bluuebunny/crossref_metadata_2025 huggingface dataset:
Nickel(II) Complexes of Schiff Bases Derived from Salicylaldehyde and Glycyl-aspartate or -glutamate. Application to a Selective Hydrolysis Reaction of Dimethyl Glycylaspartate and Glycylglutamate
Authors: Nakao Yasuo , Nakahara Akitsugu
Published: July 2006

Nickel(II) complexes of Schiff bases derived from salicylaldehyde and glycylaspartate or glycylglutamate were prepared and their structures were determined on the basis of electronic absorption and 1H NMR spectra. The relationship between structure of the chelates and stability of fused-ring systems was discussed in some detail, and was applied to a selective hydrolysis reaction of dimethyl glycylaspartate and glycylglutamate. Nickel(II) complexes of Schiff bases derived from salicylaldehyde and β-methyl glycylaspartate or γ-methyl glycylglutamate were obtained by a reaction between dimethyl glycylaspartate or glycylglutamate and bis(salicylaldehydato)nickel(II) in methanol containing sodium or potassium hydroxide.
Kinetics and Mechanism of the Oxidation Reaction of Bis(μ-dibutyldithiocarbamato-S,S′)-digold(I) by Halogens
Authors: Kita Hidetoshi , Itoh Kazuyuki , Tanaka Koji , Tanaka Toshio
Published: July 2006

Kinetics of the reaction of bis(μ-dibutyldithiocarbamato-S,S′)-digold(I), [Au(n-Bu2dtc)]2, with I2, IBr, and Br2 in dichloromethane was studied by the stopped-flow technique. A 1 : 1 charge-transfer (CT) complex, [Au(n-Bu2dtc)]2·X2 (X2=I2, IBr, and Br2), formed in the initial process of reaction was identified spectrophotometrically at −50 °C. The rates of reaction were almost the same for I2, IBr, and Br2, and independent of the both [Au(n-Bu2dtc)]2 and halogen concentrations. The reaction has been interpreted to proceed via the charge-transfer complex, [Au(n-Bu2dtc)]2·X2, which decomposes in a rate-determining step to give the final product, [AuIII(n-Bu2dtc)2][AuIX2]. The activation parameters for the reactions were determined: ΔH\eweq(kJ/mol)=43.7 (I2), 26.0 (IBr), and 12.3 (Br2); ΔS\eweq(J/mol K))=−91.5 (I2), −156 (IBr), and −201 (Br2).
Crystal Structure and Absolute Configuration of (+)546-cis(O)-Triammine-(sarcosinate-N-propionato)cobalt(III) (+)546-(Ethylenediamine-tetraacetato)cobaltate(III) Monohydrate
Authors: Okamoto Ken-ichi , Tsukihara Tomitake , Hidaka Jinsai , Shimura Yoichi
Published: July 2006

The crystal structure of (+)546-cis(O)-triammine(sarcosinate-N-propionato)cobalt(III) (+)546-ethylenediaminetetraacetato)cobaltate(III) monohydrate was solved by single crystal X-ray diffraction techniques. The crystal is orthorhombic, space group P212121, with a=10.792, b=26.816, c=8.203 Å, and Z=4. The final R value was 0.054. The absolute configurations of two complex ions were determined by means of anomalous dispersion using Cu Kα radiation. The coordinated asymmetric nitrogen atom of sarcosinate-N-propionate ligand takes an R configuration, and the (+)546-(ethylenediaminetetraacetato)cobaltate(III) ion Δ one.
Study of the Quasi-pcaks in the Ion Cyclotron Double Resonance
Authors: Aoyagi Katsuyuki
Published: July 2006

Quasi-peaks which do not correspond to any reactant ion in the ion-molecule reaction were observed in the ion cyclotron double-resonance spectrum. The field-sweep quasi-ICDR spectrum was also observed. Expressions giving the frequencies of the quasi-peaks observed in the ion cyclotron double-resonance spectrum were obtained; the results agreed with those obtained previously. Both the ion mass and ion drift-voltage dependences of the quasi-peaks were shown. A close agreement between the calculated and measured values was obtained. A method to repress the quasi-peaks is discussed.
Chemical Transformation of Seldomycin 5 into 3′-Deoxyseldomycin 5 and Related Compounds
Authors: Matsushima Hideo , Mori Yasuki , Kitaura Kozo
Published: July 2006

3′-Deoxyseldomycin 5 (2), 2′-deamino-3′-epiamino-3′-deoxyseldomycin 5 (14), and 2′,3′-epimino-2′-deamino-3′-deoxyseldomycin 5 (15) were prepared from seldomycin 5 (1). Treatment of hexa-N-ethoxycarbonyl (ecb)-3′-O-tosylseldomycin 5 with sodium borohydride in DMSO gave the corresponding N-ecb-derivatives of 2, 14, and 15. Removal of the ecb groups of these compounds with aq potassium hydroxide gave the free bases 2, 14, and 15, respectively. Structure determination of the products was performed by means of MS, CMR, PMR, and chemical reactions. It was found that 2 exhibits a more potent and broader antibacterial activity than the parent compound 1, and 14 shows unique antibacterial spectrum against resistant strains, whereas 15 has almost no activity.
Enantioface-Differentiating (Asymmetric) Hydrogenation of β-Ketoester with Modified Raney Nickel Catalyst (MRNi). XXXI. A Comparative Study of Reaction Rates and Optical Yields
Authors: Ozaki Hiroshi , Tai Akira , Kobatake Shinzo , Watanabe Hironobu , Izumi Yoshiharu
Published: July 2006

Enantioface-differentiating hydrogenations of methyl acetoacetate over (S)-alanine-, (S)-2-aminobutyric acid, (S)-valine-, (S)-leucine-, (S) -malic acid-, and (R,R)-tartaric acid-MRNi were carried out under atmospheric pressure of hydrogen and the effects of the modifying reagent on the rates of the formation of enantiomer, vS and vR, were investigated. The rates of hydrogenation, v=vS+vR, were the same for all the amino acid-MRNi and also for all the hydroxy dicarboxylic acid-MRNi. However, the vR⁄vs ratios were different. These results are explained in terms of the independence of the rate-determining and enantioface-differentiating steps in the reaction pathway of hydrogenation. The rate-determining step of hydrogenation was shown to be the hydrogen addition to the adsorbed substrate, while the enantioface-differentiating step was expected to occur prior to the rate-determining step.
Volatile Components of Meratia praecox
Authors: Naya Yoko , Kotake Munio
Published: July 2006

