STUDY OF THE REACTION MECHANISM OF CYCLOHEXENE HYDROGENATION CATALYZED BY RhCl(PPh_3)_3

The hydrogenation rate of styrene in benzene using RhCI(PPh_3)_3 as catalyst increases with the concentration of styrene. But the hydrogenation rate of cyclohexene is rather different, It shows a maximum. So we inquire into the reaction mechanism of cyclohexene hydrogenation catalyzed by RhCI(PPh_3)_3. The rate of hydrogenation was measured at 25±0.15℃, as a function. of catalyst concentration, olefin concentration, triphenylphosphine concentration and hydrogen pressure. The maximum of the reaction rate is interpreted by the formation of RhClL_2S_2. The rate determining step is considered to be the reaction of olefin insertion into one of the Rh-H bonds formed by hydrogenation of RhClL3 to H_2RhClL_3. The hydrogenation rate of the substrate can be described by a third order equation in terms of concentration of H_2RhClL_3. Average error between the results evaluated by this equation and experimental results is about 4.9％. The quantum chemistry calculation gives support to the present mechanism.     

STUDIES ON DERIVATIVES OF 2, 3-DIHYDRO-4 H-1, 3, 2-BENZOXAZAPHOSPHORINE——THE DETERMINATION OF THE CRYSTAL AND MOLECULAR STRUCTURE OF 2, 3-DISUBSTITUTED-2, 3-DIHYDRO-4H-1, 3, 2-BENZOXAZAPHOSPHORIN-4-ONE (THION)-2-SULFIDE(OXIDE)

The two crystal structures of C_(17)H_(17),N_2O_2Cl_2PS (NP-8) and C_(17)H_(19)N_2O_2PS (NP-10-Ⅱ) have beendetermined by Patterson method. The crystals belong to monoclinic system with space group of P2_1/aand P2_1/n respectively. There are four molecules in the unit cell. Cell parameters: a = 26.622 (7)A, b = 7.711 (2) A., c = 9.461 (3) A, β = 94.90°(4) and a = 18.879(3) A, b = 10.199 (13) A, c = 8.948(3) A, β= 94.30°(3) for the two cells. After refinement by block diagonal matrix least squares me-thod, R factors are 0.046 for 2971 reflections of NP-8 and 0.076 for 1711 reflections of NP-10-Ⅱ. Referring to molecular structures of NP-8 and NP-10-Ⅱ spectra data have been satisfactorilycxplained. The characteristic features of the structures have been discussed.     

THE CRYSTAL STRUCTURE OF THE ADDITION COMPOUND OF DECAVANADIC ACID AND 5,7-DIMETHYL-2, 3-DIHYDRO-1, 4-DIAZEPINIUM

The title compound crystallizes in the space group C_(2h)~5-P2_1/n with unit cell constantsa=10.938 A, b=19.189 A, c=13.384 A and β=105.09°. Intensities of 4022 independent reflec-tions were collected with four-circle diffractometer using MoKa radiation. After reduction fordiffractometer data, we derived first the position parameters of all the V atoms by directmethod using SHELXTL program. The coordinates of all the non-hydrogen and hydrogenatoms were obtained from successive Fourier and difference sytheses. The block-diagonalleast-squares refinement for all atoms gave a final discrepancy weighted factor R_w=0.050. The result of structure analysis shows that four protons of each decavanadic acid arecaptured by the nitrogen atoms involved in the azepine molecules which are condensation pro-ducts of ethylenediamine with acetylaceton. In crystal, the isopoly-decavanadate anion, 7-member heterocyclic azepium and the crystal water are linked together by ionic forces andhydrogen bonding and the chemical content within a unit cell has been identified as 2[H_2V_(10)O_(28)]~(-4)·8[C_7N_2H_(13)]~( 1)·12H_2O.     

SYNTHESIS AND CHARACTERIZATION OF 2-(2-HYDROXY-3,5-DINITROPHENYLAZO)-7-(4-CHLORO-PHOSPHONPHENYLAZO)-1, 8-DIHYDROXY-NAPHTHALENE-3, 6-DISULF-ONIC ACID (CPAP) AS NEW REAGENT FOR DETERMINATION OF TOTAL PARE EARTHS

This paper reports the synthesis and general properties of the new reagent CPFP. Its dissociation constants have been determined. The characterization in determinating total RE with CPAP reagent has been investigated in detail. Analytic data for synthetic sample are satisfactory.     

