Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 65 , Issue 12
Showing 1-48 articles out of 48 articles from the selected issue
  • Katsuhiro Nomura, Shoichiro Ikeda, Kaname Ito, Hisahiko Einaga
    1992 Volume 65 Issue 12 Pages 3221-3227
    Published: 1992
    Released: July 29, 2006
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    The crystal structure, phase transition, electrical conduction behavior of various kinds of MIIZr4(PO4)6 (MIIZP) compounds (MII = Mg, Ca, Sr, Ba, Mn, Co, Ni, Zn, Cd, and Pb) have been investigated. The Mg, Co, Ni, and Zn compounds are of the β-Fe2(SO4)3-type structure and show an order-disorder transition between 600 and 720 °C; the Ca, Sr, Ba, Cd, and Pb compounds, however, are of the NASICON-type structure and do not show any phase transition between r.t. and 1000 °C. The Mn compound sintered at 900 °C shows the former characteristics (the phase transition temperature is around 560 °C), and that sintered above 900 °C the latter. The ZnZP and MnZP show the highest conductivity, ca. 2 × 10−3 and ca. 8 × 10−4 S cm−1 at 800 °C, in the β-Fe2(SO4)3- and the NASICON-type structure, respectively. The ionic size of the mobile cation is the predominant factor regarding ionic conduction in the zirconium phosphate framework.
  • Akihiro Yoshino, Kensuke Takahashi, Tyo Sone
    1992 Volume 65 Issue 12 Pages 3228-3233
    Published: 1992
    Released: July 29, 2006
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    The 13C NMR spectra of fifteen cations formed from chloro- and methylthiophenes were observed in HSO3F solutions at −50 °C. Protonation occurred at one of the α-carbons in all of the cases studied. In these systems, the 13C chemical shifts are classified into four ranges without overlapping. The result is useful for the identification of the carbons in the cationic species. Protonated protons in the cationic species can exchange intramolecularly and intermolecularly, even with those in solvents.
  • Yoshihiro Kubozono, Isao Kohno, Kazuo Ooishi, Sakuhiro Namazue, Masao ...
    1992 Volume 65 Issue 12 Pages 3234-3240
    Published: 1992
    Released: July 29, 2006
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    X-Ray structure analyses and MO calculations have been performed for acetoacetanilide (AAA), and o- and p-chloroacetoacetanilides (o-CAAA and p-CAAA) in order to elucidate the contribution of hydrogen bonding to crystal and molecular structures. The molecular conformations have been classified into two categories, planar for o-CAAA and nonplanar for AAA and p-CAAA. The molecular conformation of o-CAAA can be well-reproduced by the geometry optimization based on the AM1 (Austin Model 1) MO method, while those of AAA and p-CAAA are different from the optimized geometries. The deviation from the optimized structure can be explained on the basis of the formation of intermolecular hydrogen bonding and C–H···O=C interactions in the crystals. The hydrogen bonding of these compounds is discussed together with the infrared (IR) spectral data.
  • Makoto Handa, Tsutomu Idehara, Kenji Nakano, Kuninobu Kasuga, Masahiro ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3241-3252
    Published: 1992
    Released: July 29, 2006
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    The near-ultraviolet absorption band characteristic of dialkoxo-bridged binuclear copper(II) complexes was reinvestigated by using a series of binuclear copper(II) complexes with N,N-dialkyldiaminoalcohols, Cu2{R2N(CH2)mNH(CH2)nO}2X′2 (abbreviated as Cu(R-m-n)X′, X′ = ClO4, BF4). In this study eighteen complexes including ten new compounds were prepared and classified into two types, i.e., type-A and B according to Kida’s classification, based on their temperature dependencies of magnetic susceptibilities (80–300 K) and reflectance spectra. The crystal structures of Cu(n-Bu-3-2)ClO4 (10), Cu(H-3-3)BF4·EtOH (11b), and Cu(Me-3-3)ClO4 (12a) were determined by the single-crystal X-ray diffraction method. The detailed analysis of the structures and reflectance spectra led to the same conclusion as Kida’s one in assigning the near-ultraviolet absorption band. That is, the absorption was ascribed to the charge transfer (CT) from the bridging oxygen’s nonbonding orbital to vacant copper d-orbital. On the other hand, in assigning the origin of the appearance of the CT band in the near-ultraviolet region, the conclusion different from Kida’s one was presented. The origin was interpreted in terms of the red-shift of the band owing to the electrostatic repulsion between the bridging oxygen atoms. Moreover, the unusually low frequency and low intensity of the CT band of 12a were also reasonably explained.
  • Shouichi Kita, Masayasu Shibata, Kengo Uchida
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3253-3256
    Published: 1992
    Released: July 29, 2006
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    The effects of high pressure on the rates of aquation reactions of Cr(bpy)33+ and Cr(phen)33+ have been measured. The activation volumes of aquation were derived as −0.9 ± 0.5 and +5.2 ± 0.4 cm3 mol−1 for Cr(bpy)33+ and Cr(phen)33+, respectively. These values are consistent with those expected from an interchange mechanism involving water penetration to the coordination sphere and an extension of one or both of the Cr-polypyridine bonds.
  • Shinkiti Koto, Naohiko Morishima, Sonoko Shichi, Hisamitsu Haigoh, Mot ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3257-3274
    Published: 1992
    Released: July 29, 2006
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    Dehydrative glycosylations of the 2-, 3-, 4-, and 6-OH groups of D-glucopyranose with hepta-O-benzyl derivatives of glucobioses (O-D-glucopyranosyl-(1→n)-D-glucopyranose; n = 2, 3, 4, or 6) and lactose, in the presence of a ternary mixture of p-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, and triethylamine in dichloromethane showed that the selectivity of the reaction depended on the anomeric configuration and the linking position to the reducing tribenzylglucose moiety of the nonreducing tetrabenzylglucosyl residue and on the class of the OH group to be glycosylated. The use of a quaternary mixture of p-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, N,N-dimethylacetamide, and triethylamine made all but the β(1→2)-linked biosyl donor undergo α-condensation. Several new linear trisaccharides were obtained via debenzylation of the condensates.
