Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 52 , Issue 12
Showing 1-50 articles out of 71 articles from the selected issue
  • Noboru Tanaka
    1979 Volume 52 Issue 12 Pages 3477-3479
    Published: 1979
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A semi-empirical method recently proposed for the calculation of the potential energy surface of the H3 system is extended to a larger polyatomic H4 system. The energy formula is based on the valence-bond formulation and is expressed as functions of many multiple exchange integrals. These integrals can be decomposed into “diatomic” contributions by using the Mulliken approximation. The diatomic contributions are estimated from accurate values of the H2 molecule. Calculations of the H4 potential energy for the symmetric linear, linear equidistant, and square planar configurations are presented. The present method is of use for dynamical studies of the H2+D2 exchange reaction.
  • Hiroaki Ohya-Nishiguchi
    1979 Volume 52 Issue 12 Pages 3480-3483
    Published: 1979
    Released: April 19, 2006
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    Modifying a general theory of antiferromagnetism proposed by Oguchi, the parallel and perpendicular magnetic susceptibilities (χ⁄⁄ and χ respectively) of antiferromagnetically interacting spin-pair systems have been formulated. As the parameter of the equations, κ=z|J′|⁄|J| , approaches zero, both of them coincide with a familiar equation of isolated spin-pairs. In the 0<κ≤1 range the maximum susceptibility and the Weiss constant are compared with those estimated exactly by the alternating antiferromagnetic linear-chain model. For 1<κ≤2, they can be characterized by a broad maximum and a transition to the antiferromagnetically ordered state. For κ>2, χ⁄⁄ in and χ show curves similar to those of a typical three-dimensional antiferromagnet. The χ⁄⁄a and χ⊥a 2,2-diphenyl-1-picrylhydrazyl–benzene (1:1) complex have been examined based on the theoretical results for κ=1.3. The magnetic susceptibilities of the other organic free radicals have been compared with the results calculated in the 0≤κ<1 range.
  • Naohiko Mikami, Hwai-Kwan Hong
    1979 Volume 52 Issue 12 Pages 3484-3495
    Published: 1979
    Released: April 19, 2006
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    Polarized two-photon absorption spectra of naphthalene in a single crystal of durene were observed with one and two beams of tunable dye lasers. Diagonal elements of the two-photon transition tensor were determined by one beam experiments with different incident polarizations on different faces of an oriented single crystal. The off-diagonal elements of the two-photon transition tensor were determined with two synchronized beams of different wavelengths and polarizations on the same sample. It was found that most of the vibronic states have large σLL consistent with an overall vibronic Ag symmetry and a long axis polarized 1B2u intermediate state. The intermediate states of the two-photon process of the strongest vibronic origin have been discussed on the basis of the observed values of the two-photon transition tensor elements. The band also has a small but non-vanishing off-diagonal tensor element (σLM). A crystal field perturbation due to reduced site symmetry by a B3g two-photon allowed state is postulated.
  • Masaru Mitsuishi, Yuzoh Yamaguchi
    1979 Volume 52 Issue 12 Pages 3496-3498
    Published: 1979
    Released: April 19, 2006
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    The mean activity coefficients of Methyl Orange (MO), Ethyl Orange (EO), Propyl Orange (PO), and Butyl Orange (BO) in aqueous solutions ranging in concentration from 10−3 to 10−2 mol kg−1 have been determined by means of isopiestic measurements at 50 and 60 °C respectively. It has been found that the mean activity coefficients of MO being the largest, and those of BO, the smallest. The coefficients have been found to decrease with an increase in the dye concentration. The examination of the results by Milicéivic treatment suggests that MO, EO, and PO are present as a monomer or a dimer, while BO exists as a trimer at 60 °C.
  • Yoshinori Sugitani, Kenji Kato
    1979 Volume 52 Issue 12 Pages 3499-3502
    Published: 1979
    Released: April 19, 2006
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    A new method of estimating the absolute quantum efficiency of a phosphor material based on the simultaneous measurement of photoacoustic and fluorescent excitation spectra is presented. The method is distinguishable from previous methods in that a reference material is not required. The method has been successfully applied to uranium-mica compounds. The transition rate constants for the radiative and non-radiative processes have been obtained on the basis of the quantum efficiency and fluorescence life time data.
  • Yo-ichi Ishikawa, Ko-ichi Sugawara, Shin Sato
    1979 Volume 52 Issue 12 Pages 3503-3506
    Published: 1979
    Released: April 19, 2006
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    Pulse radiolysis has been combined with Lyman-α absorption spectroscopy for the measurement of absolute rate constants for the addition reactions of H and D-atoms to oxygen, nitrogen monoxide, acetylene-d0 and -d2, and 1,3-butadiene at room temperature. The rate constants obtained with O2 and NO were in good agreement with the results previously reported and no H/D isotope effect was found. With acetylenes and 1,3-butadiene, the following rate constants were obtained (units of cm3 molecule−1 s−1): (3.8±0.4)×10−13 for H+C2H2; (2.6±0.2)×10−13 for D+C2H2; (3.8±0.2)×10−13 for H+C2D2; (2.5±0.2)×10−13 for D+C2D2; (8.5±1.5)×10−12 for H+1,3-C4H6; (7.5±0.6)×10−12 for D+1,3-C4H6. These results are compared to previous studies, and the H/D isotope effect discussed.
  • Ko Saito, Teiji Yokubo, Tohru Fuse, Hiroyuki Tahara, Osamu Kondo, Tets ...
    1979 Volume 52 Issue 12 Pages 3507-3510
    Published: 1979
    Released: April 19, 2006
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    The thermal gas-phase decomposition of vinyl bromide in Ar has been studied behind reflected shock waves over the temperature range between 1300 and 2000 K and the density range of 5.2×10−6–3.8×10−5 mol cm−3 by monitoring the UV absorption of C2H3Br and the IR emission of HBr. The decomposition proceeds via the molecular elimination of HBr, and the unimolecular process is in the low-pressure region under the present experimental conditions. The low-pressure-limit rate constant was obtained as
    k2nd=1013.98±0.21exp{−(41.5±1.6 kcal mol−1)⁄RT} cm3 mol−1 s−1.
    The collision efficiency factor, βc, was obtained as about 2×10−4, considerably lower than that of vinyl chloride.
