bluuebunny/crossref_metadata_2025 huggingface dataset:
X-Ray Photoelectron Spectra of Adsorbed Methyl Acetoacetate and Coordinated Tartaric Acid, Aspartic Acid and Alanine on the Nickel Surface
Authors: Inoue Yasunobu , Okabe Kiyomi , Yasumori Iwao
Published: July 2006

The adsorption of methyl acetoacetate and the coordination of tartaric acid, aspartic acid, and alanine on the nickel surface were studied by means of X-ray photoelectron spectroscopy. The adsorbed methyl acetoacetate was partly in the enol-form, and the amino acids were coordinated with the surface through COO− and NH2 groups in a manner similar to the corresponding nickel chelate complexes, whereas the interaction of OH groups of tartaric acid with the surface was rather weak.
Characterization of Intramolecular Charge-transfer Transitions. 1-Aryl-1,2,2-tricyanoethylenes and 7-Aryl-7,8,8-tricyanoquinodimethanes
Authors: Aihara Jun-ichi , Araya Kotaro , Matsunaga Yoshio
Published: July 2006

For the title compounds, the energy of the first electronic transition is linearly related to the vertical ionization potential of the aromatic nucleus (e.g., benzene in the case of 1-phenyl-1,2,2-tricyanoethylene). This relationship gives a definite experimental support to the chargetransfer character of the electronic transitions concerned.
Equilibria of Aluminium(III) Complexes with 3,3′-Bis[N,N′-bis(carboxymethyl)aminomethyl]-o-cresolsulfonphthalein
Authors: Murakami Sadaaki , Yoshino Takashi
Published: July 2006

A potentiometric and spectrophotometric study of aluminium(III) complexes with 3,3′-bis[N,N′-bis(carboxymethyl)aminomethyl]-o-cresolsulfonphthalein has been performed. Evidence was found for the formations of 1 : 1 and 2 : 1 (metal : ligand) complexes and it was assumed that protonated and hydroxo complexes are formed in addition to the simple complexes. The formation constants for these complexes were determined and suggestions are made concerning the probable structures of the complexes.
Enolate Anions. IV. The 13C NMR Spectra of Sodium Enolates of Ethyl Phenylacetates in DMSO
Authors: Kiyooka Syun-ichi , Suzuki Kojiro
Published: July 2006

The 13C NMR spectra of the sodium enolates of ethyl (p-substituted phenyl)acetates are presented. The polar interactions between the substituents and the anionic moiety in the sodium enolates are estimated by means of their 13C chemical shifts.
The Copyrolysis of 1,2,3-Trichloropropane and Methanol on Activated Alumina
Authors: Shinoda Kiyonori , Yasuda Kensei
Published: July 2006

The copyrolysis of 1,2,3-trichloropropane and methanol gave 1,2-dichloro-3-methoxypropane as well as dichloropropenes and their derivatives. The formation of 1,2-dichloro-3-methoxypropane is also described.
The Reduction of 2-Benzylidene-3(2H)-benzofuranones with Lithium Aluminium Hydride–Aluminium Chloride
Authors: Kurosawa Kazu , Morita Yasuhiro
Published: July 2006

The reduction of various 2-benzylidene-3(2H)-benzofuranones with lithium aluminium hydride-aluminium chloride in ether gave the corresponding 2-benzylbenzofurans in moderate yields. The reduction of 6-methoxy-2-(4-methoxybenzoyl)benzofuran also yielded 6-methoxy-2-(4-methoxybenzyl)benzofuran.
On Behaviors of a New Chemical Reaction Model Showing Hard Oscillations
Authors: Iwamoto Kazutoshi , Seno Manabu
Published: July 2006

The behavior of a new chemical reaction model was studied and the existence of hard oscillations was confirmed. This chemical reaction model is useful because it is easy to apply to investigations of the behavior of a chemically oscillating system surrounded by membranes or in a well-stirred continuous flow reactor. The latter was discussed relating to the chaotic oscillations due to the Belousov-Zhabotinskii reaction in a well-stirred continuous flow reactor reported by Schmitz et al.
Photodissociation Reaction from Higher Excited Triplet States of [2.2]Paracyclophane
Authors: Ishikawa Shun-ichi , Nakamura Junko , Nagakura Saburo
Published: July 2006

The mechanism of photodissociation of [2.2]paracyclophane in glassy solvent at 77 K was studied. It is concluded that the dissociation of the CH2–CH2 bridge occurs from higher triplet states (Tn) via the lowest triplet state as an intermediate. The efficiency of the reaction depends on the characters of Tn states; high from the locally excited state, and low from the charge-transfer state.
Pressure-induced Phase Transition and Compressive Behavior of Substituted Adamantanes
Authors: Hara Kimihiko , Katou Yoshikazu , Osugi Jiro
Published: July 2006

The compressive behavior of adamantane and its secondary monosubstituted derivatives; adamantanone, 2-methyladamantane, and 2-bromoadamantane was measured at various temperatures in a piston-cylinder apparatus. A first-order solid-solid phase transition was found under pressure in each system. The transition pressures, the equilibrium pressures, the volume changes, and the entropy changes for the transition were determined. The compression data for the low pressure phases were fitted to an equation of the form −ΔV⁄V0=a0+a1P+a2P2. The effects of substituent groups on the entropy changes of the transitions of these molecular crystals were discussed.
Nuclear Magnetic Resonance and Circular Dichroism Spectra of 2-(Aminomethyl)cyclohexylamine Platinum(II) Complexes
Authors: Okamoto Koji , Noji Masahide , Kidani Yoshinori
Published: July 2006

Six-membered platinum(II) complexes of 2-(aminomethyl)cyclohexylamine (=amcha), whose four isomers are (1R,2R)-, (1S,2S)-, (1R,2S)-, and (lS,2R)-amcha, were synthesized. The conformations of [Pt(en)(lS,2S-amcha)]Cl2, [Pt(NH3)2(1S,2R-amcha)]Cl2, [Pt(en)(1R,2R-amcha)]Cl2, and [Pt(NH3)2(1R,2R-amcha)]Cl2 were determined by 1H-NMR, 13C-NMR, and CD spectra. It is proposed that [Pt(en)1S,2S-amcha)]Cl2 and [Pt(NH3)2(1S,2S-amcha)]Cl2 take a fixed chair form with a dihedral angle (Pt–N–C(1)–C(6)) of 180°, while [Pt(en)(1S,2S-amcha)]Cl2 and [Pt(NH3)2(1S,2S-amcha)]Cl2 are interconverting between two chair forms.
A Kinetic Study of the Base Hydrolysis of (2-Aminoethanol)bis-(ethylenediamine)halogenocobalt(III) Complexes
Authors: Ogino Kazuko , Seki Hitoshi
Published: July 2006