The major volatile constituents present in different parts of a deciduous tree, Meratia praecox, have been identified by combination of GC-MS and spectral analysis of the isolated compounds. From the results, some biogenetic implications were discussed.
Studies of the Azulenes. V. Condensation Products of Guaiazulene and 4,6,8-Trimethylazulene with Active Methylene Compounds by Means of Selenium Dioxide. Molecular Asymmetry Induced by Chelate Ring and Its Anisotropy Effect
Authors: Kohara Kazuko
Published: July 2006

In the presence of selenium dioxide, guaiazulene and 4,6,8-trimethylazulene condensed with the active methylene compounds, ethyl acetoacetate and acetylacetone, to give ethyl α-(3-guaiazulenyl)acetoacetate (3a), α-(3-guaiazulenyl)acetylacetone, ethyl α-(4,6,8-trimethyl-1-azulenyl)acetoacetate (5a), and α-(4,6,8-trimethyl-1-azulenyl) acetylacetone. These α-substituted β-diketones exist exclusively in their corresponding enol forms, as evidenced by their NMR spectra. In the NMR spectra of 3a and 5a, the ethyl protons of the ester group show an ABX3 pattern; the observed nonequivalence of the methylene protons is attributable to the restricted rotation between azulene and the substituent carbon atoms. From an inspection of the chemical shifts of the methyl group of metal chelate compounds of azulene derivatives, it is now reasonably concluded that there is no aromaticity associated with the chelate ring, providing further support for Musso’s proposal.
Stark Effect on the Electronic Bands of a Symmetric-top Molecule
Authors: Amako Yoshito , Sato Yoshi-ichi , Watanabe Akiyoshi
Published: July 2006

Calculations have been performed on the energy matrix of a rigid symmetric-top molecule, HCHO, in order to determine the transition energies and intensities of the rotational sub-bands of the electronic spectrum under various magnitudes of external electrostatic fields. Though HCHO is an asymmetric-top molecule, the rotational structure of the 3390 Å band of this molecule is close to that of a perpendicular band of a symmetric-top molecule, at least, for not too small values of K. The variation in the band structures with the applied fields can be illustrated by the behavior of several selected bands, pP, pQ, rR, and rQ. Below 100 kV/cm, the overall Stark splittings have been linearly dependent on the field strength, regardless of the branch types. Over 100 kV/cm, however, a deviation from the linear dependence has been found for a certain branch. Changes in the band shape have appeared at such small values of external fields that no deviation from the linear field dependence of the overall Stark splitting has been observed. Such changes are dependent on the branch types, especially in the cases of branches with small J values and with K<J. The intensity enhancement of some forbidden bands has also been observed, the magnitude of which is proportional to the square of the field strength below 100 kV/cm. However, the relation between the intensity enhancement and the electric fields has been found to be complicated at fields over 100 kV/cm, the enhanced intensity being proportional to a coupled sum of E2 and higher terms. At a fixed electric field, a linear relation has been found between the overall Stark splitting and the various μ values assumed for the excited state. The analysis of the data has enabled us to determine the electric dipole moment of the lowest n→π* excited state of HCHO as 1.65 D.
Study on Zinc O,O-Diisobutyl Dithiophosphate as Antioxidant
Authors: Ohkatsu Yasukazu , Kikkawa Kazumi , Osa Tetsuo
Published: July 2006

Cumyl hydroperoxide has been decomposed using zinc O,O-diisobutyl dithiophosphate. The decomposition reaction consisted of three stages including the first homolytic decomposition and the last heterolytic decomposition. These decomposition modes depended considerably on the relative concentration of the complex to the hydroperoxide and the total concentration. From these results and on the basis of decomposition reaction in the presence of both zinc O,O-diisobutyl dithiophosphate and bis(O,O-diisobutoxyphosphonothioyl) disulfide, it has been shown that the formation of sulfuric acid was most important for heterolytic decomposition.
Preparation of Alkylthio- and Phenylthio(triphenylphosphine)copper(I) Complexes and Their Catalytic Activity for Transesterification of S-Alkyl Ethanethioates and Thiols
Authors: Kubota Minoru , Yamamoto Akio
Published: July 2006

Alkylcopper complexes, RCu(PPh3)2 (R=methyl, ethyl, propyl, isobutyl)reacted with sulfur smoothly at low temperatures to produce dialkyl disulfides. This indicates the insertion of sulfur to alkyl-Cu bond taking place followed by coupling of the two alkylthio–Cu bonds. Methylcopper complex, CH3Cu(PPh3)2·0.5Et2O reacted with thiols to produce alkylthio- and phenylthiocopper complexes having one or two triphenylphosphine ligands. The reactions of these alkylthiocopper complexes with acyl halides and acid anhydrides produced S-alkyl ethanethioates in high yields, whereas the reactions of alkylthiocopper complexes with alkyl halides produced dialkyl sulfides. Alkylthio- and phenylthiocopper complexes were found to catalyze the transesterification reactions between S-alkyl ethanethioates and thiols. The exchange reactions also take place between the alkylthiocopper complex and benzenethiol producing phenylthiocopper complex with liberation of alkanethiol.
The Hydrocracking of Alkyl-substituted Polynuclear Aromatic Hydrocarbons over ZnCl2/CuCl Molten Salt Catalyst
Authors: Nakatsuji Yohji , Ikkaku Yasuhiko , Nomura Masakatsu , Kikkawa Sh\={o}ichi
Published: July 2006

The hydrocracking of alkyl derivatives of polynuclear aromatic hydrocarbons (naphthalene, anthracene, dihydroanthracene, phenanthrene, and dihydrophenanthrene) over ZnCl2/CuCl molten salt was examined at 400 °C for 3 h in a batch autoclave system. The kinds of alkyl groups, the positions of the alkyl groups, and the types of condensed rings were changed in order to clarify the decomposition process of the polynuclear aromatic hydrocarbons. On the basis of the detailed product distribution obtained by using GC-MS, the behavior of the alkyl group attached to the condensed ring under these reaction conditions was found to be different. Generally, in this investigation, the alkyl group was not completely dealkylated in the initial stage and remained in the products as monocyclic aromatics; the extent of dealkylation was found to be dependent upon the type of starting materials. In the hydrocracking of 9,10-dihydroanthracene, dehydrogenation occurred in preference to the opening of the central ring.
The Reaction of Thio-substituted Cyclopropenium Ions with Iminopyridinium and Sulfonium Ylides
Authors: Inoue Shinichi , Yasuda Gorou , Hori Takuya
Published: July 2006