  • Seiji Sawamura, Yoshihiro Taniguchi, Keizo Suzuki
    1979 Volume 52 Issue 12 Pages 3511-3514
    Published: 1979
    Released: April 19, 2006
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    Absorption spectra of the CT band of I2 complexes were observed in several nonpolar solvents at 1 bar, and in heptane up to 4400 bar. All solvent shifts were red with an increase in (n2−1)/(2n2+1), the refractive index (n) function of solvents, consistent with the solvent shift theory. On the other hand pressure caused a variety of shifts, that is, red shifts in benzene–, toluene–, and mesitylene–I2 complexes, an inversion shift from red to blue in HMB–I2 complex, and blue shifts in Et3N–, n-Pr3N–, and n-Bu3N-I2 complexes, though increase in pressure invariably raises the (n2−1)(2n2+1) value of solvent. The pressure shifts of I2 complexes seem to be interpreted by a sum of two effects. One is the increased polarity of the solvent, which causes a red shift. The other is the decrease in the bond distance between a donor and an acceptor, which contributes to a blue shift in a strong CT complex and to a red shift in a week one. The pressure and solvent shifts of I2 complexes were compared with those of π-donor–TCNE complexes.
  • Hiroatsu Matsuura, Hiromu Murata
    1979 Volume 52 Issue 12 Pages 3515-3521
    Published: 1979
    Released: April 19, 2006
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    The molecular force field in terms of the local symmetry coordinates was determined for unbranched dialkyl selenides. Twenty-six important force constants associated with the selenium part were adjusted by using about two hundred observed vibrational wave numbers for a total of twelve conformational isomers of ethyl methyl selenide, diethyl selenide, methyl propyl selenide, butyl methyl selenide, and ethyl propyl selenide. Remaining force constants of the selenides were assumed to be equivalent to those for unbranched dialkyl sulfides and alkanes. The least-squares calculation gave an overall root-mean-square deviation of 6.7 cm−1 between the observed and calculated wave numbers. The force constants and the results of the normal coordinate treatment are given in this paper.
  • Hatsue Tamura, Kazuhide Ogawa, Akira Takeuchi, Shoichiro Yamada
    1979 Volume 52 Issue 12 Pages 3522-3527
    Published: 1979
    Released: April 19, 2006
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    Bis(N-cyclohexylsalicylideneaminato)copper(II) crystallizes in two forms: one is a brown crystal (Form I), and the other is a green one (Form II). The crystal structure of Form II has been determined by X-ray analysis. The green crystals are monoclinic; space group, P21/n. The cell dimensions are a=23.134(6), b=9.525(3), c=21.472(8) Å, β=99.42(1)°, and Z=8. The structure was deduced by the heavy-atom method and was refined to a final R value of 0.082 for 1883 observed reflections by the block-diagonal least-squares method. The molecular structure in Form II is dimeric, in contrast with the case of Form I, which is composed of a monomeric molecule. The two monomeric halves are joined by two Cu–O bonds with distances of 2.60(1) and 2.64(1) Å. Each copper(II) ion is penta-coordinated in a distorted square-pyramidal configuration. The molecular structures in Form I and II have been compared with those of the related Cu(II) compounds.
  • Yasushi Inoue, Yoshimune Yamada
    1979 Volume 52 Issue 12 Pages 3528-3531
    Published: 1979
    Released: April 19, 2006
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    The direct-precipitation method was studied as a possible way to synthesize crystalline zirconium phosphate of a large and uniform crystal size. The yield and the crystal size were examined as functions of the initial hydrofluoric-acid and phosphoric-acid concentrations and the warming temperature. The conditions for preparing the largest crystal were: ZrOCl2·8H2O, 0.13 M; hydrofluoric acid concentration, 0.715 M; phosphoric acid concentration, 5 M; temperature, 50 °C. Those for preparing the material with uniform crystal-size distribution and a possibly large-mean crystal size were: ZrOCl2·8H2O, 0.13 M; hydrofluoric acid concentration, 0.715 M; phosphoric acid concentration, 9 M; temperature, 60 °C. The product was confirmed to be crystalline Zr(HPO4)2·H2O by means of chemical, thermal, and X-ray analyses, and by an examination of the titration curve.
  • Hidetoshi Kita, Shin-ichi Miyake, Koji Tanaka, Toshio Tanaka
    1979 Volume 52 Issue 12 Pages 3532-3538
    Published: 1979
    Released: April 19, 2006
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    Kinetics of the oxidations of dialkyldithiocarbamatocopper(I), [{Cu(S2CNR2)}4] (R=Et, n-Pr), and -silver(I), [{Ag(S2CNR2)}6] (R=Et, n-Pr, i-Pr), with the corresponding tetraalkylthiuram disulfide, [(R2NC(S)S) \llap–2], were investigated in dichloromethane employing a stopped-flow technique. The reactions are interpreted to proceed by a mechanism involving a rapid equilibration (i) (the multi-step equilibrium constant=K0) to form adduct,
    (Remark: Graphics omitted.)
    [M(S2CNR2){(R2NC(S)S) \llap–2}], which are decomposed in a rate-determining step (the rate constant=k) yielding the final products, [M(S2CNR2)2]. According to this mechanism, the rate law in the presence of excess [(R2NC(S)S) \llap–2] is expressed as v=K0k[[(R2NC(S)S) \llap–2]][[{M(S2CNR2)}x]]/(1+K0[[(R2NC(S)S) \llap–2]]), where K0k(25 °C)=1.17×104 (Et), 5.70×103 (n-Pr) M−1 s−1 (M=mol dm−3) for the copper system, and K0(25 °C)=28.2 (Et), 49.1 (n-Pr), 86.7 (i-Pr) M−1 and k(25 °C)=2.17 (Et), 1.50 (n-Pr), 6.56 (i-Pr) s−1 for the silver system. The activation parameters also were determined and the nature of transition states is discussed.
  • Tadao Fujita, Toshio Yamaguchi, Hitoshi Ohtaki
    1979 Volume 52 Issue 12 Pages 3539-3544
    Published: 1979
    Released: April 19, 2006
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    An X-ray diffraction study has been carried out at 25 °C for aqueous ethylenediamine(en) solutions of zinc(II) nitrate, the mole ratios, en/Zn, in the solutions being 2.252 and 3.204. In the former solution bis(ethylenediamine)zinc(II) complex existed as the main species, while in the latter tris(ethylenediamine)zinc(II) complex was predominant. The X-ray scattering data of the solution containing the bis-complex showed that four nitrogen atoms within the two ethylenediamine molecules were tetrahedrally coordinated to the zinc(II) ion at a distance of 2.131 (9) Å. The nonbonding Zn…C distance was also determined to be 2.89(2) Å. In the tris-complex in which the zinc(II) ion was coordinated with the six nitrogen atoms, the Zn–N and Zn…C distances were 2.276(5) Å and 3.00(1) Å, respectively. Raman spectra of the solutions supported the structures of the complexes.