The base hydrolysis of cis-[CoX(etaH)(en)2]2+(X=Cl or Br, etaH=2-aminoethanol, en=ethylenediamine) has been studied. The hydrolysis results in the formation of [Co(eta)(en)2]2+ (≈35%) and [Co(OH)(etaH)(en)2]2+ (≈65%) at I=1.0 (KNO3), 25 °C, the product ratio being independent of the pH. The base hydrolysis has also been studied in the presence of sodium azide.
Chiral Mesophases of 12-Hydroxyoctadecanoic Acid in Jelly and in the Solid State. II. A New Type of Mesomorphic Solid State
Authors: Tachibana Taro , Mori Tomoko , Hori Kayako
Published: July 2006

A new type of chiral solid mesophase was obtained by evaporating the solvents from solutions or jellies of chiral 12-hydroxyoctadecanoic acid (12HOA). The mesomorphic solids exhibited some optical properties characteristic of a helicoidal mesophase: (1) spherulitic or Schlieren texture under a polarizing microscope, (2) reflective circular dichroic band, and (3) induced circular dichroic spectra with a single sign due to achiral molecules added to the solid. From the circular dichroic and X-ray studies, it was concluded that the helicoidal mesophase structure exists locally as small domains with a chiral smectic structure within the mesomorphic solids. Microscopic observation revealed that, upon heating, the transition of the mesomorphic solid to the crystalline solid occurred. This process was studied by differential scanning calorimetry. Formation of a variety of helicoidal systems from chiral molecules such as 12HOA and polypeptides was regarded as a phenomenon characteristic of chiral assemblies of amphiphilic molecules.
Kinetics of the Catalytic Decomposition of Hydrogen Iodide in the Magnesium–Iodine Thermochemical Cycle
Authors: Oosawa Yoshinao , Kumagai Toshiya , Mizuta Susumu , Kondo Wakichi , Takemori Yoshio , Fujii Kinjiro
Published: July 2006

The decomposition of hydrogen iodide serves as the hydrogen-evolution step in several thermochemical water-splitting cycles, including the Magnesium–Iodine cycle. A kinetic analysis of the catalytic decomposition of hydrogen iodide has been carried out by the use of a flow method at 500–700 K. The platinum-supported active carbon catalyst (1 wt%) and the active carbon catalyst which have been found effective in the research reported previously, are used as the catalysts. The contact time-conversion relationships for both the catalysts are simulated successfully on the basis of an assumed reaction scheme. The influence of water vapor on the rate and the equilibrium of the decomposition of hydrogen iodide is negligibly small. The inhibition effect of iodine on the rate of the decomposition of hydrogen iodide over the platinum-supported active carbon catalyst is remarkable below 550 K.
Phase Relations in the System PbO–PbSiO3
Authors: Hirota Kazushi , Hasegawa Yasutoshi T
Published: July 2006

Phase relations in the system PbO–PbSiO3 were determined at temperatures above 650 °C. Two new lead silicate phases, Pb5SiO7 and Pb11Si3O17 were found to be stable. The former melts incongruently at 733±1 °C to solid PbO plus liquid, and decomposes below 702±1 °C. The latter melts congruently at 728±1 °C. The compound Pb4SiO6, which has been accepted as stable, could not be confirmed.
The Crystal and Molecular Structure of [trans-1,2-Bis(diphenyl-phosphinamino)cyclohexane](1,5-cyclooctadiene)rhodium(I) Perchlorate Dichloromethane Solvate
Authors: Onuma Ken-ichi , Nakamura Asao
Published: July 2006

The molecular structure of the title compound has been determined from three-dimensional X-ray diffraction data. The crystal belongs to the triclinic system: P\bar1, a=11.488(2), b=18.163(2), c=10.998(2)Å, α=101.70(2), β=118.29(1), γ=85.32(3)°, Z=2. The structure has been refined by block-diagonal least-squares techniques using 3749 non-zero reflections to the final R value of 0.067. The rhodium atom is coordinated in a slightly distorted square-planar geometry by the bisphosphine and the diene ligand, with average Rh–P and Rh–C distances of 2.301(2) and 2.26(1)Å, respectively. The seven-membered chelate ring takes a distorted boat conformation, and the two phenyl groups of diphenylphosphine are arranged in a face-edge manner and those of the other diphenylphosphine are in a helical arrangement like a propeller, viewed from cycloocta diene.
Nonbenzenoid Aromatic Compounds Containing an anti-Aromatic Four-membered Ring. Synthesis and Some Properties of 7-Hydroxy-6H-benzo[3,4]cyclobuta[1,2]cyclohepten-6-one (Benzo[3,4]cyclobuta[1,2-e]tropolone)
Authors: Sato Masaru , Ebine Seiji , Nishijima Kazumi , Tsunetsugu Josuke
Published: July 2006

Biphenylene-2,3-quinone reacts with diazomethane in the presence of boron trifluoride etherate to give 7-hydroxy-6H-benzo[3,4]cyclobuta[1,2]cyclohepten-6-one (5) and its boron difluoride chelate. The latter is convertible quantitatively into the former. Compound 5 has a reduced troponoid character due to fusion of the benzocyclobutadiene ring. Tautomerism of the tropolone ring in 5 seems to be imposed exclusively to one of the tautomers. Protonation of 5 gives a tropylium ion whose positive charge is partially localized. Bromination, nitration, and azo-coupling of 5 give only 7-substituted products. The reaction of 5 with maleic anhydride gives the Diels-Alder adduct in good yield.
Products from the Nitration of 2,5-Dimethylthiophene and Its 3,4-Dibromo Derivative. Two Modes of the Formation of Dithienylmethanes
Authors: Suzuki Hitomi , Hidaka Ichiro , Iwasa Akemi , Mishina Tadashi , Osuka Atsuhiro
Published: July 2006

