Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 65 , Issue 5
Showing 1-44 articles out of 44 articles from the selected issue
  • Nobuko Kanehisa, Yasushi Kai, Nobutami Kasai, Hajime Yasuda, Yuushou N ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1197-1201
    Published: 1992
    Released: July 14, 2006
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    As a series of structural chemistry of early transition metal-phenoxides, the molecular structures of WCl5[2,6-(CH3)2C6H3O] (1) and WCl4[2,6-(CH3)2C6H3O]2 (2) have been determined by an X-ray diffraction method. Crystal data: 1; orthorhombic, space group Cmcm, a = 7.979 (3), b = 17.094 (4), c = 12.536 (2) Å, V = 1709.7 (8) Å3, Z = 4, Dc = 2.412 g cm−3, 2; monoclinic, space group C2/m, a = 17.615 (4), b = 7.188 (2), c = 8.396 (2) Å, β = 119.93 (2)°, V = 921.3 (4) Å3, Z = 2, Dc = 2.047 g cm−3. Complexes 1 and 2 have a molecular symmetry of C2v (mm) and C2h (2/m), respectively; the W–O–C(phenoxy) angles are 180° in 1 and 179° in 2. These are the first examples with a straight W–O–C(phenoxy) bond. By retrieval from the Cambridge Crystallographic Database the W–O–C(phenoxy) angles have been revealed to cover a wide range of 117–180°, which correlated with the W–O distance in the hyperbolic mode.
  • Akihiko Kudo, Akira Tanaka, Kazunari Domen, Ken-ichi Maruya, Takaharu ...
    1992 Volume 65 Issue 5 Pages 1202-1206
    Published: 1992
    Released: July 14, 2006
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    Niobic acid powders, H3NbO4 and H8Nb6O19, obtained by hydrolysis from aqueous potassium niobate (K3NbO4 and K8Nb6O19) solutions with sulfuric acid showed a high photocatalytic activity for hydrogen evolution from an aqueous solution including methanol as a sacrificial reagent without supporting any other materials, such as Pt (quantum yield; ca. 10% at 330 nm). The activity depended on the calcination temperature. H3NbO4 powder dried at 380 K was the most active one. As the calcination temperature was increased, the H3NbO4 photocatalyst was transformed into HNbO3 (or Nb2O5·H2O) and Nb2O5 by dehydration. The BET surface area and the band gap of the powder decreased with the phase transformation. It is concluded that both the surface area and hydrated state strongly affect the activity for sacrificial hydrogen evolution on the niobic acid photocatalysts.
  • Sadakatsu Nishikawa, Masayuki Ueda
    1992 Volume 65 Issue 5 Pages 1207-1213
    Published: 1992
    Released: July 14, 2006
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    The ultrasonic absorption coefficients in aqueous solutions of 3-methoxy-1-butanol and 1-methoxy-2-butanol have been measured in the frequency range from 8.5 to 220 MHz at 25 °C. One process associated with a single-relaxational ultrasonic absorption has been found in both solutions. From the concentration dependencies of the relaxation frequency and the amplitude of ultrasonic relaxation, the cause of the relaxation has been attributed to a perturbation of an equilibrium associated with interaction between the solute and the solvent. The rate and thermodynamic parameters have been determined for the reaction and the effect of the isomeric alcohols on water structure has been considered based on these parameters. As results, both alcohols have been found to act as a water structure promoter. The effect of the methoxyl group in the alcohol molecules on the water structure has been speculated to break the water hydrogen bonds, i.e. to act as a structure breaker for water. Also, the results for solutions of other isomers, 2-propoxyethanol and 3-ethoxy-1-propanol, and that of a similar structure, 2-allyloxyethanol, have been compared with those obtained in this study. The effects of substituents in alcohol molecules have been discussed in relation to the water structure. They have also been considered from a comparison with the hydrophobic ability of the alcohols estimated from the concentration dependence of the apparent molar compressibility, along with the result from an ethanol aqueous solution. Both estimations from ultrasonic absorption and compressibility have provided a consistent interpretation for the effects on the water structure. From these present results regarding ultrasonic absorption, it has been speculated that the large ultrasonic absorptions observed near critical points in some alcohol solutions are superimposed with the usual Debye type relaxations.
  • Tadashi Tokii, Naohiko Hamamura, Michio Nakashima, Yoneichiro Muto
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1214-1219
    Published: 1992
    Released: July 14, 2006
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    Novel μ-carboxylato-μ-hydroxo-bridged binuclear copper(II) complexes with 1,10-phenanthroline, [Cu2(OH)(RCOO)(phen)2]X2·H2O (where R = H, X = BF4 (1); R = CH3, X = NO3 (2); R = C2H5, X = NO3 (3)) were prepared and characterized by elemental analyses, electronic spectra, magnetic susceptibilities, and X-ray structure analysis. The magnetic susceptibility data conform to the usual dimer equation. The −2J values are −109 cm−1 for 1, −111 cm−1 for 2, and −109 cm−1 for 3, indicating that a strong ferromagnetic spin coupling exists in these complexes. The crystal structures of 2 and 3 were determined by the single-crystal X-ray diffraction method. The crystallographic data are: Compound 2, monoclinic, P21/n, a = 8.107 (10), b = 18.554 (9), c = 18.616 (7) Å, β = 99.14 (6)°, V = 2765 (6) Å3, Z = 4, R = 0.045 for 3274 observed unique reflections; compound 3, monoclinic, P21/n, a = 7.981 (10), b = 18.352 (8), c = 19.247 (8) Å, β = 97.98 (7)°, V = 2792 (4) Å3, Z = 4, R = 0.047 for 3220 reflections. These complexes have very novel roof-shaped binuclear units with dihedral angles (122.8° for 2 and 122.7 ° for 3) observed between two basal planes of CuO2N2. These small dihedral angles are mainly attributed to the strong ferromagnetic exchange interaction in the present complexes.
