Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
67 巻 , 1 号
選択された号の論文の59件中1~50を表示しています
  • Jarugu Narasimha Moorthy, Kailasam Venkatesan
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 1-6
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    4-Styrylcoumarin crystallizes from chloroform and hexane mixture in two morphologically different modifications. The monoclinic form (needles, P21/c) undergoes stereospecific photodimerization producing anti head-to-tail dimer across pyrone double bond, whereas the triclinic modification (prisms, ) dimerizes yielding photodimer of the same configuration, but across styrenic double bond. Single crystal X-ray analyses of the dimorphs reveal the packing differences permitting rationalization of the regio- and stereochemistry of the photoproducts. The significantly low dimer yield from the prismatic crystals is rationalized.
  • Olasoji Abayomi Amire
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 7-12
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The dynamics of the process of formation of cholesterol films on a solid substrate prepared by the spontaneous self-assembly technique has been investigated. An expression for the coverage in a multilayer system was derived. Application of the equation to cholesterol multilayer film formation kinetics shows that the approach to equilibrium of the self-assembly process obeys first-order rate law. An observed adsorption free energy change of −21.7 ± 0.1 kJ mol−1 was obtained for cholesterol on quartz slide and a mean lifetime of cholesterol on the slide surface during deposition of 78 ± 3 ks at 298.16 K. A mean lifetime for stearic acid adsorbed from hexadecane onto native aluminium oxide surface (data from elsewhere) was found to be 12.4 ± 0.3 ks. The results suggest dynamic processes which strongly depend on the formation constant of the amphiphile for coordination to the substrate.
  • Hiroshi Kubota, Yuriko Aoki, Akira Imamura
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 13-20
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The typical properties of a ferroelectric material are piezoelectricity and pyroelectricity. In this study we considered in detail the relationship between the pressure and the change in the dipole moment of a molecule in a ferroelectric crystal from the standpoint of piezoelectricity. We applied ab initio molecular orbital calculations involving the crystal effect to the orthorhombic thiourea ((NH2)2CS) crystal model as the ferroelectric crystal model. The molecular structure obtained by this calculation was in fairly good agreement with the result obtained by X-ray analysis. In order to investigate the substituent effects, we calculated a hypothetical orthorhombic N,N′-difluorothiourea ((NHF)2CS) crystal model in a similar manner.
  • Yukari Sato, Brian L. Frey, Robert M. Corn, Kohei Uosaki
    1994 年 67 巻 1 号 p. 21-25
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The effects of self-assembly time on the order and orientation of 11-ferrocenyl-1-undecanethiol (FcC11SH) molecular layers on gold were studied with polarization modulation Fourier transform infrared spectroscopy. A comparison between the intensity of the asymmetric methylene stretching mode of a 1-octadecanethiol monolayer and that of the FcC11SH molecular layer confirmed that the FcC11SH molecules formed a self-assembled monolayer on the gold surface. The conformational order of the monolayer increased with longer self-assembly time as evidenced by a decrease in the vibrational frequencies of the methylene stretching modes and a decrease in the full width at half maximum of these bands. The peak area of the asymmetric methylene stretch also decreased with longer self-assembly time, implying that the FcC11SH molecules stood more erect with respect to the gold surface as the monolayer self-assembled.
  • Norimasa Nakamura, Akihiro Yoshino, Kensuke Takahashi
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 26-30
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The 13C and 7Li NMR spectra of the title adducts were observed in THF. In a temperature range from 20 to −80 °C the adducts existed as contact ion pairs in THF. Below −70 °C, the adduct derived from pyridine or 4-phenylpyridine showed three 7Li signals related to three different associated species in solutions. On the other hand, the adduct derived from 2- or 3-phenylpyridine did not give such multiplet signals at −70 °C. The results are related to the interaction between nitrogen and lithium, and the extent of negative-charge migration into the substituent (phenyl ring) in the adduct.
  • Nagao Azuma, Takehiro Ozawa, Jun Yamauchi
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 31-38
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The crystal structures of two complexes of the 9-(9H-fluoren-9-ylidenephenylmethyl)-9H-fluoren-9-yl stable radical with benzene (BDPA–Bz) and acetone (BDPA–Ac) have been determined by X-ray diffraction at room temperature. They are an isostructure of a monoclinic system with a space group of P21/n. For BDPA–Bz, a = 9.502(2), b = 14.632(2), c = 19.452(2) Å, β = 93.64(1)°, V = 2699(1) Å3, Z = 4, Dx = 1.220 g cm−3. For BDPA-Ac, a = 9.657 (1), b = 14.675(2), c = 18.812(2) Å, β = 95.388(9)°, V = 2654.4(6) Å3, Z = 4, Dx = 1.190 g cm−3. The final R values are 0.043 and 0.062 for 5.47 and 3.93 ratio of the observed reflections versus the parameters for BDPA–Bz and BDPA–Ac, respectively. The BDPA molecules in both crystals have the same propeller shape with an approximated C2 symmetry. The molecular packing of these crystals does not show a one-dimensional stacking, in spite of the magnetic one-dimensionality elucidated by the magnetic susceptibilites. The exchange pathways are discussed based on the McConnell’s spin-density Hamiltonian.
  • Iwao Watanabe, Hajime Tanida, Keiichi Maya, Shigero Ikeda, Yu Yokoyama
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 39-45
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The solution-phase ionization potentials of I, Br, and SCN ions in 16 solvents including water have been measured by a photoelectron emission spectroscopic technique. The values obtained as the threshold energy Et for halides are found to be correlated well with the Mayer–Gutmann acceptor number and better with the Riddle–Fowkes modified acceptor number of the solvent indicating that the electronic states of the halides are predominantly stabilized through the Lewis acid–base interaction. The reorganization energies ΔGr of solvent after the photoionization of the halides are obtained from the Et values. The experimental ΔGr values are reproduced by using a simple model which incorporates the dipole–dipole repulsion and the bond formation energies in the first solvation layer. The solvation mechanism of SCN is somewhat different from those of the halides because its Et depends less on the acceptor number and its ΔGr values in alcohols are about half of those for the halides.
