bluuebunny/crossref_metadata_2025 huggingface dataset:
Pressure Effects on the Hydrolysis of 3-Nitro-4-acyloxybenzoic Acids Catalyzed by Hexadecyltrimethylammonium Bromide Micelle
Authors: Makimoto Syoichi , Suzuki Keizo , Taniguchi Yoshihiro
Published: July 2006

The rates of the hydrolysis of 3-nitro-4-acetoxybenzoic acid (NABA), 3-nitro-4-propionyloxybenzoic acid (NPBA), 3-nitro-4-butyryloxybenzoic acid (NBBA), and 3-nitro-4-valeryloxybenzoic acid (NVBA), catalyzed by the hexadecyltrimethylammonium bromide (HTAB) micelle, were measured at pressures up to 2 kbar at 25 °C in Tris buffer solution (0.01 M, pH 8.7). The ester binding constant K increased and the rate constant of the hydrolysis catalyzed by micelle km decreased with longer alkyl chains of esters at 1 bar. The km values were separated into the contribution of kOH (hydroxide ion catalyzed hydrolysis) and kT (Tris catalyzed hydrolysis), which increased monotonically up to 2 kbar. On the other hand, the K values decreased and then inversed with minima at about 1.5 kbar except for that of NABA. From the pressure dependence of log K, the volume changes, ΔV, accompanying the ester binding to the HTAB micelle at 1 bar were estimated to be in the range of 11±2 cm3/mol for NABA to 23±2 cm3/mol for NVBA. The activation volumes for the hydrolysis catalyzed by micelle, were measured as −6±2 cm3/mol for ΔV*OH and −16±2 cm3/mol for ΔV*T for each ester. The activation volumes for the spontaneous hydrolysis were measured as −5±2 cm3/mol for ΔV*OH and −16±2 cm3/mol for ΔV*T for each ester. The reaction mechanism was discussed in terms of ΔV and ΔV*.
Synthesis of 5″-Deoxy-5″-fluorolividomycin B
Authors: Torii Takahiro , Tsuchiya Tsutomu , Umezawa Sumio , Umezawa Hamao
Published: July 2006

A masked lividomycin B derivative in which only the C-5″ hydroxyl group remains free has been prepared and treated with diethylaminosulfur trifluoride as the key step to give the title compound. A macrocyclic compound, that is, 2′,5″-carbamate was also obtained by the above reaction, and the structure was determined chemically and by the NMR-spectrum of its deblocked derivative.
A New Glycoside, Kusaginin Isolated from Clerodendron trichotomum
Authors: Sakurai Atsushi , Kato Takahiko
Published: July 2006

A new glycoside, kusaginin was isolated from Clerodendron trichotomum Thunb. and 2-(3,4-dihydroxyphenyl)ethyl 3-O-α-l-rhamnopyranosyl-4-O-(3,4-dihydroxycinnamoyl)-β-d-glucopyranoside was assigned to this substance from studies on the hydrolysis products and from analyses of the 1H NMR and 13C NMR spectra.
Studies on Aqueous Solutions of Saccharides. I. Activity Coefficients of Monosaccharides in Aqueous Solutions at 25 °C
Authors: Miyajima Koichiro , Sawada Masahiro , Nakagaki Masayuki
Published: July 2006

Activity coefficients of isomeric monosaccharides, d-glucose, d-mannose, and d-galactose were determined by isopiestic comparison method at 25 °C. Excess partial molar entropy of water (\barSwex) of each monosaccharide solution was negative and the absolute value increased with concentration of solute. From the magnitudes of negative \barSwex, it was concluded that the structure making ability among three isomers lies in the order d-glucose>d-mannose>d-galactose.
Synthesis and Epoxidation of trans-5,6-Diacetoxy-1-benzoyloxymethyl-1,3-cyclohexadiene
Authors: Ogawa Seiichiro , Toyokuni Tatsushi , Ara Masayasu , Suetsugu Masaru , Suami Tetsuo
Published: July 2006

The title substituted 1,3-cyclohexadiene was prepared in three steps from the readily available Dl-1,2-di-O-acetyl-(1,3/2)-3-bromomethyl-5-cyclohexene-1,2-diol. Epoxidation of it with m-chloroperoxybenzoic acid in 1,2-dichloroethane afforded several stereoisomers of the biologically interesting highly oxygenated cyclohexane derivatives.
Methylation of Deoxynucleotides with Trimethyl Phosphate in Aqueous Phase
Authors: Tanabe Toshizumi , Yamauchi Kiyoshi , Kinoshita Masayoshi
Published: July 2006