  • Koji Araki, Masahiro Fuse, Noriyuki Kishii, Shinsaku Shiraishi
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1220-1224
    Published: 1992
    Released: July 14, 2006
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    Spectroscopic, photocehmical, and electrochemical properties of a series of the Ru(II) complexes 14, Ru(dabp)3−n(bpy)n(BF4)2 (n = 0, 1, 2, and 3, respectively, dabp = 6,6′-diamino-2,2′-bipyridine, and bpy = 2,2′-bipyridine) having different degree of interligand steric strain caused by amino substituents of dabp were studied. Their metal-to-ligand charge transfer bands and oxidation-reduction potentials of a Ru(II)/Ru(III) couple were not so much different from each other. Though the complex 3 showed weak emission at around 630 nm (φ = 6 × 10−4), no emission of light was observed for the complexes 1 and 2. These properties and photoanation of the complexes 1 and 3 were discussed in terms of the steric and electronic effects of the amino substituents.
  • Satoru Nakashima, Hiroaki Ohya-Nishiguchi, Noboru Hirota, Sei Tsuboyam ...
    1992 Volume 65 Issue 5 Pages 1225-1232
    Published: 1992
    Released: July 14, 2006
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    The reactions of two CoIII-tetramine (N4) complexes, cis-α-Dichloro(triethylenetetramine)cobalt(III) chloride = [CoIIICl2(trien)]Cl (1) and aquabromo[(2R, 5R, 8R, 11R)-2,5,8,11-tetraethyl-1,4,7,10-tetraazacyclododecane]cobalt(III) bromide = [CoIIIBr(Et4[12]-aneN4)(H2O)]Br2 (2) with 3,5-di-t-butylcatechol (H2dbc) have been examined by visible, NMR and ESR spectroscopies to elucidate the mechanism of the activation and the oxygenation of catechol by the complex formation. The reactions proceeded in a mixed solvent (H2O : MeOH = 1 : 1) at 50 °C in the presence and absence of dioxygen. NMR showed that the complexes react with E2dbc and dioxygen, and yield oxidatively cleavaged products. ESR measurements detected a CoIII-semiquinone (dbsq) radical and a high-spin CoII complex, regardless of the presence of dioxygen. Especially in the case of 1, the magnetic moment of the complex isolated from the anaerobic reaction solution, exhibited that there exists an antiferromagnetic spin-coupling between the high-spin (S= 3/2) CoII ion and the semiquinone radical in the complex. These results show that two species detected by ESR are in equilibrium with a high-spin CoII-dbsq binary complex formed by intramolecular electron transfer. It is conclusively clarified that the one-electron-transferred intermediate [CoII(N4)dbsq]+ is the activated intermediate, which introduces dioxygen into the semiquinone moiety.
  • Hideaki Kanno, Masanori Tomita, Shunji Utsuno, Junnosuke Fujita
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1233-1239
    Published: 1992
    Released: July 14, 2006
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    Two new chromium(III) complexes of the type, [Cr(L)(bpdo)2]+ (L = oxalate (ox2−) or malonate (mal2−) ion), where bpdo denotes 2,2′-bipyridine N,N′-dioxide, were prepared and resolved into a pair of enantiomers by use of Ag2[Sb2{(+)589-tartrate}2]. The perchlorates of these complexes were found to crystallize in the lel2 (Δ(λλ), Λ(δδ)) form. Upon dissolution in water, the complexes isomerized to the lel·ob (Δ(λδ), Λ(δλ)) form with a rapid change in absorption spectra, and then racemized (Δ Λ). Rates of the isomerization and racemization at 25 °C were 7.65 × 10−3 s−1 and 2.20 × 10−3 s−1, respectively for the ox complex, and 4.95 × 10−3 s−1 and 6.42 × 10−5 s−1 for the mal one. These rates were independent of concentrations of H+ and the free bpdo ligand, indicating an intramolecular mechanism for these reactions. The faster reactions of the ox complex than those of the mal one may be attributed to the steric effect due to the less crowded structure of the ox complex.
  • Hideyuki Kuno, Makoto Shibagaki, Kyoko Takahashi, Ichiro Honda, Hajime ...
    1992 Volume 65 Issue 5 Pages 1240-1243
    Published: 1992
    Released: July 14, 2006
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    The regioselective hydrogenation of unsaturated compounds was carried out by catalysis with platinum-zeolite coupled with an organosilicon alkoxide using a chemical vapor deposition method (CVD-modified catalyst). In hydrogenation of a mixture of 1-nonene and trans-4-nonene by this catalyst, the reaction rate of 1-nonene was much greater than that of trans-4-nonene. In particular, when diphenyldiethoxysilane was used as the coupling reagent on the platinum–zeolite, excellent selectivity was produced. Further, it was elucidated that the terminal carbon–carbon double bonds are preferentially hydrogenated in the case of some compounds possessing more than one carbon–carbon double bond.
  • Akikazu Kakehi, Suketaka Ito, Jun-ichi Hakui, Hiroaki Fukazawa
    1992 Volume 65 Issue 5 Pages 1244-1251
    Published: 1992
    Released: July 14, 2006
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    Reactions of the title compounds with 2,3-dichloro-4,5-dicyano-p-benzoquinone were reinvestigated; it was found that the corresponding products were not the ring-contracted and rearranged thieno[2,3-b]indolizines, as described previously by us, but were ordinary dehydrogenated compounds, pyrido[2,1-c]thieno[3,2-e][1,4]thiazines. In contrast with pyrido[2,1-c]thieno[3,2-e][1,4]thiazine derivatives which have no substituent or only one methyl group on the pyridine ring, their 6,8-dimethyl compounds could be smoothly converted by keeping them at room temperature or heating their ethanolic solution to the corresponding desulfurized or rearranged 6,8-dimethylthieno[2,3-b]indolizine derivatives in moderately to good yields. The structures of these pyrido[2,1-c]thieno[3,2-e][1,4]thiazines and thieno[2,3-b]indolizines were assigned mainly based on elemental analyses, and spectral inspections; X-ray analyses for two compounds finally confirmed the former structure, pyrido[2,1-c]thieno[3,2-e][1,4]thiazine.
