Chem. J. Chinese Universities

PURIFICATION OF RARE EARTH COMPOUNDS BY THE CHROMATOGRAPHIC ADSORPTION ACCOMPANIED WITH COMPLEX-FORMATION

Huang Zhupo, Guo Fengyu, Hou Pincheng

1981, 2(4): 401-408.

Asbtract ( )

PDF (505KB) ( )

Related Articles | Metrics

A method of chromatographic adsorption accompanied with complex-formation was developed for purifying rare earth salts from heavy metal impurities. This method provides a means to remove the following heavy metal impurities from rare earth salts to an extent of ppm level: Fe<0.57, Cu<0.5, Co<0.2, Ni<1.0 and Pb<0.2, by simply passing the solution through a chromatographic column made up of blended active charcoal and complexing agent. This method enables purification to be accomplished with a higher efficiency and in a larger capacity than other methods. The efficiency of different complexing agents and the optimum conditions have been studied. A possible reaction mechanism in the chromatographic column has been suggested as follows: 1/3Fe³⁺ (ι) + QH(s) = QFe_1/3 (s)+H+(ι).

SYNTHESIS AND CRYSTAL STRUCTURE OF LANTHANUM HYDROXIDE BROMIDE

Zhong Xinghou, Sun Jutang, Jiang Changwu, He Xiqing, Du Xiuzhen, Li Ningxian, Xu Lianfa

1981, 2(4): 409-416.

Asbtract ( )

PDF (527KB) ( )

Related Articles | Metrics

The lanthanum hydroxide bromide,La(OH)₂Br, has been synthesised by the reaction of lanthanum oxybromide with water vapor under ordinary temperature and pressure.

DETERMINATION OF STABILITY CONSTANTS OF MIXED LIGAND COMPLEXES OF RARE EARTHS BY METHOD OF TWO-PHASE TITRATIONS

Gao Hongcheng, Chen Dian, Wu Jinguang, Xu Guangxian

1981, 2(4): 417-422.

Asbtract ( )

PDF (372KB) ( )

Related Articles | Metrics

In the present investigation, we have extended the method of two-phase titrations to the determination of stability constants of mixed ligand complexes of the following type.

THE REACTION OF cis-[Pt(NH₃)₂Cl₂] ON NUCLEOSIDES

Tang Wenxia, Zhang Caifen, Tai An-pang

1981, 2(4): 423-430.

Asbtract ( )

PDF (481KB) ( )

Related Articles | Metrics

The interaction of cis-[Pt(NH₃)₂Cl₂] with guanosine, adenosine, cyti-dine and thymidine, as constituents of DNA, was studied spectrophotome-trically at pH5.5,37°C in the presence of 0.1M NaClO₄. It was found that the first three nucleosides formed 1:1 and 1:2 complexes with cis-CptⅡ (NH₃)₂], whose apparent stability constants and initial rate of formation are given as follows:Thymidine showed no interaction with cis-[PtⅡ (NH₃)₂].On the basis of the above findings, a possible mode of reaction of cis-[Pt(NH₃)₂Cl₂] with DNA in the cancer cells is discussed. Thermodynami-cally and kinetically, it is considered most probable that cross links were formed between cis-[PtⅡ (NH₃)₂] and nucleosides in DNA, e. g.,guanosine,and it seems unlikely that a chelate was formed withany one nucleoside, e. g.,

THE SOLVENT EXTRACTION OF SEVERAL LANTHANIDE RADIONUCLIDES WITH 4-METHYLBENZO-15-CROWN-5

Wang Wenji, Chen Bozhong, Jin Zhonggao, Wang Ailing

1981, 2(4): 431-437.

