bluuebunny/crossref_metadata_2025 huggingface dataset:
Triple Ion and Quadrupole Formations from Trialkylammonium Sulfonates and Nitrate in Protophobic Aprotic Solvents with Higher Dielectric Constants
Authors: Hojo Masashi , Miyauchi Yoshihiro , Imai Yoshihiko
Published: July 2006

The formation of symmetrical triple ions (2M++X−\ightleftarrowsM2X+, (K2); M++2X−\ightleftarrowsMX2−, (K3); K2=K3) and the quadrupole (M2X++X−\ightleftarrowsM2X2, (K4); MX2−+M+\ightleftarrowsM2X2, (K5); K4=K5), in addition to the ion pair formation (M++X−\ightleftarrowsMX, (K1)) from uni-univalent salts (MX) has been examined in acetonitrile (dielectric constant ε=35.95), benzonitrile (ε=25.2), nitrobenzene (ε=34.82), and nitromethane (ε=36.67) at 25° by means of conductometry. Tho molar conductivities (Λ) of tributylammonium methanesulfonate (n-Bu3NHCH3SO3) of (0.4–6.0) ×10−3M (1 M=1 mol dm−3) in benzonitrile were explained by the formation of triple ions (Ka1=8.4×104, Ka2=Ka3=5.5×105, corrected by the activity coefficients of ions) within ±0.85% relative error, assuming that ΛT=ΛO⁄3 (ΛT: the limiting molar conductivity of the triple ions; ΛO: that of the simiple ions). In nitrobenzene, however, the quadrupole formation must be invoked for the salt in the same concentration range (Ka1=1.38×105, Ka2=Ka3=4.75×107, Ka4=Ka5=8.5×102). The alternative formation constant of the quadrupole (2MX\ightleftarrowsM2X2, (K41)) was evaluated as Ka41=5.0 instead of Ka4. Triple ion formation was observed in acetonitrile and nitromethane, but not in an amphiprotic solvent, ethanol (ε=24.55). The tendency for triple ion formation or higher aggregate formations from trialkylammonium salts was found to decrease as follows: Cl−>CH3SO3−, Br−> TsO−, NO3−>I−, CF3SO3−> (ClO4−). The difference in the aggregate forming ability is discussed from the view point of basicity of the anions, the strength for a proton acceptor in hydrogen bonding, and the localization of electrons in the anion molecule.
Regio- and Facial-Selective Effects of Allylic Heteroatoms in 1,3-Dipolar Cycloaddition of a Nitrile Oxide
Authors: Inouye Yoshinobu , Mitsuya Morihiro , Tokuhisa Kenji , Kakisawa Hiroshi
Published: July 2006

The 1,3-dipolar cycloaddition of nitrile oxides to 2-X-bicyclo[2.2.2]oct-5-enes (X=O, NMe, S, SO2) were investigated together with acyclic and alicyclic analogues. The regioselectivity in an exo-attack was controlled by the heteroatom present at an allylic position —a remote attack was predominant in the cases of O and SO2 but a vicinal attack in those of NMe and S— and the results were rationalized from the electronic nature of the heteroatom, X. In an endo-attack, a remote attack was observed in every case and the dipole-dipole repulsion between X and the oxygen of the nitrile oxide was considered to be a predominant factor. The steric environment around the heteroatom controled the facial-selectivity.
Observation of Atomic Corrugation on Au(111) and Iodine on Pt(111) in Air
Authors: Sashikata Kenji , Honbo Hidetoshi , Furuya Nagakazu , Itaya Kingo
Published: July 2006

The STM images acquired in the constant current mode were found to resolve individual close-packed gold atoms on Au(111) and iodine atoms on Pt(111). Measurements were made in air on the facets formed on single crystal spheres. Single crystals were prepared by melting pure metal wires with a hydrogen–oxygen flame.
Template Synthesis and Crystal Structure of a Dilead(II) Complex of a Macrocycle with N4O2 Donor Set
Authors: Tadokoro Makoto , Sakiyama Hiroshi , Matsumoto Naohide , Okawa Hisashi , Kida Sigeo
Published: July 2006

A dilead(II) complex of a binucleating macrocycle formed by the condensation of two molecules of 2,6-diformyl-4-methylphenol and two molecules of 1,3-diaminopropane has been obtained by template reaction. The crystal structure of this complex was analyzed by single-crystal X-ray method.
The Structure of 4-Methoxy-ONN-azoxybezene and Oxygen Transfer Reaction of 4-Methoxyazoxybenzenes in Sulfuric Acid
Authors: Yamamoto Jiro , Yamashita Hiroshi , Miyagawa Hisato , Abe Toshio , Tsukihara Tomitake
Published: July 2006

The structure of 4-methoxy-ONN-azoxybenzene (1α) has been determined by X-ray analysis. In sulfuric acid 1α gave a rearrangement product 4-hydroxy-4′-methoxyazobenzene, together with 4-methoxyazobenzene and 4-methoxy-NNO-azoxybenzene.
Synthesis and Binding Properties of Ethylbipyridinio-Modified β-Cyclodextrin
Authors: Du Yi-qun , Nakamura Asao , Toda Fujio
Published: July 2006

Mono-6-deoxy-6-[4-(1-ethyl-4-pyridinio)-1-pyridinio]-β-cyclodextrin (3) was synthesized. The conformation and the binding properties of 3 with benzene derivatives were examined by induced circular dichroism (ICD) in aqueous solution. The conformation of 3 was confirmed to such equatorial inclusion as β-CDx capped by ethylviologen (C2V2+) group. Further, compound 3 showed stronger binding ability with these guests (1:1 complexes) compared with β-cyclodextrin (β-CDx).
Application of the SPE Method to Organic Electrochemistry-X. Behaviors of the Manganese Redox Couple Incorporated in Pt–Nafion and Their Mediatory Oxidation of Cinnamyl Alcohol to Cinnamaldehyde
Authors: Ogumi Zempachi , Mizoe Toshiyuki , Zhen Chen , Takehara Zen-ichiro
Published: July 2006

The electrochemical behavior of a manganese redox couple incorporated into an SPE (Solid Polymer Electrolyte) composite electrode using Nafion (Pt–Nafion) was examined as a mediator for electroorganic syntheses. The mediatory reaction of the redox couple was examined in the oxidation of cinnamyl alcohol. The oxidation proceeded smoothly and gave cinnamaldehyde in high selectivity; the current efficiency was as high as 85%. The dissolving-out of manganese from the SPE was suppressed by the addition of 0.025 mol dm−3 MnSO4 to the catholyte.
Femtosecond-Picosecond Laser Photolysis Studies on Photoreduction Process of Excited Benzophenone with N,N-Dimethylaniline in Acetonitrile Solution
Authors: Miyasaka Hiroshi , Morita Kazuhiro , Kamada Kenji , Mataga Noboru
Published: July 2006