  • Masanobu Matsuguchi, Yoshihiko Sadaoka, Masafumi Shinmoto, Yoshiro Sak ...
    1994 年 67 巻 1 号 p. 46-51
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Water sorption behavior of four kinds of polymerized vinyl carboxylate, i. e., vinyl benzoate, vinyl methacrylate, vinyl crotonate, and vinyl cinnamate was investigated. The dielectric measurement and quartz crystal microbalance technique were adopted for this purpose. The polymers were hydrophobic and the water sorption ability was enhanced by cross-linking. The dielectric constant of sorbed water was small compared with that of liquid water and the value slightly increased with increasing the amount of sorbed water. The orientation polarization of sorbed water also slightly increased with increasing the amount of sorbed water. It was proved that the cross-linking structure affected the water sorption behavior of the polymer.
  • Takehiro Abe
    1994 年 67 巻 1 号 p. 52-55
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The reaction field energy of a non-ideal dipole directed along the radius vector in a spherical cavity has been formulated and compared with that of a point dipole located in the center of the cavity for two special cases. Thus, the validity of approximation of the point dipole used widely is investigated.
  • Yasuyuki Takeda, Chihiro Takagi
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 56-60
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    In order to determine the ion-pair formation constant of a crown ether–metal salt complex (1 : 1 : 1) in water, an equation is derived from the regular solution theory. Then, the theoretical predictions are verified experimentally by solvent extraction with 15-crown-5 (15C5), sodium picrate (NaA), and various organic solvents of low dielectric constant. The partition constants of 15C5 and the actual overall extraction constants of NaA with 15C5 were determined at 25 ± 0.2 °C. The partition constants of the Na(15C5)A complex are calculated from these data, the literature value for the complex-formation constant of Na(15C5)+ in water, and the ion-pair formation constant (KNa(15C5)A) in water determined in this study (log KNa(15C5)A = 4.09 ± 0.23 at 25 °C). The distribution behavior of 15C5 and Na(15C5)A is explained by the regular solution theory. The obtained molar volumes V/cm3 mol−1 and solubility parameters δ/cal1/2 cm−3/2 are as follows; V15C5 = 189 ± 34, VNa(15C5)A = 215 ± 46, δ15C5 = 12.0 ± 0.1, and δNa(15C5)A = 12.0 ± 0.1.
  • Adbel -Rahman El-Sayed, Hossnia Mohran, Farouk Rashwan
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 61-64
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The ac impedance of a planar indium electrode in both HCl and H2SO4 solution was measured at −20, 0.0, and 10 mV vs. the open circuit potentials. Various amounts of Bu4NBF4, Bu4NPF6, and Bu4NClO4 were gradually introduced to the electrolytic solution and the impedance of the electrode was remeasured. Subsequently, Rs, Rp, and Cdl, in the absence and presence of the additives, were computed and compared. It was found that Bu4NBF4 has an inhibitive action in both acids. On the other hand, acceleration of the electrochemical processes in the presence of Bu4NPF6 also in both acids, is observed. However, some retardation of the electrode reactions was obtained at the lowest concentration of the additive only in HCl. It is noteworthy that Bu4NClO4 has contradictory effects on the electrochemical processes, i. e. an inhibitive action in HCl solution, whereas in H2SO4 the electrode reactions are significantly enhanced.
  • Noriaki Funasaki, Sakae Hada, Saburo Neya
    1994 年 67 巻 1 号 p. 65-73
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The continuous flow model of chromatography for computer simulations is developed and applied for nonassociable, dimerizing, and micellar systems. This model is more realistic than the discontinuous flow model, since the former takes into account the infinitesimal flow of the mobile phase. The frontal and zonal chromatograms of sucrose, a nonassociable solute, are determined on a Sephadex G-10 column as a function of the total sucrose concentration. The derivative of the frontal chromatogram at the leading boundary completely overlaps with that at the trailing boundary and has the same shape with the zonal chromatogram. Therefore the number of plate can be calculated from the observed derivative chromatogram. For some dimerizing systems the dimerization constant can be estimated from the concentration dependence of the derivative at the trailing boundary, if an appropriate correction is applied. Some characteristic parameters obtained from the derivative chromatogram of the micellar system provide information on the aggregation pattern. The observed results outlined above can be semiquantitatively predicted by the continuous flow model and by the discontinuous flow model, if the void volume and the number of plate are regarded as adjustable parameters in the latter model.
  • Junko Takahashi, Takamasa Momose, Tadamasa Shida
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 74-85
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The thermal rate constants for SiH4 SiH3 + H and CH4 CH3 + H are calculated by the Canonical Variational Transition State Theory (CVTST). The minimum energy path potential and the deformation path potential along the reaction coordinate are calculated by the MCSCF-CI and UHF methods, respectively. The transitional bending mode which connects the bending vibrations of the parent molecules with the translational and rotational motions of the products of the dissociation is treated in terms of a two-dimensional quantum hindered rotor. The saddle points and the CVTST rate constants are determined by the maximum free energy criterion. Comparative discussions are made for the two systems. The calculated association rate constants for the SiH4 system are 8.4 × 1010 l mol−1 s−1 at 300 K and 12.5 × 1010 l mol−1 s−1 at 2000 K, while those for the CH4 system are 12.5 × 1010 l mol−1 s−1 and 18.6 × 1010 l mol−1 s−1 at the two temperatures. At all the temperatures studied the rate constant of the former system is smaller by 30—35% than the latter. The dissociation rate constants are evaluated to be 7.2 × 105 s−1 at 2000 K and 1.2 × 109 s−1 at 3000 K for the SiH4 system, while the constant for the CH4 system at 2000 K is about one order of magnitude smaller. This difference diminishes at higher temperatures. The results are also compared with experimental and other theoretical studies.