  • Masaru Tada, Tamaki Shimizu
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1252-1256
    Published: 1992
    Released: July 14, 2006
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    (1-Methylene-2-propenyl)cobaloxime (1), a diene having a transition metal substituent, was prepared conveniently from 2-chloromagnesio-1,3-butadiene and chlorocobaloxime. Cobaloxime 1 gives Diels–Alder adducts with olefinic dienophiles (maleic anhydride, N-phenylmaleimide, p-benzoquinone, dimethyl fumarate, methyl vinyl ketone, and methyl acrylate) and acetylenic dienophiles (methyl propiolate and dimethyl acetylenedicarboxylate). The reactivity of cobaloxime 1 is higher than that of its metalloid analogs, such as 2-silyl-, 2-seleno-, and 2-stannyl-1,3-butadiene, though the reaction pattern is essentially the same. This additional activation of the diene system by cobaloxime is accounted for by a back donation of the filled d-orbital of cobalt(III) to the π-system of the diene.
  • Masakazu Yamashita, Haruyoshi Tashika, Masaya Uchida
    1992 Volume 65 Issue 5 Pages 1257-1261
    Published: 1992
    Released: July 14, 2006
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    Alkyl vinyl ketones and acrylic esters were hydroacylated with organotetracarbonylferrates to the corresponding 1,4-diketones and 4-oxo carboxylic acid derivatives in good yield in dipolar aprotic solvents such as N,N-dimethylacetamide. Addition of 18-crown-6 improved the yield. cis-Jasmone and γ-jasmolactone were synthesized by use of these reactions.
  • Akihiko Tomoda, Akira Kaneko, Hideki Tsuboi, Ryouka Matsushima
    1992 Volume 65 Issue 5 Pages 1262-1267
    Published: 1992
    Released: July 14, 2006
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    Aiming at practical uses of photochromic compounds as data-storage media, electron-donating (e.g. p-dimethylaminophenyl) and conjugate chain (e.g. p-dimethylaminostyryl) substituted heterocyclic fulgides, e.g. 2-[1-(2-substituted 5-methyl-4-oxazolyl)ethylidene]-3-isopropylidenesuccinic anhydride and 2-[1-(5-substituted 2-methyl-3-thienyl)ethylidene or methlyene]-3-isopropylidenesuccinic anhydride, were prepared. The effect on photochromic performance was also investigated; it was clarified that substituents had effects on the red-shift and a significant increase in the color intensity of a colored form. However, the rate of the discoloration reaction was also affected, depressed, by the substituent.
  • Chikao Hashimoto
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1268-1274
    Published: 1992
    Released: July 14, 2006
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    Sperm whale myoglobin-(91–96)- (6a), -(85–90)- (7a), -(77–84)- (8), -(85–96)- (9a), and -(77–96)- (10) peptides were prepared. The products, derived from protected myoglobin-(91–96)-, -(85–90)-, and -(85–96)-peptides, partly changed into peptides containing a pyroglutamic acid residue in the course of purification by various forms of column chromatography. The circular dichroism (CD) spectra of free peptides 6a, 7a, 8, 9a, and 10 in 0.10 M phosphate buffers at pH 4.00, 6.50, and 8.50 were not typical of the helical structure. However, the CD spectra of peptides 7a, 9a, and 10 in 60% 2,2,2-trifluoroethanol–0.10 M phosphate buffers at the same pHs showed profiles characteristic of a helical structure.
  • Masami Sawada, Motohiro Shizuma, Yoshio Takai, Hitoshi Yamada, Takanor ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1275-1279
    Published: 1992
    Released: July 14, 2006
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    The 1 : 1 adduct ion formation between a series of per-O-acetylated aldopyranoses (family 1) or N-butylated glycosylamines (family 2) and an organic/metallic cation (n-C8H17NH3+/K+ or Li+) has been examined using quantitative FAB mass Spectrometry. The per-O-acetyl modifications dramatically lead to negated selectivity of the carbohydrates toward the cation which has been clearly observed in per-O-methyl modifications. On the other hand, the mono-N-butyl modifications provide a similar selectivity pattern to mono-O-methyl ones. These results are understood on the basis of electronic and structural considerations.
  • Tetsuo Kusumoto, Kenji Ando, Tamejiro Hiyama
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1280-1290
    Published: 1992
    Released: July 14, 2006
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    Hydrosilylation of 1,4-bis(trimethylsilyl)butadiyne using various hydridosilanes and Pt(IV), Pt(0), Rh(I) or Pd catalyst gave, depending on catalyst and hydridosilane, 1,1,3,4-tetrasilyl-substituted 1,3-butadienes or 1,1,3,4-tetrasilyl-substitued 1,2-butadienes. Formation of the 1,2-butadienes was proved to be attributable to second hydrosilylation of primary products 1,2,4-trisilyl-1-buten-3-ynes. For the second hydrosilylation a mechanism was proposed that involves silylmetalation induced through a metalacyclopropene intermediate.
  • Makoto Sakakibara, Takeshi Toru, Takahiro Imai, Yoshihiko Watanabe, Yo ...
    1992 Volume 65 Issue 5 Pages 1291-1294
    Published: 1992
    Released: July 14, 2006
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    Selenation of 2-bromonaphthoquinone with an areneselenolate ion generated from bis(2-methoxy-carbonylphenyl) diselenide, chlorodiphenylphosphine, and LiOH afforded 2-[(2-methoxycarbonylphenyl)seleno]-1,4-naphthoquinone from which 12H-benzo[b]naphtho[2,3-e]selenin-6,11,12-trione was synthesized. 1,4-Dimethoxy-2,3-dimethyl-10H-dibenzo[b,e]selenin-10-one was prepared starting from 6-bromo-2,3-dimethylbenzoquione through the selenation and cyclization steps.