The reaction of several thio-substituted cyclopropenium ions with iminopyridinium and sulfonium ylides in organic solvents at reflux and room temperature under N2 gave N,N′-dicyclopropenylidene urea derivatives, together with some unidentified compounds.
Reactions of Benzyl 2-Benzyloxycarbonylamino-2-deoxy-3-O-mesyl-α-d-gluco- and -α-d-allopyranoside Derivative with Iodide
Authors: Sano Hiroshi , Iimura Seiji , Tsuchiya Tsutomu , Umezawa Sumio
Published: July 2006

The reactions of benzyl 4,6-O-benzylidene-2-benzyloxycarbonylamino-2-deoxy-3-O-mesyl-α-d-glucopyranoside (1), its N-methyl derivative (4) and 3-epimer (8) with sodium iodide in DMF were studied. Compound 1 gave several products including 2,3-alloepimine, 4 an oxazolidinone and 8 a 3-iodo derivative.
Cyclohexadienyl Radicals in γ-Irradiated catena-μ-Ethylenedi aminecadmium(II) catena-Tetra-μ-cyanomercurate(II)–Benzene (1/2) and the Analogous Clathrates
Authors: Iwamoto Toschitake , Kiyoki Mamoru , Matsuura Niro
Published: July 2006

Cyclohexadienyl radicals produced by γ-ray irradiation are thermally stable up to 423 K in the mother benzene clathrates Cd(en)Hg(CN)4·2C6H6, Cd(en)Cd(CN)4·2C6H6, Cd(tn)Hg(CN)4·2C6H6, and Cd(NH3)2Hg(CN)4· 2C6H6. However, no thermally stable C6H7· radicals have been observed in Cd(NH3)2Ni(CN)4· 2C6H6 and Cd(en)Ni(CN)4·2C6H6 even immediately after irradiation. The ESR spectra of C6H7· show the hyperfine splitting constants of the methylene, para, ortho, and meta protons 48, 13, 9, and 3 G, respectively.
The Construction of an Energy-dispersive X-Ray Diffractometer for Liquids and Its Application to CCl4
Authors: Murata Yoshitada , Nishikawa Keiko
Published: July 2006

An energy-dispersive X-ray diffractometer using a solid-state detector is constructed for the determination of the liquid structure. It has two merits over the usual angle-dispersive diffractometer, i.e., a higher resolution of the s-value and a wider measurable s-region. The procedure of the data analysis and the results for liquid CCl4 are described. The absorption correction is important in the reflection method. By taking advantage of the energy-dispersive method, it is shown that liquid CCl4 has a long-range correlation at room temperature.
The Molecular Sieving Action of Ion-exchanged Zeolites A
Authors: Ohgushi Tatsuo , Yusa Atsushi , Kinoshita Kunio , Yatsurugi Yoshifumi
Published: July 2006

K12-A zeolite was ion-exchanged with Mg2+, Mn2+, Co2+, Cd2+, or Pb2+, and molecular sieving properties of the resultant zeolites were studied, mainly for PH3 and SiH4. (K, Mg)-A and (K, Mn)-A adsorbed PH3 but not SiH4, and hence are usable as a purifier for SiH4. (K, Co)-A, (K, Cd)-A, and (K, Pb)-A decomposed both PH3 and SiH4, and are unsuitable as an adsorption purifier for SiH4. By using adsorption columns containing (K, Mn)-A or (K, Mg)-A, breakthrough curves were obtained for PH3 in SiH4. The breakthroughs of (K, Zn)-A and (K, Ca)-A columns were also measured for comparison. The breakthrough point increased in the order of (K, Ca)-A<(K, Mg)-A<(K, Mn)-A<(K, Zn)-A. The mechanism of the molecular sieving is discussed. It is concluded that introduced bivalent cations increase the Debye-Waller factor of K+ blocking the windows. A large Debye-Waller factor causes a decrease in the activation energy required for adsorbate molecule to pass through the blocked window.
ESR Spectra of Bis(acetylacetonato)oxovanadium(IV) and Related Chelates in Molten o-Terphenyl and Some Other Organic Compounds
Authors: Matsunaga Yoshio
Published: July 2006

All the patterns from the isotropic ESR spectrum to the anisotropic one of bis(acetylacetonato)oxovanadium(IV) and related chelates are recorded by employing molten o-terphenyl as a solvent and by changing the temperature above and below the melting point. The results are qualitatively explained in terms of the anisotropic molecular motion and are considered to be evidence for the presence of clusters in the melt. Similar observations are made with some derivatives of 2,4,6-trinitrodiphenylamine, but only partially with m-terphenyl and the 3′-methoxy and 3′-ethoxy derivatives of 2,4-dinitrodiphenylamine. The implications of the results concerning the structure of the melts are discussed.
Thermal Decomposition of CF3CN in Shock Waves
Authors: Okada Kazuo , Kajimoto Okitsugu , Fueno Takayuki
Published: July 2006

The thermal decomposition of CF3CN diluted to 0.2 and 0.5 mol% in argon was studied behind incident shock waves over the temperature range 2450–3610 K. Mass spectrometry of the reaction mixture revealed that the decomposition products are C2F6, C2N2, C2F4, and a trace of FCN. The course of the primary process of decomposition, CF3CN+Ar→CF3+CN+Ar, was followed by monitoring the CN(0–1) violet absorption centered at 421.5 nm. It was confirmed that the reaction is still in the low-pressure limit under our experimental conditions. The initial slope of absorption gave the bimolecular rate constant, k=(7.9±3.1)×1015exp[−(94.0±2.8) kcal mol−1⁄RT] cm3 mol−1 s−1. The rate constants obtained are best fitted by the classical collision-theory expression k=λ(Z⁄n!)(E⁄RT)nexp(−E⁄RT) with λ=0.44, n=2, and E=D0(CF3–CN)=102.7 kcal/mol. The mechanism of the overall decomposition was suggested and checked by numerical integrations of the relevant rate equations.
Conductivities of the Methyl Orange–Dodecyltrimethylammonium Complex in Dioxane–Water Mixtures
Authors: Mitsuishi Masaru , Yamaguchi Yuzoh , Ishii Naoko
Published: July 2006