Photoreduction processes of excited benzophenone (BP) by N,N-dimethylaniline (DMA) in acetonitrile solution were studied by means of picosecond-femtosecond laser photolysis and time resolved transient absorption spectroscopy as well as transient photoconductivity measurement. Proton transfer process in the triplet ion pair formed by electron transfer (ET) at encounter between 3BP* and DMA, competing with the ionic dissociation process was observed. It was clearly demonstrated that, in addition to the triplet ion pair, the ion pair produced by the excitation of the CT complex between BP and DMA formed in the ground state and that produced by ET reaction between 1BP* and DMA played important roles in the reaction processes of excited benzophenone. The behaviors of the three kinds of ion pairs were investigated in detail, leading to the elucidation of reaction mechanism of each ion pair. The reactivity characteristic of each kind of the ion pair and its relation to the structure of the ion pair were discussed.
Splitting of the 2nd d–d Band of trans-[CoCl2N4]X-Type Complexes Observed in the Solid State at 113 K
Authors: Tsuchimoto Masanobu , Kita Masakazu , Fujita Junnosuke
Published: July 2006

The electronic spectra of trans-[CoCl2(NH3)4]Cl and its analogues measured in the solid state at 113 K show four ligand field bands assignable to the Ia(1Ega← 1A1g), Ib(1A2g← 1A1g), IIa(1B2g← 1A1g), and IIb(1Egb← 1A1g) transitions in D4h approximation. The ligand field parameters obtained from the observed data are; eσ(N)=7400–8000 cm−1, eσ(Cl)=4500–5400 cm−1, eπ(Cl)=300–830 cm−1, and the Racah’s parameter C estimated with the assumption of C=4B is ca. 2000 cm−1. A nearly linear relationship is obtained between the eσ(Cl) and eπ(Cl) values; the stronger the coordination of Cl− to Co(III), the stronger the π interaction of Cl− with Co(III).
In Situ Observations of the Phase Transition among Cobalt(II) Dichloride Hydrates and Crystal Structures of the Tetra- and Hexahydrates
Authors: Waizumi Kenji , Masuda Hideki , Ohtaki Hitoshi , Tsukamoto Katsuo , Sunagawa Ichiro
Published: July 2006

Transformation among cobalt(II) dichloride hydrates in aqueous solutions was studied by the optical microscopic method. Although there are three hydrates (CoCl2·6H2O, CoCl2·4H2O, and CoCl2·2H2O) in the phase equilibrium diagram, the only solution mediated transformation between CoCl2·6H2O and CoCl2·2H2O could be observed under the present experimental conditions and it was confirmed that CoCl2·4H2O hardly formed compared with the other two hydrates. In order to investigate the reason why CoCl2·4H2O was hardly crystallized at the transformation from CoCl2·6H2O through CoCl2·2H2O and vice versa, the crystal structure of CoCl2·4H2O was investigated by the X-ray diffraction method. The structure of CoCl2·6H2O was reexamined because previously reported results had a relatively large R-factor. The crystal of CoCl2·4H2O is monoclinic, space group P21/a with a=11.548(1) Å, b=9.342(1) Å, c=6.056(1) Å, β=110.79(1)°, and Z=4. The complex has a slightly distorted octahedral geometry about Co2+ ion and two Cl− ions are located at the cis-position. The crystal of CoCl2·6H2O is monoclinic, space group C2/m with a=10.380(2) Å, b=7.048(1) Å, c=6.626(1) Å, β=122.01(1)°, and Z=2. The geometry around the cobalt ion is also octahedral with four water molecules and two chloride ions at the equatorial and the axial positions, respectively. The remaining two water molecules are linked to the two Cl− ions by hydrogen bonding. The difficulty of crystallization of CoCl2·4H2O crystals in solutions was explained in terms of the relatively unstable cis-dichloro structure of the [CoCl2(H2O)4] moiety and its crystal structure stabilized by hydrogen bonding network between the cis-form moieties.
Photo-Cycloaddition Reactions of 2-Pyrones
Authors: Somekawa Kenichi , Shimo Tetsuro , Yoshimura Hiroyuki , Suishu Takaaki
Published: July 2006

Sensitized photoreactions of two 2-pyrones with five unsaturated compounds were investigated. The reactions of 2-pyrones with electron-deficient ethylenes gave [4+2]cycloadducts (3) and [2+2]cycloadducts (4) across the C5–C6 double bonds in the 2-pyrones. On the other hand, reactions with an electron-donating ethylene, ethyl vinyl ether (2i), gave other kinds of [2+2]cycloadducts (5) and a [4+2]cycloadduct (6), site- and regio-selectively. These two kinds of reactions were inferred to start at the C-6 and C-4 positions of the 2-pyrones to give 3 or 4, and 5 or 6, respectively. The regioselectivity of 6 was opposite to that for a thermal [4+2]cycloadduct (7). The substituents on 2-pyrones also influenced the product-distribution and the triplet energy-level.
An ESR Study of Aromatic Olefin Radical Cations
Authors: Bonazzola Lydia , Michaut Jean-Pierre , Roncin Jacques , Misawa Hiroaki , Sakuragi Hirochika , Tokumaru Katsumi
Published: July 2006

γ-Irradiation of phenyl- and diphenylethenes in CFCl3 matrix at 77 K resulted in the formation of the substrate radical cations. 1,1-Diphenyl-2-methylpropene radical cations exhibit a spin density (ρ=0.45) at the β carbon much higher than those of stilbene and 2-styrylnaphthalene radical cations and comparable to those of styrene and α-methylstyrene radical cations. The spin density at the vinyl carbons appears to play an important role in governing the reactivity of the olefin radical cations with molecular oxygen.
Preparation of New Nitrogen-Bridged Heterocycles. 25. A Smooth Synthesis of [1,4]Thiazino[3,4,5-cd]indolizine Derivatives
Authors: Kakehi Akikazu , Ito Suketaka , Fujii Tsuneo , Sakurai Tosio , Urushido Kunio , Hatanaka Susumu , Mabuchi Toshiaki , Matsushita Shun-ichiro
Published: July 2006