  • Hirochika Sakuragi, Ryoichi Nakagaki, Kazuhiko Naitoh, Takahisa Oguchi ...
    1994 年 67 巻 1 号 p. 86-92
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The efficiency of isomerization of trans-2-(3,3-dimethyl-1-butenyl)naphthalene (t-BN) in the presence of electron acceptors was reduced by an applied magnetic field in polar solvents such as acetonitrile. This effect together with laser flash photolysis studies indicates that the precursor of isomerization is the BN triplet arising from intersystem crossing of a singlet radical pair consisting of a t-BN cation and an acceptor anion. The external magnetic field effect as well as laser flash photolysis was employed to estimate the contribution of ion radical pairs to the isomerization of t-BN in the presence of p-dicyanobenzene in various solvents. The t-BN triplet was produced most efficiently almost through an exciplex in chloroform (ε = 4.8) among the employed solvents.
  • Kazuhiro Kanda, Kaoru Suzuki, Tamotsu Kondow, Haruhiko Ito, Kozo Kuchi ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 93-95
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The dynamics of dissociative excitation of BrCN or ICN producing CN(B2Σ+) radicals by Ar(3P2) or Kr(3P2) was investigated by using the flowing afterglow method. The observed vibrational distributions of CN(B) are consistent with the reported reaction mechanism for the CN(B) formation initiated by the transfer of the excitation energy of the metastable atom to the cyanide molecule.
  • Thatavarthi Ramalingeswar Rao, Poluri Anjana Kumar
    1994 年 67 巻 1 号 p. 96-100
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Lanthanoid complexes of 2-pyrazinecarboxamide (PYZA) of the composition, [LnCl3(pyza)3] (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Y), were synthesized and the structures of the isolated complexes studied by elemental analyses, molar conductance, magnetic susceptibility, electronic, FT-IR and multinuclear NMR spectral techniques. Presence of intra- and intermolecular hydrogen bonding in the non-complexed (free state) PYZA and intramolecular hydrogen bonding in the complexed ligand (Ln(III) complex) was indicated by the FT-IR spectra (solution and solid states). Non-coordination through the >C=O and –NH2 groups in the Ln(III) complexes was implied by the FT-IR (solution state) and 13C NMR spectra. The 139La NMR spectrum implied a predominantly ionic bond and low symmetry in the complexes. The hypersensitive band profile of the Nd(III) complex remained uneffected with respect to pH and temperature variations.
  • Takumi Konno, Ken-ichi Okamoto, Jinsai Hidaka
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 101-107
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The reaction of fac(S)-[Rh(aet)3] with ZnBr2 in water produced a T-cage-type S-bridged polynuclear complex with a “defective” [Zn3HO]5+ core, [{Rh(aet)3}4Zn3HO]Br5 (1Br5), which was subject to spontaneous resolution to give and isomers. 1 was also optically resolved into the two isomers with use of [Sb2(R,R-tartrate)2]2−. The crystal structure and absolute configuration for the spontaneously resolved isomer were determined by X-ray crystallography. [{Rh(C2H6NS)3}4Zn3HO]Br5·9H2O, crystallizes in the cubic space group P213 with a = 19.186 (1) Å, V = 7062.1 (4) Å3, Z = 4, and R = 0.0648. In 1 the four octahedral fac(S)-[Rh(aet)3] subunits are bound to a quasi-tetrahedral [Zn3HO]5+ core in a tetrahedral arrangement. The chiral configurations are regulated to Δ for all fac(S)-[Rh(aet)3] subunits and R for all asymmetric bridging sulfur atoms in -1, giving a quasi-T symmetrical structure. 1 is unstable in water and convertible to a T-cage-type octanuclear complex with a “complete” [Zn4O]6+ core, [{Rh(aet)3}4Zn4O]6+ (2), and to a linear-type S-bridged trinuclear complex, [Co{Rh(aet)3}2]3+, by adding ZnBr2 and [CoCl(NH3)5]Cl2, respectively. The electronic absorption and circular dichroism (CD) spectral behavior of 1 are discussed in comparison with those of 2.
  • Masaaki Kojima, Reiko Saito, Kiyohiko Nakajima, Yishan Ouyang, Junnosu ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 108-112
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Trans(N)-[Co(CO3)(dmgly)2] and trans(N)-[Co(ox)(dmgly)2] were prepared and characterized by absorption, circular dichroism, 1H NMR, and 13C NMR spectra, where Hdmgly and H2ox denote N,N-dimethylglycine and oxalic acid, respectively. The carbonato complex was yielded by the reaction of [CoCl(NH3)5]Cl2 and Hdmgly without addition of carbonate or hydrogencarbonate ions; decarboxylation of Hdmgly followed by substitution with CO32− was suggested. The molecular structure of spontaneously resolved (+)589-trans(N)-K[Co(CO3)(dmgly)2]·H2O was determined by the single crystal X-ray diffraction method. The crystal data and final R value are: orthorhombic, P212121, a = 15.483(1), b = 15.624(2), c = 6.092(1) Å, V = 1473.7(3) Å3, Z = 4, R = 0.022 for 2390 reflections. The crystal used had the Λ configuration. The mean Co–N bond length, 1.996 (2) Å is longer than the usual Co–N (primary amine) bond length by 0.03—0.08 Å due to the steric repulsion between the methyl groups and other ligands.