  • Kenji Tabata, Shigemi Kohiki
    1992 Volume 65 Issue 5 Pages 1295-1298
    Published: 1992
    Released: July 14, 2006
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    The interaction of CH4 with LaCoO3 has been studied at room temperature with the use of an X-ray photoelectron spectroscopy (XPS) analyzer. CH4 dissociated on the surface of LaCoO3, and new carbonaceous products were detected at 104 langmuir exposure on the spectra for C1s. Since the intensities of the adsorbed oxygen on the spectra for O1s gradually decreased in proportion to the increase in the amount of CH4 exposure, methane reacted with adsorbed oxygen of LaCoO3 at room temperature in an XPS analyzer.
  • Hiroshi Sato, Yoshiharu Yagi
    1992 Volume 65 Issue 5 Pages 1299-1306
    Published: 1992
    Released: July 14, 2006
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    Some organic halogenides were found to induce a catalytic activity in a nickel naphthenate (Ni(naph)2)/AlEt3 system for the stereospecific polymerization of butadiene to a high cis-1,4 microstructure. These new activators were fluorinated carbonyl (or carboxyl) compounds, halogenated phenols or halogenated hydroquinones. These compounds were assumed to induce polymerization activity through the formation of Lewis acidic components with AlEt3. For this catalyst, H2O acted as an efficient molecular weight promoter.
    (Trifluoromethyl)benzene was found to promote the activity of a catalytic system: Ni(naph)2/AlEt3/organic halides. AlEt2F was found to be formed between AlEt3 and (trifluoromethyl)benzene. Finally, a simple system was found to be an efficient catalyst, Ni(naph)2/AlEt2F/H2O, for which chlorinated phenols acted as an effective molecular weight regulator.
  • Hiroshi Sato, Seimei Yasui
    1992 Volume 65 Issue 5 Pages 1307-1312
    Published: 1992
    Released: July 14, 2006
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    Liquid polybutadiene and liquid polyisoprene, which are usefull precursor for coatings, plastisizers or lubricants, were effectively synthesized by polymerizing butadiene and isoprene, respectively, in the presense of a nickel-containing Ziegler-type catalyst utilizing a lower α-olefin or molecular hydrogen as a molecular weight regulator. The catalyst consists of four components; nickel naphthenate (Ni(naph)2)/AlEt3/(trichloromethyl)benzene(BTC)/triphenyl phosphite (TPP) or triphenylphosphine (TPN). The microstructure of these liquid polymers is mainly 1,4-(cis/trans), which is advantageous for their reactivity and the rheological properties. The hydrogenated low molecular weight liquid polyisoprene exhibited very similar properties to those of squalane, which is a hydrogenated product of natural squalene.
  • Koji Kondo, Nobumasa Ishida, Junji Ishikawa, Masahiro Irie
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1313-1316
    Published: 1992
    Released: July 14, 2006
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    The electroless copper plating rate dependence on the various ligands, such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), N,N,N′,N′-tetrakis(2-hydroxypropyl)-ethylenediamine (HPA), N,N,N′,N′-tetrakis(2-hydroxyethyl)-ethylenediamine (HEA), triethanolamine (TEA), and triisopropanolamine (TIPA), were examined. TEA solution plating rate was the fastest of all ligands, the maximum rate being over 20 times faster than the current rate observed in the EDTA system. In order to reveal the rate dependence on the ligand, the adsorption equilibrium constants for Cu(II)-ligand complex onto the adsorbed ligand and the maximum deposition rates were determined based on the plating model previously proposed. The dependence was explained using the ligand adsorption equilibrium constant; (K1) onto the reactive surface; (K2) onto the adsorbed complexes and (K3) the complex adsorption equilibrium constant.
  • Kenji Ohmori, Masabumi Yoshimura, Mitsuo Koshi, Hiroyuki Matsui
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1317-1322
    Published: 1992
    Released: July 14, 2006
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    ArF laser photolysis in the mixtures of CH4 and O2 highly diluted in Ar has been conducted behind reflected shock waves, where O and H atoms have been monitored using the ARAS technique. The rate constant for the reaction CH4 + O → CH3 + OH (1) has been directly determined to be 10−8.95 ± 0.27 exp [−(15.4 ± 2.0)kcal mol−1/RT] cm3 molecule−1 s−1 over the temperature range of 1365–1840 K. Also the consecutive reactions; CH3 + O2 → CH3O + O (3a) and CH3 + O2 → CH2O + OH (3b) have been examined more directly than in previous thermally initiated experiments, and the combinations of k3a and k3b have been evaluated at the temperature range from 1622 to 1840 K.
  • Noriaki Funasaki, Hiromi Yodo, Sakae Hada, Saburo Neya
    1992 Volume 65 Issue 5 Pages 1323-1330
    Published: 1992
    Released: July 14, 2006
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    General and rigorous theory for equilibrium concentrations of uncomplexed species and 1 : 1, 1 : 2, 2 : 1, and 2 : 2 complexes of cyclodextrin (D) and surfactant has been developed and applied to evaluate the binding constants of these complexations from surface tension data of aqueous solutions of dodecyl maltoside (DM) with α-, β-, and γ-D, reported by Saeger and Muller-Fahrnow. The orders of the binding constants for 1 : 1 and 2 : 1 complexations of D and DM are α-D > β-D > γ-D. Those for 1 : 2 and 2 : 2 complexations are γ-D > β-D > α-D. These orders are explained on the basis of the goodness of fit of the dodecyl chain into the cyclodextrin cavity. Furthermore, the theory for the effects of D on the molar conductivity and the critical micelle concentration (cmc) of an ionic surfactant is modified by accounting for the change of these values with the surfactant concentration and applied to evaluate the binding constants for 1 : 1, 1 : 2, and 2 : 1 complexations of sodium dodecyl sulfate (SDS) and β-D from conductance and cmc data reported by Palepu and Reinsborough. Although there are several uncertainties in experimental data and their interpretations for the β-D-SDS system, the 1 : 1 complexation is predominant and its binding constant appears to be 5000 dm3 mol−1. Based on the present analysis, it is suggested that since a surfactant is a long and fine molecule, relative to aromatic compounds, its ternary and quaternary complexes with D’s as well as its binary complex should be taken into consideration.
  • Yasuaki Okamoto, Kozo Nagata, Toshinobu Imanaka, Kazuhiro Inamura, Tos ...
