STRUCTURE-REACTIVITY STUDIES ON THE EXTRACTION OF RARE EARTHS BY DIALKYL ISOPROPYLPHOSPHONATES

Dialkyl isopropylphosphonates with various alkyl groups are synthesized for the structure-reactivity studies on the extraction of rare earths. Steric effect of ligands on the extrac-tion behaviour of rare earth is well demonstrated due to the lanthanide contraction. Thethermodynamic functions of the extraction reaction are estimated and the influence of chem-ical structure of extractants is discussed. By the method of continuous variation as well asthe elementary analysis, the composition of the extracted species is deduced as Ln(NO_3)_3·3L.The structure of the coordination compound is further elucidated by IR and NMR spectra.The magnetic property and the differential thermal analysis of the complexes are also studied.     

THEORETICAL STUDIES ON THE CYCLOADDITION REACTION OF FLUOROKETENE WITH ETHYLIDENIMINE

ＴＨＥＯＲＥＴＩＣＡＬＳＴＵＤＩＥＳＯＮＴＨＥＣＹＣＬＯＡＤＤＩＴＩＯＮＲＥＡＣＴＩＯＮＯＦＦＬＵＯＲＯＫＥＴＥＮＥＷＩＴＨＥＴＨＹＬＩＤＥＮＩＭＩＮＥＴＨＥＯＲＥＴＩＣＡＬＳＴＵＤＩＥＳＯＮＴＨＥＣＹＣＬＯＡＤＤＩＴＩＯＮＲＥＡＣＴＩＯＮＯＦＦＬＵ...     

STUDIES ON THE EXCIMER FLUORESCENCE OF POLYPHENYL GLYCIDYL ETHER AND POLYNAPHTHYL GLYCIDYL ETHER

Polyphenyl glycidyl ether (PPGE) and polynaphthyl glycidyl ether (PNGE) have beensynthesized by cationic polymerization and their structures characterized by carbon 13 NMRand 1R, etc. The fluorescence spectra of PPGE, PNGE and their corresponding monomersPGE, NGE as model compounds have been studied. In dilute solutions at room temperature,only monomer fluorescence of the chromophore is observed. Comparison between the spectraobtained from dilute solutions, concentrated solutions and solid film shows that there is excimeremission when polymer chains in solution or in film are sufficiently close to each ocher.From the concentration dependence of the excimer emission, further evidence is obtained forthe existence of interchain excimer interaction in these polymers.     

STUDIES ON THE SYNTHESIS OF ISOSARCOPHYTOL-A

A precursor 9 of isosarcophytol-A(1)was prepared from(■)-farnesol(3)through 6 steps.Isosarcophytol-A(1),a cembrane-type diterpenoid,was first isolated fromustralian soft coral(Nephthea brassica)in 1982,and its structure was estab-shed as(1,3,7,11-all ■,13■)-cembra-1,3,7,11-tetraen-13-ol,an isomer ofarcophytol-A■.As far as we know,its bioactivity and synthesis have noteen reported yet.     

STUDIES ON COMPLEXES OF RARE EARTHS WITH CROWN ETHERS(Ⅳ)SYNTHESIS AND CHARACTERIZATION OF THE COMPLEXES OF RARE EARTH NITRATES WITH 4'-BROMO-5'-NITROBENZO-15-CROWN-5

Six new solid complexes of macrocyclic polyether ligand 4′-bromo-5′-nitrobenzo-15-crown-5(L)withUivalent rare earth nitrates having composition of RE(NO_3)_3·L·mCH_3CN·nH_2O(RE=L_a--Nd,m=n=0,RE=Sm,Bu,m=0.1,n=1,4)have been synthesized in acetonitrile or acetone.All the isolated complexes have been char-acterized by elementary analysis,IR and UV spectra,differential thermal and thermogravimetric analysis,X-ray powderdiffraction analysis,molar conductance and measurementa of solubility in some general solventa.It shows thatcoordination number of the rare earth cation in the complexes of La,Ce,Pr and Nd nitrate is eleven.     