  • Masao Hisatome, Kunihiko Nakanishi, Koji Yamakawa, Kozo Kozawa, Tokiko ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3275-3281
    Published: 1992
    Released: July 29, 2006
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    [4](1,1′)[4](3,4′)Ferrocenophane (2a), also trivially called antiprismatic [42]ferrocenophane, which possesses a C2 symmetric configuration has been synthesized via intramolecular oxidative coupling of the dienolate ion derived from 3,4′-diacetyl[4](1,1′)ferrocenophane. The antiprismatic phane (2a) and the corresponding prismatic [4](1,1′)[4](3,3′)ferrocenophane (1a), which is bridged by a C symmetric mode, has been characterized by X-ray analysis and 1H NMR and electronic spectrometries. The crystal data of the phanes are as follows: 1a, orthorhom-bic, Pbca, a = 18.469(4), b = 19.994(4), c = 7.610(2) Å; Z = 8; 2a, triclinic, , a = 7.547(1), b = 8.540(1), c = 5.886(1) Å, α = 96.60(1), β = 107.10(1), γ = 101.71(1)°, Z = 1. Antiprismatic phane 2a has a completely staggered conformation about the two cyclopentadienyl (Cp) rings, while prismatic 1a has an intermediary conformation of eclipsed and staggered forms. The Cp–Fe–Cp distance of 2a (3.260 Å) is shorter than that of 1a (3.275 Å). The hypsochromic shift of the d–d* absorption band of 2a in the electronic spectrum is more remarkable than that of 1a (ferrocene, 443 nm; 1a, 420 nm; 2a, 403 nm in THF). Those results reveal that an antiprismatic bridging mode with tetramethylene chains brings about a higher strain in the molecule compared with a prismatic one.
  • Yoichiro Kitamori, Masafumi Yasunami, Takanori Hioki, Kahei Takase, Ma ...
    1992 Volume 65 Issue 12 Pages 3282-3287
    Published: 1992
    Released: July 29, 2006
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    4-Hydroxy-3H-cyclopent[a]azulen-3-one, a new tricyclic π-conjugated system containing a hydroxyazulene unit and a cyclopentadienone moiety, was synthesized by the application of flash vacuum pyrolysis in the final step. All the proton magnetic resonances of the compound shifted up-field compared with those of the referenced 1,2-dihydro compound in terms of an induced paramagnetic ring current in the periphery of this molecule. The characteristic prototropic tautomerization of 4-hydroxyazulenes was not observed in this system.
  • Kimihiro Murakami, Masayuki Ohashi, Atsuo Matsunaga, Ichiro Yamamoto, ...
    1992 Volume 65 Issue 12 Pages 3288-3293
    Published: 1992
    Released: July 29, 2006
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    (±)-2-(3,4-Carbonyldioxyphenyl)-2-(phthalimidooxy)acetic acid [(±)-1] was efficiently resolved into a pair of optically active forms by preferential crystallization. Successive preferential crystallization of (±)-1 was experimented at 15 °C under stirring in acetone, and (+)- and (−)-1 with optical purity of 68–85% were obtained. The racemization of (−)-1 proceeded smoothly in the presence of triethylamine to give (±)-1 which was reusable for the preferential crystallization procedure. A potent antipseudomonal cephalosporin M-14659 (2) was prepared from (+)-1.
  • Yuzuru Masuda, Masayuki Hoshi, Akira Arase
    1992 Volume 65 Issue 12 Pages 3294-3299
    Published: 1992
    Released: July 29, 2006
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    3-Chloro-1-iodo-1-propyne is smoothly hydroborated with dialkylboranes, giving (Z)-(3-chloro-1-iodo-1-propenyl)dialkylboranes exclusively. Subsequent treatment of the hydroboration mixture with sodium methoxide or aqueous sodium hydroxide results in migration of two alkyl groups from the boron atom to the α-alkenyl carbon atom to provide dialkylated allylboranes, which are protonolyzed with methanol or water to produce 1,1-dialkyl-1-propenes. Oxidation of the allylboranes with alkaline hydrogen peroxide prior to protonolysis gives 1,1-dialkyl-2-propen-1-ols. Treatment of (Z)-(3-chloro-1-iodo-1-propenyl)dicyclohexylborane with Grignard reagents, followed by protonolysis with acetic acid, provides 3-alkyl-3-cyclohexyl-1-propenes in which the alkyl group is derived from Grignard reagent.
  • Yoshihisa Tsukamoto, Kazuo Sato, Takao Kinoto, Toshiaki Yanai
    1992 Volume 65 Issue 12 Pages 3300-3307
    Published: 1992
    Released: July 29, 2006
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    Introduction of a hydroxyl group to milbemycin nucleus was examined. Starting from 5-oxo-5-deoxymilbemycins, 13β-hydroxy-5-oxo-5-deoxymilbemycins were obtained stereo- and regioselectively by selenium dioxide oxidation in formic acid and subsequent acidic hydrolysis. The stereochemistry of the hydroxyl group was elucidated by 1H NMR study.