    1992 Volume 65 Issue 5 Pages 1331-1341
    Published: 1992
    Released: July 14, 2006
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    It was found that the catalytic activities and selectivities of cobalt sulfide catalysts are significantly affected by the calcination temperature of precursor cobalt oxide for the hydrogenation of butadiene and the isomerization of 1-butene. When cobalt sulfide was prepared from cobalt oxide calcined at 1473–1573 K, the specific activities per surface area of the sulfide were enhanced by 30–40 times those of cobalt sulfide prepared from cobalt oxide calcined at a conventional temperature, 573–973 K. The reaction selectivities were also strongly modified by the calcination temperature of precursor oxide. It is suggested that two different types of active sites are formed on cobalt sulfide, depending on the calcination temperature of the precursor. On the basis of XPS, XRD, SEM, and NO adsorption techniques, it is concluded that the particle size of the precursor cobalt oxide and sulfiding conditions determine the surface sulfur content and hence the catalytic properties of the sulfide catalysts. The sulfidation mechanism of cobalt oxide and active site models are proposed.
  • Kazunori Maruyama, Yasunori Kuramoto, Yoshié Tanizaki, Michio K ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1342-1348
    Published: 1992
    Released: July 14, 2006
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    The rate constants of two parallel reactions, photodegradation and photoisomerization of polyenes, CH=CHn with n = 2–5, produced in heat-treated PVA film are estimated by an analysis of the spectral changes on monochromatic irradiation (200–250 nm). The rate constants for isomerization is found to be ten times as large as that of degradation.
  • Yoshizumi Kajii, Tadashi Suzuki, Yoshiki Takatori, Kazuhiko Shibuya, K ...
    1992 Volume 65 Issue 5 Pages 1349-1355
    Published: 1992
    Released: July 14, 2006
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    Two-step photo-absorption processes of benzophenone and photodissociation of the highly-excited triplet state have been investigated in solution by the time-resolved thermal lensing technique. Two-step absorption processes at 308 nm are found to be composed of the first S1 ← S0 absorption followed by a rapid intersystem crossing to T1 and the second Tn ← T1 absorption. The quantitative analysis of time-resolved thermal lensing signals leads to an unexpected result that only 51 ± 6 % of the photon energy absorbed by the molecule in T1 has been detected as the heat released back to the system. This observation could be explained by a model that a fast photodissociation of benzophenone takes place from Tn. The chemical evidence and energy consideration support the dissociation into two phenyl radicals and a carbon monoxide molecule.
  • Masayasu Akiyama, Akira Katoh, Masakazu Iijima, Takeshi Takagi, Keiko ...
    1992 Volume 65 Issue 5 Pages 1356-1361
    Published: 1992
    Released: July 14, 2006
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    A nonapeptide with an Ala–(HO)Gly–Ala sequence has been synthesized via condensation of appropriately protected tripeptide units. 1H NMR and CD spectral data indicate that the nonapeptide has a disordered structure in DMSO and water. The peptide forms a 1 : 3 complex of iron(III) with hydroxamate groups at neutral pH when mixed with an aqueous iron(III) solution. The complex shows λmax at 410 nm with an ε of 2160 at pH 7. Alanine residues influence the hydroxamate groups to produce a chiral complex, the CD spectrum of which reveals bands at 355 nm (Δε+0.8) and 435 nm (Δε−1.8), showing a preference for the Δ-configuration around the iron.
  • Toshikazu Ibata, Hirofumi Nakano, Hatsue Tamura
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1362-1370
    Published: 1992
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    The 1,3-dipolar cycloaddition of 1-methoxy-2-benzopyrylium-4-olate (2) generated by Cu(acac)2-catalyzed decomposition of methyl 2-diazoacetylbenzoate with various aryl isothiocyanates and methyl isothiocyanate gave 2 : 1-, 3 : 1-, 4 : 1-, and 5 : 1-adducts without affording 1 : 1-adduct. The first cycloaddition of 2 occurs on the C=N double bond of isothiocyanate. The cycloadditions of the following steps, such as second, third, fourth, and fifth cycloadditions, proceed on C=O group of the cycloadducts of each previous steps. The molecular structure of the 2 : 1-adduct of 2 with phenyl isothiocyanate was determined by means of X-ray crystallography. Colorless crystals of the adduct are monoclinic with the space group P21/a, and with the unit-cell dimensions of a = 12.619 (4), b = 16.432 (4), c = 11.238 (2) Å, β = 97.39 (1)°, and Z = 4. The structure was calculated by direct methods (MULTAN 80) and refined by block-diagonal least-squares methods. All hydrogen atoms were revealed by a difference-Fourier synthesis, and further least-squares refinements gave the final R value of 0.046.
  • Chang-Yi Qian, Takashi Yamada, Hiroshi Nishino, Kazu Kurosawa
    1992 Volume 65 Issue 5 Pages 1371-1378
    Published: 1992
    Released: July 14, 2006
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    The reaction of 1,1-diphenylethene, 1,1-bis(4-chlorophenyl)ethene, 1,1-bis(4-methylphenyl)ethene, 1,1-bis(4-methoxyphenyl)ethene, and 1,1-bis(4-fluorophenyl)ethene with 2-methyl-1,3-cyclohexanedione, 2-methyl-1,3-cyclopentanedione, 2-acetylcyclohexanone, ethyl 2-acetyl-3-oxobutanoate, 3-methyl-2,4-pentanedione, 1,3-cyclohexanedione, and 2,4-pentanedione in the presence of Mn(OAc)2 and molecular oxygen yielded the corresponding cyclic peroxides in moderate-to-good yields. Similar reaction of 1,1-disubstituted alkenes with 1,3-cyclopentanedione in the presence of Mn(OAc)3 and molecular oxygen gave 2,2,9,9-tetraphenyloctahydro-3,4,7,8-tetraoxabenz[c]indene-4a,6a-diols. Acid-catalyzed decomposition of 4-acetyl-6,6-diaryl-3-methyl-1,2-dioxan-3-ols yielded 3-acetyl-5-aryl-2-methylfurans in moderate yields. Treatment of the 4-acetyl-6,6-diaryl-3-methyl-1,2-dioxan-3-ols with alkali gave 6,6-diaryl-3-methyl-1,2-dioxan-3-ols which gave 1-aryl-1,4-pentanediones upon treatment with hydrochloric acid in acetic acid. The synthetic utility and mechanisms of the reactions are discussed.