The title compounds were prepared smoothly in moderate yields by the reactions of 3-(mercaptomethylene)-2(3H)-indolizinones with various alkylating agents such as bromoacetonitrile, bromoacetates, and phenacyl bromides in the presence of base. The structural assignments of these products were accomplished by their spectral inspections, and the structure for one compound was distinctly proven by its X-ray crystallography. In order to explain the regioselectivity in this reaction, a molecular orbital calculation (CNDO/2) was also performed using a model compound.
The Application of Diarylamine Compounds in Analytical Chemistry. 1 Fluorescence Reactions among 4-(4-Methyl-2-quinolyl)aminosalicylic Acid, Cobalt(II) and Hydrogen Peroxide, and the Fluorimetry of Cobalt(II) by Using Its Fluorescence Reaction
Authors: Mori Itsuo , Fujita Yoshikazu , Kato Keiji , Toyoda Minako , Akagi Masao
Published: July 2006

The fluorescence reactions among 4-(4-methyl-2-quinolyl)aminosalicylic acid (MQAS) as a diarylamine compound, hydrogen peroxide as an oxidizing agent, and various metal ions such as cobalt(II) were spectrolluorometrically investigated in the presence or in the absence of various surfactants. The MQAS–hydrogen peroxide solution in the presence of trimethylstearylammonium chloride (STAC) as a cationic surfactant was catalytically converted to a fluorescence product by the coexistence of trace amounts of cobalt(II), and its relative fluorescence intensity at 400 nm in the fluorescence reaction product was proportional to the cobalt(II) concentrations. Moreover, a highly selective and sensitive fluorimetric method for the determination of cobalt(II) using MQAS and hydrogen peroxide in the presence of STAC in basic media was proposed. The calibration graph was linear in the range of 0–45 ng cobalt(II) per 10 cm3 at an emission wavelength of 400 nm, with an excitation wavelength of 320 nm.
Solvent Effect on the Dissociation of Benzoic and Nitrobenzoic Acids in Acetonitrile–Water Mixtures at 298 K
Authors: Niazi M S K , Ali J
Published: July 2006

The thermodynamic dissociation constants and the limiting molar conductivities of 2-, 3-, and 4-nitrobenzoic and benzoic acids have been determined in water–acetonitrile mixtures at 298 K. It is found that the acids dissociate in the dereasing order as 2-nitrobenzoic acid > 3-nitrobenzoic acid≈4-nitrobenzoic acid > benzoic acid. The conductance–concentration data were analyzed with the Lee and Wheaton equation. The present results are compared with the previous ones for these acids in alcohol–water system, and are interpretted in terms of solute–solvent interactions, intramolecular hydrogen bondings, resonance and inductive effects along with the substituent position.
Structural, Magnetic and Spectroscopic Characterization of Novel Di-μ-carboxylato-Bridged Binuclear Copper(II) Complexes with 1,10-Phenanthroline
Authors: Tokii Tadashi , Watanabe Naofumi , Nakashima Michio , Muto Yoneichiro , Morooka Mitsuo , Ohba Shigeru , Saito Yoshihiko
Published: July 2006

Bis(μ-carboxylato-O,O′)-diaquabis(1,10-phenanthroline)dicopper(II) dinitrate tetrahydrates, [Cu(RCOO)(phen)(H2O)]2(NO3)2·4H2O, where R=H, CH3, and (CH3)3C, were prepared and characterized by elemental analyses, electronic spectra, magnetic susceptibilities, and X-ray structure analysis. The magnetic susceptibility data conform to the usual dimer equation. The −2J values are 125 cm−1 for formate, 86 cm−1 for acetate, and 99 cm−1 for 2,2-dimethylpropanoate. The crystal structures of [Cu(HCOO)(phen)(H2O)]2(NO3)2·4H2O (1) and [Cu(CH3COO)(phen)(H2O)]2(NO3)2·4H2O (2) were determined by the single-crystal X-ray diffraction method. The crystallographic data are: Compound 1, monoclinic, I2⁄a, a=18.850(2), b=9.775(2), c=17.752(2) Å, β=99.03(1)°, V=3230.4(8) Å3, Z=4, R=0.055 for 2511 observed unique reflections; Compound 2, monoclinic, C2⁄c, a=18.563(4), b=14.272(5), c=14.126(3) Å, β=106.72(2)°, V=3584(2) Å3, Z=4, R=0.082 for 2092 reflections. The complexes consist of dimeric [Cu(RCOO)(phen)(H2O)]22+)] cations with five-coordinated copper ions linked by two carboxylato ions in a syn-syn bridging arrangement. The Cu···Cu distances are 3.103(2) Å for 1 and 3.063(3) Å for 2.
Synthesis, Ion-Exchange Properties, and Analytical Applications of Anilinium Zirconium(IV) Phosphate
Authors: Singh Dhruv Kumar , Mehrotra Pallavi
Published: July 2006

A new inorganic ion exchanger, anilinium zirconium(IV) phosphate (AZP), has been prepared under varying conditions. The effects of mixing ratio of reagents and the pH of the mixture on the ion-exchange properties of the material have been studied. The detailed studies, such as ion-exchange capacity, chemical and thermal stabilities, chemical composition, pH titration, and IR analysis were made. Distribution coefficients of metal ions have been studied in water, nitric acid, 1,4-dioxane, aqueous ammonium nitrate, thiourea–nitric acid, and thiourea–hydrochloric acid media. Some analytically important separations of metal ions have been achieved on the small columns of AZP.
Partial Molar Volumes of Sodium Perfluoroalkanoates and Lithium Perfluoro-1-alkanesulfonates in Aqueous Solutions
Authors: Tamaki Kunio , Watanabe Sumiko , Daikyoji Yuichi
Published: July 2006

The densities of aqueous solutions of sodium perfluoroalkanoates, F(CF2)nCOONa (n=1–4, 6, 7) and lithium perfluoro-1-alkanesulfonates, F(CF2)nSO3Li (n=1, 4, 8) were measured at 25°C, and the limiting partial molar volumes were calculated. The assignment of group partial molar volumes is discussed.
A Method for Measuring Surface Area of Carbon of Carbon-Coated Silica Gel
Authors: Kamegawa Katsumi , Yoshida Hisayoshi
Published: July 2006

An adsorption method for determining the surface area of only the carbon of carbon-coated silica gel has been developed. In this method p-nitrophenol (PNP) was used as an adsorbate owing to its selective adsorbability on a carbon surface. This method was applied to carbon-coated silica gel prepared by a CVD method to determine the surface area of the carbon.
Vacuum Sublimation Behavior of Nickel(II), Palladium(II), and Platinum(II) Chelates with Dimethylglyoxime
Authors: Suzuki Itaru , Honjo Takaharu , Terada Kikuo
Published: July 2006

A sublimation apparatus in perpendicular style with a continuous-temperature gradient (30–200 °C) along the glass tube (15–0 cm) at 10−2 Torr (1 Torr=133.322 Pa) was used.