  • Hiroaki Kido, Kazuo Saito
    1979 Volume 52 Issue 12 Pages 3545-3548
    Published: 1979
    Released: April 19, 2006
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    Tris(acetylacetonato[2-14C]) cobalt (III) undergoes ligand isotopic exchange with acetylacetone (Hacac) in acetonitrile at 85–100 °C without decomposition and solvolysis. The exchange rate is proportional to the complex concentration (0.002–0.007 M, 1 M=1 mol dm−3), the first-order rate constant ko being independent of [Hacac] (0.001–0.97 M). ko=1.6×10−5 s−1 at 93.2 °C. The activation enthalpy and entropy are 38±4 kcal mol−1 (1 cal= 4.18J) and 23±8 cal K−1 mol−1, respectively. Trichloroacetic acid (<0.02 M) gives acid catalysis. The ratedetermining step should be the SN1 Co–O cleavage in a chelate ring to give a five coordinate intermediate.
  • Akimasa Yajima, Ryoko Matsuzaki, Yuzo Saeki
    1979 Volume 52 Issue 12 Pages 3549-3552
    Published: 1979
    Released: April 19, 2006
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    The products formed by the heating of VCl2O in an oxygen stream at various temperatures were examined by chemical and X-ray analysis. The reaction products between VCl3 and oxygen were examined in the same manner. The reaction process between VCl2O and oxygen may be represented as follows: VCl2O reacts with oxygen above ca. 170 °C to form V2O5 and VCl3O, 12VCl2O(s)+3O2(g)→2V2O5(s)+8VCl3O(g), and this reaction is accompanied by the reaction, 4VCl2O(s)+3O2(g)→2V2O5(s)+4Cl2(g). The reaction process between VCl3and oxygen may be represented as follows: VCl3 reacts with oxygen above ca. 100 °C to form VCl3O, 2VCl3(s)+O2(g)→2VCl3O(g), and this reaction is accompanied by the reaction, 2VCl3(s)+O2(g)→2VCl2O(s)+Cl2(g).
  • Tomikatsu Kudo, Yoichi Shimura
    1979 Volume 52 Issue 12 Pages 3553-3558
    Published: 1979
    Released: April 19, 2006
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    The theoretically possible eight optical isomers of hexakis(ethylenediamine)-hexa-μ-hydroxo-tetracobalt(III) ion, [Co{(OH)2Co(en)2}3]6+, were separated by column chromatography, absorption and circular dichroism spectra being measured in the visible and ultraviolet region in 0.01 mol dm−3 HCl and 0.15 mol dm−3 Na2SeO3 solutions. Absolute configurations were determined by means of circular dichroism spectra and the characterization of mononuclear cobalt(III) ions produced by decomposition of the tetranuclear isomers in an acid solution. The additivity of the two main circular dichroism contributions due to the chiral CoO6 and CoN4O2 chromophores is discussed, and the configurational chirality of CoO6 chromophore is expressed by summing up the contributions from three pairs of CoN4O2 chromophores as in the so-called ring-pairing method.
  • Hiroko Wada, Genkichi Nakagawa
    1979 Volume 52 Issue 12 Pages 3559-3562
    Published: 1979
    Released: April 19, 2006
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    The rates of the substitution reactions of copper(II) chelates of metallochromic indicators such as 1-(2-pyridylazo)-2-naphthol (PAN, Hpan), 1-(2-thiazolylazo)-2-naphthol (TAN, Htan), 2-(2-pyridylazo)-4-methylphenol (PAC, Hpac), 2-(2-thiazolylazo)-4-methylphenol (TAC, Htac), 4-(2-pyridylazo)resorsinol (PAR, H2par), and 4-(2-thiazolylazo)resorcinol (TAR, H2tar) were determined. The rate laws can be written as −\fracd[CuL]dt=kedta′CuL [CuL][edta′] for PAN, TAN, PAC, and TAC in the pH range of 4 to 6.5, and −\fracd[(CuL)′]dt=(kedta′CuL[CuL]+kedta′CuHL[CuHL])[edta′], where [(CuL)′]=[CuL]+[CuHL], for PAR and TAR in the pH range of 3.5 to 6.5. In the pH range lower than 3.5 the laws are written as −\fracd[CuL]dt=(kedta′CuL[edta′]+kHCuL[H])[CuL] for PAN, and as −\fracd[CuHL]dt=(kedta′CuHL[edta′]+kHCuHL[H])[CuHL] for PAR and TAR. The rate constants (μ=0.1, 25 °C, at dioxane 2 vol% or 5 vol% (PAN and TAN) (dm3 mol−1 s−1)) are kedta′Cu(tan)=2.8×104, kedta′Cu(pac)=8.0×104, kedta′Cu(tac)=4×106, kedta′Cu(par)=2.0×103, kedta′Cu(tar)=6.3×104, kedta′Cu(Hpar)=1.2×104, kedta′Cu(Htar)=7.9×105, kHCu(pan)=6.5×10, kHCu(Hpar)=6.6×102, and kHCu(Htar)=1.2×104. The rate constants, kedta′CuL are inversely proportional to the basicities of the donor atoms of indicators. Thus, the rate of color change of thiazolylazo compound is larger than that of corresponding pyridylazo compound in the chelatometry of copper(II).
  • Mamoru Nakano, Shinichi Kawaguchi
    1979 Volume 52 Issue 12 Pages 3563-3568
    Published: 1979
    Released: April 19, 2006
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    The cis-trans isomeric pairs of diisothiocyanato-, dinitrito-, diazido-, diaqua-, and aquahydroxo-bis(trimethylenediamine)chromium(III) complexes have been obtained as crystals and characterized by infrared and electronic absorption spectra. The cis isomers of diisothiocyanato and diazido complexes as well as [Cr(N3)2(en)2]ClO4 were resolved and the absolute configurations of (+)589-cis-[Cr(NCS)2(tn)2]SCN, (+)589-cis-[Cr(N3)2(tn)2]ClO4, and (−)589-cis-[Cr(N3)2(en)2]ClO4 were all assigned to Δ.
