DETERM INATION OF THE STABILITY CONSTANTS OF COMPLEXES OF HISTIDINE,SOME DIPEPTIDES AND TRIGLYCINE WITH Zn(Ⅱ)AND Cd(Ⅱ)USING SMALL-SCALE PH-METRIC TITRATIONS

A potentiometric study on the complexes of His,Gly-His,ALa-His,Gly-Gly andGly—Gly—Gly with Zn(Ⅱ)and Cd(Ⅱ)has been reported.Small-scale potentiometric titrations were car-ried out to determine stabil ity constants of complexes at 25℃ with I=0.10 mol dm~(-3)(KNO_3).The com-puter programs SUPERQUAD were applied for data treatment with satisfactory results.     

ESR SPECTRA OF VO(NCS)_n~((2-n) ) COMPLEXES AND DETERMINATION OF THEIR STABILITY CONSTANTS

The ESR spectra of VO(NCS)_n~((2-n) ) complexes have been studied in this paper. It is shown that four complexes ions of various compositions, VO(NCS)~ , VO(NCS)_2, VO(NCS)_3~- and VO(NCS)_4~(2-), are formed in glyeol-water-mixed media. The parameters of the ESR spectra have been determined. We established a linear correlation between the hyperfine coupling constant and the coordination number n. n=117.66-3.41n (gauss). All the stability constants for various complexes formulated as VO(NCS)_n~((2-n) )(n=1,2,3,4) have been calculated from the ESR spectra, log K_1=2.15; log K_2=1.55; log K_3=0.87; log K_4=0.22. K_3and K_4 have not been reported in literature up to now.     

2HYDROXYETHYLATION OF L- AMINO ACIDS WITH CHLOROHYDRIN:SYNTHESIS OF L-N-2-HYDROXYETHYLAMINO ACIDS AND L- N,N- BIS(2-HYDROXYETHYL)AMINO ACIDS

Nineteen L-N-2-hydroxyethylamino acids and L-N,N-bis(2-hydroxyethyl)amino acids wereprepared from the reaction of chlorohydrin with L-alanine,L-valine,L-leucine,L-isoleucine,L-phenylalanine,L-serine,L-thrcunine,L-glutamic acid,L-aspartic acid and glycine.L-N,N,N',N'-tetra(2-hydroxyethyl)cystine was prepared by the reaction of L-cystine with chlorohydrin.     

DETERMINATION OF STABILITY CONSTANTS OF THE COORDINATION COMPOUNDS OF Au(Ⅲ)-2-MERCAPTOPYRIDINE-1-OXIDE AND METHYL DERIVATIVES——METHOD OF DUAL-WAVELENGTH CORRESPONDING SOLUTIONS

In this paper,we report the deductive formula used for the methodof dual-wavelength corresponding solutions under condition of having ligandinterference and the stability constants of three new coordination compounds[AuL_2]~+determined with this method.The stability of the three compounds,thenecessity of controlling pH in experimental systems and the advantage of thismethod are discussed in detail.     

STUDY AND APPLICATION OF SPECTROPHOTOMETRIC DETERMINATION OF MICRO AMOUNTS OF BISMUTH WITH MESO—TETRAKIS—(4—N—TRIMETHYL AMMONIUMPHENYL)PORPHINE

A new highly sensitive spectrophotometric method has been developed for the determination of micro amounts of bismuth (Ⅲ), based on the formation of Bi (Ⅲ)—meso—tetrakis—(4—N—trimethylammonium phenyl) porphine [T (4TMAP) P] complex. In the presence of Cd (Ⅱ), Bi(Ⅲ) reacts almost instantaneously with T (4TMAP)P in a 0. 6 mol/l NaAc—HAC buffer (PH5.8) at room temperature. The composition of the complex is T(4TMAP)P: Bi=1:1. The absorbance complex obeys Beer's law over the Bi(Ⅲ) concentration range 0.1—1.4 μg/ml. The linear relative coefficient γ is 0.9998. The apparent molar absorptivity was 1.75×10~5 1. mol~(-1). cm~(-1) at 463nm. The relative standard deviation of the method is 1.50％ for Bi(Ⅲ) 7ug/10ml (10 determinations). The interference of foreign ions has been examined. This simple and rapid method can be applied to the assay of Bi(Ⅲ) in some tablets directly.     

STUDIES ON THE VOLTAMMETRIC BEHAVIOR OF EU(Ⅲ)-ALDOPENTOSE AND EU(Ⅲ)-D-RIBOSE-L-AMINO ACIDS COMPLEXES

The rate of voltammetric reduction of Eu(Ⅲ)in acetate solutionwas increased by the formation of a complex with ribose,lyxose orarabinose.If a ternary complex of Eu(Ⅲ)-D-ribose-L-phenylanaline formed onthe surface of mercury electrode,the redox process of Eu(Ⅲ)became morereversible than that of Eu(Ⅲ)-D-ribose in solution phase.     