Dimethylglyoxime (DMG) and its chelates of nickel(II) and palladium(II) in milligram amounts were sublimed without any thermal decomposition, while platinum(II) chelate was accompanied by a remarkable thermal decomposition during the sublimation process. All metal chelates, Ni(DMG)2 (brick-red), Pd(DMG)2(yellow), and Pt(DMG)2 (grayish violet), form needle-like crystals after purification with a sublimator under low pressure.
The Reactions of Optically Pure Menthyloxymethylphenylphosphine-Borane with Organolithium Reagents
Authors: Oshiki Toshiyuki , Imamoto Tsuneo
Published: July 2006

The reactions of (Rp)-menthyloxymethyl-phenylphosphine-borane with several organolithium reagents are described. Less sterically hindered reagents such as m-anisyllithium and p-anisyllithium react with the phosphine-borane to afford the corresponding substitution products with high stereochemical integrity with inversion of configuration. On the other hand, o-substituted phenyllithiums lead to products possessing very low optical purities.
New Applications of Crown Ethers. X. 13C NMR Relaxation Times Study of Cation-Binding Behavior of Monoazacrown Ethers and Bis(monoazacrown ether)s
Authors: He Gong-Xin , Imato Toshihiko , Ishibashi Nobuhiko , Shinkai Seiji , Matsuda Tsutomu
Published: July 2006

13C NMR relaxation times (T1s) have been determined for monoazacrown ethers (CA15C5 and CA18C6) and bis(monoazacrown ether)s (BCA15C5, BCA18C6, BOA15C5, and BOA18C6) in the absence and presence of Na+and K+ ions. For the monoazacrown ethers with heptyl side chain and the bis(monoazacrown ether)s with pentamethylene bridge chain marked changes in T1 values are observed upon the complexation, and the changes are dependent on the cation and on the structure of the ligands. The complexation with Na+ ion can give a larger effect on the T1 values for the bis(monoazacrown ether)s of 15- and 18-membered rings, especially on the mobility of the bridging chain carbons, which is indicative of the formation of an intramolecular sandwich complex. On the other hand, the present T1 study again shows the prominent effect of the oxygen in the bridging chain on the complexation of BOA15C5 and BOA18C6. Small differences in T1 values obtained between Na+ complexes and K+ complexes of these two bis(crown ether)s suggest that the complexes take an analogous partial structure for the two cations.
Interaction of α-Helical Glycopeptides with Lipid Bilayer Membrane
Authors: Otoda Kazuya , Kimura Shunsaku , Imanishi Yukio
Published: July 2006

α-Helical polypeptides having a glyco moiety at one end and a fluorescent probe at the other were prepared and investigated on the interaction with a lipid bilayer membrane. A glycopeptide composed of poly(alanine) and maltose was incorporated into the lipid membrane with the glyco moiety exposed to the aqueous phase and the peptide chain buried in membrane above the phase-transition temperature of the lipid membrane. However, below the phase-transition temperature, the glycopeptide induced the aggregation of dimyristoylphosphatidylcholine (DMPC) small unilamellar vesicles (SUV). Another glycopeptide composed of poly(γ-benzyl glutamate) and glucose also induced the aggregation of DMPC SUV, indicating that such the hydrophobic peptide tends to disturb the membrane structure significantly upon binding. The arrangement of the glycopeptide in a membrane was investigated by using a fluorescent probe connected to the end of the peptide chain. The terminal region of the peptide chain was located at the hydrophobic core of lipid membrane. However, the glycopeptide composed of 25 Ala residues had a smaller fraction taking perpendicular orientation to the membrane than that composed of 15 Ala residues. It was therefore considered that a part of the former glycopeptide molecules exits on the membrane surface, forming aggregates.
The Dependence on Alkyl Chain Length of 1H NMR Spectra of Surfactant Micelles with Aromatic Solubilizate
Authors: Hoshino Takashi , Imamura Yoshio
Published: July 2006

The splitting of methylene peaks in the 1H NMR spectra of surfactants of various alkyl length was studied in aqueous solutions solubilized with aromatic compounds, as a function of the carbon numbers of alkyls. In these spectra the methylene signals of long alkyls split into doublets. The location of the solubilization site is discussed while comparing the results with previous 1H NMR observations of long-alkyl-substituted molecules in aromatic solvents.
Hydroalumination and Related Reactions of Phenyl 1-(Trimethylsilyl)propadienyl Sulfide Followed by Quenching with Carbonyl Compounds
Authors: Tanaka Junji , Kanemasa Shuji , Tsuge Otohiko
Published: July 2006

Phenyl 1-(trimethylsilyl)propadienyl sulfide undergoes a hydroalumination with diisobutylaluminum hydride (DIBAH) or lithium butyl(diisobutyl)aluminum hydride (BL-DIBAH). The adduct anion derived from DIBAH is regioselectively trapped with carbonyl compounds at the position α to the phenylthio moiety to give 1,3-dienes as Peterson olefination products; the anion derived from BL-DIBAH is trapped at the position γ to the phenylthio moiety to give 3-buten-1-ols. Silylmetalation and stanylalumination on the same acceptor have been also briefly investigated as equivalent reactions.
The Moderation and Tunneling Reaction of Recoil T Atoms in Solid Xenon–Hydrogen Mixtures at 77 K
Authors: Fujitani Yoshiteru , Miyazaki Tetsuo , Fueki Kenji , Masaki Nobuyuki M , Aratono Yasuyuki , Saeki Masakatsu , Tachikawa Enzo
Published: July 2006

Recoil T atom reactions were studied in Xe–H2–D2 mixtures at 77 K. The isotope effect on the T-atom reaction with H2 and D2 (k(T+H2→HT+H)/k(T+D2→DT+D)) was measured on the basis of the HT and DT yields. The isotope effect (k(T+H2)/k(T+D2)) is 1.1 in the range of hydrogen concentrations of 0.1–1.0 mol%. Since the small isotope effect (1.1)is similar to the isotope effect (1.0) for a hot T-atom reaction in the gas phase, recoil T atoms are not thermalized at these concentrations in solid xenon and form HT and DT by means of hot-atom reactions. At concentrations of hydrogen of less than 0.1 mol%, the recoil T atoms are thermalized before they encounter the solute hydrogen. The isotope effect increases with a decrease in the hydrogen concentration and amounts to 3.1 at a hydrogen concentration of 0.01 mol%. Since a large isotope effect is expected for the tunneling reaction of T atoms, the large isotope effect (3.1) at 0.01 mol% hydrogen was interpreted in terms of the tunneling reaction of thermalized T atoms. The present results in the solid xenon–hydrogen mixtures were compared with those in the gaseous xenon–hydrogen mixtures reported previously. It was concluded that hot T atoms in the solid xenon at 77 K are deactivated much less effectively than in the gas phase and that they migrate long distances with excess kinetic energies.
Polarized Raman and Infrared Spectra of 1,2,3- and 1,3,5-Trichloro- and Tribromobenzenes
Authors: Sakamoto Hironobu , Yoshikai Kazumasa , Maruyama Takao , Nibu Yoshinori , Shimada Hiroko , Shimada Ryoichi
Published: July 2006