  • Yasuo Nakabayashi, Hiromu Imai
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 113-118
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The determination of Cu2+ by differential pulse voltammetry was carried out using a chemically modified electrode coated with a Nafion® film to the surface of a glassy carbon electrode (GC/NAF electrode). This method, which is based on the principle of ion-exchange equilibria between Nafion® and imidazole–copper(II) complex ions, is applicable to the determination of traces of Cu2+ by a measurement of the reduction current of the Cu(II) complex ions incorporated into the Nafion® film. The procedure is as follows: immerse the GC/NAF electrode in 10 cm3 of a sample solution containing traces (concentration, < 1.0 × 10−6 M) of Cu2+, 1.0 × 10−2 M of imidazole as the complexing agent, and 0.5 M of NaBr as the supporting electrolyte, and record the differential pulse voltammogram after stirring for 15 min at 25 °C. The reduction peak current obtained from this voltammogram was recoganize to be proportional to the Cu2+ concentration in the range of 1.0 × 10−7 to 1.0 × 10−6 M at pH 6.0 and 1.0 × 10−8 to 1.0 × 10−7 M at pH 7.0, respectively. The relative standard deviations for the peak currents obtained from four repeated determinations were 1.2 and 1.5% for 5.0 × 10−7 M of Cu2+ at pH 6.0 and 5.0 × 10−8 M of Cu2+ at pH 7.0, respectively. The diverse metal ions which coexist with Cu2+ at pH 6.0 did not interfere up to about a 100-fold excess of Mn2+, Co2+, Ni2+, and Cd2+, except for about a 10-fold excess of Fe3+, and about a 50-fold excess of Zn2+ for the Cu2+ concentration. This method was applied to the determination of Cu2+ in both waste- and river-water samples.
  • Tomozo Koh, Hideki Wakabayashi, Yasunobu Yonemura
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 119-124
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Aqueous thiosulfate was shaken in the presence of large amounts of sulfuric acid and formaldehyde with iodine in carbon tetrachloride; thereby, one mol of thiosulfate reacted with one mol of iodine. The organic phase was separated, the excess of iodine was extracted into an aqueous iodide solution as triiodide and the absorbance of the liberated triiodide was measured at 350 nm. The calibration plot obtained for thiosulfate did not form a linear graph and was not affected by a change in the volume of 10 to 27 cm3 of the sample solution. The proposed method could be applied to the determination of thiosulfate in the concentration ranges 5 × 10−7—3.4 × 10−5 mol dm−3 (0.056—3.81 ppm) for a 10 cm3 thiosulfate solution and 1.9 × 10−7—1.36 × 10−5 mol dm−3 (0.021—1.52 ppm) for a 25 cm3 thiosulfate solution. Good recoveries of thiosulfate from hot-spring and lake-water samples, to which various known amounts of thiosulfate had been added, was achieved and the relative standard deviation was 0.86% at the 5.42 × 10−6 mol dm−3 (0.608 ppm) thiosulfate level when applied to a hot-spring sample.
  • Yonezo Maeda, Yuichi Tanigawa, Naohide Matsumoto, Hiroki Oshio, Masata ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 125-130
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The Mössbauer spectra, magnetic susceptibilities, cyclic voltammograms, and electronic spectra of the dinuclear iron(II,III) complex, [Fe2(bpmp)(ena)2](BF4)2, were measured and the crystal structure was determined at 293 K, where Hbpmp represents 2,6-bis[bis(2-pyridylmethyl)aminoethyl]-4-methylphenol and Hena is heptanoic acid. The valence states of the irons of the complex are localized below about 200 K in the Mössbauer time scale (10−7 s), and are delocalized above 260 K. The activation energy of the electron interexchange between Fe2+ and Fe3+ was evaluated to be 15 kJ mol−1 at between 200 and 230 K based on an analysis of the Mössbauer spectra. The complex crystallizes in the monoclinic system, space group P2/c, with a = 10.129(4), b = 23.295(30), c = 11.324(7) Å, β = 104.55(4)°, dcalc = 1.34 g cm−3, Z = 2, and molecular formula Fe2F8O5N6C47B2H59. The structure was solved by the heavy-atom method and was refined anisotropically by the least-squares method, employing 1981 unique reflections with |F| > 4σ(Fo). The hydrogen atoms of bpmp were located and refined by an isotropic approximation. The final R and Rw were 7.0 and 8.2%, respectively. The Fe–Fe distance was 3.365 Å, the average Fe–O value 2.033 Å, the average Fe–N value 2.188 Å, and the Fe–O–Fe angle 112.3(4)°. These values support the idea that both iron atoms are in an averaged valence state at 293 K.
