bluuebunny/crossref_metadata_2025 huggingface dataset:
Transition-metal Complexes of Pyrrole Pigments. XV. Coordination of Pyridine Bases to the Axial Sites of Cobalt Corroles
Authors: Murakami Yukito , Yamada Sunao , Matsuda Yoshihisa , Sakata Kazunori
Published: July 2006

Cobalt(III) corroles exist predominantly as polymeric species in a concentration range above 5×10−3 M in chloroform at room temperature as confirmed by NMR measurements. The coordination behavior of pyridine bases at the axial sites of cobalt(III) corroles, in a concentration range where they are present exclusively in the monomeric species, has been investigated by measuring electronic spectra in acetone at 25.0±0.1 °C. Penta- and hexa-coordination processes were found to take place, and the stepwise formation constants were interpreted by means of the equations logKi=a·pKa+b and logKi⁄Ki0=ρσ. When the cobalt corrole was reduced at the nuclear cobalt from trivalent to bivalent state, only one pyridine molecule was coordinated at its axial sites, hexa-coordination being no longer possible as confirmed by ESR measurements. The axial ligation behavior of cobalt corroles is quite analogous in nature to that of cobalt corrinoid.
An Investigation on the Effect of Structural Variation on Thermal Decomposition of Rare Earth Chromates(V)
Authors: Roy Ajoy , Chaudhury M , Nag K
Published: July 2006

Non-isothermal decomposition kinetics of LaCrO4, PrCrO4, and NdCrO4 have been investigated. In each case, first order decomposition takes place. The energy of activation, Ea* has been evaluated by applying five different computational procedures based on the data of TG, DTA, and DTG. These values are fairly in good agreement with each other and the average activation energies per mole of the compounds are : LaCrO4: 240 kcal, PrCrO4: 180 kcal and NdCrO4: 170 kcal. The above trend in Ea* has been rationalized by taking into consideration the packing of atoms in rare earth chromates(V).
Gas Phase Photochemical Reactions of Nitrogen Dioxide. Effect of Oxygen on the Conversion of Benzene into Nitrobenzene
Authors: Watanabe Kazuo , Ishikawa Hiroshi , Ando Wataru
Published: July 2006

Gas phase photochemical nitration of benzene with nitrogen dioxide in the presence of oxygen was studied. Conversion of benzene into nitrobenzene was drastically accelerated by oxygen.
Preparation of Aroyl and Arenesulfonyl Fluorides from the Corresponding Chlorides Using Zinc Fluoride–Pyridine System
Authors: Sekiya Akira , Ishikawa Nobuo
Published: July 2006

Convenient preparation of aroyl and arenesulfonyl fluorides in high yields was achieved by the reaction of the corresponding chlorides with zinc fluoride in pyridine.
Metal-ion Complexation of Noncyclic Poly(oxyethylene) Derivatives. II. PMR Studies of the Complexation with Alkali and Alkaline-earth Metal Cations
Authors: Yanagida Shozo , Takahashi Kazutomo , Okahara Mitsuo
Published: July 2006

The complexation of homogeneous polyethylene glycols and their dimethyl ethers(glymes) with alkali and alkaline-earth metal cations was studied by PMR spectroscopy on the basis of a comparison with crown ethers. The ethylene proton signal of octaethylene glycol in methanol-d4 was split into three lines by the addition of a potassium, rubidium, caesium, strontium, or barium cation. The latter two cations also caused large downfield shifts of the signals, which are quite comparable with those of 15-crown-5 and 18-crown-6 caused by the same metal cations. As for heptaethylene glycol, a splitting was observed in the presence of a strontium ion or an alkali metal cation except for a lithium ion. A large downfield shift was also observed in the presence of a strontium or barium ion. As for hexaethylene glycol, the signal was split only by a sodium ion, and the optimal interaction with a calcium ion was confirmed on the basis of the downfield shift. In methanol-d4, lithium and magnesium ions did not cause any change in the PMR spectra of either the crown ethers or the glycols. The PMR downfield-shift method also disclosed the metal-ion complexation of the glycols in water. The terminal hydroxyl groups play an important role in the complexation.
Linear Response Polarizability Theory of the UV, ORD, and CD Bandshapes of Helical Biopolymers. Single- and Double-Stranded Polyadenylic Acids
Authors: Ito Hirotoshi , I’Haya Yasumasa J , Eri Toshiyuki
Published: July 2006

The UV, ORD, and CD spectral bandshapes of polyadenylic acid (poly A) have been investigated theoretically in order to challenge the problems of whether discrimination of the single- and double-stranded poly A’s is computationally possible and of what structure poly A holds in a neutral solution. A linear response polarizability theory is applied to the derivation of UV, ORD, and CD bandshape functions of a polymer composed of N identical monomers. Using the observed and/or assumed values for the spectral bandshape of the adenine monomer, the UV, ORD, and CD spectra of both single- and double-stranded poly A’s are calculated by changing geometrical parameters. The single-stranded poly A at neutral pH is assumed to have a regular helical structure which is regarded as a counterpart of the double helix form of the double-stranded poly A. This model leads to the chainlength (N) effect which in turn suggests that the structure of poly A in a neutral solution is very flexible and is such that it can be approximated as a random assembly of adenine dirners and/or trimers, when the theoretical spectra of both the single- and double-stranded poly A’s are compared.
ESR Study of Hot Ions in Solid Solutions of K2[(Zn,Cd,Hg)(CN)4]
Authors: Kozlowski Henryk , Isoya Jun-ichi , Fujiwara Shizuo
Published: July 2006

The ESR spectra of Cd(I) hot ions produced in solid solutions of K2[(Zn, Cd, Hg)(CN)4] indicate that there are paramagnetic species of hot-ion molecules characteristic of the single phase of K2[Zn(CN)4] and of the solid solution. The total contribution from the s and p orbitals to the spin density of the Cd(I) hot ions is constant, although the relative contributions from these two orbitals vary. It is shown that the mother lattice surrounding the hot ions determines the electronic structure and stability of the hot ions. These results suggest that the investigation of hot ions in a solid solution is useful for the study of microstructure of the solid solution.
Preparation and Isomerization of Three Isomers of l-Histidinatoiminodiacetatocobalt(III) Complex
Authors: Watabe Masatoshi , Zama Masayuki , Yoshikawa Sadao
Published: July 2006