Action of trimethyl phosphate on thymidine 5′-phosphate, deoxycytidine 5′-phosphate, deoxyadenosine 5′-phosphate, and deoxyguanosine 5′-phosphate at 37–60 °C, and pH 7–10 gave their methyl esters and base-methylated derivatives. Esterification took place in all deoxyribonucleotides to the almost same extent and its rate was enhanced by the reaction temperature, while being independent of pH in the range 7–10. On the other hand, methylation of the base moieties was affected by both the reaction temperature and pH of the reaction medium. The reactivity order of the four kinds of base moieties w s; at pH 7, cytosine base (N-3)>guanine base (N-7)>adenine base (N-1)>>thymine base (N-3); at pH 10, thymine base (N-3)>guanine base (N-1>N-7)>cytosine base (N-3)>adenine base (N-1).
Potassium Fluoride on Alumina. An Efficient Solid Base for Elimination, Addition, and Condensation
Authors: Yamawaki Junko , Kawate Takehiko , Ando Takashi , Hanafusa Terukiyo
Published: July 2006

Alumina coated with potassium fluoride proved to be a versatile solid base for olefin- and acetylene-forming elimination, the Michael addition, aldol condensation, and the Darzens condensation.
Aryliminodimagnesium Reagents. III. The Deoxygenative Condensation with Nitroso- and Nitroarenes: Electronic Effect of Substituents on Product Distribution
Authors: Okubo Masao , Takahashi Tomoko , Koga K\={o}ji
Published: July 2006

Aryliminodimagnesium reagents (ArN(MgBr)2) condense with nitrosoarenes and nitroarenes giving the corresponding azoarenes and azoxyarenes, respectively. Azoxyarenes were moderately deoxygenated by treatment with excessive amounts of the reagent giving the corresponding azoarenes. The reaction of nitroarenes with differently substituted reagents afforded unsymmetrically substituted azoxy- and azoarenes: Small amounts of symmetrically substituted azoarenes, which originated from the oxidative coupling of the reagent molecules, were also isolated. The distribution of the three types of condensation products are governed by the electronic effect of substituents of both the reagents and the substrates.
Spectrophotometric Determination of Iron(II) after Separation by Collection of Its Ternary Complex of 1,10-Phenanthroline and Tetraphenylborate on Microcrystalline Naphthalene
Authors: Chang Lih-Fen , Satake Masatada , Puri B K , Bag Saswati P
Published: July 2006

A new procedure for the spectrophotometric determination of iron(II) after collection of its ternary complex with 1,10-phenanthroline and tetraphenylborate on microcrystalline naphthalene is described. In the presence of tetraphenylborate, the tris(1,10-phenanthroline)iron(II) ion is quantitatively collected on microcrystalline naphthalene as the ion-association complex. The system conforms to Beer’s law over the range 3–50 μg of iron in 10 ml of the solvent. The molar absorptivity was 1.2×104 l mol cm−1 at 514 nm. The effect of various factors, such as wavelength, pH, amounts of reagent and naphthalene, shaking time, and diverse ions, were also studied. The procedure method was satisfactorily applied to the determination of iron in standard aluminium alloy, aluminium, and magnesium metals.
The Synthesis of (+)-Pisiferol and (+)-Pisiferal
Authors: Matsumoto Takashi , Endo Yoshinori , Okimoto Masaru
Published: July 2006

Reduction of abieta-8,11,13,-trien-6-one with lithium aluminium hydride, followed by treatment with lead tetraacetate and iodine, affored 6β,20-epoxyabieta-8,11,13-triene. This was converted into a separable mixture of abieta-8,11,13-trien-20-ol (13) and 5βH-abieta-8,11,13-trien-20-ol (14) by a series of reactions; ether cleavage with acetic p-toluenesulfonic anhydride, catalytic hydrogenation, and reduction with lithium aluminium hydride. Acetylation of 13 and 14 gave the corresponding acetates, 20-acetoxyabieta-8,11,13-triene (11) and 20-acetoxy-5βH-abieta-8,11,13-triene (12). Friedel-Crafts acylation of 11 with acetyl chloride in the presence of anhydrous aluminium chloride afforded 20-acetoxy-12-acetylabieta-8,11,13-triene, which was converted into pisiferol by oxidation with m-chloroperbenzoic acid and subsequent treatment with lithium aluminium hydride. The synthetic pisiferol was oxidized with Jones reagent to give pisiferal. Similarly, 5βH-abieta-8,11,13-triene-12,20-diol was synthesized from 12. Conversion of the cis A/B ring junctions in 12 into the trans ones is also described.
Synthesis of 6- and 8-Phenyl-substituted Flavonoids
Authors: Matsumura Hisashi , Tsuchiya Toshio , Takeda Tsuneko , Imafuku Kimiaki
Published: July 2006