SYNTHESIS AND CHARACTERIZATION OF THE SOLID COMPLEXES OF Mn(Ⅱ), Co(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Ag(Ⅰ), Cd(Ⅱ) NITRATES WITH DISUBSTITUTED BENZO CROWN ETHERS

Nine new solid complexes of Mn(Ⅱ),Co(Ⅱ),Cu(Ⅱ),Zn(Ⅱ.),Ag(Ⅰ) nitrates with 4',5'-dibromobenzo-15—crown—5(L_A),Ag(Ⅰ),Cd(Ⅱ)nitrates with tetrabromodibenzo—18—crown—6(L_B)and Cu(Ⅱ), Ag(Ⅰ) nitrates with 4'—bromo—5'—nitrobenzo—15—crown-5(L_c),having the compositions of M(NO_2)_2·L·nH_2O(M=Mn,Co, Zn,L=L_A,n=2;M=Cu,L=L_A,n=1.5; M=Cd, L=L_B,n=0; M=Cu,L=Lc,n=2) and AgNO_·L·nCH_3CN(L=LA,n=0; L=L_B,n=1; L=Lc,n=1/2) have been synthesized in nonaqueous solvent. All the isolated complexes have been characterized by elementary analysis, IR and UV spectra, differential thermal and thermogravimetric analysis, X—ray powder diffraction analysis, molar conductance and measuremends of solubility in some general solvents.     

THE GROWTH OF SINGLE CRYSTAL AND THE DETERMINATION OF CRYSTALLOGRAPHIC PA RAMETERS OF (L-TRYPTOPHAN)~(A1)-INSULIN AND (D-TRYPTOPHAN)~(A1)-INSULIN

The crystal-growing conditions and the results of preliminary X-ray crystallographic analysis of (L-Try)~(A1)-insulin and (D-Try)~(A1)-insulin are reported. The single crystals of this pair of insulin analogue suitable for X-ray diffraction analysis have been grown in the citrate buffer system by still-setting method. They both belong to the trigonal system with space group R3. The parameters of the unit cell (L-Trp)~(A1)-insulin are αH= 80.31, cH= 37.45 and those of (D-Trp)~(A1)-insulin αH = 79.48, cH = 43.81. There are two molecules in an asymmetric unit. The obtained results are discussed.     

THE CRYSTAL STRUCTURE AND SPECTROSCOPIC PROPERTIES OF THE COMPLEXES FORMED BY TiCl_4 AND MgCl_2 WITH ESTERS——A RESEARCH ON THE STRUCTURE OF HIGHLY EFFICIENT CATALYSTS FOR POLYPROPYLENE

The complexes of TiCl_4, MgCl_2 and esters which are significant in industry have beenstudied by X-ray diffraction, IR and uv spectra. Their single crystal structures have also beendetermined. TiCl_4 and PhCOOEt can form two complexes, TiCl_4·L and TiCl_4·2L·MgGl_2, CH_3COOEtand H_2O form complex MgCl_2·2CH_3COOEt·2H_2O. All of them are molecular crystals. Theirspacial groups are C_(2h)~5-P2_1/c, C_(2h)~5-P2_1/n and C_(2h)~6-C_2/c respectively. From the XRD powderpattern, it has been ascertained that TiCl_4·L is formed in the process of the catalyst prepara-tion with milling-soaking method. Comparison between the IR spectra of the catalyst and Mgcomplex indicates that the coordinative bonds of the surface complex of the catalyst are verysimilar to that of the complex.     

MICROENVIRONMENTAL EFFECTS OF THE HELICAL CONFORMATIONS OF AMYLOSE AND ITS DERIVATIVES——THE FORMATION OF INCLUSION COMPLEXES WITH A SUBSTRATE BY AMYLOSE IN THE DMSO-H_2O MIXED-SOLVENT SYSTEM