  • Noriyoshi Iwata, Tetsuro Morioka, Toshifumi Kobayashi, Takahiro Asada, ...
    1992 Volume 65 Issue 5 Pages 1379-1388
    Published: 1992
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    (E)-2-Iodo-1-tosyl-1-alkenes readily available by iodosulfonization of 1-alkynes were found to be useful synthons for the regio- and/or stereoselective preparation of 1-tosyl-1-alkynes, 1-tosyl-2-alkynes, (Z)-vinyl and (Z)-allyl sulfones, β-tosyl enamines, α-tosyl ketones, α-tosyl aldehyde acetal, and β-disubstituted vinyl sulfones.
  • Masanori Wada, Hiroyuki Wakamori, Akira Hiraiwa, Tatsuo Erabi
    1992 Volume 65 Issue 5 Pages 1389-1391
    Published: 1992
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    With a hope to explore a facile method for preparation of 1-halo-2,6-dimethoxybenzenes, bis(2,6-dimethoxyphenyl)dimethyltin was prepared from 1,3-dimethoxybenzene, butyllithium, and dimethyltin dichloride or dimethyltin sulfide. The compound reacted with N-chlorosuccinimide and with N-bromosuccinimide in methanol to afford 1-chloro-2,6-dimethoxybenzene and 1-bromo-2,6-dimethoxybenezene, respectively. The dimethyltin by-product was obtained either as dimethyltin oxide or as dimethyltin sulfide. A reaction with iodine was performed in the presence of potassium sulfide to afford 1-iodo-2,6-dimethoxybenzene and dimethyltin sulfide. Preparation and reactions of analogous organosilanes also are described.
  • Koichi Narasaka, Takanori Shibata, Yujiro Hayashi
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1392-1396
    Published: 1992
    Released: July 14, 2006
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    Several types of addition reactions proceed between Schiff’s bases and olefinic nucleophiles containing an alkylthio substituent. Ketene dithioacetal or 2-(methylthio)allylsilane reacts with Schiff’s bases in the presence of trifluoromethanesulfonic acid to afford β-amino acid equivalents or homoallylic amines, respectively. On the other hand, ene reaction proceeds between 1-alkyl-1,2-propadienyl sulfides and Schiff’s bases by treatment with AlCl3, giving 1,3-dienes.
  • Akiko Okumura, Midori Fushimi, Hiroko Hanaki, Akiko Yamada, Youko Gofu ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1397-1405
    Published: 1992
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    The rates (RS) of the oxygen exchange reaction of alkylarsonates (methyl-, butyl-, hexyl-, and benzyl-) and dialkylarsinates (dimethyl- and dibutyl-) with solvent water were measured in the pH range greater than 6, and at temperatures between 30 and 0 °C. For arsonates, the rate (R) is expressed by the following rate law: R = k1[A2−] + k2[HA] + k3[H2A] + k4[HA]2 + k5[HA][H2A] + k6[H2A]2, where A2−, HA, and H2A designate R′AsO32−, R′AsO3H, and R′AsO3H2 (R′ = alkyl), respectively. For arsinates, R = k1[R′2AsO2] + k2[R′AsO2H] (pH > 9). The exchange rates of arsonates at 0 and 30 °C were analyzed in terms of the rate law to obtain the values of the rate constants (k1k6). The activation parameters were obtained for the k1 paths of both arsonates and arsinates, which are the reaction between R′AsO32− or R′2AsO2 and water. It is noticeable that the values of the activation entropies of the arsonates were found to be negative, while those of the arsinate were found to be positive. It was suggested that the oxygen exchange of arsonate ions proceeds via an SN2 mechanism, while that of arsinates preceeds via SN1.
  • Katsuhiko Fujio, Shoichi Ikeda
    1992 Volume 65 Issue 5 Pages 1406-1410
    Published: 1992
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    Static light scattering has been measured on aqueous NaCl solutions of 1-dodecylpyridinium chloride over the NaCl concentrations from 0 to 4.00 M at 25 °C, and the micelle molecular weight has been estimated by means of the Debye equation. In aqueous solution the molecular weight is as small as 5280, corresponding to the aggregation number, 18.6. With increasing NaCl concentration up to 0.05 M the molecular weight increases sharply, reaching 12350. The small micelles would not be so compact as the common spherical micelles but would be porous except for their core. With increasing NaCl concentration beyond 0.05 M the micelle molecular weight increases only gradually, similar to growth of the common spherical micelles, and reaches 20410 in 4.00 M NaCl.
  • Masaaki Abe, Yoichi Sasaki, Akira Nagasawa, Tasuku Ito
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1411-1414
    Published: 1992
    Released: July 14, 2006
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    Substitution reactions of py-d5 for the terminal pyridines of the three triruthenium complexes, [Ru33-O)(μ-CH3COO)6(py)3]+ (1) (Ru3(III, III, III)), Ru33-O)(μ-CH3COO)6(py)3 (2) (Ru3(II, III, III)), and Ru33-O)(μ-CH3COO)6(CO)(py)2 (3) (Ru3(II, III, III)), have been studied in CD3CN by following the change in 1H NMR spectra. The rates are practically independent of [py-d5] (0.05–1.0 mol dm−3). The first-order rate constants are 3 × 10−5 s−1 at 55 °C (ΔH = 123 ± 6 kJ mol−1, ΔS = +41 ± 19 J K−1 mol−1), 5.9 × 10−4 s−1 at 50 °C (ΔH = 122 ± 14 kJ mol−1, ΔS = +69 ± 44 J K−1 mol−1), and 3 × 10−5 s−1 at 55 °C (ΔH = 126 ± 9 kJ mol−1, ΔS = +52 ± 27 J K−1 mol−1) for 1, 2, and 3, respectively. Rate constants appear to depend on the apparent oxidation state of the metal center. While the three Ru ions in 2 are equivalent and each ion has average oxidation number +2(2/3), Ru ions with coordinated py in 3 are in +3 oxidation state as the +2 oxidation state is localized at carbonyl-Ru ion. A dissociative mechanism is proposed for these reactions on the basis of the absence of [py-d5]-dependence, the activation parameters, and the comparison of the rate constants with those of the substitution of methanol-d4 for the terminal water ligands in [Ru33-O)(μ-CH3COO)6(H2O)3]+.