Assignment of the normal vibrations of 1,2,3- and 1,3,5-trichloro- and tribromobenzenes was made through the vibrational analyses of the polarized Raman and infrared spectra and also through the normal coordinate calculation. Substitutional effect on the vibrational frequencies and modes of the hydrogen bending and wagging vibrations induced by the halogen atoms is discussed.
The Square Planar-Octahedral Equilibrium of Bismacrocyclic Ni(II)Ni(II) and Cu(II)Ni(II) Complexes with Polymethylene Bridges of Various Lengths
Authors: Mochizuki Katsura , Iijima Asako , Endoh Yumiko , Ikeda Yoshihito
Published: July 2006

Bismacrocyclic Ni(II)Ni(II) and Cu(II)Ni(II) complexes, i.e., 7,7′-polymethylenebis[2,12-dimethyl-3,7,11,17-tetraazabicyclo[1 1.3.1]heptadeca-1(17),2,11,13,15-pentaene]dinickel(II) perchlorates and 7,7′-polymethylenebis[2,12-dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-l(17),2,11,13,15-pentaene]copper(II)nickel(II) perchlorates with polymethylene bridges 2–6-C long, were found to exist in an equilibrium between square planar and octahedral Ni(II) ions in water. The equilibrium constants and the thermodynamic parameters, ΔH and ΔS, for the Cu(II)Ni(II) complexes were evaluated on the basis of the analyses of the temperature-dependent absorption spectra. The formation of octahedral species was found to be exothermic; this reflects the predominant contribution of an exothermic change to the formation of Ni(II)–water bonds. The absolute values of ΔS corresponding to those expected for the liberation of two molecules of water are not in conflict with the equilibrium proposed. For both the Ni(II)Ni(II) and Cu(II)Ni(II) complexes, the equilibrium shifts toward the octahedral side as the polymethylene bridge is shortened.
Addition of a Sulfonamidyl Radical to Unsaturated Aromatic and Aliphatic Hydrocarbons
Authors: Miura Yozo , Ohnishi Tetsuya , Kinoshita Masayoshi , Kinoshita Takamasa
Published: July 2006

The reaction of Nphenylsulfonyl-3,5-di-t-butylphenylaminyl radical (2) with unsaturated aromatic and aliphatic hydrocarbons has been carried out in degassed benzene at 75°C. The reactions of 2 with unsaturated aromatic hydrocarbons gave 1:1, 1:2, and 2:1 adducts of 2 and the hydrocarbons in fair to good yields. On the other hand, in the reactions of 2 with unsaturated aliphatic hydrocarbons, hydrogen-abstraction by 2 from the hydrocarbons was the major reaction. In the reaction with 2-methylpropene, a product indicating the addition of 2 to 2-methylpropene was isolated in a 16% yield. On the basis of these results the reactivity of 2 is discussed and compared with that of structurally related N(4-chlorophenylthio)-3,5-di-t-butylphenylaminyl radical.
A Cyclopropane Sliding Reaction of Δ3-Africen-10-yl Cation
Authors: Hayano Kiyoharu , Shirahama Haruhisa , Matsumoto Takeshi
Published: July 2006

Rearrangement of Δ3-africen-10-yl cation, generated by the treatment of 10β-chloro-Δ3-africene with silica gel, accompanied cyclopropane sliding.
Molecular Complex of a Cationic Porphyrin and p-Nitrophenol. Verification of the Porphyrin Dimerization
Authors: Kano Koji , Hashimoto Shizunobu
Published: July 2006

Complexation between 4,4′,4″,4'″-(21H,23H-porphine-5,10,15,20-tetrayl)tetrakis[1-methylpyridinium] chloride (TMPyP) and p-nitrophenol has been studied in water. Upon the addition of p-nitrophenol, the coalesced fluorescence Q bands of TMPyP are resolved into well-separated Q(0–0) and Q(0–1) bands and the fluorescence decay comes to involve two exponential components. These results can be explained by the dimer model of TMPyP.
Bis(ferrocenecarbothioyl) Sulfide. Synthesis and Characterization
Authors: Kato Shinzi , Fukushima Tetsuaki , Ishihara Hideharu , Murai Toshiaki
Published: July 2006

Bis(ferrocenecarbothioyl) sulfide 1 was synthesized and characterized. The sulfide 1 was found to serve as an efficient ferrocenecarbothioylating reagent for amines, alcoholates, thiolates, and selenolates.
XPS Study of Bis(1,2-diaryl-1,2-ethylenedithiolato)nickels
Authors: Shiozaki Hisayoshi , Nakazumi Hiroyuki , Morikawa Tsutomu , Sato Yukihiro , Kitao Teijiro
Published: July 2006

The binding energies of S 2p and Ni 2p of the bis(1,2-diaryl-1,2-ethylenedithiolato)nickels were measured by means of X-ray photoelectron spectroscopy using a silicone oil as a reference. The results indicated that a reasonable correlation exists between Hammett substituent constants σp on phenyl group in the nickel complexes and the binding energy and between charge of complexes and the binding energy.
Synthesis of Several New Pyridazines and 3,5-Diarylanilines
Authors: Sadek Kamal Usef , Selim Maghraby Ali , Abdel-Motaleb Ramadan Maawad
Published: July 2006

Several new pyridazines and 3,5-diarylanilines were obtained from (1-arylethylidene)malononitriles 1b–e as starting compounds.
Divalent Metal Ion-Mediated Phosphodiester Bond Formation from Adenosine-5′-phosphorimidazolide with Glycolic Acid or Lactic Acid in Aqueous Solution. A Nonenzymatic Model Reaction for Nucleotidyl Transfer
Authors: Sawai Hiroaki
Published: July 2006