  • Tamotsu Sugimori, Hideki Masuda, Osamu Yamauchi
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 131-137
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Structural and spectroscopic studies have been performed on the ternary Cu(II) complexes containing 4-halophenylalanines (XPhe) (X = I or Br) and 2,2′-bipyridine (bpy). The absorption spectra of the 1 : 1 : 1 Cu(bpy)(XPhe) systems exhibited a single d–d peak at 605—608 nm (pH 6—7), and the band centered at ca. 320 nm due to the charge transfer interaction between the substituted phenyl ring and bpy was observed in the difference spectra in the near ultraviolet region. Three complexes with XPhe, [Cu(bpy)(DL-IPhe)(NO3)] (1), [Cu(bpy)(DL-BrPhe)(NO3)] (2), and [Cu(bpy)(L-IPhe)]ClO4 (3) were isolated as crystals, and the structures were determined by the X-ray diffraction method. Complex 1 crystallizes in the monoclinic space group, P21/n, with four molecules in a unit cell of dimensions a = 5.292(1), b = 27.315(8), c = 13.848(2) Å, β = 90.05(2)°. Complex 2 also crystallizes in the monoclinic space group, P21/n, with four molecules in a unit cell of dimensions a = 5.293(5), b = 27.18(1), c = 13.540(6) Å, β = 90.03(6)°. The Cu(II) ion in each complex is in a five-coordinate distorted square-pyramidal geometry. Complex 3 crystallizes in triclinic space group P1 with two independent molecules in the asymmetric unit in a unit cell of dimensions a = 18.329(4), b = 10.701(1), c = 5.9287(9) Å, α = 73.91(1), β = 90.02(2), γ = 105.93(2)°. The Cu(II) ion is in a four-coordinate, slightly distorted square-planar geometry. The phenyl ring of XPhe in 1 and 2 is located perpendicular to the bpy plane, and no intramolecular stacking was observed. The phenyl ring of L-IPhe in 3 is tilted over the coordination plane to be stacked with bpy with the average spacing of 3.23 and 3.24 Å. The crystal structures revealed close contacts between the halogen atoms and the carbon atoms of the bpy ring in complexes 1 and 2, with the distances of I···C = 3.54 Å and Br···C = 3.47 Å for 1 and 2, respectively. A close contact between the iodine and carbonyl oxygen was also detected in the crystal structure of 3 with the I···O distance of 3.1 Å. Possible significance of these interactions has been discussed in relation to thyroid hormone-receptor bonding.
  • Takamitsu Kohzuma, Sohsuke Shidara, Shinnichiro Suzuki
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 138-143
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The cyclic voltammetry of the nitrite reductase from Achromobacter cycloclastes IAM 1013 exhibited well defined voltammetric response at a di-4-pyridyl disulfide (4-pyds) modified gold electrode in the presence of A. cycloclastes apopseudoazurin. The midpoint potential, E1/2, of the native and type II copper-depleted (T2D) nitrite reductase obtained from the voltammogram were estimated to be 240 mV and 204 mV vs. NHE, respectively. The almost identical current value of the native and T2D reductase suggested that the voltammetric behavior contributed from the type 1 copper site. When nitrite was added into the nitrite reductase solution (pH 7.0), an enhanced sigmoidal cathodic current-potential curve indicating the catalytic regeneration of oxidized nitrite reductase was observed. The rate constant of nitrite reduction and the Michaelis constant, Km, of the native reductase were estimated to be 5 × 102 mol−1 dm3 s−1 and 7 × 10−4 mol dm−3, respectively. The rate constant of the nitrite reduction and the Km value of T2D nitrite reductase were also estimated to be 1 × 102 mol−1 dm3 s−1 and 3 × 10−3 mol dm−3, respectively. These results suggested that the nitrite reduction activity is closely related with type II copper site.
  • Mohamed Gaber Marei, Moneim El-Ghanam, Magdi Mohamed Salem
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 144-148
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The polyfunctionalized title triazolyl 1,3-diketones have been prepared by the addition-cyclization reaction of sodium azide to 1,5-diaryl-4-pentyne-1,3-diones, in the first instance, in good yields. These intermediate triazoles can readily be cyclodehydrated to the corresponding 3,6-diaryl-4H-pyrrolo[1,2-c][1,2,3]triazol-4-one derivatives. This cyclodehydration furnishes a new method of synthesis of a new class of pyrrolo[1,2-c][1,2,3]triazoles. The structures of the above compounds were confirmed from their spectral characteristics.
  • Nagwa Rashed, Mahmoud Shoukry, El Sayed H. El Ashry
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 149-155
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The oxidative cyclization of the ethylidene derivative of 3-hydrazinoacenaphtho[1,2-e][1,2,4]triazine (2) gave regioselectively the angular isomer 1-methylacenaphtho[1,2-e][1,2,4]triazolo[3,4-c][1,2,4]triazine (5). Its linear isomer 10-methylacenaphtho[1,2-e][1,2,4]triazolo[4,3-b][1,2,4]triazine (4) was synthesized by the condensation of acenaphthenequinone (6) with 3,4-diamino-5-methyl-4H-1,2,4-triazole. Condensation of 2 with a number of monosaccharides afforded the respective hydrazones 9 whose oxidative cyclization gave the corresponding 1-(polyhydroxyalkyl)acenaphtho[1,2-e][1,2,4]triazolo[3,4-c][1,2,4]triazine (10). Acetylation of 9 and 10 gave 3-[N-acetyl-N′-(polyacetoxyalkylidene)hydrazino]acenaphtho[1,2-e][1,2,4]triazine (11) and 1-(polyacetoxyalkyl)acenaphtho[1,2-e][1,2,4]triazolo[3,4-c][1,2,4]triazine (13) respectively. Periodate oxidation of 9e gave 3-(2-oxoethylidenehydrazino)acenaphtho[1,2-e][1,2,4]triazine (14).
  • Monica Boni, Franco Ghelfi, Ugo Maria Pagnoni, Adriano Pinetti
    1994 年 67 巻 1 号 p. 156-159
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    2-Chloro acid methyl esters were prepared in good yields treating 2-chloro aldehyde dimethyl acetals with trichloroisocyanuric acid in DMF. Aldehyde dimethyl acetals with the 2-halogen on a tertiary carbon atom were poorly reactive and could be oxidized effeciently only after their transformation into 1,3-dioxolanes.
  • Daiyo Terunuma, Koujiro Masuo, Hiroaki Kizaki, Hiroyuki Nohira
    1994 年 67 巻 1 号 p. 160-164
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    A facile cleavage reaction of the germanium–carbon bond of (germylmethyl)amine derivatives to give a germyl anion and an azomethine derivative was developed. The effects of substituents such as phenyl, benzyl, and ethyl groups on the germanium and nitrogen atoms of the (germylmethyl)amine derivatives on the cleavage reaction, were investigated. The mechanism was also investigated based on the stereochemistry of the cleavage reaction using an optically active organogermanium compound.