Three isomers of l-histidinatoiminodiacetatocobalt(III) complex have been prepared and characterized on the basis of their absorption, circular dichroism and proton magnetic resonance spectra. These isomers isomerized mutually in water at 80 °C. The equilibrium mole fractions of these isomers in water were found for cisN, transN and fac to be 0.91, 0.04, and 0.05, respectively.
Kinetics and Mechanisms of the Reduction of Cobalt(III) Complexes by the Chromium(II) Complex Ligating N-(2-Hydroxyethyl)ethylenediamine-N,N′,N′-triacetate
Authors: Ogino Hiroshi , Shimura Makoto , Tanaka Nobuyuki
Published: July 2006

The reduction of the cobalt(III) complexes, CoX(NH3)5(3–m)+ (Xm−=Cl−, Br−, NCS−, and H2O) and Co(en)33+, by Cr(II)–HEDTRA was studied by the stopped-flow method, where en and HEDTRA denote ethylenediamine and N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetatic acid respectively. From the kinetic behavior and the spectral properties of the immediate chromium(III) products, it is concluded that the Cr(II)–HEDTRA reductions of CoX(NH3)52+ (X−=Cl−, Br−, and NCS−) are of an inner-sphere type. The effect of the HEDTRA coordinated to chromium(II) on the rates of the electron-transfer reactions is discussed.
The Intrachain Aminolysis of a Terminal p-Nitrophenyl Ester Group by a Terminal 4-Pyridyl Group Attached to Both Ends of a Poly(oxyethylene) Chain
Authors: Sisido Masahiko , Yoshikawa Eiichi , Imanishi Yukio , Higashimura Toshinobu
Published: July 2006

The intrachain aminolysis by a terminal 4-pyridyl group of a p-nitrophenyl ester group at the other terminal of a poly(oxyethylene) chain was investigated. The rate constants of the intrachain reaction were determined as a function of the degree of polymerization, n, of the poly(oxyethylene) chain over the range of 5–33 at 15, 25, and 35 °C. The rate constant was at its maximum at n=7 and decreased with an increase in the chain length. A comparison of the data with those obtained with polysarcosine chain showed that the intrachain reaction proceeded more effectively in the latter chain. Some thermodynamic considerations were made as to the cyclization process of a poly(oxyethylene) chain.
The Role of the Charge-transfer Complex in the Photocopolymerization of Oxygen with Styrene and α-Methylstyrene
Authors: Kodaira Toshiyuki , Hashimoto Kohzoh , Sakanaka Yoshihiko , Tanihata Sumio , Ikeda Katsuki
Published: July 2006

The effect of the wavelength of irradiated light on the photocopolymerizations of oxygen with styrene (1) and α-methylstyrene (2) was investigated in connection with the charge-transfer bands observed between these monomers and oxygen, with the latter as an electron acceptor. It appeared that the excitation of the charge-transfer bands is responsible for the copolymerizations and that the photoabsorptions due to 1 and 2 do not contribute to the reactions, although the excited singlet states of these compounds were quenched by oxygen according to a Stern-Volmer plot.
Studies on the Liquid Phase Oxidation of Nitroalkylbenzenes Catalyzed by Transition Metal and Bromide Ions
Authors: Hasegawa Ryoichi , Kamiya Yoshio
Published: July 2006

The liquid phase autoxidation of nitroalkylbenzenes catalyzed by transition metal and bromide ions in acetic acid was investigated at 55–85 °C. A remarkable synergistic effect was found on the mixtures of metal catalysts composed of cobalt and other transition metals, the maximum reaction rate being observed at the molar ratio of Co : Mn : Br=1 : 0.005–0.01 : 1–2. The rate of oxygen absorption of p- or m-nitroalkylbenzenes wasas affected by the partial pressure of oxygen, showing deviation from the first order dependency on the substrate concentration in contrast to the case of ordinary alkylbenzenes. The results can be explained by the retardation effect due to nitro compounds which might result from the reaction with alkyl radicals and the deactivation of metal catalysts. o-Nitroalkylbenzenes except nitroethylbenzene show a great resistivity against the oxidation. The retardation effect can be ascribed to the inhibiting effect due to inactive free radicals and also to the various reduced products resulting from the intramolecular reaction of nitro groups and active radicals. It was found that the autoxidation of p-nitrotoluene catalyzed by Co–Mn–Br catalyst proceeds very rapidly at temperatures as low as 85 °C, yeilding mostly p-nitrobenzoic acid along with a small amount of p-nitrobenzaldehyde.
Surface Tensions of Several Rare-earth Chlorides and Binary NaCl–YCl3 System in Molten State
Authors: Igarashi Kazuo , Mochinaga Junichi , Ueda Shiro
Published: July 2006

The surface tensions of YCl3, LaCl3, PrCl3, NdCl3, GdCl3, and DyCl3, and binary NaCl–YCl3 system in molten state were measured by a maximum bubble pressure method, and the results were represented by empirical formulas as functions of temperature. Surface enthalpies of rare-earth chlorides were calculated from the formulas.
The Separation of Iron(III), Cobalt(II), Nickel(II), Copper(II), Zinc(II), Mercury(II), Lead(II), Cadmium(II), and Palladium(II) as Their SDBM (3-Mercapto-1,3-diphenyl-2-propen-1-one) Complexes by Thin Layer Chromatography on Silica Gel
Authors: Honjo Takaharu , Honnami Hiromi , Kiba Toshiyasu
Published: July 2006

The separation of iron(III), cobalt(II), nickel(II), copper(II), zinc(II), mercury(II), lead(II), cadmium(II), and palladium(II) as their SDBM chelates has been achieved successfully on the thin layer of silica gel with such developing solvents as carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and carbon disulfide.
An X-Ray Photoelectron Spectroscopic Study of Biuret Metal Complexes
Authors: Yoshida Tooru , Yamasaki Kiyoshi , Sawada Shigemasa
Published: July 2006