Some divalent metal ions mediated in phosphodiester bond formation from adenosione-5′-phosphorimidazolide (ImpA) and glycolic acid or lactic acid giving glycolyl adenylate or lactyl adenylate. The effect of divalent metal ions on this reaction was in the order: Pb2+>Ni2+>Co2+>Zn2+>Cu2+>Mn2+>Ca2+>Mg2+>none>Hg2+. The metal ions promoted the reaction orienting the substrates and increasing the nucleophilicity of the hydroxy group of α-hydroxy acid by coordination. On the other hand, very little or no phosphodiester bond formation took place from ImpA and 3-hydroxypropionic acid or 4-hydroxybutyric acid in the presence of metal ions.
A Time-Resolved Photoacoustic Method with Pulsed Laser Excitation in the Condensed Phase: The Relation between Signal Intensity and Decay-Rate Constant
Authors: Terazima Masahide , Azumi Tohru
Published: July 2006

The photoacoustic signal magnitude in the condensed phase with a piezoelectric transducer and a pulsed laser is theoretically calculated for various quantum yield of the triplet formation (φisc) and decay rate constants from the triplet state. The results show that the φisc value and the triplet lifetime can be determined from the PA signal intensity.
Magnetic Properties of Molybdenum(IV) Trinuclear Coordination Compounds, Ba[Mo3O3S(Hnta)3]·10H2O and Cai1.5[Mo3S4(Hnta)2(nta)]·12H2O
Authors: Kobayashi Hanako , Shibahara Takashi , Uryû Norikiyo
Published: July 2006

The magnetic susceptibilities of two molybdenum(IV) trinuclear coordination compounds with cores [Mo3(μ3-S)(μ-O)3] and [Mo3(μ3-S)(μ-S)3] were measured in the temperature region from liquid He to room temperature. They had some extra diamagnetic susceptibilities in addition to the calculated values which have been discussed in anticipation of mesoscopic electronic devices.
Homocoupling of Aryl Halides Using Nickel(II) Complex and Zinc in the Presence of Et4NI. An Efficient Method for the Synthesis of Biaryls and Bipyridines
Authors: Iyoda Masahiko , Otsuka Hiroki , Sato Koichi , Nisato Nobue , Oda Masaji
Published: July 2006

Reduction of NiX2(PPh3)2 with zinc in the presence of Et4NI gives a nickel catalyst which has been proven to be useful for the coupling of aryl halides. This nickel catalyst can be prepared in THF without an additional triphenylphosphine and is effective for the homocoupling of aryl chlorides, bromides, and iodides to produce biaryls and bipyridines in good yields. The reported new approach provides a simple access to novel derivatives of biaryls and bipyridines.
η3-Allyl(methyl)platinum(II) Complexes. Synthesis, Conversion into η1-Allyl Complexes, and Electrochemical Behavior in Comparison with Thermolysis
Authors: Suzuki Takeshi , Ueda Michihisa , Koumoto Ryuhei , Nakamura Yukio
Published: July 2006

Complexes of the type [Pt(η3-allyl)Me(L)] (1) (allyl=C3H5, 1-MeC3H4, or 2-MeC3H4; L=tertiary phosphine) as well as [Pt(η3-C3H5)Bu(PPh3)] have been synthesized and characterized by NMR (1H, 13C) and mass spectroscopy. By the reaction with bidentate tertiary phosphines (L–L), [Pt(η3-C3H5)Me(PPh3)] (1b) was converted into η1-allyl complexes of the type [Pt(η1-C3H5)Me(L–L)]. With PPh3, cis-[Pt(η1-C3H5)Me(PPh3)2] was isolated. The reaction of 1b with neat 2,4-pentanedione (Hacac) afforded [Pt(acac)Me(PPh3)]. Complexes 1 thermally decompose in the solid state and in diphenylmethane solely giving propylene and methane, but the allyl-alkyl coupling reaction to form 1-butene is promoted by the addition of maleic anhydride. A similar coupling-promoting effect was observed in the electrochemical oxidation of 1b in THF at 23°C without additive. By taking into account the one-electron oxidation and the participation of the PPh3 ligand in its oxidation process, a possible mechanism of this electrochemically promoted coupling is proposed.
NAD (P)+-NAD (P)H Models. 69. Mechanism of Stereospecific (NET) Hydride Transfer Controlled by Electronic Effect
Authors: Ohno Atsuyoshi , Ogawa Masahiko , Mikata Yuji , Goto Mutsuo
Published: July 2006

The enantiotopic C4-hydrogen in Me3MQPH is abstracted stereospecifically by certain oxidizing reagent such as metal ions and quinones. The stereospecificity depends on the reactivity of the oxidizing reagent. Namely, in the oxidation with Fe(III) or Co(III) ion, a Brønsted-like correlation is observed between the specificity and pKa of amine added to the reaction system, whereas the stereospecificity of the oxidation with quinones is not affected by amine. The mechanism of this electronically controlled stereospecificity is discussed.
Reaction of Trimethylsilyl Isoselenocyanate with Oxiranes and Oxetane
Authors: Sukata Kazuaki
Published: July 2006

The reaction of trimethylsilyl isoselenocyanate with oxiranes and oxetane gave 2-trimethylsiloxyalkyl selenocyanates and 3-trimethylsiloxypropyl selenocyanate, respectively, in good to excellent yields. Effects of solvents and catalysts on regioselectivity were examined.
Peparation of New Nitrogen-bridged Heterocycles. 21. A Facile Synthesis of 2-Indolizinethiols Using New Protecting Groups
Authors: Kakehi Akikazu , Ito Suketaka , Yamada Naoaki , Yamaguchi Kiminobu
Published: July 2006

Some indolizine derivatives having (2-cyanoethyl)thio or (2-ethoxycarbonylethyl)thio group at the 2-position were prepared in moderate to good yields starting from the corresponding pyridinium 1-(thiocarbonyl)methylides. The treatment of these indolizines with a strong base such as potassium t-butoxide in N,N-dimethylformamide (DMF) gave smoothly title compounds, 2-indolizinethiols, with the elimination of acrylonitrile or ethyl acrylate.
Intermediates Formed in the Reaction of Benzenethiol or t-Butylthiobenzene with Ethyl Benzoylacetate in Polyphosphoric Acid
Authors: Nakazumi Hiroyuki , Watanabe Shigeru , Kitaguchi Tohru , Kitao Teijiro
Published: July 2006