Asbtract ( )

PDF (493KB) ( )

Related Articles | Metrics

The solvent extraction of several lanthanide radionuclides(¹⁴⁴Ce, ¹⁴⁷Nd, ^152+154Eu,¹⁷⁰Tm and ¹⁶⁹Yb) from aqueous picric acid solutions with 4-methyl-benzo-15-crown-5 in chloroform has been investigated. The extracted species are found to be 1:2:3 (metal/crown/picrate) complex from slope analysis. The extraction equilibrium constants (K_ex) have been determined at 25°C. The order of K_ex values for trivalent lanthanide is Nd³⁺>Eu³⁺> Ce³⁺ >Tm³⁺ >Yb³⁺. This indicates that the ionic size of Nd³⁺(r = 0.995Å) may better match the cavity size of 4-methylbenzo-15-crown-5 than the ionic sizes of other lanthanides.In order to compare lanthanides with actinides, the extractability of 4-methylbenzo-15-crown-5 for Th⁴⁺, UO₂²⁺ and Am³⁺ has been determined.

THE ANALYSIS OF ANTI-MOISTURE GRANULE OF VITAMIN U BY MEANS OF DUAL-WAVELENGTH TLC SCANNER

Zhao Tihui, Chen Yuying, Zhang Ji, Qian Junbin, Yu Jialin, Shan Wendian

1981, 2(4): 438-444.

Asbtract ( )

PDF (436KB) ( )

Related Articles | Metrics

Vitamin U is a commonly used combined drug for treatment of ulcer of digestive nature. Its chemical name is [(3-Amino-3-carboxypropyl)dimethyl sulfomium chloride].In this paper we have used the paper chromatography with N-butanol-95% ethanol-formic acid-water (77:15:20:20) as developing agent. We have separated and identified anti-moisture granule of vitamin U,and determined Rf value of each component.After separation of vitamin U from its decomposition products, serine, glycine etc., we availed ourselves of the dual-wavelength TLC scanner connected with the processor, and used external comparison method and relative percentage quantitative method to determine the content.This method has proved to be accurate, sensitive and simple in operation.

SIMULTANEOUS ANODIC DIFFERENTIAL PULSE VOLTAMMETRIC DETERMINATION OF GUANINE AND ADENINE OF DEOXYRIBONUELEIC ACID (DNA)

Deng Jiaqi, Chen Xiaoming, He Peixin

1981, 2(4): 445-449.

Asbtract ( )

PDF (496KB) ( )

Related Articles | Metrics

This paper reports that the micro amount of guanine and adenine in DNA can be determined simultaneously by anodic differential pulse voltam-metric method and so a rapid determination of G + C/A + T value of DNA is established. The sensitivity of this method is about 100 times higher than the ultra-violet adsorption method, in which the purines are seperated by paper chromotography. The time required for once determination is only1(1/2)hr.We use the DNA of calfthmos as the standard sample in the experiment and the result shows that this method is accurate. The G + C/A + T values of six sorts of DNA of E. coli, heliothis armigera and so on are determined.

THE PREPARATION OF SOME N-MANNICH BASES OF 9,10-DIHYDROANTHRACENE-9, 10-ENDO-α,β-SUCCINIMIDE

Chen Guangxu, Zhong Weixiong

1981, 2(4): 450-454.

Asbtract ( )

PDF (420KB) ( )

Related Articles | Metrics

9,10-Dihydroanthracene-9,10-endo-α,β-succinimide has been prepared by fusing 9,10-dihydroanthracene-9,10-endo-α,β-succinic anhydride with urea. The condensation between this compound and formaldehyde forms the N-methylol derivative. The N-methylol derivative condenses easily with various amines to yield N-Mannich bases of 9,10-dihydroanthracene-9,10-endo-α,β-succinimide. Eighteen such bases were prepared(Table 2). These results lend support to Zinner and Herbig's proposal that in Mannich reaction of this type, the NH-acid component condenses first with formaldehyde to yield the N-methylol derivative, which is then converted to the desired N-Mannich base by the reaction with the amino-component.

SYNTHESIS OF α-ALKYL-α-AMINO ACIDS

Ski Yaoceng, Sun Xiangzhen, Zhu Huixiang, Jiang Yanhao

1981, 2(4): 455-459.