The mode of the co-ordination of biuret in biuret metal complexes has been examined by means of X-ray photoelectron spectroscopy. It has been found that the C(1s), O(1s), and N(1s) binding energies were clearly different among the bidentated, O-, and N-co-ordinated structures, and the monodentated O-co-ordinated one.
Electrosynthesis of Hetero-Hetero Atom Bonds. I. A Direct Preparation of Bis(dialkylthiocarbamoyl) Disulfides from Dialkylamines and Carbon Disulfide
Authors: Torii Sigeru , Tanaka Hideo , Misima Kiyosi
Published: July 2006

Bis(dialkylthiocarbamoyl) disulfides were synthesized directly from dialkylamines and carbon disulfide by electrolysis under constant voltage using an undivided cell. The electrochemical reaction was carried out effectively in a two-layer system of electrolysis solvents, e. g., water–chloroform, water–dichloromethane, water–1,2-dichloroethane, and water–carbon disulfide. Likewise, the electrolysis could be performed in a homogeneous solution using dimethylformamide and/or acetonitrile.
Beam Studies of the Ion-Molecule Reaction CO2++D2→DCO2++D
Authors: Tochihara Hiroshi , Murata Yoshitada
Published: July 2006

Reaction cross sections of the reaction CO2++D2→DCO2++D have been measured over the range of the collision energies E=0.4 to 4 eV in the center of mass system. The cross section was obtained from relative values of the reaction Ar++D2→DAr++D by using the mixed ion beam method. The observed cross sections are about half of the Langevin-Gioumousis-Stevenson cross sections and show approximately E−1⁄2 dependence.
The Structure of the Cyclodextrin Complex. VI. The Crystal Structure of α-CycIodextrin–m-Nitrophenol (1 : 2) Complex
Authors: Harata Kazuaki , Uedaira Hisashi , Tanaka Jiro
Published: July 2006

α-Cyclodextrin (α-CDx) forms a 1 : 2 crystalline complex with m-nitrophenol (m-NP). The crystal structure was determined by the X-ray method. The crystal is orthorhombic, and the space group is P21212 with Z=2. The cell dimensions are a=22.231(7), b=16.865(6), and c=8.152(1) Å. The structure was solved on the basis of the nearly isomorphous structure of the α-CDx-sodium benzenesulfonate complex by using 2246 reflections, and refined by the block-diagonal least-squares method to the final R-value of 0.10. The framework of the crystal is built up of a stack of α-CDx molecules with a head-to-tail arrangement along the two-fold axis, showing a channeltype structure. Two m-NP molecules are statistically disordered on the two-fold axis. One is located in the channel, while the other is sandwiched between the α-CDx molecules. In the channel, the nitro group of m-NP is inserted into the α-CDx ring from the secondary hydroxyl side, and the phenolic hydroxyl group is hydrogen-bonded to the primary hydroxyl group of the next α-CDx molecule. The enthalpy change was calculated for the complex formation in an aqueous solution. The calculated results are in qualitatively agreement with the observed values. The catalytic ability of α-CDx in the hydrolysis of substituted phenyl acetates was discussed on the basis of the structural data.
The Structure of the Cyclodextrin Complex. VII. The Crystal Structure of the α-Cyclodextrin–DMSO–Methanol(1 : 1 : 2) Dihydrate Complex A Simultaneous Inclusion of DMSO and Methanol
Authors: Harata Kazuaki
Published: July 2006

The crystal structure of the α-cyclodextrin(α-CDx)–DMSO–methanol (1 : 1 : 2) dihydrate complex was determined by the X-ray method. The crystal is monoclinic, and the space group is P21 with Z=2. The cell dimensions are a=9.505(1), b=14.150(1), c=19.738(2) Å, and β=102.88(1)°. The structure was solved by an inspection of a Patterson map and by a trial-and-error method, and was refined by the block-diagonal least-squares method to the final R-value of 0.083 for 3732 reflections. The α-CDx ring is nearly hexagonal, with diagonal distances of 8.40–8.53 Å between the glycosidic oxygen atoms. The α-CDx molecules are arranged to form molecular layers perpendicular to the ac plane. The DMSO molecule is located on the secondary hydroxyl side in the α-CDx cavity, forming two hydrogen bonds with the adjacent α-CDx molecules. One methanol molecule is found on the primary hydroxyl side in the cavity, while the other is located outside the cavity. Two water molecules are distributed in the space between α-CDx molecules.
The Crystal and Molecular Structures of Pyrrolidinium p-Chlorobenzoate and Pyrrolidinium p-Toluate
Authors: Kashino Setsuo , Kataoka Shin-ichi , Haisa Masao
Published: July 2006

The crystal structures of pyrrolidinium p-chlorobenzoate (PYC) and pyrrolidinium p-toluate (PYT) have been determined from visually estimated Cu Kα data. The crystals of PYC are orthorhombic, space group Pbca, a=9.53(1), b=27.28(3), c=9.39(2) Å, and Z=8. Those of PYT are monoclinic, space group P21/c, a=14.66(3), b=9.00(2), c=9.44(1) Å, β=101.3(4)° and Z=4. The structures of PYC and PYT were refined by the blockdiagonal least-squares method to R values of 0.073 and 0.089 for 855 and 1277 non-zero reflections, respectively. In both PYC and PYT, the pyrrolidinium and benzoate ions are linked together by two kinds of N–H…O hydrogen bonds to form a ribbon along the twofold screw axis. The shorter hydrogen bond [N…O 2.697(7) Å for PYC, 2.674(5) Å for PYT] lies nearly perpendicular to the twofold screw axis, and the longer bond [N…O 2.730(7) Å for PYC, 2.738(5) Å for PYT] makes an angle of about 20° with the axis. The O…N…O angle is near to the regular tetrahedral angle [105.4(2)° for PYC, 107.1(2)° for PYT]. The crystals of PYG are isomorphous with those of piperidinium p-chlorobenzoate, piperidinium p-bromobenzoate, piperidinium p-toluate and pyrrolidinium p-bromobenzoate, but PYT crystallizes in a subgroup of the space group of the others because of the cooperative effects of the bulkiness of the methyl group and the ring size of the base moiety. The pyrrolidine rings in PYC and PYT take an approximate CS symmetry.
Reactions between PbO and TiO2 under Hydrothermal Conditions
Authors: Kaneko Shoji , Imoto Fumio
Published: July 2006

