendrimer solution was explained preliminary. The adsorption phenomenon of polymer solution is general, and the adsorption theory is also fit for dendrimers. Furthermore, the dynamic contact concentration c s was determined by a simple viscosity method for the first time.}

A Direct Regioselective Synthesis of 6-Azido-6-deoxy-curdlan

BORJHAN Gereltu, HU Ri-Cha, LIU Guo-Guang, ZHONG Gui-Yun

2001, 22(4):  706-708. 

Asbtract ( )   PDF (169KB) ( )  

Related Articles | Metrics

6-Azido-6-deoxy-curdlan(ADC) was synthesized by a direct regioselective reaction of curdlan with triphenylphosphine, carbon tetrabromide and sodium azide(NaN₃) in DMFat room temperature. The structure of ADCwas determined by ¹³C NMR, IRand elemental analysis.

PAMAM Dendritic Titanium Tetrachloride Complexes and Their Catalytic Reactivity

WANG Jin-Feng, JIA Xin-Ru, JIN Zhong, ZHANG Wei-Cheng, FAN Yu, LI Ming-Qian, Wei-Yan

2001, 22(4):  709-711. 

Asbtract ( )   PDF (464KB) ( )  

Related Articles | Metrics

The modification of PAMAM( G=30) dendrimers was achieved by using aldehyde, benzyl chloride and trityl chloride as reaction agents, respectively. The complexes were synthesized simply by dropping TiCl₄ solution into the modified PAMAMdendrimers that were dissolved in certain solvent. The quantity of Ti contained in the complexes increased as the adding amount of TiCl₄ was increased. The polymerization of α methyl styrene catalyzed by the complexes was accomplished and it has shown that the complexes possessed catalytic function.