  • Shin-ichi Fukuzawa, Shizuyoshi Sakai
    1992 Volume 65 Issue 12 Pages 3308-3314
    Published: 1992
    Released: July 29, 2006
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    Tetraallyllanthanoid ate complex (1), which was readily prepared in situ from tetraallyltin, lanthanoid trichloride, and butyllithium in tetrahydrofuran (THF), reacts smoothly with α-enones (311) with a high degree of 1,2-regioselectivity (1,2 : 1,4 = >99 : 1) to give 1,5-diene-3-ols in good to excellent yields. The mechanistic study with 4,4-(ethylenedioxy)-2,6-dimethyl-2,5-cyclohexadienone (29) as a probe suggests that single electron transfer (SET) may be involved in this carbonyl allylation reaction with 1. Allylative ring opening of styrene oxide with 1 occurs at the more subsituted carbon (α-attack) in higher selectivity (α : β = 85 : 15) than with allyllithium and allylmagnesium bromide in diethyl ether. The complex 1 reacts with 3,4-epoxy-1-butene (35) in diethyl ether predominantly at the most substituted carbon of the oxirane to give 3-hydroxymethyl-1,5-hexadiene (36) together with 1,6-heptadien-3-ol (37), (E) and (Z)-2,6-heptadienols (38) (36 : 37 : 38 = 87 : 9 : 4)
  • Xiaolan Shi, Toshikazu Ibata, Hiroyuki Suga, Kiyoshi Matsumoto
    1992 Volume 65 Issue 12 Pages 3315-3321
    Published: 1992
    Released: July 29, 2006
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    The reaction of 5-alkoxythiazoles with equimolar amount of 4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione (PTAD) in an acetonitrile solution at room temperature gave the corresponding O-alkyl 6,7-dihydro-5,7-dioxo-6-phenyl-1H,5H-[1,2,4]triazolo[1,2-a] [1,2,4]triazole-1-carbothioate in high yields. The reaction was assumed to proceed through stepwise addition of PTAD toward thiazole accompanying thiazole ring opening. Diethyl azodicarboxylate also gave 2,3-dihydro-1H-1,2,4-triazole derivatives in moderate yields. High pressure improved the yields a little. On the other hand, the reaction of diethyl oxomalonate in the presence of tin tetrachloride with 4-unsubstituted thiazoles did not give an adduct of similar type but gave diethyl 2-hydroxy-2-(4-thiazolyl)malonate through the usual electrophilic substitution reaction of thiazole at C-4.
  • Atsuhiro Osuka, Yoshiya Ikawa, Kazuhiro Maruyama
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3322-3330
    Published: 1992
    Released: July 29, 2006
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    Vinylogous Vilsmeier formylation of nickel(II) 5,15-di-p-tolyl-octaethylporphyrin gave the corresponding meso-(2-formylvinyl)porphyrin, which, on treatment with trifluoroacetic acid, provided the corresponding benzochlorin derivative. In the case of the copper(II) complex, Lewis acid such as BF3·Et2O and SnCl4 catalyzed the cyclization to the benzochlorin without demetallation. Similar vinylogous Vilsmeier formylation of the nickel(II) and copper(II) complexes of 5-p-tolyloctaethylporphyrin resulted in the selective formation of 5-p-tolyl-10-(2-formylvinyl)porphyrin. Subsequent cyclization of these metal complexes took place with marked different regioselectivity; the nickel(II) complex favors the cyclization at near the 5-p-tolyl substituent, while the copper(II) complex favors the cyclization at the opposite site. Application of these synthetic methods to the 4,4′-biphenylylene-bridged diporphyrin led to the synthesis of porphyrin–benzochlorin heterodimer and benzochlorin homodimer. The steady-state fluorescence spectrum of free base form of the heterodimer suggested the intramolecular singlet excitation energy transfer from the porphyrin to the benzochlorin.
  • Mitsuaki Goto, Junzo Sunamoto
    1992 Volume 65 Issue 12 Pages 3331-3334
    Published: 1992
    Released: July 29, 2006
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    Membrane dynamics of egg yolk phosphatidylcholine (egg PC) lipid bilayer which contains human glycophorin with an artificial boundary lipid, 1,2-dimyristoylamido-1,2-deoxyphosphatidylcholine (DDPC), were investigated by ESR spin probe technique. 2-Tridecyl-2-(4-hydroxy-4-oxoundecyl)-4,4-dimethyl-3-oxazolidinyloxy (5-NS), 2-octyl-2-(7-ethoxy-7-oxoheptyl)-4,4-dimethyl-3-oxazolidinyloxy (8-ENP), and 2-hexyl-2-(11-methoxy-11-oxoundecyl)-4,4-dimethyl-3-oxazolidinyloxy (12-MNS) were used as the spin probe to measure the fluidity in different regions and depths of the lipid bilayer membrane. Studies on lipid bilayer containing 5-NS revealed that the reconstitution of glycophorin to egg PC bilayer slightly decreased the membrane fluidity in the vicinity of membrane surface. Further addition of DDPC to this liposome brought about further decrease in the fluidity of this region. Liposomes containing 12-MNS revealed, however, that the addition of glycophorin had an opposite effect on the deep hydrophobic domain of the membrane by increasing the fluidity and the addition of DDPC to the liposome makes this domain less fluid. Corresponding changes were observed in the energy of activation for the rotation of 12-MNS during each case.
  • Toshio Eiki, Shin-ichi Negishi, Waichiro Tagaki, Mitsunori Izumi, Kazu ...