The reaction of 2,5-dimethylthiophene with copper(II) nitrate in acetic anhydride gave 3-nitro-2,5-dimethyl-thiophene and 2,5-dimethyl-3-(5-methyl-2-thenyl)thiophene as major isolable products. The treatment of 3,4-dibromo-2,5-dimethylthiophene with nitric acid (d=1.5) in dichloromethane in the presence of a catalytic amount of sulfuric acid afforded 3,4-dibromo-5-methyl-2-(nitrooxymethyl)thiophene, which, on thin-layer chromatog-raphy over silica gel using hexane as the eluant, underwent a partial novel coupling reaction through the loss of one methylene carbon atom, thus giving 3,3′,4,4′-tetrabromo-5,5′-dimethyldi-2-thienylmethane along with the expected 3,4-dibromo-2-hydroxymethyl-5-methylthiophene and bis(3,4-dibromo-5-methyl-2-thenyl) ether.
Silylation of Relatively Acidic Compounds with Alkyl Trimethylsilylacetates
Authors: Nakamura Eiichi , Hashimoto Koichi , Kuwajima Isao
Published: July 2006

Silylation of ketones, alcohols, alkanethiols, phenols, and carboxylic acids with alkyl trimethylsilylacetates has been described from synthetic and mechanistic points of view.
The Electronic Structures of Condensed Materials Studied by Ultraviolet Photoelectron Spectroscopy
Authors: Takahashi Takashi , Harada Yoshiya
Published: July 2006

The so lid phase ultraviolet photoelectron spectra of water, carbon disulfide, benzene, N-methylaniline, and pentane condensed on a gold substrate at 77 K were measured. The features of the spectra are similar to those of the corresponding gas phase spectra. The difference between the gas and solid phase IP’s, the relaxation shift, is nearly constant for each compound studied except for the case of water, where the 3a1 molecular orbital state in solid is affected by the hydrogen bonding. The values of the relaxation shift for water, benzene and carbon disulfide are 1.1–1.3eV, while those for N-methylaniline and pentane are 0.6 and 0.7 eV, respectively. The small values for the latter compounds are due to the fact that the molecules are loosely packed in the solids. The mechanisms of the band broadening for the molecular crystal are discussed in relation to the spectrum of solid carbon disulfide. For N-methylaniline the spectra of the gas, liquid and solid phases were compared. To our knowledge, this is the first case in which the electronic structures of all the three phases are studied by ultraviolet photoelectron spectroscopy.
Halogenation with N-Halo-2-oxazolidinones. The Chain-carrying N-Centered Radicals
Authors: Migita Toshihiko , Nakayama Mitsumasa , Watanuki Toshiro , Suzuki Mikio , Kosugi Masanori
Published: July 2006

Selectivities in halogenation of 2,3-dimethylbutane, 1-chlorobutane and substituted toluenes with N-chloro-or N-bromo derivatives of 4,4-dimethyl-2-oxazolidinone (NXDMO), 2-oxazolidinone (NXO), and succinimide (NXS) were examined. In the presence of olefin, halogenation of the substituted butane by these N-halo reagents were found to proceed involving hydrogen abstraction by the N-centered radicals, since chlorination by the N-chloro reagents and bromination by the corresponding N-bromo reagents showed the same selectivities. The relative reactivity of a t-C-H bond compared with a prim-C-H bond RSpt markedly depends on the structure of the N-radical, being 200, 70, and 11 at 80 °C toward the radicals derived from NXDMO, NXO, and NXS, respectively. Reaction constant ρ of hydrogen abstraction from the toluenes by the N-radical from NXDMO was −1.0 at 130 °C.
The σ-Bonded Palladium(II) Complex of [π-(Dimethylaminomethyl)-cyclopentadienyl]tetraphenylcyclobutadienecobalt(I)
Authors: Izumi Taeko , Maemura Mitsugi , Endoh Kazuyoshi , Oikawa Tadashi , Zakozi Satoshi , Kasahara Akira
Published: July 2006

[π-(Dimethylaminomethyl)cyclopentadienyl]tetraphenylcyclobutadienecobalt(I) reacts with lithium tetrachloropalladate(II) in the presence of sodium acetate to give an ortho-palladated binuclear complex. The σ-bonded structure of the complex was confirmed by studies of the IR and 1H-NMR spectra and of the reactions with triphenylphosphine, thallium(I) acetylacetonate, and lithium aluminum deuteride. The reactions of the σ-bonded complex with carbon monoxide and olefins have been examined.
“Naked” Hydrogencarbonate Ion as a Bifunctional Catalyst toward Amide Substrates. Nucleophilic Ion Pairs. 9
Authors: Shinkai Seiji , Nakashima Naotoshi , Kunitake Toyoki
Published: July 2006

The cleavage of amide substrates (p-nitro-N-methyltrifiuoroacetanilide and p-nitro-N-methyldichloroacetanilide) with anionic nucleophiles was studied at 30 °C in aprotic (acetonitrile and N,N-dimethylformamide) and protic(ethanol) media. Hydrogencarbonate ion acted as catalyst much more efficiently in the aprotic solvents (about 103 fold) than expected from its aqueous pKa, but in ethanol, its reactivity was close to those of simple nucleophiles (p-cyanophenolate anion and N-hydroxysuccinimide anion) that possess analogous pKa values in water. The reaction rate in the aprotic solvents was sensitive to small amounts of water. The kinetic isotope effect showed that proton transfer was involved (at least partially) in the rate-determining step. Thus, hydrogencarbonate ion behaves in aprotic media as a nucleophilic-general acid catalyst for the amide cleavage. The biochemical implication with regard to the action of biotin was discussed.
Study of Phase Transfer Catalysis by Layered Scintillation Method
Authors: Hideshima Taketoshi , Morinaga Misao , Kimizuka Hideo
Published: July 2006

The static and kinetic feature of the reaction of sodium cyanide with 1-bromoalkanes in the presence of various phase transfer catalysts was investigated in the oil/water system by using a layered scintillation method and the mechanism of catalytic action was discussed. From the measurement of equilibrium constants for both reactions of hexadecyltrimethylammonium cyanide with 1-bromooctane and of sodium cyanide with hexadecyltrimethylammonium bromide in organic phase, it was pointed out that the latter reaction was responsible for the advance of overall reaction. It was also found that majority of the phase transfer catalysts exist in the oil phase. It was suggested that an uptake reaction of cyanide ion from the aqueous phase at the interface is essential and that the reaction process does not follow a simple model proposed by Starks et al.
The Crystal and Molecular Structures of Paracyclophadiynes
Authors: Ueda Hideo , Katayama Chuji , Tanaka Jiro
Published: July 2006