The ionic-association reaction of the complex between the Methyl Organic anion and the dodecyltrimethylammonium cation in dioxane–water mixtures has been studied by analyzing the conductivity data. The equivalent conductivities at an infinite dilution and the ionic association constants (KA) have been determined by means of Shedlovsky’s treatment, and they have been compared with those of Methyl Orange (sodium salt). The KA values have been seen to increase with a rise in the temperature and with an increase in the dioxane content. The Walden products have been essentially constant, and they have been found to be comparable to those of Methyl Orange (sodium salt). The data have been analyzed further by the use of the Denison-Ramsey equation, and the ion-ion distance in an associate has been obtained. The ionic-association reaction have been found to increase the heat content and also the entropy.
Adsorption of 1,2-Propanediol and Methyl Cellosolve at Mercury— 0.10 m KCl aq Interface at 25 °C
Authors: Ramanamurti M V , Apparao B V
Published: July 2006

Adsorption of 1,2-propanediol and methyl cellosolve (isomeric compounds) at Hg–0.10 m KCl (aq) solution interface evaluated through equilibrium double layer capacity measurements indicated congruency of adsorption isotherms with respect to both potential (E) and charge density (σM); applicability of Langmuir’s adsorption isotherm; quadratic dependence of Δ\barG° on E and single stable orientation with the hydrocarbon chain facing the electrode and functional group in solution throughout the coverage region, for both the compounds. Surface excess, standard free energy of adsorption and the anodic shift of Epzc, are greater while the charge corresponding to maximum adsorption is more negative, for methyl cellosolve than for the diol.
Oxidation of Azide by Peroxodisulf ate in Aqueous Medium
Authors: Ponnuraj V , Ramachandran M S , Vivekanandam T S , Chandra Singh U
Published: July 2006

Results on the oxidation of N3− by peroxodisulfate in neutral and acid media are presented. The rate of the reaction is found to be proportional to [N3−] and [S2O82−] directly. The product of oxidation is found to be pure nitrogen. The stoichiometry of the reaction is

S2O82−+2N3−=2SO42−+3N2.

The reaction shows positive salt effect. Thermodynamic activation parameters ΔH≠ and ΔS≠ have been calculated for this reaction. It is observed that H+ ion inhibits the reaction. The mechanism is discussed in terms of the kinetic results.
Studies of the Hydrous Titanium Oxide Ion Exchanger. III. Distribution Coefficients and Some Applications
Authors: Inoue Yasushi , Tsuji Masamichi
Published: July 2006

In order to understand the cation-exchange behavior of hydrous titanium oxide, the distribution coefficients of various cations were measured as a function of the pH and the ionic strength. The order of selectivity for alkali metal ions is Cs+>Rb+>K+>Na+, for alkaline earth metal ions, Ba2+>Sr2+>Ca2+, and for bivalent transition metal ions, Zn2+>Cu2+>Co2+. From the dependency of the distribution coefficients on the pH, it is concluded that the apparent dissociation constants of the exchanger reported previously are not constant, but gradually decrease with the pH of the medium. By using ammonium chloride and ammonium nitrate solutions as eluents, nearly quantitative separations of 137Cs–133Ba and 137Cs–89Sr were achieved with a relatively small column.
Synthesis and Reactions of Some New 1,3-Dioxa-2-bora Heterocycles Derived from o-Hydroxybenzyl Alcohol
Authors: Srivastava G , Bhardwaj P N
Published: July 2006

2-Isopropoxy-4H-1,3,2-benzodioxaborin(I), obtained from isopropyl borate and o-hydroxybenzyl alcohol, reacts with a variety of hydroxy compounds (viz., t-butyl alcohol, phenol, ethane- 1,2-diol, 2-aminoethanol, o-amino phenol) and acetic anhydride to give the corresponding 2-substituted heterocycles. Reactions of (I) as well as other 1,3-dioxa-2-bora heterocycles with bases (viz., ammonia, triethylamine, pyridine, dimethylformamide) show that the electrophilicity of boron decreases in the order: 2-alkoxy-1,3,2-benzodioxaborole>2-phenoxy-4H-1,3,2-benzodioxaborin>(I)>2-alkoxy-1,3,2-dioxaborinane.

Codisproportionation reaction between bis(4H-1,3,2-benzodioxaborin-2-yl)oxide (obtained directly from boric acid and o-hydroxybenzyl alcohol) and triorganotin hydroxide or oxide yields 2-triorganostannoxy-4H-1,3,2-benzo-dioxyborin. Cleavage and insertion reactions of these compounds have been studied.
Photoaddition Reaction of N-Acetyldiphenylmethyleneamine with Cyclic and Acyclic Olefins. An Example of Heavy Atom Effect in Photoreaction
Authors: Toshima Naoki , Asao Shuichiro , Hirai Hidefumi
Published: July 2006

Irradiation of N-(diphenylmethylene)acetamide (N-acetyldiphenylmethyleneamine, 1) in cyclopentene gave N-[1,1-diphenyl-1-(cyclopenta-2′-enyl)niethyl]acetaniide, the addition product of cyclopentene to the C=N bond of imine 1, in 31% yield. The photoreaction of 1 was observed in other cyclic and acyclic olefins. The reactivity of the olefins decreases in the order; cyclopentene>cyclohexene>cyclooctene>2-pentene\simeq2-hexene. The photoreaction is promoted by the presence of the heavy atom solvent or the sensitizer. The mechanism of photoreaction is discussed in terms of the excited triplet state of the imine.
Dehalogenative Coupling of gem-Dihalides and Benzyl Halides by Means of Hexacarbonyltungsten(0) and Related Compounds
Authors: Fujiwara Yuzo , Ishikawa Ryuichi , Teranishi Shiichiro
Published: July 2006

W(CO)6 and WCl6–LiAlH4 systems have been found to cause coupling of gem-dihalides and benzyl halides giving olefins and bibenzyl derivatives, respectively. The tungsten reagents also cause coupling of some alcohols. The carbene intermediate was suggested from the formation of a cyclopropane derivative.
Organic Photochemical Reactions. XXVI. Photoaddition of Singlet and Triplet Methyl Pyruvate with 2,3-Dimethyl-2-butene
Authors: Shima Kensuke , Sawada Taisuke , Yoshinaga Hiroyuki
Published: July 2006