    1992 Volume 65 Issue 12 Pages 3335-3342
    Published: 1992
    Released: July 29, 2006
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    It was reported previously that metal ions such as Mg2+, Cr3+, Cu2+, Mn2+, and Ca2+ catalyzed selective P–O bond cleavage of P–O–S linkage in the methanolysis of phenyl phosphatosulfate (PPS), and in contrast, metal ions such as Zn2+, Fe3+, Al3+, and Be2+ promoted selective S–O bond cleavage.1) We have now found that Cd2+ catalyzes mixed cleavage of P–O and S–O bond in a ratio of 58 and 42%, respectively, in the methanolysis of PPS. The value of second-order-rate constant (k2) for Cd2+ catalyzed P–O bond cleavage satisfied the correlation between values of k2(P–O) and ionic radii of metal ions, but that for Cd2+ catalyzed S–O bond cleavage was considerably smaller than that expected from the rate correlation. The presence of chloride ion reduced the rate of Cd2+ catalyzed P–O bond cleavage to about one tenth of that in the absence of chloride ion, but inhibited completely the S–O bond cleavage catalyzed by Cd2+ or Zn2+. The kinetic studies suggested that the inhibition by chloride ion occurred with the formation of ternary (PPS·Cd2+·Cl) and tetramerous (PPS·Zn2+·2Cl) complexes of substrate, metal ion and chloride ion. On the basis of these results the selectivity of the metal ion in the site of bond cleavage was discussed.
  • Akihiko Ishii, Meng-Xin Ding, Kiyoto Maeda, Juzo Nakayama, Masamatsu H ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3343-3349
    Published: 1992
    Released: July 29, 2006
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    Oxidation of 2,2,3,3-tetramethyl-1,4-diphenyl-5,6-dithiabicyclo[2.1.1]hexane with m-chloroperbenzoic acid gives two isomeric endo- (4a) and exo-sulfoxides (4b), three S,S′-dioxides (endo, exo-5a, exo, exo-5b, and endo, endo-5c), and an S,S,S′-trioxide (6). The relative reactivity to further oxidation is 4b >> 4a and 5b > 5a, which suggests that the attractive 1,3-transannular interaction operative in 1,3-dithietane part of 4a and 5a decreases the reactivity of 4a and 5a. 4b isomerizes to 4a on standing over silica gel at room temperature and also 5b is converted to 5a on heating. Heating 6 in refluxing toluene yields 3,3,4,4-tetramethyl-1,2-diphenylcyclobutene, 2,5-dimethyl-3,4-diphenyl-2,4-hexadiene, and the isomeric trioxide.
  • Kentaro Iwasaki, Akito Ugawa, Atsushi Kawamoto, Yoshiro Yamashita, Kyu ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3350-3357
    Published: 1992
    Released: July 29, 2006
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    The charge-transfer complex between naphthaceno[5,6-cd:11,12-cd′]bis[1,2]diselenole (TSeN) and 4,8-bis(dicyanomethylene)-4H,8H-benzo[1,2-c:4,5-c′]bis[1,2,5]thiadiazole (BTDA-TCNQ) is found to show at least three different types of crystal modifications; insulating Type-I has a (1 : 1 : 1) ratio containing solvent molecules (chlorobenzene), metallic Type-II has a (1 : 1) stoichiometry, and semiconductive Type-III is conjectured to have a (1 : 2) or (2 : 1) stoichiometry. The crystal structures of Type-I and Type-II were determined by a single-crystal X-ray diffraction method. Type-I comprises mixed-stack molecular columns, and Type-II segregated-stack molecular columns. In both types the neighboring columns are linked along short molecular axes by two Se···N contacts that are shorter than the corresponding van der Waals contact. In the Type-II crystal, there are other short distances between TSeN and BTDA-TCNQ in the direction of the long molecular axes. From the C=C bond length in the C=C(CN)2 group of BTDA-TCNQ, the degrees of charge transfer of these molecular complexes were estimated as 0.2 ± 0.3 in Type-I and 0.9 ± 0.2 in Type-II.
  • Yukie Mori, Masako Sasaki, Chie Daian, Sachiko Yamada, Koko Maeda
    1992 Volume 65 Issue 12 Pages 3358-3361
    Published: 1992
    Released: July 29, 2006
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    5,10,15,20-Tetrakis(4-aminophenyl)porphyrin [T(p-NH2)PP] exhibited thermochromism in 2-methyltetrahydrofuran. In the electronic spectrum at 77 K four Q bands largely shifted to longer wavelength and relative intensities changed. The electronic spectrum of T(p-NH2)PP was also influenced by the nature of solvents. In strong hydrogen-bond accepting solvents Q bands were red-shifted and the resulting spectrum resembles that recorded at low temperature. Based on the solvent effect and substituent effects, the thermochromism of T(p-NH2)PP can be attributed to enhancement of hydrogen-bonds between p-NH2 group and solvent molecules at lower temperature, which causes increase of effective electron-donating ability of p-NH2 group. In alcoholic solvents T(p-NH2)PP and T(p-OH)PP showed another type of temperature dependence of absorption spectra.
  • Akio Yuchi, Hiroshi Murakami, Motoo Shiro, Hiroko Wada, Genkichi Nakag ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3362-3373
    Published: 1992
    Released: July 29, 2006
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    Nickel(II) has been extracted with 2-methyl-8-quinolinol (Hmq) into chloroform under the following conditions: CNi = 2 × 10−5–4 × 10−3; CHmq = 7.5 × 10−3–4.8 × 10−1 mol dm−3; supporting electrolyte: 0.1 mol dm−3 NaClO4 or Na2SO4; −log [H+] = 4.5–9. An equilibrium analysis has demonstrated that neutral species, (Ni2(mq)4)o and (Ni3(mq)6)o, are responsible for extraction from sulfate solutions, whereas ion-pair species, ([Ni3H(mq)6]ClO4)o and ([Ni2H3(mq)6]ClO4)o, are predominant from perchlorate solutions. The dimeric structure of (Ni2(mq)4)o is cleaved stoichiometrically along with adduct formation upon adding 1,10-phenanthroline, while being converted to (NiH(mq)3)o and/or (Ni2H2(mq)6)o at high concentrations of Hmq. X-ray crystallographic studies show that the complexes, [Ni3(mq)6]·2C2H5OH and [Ni3H(mq)6]ClO4·C2H5OH, have discrete bent-trimeric structures, and maintain all the nickel atoms octahedral by two μ- and two μ3-bridgings at the phenolate oxygen atoms. In the [Ni2H3(mq)6]ClO4 complex, each nickel atom is surrounded by three ligands in a fac configuration and two octahedrons are connected by three hydrogen bondings. All the three structures in solids are discrete and possibly the same as those in organic solvents. Compared with 8-quinolinol, the methyl group of Hmq makes the coordination of the third ligand unfavorable for both neutral and ion-pair species. Bridging at the phenolate oxygen atoms yields extractable oligomeric species.