The molecular structures of tetramethyl[3.3]paracyclophadine(I) and [3.4]paracyclophadiyne(II) have been determined by X-ray analysis. Both crystals are monoclinic, with the space group of P21/c. The crystal data are: a=9.170(4), b=9.208(3), c=18.232(7) Å, β=94.0(1)°, Z=4 for (I) and a=10.938(3), b=9.173(2), c=14.988(4) Å, β=116.1(1)°, Z=4 for (II). In both molecules, consisting of benzene and diacetylene groups linked by two methylene-bridges, the diacetylene chain is bent into a bow shape. The (I) molecule has Cs symmetry, and the distances (3.019–3.256 Å) between the atoms of the diacetylene group and the benzene plane are smaller than those of [3.3]paracyclophadiyne(Aono, Sakabe, Sakabe, Katayama, and Tanaka, 1975). The methylene-bridge of [3.4]paracyclophadiyne has a disordered structure.
A Method of Estimating the Diffusion Coefficient of Disperse Dyes into Hydrophobic Fibers from the Initial Sorption Data of Dyeing by Means of the Polynomial Least-squares Method
Authors: Shibusawa Takao
Published: July 2006

For the initial and the medium stage of diffusion, Hill’s equation was approximated by the simple polynomial in the form of Mt⁄M∞≈P1(Dt⁄r2)1⁄2–P2(Dt⁄r2) where P1 and P2 are constants depending on the interval in which the approximation is used, while the other symbols have a usual meanings. On the other hand, several experimental Mt’s were plotted against square root of t, and an experimental formula describing the regression curve passing through a discrete set of experimental points, Mt=A0+A1t1⁄2–A2t, was obtained by means of curve fitting with a polynomial of degree 2. From the polynomial approximation and the experimental formula, the following equations which are capable of calculating the approximate value of M∞ and D were obtained.

(D⁄r2)1⁄2≈(A2P1)⁄(A1P2), M∞≈(A12P12)⁄(A2P12)

Then the method for obtaining more probable values of D and M∞ was described, in this method the approximations to inverse function of Hill’s equation and the curve fitting with polynomial of degree 2 were used.
A Molecular Orbital Study of the Conformation and g-Factors of the H2SSH2+ and H2SSH Radicals
Authors: Kikuchi Osamu
Published: July 2006

The conformation and g-factors of the H2SSH2+ and H2SSH radicals were analyzed by means of a restricted open-shell SCF MO method with the semiempirical MINDO/3 and INDO approximations, and the observed g-factors of the family of radicals consisting of R2SSR2+, R2SSR, and RSSR− were compared on the basis of their molecular and electronic structures.
Charge-transfer Interaction and Ground-state Energy Stabilization in Crystalline Complex Ion Radical Salts
Authors: Iida Yôichi
Published: July 2006

Although predominant cohesive energy is Madelung energy, the ground state of crystalline complex ion radical salt is further stabilized by the charge-transfer interaction between neutral molecule and ion radical, together with that between ion radicals. The magnitude of this stabilization energy was estimated with (Phenothiazine)2+· Br−.
The Core-level Binding Energies and the Structures of Nickel Complexes
Authors: Yoshida Tooru , Yamasaki Kiyoshi
Published: July 2006

The X-ray photoelectron spectra of thirty two nickel complexes were measured in order to examine the relation between the structures and the core-level binding energies of the complexes. The differences between the energies of Ni(2p) and Ni(3p) electrons for the complexes with an octahedral structure were about 1 eV larger than for those with a square planar one.
Synthesis and Absorption Spectra of Annelated 5-Amino-1,4-diazaanthraquinones and Related Compounds
Authors: Nakazumi Hiroyuki , Kondo Kazuyoshi , Kitao Teijiro
Published: July 2006

New annelated 5-amino 1,4-diazaanthraquinones and related derivatives were prepared from 2,3,5-triamino-1,4-naphthoquinone or 5-amino-2,3-dichloro-1,4-naphthoquinone. Their visible absorption spectra were examined by the PPP-SCF-MO calculation with a variable β approximation.
Phenalenones. III. The Anomalous Diazotization of 3-Substituted 2-Aminophenalenones
Authors: Kuroki Masatane , Tsunashima Yutaka
Published: July 2006

The diazotization of 3-substituted 2-amino-1H-phenalen-1-ones (substituents=Cl, Br, PhS, or OH) gave 2-diazo-1H-phenalene-1,3(2H)-dione. It is most probable that the reaction involves the intramolecular rearrangement of a transient diazohydroxide intermediate and the consequent elimination of the substituent at the 3-position.
Study of Cationic Surfactant Ion Selective Poly(vinyl chloride) Membrane Electrode Containing Dibenzo-18-crown-6
Authors: Maeda Tamaki , Ikeda Makoto , Shibahara Mitsuhiro , Haruta Takahide , Satake Iwao
Published: July 2006

Study was made of the potentiometric selectivities of poly(vinyl chloride) membrane with and without dibenzo-18-crown-6. It was found that these membrane electrodes were highly selective for cationic surfactant ions and showed a Nernstian response to surfactant ion such as 1-dodecylpyridinium ion even in the concentration range as low as 10−6 mol/dm3. The selectivity coefficients of inorganic cations, taken with respect to 1-dodecylpyridinium ion, were of the order of 10−5 or less, while that of surfactant ion was found to depend not only on hydrophobic alkyl chain length but also on the type of hydrophilic head group. For cationic surfactants with the same hydrocarbon chain length, the membrane without crown ether exhibited the order of selectivity: 1-alkylpyridinium ion>alkyltrimethylammonium ion>alkylammonium ion. In the case of the membrane with crown ether, the selectivity sequence became alkylammonium ion>1-alkylpy ridinium ion>alkyl trimethylammonium ion. For a homologous series of cationic surfactants, the selectivity coefficient increased regularly with increasing alkyl chain length.
The Crystal Structures of Hexamethyleneiminium p-Chlorobenzoate and Dimorphs of Hexamethyleneiminium p-Bromobenzoate
Authors: Kashino Setsuo , Sasahara Norimitsu , Kataoka Shin-ichi , Haisa Masao
Published: July 2006