UV irradiation of methyl pyruvate in the presence of 2,3-dimethyl-2-butene leads to the formation of four primary photo-products in reasonable quantum yield: two unsaturated ethers (1 and 2) and two unsaturated alcohols (3 and 4). The effects of olefin concentration on the quantum yield of product formation, as well as quenching studies, suggest that 3 and 4 are formed from the excited singlet state of methyl pyruvate, while 1 and 2 are produced from the triplet state of methyl pyruvate. The role of exciplexes in this reaction is discussed. Quenching data of fluorescence of methyl pyruvate and the kinetic analysis of this reaction support these considerations.
Polarographic Behavior of Chloramine-T in an Alkaline Solution at a Rotating Platinum Electrode
Authors: Matsuda Toshio
Published: July 2006

Chloramine-T in alkaline solutions at pH higher than 8 gives a single reduction wave at a rotating platinum electrode. This wave results from the two-electron reduction of the anionic species of N-chloro-p-toluenesulfonamide. The electrode reaction is polarographically irreversible. Reproducible waves were observed with a freshly reduced electrode. The diffusion current was proportional to the concentration over the range from 0.05 to 0.6 mM chloramine-T.
The Reaction of Cyclohexyl Isocyanide with Aromatic Diacyl Disulfides
Authors: Tanaka Sakuya , Masue Kenji , Okano Masaya
Published: July 2006

The reaction of cyclohexyl isocyanide with dibenzoyl disulfide in toluene at a reflux temperature gives cyclohexyl isothiocyanate, together with some unidentified compounds. Based on the substituent effects on the rate, a probable reaction path is proposed. The distinction between two reactions conducted in the absence and in the presence of soft metal salts is also described.
A Convenient Method for the Introduction of 1,3-Dithiolan-2-yl Group into Active Methylene Compounds
Authors: Tanimoto Shigeo , Matsumura Yasuo , Sugimoto Toyonari , Okano Masaya
Published: July 2006

The reaction of 2-ethoxy-1,3-dithiolane with a variety of active methylene compounds in the presence of a zinc chloride catalyst was investigated. By this reaction the introduction of a 1,3-dithiolan-2-yl group into the active methylene compounds was achieved. Some behavior of the 1,3-dithiolan-2-yl derivative of ethyl acetoacetate, which is one of the newly obtained compounds, was also briefly examined.
Studies on Heterocyclic Analogs of Azulenes. IlI. The Reactions of 2-Chloro-3-ethoxycarbonylcyclohepta[6]pyrroIe with the Carb-anions Derived from Active Methylene Compounds
Authors: Abe Noritaka , Nishiwaki Tarozaemon
Published: July 2006

2-Chloro-3-ethoxycarbonylcyclohepta[b]-pyrrole reacts with the carbanions derived from active methylene compounds to give substitution products and/or addition products depending on the reaction conditions.
A Carbon-13 Spin-Lattice Relaxation Study of Side Chains of Poly(alkyl methacrylate)
Authors: Hirai Yoshiyuki , Ito Taizo , Imamura Yoshio
Published: July 2006

The carbon-13 spin-lattice relaxation times (T1) of the carbons in the alkyl side chains of poly (alkyl methacrylate) (butyl, octyl, dodecyl, and octadecyl), including poly (butyl methacrylate) of low molecular weights, were determined from partially-relaxed Fourier transform spectra. The T1 for polymers of high molecular weights were found to be determined by the internal motion of the side chains, and not by the overall motion of the polymer molecules. The relaxation data indicate that the internal motion of the short side chains (butyl and octyl) is restricted by interactions between the side chains, although this effect was ineffective near the free ends of long chains (dodecyl and octadecyl). These observations are interpreted in terms of the local environment around the side chains.
The application of an Improved d.c. Polarization Technique to the Electronic Conductivity Measurements of α-AgI and AgBr
Authors: Mizusaki Junichiro , Fueki Kazuo , Mukaibo Takashi
Published: July 2006

An improvement was made in the d.c. polarization technique which is used for the measurement of the electronic conductivity of solid electrolytes. In the electrochemical cell, Ag/AgX (X=Br or I)/carbon, the carbon electrode was sealed with AgX in the bottom of a Pyrex tube so that the electrode reaction at the AgX/carbon interface could be suppressed in the steady state. Using the improved d.c. polarization cell, measurement was made of the electronic conductivity of AgI in the temperature range from 330 to 500 °C, and that of AgBr, at temperatures from 375 to 400 °C, as a function of the halogen partial pressure, PX2. It was found that the electronic conduction of α-AgI is p-type and that the electronic conductivity is proportional to PI21⁄2. The electronic conductivity of AgBr was found to be proportional to PBr2−1⁄2 in a low-pressure range of bromine, and proportional to PBr21⁄2 high-pressure range.
Nuclear Quadrupole Resonances of Phosphorus Iodides and Some Phosphorus Trihalide–Boron Trihalide Complexes
Authors: Terao Hiromitsu , Okuda Tsutomu , Negita Hisao
Published: July 2006

Nuclear quadrupole resonance (NQR) frequencies due to 79Br and 127I are examined in phosphorus iodides, PI3 and P2I4, and the complexes PBr3·BBr3, PBr3·BI3, and PI3·BBr3. The quadrupole coupling constants and asymmetry parameters are also derived for 127I in PI3, P2I4, and PBr3·BI3. The resonance lines of PI3 fade out above 257 K, at which temperature a structural phase transition is suggested. The number of resonance lines in P2I4 shows that the molecular symmetry of P2I4 is \bar1 instead of 2/m in its crystal. The similarity of the resonance patterns of the three complexes indicates that they are isomorphous with one another. The electronic structures of the halogens in the compounds mentioned above have been discussed by using the Townes-Dailey theory. On complexing, the electric charge of the halogen atoms in the donor PX3 decreases due to the polarization of pσ bonds, whereas that of the halogen atoms in the acceptor BY3 increases owing to the backdonation through pπ bonds.
On the Diffusivity of Nonelectrolytes in Infinitely Dilute Solution
Authors: Nakanishi Koichiro
Published: July 2006