Asbtract ( )

PDF (278KB) ( )

Related Articles | Metrics

a-Alkyl-a-amino acids were synthesized from ketones, chloroform and ammonia in the presence of potassium hydroxide, lithium chloride and phase transfer catalyst.

THE PHASE TRANSFER CATALYTIC ACTION OF POLYOXYETHYLENE SURFACTANTS IN PREPARING DICHLOROCARBENE

Tao Fcnggang, Xu Jigong

1981, 2(4): 460-462.

Asbtract ( )

PDF (225KB) ( )

Related Articles | Metrics

Polyoxyethylene surfactants can be used as phase transfer catalysts in preparing dichlorocarbene. Their catalytic power varies with the number of oxyethylene units in the molecule.

RESEARCH ON 2,6-DISUBSTITUTED BENZO-BISOXAZOLES-Ⅱ-THE HMO CALCULATION AND THE SUBSTITUTENT EFFECT ON THE SPECTRA OF 2,6-DIPHENYL-BENZO-BISOXAZOLES AND THEIR PARA-SUBSTITUTED DERIVATIVES

Cai Zunsheng, Lin Shaofan, Zhao Xuezhuang, Kao Chenheng

1981, 2(4): 463-470.

Asbtract ( )

PDF (530KB) ( )

Related Articles | Metrics

2,6-Diphenyl benzo-[l,2d;4,5d']-bisoxazoles,2,6-diphenyl benzo-[1,2d; 5,4d']-bisoxazoles,as well as some of their parasubstituted derivatives were treated with HMO method. The relevant π energy levels and molecular diagrams were obtained. The substituent effects on UV absorption spectra and FL emission spectra were analyzed and approached by some quantum chemistry methods on the basis of HMO theory.

RESEARCH ON 2,6-DISUBSTITUTED BENZO-BISOXAZOLES-Ⅲ-2,6-DISTYRYL BENZO-BISOXZOLES AND SOME OF THEIR DERIVATIVES

Kao Chen-heng, Zhou Yimin, Pan Jiaxing, Wang Mingzhen, Fan Xiuju

1981, 2(4): 471-476.

Asbtract ( )

PDF (477KB) ( )

Related Articles | Metrics

2, 6-Distyryl benzo-[l, 2d; 4, 5d']-bisoxazole and 2, 6-distyryl benzo-[l,2d;5, 4d']-bisoxazole as well as six derivatives of each of them were synthesized by condensation of the corresponding 2,6-dimethyl benzo-[l,2d; 4,5d']-bisoxazole or 2, 6-dimethyl benzo-[l,2d; 5, 4d']-bisoxazole respectively with benzaldehyde or substituted benzaldehydes in the presence of alkali. The m.p., λ_max of UV spectra and fluorescence emission spectra, as well as laser properties of the products are listed in tables.

THE STRUCTURAL EFFECT IN FORKED CONJUGATIVE SYSTEMS-Ⅱ-MOLECULAR ORBITAL ENERGY AND BOND ORDER

Chen Zhendong, Jiang Mingqian

1981, 2(4): 474-494.

Asbtract ( )

PDF (394KB) ( )

Related Articles | Metrics

In this paper the energies for the four highest occupied molecular orbitals E₁, E₂, E₃ and E₄, and the energy differences ΔE₁ between the HOMO and the LUMO for three types of forked conjugative polyenic compounds have been calculated by the HMO method. The three types of the forked conjugative systems dealt with in this paper have been designated as the amphi-direction-,the bifurcation-, and the concourse-type of compounds, and are exemplified by 2-vinyl-polyenes (A), α-methylene polyenic dicar-bonyl compounds (B), and vinyl polyenyl ketones(C), respectively.

STUDIES ON NITROXIDES-Ⅲ-AN MO CALCULATION OF 2,2,6,6-TETRAMETHYL-4-HYDROXYPIPERIDINE-1-OXYL FREE RADICAL

Liu Youcheng, Liu Zhongli, Wang Yukun

1981, 2(4): 477-483.