The phase relation of products obtained by the reaction between PbO and TiO2 under hydrothermal conditions up to 500 °C and 500 kg/cm2 for 5h has been investigated. The yield and crystallographic properties of purified PbTiO3 depend upon the PbO/TiO2 mole ratio (Pb/Ti ratio) in raw mixtures as well as the reaction temperature. Both PbTiO3 and PbTi3O7 are synthesized at a remarkably low temperature under hydrothermal conditions, as compared with the ignition process in air. Pure and well-crystallized PbTiO3 is obtained by heat-treating above 400 °C at Pb/Ti ratios greater than 1.0 and by dissolving excess PbO with acetic acid. PbTi3O7 coexists occasionally with PbTiO3 to some extent at Pb/Ti ratios less than 1.0, but appears as a single phase in the temperature range 100–450 °C at the Pb/Ti ratio 0.33. The unit cell volume of PbTiO3 prepared at lower temperature is considerably large, suggesting a loosely-packed structure. The compound is always of tetragonal form containing no metastable cubic form.
Aromaticity-Based Theory of Pericyclic Reactions
Authors: Aihara Jun-ichi
Published: July 2006

The resonance energies of conjugated compounds in the electronically excited state were calculated on the basis of the aromaticity theory previously reported by us. The allowednesses of pericyclic reactions were predicted by means of these resonance energies. The predictions based on the resonance energy difference (RED) between the pericyclic transition state and the reactant(s) are in general agreement with the experiment.
The Reaction of N-AIkylisoxazolium Salts with Hydroxylamine
Authors: Kashima Choji , Arai Kimio , Imada Satoshi , Tsuda Yoshihiko
Published: July 2006

The alternating transposition of C-3 and C-5 substituents on 3,5-disubstituted isoxazoles was found by refluxing a mixture of hydroxylamine hydrochloride, potassium carbonate, and 3,5-disubstituted 2-methylisoxazolium salts, derived from the corresponding isoxazoles. Under the same conditions, 3,5-disubstituted 2-t-butyl- or 2-benzhydrylisoxazolium salts gave the corresponding isoxazoles without alternation of the substituents.
An Anion Radical Precursor in the Nucleophilic Substitution of p-Dinitrobenzene
Authors: Abe Takehiro , Ikegami Yusaku
Published: July 2006

Appearance of p-dinitrobenzene anion radical has been demonstrated by visible and ESR spectroscopy in the replacement of the one nitro group of p-dinitrobenzene by hydroxide ion in aqueous dimethyl sulfoxide. The formation of the anion radical seems to be due to the direct electron transfer from hydroxide ion to p-dinitrobenzene. The results of kinetic studies suggest that the anion radical is a precursor in the substitution reaction.
Gel Filtration Study of the Effect of Urea on the Dissolution State of Sodium Dodecyl Sulfate
Authors: Sasaki Tsunetaka , Amano Hiroshi , Suzuki Hitoshi
Published: July 2006

Using gel columns of Sephadex G 50 Fine and CPG gel, gel filtration studies were made of the sodium dodecyl sulfate (SDS)–urea system. The results demonstrated that both the CMC and the elution volume of SDS were increased by the addition of urea. The increase of the elution volume indicates the decrease in micellar size, and this coupled with the increase of CMC indicates the increased difficulty of micelle formation by the addition of urea. The direct interaction between SDS and urea was also examined by the gel filtration method and such interaction was confirmed to be absent both below and above the CMC of SDS. Furthermore, the micellar weight of SDS was estimated by the gel filtration method and values of 23000 and 11000 were obtained for SDS solutions containing 0 and 3 mol dm−1 urea, respectively.
The Preparation of Phosphonic Acids Having Labile Functional Groups
Authors: Morita Tsuyoshi , Okamoto Yoshiki , Sakurai Hiroshi
Published: July 2006

Phosphonic acids having labile functional groups have been prepared quantitatively by the hydrolysis of bis(trimethylsilyl) phosphonates, were prepared by the reaction under mild conditions of the corresponding dialkyl phosphonates with bromotrimethylsilane.
Electroorganic Chemistry. XXVI. Electrooxidation of Enamines, Haloolefins, and Enol Ethers
Authors: Shono Tatsuya , Matsumura Yoshihiro , Hamaguchi Hiroshi , Imanishi Tamotsu , Yoshida Kaoru
Published: July 2006

Electrooxidation of enamines in methanol afforded two types of methoxylated enamines. Similar treatment of enol ethers gave trimethoxylated compounds. The products formed by the electrolysis of haloolefins in acetic acid were α-acetoxy haloolefins and α-acetoxy ketones.
Carrier Effect on the Nature of V4+ and Active Oxygen Species in Vapor-phase Oxidation of Butadiene over Supported Divanadium Pentaoxide Catalysts
Authors: Akimoto Masamichi , Usami Masahiro , Echigoya Etsuro
Published: July 2006

The reactivity of V4+ with gaseous oxygen formed on various kinds of supported V2O5 catalysts has been investigated by ESR. The results are discussed as carrier effect in relation to the selectivity for maleic anhydride formation during the course of the vapor-phase oxidation of butadiene. V4+ formed on Al2O3 (V/Al≤10/90 atom ratio) and MgO (V/Mg≤30/70) showed a hyperfine ESR structure and was hardly oxidized whereas V4+ formed on SiO2 (V/Si≥5/95) had the singlet ESR signal and was easily oxidized. Formation of these two kinds of V4+ was observed on V2O5–Al2O3 (V/Al≥20/80). They were similarly observed in the case of V2O5-TiO2, but some portion of V4+ having the hyperfine structure was also oxidized. The selectivity was high over the catalysts forming the reactive V4+ as compared with those forming the unreactive one. The reactive V4+ was shown by X-ray diffraction to be preferentially formed in crystalline V2O5. Study of the reduction and reoxidation of unsupported crystalline V2O5 by means of IR and the effect of addition of alkali metal oxide on the catalytic activity of the supported V2O5 were discussed. The important role of double bond type lattice oxygen V=O in maleic anhydride formation was proposed.
A Redetermination of Diphenanthro[5,4,3-abcd: 5′,4′,3′-jklm]perylene
Authors: Oonishi Isao , Fujisawa Shoji , Aoki Junji , Danno Takaaki
Published: July 2006