  • Satoru Onaka, Takeshi Moriya, Shigeru Takagi, Atushi Mizuno, Hiroyuki ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1415-1427
    Published: 1992
    Released: July 14, 2006
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    Four kinds of methal carbonyl complexes with 1,1′-bis(diphenylphosphino)ferrocene (dppfe) are synthesized and their molecular structures are determined by single-crystal X-ray analyses. Crystal data for (η5-CH3C5H4)Mn(CO)2dppfe (1), (η5-CH3C5H4)Mn(CO)dppfe (2), [ClMn(CO)4]2(μ-dppfe) (3), and CH3CCo3(CO)7dppfe (4) are as follows: 1, Pbca, a = 20.551(3), b = 28.951(5), c = 11.786(1) Å, V = 7012(2) Å3, Z = 8; 2, P21/n, a = 18.682(5), b = 20.495(4), c = 9.750(2) Å, β = 91.24(2)°, V = 3732(1) Å3, Z = 4; 3, A2/a(C2/c), a = 18.978(5), b = 15.293(4), c = 16.513(5) Å, β = 112.62(2)°, V = 4423.9(2) Å3, Z = 4; 4, , a = 13.031(2), b = 15.338(2), c = 11.583(2) Å, α = 99.13(2)°, β = 98.35(2)°, γ = 99.64(2)°, V = 2218.1(7) Å3, Z = 2; Mo Kα radiation; R = 0.075, 0.084, 0.074, and 0.056 for 2639, 4219, 2575, and 6098 reflections, respectively. Dppfe functions as a monodentate ligand in 1 with the rotational angle 128.0° for two cyclopentadienyl rings, as a bidentate chelating ligand in 2 with the rotational angles 3.1°, as a bidentate bridging ligand (no metal–metal bond) in 3 with the rotational angle 180°, and as a bridging ligand (over metal-metal bond) in 4 with the rotational angle 69.6°, respectively; Mn–P = 2.242(4) Å (1), Mn–P = 2.215(2) and 2.216(3) Å (2), Mn–P = 2.364(4) Å (3), and Co–P = 2.297(2) and 2.314(2) Å (4). The two cyclopentadienyl rings of dppfe are slightly tilted (2.3–5.7° for tilt angles in 1, 2, and 4) and are parallel in 3. The coordinated P atoms are significantly displaced from the cyclopentadienyl ring planes. From the comparison of these geometrical parameters, it is concluded that the rotation of the two cyclopentadienyl rings is a predominant factor to determine various coordination modes of dppfe rather than the tilt of the two rings and/or the deviation of the P atoms from the ring plane. The 57Fe Mössbauer spectra of this series of compounds show doublets with parameters (IS = 0.50–0.52 mm s−1 relative to Fe, QS = 2.22–2.35 mm s−1). Although isomer shifts are essentially constant, the quadrupole splittings have a tendency to increase with the increase of the rotational angle of the two cyclopentadienyl rings. 1H and 31P NMR spectra are measured for all of these compounds.
  • Reiko Saito, Masafumi Goto, Junzo Hirose, Yoshinori Kidani
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1428-1437
    Published: 1992
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    Square-planar complexes with the formula [PtCl2(R-Hb-Mepn)], where R-Hb-Mepn is (R)-2-[(2-methyl-2-aminopropyl)amino]-1-butanol CH3CH2CH(CH2OH)NHCH2C(CH3)2NH2, were synthesized and separated into two diastereoisomers. On the basis of CD spectroscopic and X-ray crystallographic analyses, (+)300- and (−)300-isomers were determined to have the R-nitrogen center with λ chelate ring and the S-nitrogen center with δ chelate ring, respectively. R(N)-[PtCl2(R-Hb-Mepn)] crystallizes in the monoclinic space group P21 with a = 8.809 (1), b = 8.9960 (4), c = 8.536 (1) Å, β = 108.787 (5)°, Z = 2, R = 0.042, and RW = 0.062. S(N)-[PtCl2(R-Hb-Mepn)] crystallizes in the orthorhombic space group P212121 with a = 9.287 (1), b = 14.831 (1), c = 9.141 (1) Å, Z = 4, R = 0.029, and RW = 0.034. 1H NMR spectra indicate that R-Hb-Mepn chelate rings take fixed conformation in acidic D2O solution. At high temeprature (90–95 °C), the conversion of the R(N)-isomer to the S(N)-isomer occurred easily. The R(N)-[PtCl2(R-Hb-Mepn)] and S(N)-[PtCl2(R-Hb-Mepn)], respectively, show the opposite Cotton effect to that of the reported complexes R(N)-[PtCl2(S-Me-pn)] and S(N)-[PtCl2(S-Me-pn)] (S-Me-pn = (S)-1-methylamino-2-aminopropane). The kinetic data of a reversible inversion reaction at the nitrogen were consistent with the usual base catalyzed mechanism.