The reaction of benzenethiol with ethyl benzoylacetate in polyphosphoric acid (PPA) at low temperature gave mainly ethyl 3-phenyl-3,3-bis(phenylthio)propionate 8 as an intermediate in the synthesis of thioflavones, while that from t-butylthiobenzene under similar conditions gave ethyl 3-(phenylthio)cinnamate 7 as a major product and many by-products. The reaction constant for intramolecular cyclic condensation of 7 in 98% sulfuric acid was −0.46 and −0.54 using Hammett substituent constants, σm and σm+, respectively. It is suggested that the increase of electron density at the ring closure site of the benzenethiol moiety of 7 promotes this ring closure reaction.
Thermal Decompositions of CH3I and CD3I. Experimental and Theoretical Approaches to the Specific Rates at the High Pressure Limit
Authors: Kodama Sukeya , Ooi Yasuhiro
Published: July 2006

The rate constants on the thermal decompositions of CH3I and CD3I at the high pressure limit, kd∞, were evaluated from the decomposition rates, measured as functions of the reaction time and the pressure of methyl iodide. The values of kd∞(CH3I) at 606.8, 620.2, 633.5, and 649.5 K were 2.92, 8.22, 22.0, and 68.2×10−6 s−1, respectively. The values of kd∞(CD3I)/kd∞(CH3I) were 0.290 at 620.2 K, 0.285 at 633.5 K, and 0.279 at 649.5 K. Meanwhile, the calculations for kd∞ were carried out using a rate theory derived from the assumption that the zero point energy and the vibrational energy are concerned in the entropy term of kd∞. From good correspondence between the experimental and calculated values, the values of D0 (chemical bond dissociation energy)=243.7, ΔE0 (energy change at 0 K)=230.6, and ΔH298° (enthalpy change at 298 K)=236.3 kJ mol−1 were obtained for the CH3–I bond dissociation. On the decomposition of equimolar mixture of CH3I and CD3I at 633.5 K and 10.67 kPa of the total pressure, it was found that the initial rate ratio of R^°(CH4+CH3D)/R°(CD4+CD3H) is 1.94 and the excitations to the active molecules of CH3I and CD3I in the mixture are less effective than those in the separated systems of CH3I and CD3, respectively.
Liquid Crystalline Properties of Alkyl 4-[4-(4-Methoxybenzoyloxy)benzylideneamino]benzoates and 4-[4-(4-Methoxybenzylideneamino)benzoyloxy]benzoates
Authors: Matsunaga Yoshio , Matsuzaki Hiroyuki , Miyajima Nobuhiko
Published: July 2006

The mesomorphic properties of homologous series of alkyl 4-[4-(4-methoxybenzoyloxy)benzylideneamino]benzoates and the isomeric compounds, 4-[4-(4-methoxybenzylideneamino)benzoyloxy]benzoates have been studied, employing thirty ester alkyl groups. The nematic phase appearing in the former series is thermally more stable than that in the latter: even the t-butyl and 1,1-dimethylpropyl esters are nematogenic. The mesophases in these esters are significantly promoted relative to those in the isopropyl and 1-methylpropyl esters, respectively. An alternation in the thermal stability of the nematic phase occurs when the branching methyl group is moved progressively to the penultimate carbon of the chain in both series. In the second series, the stabilization of the smectic A phase by 3- or 4-methylation is observed for both butyl and pentyl esters.
Some Mechanochemical Considerations on the Numbers of Spins Induced by Ultraviolet Light
Authors: Kashiwagi Hiroshi , Inoue Masami
Published: July 2006

The number of spins/g (NOS) generated in a binary powder of glycolic acid and silica–alumina (SA) increased during ultraviolet (UV) irradiation. After stopping illumination, the NOS value was found to decrease up to a constant number of sping/g (CNS), which was remarkably greater than the NOS value obtained before UV irradiation. The CNS values, thus obtained, were influenced not only by the calcination temperature of SA (Tea) and by the atmosphere of storage, but also by the duration of UV irradiation (DI). The values of CNS obtained at a low Tca (below 400°C) were also influenced by the time interval between stopping shaking and the start of UV irradiation (ti). Values of NOS having attained CNS remained unchanged for a long period, but finally began to decrease. The duration of CNS (DCNS) was also affected by Tca, the atmosphere of storage, DI, and ti DCNS decreased when CNS increased, and became unchanged when CNS reached a constant value. Values of CNS and DCNS induced by UV light were also influenced by the size of SA particles and by the mechanical energy given by shaking or compressing. Such mechanochemical effects are available, at least for studying the generation mechanism of UV-induced surface activity, for an improvement of the reproducibility of physicochemical data obtained during or after UV irradiation, and for the method of obtaining materials of constant efficiency.
Stereochemical Control in Microbial Reduction. 12. (S)-4-Nitro-2-butanol as a Source to Synthesize Natural Products
Authors: Nakamura Kaoru , Kitayama Takashi , Inoue Yoshihiko , Ohno Atsuyoshi
Published: July 2006

(S)-(+)-4-Nitro-2-butanol (1) obtained by the stereoselective reduction of 4-nitro-2-butanone by bakers’ yeast was employed for the syntheses of natural products. A precursor of (+)-brefeldin A is synthesized starting from this chiral building block by 10 steps short-cut procedure compared with the shortest method so far reported. (S)-(+)-Sulcatol is obtained in much better enantiomeric purity than those reported. The reactivity of 1 in base-catalyzed condensations with Michael acceptors or aldehydes is largely affected by a base employed as the catalyst.
Effect of Charge Density on the Cooperative Binding Isotherm of Surfactant Ion to Polyelectrolyte
Authors: Satake Iwao , Takahashi Toshi , Hayakawa Katumitu , Maeda Tamaki , Aoyagi Makoto
Published: July 2006

The binding isotherm of dodecyltrimethylammonium ion to partially hydrolyzed poly(potassium vinyl sulfate) was determined potentiometrically as a function of the average separation (d) between neighboring ionic groups. The cooperativity in binding process was found to decrease rapidly to about d≈0.44 nm and eventually disappear at d≈3.7 nm.
Coordination Selectivity in the Fe(II) Complex with 8-Hydroxy-7-[(2-hydroxy-5-carboxyphenyl)azo]-5-quinolinesulfonic Acid
Authors: Bai Zhi-Ping , Einaga Hisahiko , Hidaka Jinsai
Published: July 2006

The coordination of the title ligand (hcqs) to Fe(II) has been studied on the basis of its electronic absorption spectral characteristics, equilibrium, and stopped-flow kinetics in comparison with those of the related ligands. The bifunctional hcqs coordinates to Fe(II) not with a quinolinol (O–N) moiety, but selectively with a dihydroxyazo (O–N–O) one. The reaction mechanism of hcqs with Fe(II) and the thermodynamic stability of the complex are also discussed.
Photochemical Reaction of 1,3-Diketones. Transformation of 2-Benzoyl-2-methylcyclohexanones to 4-Benzoyl-2-methylcyclohexanones
Authors: Hasegawa Tadashi , Nishimura Michiko , Kodama Yukio , Yoshioka Michikazu
Published: July 2006