The validity of the plot, isoviscous diffusion coefficient D1η2  vs. molar volume V2, where D1 is the diffusion coefficient of solute at infinite dilution, η2 the viscosity coefficient of solvent, and V2 the molar volume of solvent, proposed by Hammond and Stokes for carbon tetrachloride, was examined and confirmed with several solutes. General features of the behavior of diffusivity in dilute solution are discussed in terms of solvent association, complex formation and other factors. The experimental results for iodine are given.
Thermodynamic Study on Adduct Formation of Copper(II) β-Diketonates with Heterocyclic Bases
Authors: Ueda Kazumasa
Published: July 2006

The stability constants and thermodynamic functions for 1:1 adduct formation of unidentate heterocyclic bases with copper(II) β-diketonates were determined in non-aqueous solvents by the spectrophotometric method. The main factors controlling the stability of the adducts were investigated and the bases were classified into two groups in adduct formation from the plots of the stability constants against pKH values of the bases: steric hindered and unhindered bases. Large negative entropy changes were observed for pyridine, β-picoline, and γ-picoline; these were ascribed to the π-bond character of the adduct bonds. A solvent effect was observed; the order of increasing adduct stability was as follows: acetone <butyl acetate <4-methyl-2-pentanone <chloroform <nitrobenzene <toluene \simeq benzene <chlorobenzene. This order agreed with the decreasing order of the solvent-chelate interaction and of the solvent-base interaction. In all cases, the adducts were stabilized by large exothermic enthalpy changes. Moreover, the introduction of a CF3 group into β-diketones also brought about a considerable entropy change which promoted the stabilization of the chelate. The effect of the other terminal groups was not clearly observed.
A Molecular Orbital Study of Silylated Carbenes
Authors: Noyori Ryoji , Yamakawa Masashi , Ando Wataru
Published: July 2006

The geometry and electronic properties of methylene, methylcarbene, carboxycarbene, phenylcarbene, trimethylsilylcarbene, silylcarbene, carboxysilylcarbene, and phenylsilylcarbene have been determined by MINDO/3 calculation. Introduction of a silyl group results in considerable decrease in ionization potential of carbenes. The electron affinity is increased to some extent by such substitution. The computation suggests a bent geometry for optimized triplet trimethylsilylcarbene structure, in conflict with a recent postulate that the ground-state molecule has an essentially linear structure.
Reaction of Organic Tin(II) Compounds with Ethyl Isocyanate
Authors: Wakeshima Ikuko , Kijima Ichiro
Published: July 2006

The reaction of Sn–OC bond-containing tin(II) compounds with ethyl isocyanate was investigated. From the νNC0 absorption bands, it is recognized that the reactivity, in terms of tin(II) compounds, decreases in the order: bis[2-(dimethylamino)ethoxo]tin(II) > bis[o-(ethoxycarbonyl)phenolato]tin(II) > di(phenolato)tin(II)>bis(ethoxycarbonylacetonato)tin(II)>bis(3-ethoxycarbonyl-2-pentanoato)tin(II)>bis(1-phenylbutane-1,3-dionato)tin(II)>bis(dibenzoylmethanato)tin(II). Bis[2-(dimethylamino)ethoxo]tin(II), bis[o-(ethoxycarbonyl)phenolato]tin(II), and di(phenolato)tin(II) yielded triethyl isocyanurate as a main product from reactions with ethyl isocyanate, while bis(ethoxycarbonylacetonato)tin(II), bis(3-ethoxycarbonyl-2-pentanoato)tin(II), bis(1-phenylbutane-1,3-dionato)tin(II), and bis(dibenzoylmethanato)tin(II) gave mixtures of the isocyanurate and 6-ethylimino-1,3,5-triethylhexahydro-1,3,5-triazine-2,4-dione. The mechanism for the formation of these products is discussed.
Structure of Aloenin, a New Biologically-active Bitter Glucoside from Aloe arborescens var. natalensis
Authors: Hirata Toshifumi , Suga Takayuki
Published: July 2006

Aloenin, a new bitter glucoside with an inhibitory activity for the gastric juice secretion of rats, was isolated from the leaves of Aloe arborescens Mill. var. natalensis Berger, and the structure was confirmed to be 4-methoxy-6-(2-β-d-glucopyranosyloxy-4-hydroxy-6-methylphenyl)-2-pyrone by means of chemical, spectroscopic, and X-ray crystallographic methods. Ambiguity in the assignment of 2-pyrone-ring carbon signals was clarified by examination of the 13C-NMR spectra of aloenin and the related compounds.
Analysis of Thermal Desorption Curves for Heterogeneous Surfaces. I. A Linear Variation of the Activation Energy of Desorption
Authors: Tokoro Yasuo , Misono Makoto , Uchijima Toshio , Yoneda Yukio
Published: July 2006

This paper deals with the analysis of the desorption curves for heterogeneous surfaces, where the activation energy of desorption, Ed, linearly depends on surface coverage, θ, i.e., Ed=Ed0+α(1−θ) Computer simulation resulted in a characteristic change of curve shapes corresponding to the variation of desorption rate parameters, Ed0, A and α. By means of empirical parameters characterizing the peak shapes such as peak temperature, half width and symmetry factor, we were able to obtain a set convenient and valid equations for estimating the rate parameters. The curve fitting method was also investigated and found to be more precise, the equations obtained being very useful for giving an initial set of values for this method. The two methods were applied to the thermal desorption curves of CO2 on TiO2, and found to be useful and reliable.
The Syntheses of [3]- and [4]Ruthenocenophanes
Authors: Kamiyama Shin-ichi , Suzuki Toshishige M , Kimura Tetsuo , Kasahara Akira
Published: July 2006

[3]- and [4]ruthenocenophanes as well as other ruthenocene derivatives were synthesized. The preparation of ruthenocenes in this experiment required more forced reaction conditions than those of the corresponding ferrocenes. Two cyclopentadienyl rings of these ruthenocenophanes are found to tilt mutually, and the degree of the ring-tilting of [3]ruthenocenophane is greater than that of the [4] homolog.
13C NMR Chemical Shifts and Cationic Reactivity of Linear Conjugated Dienes
Authors: Hasegawa Kan-ichi , Asami Ryuzo , Takahashi Kensuke
Published: July 2006