It has been shown that the true unit cell of diphenanthro[5,4,3-abcd: 5′,4′,3′-jklm]perylene consists of three subcells in which the atomic arrangements differ slightly from each other. The model for the ordered structure has been deduced from the consideration of weak reflections. The average structure of the subcell with a=30.80, b=3.837, c=19.87 Å, β=112.5°, and Z=4 has been redetermined. The final R value is 0.103 for 1244 independent reflections. The two naphthanthrone planes in the molecule make an angle of 36°, which shows a large distortion from a planar structure.
Catalysis by Supported Metal Crystallites from Carbonyl Clusters. II. Catalytic Ethanol Synthesis from CO and H2 under Atmospheric Pressure over Supported Rhodium Crystallites Prepared from Rh Carbonyl Clusters Deposited on TiO2, ZrO2, and La2O3
Authors: Ichikawa Masaru
Published: July 2006

Ethanol was catalytically produced in the CO–H2 reaction under atmospheric pressure and at 150–250 °C over rhodium crystallite catalysts prepared from Rh carbonyl cluster compounds highly dispersed on La2O3, TiO2, and ZrO2. The activity and selectivity of ethanol formation depend on the kind of metal carbonyl cluster and metal oxide used as inorganic carriers. The catalysts prepared by the pyrolysis of smaller Rh carbonyl clusters such as Rh2(C5H5)2(CO)3, Rh4(CO)12, and Rh6(CO)16 on La2O3, TiO2, and ZrO2 show higher selectivity of the oxygenated products containing ethanol (main), acetaldehyde, and methanol. The ethanol contents in the oxygenated products increased considerably above 200 °C over the catalysts. CeO2 and ThO2 were also employed in the preparation of the pyrolysed catalysts to disperse the Rh carbonyl clusters, which catalyses the ethanol formation in the CO–H2 reaction at atmospheric pressure.
Azafulvenes 8. Cycloaddition Reaction of 8-Azaheptafulvene to Sulfene
Authors: Iwasaki Takahiko , Kajigaeshi Shoji , Kanemasa Shuji
Published: July 2006

Peri- and stereoselective cycloadducts were obtained from the reactions of 8-aryl-8-azaheptafulvenes with some sulfenes. 8-Aryl-8-azaheptafulvenes reacted with phenylsulfene to give cis [8+2] cycloadducts as the sole products which would have resulted either from the endo approach or via the endo intermediate of the two reagents. On the other hand, with benzoylsulfene trans [8+2] cycloadducts were isolated. The formation of the latter products was rationalized by considering epimerization of the initially formed cis adducts. The cis [8+2] cycloadducts to vinylsulfene did not give the trans isomers but the hydrogen migrated derivatives under the influence of bases. The mechanism of the above reactions is also discussed.
Catalytic Activities of Salicylaldehyde Derivatives. VIII. Kinetic Studies of the Catalytic Racemization of l-Glutamic Acid at 25 °C
Authors: Ando Makoto , Emoto Sakae
Published: July 2006

The racemization of l-glutamic acid catalyzed by 15 kinds of salicylaldehyde derivatives has been kinetically studied at 25 °C and pH 10 in the presence of copper(II) ion. When 4- and 5-substituted salicylaldehydes were used as the catalyst, Hammett’s plots for the racemization against σ− were found to be linear with fewer points deviating from the line than the plots against σ . This fact has not been observed previously, since the salicylaldehyde derivatives tested having a substituent of different value between σ and σ− were degraded during the course of reaction at 80 °C. Hammett’s plots for the reaction catalyzed by 3-substituted salicylaldehydes indicated no linear relation with either σ or σ−. These catalytic racemizations, including the case of the 6-substituted salicylaldehydes have been discussed.
Incorporation of CO2 in Butadiene Dimerization Catalyzed by Palladium Complexes. Formation of 2-Ethylidene-5-hepten-4-olide
Authors: Inoue Yoshio , Sasaki Yoshiyuki , Hashimoto Harukichi
Published: July 2006

Reaction of carbon dioxide with butadiene catalyzed by palladium–phosphine complexes was studied. When the reaction was carried out in certain polar, aprotic solvents, such as dimethylformamide (DMF), 2-ethylidene-5-hepten-4-olide was formed in about 5% yield by the incorporation of CO2 together with the formation of butadiene linear dimers. The main dimer was 1,3,7-octatriene. The ditertiary phosphines, R2PCH2CH2CH2PR2 where R is methyl or phenyl, were found to be suitable as the ligand for the olide synthesis. A possible mechanism involving the intermediate of π-allyl, σ-allyl form from two moles of butadiene and the palladium complex is proposed.
Glass Formation in the Li2O–TiO2–P2O5, MgO–TiO2–P2O5, and CaO–TiO2–P2O5 Systems
Authors: Kishioka Akira
Published: July 2006

The glass-forming regions in the Li2O–TiO2–P2O5, MgO–TiO2–P2O5, and CaO–TiO2–P2O5 systems have been determined. Homogeneous glasses were formed with compositions of less than 50 mol% P2O5 in all three systems. The largest quantities of TiO2 could be introduced into glass for compositions of 30 mol% P2O5. In compositions with more than 50 mol% P2O5 only a mixture of the glass and crystal was formed. With an increase in the TiO2 content, the density of the glass increased and the volume per mole of oxygen decreased. These results indicate that the TiO2 had been easily incorporated into the glass with compositions of lower P2O5 contents, contributing to the stabilization of the glass structure.
Reduced Copper Catalyzed Conversion of Primary Alcohols into Esters and Ketones
Authors: Takeshita Kenji , Nakamura Shigeaki , Kawamoto Kazuaki
Published: July 2006

Vapor phase reactions of a mixture of two types of primary alcohols to esters and ketones over a reduced copper catalyst have been investigated. The reactions between primary alcohols and propionaldehyde have also been investigated. The effects of the molar ratio of the reactants and the reaction temperature on the yields of esters, ketones, and aldehydes have been examined. A mixture of ethyl alcohol and propyl alcohol when passed over the catalyst, the main products have been found to be propyl acetate, ethyl acetate, propyl propionate, ethyl propionate, ethyl methyl ketone, diethyl ketone, acetone, acetaldehyde, and propionaldehyde. The formation of the ester and the ketone may be presented as follows:

(Remark: Graphics omitted.)
Photoreduction of 1-Benzyl-3-carbamoylpyridinium Chloride in Aqueous Ammonia
Authors: Matsuura Teruo , Itahara Toshio , Otsuki Toshiaki , Saito Isao
Published: July 2006

Irradiation of 1-benzyl-3-carbamoylpyridinium chloride (BNA+Cl−) in the presence of ascorbic acid in 28% aqueous ammonia gives the corresponding 1,4-dihydronicotinamide as the major product. The spectroscopic behavior of BNA+ in aqueous ammonia and the adduct formation between BNA+ and chloroform are also described.
Physical Properties and Constitution of the 5,6 : 11,12-Bis(epidithio)naphthacene–Iodine Complexes (TTT–In)
Authors: Inabe Tamotsu , Matsunaga Yoshio
Published: July 2006

The electrical resistivity of the 5,6 : 11,12-bis(epidithio)naphthacene(TTT)–iodine system was examined using poly crystalline compactions. The room-temperature resistivity reaches a minimum of 0.3 ohm cm at the composition of the well-studied metallic phase, TTT–I1.5, and a shoulder as large as 200 ohm cm occurs at the composition of the other metallic phase, TTT–I2.7. The apparent activation energy for semiconduction at the latter composition is as much as 0.13 eV, indicating some semiconductor behavior in directions other than the needle axis. The appearance of the latter phase is also manifested by a drastic increase in the Seebeck coefficient near this composition, which corresponds to a change in the amount of charge per TTT molecule from 0.68 to 0.85. The diffuse reflection spectra were recorded for TTT–I1.53 and TTT–I2.79. The resemblance between the spectrum of the iodine-rich complex and that of TTT–Br is noted.
The G-value of Nitrogen Atoms Produced in the γ-Radiolysis of Liquid Nitrogen and the Ozone Formation in the γ-Irradiated Liquid Nitrogen Solution of Oxygen
Authors: Matsumoto Akihiko , Yugeta Rei , Karasawa Hidetoshi , Sato Shin
Published: July 2006

The γ-radiolyses of liquid nitrogen solutions of nitrogen oxide and of oxygen gave nitrogen dioxide and ozone, respectively, as the main products. Over the solute concentrations from 0.01 to 0.1 mol l−1, the G-values of both products were constants: G(NO2)=3.3 and G(O3)≈7. The G-value of nitrogen dioxide in the former solution probably corresponds to the G-value of nitrogen atoms from liquid nitrogen. For the formation of ozone in the latter solution, a possible reaction mechanism is discussed. Dinitrogen oxide was found as a minor product, the G-value being about 0.1 for both solutions.
Cobalt(IV) Ammine Complexes with 5-Nitrosalicylato or Similar Ligands. IV.) Preparation, 1H-NMR, 13C-NMR, and IR Spectra
Authors: Yamamoto Yoshihisa
Published: July 2006

The 1H-NMR spectrum of the 5-nitrosalicylatotetraamminecobalt(IV) complex did not show the signals of phenyl protons of the salicylato ligand, but did show those of ammine protons at 3.7 (s, 6H) and 3.3 ppm (s, 6H). The 13C-NMR peaks could not be observed because of the paramagnetism. The 1H-NMR spectra of the salicylatotetraamminecobalt(III) complexes showed peaks at 3.96 (s, 6H), 3.65 (s, 3H), and 3.38 ppm (s, 3H) for the ammine protons and at 6.7–8.1 ppm (m, 4H) for the phenyl protons of the salicylato ligand. Their 13C-NMR spectra showed seven signals for the salicylato ligand. The IR peaks assignable to the rocking deformation vibration were observed at 830–855 cm−1 for the ammine ligands of 5-nitrosalicylatotetraamminecobalt(IV) complexes and at 820–840 cm−1 for those of salicylatotetraamminecobalt(III) complexes, in conformity with the view that the former complexes are actually cobalt(III) complexes of a free radical nature.
Reduction by a Model of NAD(P)H. XVII. Isotope Effects and Magnesium Ion Catalysis
Authors: Ohno Atsuyoshi , Yasui Shinro , Yamamoto Hiroyuki , Oka Shinzaburo , Ohnishi Yutaka
Published: July 2006

The reduction of thiopivalophenone (1) with 1-benzyl-1,4-dihydronicotinamide (BNAH) gives the same value for kinetic deuterium isotope effect (kH⁄kD) and isotopic distribution in the product (YH⁄YD) regardless of the presence or absence of magnesium ion. The reduction of methyl benzoylformate (2) with a BNAH-analog in the presence of magnesium ion also gives similar values for kH⁄kD and YH⁄YD. It has been concluded that magnesium ion stabilizes the transition state in the reduction of 2, whereas an intermediate is stabilized by magnesium ion in the reduction of 1.
Layered Compounds. LII. Syntheses of Eleven Anthracenophanes
Authors: Iwama Akio , Toyoda Toshihiro , Yoshida Misaku , Otsubo Tetsuo , Sakata Yoshiteru , Misumi Soichi
Published: July 2006

A series of layered cyclophanes where an anthracene ring is stacked in different modes with the same or other π-systems has been synthesized by the Hofmann elimination method or photodesulfurization for studying the transannular π-electronic interaction. Photochemical and thermal interconversions have been observed between syn-(1,4)anthracenophane and its isomer and have been discussed with reference to the X-ray crystal data. From the electronic spectra it has been established that the transannular interaction increases with overlapping between the two faced aromatic rings and that when the overlap between the two chromophores is the same, the interaction increases relative to the dimension of the faced chromophore.
Sulfenylation Accompanied by Dealkoxycarbonylation of β-Keto Esters, Geminal Diesters, and α-Cyano Ester in Hexamethylphosphoric Triamide (HMPA)
Authors: Asaoka Morio , Miyake Kazutoshi , Takei Hisashi
Published: July 2006

In the presence of sodium iodide, diphenyl disulfide reacted with geminal diesters, β-keto esters, and α-cyano esters in hexamethylphosphoric triamide (HMPA) at 150–160 °C to give alkyl phenyl sulfides and α-phenylthio esters, ketones, and nitriles, respectively, along with evolution of carbon dioxide.
Stereospecific Synthesis of the C-9–C-16 Segment of Carbonolide B, the Aglycon of Carbomycin B
Authors: Tatsuta Kuniaki , Yamauchi Toyoaki , Kinoshita Mitsuhiro
Published: July 2006