The conformational behavior of amylose and the formation of helical inclusion complexesof amylose with a substrate, N-ethyl-4-hexadecyloxycarbonyl pyridinium iodide (1) -- asolvent-polarity probe, have been investigated in the DMSO--H_2O mixed-solvent system bymeans of surface tension, viscosity, UV, electrical conductance and ORD measurements. Thedecrease of the volume-fraction of DMSO, Φ_(DMSO) of the mixed-solvent system inducesconformational changes of the amylose from tight helices to loose and extended helicesinterrupted by short disordered regions. Such a transition is accompanied by abrupt changesof the viscosity and ORD curves. The mechanism of interaction between amylose and the substrate 1 also depends on thesolvent composition. When Φ_(DMSO) is larger than 0.70, the interaction of amylose with 1is apparently similar to those cases in which superhelices are formed between a macromo-lecule and some azo dyes; the latter are known to be bound exteriorly around the macro-molecular helices by oriented association. However, when Φ_(DMSO) begins to drop below0.70, the substrate molecules start to be bound in the helical cavities of the host and thussupramolecular inclusion complexes are formed. At Φ_(DMSO)<0.70, ORD shows a new nega-tive Cotton peak at a wavelength which coincides with the λ_(max) of 1 (276 nm). This implicatesinduced asymmetry for the achiral substrate 1 in a chiral microenvironment. Intrinsicdissociation constants (K_(d~*)) for the inclusion complexes can be obtained from the surface ten-sion- substrate concentration (σ-[1]) curves and the largest number of binding sites isfound to be below 30. The K_(d~*) values decrease with decreasing Φ_(DMSO), apparently inagreement with the results from conductance measurements. Presumably, the driving forcefor the transfer of the substrate molecules from the solvent-mixture bulk phase to the non-polar cavities of the host molecules comes from hydrophobic-lipophilic interactions.     

A RAPID FLUORIMETRIC DETERMINATION OF TYROSINE IN SERUM BY THE REACTION WITH CERIUM (Ⅳ)

A fluorimetric method for the determination of tyrosine in serum was proposed. The fluoriscence intensity is a linear function of tyrosine content in the range 0-1. 44ug/ml. The percentage of recovery was satisfactory.     

THE SYNTHESIS AND CHARACTERIZATION OF THE COORDINATION COMPOUNDS OF Pt(Ⅱ)AND Ir(Ⅲ)WITH 2-MERCAPTOPYRIDINE-1-OXIDE AND ITS METHYL DERIVATIVES

Six coordination compounds of Pt(Ⅱ)L_2 and Ir(Ⅲ)L_3 type(where L is PT~-,3Me-PT~-or 4Me-PT~-)are reported here.Four coordination compounds of the lattertwo ligands have never been reported before,while PT~-'s were synthesized withH_2PtCl_6 and(NH_4)_3IrCl_6 respectively,which were different from the methods ofDavidson et al.~1 and Sterinbrech~2.They were characterized by elemental analysis,UV,IR,~1HNMR and molar conductance.Their structural formulas have beendetermined,and the mechanism of synthetic reaction has been discussed.     

STUDIES ON THE NON－ISOTHERMAL KINETICS OF THERMAL DECOMPOSITIONS OF THE COMPLEXES OF Cd（II）WITH O－VANILLIN THIOSEMICARBAZONE AND IRON（III）WITH 2－［（O－HYDROXYBENZYLIDENE）AMINO］PHENOL AND PYRIDINE

ＳＴＵＤＩＥＳＯＮＴＨＥＮＯＮ－ＩＳＯＴＨＥＲＭＡＬＫＩＮＥＴＩＣＳＯＦＴＨＥＲＭＡＬＤＥＣＯＭＰＯＳＩＴＩＯＮＳＯＦＴＨＥＣＯＭＰＬＥＸＥＳＯＦＣｄ（ＩＩ）ＷＩＴＨＯ－ＶＡＮＩＬＬＩＮＴＨＩＯＳＥＭＩＣＡＲＢＡＺＯＮＥＡＮＤＩＲＯＮ（ＩＩＩ）ＷＩＴ...     

A NEW APPROACH TO THE SYNTHESES OF THE PHEROMONES OF JAPANESE BEETLE AND BONTEBOK WITH(Z)-VINYL CUPRATES

The dl-form of the sex pheromone of Japanese b(?)tle and the trail pheromone of Bontebok were synthesised in high purity of (Z)-olefinic configuration. The key step of the syntheses of compounds (1) and (2) involved stereospecific addition of n-alkyl cuprates to acetylene followed by addition of vinyl cuprates to aldehyde (7) and 3-buten--2-one.     

APPLICATIONS OF DSCPCF MODEL IN RARE EARTH COMPLEXES(Ⅴ)——ANALYSIS OF SPECTRA OF THE NEODYMIUM AND ERBIUM TETR A (2-THENOYLTRIFLUOROACETONE) MONO PIPERIDINE COMPLEXES

The complexes, Nd(TTA)_4·HP and Er(TTA)_4·HP, have been prepared, and their UV-VIS-NIR absorption spectra measured. The matrix element expressions with J=1/2—15/2 of f~3 and f~(11) configurations in D_4 symmetry field were derived with the Double Sphere Coordination Point Charge Field Model. And the influence of change in symmetry of the complex unit REO_8 on splitting of their levels was discussed. Based on theoretical calculations, the absorption peaks in the spectra were assigned.     