The chemical shifts of the C1 and C2 of trans-1-alkyl-1,3-butadienes were correlated with Taft’s σ*, the proportionality constants being −35.9 and 12.3 ppm/σ*, respectively. The values 6.2 and −43.6 ppm/σ* were obtained for the C1 and C2 of 2-alkyl-1,3-butadienes, respectively. The observed chemical shifts of disubstituted butadienes roughly agreed with the values estimated from those of monosubstituted butadienes by means of additivity relationship. The cationic reactivity of linear conjugated dienes should be determined by the magnitude of the steric restriction of substituents and that of the stability of the resulting cation.
The Reaction of 2,4,6-Trimethylbenzonitrile N-Oxide with Polysubstituted p-Benzoquinones
Authors: Shiraishi Shinsaku , Ikeuchi Satoru , Sen\={o} Manabu , Asahara Teruzo
Published: July 2006

The reaction of 2,4,6-trimethylbenzonitrile N-oxide with various di- and tetrasubstituted p-benzoquinones and the structures of the products were studied. All of the tetrasubstituted quinones gave dioxazole derivatives through addition at the carbonyl site, whereas the disubstituted quinones gave dioxazoles or isoxazoline derivatives depending on the substituents. The reactivity of the quinone carbonyl toward the nitrile oxide varies with the substituents and with the substitution pattern; this phenomenon is discussed in terms of the resonance and inductive effects of the substituents.
The Crystal and Molecular Structure of 4-(1-Hydroxy-2,6,6-trimethyl-2-cyclohexenyl)-3-buten-2-one
Authors: Ueda Hideo , Katayama Chuji , Tanaka Jiro
Published: July 2006

The crystal and molecular structure of a hydroxy derivative of α-ionone, 4-(hydroxy-2,6,6-trimethyl-2-cyclohexenyl)-3-buten-2-one, was studied by means of X-ray analysis. The atoms including the conjugated double bond in the side chain and those around the double bond in the ring form planes orthogonal to each other.
Uptake of Ammine-Cobalt(III) Complexes into Escherichia Coli Cells
Authors: Tanabe Kiyoshi , Fujiwara Kitao , Fuwa Keiichiro
Published: July 2006

The uptake of Co into E. coli cells was studied in various Co(III) ammine complexes. It was found to be independent of the incubating temperature and existence of Mg2+ ion, but dependent on the ligands, the uptake of Co being in the following order. [Co(NH3)4(OH2)2]2(SO4)3>[Co(NH3)5(OH2)]Cl3>[Co(NH3)6]Cl3>>[Co(en)3]Cl3>[Co(OH2)6]Cl2
Alicyclic Terpenoids from Cyclocitryl Phenyl Sulfides. VI. Syntheses of β-Ionone Derivatives
Authors: Torii Sigeru , Uneyama Kenji , Kawahara Ichiro
Published: July 2006

4-(2,6,6-Trimethyl-3-oxo-1-cyclohexenyl)-3-buten-2-one and 4-(2,6,6-trimethyl-1,3-cyclohexadienyl)-3-buten-2-one were efficiently synthesized by alkylation of 2,4,4-trimethyl-3-(phenylsulfonylmethyl)-2-cyclohexen-1-ol and 1-(phenylsulfonylmethyl)-2,6,6-trimethyl-1,3-cyclohexadiene with propylene oxide followed by oxidation and elimination of sulfonyl group, respectively.
Synthesis of 4-(d-Alanylamino)-2-amino-2,4-dideoxy-d-xylose
Authors: Khan Hassan Akhtar , Hashimoto Hironobu , Yoshimura Juji
Published: July 2006

A prumycin diastereomer having d-configuration, 4-(d-alanylamino)-2-amino-2,4-dideoxy-d-xylose, was first synthesized from l-arabinose via benzyl 2,3-anhydro-4-azido-α-d-lyxopyranoside.
Formation of 5-Phenyltetrazole from N2-Benzoyl-N4-(phenylsulfonyl)benzohydrazide Hydrazone
Authors: Ito Suketaka , Tanaka Yumo , Kakehi Akikazu , Kawahata Mikio
Published: July 2006

5-Phenyltetrazole is obtained in a moderate yield by the mercury(II) oxide oxidation of the title hydrazidine prepared from N-(phenylsulfonyl)benzohydrazonoyl chloride and benzohydrazide. The tetrazole formation is interpreted in terms of an intramolecular SN2 type process of the intermediate formazan with the removal of benzenesulfinic acid. In the absence of oxidizing agents, the hydrazidine gives 2,5-diphenyl-1,3,4-oxadiazole and 3,5-diphenyl-4-phenylsulfonylamino-4H-1,2,4-triazole.
A Molecular Orbital Study of the Partial Reactivity of the Hydrogen of Aliphatic Compounds in the Hydrogen-abstraction Reaction by the Hydroxyl Radical
Authors: Shinohara Hiroyuki , Imamura Akira , Masuda Takahiro , Kondo Masaharu
Published: July 2006

The energy required to stretch a C–H bond of alkanes by 0.5 Å from an equilibrium bond length was calculated by the INDO method, and it was found that this energy has a relation with the delocalizability, DrR, of hydrogen atoms in alkanes, and with the activation energy for the hydrogen-abstraction reaction of the methyl radical from alkanes. The reactivities of hydrogen atoms in aliphatic alcohols and carboxylate ions, as defined by this energy were found to correlate with the partial reactivities of hydrogen atoms, just as was proposed by Anbar et al., i.e., the rate constants for the hydrogen-abstraction reaction of aliphatic compounds with hydroxyl radicals can be well explained by a summation of the partial reactivities assigned to primary, secondary, and tertiary hydrogen atoms bound to α- or β- (for γ-CH and δ-CH the same value as for β-CH was used) carbon atoms.
Study of the Chemisorption and Hydrogenation of Propylene on Platinum by Temperature-Programmed Desorption
Authors: Tsuchiya Susumu , Nakamura Masami , Yoshioka Norihiko
Published: July 2006

The temperature-programmed desorption (TPD) chromatograms of propylene from platinum black comprised four peaks: A, B, C, and D, with peak maxima at about 260, 380, 570, and higher than 720 K respectively. Peaks A and B were identified as the mixtures of propylene and propane. Peaks C and D were methane formed from chemisorbed propylene by decomposition as the temperature was raised during the subsequent TPD. The reactivities of various types of chemisorbed hydrogen previously detected by TPD were also investigated with regard to the hydrogenation of propylene. Two types of chemisorbed hydrogen, presumed to be present on the surface in the form of hydrogen atoms chemisorbed on top of platinum atoms and in the bridge form of molecular hydrogen, were found to react with propylene.
The Crystal Structure of a Stable Benzocyclobutene. II. 2,7-Di-t-butyl-10,10,11,11-tetracyano-4,5,9,12-tetraphenyltetracyclo-[6.4.0.03,6 .09,12]dodeca-1(8),2,4,6-tetraene
Authors: Tsukada Harumichi , Shimanouchi Hirotaka , Sasada Yoshio
Published: July 2006