Asbtract ( )

PDF (805KB) ( )

Related Articles | Metrics

An EHMO calculation has been performed for 2,2,6,6-tetramethyl-4-hydroxypiperidine-l-oxyl(TMHPO). It is shown that the most stable conformation is the chair form with a 12° of “out of plane” angle between the C-N-C plane and the N-O bond, which is consistent with that obtained by X-ray diffraction. The colouration of the nitroxide and the spectroscopic bands of TMHPO in u. v.-visible spectrum may be explained by analyzing the MO levels. The spin density on the nitrogen atom is estimated to be 0.43, from which the ESR hyperfine splitting constant is calculated to be 10.8 G,which is in good accordance with the experimental value.

STUDY ON HEAT STABILITY OF THE SURFACE STRUCTURE OF SILICA GELS

Dai Minguang, Gao Yueying, Zhao Zhenguo, Gu Tiren

1981, 2(4): 495-502.

Asbtract ( )

PDF (547KB) ( )

Related Articles | Metrics

The effects of heat-treatment on the surface and pore structure of silica gels heated in the range of 200-1100°C have been studied. We have measured the specific surface area by means of B. E. T. nitrogen adsorption method, and the adsorption-desorption isotherms of ethyl alcohol at 25°C by gravimetric method. Moreover, we have calculated the pore volume and the pore-size distributions of silica gels. After heat-treated at 950°C, the specific surface area and pore volume of the purified silica gels are decreased only 25% and 21% respectively, while those of unpurified gels are decreased more than 95%. From these results, it is concluded that the effect of impu-rity is to decrease the thermal stability of silica gel. After heat-treated at various temperatures (200-1100°C), the purified silica gels are studied by infrared spectroscopy in the 2350-4000cm^-1 region (paraffin oil is used as mulling agent). The results show that the absorption bands at 3720cm^-1 (isolated single hydroxyls) are decreased slightly when the temperature is raised from 200 to 950°C, and disappear completely when the temperature is raised to 1100°C. However, the absorption bands in 3300-3600cm^-1 (associated hydroxyls) are decreased much more rapidly than band at 3720cm^-1. The x-ray diffraction shows that only the purified silica gel heated at 1100°C shows the diffraction lines of β-tridymite. When the heating temperature is lower than 950°C,the sintering and thus the decreasing of free hydroxyls are only gentle. However, as the heating temperature is reached to 1100°C,the surface area and pore volume of silica gel decrease markedly, This shows the sintering has occured vigorously, and thus the free hydroxyls may be eliminated almost completely. It is interested to note that after heated at 1100°C the purified silica gel still has quite large surface area of 95m²/g and pore volume of 0.15cm³/g.

ON THE RADIAL WAVE FUNCTION FOR THE FIRST-ROW TRANSITION METAL IONS IN THE CENTRE OF THE COMPLEX COMPOUND

Zhao Shangbo, Wang Huisu

1981, 2(4): 503-513.

Asbtract ( )

PDF (687KB) ( )

Related Articles | Metrics

Taking the effect of centre symmetric ligand field into account, we have proposed 3d-radial wave function which is in the bound state and consists of different bases. The crystalline spectra of some complex compound ions are calculated by using this wave function. If the suitable boundary conditions are considered, we can input a parameter and get the result in agreement with the experimental crystalline spectra. The essence of our method is that, on the base of the crystal field model for point charge, the effect of molecule orbit is considered partly for the centrally symmetric field of coordination bodies. This mix bases wave function which is suggested by us applies to all central transition metal ions of complexes which have suitable symmetry, If the interactions between the valence electrons of metal ion are omitted, this mix bases single electron 3d-radial wave function can be used to calculate molecular trajectory as well.