  • Kikuo Miyokawa, Setsuko Kinoshita, Takumi Etoh, Hisanobu Wakita
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3374-3377
    Published: 1992
    Released: July 29, 2006
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    The oxygen-dissociation reactions of [Co(3-X-salen)]2O2, where 3-X-salen is N,N′-ethylenebis(3-substituted salicylideneaminate) dianion, X = H (1), OCH3 (2), OC2H5 (3), NO2 (4), have been studied by means of a thermoanalytical technique. The heat of the reaction, determined by DTA, ranges from 88 (4) to 120 (2) kJ mol−1; the electron-releasing substituents tend to stabilize the Co–O2 bonding. The O2-dissociation process is best described by the first-order equation and the activation enthalpies range from 117 (4) to 145 (2) kJ mol−1 and the electron-releasing substituents increase the activation enthalpy. A kinetic compensation effect was observed, except for 3, which is the most stable of these complexes due to its small activation entropic value.
  • Takuhiro Otsuka, Akiko Sekine, Yuji Ohashi, Youkoh Kaizu
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3378-3385
    Published: 1992
    Released: July 29, 2006
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    The measurements of absorption and luminescence spectra and luminescence decay are carried out on pure crystals of Na3[Cr(ox)3xH2O (ox2− = C2O42−) (x = 5 or 4) and Li3 [Cr(ox)3yH2O (y = 6 or 5). In sodium salt, dehydration of one crystal water (x = 4) causes the luminescence intensity to be about thirty times larger and the lifetime to be about thirty times longer than those of the most hydrated crystal (x = 5) while the opposite trend is obtained in lithium salt. However, in both salts, no change of the position of luminescence maximum is observed by the dehydration of one crystal water from the most hydrated crystals. Comparing these results with X-ray crystallographic analyses shows that a crystal water located near the oxalato-oxygen atom, which is coordinated to Cr3+ ion, affects the 2Eg4A2g (all in Oh notation) relaxation of [Cr(ox)3]3− complexes in the pure crystal.
  • T. Ken Miyamoto, Yoshitsugu Suzuki, Hikaru Ichida
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3386-3397
    Published: 1992
    Released: July 29, 2006
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    A dihydroxoplatinum(II) compound, cis-[Pt(OH)2(PMe3)2nH2O (Me = methyl, n = 2–3; 1), has been characterized by 31P, 195Pt, 13C, and 1H NMR spectroscopy. The thermal stability of 1 was examined. The presence of several water molecules is required for the stabilization of 1. The solution equilibria and the reaction of 1 with aqueous hydrogen peroxide were observed by 31P NMR spectroscopy. The neutralization of 1 with several dicarboxylic acids afforded water-soluble phosphine complexes in quantitative yields. Exposure of 1 toward air gives the carbonatoplatinum(II), cis-[Pt(CO3)(PMe3)2]·2H2O. Its crystal structure determination has revealed that the carbonate anion forms four-membered ring with a platinum atom.
  • Rajendra Prasad, U. C. Agarwala
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3398-3404
    Published: 1992
    Released: July 29, 2006
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    A series of mono and binuclear cyanodithioformate (cdf) complexes with [RuIICpL2] [L = PPh3, AsPh3, SbPh3, (dppe)1/2, (dppm)1/2], exploiting its different coordination modes have been synthesized. Various physical and electrochemical methods have been used to characterize them. cdf by virtue of its vacant π* orbital introduces a low laying energy state in the compounds that facilitates Ru → cdf (dπ → π*) MLCT transition. MLCT band, upon dimerizaion shows red shift, whose magnitude depends upon site of attachment of second ruthenium moiety [, 3750 cm−1 for μ(η1–S; η1–S′) and 1010 cm−1 for μ(η1–S; η1–N) cdf complexes]. All complexes exhibit anodic oxidation peaks except binuclear μ(η1–S, η1–S′) cdf complex which exhibits reversible oxidation wave E1/2, −0.20 V vs. SCE in acetonitrite. Their spectral and electrochemical behavior are correlated with the σ, π characterstics of cdf and ruthenium moieties.
  • Shunji Kageyama, Tsutomu Tsuchiya, Sumio Umezawa, Masaya Orita
    1992 Volume 65 Issue 12 Pages 3405-3411
    Published: 1992
    Released: July 29, 2006
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    The title compounds, which proved highly antibacterial, have been prepared by selective hydrogenation of the corresponding 2,3-unsaturated compounds with LiAlH4, diisobutylaluminium hydride, or NaBH4–NiCl2 as the key steps. Further, the latter title compound was prepared effectively through the reaction of 3-O-benzylsulfonyl-5-O-(4-deoxy-4-iodomycaminosyl)-23-O-(dimethylthexylsilyl)tylonolide 9,20-bis(ethylene acetal) with Raney Ni–K2CO3 involing three steps in it.
  • Paramjeet Kaur, Gyanedra Kumar Patnaik, Ram Raghubir, Virander Singh C ...