The crystal structures of hexamethyleneiminium p-chlorobenzoate (1), and the monoclinic [2(m)] and orthorhombic [2(o)] forms of hexamethyleneiminium p-bromobenzoate have been determined from visually estimated Cu Kα data. The crystal data are: P21c, a=10.10(2), b=16.78(1), c=9.01(2) Å, β=118.4(2)°, Z=4 for 1; C2/c, a=25.47(2), b=7.01(1), c=16.29(1) Å, β=109.1(1)°, Z=8 for 2(m); and Pbca, a=11.55(1), b=27.40(1), c=8.57(1) Å, Z=8 for 2(o). The structures of 1, 2(m), and 2(o) were refined to R values of 0.072, 0.100, and 0.083 for 1628, 1009, and 1013 non-zero reflections, respectively. In the crystals of 1, the type of hydrogen bond and the molecular arrangement in (010) plane are the same as those in piperazinediylium terephthalate. In 2(m), two pairs of the base and acid ions related by a twofold axis are linked together by N–H···O hydrogen bonds. The crystal structure of 2(o) is very similar to that of piperidinium and pyrrolidinium p-substituted benzoates in Pbca, but there is a difference in the combination mode of the base and acid ions participating in the hydrogen bonds. In all the crystals, the hydrogen bond extending along the long axis of the acid ion is shorter than that nearly perpendicular to the axis. Hexamethyleneimine rings in 1, 2(m), and 2(o) take a similar twist-chair conformation.
Studies on Chemiluminescent Compounds. I. Syntheses of Acylsubstituted Anthracene Derivatives and Their Chemiluminescence
Authors: Hiramatsu Toshiyuki , Harada Toshiaki , Yamaji Teizo
Published: July 2006

New anthracene derivatives with a –COCH– group, such as 1,5-dipropionylanthracene, 1,8-dipropionylanthracene, 1,5-di-isobutyrylanthracene, 1,8-diisobutyrylanthracene, 1,5-bis[3-(methoxycarbonyl)propionyl]anthracene, 1,8-bis[3-(methoxycarbonyl)propionyl] anthracene, 1,5-bis(cyclohexylcarbonyl) anthracene, 3,7-diisopropyl-1,5-diisobutyrylanthracene, and 5-dimethylamino-4-isobutyryl-1-methoxyanthracene (10) have been synthesized. Their direct chemiluminescences were studied by air oxidation in alkaline solutions. The properties of the chemiluminescence have been found to be influenced by not only the class of the C–H bond adjacent to the carbonyl group but also by the electronic properties of the aromatic ring system, the solvent, and the additive. 10 exhibited the longest chemiluminescence. This chemiluminescent phenomenon might be explained by a chemically initiated electron exchange luminescence (CIEEL) mechanism.
Crystal and Molecular Structures of Octaethylporphinium(monocation) Triiodide and Its Benzene Hemisolvate
Authors: Hirayama Noriaki , Takenaka Akio , Sasada Yoshio , Watanabe Ei-ichi , Ogoshi Hisanobu , Yoshida Zen-ichi
Published: July 2006

The structure of the triclinic form of octaethylporphinium (monocation) triiodide was determined by X-ray analysis. The structure of the previously determined orthorhombic form was refined using diffractometer data. The final R values for the triclinic and the orthorhombic forms were 0.060 and 0.069, respectively. The present analysis has established the inherent structure of porphyrin monocations; three pyrrole rings are coplanar and the plane of the fourth ring is tilted from the mean plane of the other three. The magnitude of the tilt angle is 12.5° for the triclinic form and 16.1° for the orthorhombic form.
Proton-transfer Reactions of 5-(m- and p-Nitrophenylazo)salicylic Acids Coupled with Inclusion Reactions with α- and β-Cyclodextrins
Authors: Yoshida Noboru , Fujimoto Masatoshi
Published: July 2006

The title azo compounds, 5-(m- and p-nitrophenylazo)salicylic acids (m- and p-NPAS), were found kinetically to be included into a cavity of α- or β-cyclodextrin. The rate constants for the inclusion reactions were found to be in the order of magnitude 107 and 106 mol−1 dm3 s−1 for α-cyclodextrin and β-cyclodextrin systems, respectively. The 1H and 13C NMR data showed that the hydrophobic nitrobenzene ring moiety of m- and p-NPAS is situated in the α- and the β-cyclodextrin cavity. The proton-transfer reactions of m- and p-NPAS were accelerated in the presence of α- and β-cyclodextrins. This indicates the possibility that the inclusion force of cyclodextrins contributes to weakening the intramolecular hydrogen bond of m- and p-NPAS.
Multidentate Ligand Kinetics. III. The Ligand-substitution Reaction between the Ethylenediaminetetraacetatocuprate(II) Ion and the Tetraethylenepentaminezinc(II) Ion
Authors: Katsuyama Tetsuo , Kumai Toshihiko
Published: July 2006

The kinetics and mechanism of the ligand-substitution reaction between the ethylenediaminetraacetatocuprate(II) ion (Cu(II)-edta) and the tetraethylenepentaminezinc(II) ion (Zn(II)-tetren) were studied spectrophotometrically over the pH range from 7.0 to 9.0 at I=0.2 M (1 M= mol dm−3) and 25.0 °C. The substitution reaction was shown to proceed by means of a chain-reaction mechanism where the chain-propagating steps are the reaction of Cu(II)-edta with tetren and the reaction of Zn(II)-tetren with edta. Each chain-propagating step was investigated. The ligand-substitution reaction of Zn(II)-tetren with edta was studied by the use of the chain reaction. The rate law is expressed as

−\fracd[Zn(II)-tetren]dt=kL[Zn(tetren)2+][edta4−]+kHL[Zn(tetren)2+][Hedta3−]+k′HL[Zn(Htetren)3+][Hedta3−].

The rate constants, kL,kHL, and k′HL were determined at 25.0 °C and I=0.2 M as: kL≈3×102 M−1 s−1, kHL=(4.1±0.7)×102 M−1 s−1, and k′HL=(1.7±0.2)×105 M−1 s−1.
Studies of the Separation Mechanism in Ion-exchange Chromatography. III. Elution Order of cis-Bis(ethylenediamine)cobalt(III) and cis-α-Triethylenetetraminecobalt(III) Complexes on SP-Sephadex C-25 and IEX 510 Resins
Authors: Yoneda Hayami , Wakida Shin-Ichi , Nakazawa Hiroshi , Sakaguchi Ushio
Published: July 2006

Chromatographic separation of cis-dianionobis(ethylenediamine)cobalt(III) and cis-α-dianionotriethylenetetraminecobalt(III) complexes has been investigated by using SP-Sephadex C-25 and IEX 510 cation-exchange resins. The elution order of the complex cations on both resins are rather similar to each other and the adjusted retention volumes of these complexes correlate very closely with the crystallographic volumes (the unit cell volumes divided by the number of molecules in a unit cell) of [Co(X)(NH3)5]Cl2, where X=CN−, Cl−, NO2−, N3−, and NCS−. This has been taken to indicate that the affinity of the complex cation to the functional group of the resins increases as the size of the cation, and hence the character of water-structure breaker of the cation, increases. Thus, the elution order obtained seems to be determined primarily by the difference in the affinities of the complex cations to the resins, rather than by the difference in the association constants for the ion-pairs formed between the complex cation and the eluent anion.
Synthesis of 1,1′-, 2,2′-, 1,2′-, and 2,6′-Biazulenes and Their Derivatives by Ullmann Reaction
Authors: Morita Tadayoshi , Takase Kahei
Published: July 2006