  • Shoji Kajigaeshi, Shizuo Fujisaki, Ichishi Aizu, Hiroshi Hara
    1979 Volume 52 Issue 12 Pages 3569-3572
    Published: 1979
    Released: April 19, 2006
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    The conformations of 9,9-di(9-fluorenyl)fluorene derivatives (1) with substituents at the 2- or 2,7-positions in a terminal fluorene ring were illustrated by the gauche-gauche forms at room temperature. DNMR studies of 1 gave the values of about 85–88 kJ/mol for the free energy of activation (ΔG\ eweq) for the restricted rotation around the C(9)–C(9) bonds. The conformation of 9,9-di(9-fluorenyl) fluorene, the parent compound of 1, was also shown to the only gauche-gauche (+sc, +sc or −sc, −sc) form at room temperature.
  • Yukito Murakami, Akio Nakano, Kiyoshi Matsumoto, Kiyoshi Iwamoto
    1979 Volume 52 Issue 12 Pages 3573-3578
    Published: 1979
    Released: April 19, 2006
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    In order to clarify micro-environmental effects on the reactivity of mercapto groups in enzymes, cationic surfactants bearing a mercapto group, N-hexadecyl-Nα-(3-trimethylammoniopropionyl)-L-cysteinamide bromide (CM·Cys-1) and N-dodecyl-Nα-(6-trimethylammoniohexanoyl)-L-cysteinamide bromide (CM·Cys-2), were synthesized and their kinetic behavior investigated. The surfactants above their critical micelle concentrations markedly catalyzed the decomposition p-nitrophenyl hexanoate (PNPH) and acetate (PNPA), the concentrationrate profiles being found to be those for typical micelle-catalyzed reactions. The rate constants for the degradation of PNPH as catalyzed by CM·Cys-1 and -2 in the micellar phase are 0.482 and 0.197 s−1, respectively, in 9.8% (v/v)ethanol–1.0%(v/v)dioxane–1.0%(v/v)methanol-water at 30.0±0.1 °C, pH 8.65, and μ0.10 (KCl). The difference in catalytic activity can be attributed partly to the micro-environmental effect on the pKa value of the mercapto group lying at the reaction center. The rate constants for the thiolate anions (true reactive species) of CM·Cys-1 and -2 to react with PNPH were identical with each other irrespective of the nature of the surfactants. The electrostatic effect provided by the cationic charge in the Stern layer, which acts to reduce the pKa value of the reactive mercapto group, seems to play a more important role than the desolvation effect on the thiolate anion by the hydrophobic field.
  • Takumi Tanaka, Kiichiro Nakajima, Toru Maeda, Akihiro Nakamura, Noboru ...
    1979 Volume 52 Issue 12 Pages 3579-3581
    Published: 1979
    Released: April 19, 2006
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    A new synthesis of threonine O-peptides via the ring opening reaction of aziridine peptide with carboxylic acid has been investigated. Benzyl (2S,3S)-1-[N-(benzyloxycarbonyl)glycyl]-3-methyl-2-aziridinecarbonylglycinate was treated with several N-protected amino acids or dipeptides at their mixed melting point, and the corresponding O-aminoacyl or dipeptidyl esters of L-threonine peptide derivative were obtained in good yields without racemization.
  • Toshikazu Ibata, Kimiko Jitsuhiro
    1979 Volume 52 Issue 12 Pages 3582-3585
    Published: 1979
    Released: April 19, 2006
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    The Cu(acac)2 catalyzed decomposition of o-methoxycarbonyl-α-diazoacetophenone (3) in the presence of acetylenic dipolarophiles gave cycloadducts of the dipolarophiles with 1-methoxybenzo[c]pyrylium-4-olate generated by the intramolecular carbene-carbonyl reaction of the corresponding carbene. The direction of the cycloadditions of unsymmetrically substituted acetylenes has been determined on the basis of the NMR coupling pattern and chemical shift of the bridgehead methine protons of the adducts. Treatment of 3 with strong dipolarophiles such as dibenzoylacetylene or dimethyl acetylenedicarboxylate gave spiro pyrazoles by the direct cycloaddition of 3 and acetylenes followed by the elimination of methanol.
  • Iwao Tanimoto, Keiko Kushioka, Toyokichi Kitagawa, Kazuhiro Maruyama
    1979 Volume 52 Issue 12 Pages 3586-3591
    Published: 1979
    Released: April 19, 2006
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    Anthracene is selectively chlorinated with solid copper(II) chloride to give a quantitative yield of 9-chloroanthracene. The tentative reaction mechanisms so far proposed fail to explain the nonreactivity of some other hydrocarbon homologues, e.g. naphthalene and phenanthrene, toward copper(II) chloride. The present study revealed that the oxidative half-wave potentials (E1⁄2ox) of all reactive hydrocarbon homologues were less than 1.26 V. On the basis of this finding we postulate a reaction mechanism involving one electron transfer from hydrocarbon to copper(II) chloride.
  • Tsutomu Sakakibara, Yoko Dogomori, Yuichiro Tsuzuki
    1979 Volume 52 Issue 12 Pages 3592-3596
    Published: 1979
    Released: April 19, 2006
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    The reaction of N,N-dialkylaniline with palladium(II) acetate or di-μ-acetato-bis[α-(dimethylamino)-o-tolyl]dipalladium (B) gave 4,4′-bis(dialkylamino)diphenylmethane as a major product. It was elucidated that the origin of –CH2– in the product might be methyl group of palladium acetate and the primary reaction product might be N,N-dialkyltoluidine. The absorption spectra of the initial reaction mixture of N,N-dimethylaniline with B in acetic acid at room temperature showed the absorption maximum at 470 nm and at 750 nm. The latter peak was tentatively assigned to N,N-dimethylaniline radical cation-palladium (I) acetate complex, which was suggested as a key-intermediate for the formation of diarylmethanes.
  • Toshikazu Ibata, Ryohei Sato
    1979 Volume 52 Issue 12 Pages 3597-3600
    Published: 1979
    Released: April 19, 2006
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    The BF3-catalyzed decomposition of diazo carbonyl compounds in nitriles have afforded the corresponding oxazoles in high yields. This method is applicable to diazo carbonyl compounds such as m- and p-substituted diazoacetophenones, ethyl diazoacetate, 1,2-diphenyl-2-diazoethanone, dibenzoyldiazomethane, and dimethyl diazomalonate. Bis(diazo ketone)s such as terminal bis(diazoacetylated) alkanes (III1−4: n=6, 8, 10, 12) and m-and p-bis(diazoacetyl)benzenes also gave the corresponding bisoxazoles in a similar reaction. The reaction has been interpreted in terms of a stepwise mechanism via betaine intermediates initiated by the attack of BF3 on the carbonyl oxygen of diazo carbonyl compounds. The emission spectra of oxazoles are described.