4-(2-QUINOLYLAZO)-1, 3-DIHYDROXY-NAPHTHALENE——A NEW SENSITIVE ANALYTICAL REAGENT FOR TRACE COPPER DETERMINATION

The azo compound 4-(2-quinolylazo)-1,3-dihydroxynaphthalene (2-QADNm) has been synthesized and used as a new sensitive spectrophotometric and electroanalytical reagent for determination of trace amounts of copper. In dilute alkaline solutions, 2-QADNm shows a single-sweep polarographic wave at -0.95 V (vs. SCE). In the presence of copper(Ⅱ) two new waves appear at -0.52 and -0.79 V. Using the wave at-0.79 V, a trace amount of copper down to 10~(-8) mol/L can be determined. The electroanalytical characteristics of 2-QADNm and the electrochemical reaction mechanism of the copper(Ⅱ)-2-QADNm complex have been studied in detail by the use of various electrochemical techniques. In alkaline solutions, 2-QADNm forms red complex with copper(Ⅱ) which has an absorption peak at 526 nm, the molar absorptivity being 6.4×10~4 1·mol~(-1)·cm~(-1). In the presence of a non-ionic surfactant the molar absorptivity of this complex is 1.6×10~5 1·mol~(-1)·cm~(-1).     

A NEW METHOD FOR THE AROMATIZATION OF 18-METHYL-ESTRA-4(5), 9(10)-DIEN-3,17-DIONE

An aromatization reaction was found when 18--methyl--estra--4(5),9(10)--dien--3, 17--dione(6) was treated with triethyl orthoforrnate in dioxane in thepresence of catalytic amount of p--toluenesulfonic acid (TsOH), and 18--methyl--9(11)--dehydroestrone--3--ethyl ether (8) was obtained in 70% yield. The mechanism wasfound to be a process of etherification--oxidation reaction.     

CRYSTAL STRUCTURE OF 1-METHYL-6-(E-ETHOXYCAR-BONYLVINYL)-8-BENZOYL-2, 3-DIHYDRO-1H-IMIDAZO[1, 2-a] PYRIDIN-5-ONE

<正> The title compound C20H20N2O4(Mr=352.39)belongs to mono-clinic space group C2/c with a=9.208(4),b=11.714(3),c=32.336(8)A,β=100.83(2)°,V=7146.2(6)A3,Z=16,Dc=1.35 g/cm3,μ(Moka)=1.03 cm-1 and final R=0.06 for 1781 reflections with F≥2.5(F).There are two independent molecules in an asymmetric unit.Neither pyridinone nor phenyl ring is coplanar with the ketonic carbonyl group in the molecule.     

OXIDATION OF ALKYLBENZENES CATALYZED BY IRON( Ⅱ,Ⅲ)-1,10-PHENANTHROLINE AND 2, 2''''-BIPYRIDINE COMPLEXES

Oxidation of alkybenzenes PhCH_2R(R=H, CH_3, C_2H_5 and n-C_3H_7) under 1 atm. of O_2 or air catalyzed by iron(Ⅱ, Ⅲ)-2,2'-bipyridine and 1,10-phenanthroline complexes, affords the aryl-substituted ketones and alcohols with the conversion of 15.00％～34.58％ containing of 97.60％～99.80％ ketones and alcohols. The turnover numbers of these catalysts are over 3500 mol-cat. ~(-1)for 3.5 h.     

COPOLYMERIZATION OF BUTADIENE AND ISOPRENE CATALYZED BY V(acac)_3-Al(i-Bu)_2Cl-Al_2Et_3Cl_3 CATALYST AND CHARACTERIZATION OF THE PRODUCTS

Copolymerization of butadiene and isoprene catalyzed by the catalyst system V(acac)_3-Al(i-Bu)_2Cl-Al_2Et_3Cl_3 has been studied. Composition, microstructure, crystallinity and melting point of the copolymer obtained were determined by PGC, IR, X-ray diffraction and DSC methods respectively. The results revealed that the product was a copolymer and not a blend. The butadiene units presented in the copolymer were of trans-1,4-configuration, while the isoprene units were of both trans-1,4-and 3,4-forms. The melting point and crystallinity of the copolymer decrcascd with increase of molar ratio of isoprene to hutadiene.     