    1992 Volume 65 Issue 12 Pages 3412-3418
    Published: 1992
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    Peptide fragments of Substance P corresponding to the C-terminal segments (6-11) and (4-11), which contain a putative β-turn, were synthesised using solution phase methodology. Analogs of Substance P were synthesised where the phenylalanine residue at position 8 was replaced by dehydrophenylalanine (ΔPhe) and the glycine residue in position 9 was replaced by alanine, valine, sarcosine (N–Me–Gly) and α-aminoisobutyric acid. In two of the analogs [8-ΔPhe, 9-Sar]–SP (4-11) (5) and [5,8-ΔPhe, 9-Aib]–SP (4-11) (7) glutamine residue at position 5 was also substituted by ΔPhe. These analogs were evaluated for their ability to cause smooth muscle contraction in guinea pig ileum preparation (in vitro) and for hypotensive activity (in vivo) in female rats anesthetized with urethane. In the hexapeptide series [8-ΔPhe]–SP (6-11) (1) and [8-ΔPhe, 9-Sar]–SP (6-11) (4) showed significant activity in both the assays. Octapeptide [5,8-ΔPhe, 9-Sar]–SP (4-11) (5) with ΔPhe residue in positions 5 and 8 and sarcosine in position 9 was found to be the most potent analog both in vitro and in vivo systems.
  • Mohamed Gaber Marei, Dalia Mahmoud Aly, Morcos Michael Mishrikey
    1992 Volume 65 Issue 12 Pages 3419-3422
    Published: 1992
    Released: July 29, 2006
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    5-Aryl-2-phenylpyrazolo[1,5-c]pyrimidine-7(6H)-thiones have been synthesized by the reaction of 1,5-diaryl-4-pentyne-1,3-diones with thiosemicarbazide and their reactions were studied. The pyrazolopyrimidinethiones give with certain electrophiles the respective 3-substituted 7-thiones. Their oxidation affords the corresponding disulfide. Moreover, they can be converted to the corresponding pyrazolopyrimidinones on reaction with alkaline hydrogen peroxide. The structure of the above compounds was confirmed from their spectral characteristics.
  • Yun Chen, Ming-Tang Shiao
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3423-3429
    Published: 1992
    Released: July 29, 2006
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    A monoamide derived from (−)-anti head-to-head coumarin dimer [(−)-CD] with propylamine has been successfully bonded to silica gel (Lichrospher 100 NH2: Merck) through amide linkage to prepare CSP-1. Another monoamide derivative CSP-2 was prepared by direct nucleophilic opening of one lactone ring of (−)-CD by Lichospher 100 NH2, followed by hydrolysis of the other lactone. CSP-1 and CSP-2 showed high enantioselectivity to trans-stilbene oxide with separation factors (α) at 2.42 and 2.46, respectively, and the (−)-isomer eluted first. The capacity factor (k′) and α decrease with increasing polarity of the eluent (hexane/2-propanol), indicating that hydrogen bonding plays important role in chiral recognition. CSP-3, obtained by ligand exchange of CSP-2 with CuSO4(aq), resolved DL-tryptophan, DL-tyrosine, and DL-phenylalanine (α = kD′/kL′ = 1.14–1.33), which all contain aromatic chromophore. The stability difference of the ternary complexes formed with D-isomer and L-isomer is explained by steric hindrance and aromatic π-π interactions.
  • Yasuzo Sakai, Katsumi Osada, Fujio Takahashi, Susumu Takada
    1992 Volume 65 Issue 12 Pages 3430-3433
    Published: 1992
    Released: July 29, 2006
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    Glucoamylase was immobilized by glutaraldehyde combined with albumin coated on the surface of a powder of SrFe2O4 as the carrier. This carrier obtained a magnetically anisotropic property under exposure to a static magnetic field. The carrier was able to oscillate and rotate in an alternating magnetic field. The rate of hydrolysis of starch to glucose increased in the alternating magnetic field. This is because the transport of molecules may be facilitated through the interface of the carrier surface and solution by oscillation.
  • Shigenobu Kawakami, Takeshi Kanaguchi, Hiroshi Tagami, Masahiro Nakada ...
    1992 Volume 65 Issue 12 Pages 3434-3438
    Published: 1992
    Released: July 29, 2006
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    The thermal reactions of toluene or methane in a Clusius–Dickel type thermal diffusion column was investigated in the temperature range from 1300 K to 1470 K under atmospheric pressure from the viewpoint of the effect of coexistent gases to clarify the effect of thermal diffusion on the reactions. The addition of hydrogen accelerated the hydrogenolysis of toluene resulting in the high selectivity of benzene. Contrarily, by the addition of either helium or nitrogen, the reactions were retarded. On the other hand, the reactions of methane were promoted by the addition of nitrogen, and retarded by the addition of helium. This difference of the effect of coexistent gases of helium and nitrogen shows that the partial separation of reaction mixture due to thermal diffusion and convection actually occurs and has a great influence on the reaction results in a Clusius–Dickel type thermal diffusion column.
  • Katsuya Maruo, Yuji Wada, Shozo Yanagida
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3439-3449
    Published: 1992
    Released: July 29, 2006
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    Perfluorination of oligo(p-phenylene)s (OPP-n), biphenyl(OPP-2) to p-quaterphenyl (OPP-4), induces various changes in the spectral and physical characteristics of OPP-n; a hypsochromic shift of their absorption spectra, a decrease in their fluorescence quantum yields, an increase in their fluorescence lifetimes, and a positive shift of their oxidation potentials. The resulting perfluorinated oligo(p-phenylene)s (F-OPP-n, n = 3 and 4) shows photocatalytic activities for the photoreduction of water and for the photooxidation of benzene to phenol. Irradiation of an aqueous methanol solution of F-OPP-3 with triethylamine as an electron donor, and noble metal colloid as an electron mediator at λ > 290 nm, leads to H2 evolution, although photodefluorination through F-OPP-3−• inevitably occurs to an appreciable extent. A similar irradiation of an aqueous acetonitrile solution with O2 and benzene induces the oxidation of benzene and water, yielding almost equal quantities of phenol and H2O2 without any accompanying degradation of F-OPP-3.