  • Kimitoshi Saito, Tadashi Sato
    1979 Volume 52 Issue 12 Pages 3601-3605
    Published: 1979
    Released: April 19, 2006
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    The irradiation of thiolane-2,4-dione (thiotetronic acid) and its derivatives, 1a1d, in methanol in the presence of bases induced the reductive ring cleavage to give β,β′-diketo esters. The base-induced reductive ring cleavage was also observed in aprotic solvents, such as acetonitrile or acetone, although the products were obtained as β,β′-diketo amides in these cases. On the other hand, the irradiation of 1a1d in water in the presence of bases induced a rearrangement of the carbon skeleton to give succinic thioanhydrides, γ-keto amides or succinamides, along with the reduction products. When pyridine was used as a base in the photolysis in water, two 3-acetyl derivatives, 1a and 1b, gave γ-keto thiols and the corresponding disulfides, resulted from another type of rearrangement of the carbon skeleton. Conceivable reaction mechanisms were discussed.
  • Seiji Shinkai, Kenji Mori, Yumiko Kusano, Osamu Manabe
    1979 Volume 52 Issue 12 Pages 3606-3610
    Published: 1979
    Released: April 19, 2006
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    The rate constants for the reaction of the title flavin and the monomeric analogues with 1-benzyl-1,4-dihydronicotinamide (BzlNH), 1-nitroethanide ion, glutathione (GSH), and thiophenol (PhSH) were determined at 30 °C. Although the reactivity of 8α-AcHisFl is slightly improved as compared with that of unmodified flavin, the rate constants for 8α-PyFl which is expected to mimic the reactivity of protonated 8α-AcHisFl were significantly increased. The rate constants for the oxidation of anionic reductants(1-nitroethanide ion, GSH, and PhSH) were further increased by immobilization of the 8α-PyFl structure in quaternized 4VP polymers. The kinetic results implicate that (1) with regard to the action of a flavin covalently-linked to enzymes via histidine residue, the flavin must be more reactive in acidic pH region due to protonation of the histidine than in basic pH region, (2) the cationic polyelectrolyte environment accelerates selectively the oxidation of anionic reductants, and (3) the title flavin serves as a strong, selective oxidizing agent under ambient reaction conditions.
  • Nanao Watanabe, Sakae Uemura, Masaya Okano
    1979 Volume 52 Issue 12 Pages 3611-3614
    Published: 1979
    Released: April 19, 2006
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    The reaction of primary and secondary alkyl halides with mercury(II) acetate in oxiranes, oxetanes, and tetrahydropyran results in ring-opening to give the corresponding alkoxyalkyl acetates. Similar reactions with mercury(II) thiocyanate in oxetanes afford alkoxyalkyl isothiocyanate and thiocyanate, ROCH2C(R′)2CH2NCS and ROCH2C(R′)2CH2SCN, where the isomer ratios (N/S ratios) are 82–96/4–18. It is suggested that the reactions involve the initial formation of a three-, four-, or six-membered O-alkyloxonium ion intermediate and subsequent attack by XHgZ2.
  • Yoshio Inagaki, Renji Okazaki, Naoki Inamoto
    1979 Volume 52 Issue 12 Pages 3615-3618
    Published: 1979
    Released: April 19, 2006
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    Reaction of 2,4-di-t-butyl-6-methyl-N-thiosulfinylaniline (1) with m-chloroperbenzoic acid (MCPBA) afforded the corresponding aniline and N-sulfinylaniline. Reaction of MCPBA with 2,4,6-tri-t-butyl-7,8-dithia-9-azabicyclo[4.3.0]nona-2,4,9-triene equilibrated with 2,4,6-tri-t-butyl-N-thiosulflnylaniline gave 2,4,r-6-tri-t-butyl-7,8-dithia-9-azabicyclo[4.3.0]nona-2,4,9-triene t-7-oxide (12), 4,6-di-t-butyl-3H-1,2,3-benzodithiazole 2-oxide (13), and 2,4,6-tri-t-butyl-N-sulfinylaniline (14). The oxide 13 was considered to be produced via a primary product 2,4,r-6-tri-t-butyl-7,8-dithia-9-azabicyclo[4.3.0]nona-2,4,9-triene t-8-oxide which was found to be unstable above −30 °C. Thermolysis of 12 affording 13, 14, and 2,4,6-tri-t-butylaniline demonstrated oxygen or sulfur migration in the thiosulfinate type compound. Bromine reacted with 1 to give bis(2,4-di-t-butyl-6-methylphenyl)sulfur diimide probably via a thionitroso intermediate. Neither trimethyloxonium tetrafluoroborate nor trimethylsilyl chloride reacted with 1.
  • Kazuhiko Tanaka, Nobuyuki Yamagishi, Rikuhei Tanikaga, Aritsune Kaji
    1979 Volume 52 Issue 12 Pages 3619-3625
    Published: 1979
    Released: April 19, 2006
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    The lithium enolates of O-alkyl S-alkoxycarbonylmethyl dithiocarbonates and monothiocarbonates were found to be efficient reagents for the synthesis of α,β-unsaturated esters from carbonyl compounds by single-step procedure. The dianions of ethyl mercaptoacetate and ethyl 2-mercaptopropionate were successfully generated by treatment with 2.2 equivalents of lithium diisopropylamide (LDA) in the presence of N,N,N′,N′-tetramethylethylenediamine (TMEDA) at −78 °C in THF. The dianions so formed are highly reactive toward various electrophiles. The procedure leads to a novel one-pot synthesis of α,β-unsaturated carboxylic esters from carbonyl compounds.
  • Akihiko Harayama, Tsutomu Tsuchiya, Sumio Umezawa
    1979 Volume 52 Issue 12 Pages 3626-3628
    Published: 1979
    Released: April 19, 2006
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    Neamine and its position isomer were synthesized from 3,4-di-O-acetyl-2-deoxy-2-(p-methoxybenzylidene-amino)-6-O-tosyl-α-D-glucopyranosyl bromide and racemic 5,6(4,5)-O-cyclohexylidene-2-deoxy-1,3-bis-N-(ethoxycarbonyl) streptamine. Influence of the N-protecting groups of 2-deoxystreptamine derivatives for glycosylation was discussed. The unusual Δ[M]TACu value of the position isomer of neamine was ascribed to the interaction between the 6′-amino group and other groups.