Upon irradiation, 2-benzoyl-2-methylcyclohexanone gave 4-benzoyl-2-methylcyclohexanone via Type II cyclization and a subsequent ring opening in 79% yield, whereas 2-benzoylcyclohexanone gave only the Type II elimination product. 2-Benzoyl-2-methyl-1-tetralone also underwent phototransformation to 4-benzoyl-2-methyl-1-tetralone.
Halogenation Using Quaternary Ammonium Polyhalides. XXIV. Chlorination of Acetanilides with Benzyltrimethyl ammonium Tetrachloroiodate
Authors: Kajigaeshi Shoji , Shinmasu Yoichi , Fujisaki Shizuo , Kakinami Takaaki
Published: July 2006

The reactions of acetanilides with a calculated amount of benzyltrimethylammonium tetrachloroiodate in acetic acid at room temperature or at 70°C gave, selectively, the desired chloro-substituted acetanilides in good yields.
Chromatographic Optical Resolution on 3,5-Disubstituted Phenylcarbamates of Cellulose and Amylose
Authors: Okamoto Yoshio , Aburatani Ryo , Hatada Koichi
Published: July 2006

3,5-Difluorophenylcarbamates and 3,5-bis(trifluoromethyl)phenylcarbamates of cellulose and amylose were prepared and used as chiral stationary phases for high-performance liquid chromatography to resolve optical isomers. Their optical resolving abilities were compared with those of 3,5-dimethylphenylcarbamates and 3,5-dichlorophenylcarbamates of the polysaccharides. 3,5-Difluorophenylcarbamates afforded practically useful columns.
The Thermal Decomposition of Ammonium Zinc Trihydrogenbis(phosphate) Monohydrate (NH4)ZnH3(PO4)2·H2O
Authors: Takenaka Atsushi , Hieda Tsuyoshi , Kimura Koji , Motooka Itaru , Nariai Hiroyuki
Published: July 2006

(NH4)ZnH3(PO4)2·H2O[NZHP] was prepared by a wet method. NZHP was gradually decomposed to di-(P2) and oligophosphates (n=3–9: Poligo). A part of the formation of Poligo involved hydrolysis of the –P–O–P– linkages of P2, which was accerelated by humidity. γ-Zn2P2O7 partially crystallized from P2. Above 350°C, NZHP was changed to long-chain β-Zn(PO3)2.
Dehydrogenation of Hydroaromatic Components in Coal-Derived Hydrocarbons for Structural Analysis
Authors: Sugimoto Yoshikazu , Miki Yasuo , Oba Masaaki , Yamadaya Shoko
Published: July 2006

The dehydrogenation technique was evaluated by using several cyclic hydrocarbons, and was successfully used to convert hydroaromatic components in coal-derived nonpolar fractions into the corresponding aromatic compounds.
Ni(II) Complexes of N,N′-Ethylenebis(o-mercaptobenzamide): A Quadridentate Thiolato Amide {S2N2} Ligand
Authors: Yamamura Takeshi , Tadokoro Makoto , Nakamura Nobuhumi , Tanaka Koji , Asakura Kiyotaka
Published: July 2006

Three nickel(II) complexes with N,N′-ethylenebis(o-mercaptobenzamide), H4ebtsa, a quadridentate {S2N2} ligand classified as a PAC (polyanionic chelating) ligand, were isolated. Although they were different in their apparent charges, their coordination units were revealed to be equal from their physicochemical behavior. They will be described as Ni(H2ebtsa). EXAFS and XANES study was undertaken for one of the new compounds, and the results were compared with those for similar three NiS2N2 complexes, (N,N′-ethylenebis(o-mercaptobenzylidenaminato))Ni(II), (N,N′-ethylenebis(o-mercaptobenzylaminato))Ni(II) and (NEt4)[Ni(SPh)4]. From these results and a comparison with the results for [Ni(ebtsa)]2, it was concluded that a square planar {S2N2} unit was reliable as the coordination sphere of Ni(H2ebtsa). The character of the amide proton in the coordination unit was also studied.
The Effect of the Reactor Type on the Selectivity of Thermal Reactions of p-Xylene in Temperature Gradient Systems
Authors: Kawakami Shigenobu , Iwaki Shingo , Nakada Masahiro , Yamaguchi Tatsuaki
Published: July 2006

Thermal reactions of p-xylene were investigated in two kinds of reactors, batch type and flow type, with a large temperature gradient. Excellent differences of the resulting products were observed between these two types of reactors. As for a batch type reactor, 4,4′-dimethylbibenzyl was produced in a high yield with [2.2]paracyclophane and toluene as by-products, and as for a flow type reactor, toluene was obtained as a major product with a low selectivity of 4,4′-dimethylbibenzyl, respectively. These results were different from those of the conventional fast flow pyrolysis method in which [2.2]paracyclophane or poly(3,6-dimethylene-1,4-cyclohexadiene) was formed as a major product. These differences can be accounted for by the partial separation of a reaction mixture caused by the thermal diffusion effect, which arises when the mixture is subject to a temperature gradient.
Unambiguous Proof of Nitrile Formation from Pyrazine Skeleton through Photo-Oxidative Degradation. Isolation and Structural Determination of Photodegraded Product of Amorphous Poly(2,5-distyrylpyrazine)
Authors: Hashimoto Yukihiko , Adegawa Yutaka , Hasegawa Masaki , Onodera Kazuyuki , Sakuragi Hirochika , Tokumaru Katsumi
Published: July 2006

In the presence of oxygen, amorphous poly(2,5-distyrylpyrazine) film was readily photodegraded, accompanied by cleavage of the pyrazine rings in the main chain. From the photodegraded film, t-2,c-4-diphenylcyclobutane-r-1,t-3-dicarbonitrile was isolated in 13% yield.
Oxidation Using Quaternary Ammonium Polyhalides. IX. Oxidation of Hindered Phenols with Benzyltrimethylammonium Tribromide
Authors: Kajigaeshi Shoji , Morikawa Yukihiro , Fujisaki Shizuo , Kakinami Takaaki , Nishihira Keigo
Published: July 2006

Reactions of hidered phenols, such as 2,6-di-t-butyl-4-methylphenol, 3,5-di-t-butyl-4-hydroxybenzyl alcohol, and 2,6-di-t-butylphenol, with benzyltrimethylammonium tribromide were carried out in dichloromethane in the presence of water, t-butyl alcohol, or aqueous sodium hydroxide at room temperature. Sequential reaction processes were provided by the obtained products.