Four kinds of biazulenes, 1,1′- (1a), 2,2′- (2a), 1,2′- (3a), and 2,6′-biazulenes (4a), and their derivatives were synthesized by utilizing Ullmann-type coupling of haloazulene derivatives. Ullmann reaction of ethyl 3-iodo-(5a) and 2-iodoazulene-1-carboxylates (6b) gave diethyl 1,1′-biazulene-3,3′-dicarboxylate (1b) and diethyl 2,2′-biazulene-1,1′-dicarboxylate (2b), respectively, in excellent yields. The reaction of 2-iodoazulene gave 2a directly. Diethyl 2-chloroazulene-1,3-dicarboxy late (7a) and its 5-alkyl derivatives also reacted to give tetraethyl 2,2′-biazulene-1,1′,3,3′-tetracarboxylate (2d) and its 5,5′-dialkyl derivatives, respectively. A mixed Ullmann reaction of 5a and 6b afforded a mixture of 1b, 2b, and diethyl 1,2′-biazulene-1′,3-dicarboxylate (3b). Similarly, a mixed Ullmann reaction of 7a and diethyl 6-iodoazulene-1,3-dicarboxylate gave a mixture of 2d and tetraethyl 2,6′-biazulene-1,1′,3,3′-tetracarboxylate (4b). The parent hydrocarbons of biazulenes, 1a, 2a, 3a, and 4a, could be derived from the corresponding ethoxycarbonyl derivatives, 1b, 2b, 2d, 3b, and 4b, respectively, by decarboxylation. The planarity of biazulenes and their ester derivatives is also discussed on the basis of the spectral data.
The Preparation of Cyclic Dithia and Thiaza Compounds by the Reaction of Potassium Carbonate with Heterocumulenes and Alkylene Dibromides or Carbonate Catalyzed by Organostannyl Compounds
Authors: Fujinami Tatsuo , Sato Shinichi , Uchida Norimasa , Sakai Shizuyoshi
Published: July 2006

Cyclic 1,3-dithia- and 1,3-thiaza-2-ylidene compounds were obtained by the heterogeneous reaction of solid potassium carbonate, a sulfur-containing heterocumulene, such as aryl isothiocyanate, carbon disulfide, or carbonyl sulfide, and alkylene dibromides or ethylene carbonate in the presence of bis(tributylstannyl) compounds. The effect of an organostannyl catalyst on these reactions is discussed.
Synthesis of β- and α-Rotunols. Revision of the Structure of a Stress Metabolite “1-Keto-α-cyperone”
Authors: Murai Akio , Ono Mitsunori , Abiko Atsushi , Masamune Tadashi
Published: July 2006

The synthesis of β- and α-rotunols, two sesquiterpene alcohols isolated from nutgrass (Cyperus rotundus Linne), is described. This synthetic study also involves revision of the structure of a stress metabolite “1-keto-α-cyperone” isolated from Burley and flue-cured tobaccos (Nicotiana tabacum L.).
Reaction of 1-Lithio-1-arylthio(or alkylthio)methyltrimethylsilane with Acid Derivatives. A Novel Synthesis of Functionalized Vinyl Sulfides
Authors: Agawa Toshio , Ishikawa Minori , Komatsu Mitsuo , Ohshiro Yoshiki
Published: July 2006

Reactions of 1-lithio-1-phenylthiomethyl- (1a) and 1-lithio-1-methylthiomethyltrimethylsilane (1b) with amides, an ester, acid anhydrides, a urea, and a carbonate are described which provide useful routes to functionalized vinyl sulfides. The reaction of 1 with amides gave β-functionalized vinyl sulfides, 1-dialkylamino-2-phenylthio (or methylthio)ethylenes, in 40–95% yields and the reaction could be extended to the sulfonyl derivatives of 1 to afford 1-dialkylamino-2-phenylsulfonyl(or methylsulfonyl)ethylenes. Although ethyl benzoate and some acid anhydrides were not good substrates for this reaction, tetramethylurea and diethyl carbonate gave α-functionalized vinyl sulfides, 1-amidovinyl- and 1-(ethoxycarbonyl)vinyl sulfides, in moderate yields when treated with 1a followed by addition of benzaldehyde.
Formation of Electronically Excited Fragments (H, CH, NH) by the Electron Impact of Pyrrole and Pyrrolidine
Authors: Tokue Ikuo , Ikarashi Masami , Ito Yoshio
Published: July 2006

In the wavelength region of 200–600 nm, photoemissions from electronically excited fragments (H, CH, NH, CN, and C2) were observed when pyrrole and pyrrolidine were excited by electron impact (0–70 eV). Hydrogen atoms and CH and NH radicals from pyrrole and pyrrolidine are produced via a single collision excitation. The appearance potentials for these fragments from pyrrole are 19.4±0.8 eV for the hydrogen Balmer β (Hβ), 19.7±0.8 eV for the CH(A2Δ-X2Π) band, and 20.0±1.0 eV for the NH(A3Π-X3Σ) band. Those from pyrrolidine are 18.7±0.8 eV for Hβ, 23.0±0.8 eV for the CH(A-X) band, and 21.8±1.0 eV for the NH(A-X) band. Dissociation processes forming these electronically excited fragments are discussed.
The Aggregation of a Merocyanine Dye in Solution and Film
Authors: Mizutani Fumio , Iijima Sei-ichiro , Tsuda Keishiro
Published: July 2006

Two low-energy bands, one near 595 nm and the other near 630 nm, were observed in the visible absorption spectra of a merocyanine dye (3-carboxymethyl-5-[2-(3-octadecyl-2-benzothiazolinylidene)ethylidene]-2-thioxo-4-thiazolidinone) dissolved in methanol–water mixtures containing KOH and Triton X-100. From the dye-concentration dependence on the spectra, the band near 595 nm was assigned to the tetramer, and the one near 630 nm, (probably) to the hexamer of the carboxylate form of the dye. The same bands were observed in the dye films when they were soaked in aqueous solutions of pH≥5.5. The relative intensities of the two bands were strongly affected by the ionic strength of the aqueous solution.
The Reduction of Cobalt(III) Complexes by Ascorbic Acid. II. The Kinetics and Mechanisms of the Reactions of Diaqua and Aquahydroxo Macrocyclic N4 Complexes
Authors: Tsukahara Keiichi , Izumitani Tatsuo , Yamamoto Yasuo
Published: July 2006