  • Toshio Sugita, Yoshimi Shiraiwa, Masayuki Hasegawa, Katsuhiko Ichikawa
    1979 Volume 52 Issue 12 Pages 3629-3631
    Published: 1979
    Released: April 19, 2006
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    Stilbene bromohydrin derivatives (Ph–CHBr–CHY–Ph: Y=OAc, OSO2CH3, OCH3, SCH3) and stilbene dibromide underwent β-elimination reaction with tetrakis(triphenylphosphine)palladium(0) to give stilbene. The stereochemistry of eliminations is nonselective except in the case of dibromide, where anti-selectivity is observed. A coupling reaction occurred favorably in the case of Y=OCH3.
  • Tamejiro Hiyama, Hajime Yamamoto, Koji Nishio, Katuzi Kitatani, Hitosi ...
    1979 Volume 52 Issue 12 Pages 3632-3637
    Published: 1979
    Released: April 19, 2006
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    Treatment of bromocyclopropanes with excess dibutylcopperlithium in tetrahydrofuran at −48 °C gives the respective organocopper intermediates which upon quenching with excess alkyl halides afford alkylated cyclo-propanes with retention of the configuration. This process is applied to the synthesis of methyl cascarillate. Bromoarenes are also reduced with dibutylcopperlithium and allylarenes are prepared therefrom.
  • Seizi Kozuka, Ikuya Naribayashi
    1979 Volume 52 Issue 12 Pages 3638-3639
    Published: 1979
    Released: April 19, 2006
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    A kinetic study has been conducted on the reaction of (arylthio)trimethylstannane with benzoyl chloride giving chlorotrimethylstannane and S-aryl thiobenzoate. The reaction has been found to obey a second order kinetic equation. A mechanism involving bimolecular nucleophilic attack of the sulfur atom on the acyl carbon has been suggested for the reaction based on the substituent effects of arylthio and benzoyl moieties.
  • Kyung-Tae Kang, Renji Okazaki, Naoki Inamoto
    1979 Volume 52 Issue 12 Pages 3640-3646
    Published: 1979
    Released: April 19, 2006
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    Reaction of 1,2-benzodithiole-3-thione with N,N′-dialkyl-1,2-ethanedianiine afforded o-thioquinone methides with a ketene aminal group (6) in high yields. Two similar thionaphthoquinone methides were also prepared. o-Thioquinone methide derived from N,N′-dimethyl-o-phenylenediamine was prepared from 3-chloro-1,2-benzodithiol-3-ylium chloride (10). These compounds were found to exist as a monomer of a considerable betaine nature. Reactions of 6a (N,N′-dimethyl derivative) with dimethyl acetylenedicarboxylate and dibenzoylacetylene led to [4+2] adducts. o-Thioquinone methides with a ketene acetal group were obtained from desulfurization of spiro[1,3-benzodioxole-2,3′-[1,2]benzodithiole] with trimethyl phosphite, which are equilibrated with two kinds of aggregates; one is a dimer and the other is a trimer or a higher oligomer. Reactions of 10 with o-mercaptophenol and 1,2-benzenedithiols gave spiro[1,2-benzodithiole-3,2′-[1,3]benzoxathiole] (29) and spiro[1,2-benzodithiole-3,2′-[1,3]benzodithiole] (39 and 40), respectively. o-Thioquinone methide with a ketene monothioacetal group (30) was prepared by desulfurization of 29. The violet compound 30 is equilibrated with a colorless dimer. This o-thioquinone methide reacted with olefins and an acetylene having electron-withdrawing groups to give 1,4-cycloaddition products. Similar desulfurization of 39 and 40 gave o-thioquinone methides with dithioacetal group. Their properties were very similar to those of o-thioquinone methides with dithioacetal group prepared by the photoreaction of 2 with olefins.
  • Yoshio Okahata, Reiko Ando, Toyoki Kunitake
    1979 Volume 52 Issue 12 Pages 3647-3653
    Published: 1979
    Released: April 19, 2006
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    Catalytic hydrolysis of p-nitrophenyl esters (acetate and nonanoate) by hydroxamate and imidazole nucleophiles was studied at 30 °C in the presence of aqueous aggregates of single-chain (hexadecyl), double-chain (didodecyl and dioctadecyl) and triple-chain (trioctyl) ammonium amphiphiles. These three types of ammonium salts give rise to very different aggregate morphologies. The rate constant of ester cleavage by the nucleophiles was enhanced several hundred folds in the presence of these hydrophobic aggregates. Simple long-chain nucleophiles possessed esterolytic reactivities which reflect the hydrophobic microenvironment of the respective aggregates: single-chain<double-chain<triple-chain. On the other hand, the cholesteryl ester of imidazolecarboxylic acid showed an especially high reactivity when bound to the didodecylammonium bilayer. Cholic acid-derived nucleophiles showed normal reactivity patterns. Apparently, specific binding of the cholesterol derivative to the bilayer is responsible for the unusual catalytic behavior.
  • Otohiko Tsuge, Hiroyuki Watanabe, Yoko Kiryu
    1979 Volume 52 Issue 12 Pages 3654-3658
    Published: 1979
    Released: April 19, 2006
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    The reactions of highly strained 1,2-diphenyl-1-azaspiro[2.2]pentane (1) and 2-phenyl-1-azaspiro[2.2]pent-1-ene (2) with C,N-diarylnitrilimines (3) were described. The reaction of 1 with 3 gave the corresponding 4,5,7,8-tetraphenyl-4,6,7-triazaspiro[2.5]oct-5-ene, 1,5,7,8-tetraphenyl-5,6,8-triazaspiro[3.4]oct-6-ene, 1,3,5-triphenyl-2-pyrazoline, 1,3,4-triphenyl-1,2,4-triazolin-5-one, and/or 1,3,4,6,8-pentaphenyl-1,2,4,6,7-pentaazaspiro[4.4]nona-2,7-diene, whose yields depended on the reaction conditions. The pathways for the formation of products are also postulated. The azaspiropentene 2 readily reacted with 3 to give the corresponding 1,2,4-triphenyl-2,3,5-triazabicyclo[4.2.0]octa-3,5-diene arising from the rearrangement of initial 1,3-cycloadduct.