  • Norio Nishimura, Tatsuya Nakamura, Yoshimi Sueishi, Shunzo Yamamoto
    1994 年 67 巻 1 号 p. 165-171
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The reactions of dibenzoyl peroxide (BPO) with diethylamine (DEA) and diphenylamine (DPA) have been studied by means of an ESR technique combined with spin-trapping. In the case of the DEA/BPO system, diethylnitroxide was formed, while for the DPA/BPO system diphenylaminyl was detected. Three kinds of traps (N-t-benzylidene-t-butylamine N-oxide, 2-methyl-2-nitrosopropane, and 2,4,6-tri-t-butylnitrosobenzene) were used. Different kinds of spin-adducts were formed depending on such conditions as the steric circumstances, radical stabilities and solvent effects. The differences in the reaction mechanisms for these systems are discussed.
  • Masahiro Minabe, Shouji Takeshige, Yuuji Soeda, Takao Kimura, Motohiro ...
    1994 年 67 巻 1 号 p. 172-179
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Bromination and the Friedel–Crafts acetylation of monosubstituted pyrenes were examined. Acetylation of 1-acetyl- and 1-ethylpyrene occurred at the 8-, 6-, or 3-position, but the reaction of 1-methoxypyrene afforded only the 8- and 6-acetyl derivatives. By acetylation, 4-acetylpyrene yielded the 1- and 6-acetyl compounds, and 4-ethylpyrene gave the 6- and 8- derivatives. Also, 4-bromopyrene afforded the corresponding 8-, 6-, and 1-acetyl derivatives by the same reaction. Bromination of 1-ethyl- and 4-ethylpyrene yielded the 8- and 6-bromides, but the reaction of 1-nitro- and 1-bromopyrene took place at the 6-, 8-, or 3-position. The formation ratio of these regioisomers differs by the substituents. The regioselectivity on the acetylation accords in some degree with the prediction based on the 13C NMR chemical shift of each position. The relative rates of these electrophilic substitutions correlate to the substituent constant, σ+, of the substituent attached to the pyrene.
  • Takahiko Akiyama, Hiroyuki Nishimoto, Takaaki Kuwata, Shoichiro Ozaki
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 180-188
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Reduction of an α-keto ester derived from chiral cyclitol, readily available from L-quebrachitol, with K-Selectride proceeded via re-face attack of the ketone with high diastereoselectivity to obtain the α-hydroxy ester in 92% de. On the other hand, reduction of the α-keto ester with K-Selectride in the presence of 18-Crown-6 took place via si-face attack of the ketone to furnish the corresponding α-hydroxy ester in 92% de. Thus both enantiomers of mandelic acid were obtained in optically pure form.
  • Kenji Okada, Hirozo Koyama
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 189-195
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The crystal and molecular structures of the title compound 1 have been determined by direct methods. The crystals are monoclinic, space group P21, with a = 12.512(2), b = 7.436(2), c = 12.252(2) Å, β = 102.62(1)°, Z = 2. The structure was refined by full-matrix least-squares calculations to a final R of 0.056 for 2268 independently observed reflections. This tricylic compound consists of five-, six-, and ten-membered rings and is slightly bent, including two OAc side chains. The six-membered ring A has a typical chair conformation and the ten-membered ring B adopts a chair-chair conformation. Ring C is a normal β envelope. The ring junctions of both A/B and B/C are trans fusion. Two double bonds [C(8)=O(2), C(11)=O(4)] and two methyl groups [C(18), C(19)] of ring B are oriented α face, and one double bond [C(9)=O(3)] is on the β face of this ring. The O–C–O bond distances in the OAc side chains show partial double-bond characters.
  • Toshikazu Ibata, Xinzhuo Zou, Tetsuo Demura
    1994 年 67 巻 1 号 p. 196-202
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Nucleophilic substitution of 2,3,5,6-tetrachloronitrobenzene with secondary amines such as morpholine, piperidine, pyrrolidine, diethylamine, and ethylmethylamine, and primary amines such as aniline, benzylamine, butylamine, isobutylamine, s-butylamine, and t-butylamine, under high pressure of 0.6 GPa at 50 °C for 1—40 h in tetrahydrofuran gave nitro group substitution products together with ortho-mono-, meta-mono-, ortho-ortho-, and ortho-meta-dichloro substitution products. The ratio of these products depends on the bulkiness and amount of amines and the reaction conditions. The selectivity of the nitro group substitution and chlorine substitution depends mainly on the bulkiness of amines.
  • Toshio Itahara, Kazuhiko Imamura
    1994 年 67 巻 1 号 p. 203-209
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The treatment of theophylline, theobromine, and 3-methyluracil with X(CH2)nX (X = Br or I, n = 1—12) in N,N-dimethylformamide containing sodium hydride gave the corresponding 7,7′-(α,ω-alkanediyl)bis[theophylline], 1,1′-(α,ω-alkanediyl)bis[theobromine], and 1,1′-(α,ω-alkanediyl)bis[3-methyluracil]. The interaction of the theophylline, theobromine, and 3-methyluracil rings of these compounds was studied based on their 1H NMR spectra, and stacking of the two purine rings of 7,7′-(α,ω-alkanediyl)bis[theophylline] was observed.