Stereospecific synthetic routes to methyl (R)-7-hydroxy-(2E,4E)-octadienoate (9) and its (2E,4Z)-isomer (16), the former which can be a useful chemical precursor to the 16-membered-ring aglycon of carbomycin B (carbonolide B), are discussed. Compound 9, corresponding to its C-9–C-16 segment, was synthesized starting with methyl 2-deoxy-α-d-arabion-hexopyranoside (2). The deoxysugar 2 was converted to the masked 2,4,6-trideoxy-d-threo-hexopyranose (6) via the 4,6-dichloro-2,4,6-trideoxy-α-d-lyxo-hexopyranoside derivative. Treatment of 6 with p-toluenesulfonyl chloride and triethylamine afforded 3-O-acetyl-1,5-anhydro-2,4,6-trideoxy-d-threo-hex-1-enitol, which by reaction with mercury(II) acetate was converted to (R)-5-hydroxy-(2E)-hexenal (8). Reaction of 8 with Wittig reagent gave the (2E,4E)-isomer 9. Compound 16 was prepared by the Wittig reaction with the 2,3-unsaturated deoxysugar, 2,3,4,6-tetradeoxy-d-glycero-hex-2-enopyranose, which was derived from methyl 2,3-anhydro-4,6-dideoxy-α-d-lyxo-hexopyranoside by treatment with potassium selenocyanate followed by acid hydrolysis.
Studies of Reactions of Amines with Sulfur Trioxide. V. Transsulfonation of Amine Salts of Some N-Substituted Amidosulfuric Acids
Authors: Kanetani Fujio , Yamaguchi Hachiro
Published: July 2006

4-Methylanilinium butylamidosulfate, butylammonium (4-methylphenyl)amidosulfate, and 4-methylanilinium (4-methylphenyl)amidosulfate were heated separately under reduced pressure at different temperatures ranging from 80 to 180 °C. Butylammonium butylamidosulfate was heated with 4-methylaniline under atmospheric and reduced pressure. The product compositions were determined as functions of reaction time and temperature, and the components were separated and identified. At lower temperatures (4-methylphenyl)amidosulfate and 4-methylaniline-N,2-disulfonate were the major products, while at higher temperatures 4-methylaniine-2-sulfonate and 2,6-disulfonate were the major products. The ease of N–S bond cleavage of the amidosulfate salts (RNHSO3–R′NH3+) (1) depends largely on the basicity of both the parent amine (R′NH2) (2) and the salt-forming base (R′NH2) (3). The results suggest that the initial step of the transsulfonation involves the dissociation of 1 into 3 and the free acid followed by an equilibration between RNHSO3H and RNH2+SO3− (4). It is considered that 4 may be the sulfonating species and the free amines, 2 and 3, should be the receptors of a sulfonate group. In contrast to the widely accepted scheme (transsulfonation and subsequent intramolecular rearrangement), our results show that both the transsulfonation and the rearrangement process occur concurrently and the same type of mechanism (a bimolecular displacement, viz., B+ : SO3−+B′: \ightleftarrowsB+: +B+: SO3−) may be operative.
Dipole Moments of Molecules Containing Single Chlorine Atoms
Authors: Sugie Masaaki , Takeo Harutoshi , Matsumura Chi
Published: July 2006

The dipole moments of CD2ClF, CHDClF, CH3CHClF, CH3CCl=CH2, and DCOCl have been determined from the J=1←0 transitions of their microwave spectra. For the analyses of the Stark effects, the method of the intermediate field case proposed by Mizushima has been used.
Flux Growth of Double Oxides of Niobium and Rare-earth Elements (Ln3NbO7)
Authors: Yamasaki Yuichi , Sugitani Yoshinori
Published: July 2006

Crystals of double oxides of rare-earth and niobium Ln3NbO7, where Ln=Ho, Y, Er, Dy, and La, and those of rare-earth and tantalum Ln3TaO7, where Ln=Y, Er, and Gd, were grown by Bi2O3-B2O3 and PbF2-PbO fluxes for the Ln3NbO7, and by PbF2-PbO flux for the Ln3TaO7. The composition of Ln3NbO7 or Ln3TaO7 is not yet known in natural minerals.
Solvochromism and Thermochromism of Cobalt(II) Complexes Solubilized in Reversed Micelles
Authors: Sunamoto Junzo , Hamada Tomiko
Published: July 2006

Configurational change takes place between tetrahedral and octahedral species, when cobalt(II) complexes are cosolubilized in reversed micelles formed by the cationic or ampholytic detergents in chloroform. This is accompanied by the elimination-addition reaction of ligand water from and to the metal ion in the reversed micellar core. The phenomenon is interpreted in terms of solvochromism and thermochromism. The nature and state of “naked” metal ion and “free” water molecule afforded in a highly restricted field of reversed micelles have been discussed on the basis of equilibrium constants and thermodynamic parameters for the configurational change, particular attention being given to the structure of micelles. Their resemblance to the active site of metalloenzymes is also discussed.
Binuclear Metal Complexes. XXIV. Synthesis and Magnetism of Binuclear Cobalt(II) Complexes in Mixed-spin State
Authors: Torihara Naoyuki , Okawa Hisashi , Kida Sigeo
Published: July 2006

Binuclear cobalt(II) complexes, Co2(fsaR)(py)3 and Co2(fsaR)MeOH·1/2H2O with 3-formylsalicylic aciddiamine SchifF bases, H4fsaR (R=en, pn, bn, ch, and ph), were prepared and characterized. Mixed-spin states of these complexes were demonstrated by the cryomagnetic measurements and no spin-exchange interaction was observed between high-spin and low-spin cobalt(II) ions. The absence of spin-exchange interaction in these complexes was discussed on the basis of the electronic configuration of the low-spin cobalt(II) ion and in comparison with the antiferromagnetic Cu(II)–Co(II) (s=3⁄2) complexes with the same ligands.
Aromatic Solvent-induced Shifts (ASIS). II. Interpretation of Benzene and Hexafluorobenzene Induced Shifts by Means of the Electrostatic Interaction Model
Authors: Nikki Kunio , Nakagawa Naoya
Published: July 2006