  • Yukihisa Fujita, Akihiko Miyanaga, Yukinao Noda
    1979 Volume 52 Issue 12 Pages 3659-3662
    Published: 1979
    Released: April 19, 2006
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    The thermal denaturation of lysozymc in aqueous alcohol solution has been investigated by differential scanning calorimetry. The alcohols employed were methanol, ethanol, isomeric propyl alcohols and butyl alcohols as monohydric alcohols, and ethylene glycol and glycerol as polyhydric alcohols. In monohydric alcohols, the temperature of denaturation, Td, of lysozyme decreased linearly with increasing alcohol concentration, which became pronounced with an increasing in the hydrophobic character. The enthalpy of denaturation, ΔHd, of lysozyme showed a complex dependence on the solvent composition; the ΔHd first increased with increasing alcohol concentration and then started decreasing at different concentrations for each alcohol. The branching of the alkyl chain decreased the destabilizing effect of the alcohol on the native conformation of the protein. In polyhydric alcohols, both Td and ΔHd increased with increasing alcohol concentration. The polyhydric alcohols stabilized the native conformation of the protein in contrast with the monohydric alcohols. The results are discussed in terms of the hydrophobic and hydrophilic characters of the alcohols.
  • Soichi Otsuka, Tsutomu Mitsuhashi, Michinori \={O}ki
    1979 Volume 52 Issue 12 Pages 3663-3666
    Published: 1979
    Released: April 19, 2006
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    The title compounds were prepared by the reaction between 9-(1-cyano or 1-methoxycarbonyl-1-methylethyl)anthracene and substituted benzynes and their rotational isomers were isolated. The barriers to rotation of these compounds were found to be 35–36 kcal/mol and 32–34 kcal/mol for the processes dlmeso and mesodl, respectively.
  • Soichi Otsuka, Hiroshi Kihara, Tsutomu Mitsuhashi, Michinori \={O}ki
    1979 Volume 52 Issue 12 Pages 3667-3670
    Published: 1979
    Released: April 19, 2006
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    Restricted rotation about a Csp3–C(=O) bond in title compounds is found by 1H NMR spectra of the dl forms. The barriers to rotation are obtained by the DNMR method to be ca. 15 kcal/mol. Infrared spectra which exhibit two conformations in the dl and the meso forms are also reported.
  • Masahiro Nakada, Kiichiro Ishibashi, Sachio Fukushi, Minoru Hirota
    1979 Volume 52 Issue 12 Pages 3671-3675
    Published: 1979
    Released: April 19, 2006
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    The Jacobsen rearrangement of tribromobenzenes was investigated at 110–180 °C in concentrated sulfuric acid. The reaction proceeds exclusively via the intramolecular 1,2-migration of the bromine atom, which is accelerated by the steric repulsion of the neighboring group. Sulfonation of both the reactant and the products occurs simultaneously with the rearrangement. The migration of bromine atoms in the sulfonic acids proceeds far more slowly, the rearranged products not being formed to any considerable extent by sulfonic acids.
  • Tadashi Yoshida, Yosuke Maekawa, Hiroyuki Uchino, Susumu Yokoyama
    1979 Volume 52 Issue 12 Pages 3676-3678
    Published: 1979
    Released: April 19, 2006
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    The spin-lattice relaxation time, T1, of carbons was measured for various types of carbons in ring-type fractions separated from coal-derived oil. The T1 for most carbons in the coal-derived oil was less than 2 s because of the existence of free radicals, while the T1’s of aromatic non-protonated carbons in the monocyclic and bicyclic aromatics fractions were approximately 12–15 s. The effects of a relaxation reagent on the T1 were also discussed.
  • Vinod Gujral, S. R. Gupta
    1979 Volume 52 Issue 12 Pages 3679-3681
    Published: 1979
    Released: April 19, 2006
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    1,3,5-Trihydroxyxanthen-9-one reacts with 2-methylbut-3-en-2-ol in presence of a catalytic amount of BF3-etherate to yield a mixture of 1,3,5-trihydroxy-2,4-bis-(3-methylbut-2-enyl)xanthen-9-one, in poor yield, identical with natural 8-desoxygartanin along with 1,3,5-trihydroxy-4-(3-methylbut-2-enyl)xanthen-9-one (3), in good yield, and 1,3,5-trihydroxy-2-(3-methylbut-2-enyl)xanthen-9-one (4) in poor yield. Compounds 3 and 4, the probable biogenetic precursors of 6-desoxyisojacareubin and 6-desoxyjacareubin, have been reported to occur in nature as such but were characterised as their dimethyl ethers. Compounds 3 and 4 on oxidative cyclisation with DDQ, gave 6-desoxyisojacareubin and 6-desoxyjacareubin respectively, completely identical with authentic natural samples.
  • Akiko Kobayashi, Yukiyoshi Sasaki, Hayao Kobayashi
    1979 Volume 52 Issue 12 Pages 3682-3691
    Published: 1979
    Released: April 19, 2006
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    X-Ray examination, chemical analyses and electrical conductivity measurements have been conducted on the partially oxidized platinum complex Rb1.67[Pt(C2O4)2]·1.5H2O (RbDOX). The cell constants are a=12.690(10), b=17.108(14), c=11.357(3) Å; α=102.04(4), β=115.17(3), γ=43.58(4)°, and the space group is P\bar1. The planar bis(oxalato)platinate ions stack along the crystallographic b axis and the Pt atoms form a sixfold distorted chain. RbDOX is the first example of a sixfold structure. Three independent Pt–Pt distances are 2.717(3), 2.830(3), and 3.015(3) Å. The Pt–Pt distance of 2.717 Å is the shortest spacing so far observed in partially oxidized platinate salts and shorter than the 2.77 Å interatomic separation in Pt metal itself. The oxalate ligands are staggered (46°, 55°, 80°) with respect to the ligands directly above and below them along the chain. Sixfold modulated superstructure of RbDOX is confirmed as the newly found commensurate Peierls structure based on agreement with the period of the Peierls distorted superlattice determined by the degree of partial oxidation. The calculation of Coulomb energy shows that RbDOX has a crystal lattice in which the interchain Coulomb energies are at a minimum indicating the strong tendency of the anti-phase ordering of the nearest-neighbour Pt chains.
  • Tomokazu Matsue, Masamichi Fujihira, Tetsuo Osa
    1979 Volume 52 Issue 12 Pages 3692-3696
    Published: 1979
    Released: April 19, 2006
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    The anodic chlorination of anisole on an α-cyclodextrin (α-CD) chemically modified electrode via ether linkage (α-CD-CME) and a naked graphite electrode with α-CD or β-CD in solution was studied. In the presence of CD, the p- to o-chloroanisole ratio, formed in the reaction, was higher than that in the absence of CD since o-positions of anisole included in CD are blocked by the inner wall of CD. Especially, α-CD had a profound effect on the p-isomer formation. Increasing the concentration of NaCl added as a supporting electrolyte in the presence of α-CD resulted in a decrease in the ratio because of the inhibition effect of chloride ion on the inclusion of anisole in α-CD, whereas such effect was small in the presence of β-CD. The ratio on α-CD-CME was slightly higher than that on the naked electrode. This indicates that α-CD was introduced on the graphite surface but the surface coverage of α-CD was low, which was in accord with the ESCA results of α-CD-CME.