  • Mitsutomo Miyashita, Isamu Shiina, Teruaki Mukaiyama
    1994 年 67 巻 1 号 p. 210-215
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    In the presence of a catalytic amount of active titanium(IV) salt generated in situ from 1 mol of TiCl4 and 2 mol of AgOTf, weakly nucleophilic anilines react under mild conditions with nearly equimolar amounts of silyl carboxylates to afford the corresponding anilides in excellent yields using 4-(trifluoromethyl)benzoic anhydride. The mixed anhydride formed in situ from trimethylsily acetate and 4-(trifluoxomethyl)benzoic anhydride, a key intermediate of this reaction, was detected by 1H NMR experiment. Further, it was shown that the reaction of the mixed anhydrides and 2-nitroaniline was faster than that of the corresponding homo anhydrides and 2-nitroaniline.
  • Wei-Hsien Wang, Hsing-Ching Hsieh
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 216-221
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Proton exchange of N-methyl amides with general acid catalysis in aqueous solution was studied by NMR. Rate coefficients were determined by NMR lineshape analysis of the N-methyl protons. The imidic acid mechanism is favored by amides with electron-withdrawing substituents. Only the imidic acid mechanism is expected to show general acid catalysis, and this mechanism was observed with Brønsted α = 0.16 for the Z proton of N-methylformamide. No general acid catalysis was observed for N-methyl-2-chloroacetamide and N,N′-dimethylmalonamide which exchange protons via the imidic acid mechanism. This result is attributed to their Z conformations.
  • Masao Kawai, Bunsho Makino, Tooru Taga, Yoshihisa Miwa, Tatsuo Yamamot ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 222-226
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    X-Ray crystallographic analysis of two steroid derivatives, 5α,6α-epoxyphysalin B and 2,3-dihydrophysalin B, have been undertaken, revealing their closely similar crystal structures to each other. Their 1H NMR spectra, as well as that of the parent compound physalin B, a 13,14-seco-16,24-cyclosteroid from Physalis alkekengi, have been analyzed based on the crystal structures of these derivatives.
  • Toyoshi Shimada, Rie Hirose, Kensaku Morihara
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 227-235
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Trimethylsilylation with hexamethyldisilazane was applied to a surface modification of silica(alumina) gel catalysts, on which surface the “molecular footprint” catalytic cavities had been marked by the authors’ imprinting method. The modification provided for the more stable catalysts than the unmodified catalyst, retaining their molecular-recognition capabilities nearly intact.
  • Yoko Mori, Naohiko Morishima
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 236-241
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Fluorination reactions of 2-O-benzyl-6-deoxy-1,2-O-isopropylidene-α-D-gluco-, β-L-ido-, α-D-allo-, and β-L-talo-furanoses (1, 2, 3, and 4) were investigated. The reaction of 1 with diethylaminosulfur trifluoride (DAST) predominantly produced 2-O-benzyl-5,6-dideoxy-5-fluoro-1,2-O-isopropylidene-α-D-glucofuranose with the retention of the configuration at C-5. Both of the fluorides with retained and inverted configurations were obtained in the fluorination of 2 with DAST. In contrast, only the inversion of the configuration occurred when 3 and 4 were reacted with DAST. The reactions of the methanesulfonates of 3 and 4 with tetrabutylammonium fluoride (TBAF) and those of their trifluoromethanesulfonates with tris(dimethylamino)sulfonium difluorotrimethylsilicate (TASF) gave the 5-deoxy-5-fluoro derivatives with the inversion of each configuration and the 5,6-unsaturated derivative. However, the reactions of the sulfonates of 1 and 2 overwhelmingly produced the 4,5- and 5,6-eliminated derivatives. For the reaction in which the steric hindrance of the benzyloxyl group at C-3 and the electronic repulsion of ring oxygen to the SN2 displacement with fluoride anion are significant, such as the fluorination of 1 with DAST, the SNi mechansim is reasonable.
  • Hiroshi Yamataka, Kazuyoshi Nishikawa, Terukiyo Hanafusa
    1994 年 67 巻 1 号 p. 242-245
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The carbonyl-14C kinetic isotope effects and the substituent effects on the reactivity of the Zn-promoted Barbier-type reaction of allyl iodide (3-iodo-1-propene) with benzaldehyde and benzophenone were determined in THF at 25 °C. The observed normal carbon isotope effects as well as positive Hammett ρ values suggest that the reactions go through a direct nucleophilic addition mechanism. No indication of the occurrence of electron transfer was obtained by enone isomerization and dehalogenation probe experiments. Diastereoselectivity in the reaction of crotyl iodide (1-iodo-2-butene) with benzaldehyde was low and independent of the substituent on aldehyde, consistent with the six-membered cyclic transition state.
  • Toshiaki Yamashita, Kimiko Tanabe, Katsuhiko Yamano, Masahide Yasuda, ...
    1994 年 67 巻 1 号 p. 246-250
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Photoaminations of 2-alkoxynaphthalenes (1) with ammonia and primary alkylamines were performed by irradiating an acetonitrile–water solution containing 1, an amine, and m-dicyanobenzene to give 1-alkylamino-2-alkoxy-1,4-dihydronaphthalene (2) in relatively good yields. The conversion of 2 to N-acetyl-1-alkylamino-2-tetralones was performed by acetylation with Ac2O followed by a treatment with BF3·OEt2.
  • Kimihisa Yamamoto, Mitsutoshi Jikei, Kenichi Oyaizu, Fumiaki Suzuki, H ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 251-256
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Oxygen-oxidative polymerization of diphenyl disulfides with vanadyl acetylacetonate (VO(acac)2) was studied by the kinetics based on oxygen uptake. Lineweaver-Burk plots reveal that the oxidation of diphenyl disulfide is a rate-determining step for the VO-catalyzed oxidative polymerization of diphenyl disulfide. Km (Michaelis constant) and Vmax were determined to be 1.6 × 10−2 mol dm−3 and 1.5 × 10−4 mol dm−3 min−1, respectively. The polymerization rate is influenced by the oxidation potential of disulfides. The reoxidation step of the catalyst by oxygen is the rate determining step in case of the polymerization of alkyl-substituted disulfides such as bis(3-methylphenyl)disulfide, bis(2,5-dimethylphenyl)disulfide, and bis(3,5-dimethylphenyl)disulfide because the oxidation step of the disulfides is facilitated due to their lower oxidation potentials.