STUDIES OF RARE EARTH METAL COMPLEXES OF AMINO ACIDS AND PEPTIDES. SYNTHESES AND CRYSTAL STRUCTURES OF TRIAQUO TRIS (N-ACETYLGLYCINE) LANTHANIDE Ln(CH_3CONHCH_2COO)_3(H_2O)_3(Ln = Nd~(3+),Eu~(3+) and Er~(3+))

<正> The title complexes were synthesized and their crystal structures were determined. These complexes crystallize in trigonal space group R3 with 3 molecules in a unit cell and are isostructural to each other. Crystallographic data: complex 1, Nd(CH3CONHCH2COO)3(H2O)3, Mr = 546. 6, a= 16. 582(4), c = 5. 982(2)(?), V= 1424. 5(8)(?)3, Dc=1. 91gcm-3, F (000) = 819, μ = 28.06cm-1, R(Rw) = 0. 048(0. 061); complex 2, Eu (CH3CONHCH2COO)3 (H2O)3, Mr = 554.3, a = 16.564(10), c=5.974(3)(?), V = 1418(2)(?)3,Dc= 1. 95gcm-3, R (Rw) = 0. 018 (0. 025), F (000) = 828, μ= 33. 83cm-1; complex 3, Er-(CH3CONHCH2COO)3(H2O)3, Mr = 569. 6, a = 16. 476(7), c=5. 946(6)(?), V = 1398(2) (?)3, D, = 2. 03gcm-3, R (Rw ) = 0. 020 (0. 027) , F (000) = 843, μ= 46. 25cm-1. These complexes adopt mononuclear structure, in which Ln(Ⅲ) ion is coordinated to six oxygen atoms from three ligands and three oxygen atoms from water molecules with the polyhedron of 4,4,4-tricapped triangular prism. The carboxy-lato group of the ligand bonds to Ln     

SYNTHESIS OF POLYACRYLAMIDE WITH PENDANT POLY(BUTYL ACRYLATE) CHAINS USING THE MACROMER TECHNIQUE AND STUDIES ON THEIR PROPERTIES

INTRODUCTIONSince Milkovich and Chiang[1] developed a method of preparing copolymers with uniform side chains by usingthe macromer technique, the synthesis of copolymers with uniform side chains from different macromers hasbeen studied extensively. Milkovich et al. reported the synthesis of polystyrene macromer through termination ofliving polystyrene anions with methacryloyl chloride and its copolymerization with butyl acrylate to formthermoplastic elastomer[2]. Rempp[3] obtained polyoxy…     

THE STRUCTURAL CHEMISTRY OF PRASEODYMIUM COMPLEXES OF AMINO ACIDS I. THE CRYSTAL STRUCTURE OF COMPLEX {[Pr(Gly)_3(H_2O)_2]_2(ClO_4)_65H_2O

<正> Introduction. The title compound has been synthesized and its crystal struture determined by X-ray analysis. The crystal structure of this type of complex was reported for the first time, as far as we know.     

A NEW METHOD OF PREPARATION OF IRON(II) PORPHYRIN COMPLEXES — ISOLATION AND CHARACTERIZATION OF BIS(N-BUTYLAMINE) IRON(II) PORPHYRIN

Abstract

Fe(II)T(p-X)PP(NH₂Bu ⁿ )₂ (X = H, Cl, CH₃, OCH₃, TPP = dianion of meso-tetraphenylporphyrin) complexes have been prepared by the reduction of Fe(III) porphrins with n-butylamine in antiformin/dichloromethane in air, and by sodium borohydride reduction. The complexes were characterized by electronic and IR spectra and elemental analysis.     

STUDIES ON THE ELECTROANALYTICAL CHEMISTRY OF RARE EARTHS——THE ADSORPTIVE-COMPLEX WAVE OF THE COMPLEXES OF N, N'-DI-(2-HYDROXY-5-SULPHOPHENYL)-C-CYANFORMAZAN (DSPCF) AND LIGHT RARE EARTH ELEMENTS

The sensitive adsorptive-complex wave of the complexes formed by light rare earth elements and DSPCF is studied in this paper. The electroactivities of the complexes of light (La-Eu) and heavy rare earth elements (Gd-Lu), are quite different, so we can determine a certain light rare earth element or the total amounts of light rare earths without separating them from heavy rare earths. The mechanism of the adsorptive-complex wave and the reason why heavy rare earths could not form the electroactive complexes have been studied as well.