As the first step in the investigation of the reaction mechanism of a benzocyclobutene derivatives, the title compound has been determined by the X-ray diffraction method. The crystals are monoclinic; space group P21/n; a=28.117(3), b=11.148(1), c=13.167(1) Å, and β=97.26(1)°. The asymmetric unit contains one molecule of the title compound and acetonitrile. The structure was solved by the direct method and refined by the block-diagonal least-squares method to a final R factor of 0.088 for 5456 observed reflections. The molecular framework consists of a planar ten-membered ring from benzodicyclobutene and a slightly folded four-membered ring formed by the addition of tetracyanoethylene (TCNE). Calculation has been undertaken for the non-bonded interaction energy of possible modes of approach between benzodicyclobutene and TCNE. The results are in qualitative agreement with the folding of the four-membered ring.
Metachromasy. V. The Effect of the Chain Length of Polyphosphate on the Metachromatic Behavior of Crystal Violet and Trypaflavine with Emphasis on the Binding Curve and the Spectra of Bound Dyes
Authors: Takatsuki Mineo , Yamaoka Kiwamu
Published: July 2006

Absorption spectra of two metachromatic dyes, Crystal Violet, CV, and Trypaflavine, TF, were measured in the presence of three sodium polyphosphates, NaPP, of different chain lengths. The optical titrations of these systems were performed at the phosphate residue-to-dye ratios, P/D, between 0 : 1 and about 1 : 1, where isosbestic points are present in the absorption spectra. The apparent molar absorption coefficients of the two dyes in each system changed sigmoidally with the increase in P/D. The extended principal component analysis was applied to the observed spectra of each dye–NaPP system in order to determine both the equilibrium constant for the binding reaction between the dye and the polymer and the pure spectra of the bound dyes. An empirical parameter α was introduced into the expression for the equilibrium constant, K=[complex]/[free dye] [unoccupied binding site]α, to reproduce the sigmoidal titration curve (α>1). The amount of the bound CV and TF increased with the increase in the chain length of NaPP at a given P/D, although the pure spectra of those bound dyes were independent of the chain length for low P/D values. The binding behavior of those dyes for high P/D values was also discussed by comparing the previous data with the binding curves calculated in this work.
Bridges in Polynuclear Complexes. I. The Reaction and Reaction Products of μ(NH2,O2) Dicobalt Complexes with Nitrites
Authors: Kubo Shigekazu , Shibahara Takashi , Mori Masayasu
Published: July 2006

The IR spectroscopy of the μ-amido-μ-nitro complex, [(NH2,N02){Co(NH3)4}2]Cl4·2H2O obtained from normal and 18O-labeled [(NH2,O2){Co(NH3)4}2](NO3)4 has revealed that the O atom in the Co–N–O–Co chain comes from the O2 bridge of the starting complex, whereas the O atom attached to the N atom from outside the chain comes from the nitrite used in the bridge conversion, μO2→μNO2. A reaction mechanism involving N2O3 as the reacting species is proposed. The reaction of [(NH2,O2){Co(NH3)4}2]X3 with the nitrite in neutral solution gave a non-electrolytic μ-hyperoxo dicobalt complex, [(NH2,O2)Co2(NH3)4(NO2)4](I). Treatment of I with perchloric acid gave a triple-bridged complex, [(NH2,NO2,O2)Co2(NH3)4(NO2)2]+, which reproduces I when treated with sodium nitrite.
Dual Fluorescence and Excited-state Double Proton Transfer in the Dimer of 3,5-Dialkyl-4-hydroxybenzylidenemalononitrile
Authors: Itoh Michiya , Inoue Kenji , Kuzuhara Tomoko , Kusui Tomoko
Published: July 2006

Dual fluorescence of the dimer of 3,5-dialkyl-4-hydroxybenzylidenemalononitrile (HO-BMN) was investigated by steady-state and nanosecond fluorescence spectroscopies. The dimerization of the compounds in 3-methylpentane (MP) solution was confirmed by concentration dependence of absorption and fluorescence spectra at low temperature (<150 K). While the MP solutions of the compounds are almost non-fluorescent at room temperature, the dimer exhibits a short-lived fluorescence (τ=4–9 ns) at 450–520 nm and a long-lived fluorescence (τ=21–34 ns) at 490–550 nm. The short-lived fluorescence was ascribed to a sandwich type dimer (D*) with a center of symmetry. An orientational relaxation leading to the double proton transfer reaction seems to occur in the excited state of the dimer. The long-lived fluorescence in the dimer was tentatively ascribed to the excited species (T*) generated by the double proton transfer reaction in D*. The excited-state proton transfer is discussed in terms of the effect of deuterium substitution of a 4-hydroxyl hydrogen upon fluorescence lifetimes of the dimer.
The Solvent Extraction of Bivalent Metal Picrates by 15-Crown-5, 18-Crown-6, and Dibenzo-18-crown-6
Authors: Takeda Yasuyuki , Kat\={o} Hisanori
Published: July 2006

The overall extraction equilibrium constants (Kex) for the 1:1:2 complexes of 15-crown-5 (15C5), 18-crown-6 (18C6), and dibenzo-18-crown-6 (DB18C6) with several bivalent metal picrates between benzene and water have been determined at 25 °C. The Kex sequences of the bivalent metal ions with 15C5, 18C6, and DB18C6 are Pb2+>Sr2+>Ba2+>Ca2+, Pb2+>>Ba2+=Sr2+>Hg2+>Ca2+, and Pb2+>Hg2+>Sr2+>Ca2+ respectively. To clarify the role of the crown ether in the extraction process, the three constituent equilibria have been investigated: the stability and the extractability of the bivalent metal ion-crown ether complex, and the distribution coefficient of the crown ether. The extractability of the bivalent metal ion-crown ether complex about the same bivalent metal ion increases with increasing size of the crown ether, and appears to be dependent on the chemical nature of the bivalent metal ion trapped in the cavity of the crown ether.