  • Tsutomu Fukasawa, Masaaki Iwatsuki
    1979 Volume 52 Issue 12 Pages 3697-3701
    Published: 1979
    Released: April 19, 2006
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    An unknown yellow precipitate, similar to lead(II) chromate in appearance, has been reported. The precipitate was formed in the detection process of lead(II) ions using chromate ions by a classical qualitative analytical method. The present paper describes the elucidation of the unknown precipitate, and the presence of a series of new chromates iso-structural with the known potassium lead(II) chromate, K2Pb(CrO4)2. The new chromates are explained as new stoichiometric chromates, K4Pb4(CrO4)6 and (NH4)4Pb4(CrO4)6 [=K2Pb2(CrO4)3 and (NH4)2Pb2(CrO4)3], and solid solutions (K, NH4)6−2zPb3+z(CrO4)6 (z=+0.3–+1.2) among the new stoichiometric chromates and the known chromates, K6Pb3(CrO4)6 and (NH4)6Pb3(CrO4)6 [=K2Pb(CrO4)2 and (NH4)2Pb(CrO4)2]. The compositions of the new chromates are dependant on the precipitating conditions. Relationships between compositions, lattice constants, and precipitating conditions are given together with indexed powder diffraction data for references to identification, and the results of thermal analyses.
  • Masahiro Kuramoto
    1979 Volume 52 Issue 12 Pages 3702-3712
    Published: 1979
    Released: April 19, 2006
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    The crystal structures of two diastereoisomeric salts, (+)589-trans(O)-[Co(gly)2en]H-d-tart·3H2O (1) and (−)589-trans(O)-[Co(gly)2en]H-d-tart·H2O (2), have been determined by three-dimensional X-ray analysis. The less-soluble salt (1) is monoclinic; space group, P21; Z=2, a=12.351(5), b=7.671(3), c=10.189(5) Å, and β=110.71(4)° (R=0.043, 2241 reflections). The more-soluble salt (2) is monoclinic; space group, P21; Z=2, a=11.135(4), b=10.037(3), c=7.716(3) Å, and β=98.61(3)° (R=0.064, 2076 reflections). A comparison of the (unit cell volume)/Z values of the two crystals shows that the crystal 1 is more tightly packed than the crystal 2. In both salts, adjacent complex cations form quite similar chain structures linked by (N–H…O) hydrogen bonds. The H-d-tart anions in 1 take a characteristic “head-to-tail” arrangement of an infinite chain of {H-d-tart} along the b-axis. In contrast, this arrangement is not found in the more-soluble salt (2). From these findings, it can be considered that the discrimination of optical isomers in the H-d-tart system originates from the spiral chain structure of {H-d-tart}. The absolute configurations of (+)589- and (−)589-trans(O)-[Co(gly)2en]+ are determined to be Λ-δ and Λ-λ respectively. TG and DSC measurements were carried out for both salts, and the ΔH values of the dehydration step were estimated to be 64.4 kJ mol−1 for 1 and 73.0 kJ mol−1 for 2.
  • Takafumi Kanazawa, Takao Umegaki, Masao Shimizu
    1979 Volume 52 Issue 12 Pages 3713-3717
    Published: 1979
    Released: April 19, 2006
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    Bobierrite, Mg3(PO4)2·8H2O, could be synthesized from mixed solutions of Na2HPO4 and MgSO4 at an initial pH of 6.4–7.0 with the addition of Ca(NO3)2, CuSO4, NiSO4, gelatin, or agar, by heating at 80–90 °C for 2–48 h. X-Ray studies indicated the coexistence of two kinds of lattice in each synthetic Mg3(PO4)2·8H2O crystal. One phase (Phase 1) is monoclinic, space group P21/m or P21 with a=10.08(2), b=27.86(3), c=4.656(7) Å, and β=105.0(2)°. The other phase (Phase 2) is monoclinic, space group C2/m, C2, or Cm, with a=10.07(2), b=13.38(2), c=4.656(7) Å, and β=105.0(2)°. If a centrosymmetric space group C2/m is assumed for the latter, Phase 2 may be considered to be a new polymorph of Mg3(PO4)2·8H2O, one belonging to the vivianite series. Newberyite, MgHPO4·3H2O, was also formed in the above synthetic procedure. This phosphate was precipitated under slightly more acidic conditions than those where Mg3(PO4)2·8H2O was obtained.
  • Hideo Akaiwa, Hiroshi Kawamoto, Eiji Yoshimatsu
    1979 Volume 52 Issue 12 Pages 3718-3720
    Published: 1979
    Released: April 19, 2006
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    Cadmium(II) has been quantitatively separated from zinc(II) by an ion-pair extraction system. An ion-pair consisting of cadmium(II) and 1,10-phenanthroline (phen) was found to be preferentially extracted into chloroform from an aqueous chloride solution containing zinc(II). The extracted species in chloroform reacted with dithizone (H2Dz) to give the reddish mixed complex Cd(HDz)2(phen) having an absorption maximum at approximately 505 nm. The resulting calibration curve obeys Beer’s law, the Sandell sensitivity being 0.0013 μg cm−2. The effect of diverse ions has been examined, and a new highly selective method for the spectrophotometric determination of trace amounts of cadmium in metallic zinc established.
  • Yuzi Takayama
    1979 Volume 52 Issue 12 Pages 3721-3723
    Published: 1979
    Released: April 19, 2006
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    A new method of the surface modification of a porous polymer has been developed and applied to packing materials for gas chromatography. The porous polymer was coated with a α,β-unsaturated polyester solid polymer, which had a high acid value and which was cross-linked on the porous polymer by polymerization. By using this in gas chromatography, formic acid peaks are completely separated from acetic acid and water peaks without any apparent tailing. This polyester layer was not extractable and could stably be used at 230 °C or higher. If the diallyl phthalate polymer is used instead of the α,β-unsaturated polyester, propionic acid and acrylic acid, which are very diffecult to separate, were resolved. The present method may be applicable to some components of composite materials.
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