THE DISMUTATION OF SUPEROXIDE ANION BY COPPER(Ⅱ)COMPLEX OF 1,4,7,10-TETRAAZACYCLOTRIDECANE-11,13-DIONE—A KINETIC STUDY BY MEANS OF PULSE RADIOLYSIS

The dismutation kinetics of superoxide anion by copper complex of 1,4,7,10-tetranza-cyctotridecane-11,13-dione was studied by pulse radiolysis.The dismutation rate constants atvarious pH and concentration of complex were obtained.     

THE EFFECT AND FUNCTION OF AliBu_2OR'''' ON BUTADIENE-PROPYLENE ALTERNATING COPOLYMERIZATION CATALYZED BY VO(OR)_2Cl-AIiBu_3 SYSTEM

Four kinds of AliBu_2OB' with different R' were synthesized. The effect of AliBu_2OR'/AliBu_3 mole ratio on the conversion, the [η] of copolymer and catalytic efficiency were studied. The conversion was increased obviously and the catalytic efficiency was 2.7 times higher than before. The effect of the amount of AliBu_2OR' on the valence state of vanadium ion and the change of the valence state of vanadium ion with reaction temperature and time were studied. The VIS and IR spectra of the trinary-component catalyst system were measured. The model of active center including AliBu_2OR' was proposed. The function of AliBu_2OB was explained.     

BIS-PER(POLY)FLUOROALKYLATION OF PARA-SUBSTITUTED PHENOLS BY R_FI/Na_2S_2O_4 REAGENT SYSTEM

ＢＩＳ－ＰＥＲ（ＰＯＬＹ）ＦＬＵＯＲＯＡＬＫＹＬＡＴＩＯＮＯＦＰＡＲＡ－ＳＵＢＳＴＩＴＵＴＥＤＰＨＥＮＯＬＳＢＹＲ_ＦＩ／Ｎａ_２Ｓ_２Ｏ_４ＲＥＡＧＥＮＴＳＹＳＴＥＭ￥ＷｅｉＹｕａｎＨｕａｎｇ；ＨｏｎｇＢｉｎＹｕ（ＳｈａｎｇｈａｉＩｎｓｔｉｔｕｔｅｏｆ...     

PREPARATION AND PROPERTIES OF THE NEW ORGANIC CONDUCTOR (BEDT-TTF)_3Cu_2Cl_4

ＰＲＥＰＡＲＡＴＩＯＮＡＮＤＰＲＯＰＥＲＴＩＥＳＯＦＴＨＥＮＥＷＯＲＧＡＮＩＣＣＯＮＤＵＣＴＯＲ（ＢＥＤＴ－ＴＴＦ）_３Ｃｕ_２Ｃｌ_４ＰｅｉＪｉＷＵ；ＸｕｅＹｏｎｇＹＡＮＧａｎｄＤａｏＢｅｎＺＨＵ（ＩｎｓｔｉｔｕｔｅｏｆＣｈｅｍｉｓｔｒｙ，Ａｃａｄｅ?..     

ELECTROCARBOXYLATION OF ORGANIC COMPOUNDS WITH CARBON DIOXIDE CATALYZED BY METALLOPORPHYRINS(Ⅱ)——ELECTROSYNTHESIS OF SOME ORGANIC COMPOUNDS WITH CO_2 CATALYZED BY CoTPP

The catalyzation of CoTPP for electrocarboxylation of alkyl halides, alkenes and ketones with CO_2 are studied. The electrocarboxylation of these organic compounds with CO_2 in the presenec of catalyst can occur at more positive potential than that of no catalyst. The products of electrocarboxylation were identified by UV, IR and GC-MS. The electrocarboxylation mechanisms of different organic compounds are discussed.     