PROMOTION OF TUMOR INHIBITORY ACTIVITY STUDIES ON CORIOLAN BY CHEMICAL STRUCTURAL MODIFICATION

Zhang Yishen, Li Zhiping

1981, 2(4): 514-516.

Asbtract ( )

PDF (187KB) ( )

Related Articles | Metrics

Cleavage of the β(l-6) glucosidic linkage of cariolan by a method of selective oxidation, reduction and partial hydrolysis resulted in a significant promotion of its tumor inhibitory activity.It was found also that there was a decrease of tumor inhibitory activity of cariolan from natural source in the process of decolorization.

STUDY ON THE SYNTHESIS OF ZEOLITE ZSM-5

Li Hezuan, Xiang Shouhe, Wu Deming, Liu Yueting, Zhang Xiaosen, Liu Shuquan

1981, 2(4): 517-519.

Asbtract ( )

PDF (478KB) ( )

Related Articles | Metrics

A new method of synthesis of zeolite ZSM-5 is proposed. The zeolite ZSM-5 has been prepared from sodium silicate, aluminum sulfate and sulfuric acid in the absence of any alcohol, amine or other nitrogen containing compound. Its scanning electron micrographs, X-ray diffraction pattern and the results of adsorption tests are given in Fig. 1-2 and Table 1 respectively.

THE MECHANISM OF FORMATION AND CRYSTAL GROWTH OF MOLECULAR-SIEVE-ZEOLITE-Ⅱ-THE STUDY ON NUCLEATION OF MOLECULAR-SIEVE-ZEOLITE IN A LIQUID PHASE BY THE ELECTRON DIFFRACTION METHOD

Xu Ruren, Zhang Jianmin

1981, 2(4): 520-521.

Asbtract ( )

PDF (208KB) ( )

Related Articles | Metrics

The study on nucleation of molecular-Sieve-Zeolite is an important key to the investigation of the mechanism of formation and crystal growth of Molecular-Sieve-Zeolite. This is one of the problems to which Zeolite-Chemists pay close attention. But there is no efficient method so far. We applied broad line Na²³-NMR technique to investigate the existence and growth of nucleation center with Faujasite type structure in a colloidal system and obtained some satisfactory results if sizes of the nuclei were bigger. To look for new research means, we made use of electron diffraction method to detect and study the nuclei in a sol of aluminosilicates. An example was introduced here. It is proved that there are nuclei of NaX type Zeolites in a sol of Faujasite type "Directing-Agent" which ages in a short time. So the application of the electron diffraction method to investigate the nucleation of Zeolite in a liquid phase seems to be a new development.

STUDIES ON DIFLUORO [2,2] PARACYCLOPHANES-Ⅰ-PREPARATION OF DIFLUORO [2,2] PARACYCLOPHANE BY CATALYTIC PYROLYSIS

Tao Wentian, Huang Xiaoling, Kuang Fugui, Li Zaoying, Qu Fanqi

1981, 2(4): 522-524.

Asbtract ( )

PDF (193KB) ( )

Related Articles | Metrics

The title compound was prepared in 15% yield by the catalytic pyrolysis of 2-fluoro-p-xylene in the presence of platinum net at about 1000°C, with 1,2-dibromoethane as initiator.

SPECTROPHOTOMETRIC DETERMINATION OF TRACE AMOUNT OF TITANIUM WITH PHENYLFLUORONE IN THE PRESENCE OF NONIONIC SURFACTANT

Wang Shuren, Zhou Jingdao, Guo Zhu

1981, 2(4): 525-528.

Asbtract ( )

PDF (273KB) ( )

Related Articles | Metrics

THE QUANTITATIVE RELATIONSHIP BETWEEN THE ION-EXCHANGE EQUILIBRIUM CONSTANTS OF CATIONS IN NITRIC ACID AND THE ION-POTENTIAL

Fan Biwei, Liu Mancang, Hu Zhide

1981, 2(4): 529-532.

Asbtract ( )

PDF (243KB) ( )

Related Articles | Metrics