The kinetics of the reductions of several macrocyclic N4 cobalt(III) complexes by l-ascorbic acid (H2A, have been studied at 25.0 °C, at an ionic strength of 0.10 mol dm−3 (LiClO4), and over the pH range from 1.64 to 3.47. The second-order rate constants in dm3 mol−1 s−1 are 3.4±0.6 (Me6[14]4,11-dieneN4), (4.2±0.2)×10 (Me4[14]tetraeneN4), and (4.2±0.1)×10 (ms-Me6[14]aneN4) for the reactions of [Co(N4)(H2O)2]3+ with HA− ions and (1.1±0.1)×102 (Me6[14]4,11-dieneN4), (1.3±0.1)×103 (Me4[14]tetraeneN4), (5.5±0.1)×10 (ms-Me6[14]aneN4), and (2.9±0.6)×10 ([14]aneN4) for the reactions of [Co(OH)(N4)(H2O)]2+ with HA− ions. The mechanisms of these reactions are discussed, and it is concluded that the lack of saturation of macrocyclic ligands facilitates the electron-transfer reaction between cobalt(III) and ascorbic acid.
Mechanism of Copper Transport through a Diaphragm-type Liquid Membrane
Authors: Kataoka Takeshi , Nishiki Tadaaki , Ueyama Koretsune
Published: July 2006

The permeation mechanism of copper with a liquid membrane process was studied by measuring the permeation rate of copper, which was allowed to permeate through a diaphragm-type liquid membrane with LIX64N as a mobile carrier at various concentrations of carrier and acid. The permeation rate is explained approximately by the diffusional process in the membrane for a chelating complex between copper and carrier and by the succeeding stripping reaction at the interface between the membrane and stripping phase.
Photodimerization of Indeno[2,1-a]indene
Authors: Shim Sang Chul , Chae Jeong Seok
Published: July 2006

Indeno[2,1-a]indene, a trans-stilbene analogue with fixed planar configuration, yielded a head-to-head and a head-to-tail C4-cyclodimer on direct irradiation with 300 nm UV light. The fluorescence quenching and sensitization studies indicated the reaction to proceed through excited singlet state, very likely through the singlet excimer intermediate.
Spectral Changes in X-Ray K Emission Lines of Potassium in Various Compounds
Authors: Yasuda Seiji , Kakiyama Hitoo
Published: July 2006

The chemical shifts and profile changes in the Kα1,2, Kβ1,3 and their satellite lines of potassium from 21 chemical compounds were measured with a two-crystal X-ray spectrometer. The data obtained are discussed qualitatively and related to the nature of the surrounding groups.
A New Efficient and Stereoselective Synthesis of Ubiquinone-10
Authors: Fujita Yoshiji , Ishiguro Michihiro , Onishi Takashi , Nishida Takashi
Published: July 2006

Coupling reaction of 6-cupro-2,3-dimethoxy-5-methylhydroquinone bis(2-methoxyethoxymethyl) ether with (2E)-1-(phenylsulfonyl)-2-methyl-4-chloro-2-butene afforded the sulfone-functionalized prenylhydro quinone (6) in 82% yield. Stereoselective synthesis of ubiquinone-10 was achieved by the condensation of 6 and solanesyl bromide (yield 92%), reductive elimination of the sulfone group by sodium–ethyl alcohol in THF (yield 80%), and followed by air oxidation of the hydroquinone.
Reduction of α,β-Unsaturated Carbonyl Compounds to the Saturated Alcohols Using Hydridocarbonyliron Complexes
Authors: Yamashita Masakazu , Miyoshi Kanako , Okada Yasuhiro , Suemitsu Rikisaku
Published: July 2006

Tetracarbonylhydridoferrate was found to be effective for the selective reduction of α,β-unsaturated carbonyl compounds to the corresponding saturated alcohols. The reactions proceeded stereospecifically and (−)- and (+)-neodihydrocarveol were obtained exclusively from (+)- and (−)-carvone respectively. The reaction mechanism is briefly discussed.
Pressure Effect on Reaction Rate of Cycloaddition of Tetracyanoethylene with α-Methylstyrene in Some Aprotic Solvents
Authors: Tsuzuki Hideaki , Uosaki Yasuhiro , Nakahara Masaru , Sasaki Muneo , Osugi Jiro
Published: July 2006

The high-pressure kinetic study of the title reaction was carried out at 25 °C up to 1500 bar in carbon tetrachloride, chloroform, 1,2-dichloroethane, and acetonitrile, taking into account the role of the EDA complex formation. The dipole moment at the transition state is as large as 8.5±0.5 debye by Kirkwood’s electrostatic model. The solvent effect is also ascribable to the polarity change upon activation. The intrinsic volume of activation is −27±3 cm3/mol for the cycloadding process and −3.3±3 cm3/mol for the reverse reaction.
The Structure of the Cyclodextrin Complex. XII. Crystal Structure of α-Cyclodextrin-1-Phenylethanol (1:1) Tetrahydrate
Authors: Harata Kazuaki
Published: July 2006

The crystal structure of the α-cyclodextrin-1-phenylethanol (1:1) tetrahydrate, C36H60O30·C8H10O·4H2O, was determined by the X-ray method. The crystal is monoclinic, the space group being P21 with Z=2; the cell dimensions are a=8.176(1), b=23.930(2), c=13.853(1) Å, and β=106.69(1)°. The structure was solved by means of the Patterson map and the trial-and-error method combined with the rigid-body least-squares technique. Refinement was carried out by the block-diagonal least-squares method to the final R-value of 0.040 for 3565 reflections. α-Cyclodextrin molecules are stacked along the a axis in the head-to-tail fashion to form a channel-type structure, and are tilted by 17.0° against the channel axis. Owing to the lateral shift of α-cyclodextrin ring parallel to the molecular plane, neighboring α-cyclodextrin molecules along the channel are linked by only one weak hydrogen bond. The 1-phenylethanol molecule is sandwiched between stacked α-cyclodextrin molecules. S-(−) and R-(+) isomers of 1-phenylethanol are each located at the same position with the statistical disorder of the hydroxyl group with the occupancy of 0.5. Columns formed by the stack of α-cyclodextrin are closely packed, being linked with one another by many hydrogen bonds. Water molecules are located in two kinds of intermolecular spaces between α-cyclodextrin columns.
A Polarographic Study of Bis(benzoylacetonato)nickel(II) in Dimethyl Sulfoxide
Authors: Kudo Setsuko , Iwase Akio , Mogi Iwao , Tanaka Nobuyuki
Published: July 2006