  • Abdel-Aziz Ahmed Said
    1992 Volume 65 Issue 12 Pages 3450-3454
    Published: 1992
    Released: July 29, 2006
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    Molybdenum oxide catalysts doped or mixed with (1–50) mol% Fe3+ ions were prepared. The structure of the original samples and calcined at 400 °C were characterized using DTA, X-ray diffraction, and IR spectra. The measurements of the electrical conductivity of calcined samples with and without isopropyl alcohol revealed that the conductance increases on increasing the content of Fe3+ ions up to 50 mol%. The activation energies of charge carriers were determined in presence and absence of alcohol. The catalytic dehydration of isopropyl alcohol was carried out at 250 °C using flow system. The results obtained showed that the doped or mixed catalysts are active and selective towards propene formation. However, the catalyst containing 40 mol% Fe3+ ions exhibited the highest activity and selectivity. Correlations were attempted between the catalyst composition and their electronic and catalytic properties. Probable mechanism for the dehydration process is proposed in terms of surface active sites.
  • Pradyot Kumar Chowdhury
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3455-3461
    Published: 1992
    Released: July 29, 2006
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    Real time observation of retro-Diels–Alder dissociation of decafluorocyclohexene into tetrafluoroethylene and hexafluorobutadiene induced by transversely excited atmospheric pulsed CO2 laser is reported. The formation rate and the red-shifted absorption spectra of nascent hexafluorobutadiene suggest substantial internal energy incorporation, which appears to be sufficient for its undergoing electrocyclic transformation to hexafluorocyclobutene at a rate corresponding to the decay kinetics. When the above IR multiphoton dissociation of decafluorocyclohexene occurs in presence of oxygen, UV light emission due to COF2* is observed.
  • Ashis Bhattacharjee, Biswanath Mallik
    1992 Volume 65 Issue 12 Pages 3462-3469
    Published: 1992
    Released: July 29, 2006
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    The change in dark conductivity of some ferrocene derivatives on adsorption of some organic solvent has been studied in sandwich cell configurations at different cell temperatures. Appreciable enhancements in the dark conductivity are observed. Such enhancement depends on the amount of adsorbed vapor, cell temperature as well as the chemical nature of the adsorbate. The sensitivity towards a vapor is also found to vary depending on the nature of the substituent groups in the ferrocene ring. Both the adsorption and desorption rates follow the modified Roginsky–Zeldovich equation. The temperature dependence and the nature of the solid-vapor interaction have been deduced from the rate data analysis.
  • Bijan Das, Dilip K. Hazra
    1992 Volume 65 Issue 12 Pages 3470-3476
    Published: 1992
    Released: July 29, 2006
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    Electrical conductances, relative viscosities, and apparent molal adiabatic compressibilities of solutions of some symmetrical tetraalkylammonium perchlorates in 2-methoxyethanol (ME) have been reported. The conductance data have been analyzed by the 1978 Fuoss conductance equation and the viscosity data by the Jones–Dole equation for associated electrolytes. The ionic contribution to the limiting equivalent conductance, viscosity B coefficient and other thermodynamic parameters have been determined using the “reference electrolyte” method. The viscosity data show that the tetraalkylammonium ions are poorly solvated and behave as structure-breakers in 2-methoxyethanol. Analysis of the conductance as well as the compressibility data reveals the existence of strong ion-ion interactions in this solvent medium. The compressibility data also indicate the electrostriction of solvent molecules around the tetraethylammonium ion, while for the larger tetraalkylammonium ions they are accommodated inside the space between the coiled alkyl chains attached to the nitrogen atom.
  • Robert Kingsford-Adaboh, Setsuo Kashino
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3477-3479
    Published: 1992
    Released: July 29, 2006
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    The crystal structure of a derivative of β-D-ribofuranose has been determined by X-ray diffraction method in order to characterize the molecular conformation. The phase angle P and the degree of puckering τm of the sugar ring are −7.6 and 34.3° respectively. The ring shows C(3′)-endo-C(2′)-exo puckering () as found in sucrose and 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose. The furanoid carbons C(1′), C(2′), and C(3′) adopt the cis conformation with the carbonyl oxygens of their corresponding side chains. This conformation is favored by intramolecular C–H···O=C interactions. All carbonyl oxygens also participate in intermolecular C–H···O=C interactions in the crystal.
  • Takayuki Saitoh, Yoshio Nakamura, Shigezo Shimokawa
    1992 Volume 65 Issue 12 Pages 3480-3481
    Published: 1992
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    The diffusion coefficients of benzene in a pressurized vessel has been measured up to above the gas–liquid critical temperatures. The observed diffusion coefficients are compared with the calculated values from a simple hard-sphere approach.
  • Mamoru Sato, Yukiteru Katsube, Tadamasa Terai, Jun’ichi Katakawa ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 12 Pages 3482-3484
    Published: 1992
    Released: July 29, 2006
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    The three dimensional structure of 1,5-seco-grayanotoxin-1,3,6,14,16-pentaacetate has been determined by X-ray diffraction at room temperature. The monoclinic structure was refined by the full matrix least-squares method to a final R = 0.037 for 2269 independent reflections. The molecule has a tricyclic structure that consists of ten-, six-, and five-membered rings. The absolute configuration at C1 atom was determined as S on the basis of internal comparison with the absolute structure of 1,5-seco-grayanotoxin-1(R),3,6,14,16-pentaacetate.