The relationships between the ASIS in proton magnetic resonance and charge distribution in the solute and solvent molecules were studied. The results obtained are as follows. Protons lying in the positive charge-region of the solute dipole showed an up-field shift in C6H6 and a down-field shift in C6F6, while protons lying in the negative charge-region showed a down-field shift in C6H6 and an up-field shift in C6F6. There exists a linear relationship between the ASIS and the solute dipole moments of monosubstituted methanes, t-butyl derivatives, and para substituted toluenes. Shifts of para substituted toluenes and 4-methyl-4′-nitrobiphenyl are in good agreement with those expected from the electrostatic interaction model.
Asymmetric Synthesis Based on (2R,3S)-3,4-Dimethyl-2-phenylperhydro-1,4-oxazepine-5,7-dione. Synthesis of Highly Optically Active β-Substituted Alkanoic Acids
Authors: Mukaiyama Teruaki , Takeda Takeshi , Fujimoto Katsumi
Published: July 2006

A general method was worked out for the preparation of highly optically pure β-substituted alkanoic acids from aldehydes with use of (2R,3S)-6-alkylidene-3,4-dimethyl-2-phenylperhydro-1,4-oxazepine-5,7-diones(2) as key intermediates. Oxazepines(2) were prepared in high yields by treating aldehydes with (2R,3S)-3,4-dimethyl-2-phenylperhydro-1,4-oxazepine-5,7-dione(1) in the presence of titanium tetrachloride. The conjugate addition of Grignard reagents to 2 in the presence of nickel chloride, followed by hydrolysis and decarboxylation afforded highly enantiomerically pure β-substituted alkanoic acids in good yields. The addition of lithium dialkylcuprate to 2 was examined. It was found that (S)-(+)-3-phenylheptanoic acid is obtained by the reaction of lithium dibutylcuprate with (E)- and (Z)-6-benzylidene derivatives of 1, respectively.
The Carbon-13 NMR Spectra of Barbituric-acid Derivatives
Authors: Asada Shozo , Nishijo Jujiro
Published: July 2006

The 13C nuclear magnetic resonance spectra of thirty kinds of barbituric-acid derivatives were measured, and the chemical shifts of each carbon were assigned. The correlation between chemical shifts of the ring skeletal carbon and the pKa values was examined.
Microwave Spectrum, Barrier to Internal Rotation, and Dipole Moment of Methyl Selenocyanate
Authors: Sakaizumi Takeshi , Kohri Yoshio , Ohashi Osamu , Yamaguchi Ichiro
Published: July 2006

Microwave rotational spectra of five isotopic species of methyl selenocyanate (CH3SeCN with 82Se, 80Se, 78Se, 77Se, and 76Se) in the ground vibrational state, and two isotopic species of methyl selenocyanate-d3 (CD3SeCN with 80Se and 78Se) in the ground and first excited states of the methyl torsional mode have been assigned in the 8.0 to 35.5 GHz frequency range. For the most abundant species in the ground vibrational state, the rotational constants determined are AA=10147±2, BA=3483.57±0.04, and C=2631.58±0.04 MHz for CH380SeCN and A=8322.57±0.81, B=3308.06±0.02, and C=2436.92±0.01 MHz for CD380SeCN. The A-E splittings due to the methyl internal rotation were observed for the rotational transitions in the ground vibrational state for the normal species and in the first excited state of the methyl torsional mode for the deuterated species. Analysis of the splittings gave a barrier height to the methyl internal rotation of 1241±50 and 1228±50 cal/mol for the CH3 and CD3 species, respectively. Stark measurements yielded the principal axis dipole moments of μa=4.35±0.04, μb=0.76±0.10, and the total dipole moment of μ=4.42±0.05 D for CH380SeCN, and μa=4.31±0.04, μb=0.67±0.07, and μ=4.36±0.04 D for CD380SeCN. The direction of the dipole moment in the molecule is discussed.
Triplet-Triplet Energy Transfer between Like Molecules
Authors: Inoue Akinori , Chuman Hiroshi , Ebara Nozomu
Published: July 2006

The previously proposed method of studying T-T energy trasfer between like molecules using isotopic mixtures was further improved and applied to an investigation of naphthalene and phenanthrene molecules. Critical transfer distances of 15 and 13 Å were determined for naphthalene and phenanthrene, respectively. The present method has the advantage that it is free from the effect of S-S energy transfer.
NMR Studies on Zerovalent Metal π-Complexes of Dibenzylideneacetone. I. Ligand Conformation and bonding in the Binuclear Palladium Complex
Authors: Kawazura Hiroshi , Tanaka Hisao , Yamada Koh-ichi , Takahashi Toshio , Ishii Yoshio
Published: July 2006

To elucidate the ligand conformation and the metal–olefin bonding nature in the binuclear palladium complex of dibenzylideneacetone, Pd2[(C6H5CH=CH)2CO]3, 1H NMR studies have been performed on the deuteriated complexes Pd2[(C6D5CH=CH)2CO]3, Pd2[(C6D5CD=CH)2CO]3, and Pd2[(C6D5CH=CD)2CO]3. Examination of the spectra has revealed that the three dibenzylideneacetone ligands which triply bridge the two Pd atoms are all in the s-cis,trans conformation. The most probable bonding scheme of the three ligands to the two Pd atoms is as follows: one Pd atom is ligated by one s-trans and two s-cis olefinic moieties and hence the other by one s-cis and two s-trans to yield a metal–olefin bonding stronger in the former combination than in the latter. A linear correlation between the couplings and the mean chemical shifts of the trans olefinic protons suggests a dominant role of metal between the couplings and the mean chemical shifts of the trans olefinic protons suggests a dominant role of metal to olefin π-back donation in differentiating the olefinic moieties in their bonding strength to the metal atoms and in retaining the characteristic rigid structure of the complex.
Resonance Energies of Nonbenzenoid Hydrocarbons
Authors: Aihara Jun-ichi
Published: July 2006

Resonance energies of 30 conjugated hydrocarbons and their molecular ions have been calculated on the basis of the graph-theoretical theory of aromaticity. No difficulty was found in extending the aromaticity theory to ionic conjugated species. In general, the resonance energies obtained correlated well with typical chemical features of the compounds.