KINETICS OF THE IRREVERSIBLE MODIFICATION OF ENZYME ACTIVITY IN A SYSTEM OF COUPLED ENZYME ASSAY (Ⅰ)——ONLY PRIMARY ENZYME MODIFIED BY REAGENT Y

Kinetic equations are derived for the substrate reaction during simultaneous irreversible modification of enzyme activity for systems using coupled enzyme assay. It has been shown that the method proposed previously by Tsou for determining the irreversible inhibition constants can also be used in the present situation. Moreover, the criteria proposed to distinguish between different inhibition types are also applicable.     

GRAFT POLYMERIZATION OF ACRYLAMIDE ONTO HOMOPOLYMER OF 5-METHYL-5-HEXEN-2, 4-DIONE INITIATED BY CERIC ION

The homopolymerization of 5-methyl-5-hexen-2, 4-dione (methacryloylacetone, MAA),a vinyl monomer having β-diketone group, was carried out in the presence of benzophe-none (BP)/N N-dimenthyl-4-toluidine (DMT) system. Graft polymerization of acrylamideinitiated by ceric ion onto the homopolymer film was investigated and the mechanism ofthe grafting reaction was proposed on the basis of ESR study. The grafted copolymer wascharacterized by means of grafting percentage, water absorption, XPS spectra and scanningelectron photomicrographs.     

STUDY ON THE FORMATIONAL MECHANISM OF THE NORTHERN YELLOW (HUANGHAI) SEA COLD WATER MASS(Ⅰ)——SOLUTION OF THE MODEL

A hydrodynamic-thermodynamic equation set was set up to reflect the formational mechanism and evolution of the Northern Yellow (Huanghai) Sea cold water mass (NYSCWM) and its density circulation. Appropriate mathematical physical models were established by using some physical postulations. An approximate analytic solution to expound the distributions of temperature and three-dimensional current velocity, which can be used to expound the formational mechanism of the NYSCWM and its density circulation is obtained by using the theory of boundary layer and perturbational analyses.     

STUDY ON ASYMMETRIC SYNTHESIS OF 19-NORSTEROIDS SYNTHESIS OF A NEW OPTICALLY ACTIVE SYNTHON, (2R, 3S)-( )-2-ETHYL-2-(3'-OXO-4'-ENE)-AMYL-3-ACETOXY-CYCLOPENTANONE

This paper reports the synthesis of a new optically active synthon 6 for the asymmetricsynthesis of 19-norsteroids. Symmetric trione 9 obtained by the reaction of γ-carbonyl sulfo-xide 12b with 2-cthyl-1, 3-cyclopetanedione 8, was reduced asymmetrically by Saccharomycescerevisiae to (2R,3S)-(-)-14 and subsequently transformed into (2R,3S)-( )-6 by a shortreaction sequence. The absolute configuration of the asymmetrical product, (2R, 3S)-(-)-14,was established by converting it into the known compound (2R, 3S)-( )-17.     

SYNTHESIS AND STRUCTURE OF ADDUCT OF 1, 9-DIHYDRO-8,9-DIPHENYL-1, 2, 4-TRIAZOLO [4, 3-d] 1, 2, 4-TRIAZINE-3, 5-DITHIONE WITH TRIETHYLAMINE

<正> C16H13N5S2· (C2H5)3N: Mr = 440. 64, monoclinic, space group C2/c with a = 18.956(7)(?), b = 12. 866(7)(?), c = 20. 830(9)(?) , β=115. 63(3)°; Z=8; V = 4580(7)(?)3; Dc = 1. 278gcm-3; F (000) = 1872, μ= 2. 423cm-1 (MoKa). Final R is 0. 069. C16H13N5S2is non-planar with two rings, a five-member and a six-member with conformations of envelope and twist boat forms respectively, and the two substituted phenyl groups are in equatorial and axial positions.     

SYNTHESIS OF 1 - (N - BENZYLOXYCARBONYLAMINO)ALKANEPHOSPHATES AND - PHOSPHINIC ACIDS CATALYZED BY A CATION EXCHANGE RESIN

An improved method is developed by using strongly acidic cation exchange resin(001×1, H+ form) as a catalyst for the synthesis of diphenyl 1 - (N - benzyloxycarbonyl - amino) alka-nephosphonates and 1 - (N - benzyloxycarbonylamino) alkanephenyl phosphinic acids in high yields.