  • Hiroshi Kawamoto, Wataru Ishida, Kin-ichi Tsunoda, Hideo Akaiwa
    1992 Volume 65 Issue 12 Pages 3485-3486
    Published: 1992
    Released: July 29, 2006
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    Hourly variation of copper(II) complexing capacity (CuCC) of water samples from the Kiryu River in Gunma prefecture was investigated. From the stand point of complexing capacity, the present water samples could be classified into two types, that is, the daytime type and the nighttime one. Water sampled belonging to the former type contained some ligands derived from human activity, and naturally occurring ligands were mainly found in water samples belonging to the latter. The estimation of stability constant for copper(II) complex in water samples was also carried out on the basis of a single ligand model.
  • Tamotsu Fujisawa, Yoshiyuki Okumura, Kazuhisa Morita, Yutaka Ukaji
    1992 Volume 65 Issue 12 Pages 3487-3489
    Published: 1992
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    The intramolecular alkylation reaction of enolates of t-butyl α-alkoxy carboxylates in THF–HMPA proceeded stereoselectively to afford 2,2,6-trisubstituted tetrahydropyrans with high cis-selectivity.
  • Yohji Nakatsuji, Toshinori Inoue, Araki Masuyama, Mitsuo Okahara
    1992 Volume 65 Issue 12 Pages 3490-3492
    Published: 1992
    Released: July 29, 2006
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    A new type of macrobicyclic compound, which was prepared by the reaction of 2,9-bis[(ethylamino)methyl]-15-crown-5 with sebacoyl dichloride, has shown a selective complexation property toward K+ and Ba2+ cations based on data obtained with potentiometric titration and solvent extraction. This finding was reasonably explained by considering the cooperative binding of the amide moieties and the crown ring. The coordination direction of the carbonyl oxygens was found to markedly affect its complexation property by comparing its complexing ability with those of lariat ethers having one or two amide side arms.
  • Tsunenori Nozawa, Katsunori Ohtomo, Naohiro Takeshita, Yumi Morishita, ...
    1992 Volume 65 Issue 12 Pages 3493-3494
    Published: 1992
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    Six bacteriochlorophyll (BChl) d homologues were isolated from Chlorobium limicola. The absorption spectral profiles in hexane–dichloromethane and the solvent effects indicate that the aggregation property of the BChl d’s strongly depend on the nature of the peripheral substituents.
  • Tsuyoshi Ogiku, Shin-ichi Yoshida, Tooru Kuroda, Masami Takahashi, Hir ...
    1992 Volume 65 Issue 12 Pages 3495-3497
    Published: 1992
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    (±)-Isopodophyllotoxone and (±)-picropodophyllone were synthesized stereoselectively from the O-(t-butyldimethylsilyl) cyanohydrins (3a) in good yields. This new method was successfully applied to the syntheses of a variety of lignans of the aryltetralin series.
  • Tadashi Hasegawa, Kumiko Takashima, Hiromu Aoyama, Michikazu Yoshioka
    1992 Volume 65 Issue 12 Pages 3498-3500
    Published: 1992
    Released: July 29, 2006
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    Upon irradiation, 2-benzyloxyethyl and 2-methoxyethyl 2-benzoylbenzoate underwent photocyclization through remote θ-hydrogen abstraction, though 2-benzyloxyethyl 3-benzoylacrylate underwent only cis-trans photoisomerization and 2-benzyloxyethyl 3-benzoylpropionate gave an intractable mixture. Conformational restriction is an important factor for remote hydrogen abstraction.
  • Keiji Maruoka, Arnel B. Concepcion, Hisashi Yamamoto
    1992 Volume 65 Issue 12 Pages 3501-3503
    Published: 1992
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    The asymmetric Diels–Alder reaction of cyclopentadiene and methyl acrylate has been effected with high enantioselectivity under the influences of catalytic amounts of chiral organoaluminum reagents.
  • Yoshihiro Matano, Masamichi Kinoshita, Hitomi Suzuki
    1992 Volume 65 Issue 12 Pages 3504-3506
    Published: 1992
    Released: July 29, 2006
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    Bismuth trichloride reacts smoothly with mesityl- and 2,4,6-triisopropylphenylmagnesium bromides in boiling tetrahydrofuran to form the corresponding triarylbismuthines in good yields, while a similar reaction with 2,4,6-triisopropylphenylmagnesium bromide halts at diarylation stage, giving chlorobis(2,4,6-triisopropylphenyl)bismuthine as the sole product. Several crowded alkyl-, alkenyl-, and alkyn-yldiarylbismuthines have been prepared from the above diarychlorobismuthine through the reaction with an appropriate organolithium reagent.
  • Shuddhodan Prasad Mishra, Md. Rakib-Uz-Zaman
    1992 Volume 65 Issue 12 Pages 3507-3508
    Published: 1992
    Released: July 29, 2006
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    (n, γ) Activation of dibromomethane, tribromomethane, 1-bromonaphthalene, 2-bromophenol and 2-bromopropionic acid has been studied in liquid phase by Charge Plate Technique. A (Ra–Be) neutron source of 300 mCi having an integral flux of 3.2 × 106 n cm−2 s−1 was used for the production of energetic bromine species. Both anionic and cationic charged species have been collected on charged plates for the targets used except in 2-bromopropionic acid where cathode activity was found nil. This result is unique and never observed before for pure liquid bromocompounds using charge plate collection experiments.
  • Mohamed Gaber Marei, Moneim El-Ghanam
    1992 Volume 65 Issue 12 Pages 3509-3511
    Published: 1992
    Released: July 29, 2006
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    The synthesis of the title acetylenic β-diketones which are starting materials to prepare cyclic and bicyclic compounds is described.
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