THE STUDIES ON CHELATING FIBER—THE STUDIES ON THE AMIDOXIMATION OF POLYACRYLONITRILE FIBER

The amidoximation process of commercial polyacrylonitrile fiber was studied. The results showed that it is possible to prepare a chelating fiber, which present high adsorption capability to Au^3+ and reasonable mechanical property,by the amidoximation of PAN fiber,with the increase of reaction time or agent concentration,the coversion of CN group in PAN increases rapidly at first and then increases slowly.When the reaction temperature is higher than that at which the paracrystalline region in the fiber is destroyed, the conversion of CN group increases greatly,but the mechanical property of the fiber begins to be inferior.     

STUDIES ON THE SYNTHESES OF FAVELINES

ＳＴＵＤＩＥＳＯＮＴＨＥＳＹＮＴＨＥＳＥＳＯＦＦＡＶＥＬＩＮＥＳＧａｎｇＬＩＮ；ＸｕｅＣｈａｏＷＡＮＧａｎｄＸｉｎＦｕＰＡＮ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＮａｔｉｏｎａｌＬａｂｏｒａｔｏｒｙｏｆＡｐｐｌｉｅｄＯｒｇａｎｉｃＣｈｅｍｉｓ...     

THE STUDIES ON CHELATING FIBER -THE STUDIES ON THE AMIDOXIMATION OF POLYACRYLONITRILE FIBER

The amidoximation process of commercial polyacrylonitrile fiber was studied. The results showed that it is possible to prepare a chelating fiber, which present high adsorption capability to Au3+ and reasonable mechanical property, by the amidoximation of PAN fiber, with the increase of reaction time or agent concentration, the coversion of CN group in PAN increases rapidly at first and then increases slowly. When the reaction temperature is higher than that at which the paracrystalline region in the fiber is destroyed, the conversion of CN group increases greatly, but the mechanical property of the fiber begins to be inferior.     

THE RETICAL STUDIES ON THE THERMOLYSIS OF THIETANE

The mechanism of the thermolysis of thietane to form ethyleneand thioformaldehyde has been studied by using ab initio SCF MO methodat STO-3G* and 3-21G* level.It has been found that there are twopossible stepwise pathways.One is to break C-C bond firstly,while theother is to break C-S bond at first.The cleavage of C-S bond is pre-ferred over that of C-C bond.     

NMR AND INFRARED SPECTROSCOPIC STUDY ON THE INTERACTION OF RARE EARTH WITH L-METHIONIHE

Five solid complexes of rare earth with L-methionine have been prepared. The interaction of rare earth with the ligand has been studied by NMR and IR spectroscopy.     

STUDIES ON THE CONSTITUENTS OF THE ROOTS OF SCUTELLARIA PLANIPES

ＳＴＵＤＩＥＳＯＮＴＨＥＣＯＮＳＴＩＴＵＥＮＴＳＯＦＴＨＥＲＯＯＴＳＯＦＳＣＵＴＥＬＬＡＲＩＡＰＬＡＮＩＰＥＳ￥ＹｏｕｓＹｕＺＨａＮＧ；ＸｉａｎＬＩ；ＹｕｎＺｈｅｎＧＯＵ（ＳｈｅｎｒｅｎｇＰｈａｒｍａｃｅｕｔｉｃａｌＵｎｉｖｅｒｓｉｔｙ，Ｓｈｅｎａｎ...     

NMR STUDIES ON THE WEAK INTERACTION OF FOUR-MONONUCLEOTIDES WITH TRYPTAMIDE AND LEUCINAMIDE

NMR spectroscopy analysis was introduced to investigate the weak interaction of four 5'—mononucleotides with tryptamide and leucinamide. Assuming a 1∶1 complex formation, the association constants were determined by nonlinear regression analysis. The association affinity of 4 mononucleotides with tryptamide decreased in the order: G>A>C>U, indicating that purine bases stack more strongly with tryptamide than pyrimidine bases. But with leucinamide the affinity decreases in the order: G>C>A=U, suggesting an amino acid—anticodonic preferential interaction. The implication of the present data to the origin of genetic code was briefly discussed.     