The chemical equilibria of bis(benzoylacetonato)nickel(II) in dimethyl sulfoxide solutions were investigated, mainly by means of d.c. polarography. In 0.05–0.1 mol dm−3 NaClO4, TMAP, and TBAP solutions, the following chemical equilibria were found: Ni(bi-bzac)2\ightleftharpoonsNi(bi-bzac)(uni-bzac)\ightleftharpoonsNi(bi-bzac)+\ightleftharpoonsNi(uni-bzac)+ where bi- and uni- are the abbreviations of bidentate and unidentate respectively. The species of Ni(bi-bzac)2 and Ni(bi-bzac)(uni-bzac) comprised 35% and 57% respectively of the total complex of 1 mmol dm−3 in a TMAP or TBAP solution, while they accounted for 15% and 77% respectively in a NaClO4 solution. Such a difference in the equilibrium distribution was explained on the basis of the interaction between π electrons of the ligand and cations of the supporting electrolytes. The tris-complex was formed by the addition of excess benzoylacetonate to the complex solution.
Reactions of Thiols with Phenylglyoxal to Give Thiomandelic S-Esters. Formation of Hemithioacetals and Their Rearrangement
Authors: Okuyama Tadashi , Kimura Kazumasa , Fueno Takayuki
Published: July 2006

Equilibrium constants Kh for the addition of 2-mercaptoethanol and glutathione to phenylglyoxal to form hemithioacetals were determined spectrophotometrically over the pH range 7–10. The observed Kh values decrease sigmoidally with pH as the thiol ionizes. Rearrangement of hemithioacetals formed from phenylglyoxal and various thiols was kinetically investigated. The rates increase with thiol concentration following a saturation curve to give Kh identical with the spectrophotometric value. The rearrangement is subject to general base catalysis. The solvent isotope effect on the rate of the rearrangement, kH2O/kD2O, is nearly 1.0; that on the equilibrium, KhH2O/KhD2O, is 0.38. The results strongly support the mechanism involving proton transfers through an enediol intermediate.
Unusual Reaction of Azoxybenzenes with p-Toluenesulfonic Acid in Acetic Anhydride
Authors: Shimao Ichiro , Fujimori Ken , Oae Shigeru
Published: July 2006

Treatment of azoxybenzene with p-toluenesulfonic acid in acetic anhydride gave tosylates of 4- and 2-(phenylazo)phenols, and the corresponding acetates as by-product, besides azobenzene. However, a similar reaction of 4,4′-difluoroazoxybenzene gave 2-tosyloxy-4,4′-difluoroazobenzene as rearrangement product, besides 4-fluorophenyl tosylate and 4-fluorophenyl acetate. Meanwhile, the reaction of 4,4′-diacetoxyazoxybenzene afforded 4-acetoxyphenyl tosylate and hydroquinone diacetate in high yields. These unique reactions involve C–N bond cleavage, and may proceed through a pathway involving formation of benzenediazonium ion as the key intermediate.
A Stereoselective One-stage α-Glucosylation with 2,3,4,6-Tetra-O-benzyl-α-d-glucopyranose and a Mixture of Methanesulfonic Acid, Cobalt(II) Bromide, and Tetraethylammonium Perchlorate
Authors: Koto Shinkiti , Morishima Naohiko , Zen Shonosuke
Published: July 2006

A one-stage procedure for the stereoselective α-glucosylation of alcohol with 2,3,4,6-tetra-O-benzyl-α-d-glucopyranose and a mixture of methanesulfonic acid, cobalt(II) bromide, and tetraethylammonium perchlorate is described. The mechanism of the glucosylation reaction is discussed.
Solid-phase Synthesis of Substrate Model Peptides and Their Hydroxylation with Collagen Lysyl Hydroxylase
Authors: Kikuchi Yasuo , Tamiya Nobuo
Published: July 2006

The peptides, (Ala–Lys–Gly)10–Phe, (Ile–Lys–Gly)3–Phe, and (Ile–Lys–Gly)5–Phe, were synthesized by solid-phase fragment condensation method. The contaminating shorter peptides and branched chain peptides were removed by CM-cellulose column chromatography. The peptides were useful as synthetic model substrates for collagen lysyl hydroxylase. The –Ile–Lys–Gly– units in (Ile–Lys–Gly)5–Phe showed a higher affinity to the enzyme than those in (Ile–Lys–Gly)3–Phe. A strong substrate inhibition was observed with highly basic peptide, (Ala–Lys–Gly)10–Phe.
Six New Sesquiterpenoids from the Red Alga Laurencia nipponica Yamada
Authors: Suzuki Teruaki , Kikuchi Hajime , Kurosawa Etsuro
Published: July 2006

Six new laurane-type sesquiterpenoids were isolated from the red alga Laurencia nipponica Yamada and their structures were established on the basis of spectral and chemical evidence.
Infrared Spectra and Intramolecular Hydrogen Bonding of Some Salicylanilides of Pharmaceutical Interest
Authors: Endo Hiroko , Hirota Minoru , Ito Yoshio , Takeuchi Isao , Hamada Yoshiki
Published: July 2006

Intramolecular hydrogen bonding of the title compounds was investigated by measuring their infrared spectra in the OH, NH, and C=O stretching regions. The results showed that the intramolecular hydrogen bonding in the salicyloyl moiety plays an important role in the antibacterial activities of these salicylanilides.
Pyrene-cation Formation on Reactions of Pyrene Triplet State with Metal Ions in Caffeine-solubilized Aqueous Solution
Authors: Nosaka Yoshio , Kira Akira , Imamura Masashi
Published: July 2006

Quenching of triplet states of pyrene and other aromatic hydrocarbons by metal ions in caffeine-solubilized aqueous solution was investigated. The concomitant formation of aromatic cations was observed on quenching of triplet pyrene by Hg2+ and Fe3+ and triplet phenanthrene and benz[a]anthracene by Hg2+.
Apparent Molar Volumes of Water in Methanol and Tetrahydrofuran at 298.15 K
Authors: Sakurai Masao , Nakagawa Tsurutaro
Published: July 2006

The densities of water–methanol(MeOH) and water–tetrahydrofuran(THF) mixtures have been measured at 298.15 K. The apparent molar volumes of water, Vφ,w, have been derived as a function of concentration. The values of Vφ,w in MeOH increase monotonously with the concentration, while for THF solutions the Vφ,w curve passes through a minimum at low mole fraction of water. These are interpreted in terms of the formation of water–organic solvent and water–water hydrogen bonding.