  • Masaaki Tabata, Kazuhiko Ozutsumi
    1992 Volume 65 Issue 5 Pages 1438-1444
    Published: 1992
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    Formation of the 2 : 1 mercury(II) porphyrin complex, Hg2(tpps)2− (H2tpps4−: tetrakis(4-sulfonatophenyl)porphyrin), in aqueous solution has been investigated. Equilibrium studies revealed that main chemical species is Hg2(tpps)2− even in a solution of a 1 : 1 molar ratio of Ctpps/CHg and the Hg2(tpps)2− complex is very stable thermodynamically. EXAFS (extended X-ray absorption fine structure) analysis of the Hg2(tpps)2− complex in aqueous solution showed that the Hg–N bond length within the complex is 215(2) pm and the bond length is much shorter than the Hg–O bond length (240 pm) within the hydrated mercury(II) ion. Thus the very strong Hg–N bond is formed upon the complexation of Hg2(tpps)2− and the strong bond formation supports the high stability of the Hg2(tpps)2− complex. Deformation of Hg2(tpps)2− is also discussed in connection with catalytic effect of mercury(II) on metalloporphyrin formation.
  • Tamás Radnai, Shin-ichi Ishiguro, Hitoshi Ohtaki
    1992 Volume 65 Issue 5 Pages 1445-1452
    Published: 1992
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    The structure of the tri- and tetrathiocyanato-N-manganate(II) complexes in N,N-dimethylformamide (DMF) solution was determined by the solution X-ray diffraction method at 25 °C. The most probable structure of the tri-complex is octahedral with additional three DMF molecules in the first coordination sphere, while the tetra-complex is tetrahedral. The Mn–O and Mn–N bond lengths were determined to be 220 pm in both complexes. The structure of the octahedrally solvated lithium ion [Li(dmf)6]+ with the Li–O bond length of 195 ppm was also determined in an LiSCN solution of DMF.
  • Toshihiro Yamase, Tomoji Ozeki, Shigeyuki Motomura
    1992 Volume 65 Issue 5 Pages 1453-1459
    Published: 1992
    Released: July 14, 2006
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    Peroxo complexes prepared by the reaction of titanoundecatungstophosphate (PTiW11O405−) and dititanodecatungstophosphate (PTi2W10O407−) with hydrogen peroxide are characterized by means of the 183W NMR spectroscopy and the single crystal X-ray diffractometry. Electronic spectra and permanganate titration analyses indicated that one peroxo ligand attaches to the PTiW11O405− anion and two peroxo ligands attach to the PTi2W10O407− anion. 183W NMR spectra showed that the Cs symmetry of the PTiW11O405− anion and the C2 symmetry of the PTi2W10O407− anion are retained in the respective peroxo derivatives. Single crystal X-ray structures of the diisopropyl ammonium salt of PTiW11O405−, the diisopropyl ammonium salt of PTiW11O39(O2)5− and the isopropyl ammonium salt of PTi2W10O38(O2)27− indicated that the peroxo anions retain the α-Keggin structures of their parent anions. It was inferred that the peroxo ligands are substituted for the terminal oxygen atom at the TiO6 octahedra with the side-on format.
  • Takehiko Mori, Hiroo Inokuchi
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1460-1462
    Published: 1992
    Released: July 14, 2006
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    The title charge-transfer complex, where TTF is tetrathiafulvalene, and DMeT-DCNQI is 2,5-bis(methylthio)-p-benzoquinone bis(N-cyanoimine), crystallizes in triclinic space group , a = 15.447 (3), b = 15.774 (3), c = 3.834 (2) Å, α = 96.96 (3), β = 97.14 (3), γ = 82.24 (2)°, V = 913 (5) Å3 and Z = 2. The donor and acceptor molecules form segregated colums. This complex shows high electrical conductivity, 400 S cm−1 at room temperature, and undergoes a metal-semiconductor transition at around 130 K.
  • Osamu Kikuchi, Katsunori Segawa, Ohgi Takahashi, Tatsuo Arai, Katsumi ...
    1992 Volume 65 Issue 5 Pages 1463-1465
    Published: 1992
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    The potential energy curves of triplet states of styrene, 2-vinylnaphthalene and 2-vinylanthracene were calculated by the restricted open-shell SCF MNDO methods as a function of the twist angle of the external double bond. It was shown that the shape of the lowest triplet potential energy curve is determined by the relative energies of two triplet states, the “ring-excitation” and “olefin-excitation” states.
  • Masahiro Mikuriya, Yo Yamato, Tadashi Tokii
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1466-1468
    Published: 1992
    Released: July 14, 2006
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    Reaction of 1,3-bis(salicylideneamino)-2-propanol (H3L) with manganese(II) acetate tetrahydrate in the presence of ethylenediamine and sodium thiocyanate give a salen complex [Mn(salen)(NCS)] (H2salen = N,N′-disalicylideneethylenediamine), while that in the presence of water and triethylamine gives a binulear manganese(III) complex [Mn2(L)2(H2O)]·3CH3OH. Both complexes have been characterized by X-ray crystal structure analyses, electronic spectra, and magnetic susceptibilities.
  • Taizo Hatta, Shuntaro Mataka, Satoshi Tanimoto, Masashi Tashiro, Otohi ...
    Type: Article
    Subject area: AI
    1992 Volume 65 Issue 5 Pages 1469-1471
    Published: 1992
    Released: July 14, 2006
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    Monotosylhydrazone (2) of [2.2.2]cyclophane-1,2-dione (1) decomposed on silica gel, giving the ring-contracted [2.2.1]cyclophane-17-carboxylic acid (4). The electronic spectrum of 4 showed a red shift of the λmax and a broadening of the peak shape in comparison with that of di-p-tolylacetic acid, due to a through-space π–π interaction. Thermolysis of bis(tosylhydrazone) (3) afforded [2.2.2] cyclophan-1-en-1-yl p-toluenesulfonate (6). An intermediate formation of the corresponding[2.2.2]cyclophan-1-yne is suggested.
  • Kensuke Shima, Akira Sazaki, Kenichi Nakabayashi, Masahide Yasuda
    1992 Volume 65 Issue 5 Pages 1472-1474
    Published: 1992
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    A 9,10-dicyanoanthracene (DCA)-photosensitized reaction of 3-cyano- or 3-ethoxy-2,2-diarylthietane in acetonitrile gave selectively 2-cyano- or 2-ethoxy-1,1-diarylethene. The ring-splitting reaction proceeds via a one-electron oxidation of the sulfur atom of thietane ring by a photochemical electron transfer to the excited singlet state of DCA.
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