IR STUDIES OF THE SIDE CHAIN ALKYLATION OF TOLUENE WITH METHANOL ON ZEOLITE CATALYSTS

Surface species resulting from the decomposition of methanol on Na—、K—、Rb—、Cs—、BCs—、KCs— and KBCs—X zeolite at 420℃,and the relationship between sur-face species and the side chain alkylation selectivity from toluene with methanol have beenstudied by infrared and gas chromatographic methods.     

STUDIES ON THE REACTION OF d-ACETAMIDCCINNAMAMIDE WITH TRIS(DIETHYLAMINO)PHOSPHINE

d-Acetamidocinnamamide do not react with P(OMe)_3, with P(NEt_2)_3 they give rise to 2-methyl-4-hydroxy-5-d-[bis(diethylamino)phosphoryl] benzyl imidazole.The pathway is studied for the formation of Ⅰ. The two intermediates(Ⅱ) are isolated.The structures of Ⅰ and Ⅱ are confirmed by IR, ~1H NMR, ~(31)P NMR, Ms.     

STUDIES ON FLUORESCENCE SPECTRA OF SAMARIUM EUROPIUM TERBIUM AND DYSPROSIUM WITH BENZOYL UREA DERIVATIVES AND PHENANTHROLINE

Rare earth chelates of benzoyl urea derivatives were prepared in ethanol and fluorescence spectra of these chelates were studied in detail. A composition of [RE(BU)_3Phen] (NO_3)_3 was obtained. Correlation between chemical properties of ligands, chelates and spectroscopy was discussed. Intramolecular energy transfer in rare earth chelates was explained.     

STUDIES ON THE REACTION OF ORGANOTELLURONIUM SALTS

The structural studies of the telluronium saltrformation betweendibutyl telluride and secondary (?)-bromo compounds and the use of the obtai-ned salts for the olefination of carbonyl compounds were reported.     

INVESTIGATION ON THE INTERACTION OF METHANE WITH MgO SURFACE BY FT－IR SPECTROSCOPY

ＩＮＶＥＳＴＩＧＡＴＩＯＮ　ＯＮ　ＴＨＥ　ＩＮＴＥＲＡＣＴＩＯＮ　ＯＦ　ＭＥＴＨＡＮＥ　ＷＩＴＨ　ＭｇＯ　ＳＵＲＦＡＣＥ　ＢＹ　ＦＴ－ＩＲ　ＳＰＥＣＴＲＯＳＣＯＰＹＣｈｅｎ，Ｌａｉ－ｙｕａｎ；Ｌｉｎ，Ｌｉ－ｗｕ；Ｘｉｎ，Ｑｉｎ；Ｙｉｎｇ，Ｐｉｎ－ｌｉ...     

STUDIES ON THE POLAROGRAPHIC ADSORPTIVE COMPLEX WAVE OF RARE EARTH-ERIOCHROME AZUROL B (Ⅰ)

The polarographic behaviour of eriochrome azurol B (ECAB), one of complexing agentsof rare earths (RE), has been studied by several electrochemical techniques. The results showedthat the first step of one-electron reduction is reversible and the second step is irreversible, thatpart of the radical formed after the first electron transfer dimerizes, and that the cathodic andanodic peaks of ECAB at low concentration are adsorptive ones. The rate constant of dime-rization and some parameters related to adsorption of ECAB such as surface concentration,adsorption isotherm, free energy of adsorption and coverage of surface weIe calculated. The polarographic properties of RE-ECAB complexes and the reduction mechanism will bereported in the following paper (Ⅱ).