  • Akira Shimoyama, Hiroyuki Ikeda, Shinya Nomoto, Kaoru Harada
    1994 年 67 巻 1 号 p. 257-259
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Mono- and dicarboxylic acids formed from elemental carbon and water by arc-discharge experiments show a systematic decreases along with an increase in the carbon number. The formation of carbon chains of these acids likely proceeded by a progressive additon of one carbon species; this process is discussed in relation to those acids found in carbonaceous chondrites.
  • Yasuo Nakao, Masato Yamashita, Toshiyuki Itoh, Wasuke Mori, Shinnichir ...
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 260-262
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Dinuclear copper(II) complexes, [Cu2(L1)(X)], 14 (X = N3, OH, OAc, pyrazolate(Pz)), [Cu2(L2)(X)], 58 (X = N3, OH, OAc, Pz), [Cu2(L3)(X)], 912 (X = N3, OH, OAc, Pz), and [Cu2(L4)(OH)], 13 have been prepared, where H3L1 is the Schiff base derived from acetylacetone and 1,3-diamino-2-propanol, H3L2 the Schiff base derived from benzoylacetone and 1,3-diamino-2-propanol, H3L3 the Schiff base derived from acetylacetone and 1,5-diamino-3-pentanol, and H3L4 the Schiff base derived from benzoylacetone and 1,5-diamino-3-pentanol. An azide ion bridges in μ-1,3-fashion for 1 (diamagnetic) and 5 with 6-5-5-6 fused-chelate-rings. On the other hand, a μ-1,1-azide bridge has been observed for 9 (coupling constant, J = −126 cm−1, H = −2JS1·S2) with a 6-6-6-6-fused-chelate ring. The relationship between the various physical properties and the structures of fused-chelate rings is discussed.
  • Sardar Ameerunisha, Bhamidi Srinivas, Panthappally S. Zacharias
    1994 年 67 巻 1 号 p. 263-266
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Schiff base ligands derived from the condensation of 2-hydroxy-5-methylbenzene-1,3-dicarbaldehyde with substituted anilines are found to be excellent carriers for the specific transport of copper(II) ions through a liquid membrane.
  • Ki-Young Choi, Ki Sung Kim, Ju Chang Kim
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 267-270
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The dissociation kinetics of DOTRA=H3dotra (1,5,9-triazacyclododecane-1,5,9-triacetic acid) and PETA = H4peta (1,4,8,12-tetraazacyclopentadecane-1,4,8,12-tetraacetic acid) complexes of Ce(III) ion have been studied in an aqueous solution of 0.1 M (NaClO4) at 25.0 ± 0.1 °C using Cu(II) ions as a scavenger. The dissociation rate constant for the acid-catalyzed pathway decreases in the order, [Ce(peta)] > [Ce(dotra)] > [Ce(teta)] > [Ce(nota)] > [Ce(dota)] according to the present and literature data. The rate constant is significantly affected by internal cavity and chelate ring sizes.
  • C. Akira Horiuchi, Eiji Takahashi
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 271-273
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The direct iodination of some ketones using iodine-cerium(IV) ammonium nitrate in acetic acid or acetonitrile gave the corresponding α,α′-diiodoketones in good yield. In the case of cyclododecanone (4), 3-pentanone (5), and 5-nonanone (6), cis- (meso-) compounds [2,12-diiodocyclododecanone (12), 2,4-diiodo-3-pentanone (13), and 4,6-diiodo-5-nonanone (14)] were obtained preferentially.
  • Yutaka Nishigaichi, Noriyuki Ishida, Akio Takuwa
    1994 年 67 巻 1 号 p. 274-276
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Tributyl-(2-pentenyl)tins were readily prepared in high yield by hydrogenation of tributyl-(2,4-pentadienyl)tins with diazene generated from 2,4,6-triisopropylbenzenesulfonohydrazide. The terminal double bond was selectively hydrogenated in the conjugated diene system. The stereochemistry of the internal double bond was completely retained.
  • Akihiko Tsuge, Tetsuji Moriguchi, Shuntaro Mataka, Masashi Tashiro
    1994 年 67 巻 1 号 p. 277-279
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Transannular interaction between two aromatic rings in [2.2]metacyclophanes was estimated by the determination of the stability constants (Ks) for 18-crown-6 complexes with their diazonium salts. It was found out that the Ks is about 10 times as small as that for the corresponding benzenediazonium salt.
  • Masao Hisatome, Jun Watanabe, Koji Yamakawa
    1994 年 67 巻 1 号 p. 280-283
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    The treatment of ferrocenophanes with AgO, Ag2O or AgClO4/CH3ONa in methanol gave oxidized products at the α-methylene of the bridge. In the reaction of [m][n]ferrocenophanes (m, n = 3, 4, 5; m > n), the α-methylene of the longest bridge [m] was oxidized in preference to that of the shorter bridge [n]. A reaction mechanism via a radical and/or cation species on the α-methylene of the bridge is proposed.
  • Michiharu Mitani, Yoshinori Kobayashi
    原稿種別: Accounts
    専門分野: AI
    1994 年 67 巻 1 号 p. 284-286
    発行日: 1994年
    公開日: 2006/07/11
    ジャーナル 認証あり
    Reaction of silyl enol ethers in a system composed of TiCl4, LiAlH4, and CCl4, which generates dichlorocarbene, produced α-chloro-α,β-unsaturated carbonyl compounds in an one-step process.
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