3-Acetylbiphenyl-4-ol and -2-ol were condensed with substituted benzaldehydes to give respectively 5′-and 3′-phenyl-substituted chalcones (1a–k), which were cyclized to afford 6- and 8-phenylflavanones. The chalcones (1a–k) also gave the corresponding 6- and 8-phenylflavones via dibromides. The effects of the phenyl group on the spectral data are also discussed.
Synthesis of 2-(1-Azulenyl)ethanamine Derivatives by Aminoethylation of Azulenes with Aziridines
Authors: Kurokawa Shinji , Anderson Arthur G
Published: July 2006

Azulene analogs of biological active amines were synthesized. Reaction of azulene or guaiazulene with 1-butanoylaziridine or with 1-butanoyl-2-methylaziridine in the presence of Lewis acid catalyst formed the corresponding N-butanoyl-1-(1-azulenyl)-, N-butanoyl-2-(1-azulenyl)-, and N-butanoyl-2-(1-guaiazulenyl) derivatives of ethanamine, or 1-propanamine, or of 2-propanamine, respectively (5–9). Reaction of guaiazulene with 2-methyl-, or 1,1-dimethylaziridinium, or with 1,1,2,2-tetramethylaziridinium ions gave the corresponding 1-(1-guaiazulenyl)- and 2-(1-guaiazulenyl) derivatives of ethanamine, or 1-propanamine, or of 2-propanamine. 2-(1-Azulenyl)- and 2-(4,6,8-trimethyl-1-azulenyl) derivatives of ethanamine were also obtained by the action of 1,1-diethylaziridinium ion on azulene or on 4,6,8-trimethylazulene. Compounds 5, 6, and 9 were active in vitro in the inhibition of prostaglandin 15-hydroxydehydrogenase and of cyclic AMP-phosphodiesterase.
Structure and Properties of Dichloro(l-proline)cadmium(II) Hydrate
Authors: Yukawa Yasuhiko , Inomata Yoshie , Takeuchi Toshio
Published: July 2006

An X-ray diffraction study of the title complex has been carried out. The crystal is orthorhombic, with the space group P212121; Z=4, a=10.021(3), b=13.562(4), c=7.298(3) Å. Block-diagonal least-squares refinements have led to the final R value of 0.035. The structure is very similar to that of dichloro(4-hydroxy-l-proline)cadmium(II), which has a one-dimensional polymer bridged by chlorine atoms and a carboxyl group like an infinite folding screen. The thermal behavior is, however, different from that of dichloro(4-hydroxy-l-proline)cadmium(II). The difference is likely to be due to a difference of the crystal structure, whether it contains intermolecular hydrogen bonds or not.
Reactions of Dialkylnickel(II) Complexes NiR2L2 with Alkyl (or Aryl) Halides, R′COY (Y=Cl, Br, OPh, OCOPh), and CS2
Authors: Yamamoto Takakazu , Kohara Teiji , Osakada Kohtaro , Yamamoto Akio
Published: July 2006

Reactions of Ni(CH3)2(bpy) (1), Ni(C2H5)2(bpy) (2) (bpy=2,2′-bipyridine), trans-Ni(CH3)2(triethylphosphine)2 (3), Ni(CH3)2(1,2-bis(diphenylphosphino)ethane) (4), and Ni(CH3)2(1,3-bis(diphenylphosphino)propane) (5) with alkyl or aryl halides, R′COY (Y=Cl, Br, OC6H5, OCOC6H5), and CS2 have been investigated. The reactions of NiR2L2 with alkyl or aryl halides are classified into three types of reactions by their reactirn products: Type A: NiR2L2+R′X→NiX(R′)L2+R–R, Type B: NiR2L2+R′X→alkane (RH)+ olefin (R′(–H)), and Type C: NiR2L2+R′X→NiR(X)L2+R–R′. Complexes 1 and 2 undergo mainly Type A reaction. Complex 3 gives Type A reaction product on treatment with C6H5Br, but it gives Type B reaction product on treatment with C2H5Br. On the other hand, 4 undergoes Type C reaction on interaction with C6H5Cl. The reactions with R′COY (Y=Cl, Br, OPh, OCOPh) are classified into two types of reactions by their reaction products: Type D: NiR2L2+R′COY→NiY(R′)L2+RCOR′ and Type E: NiR2L2+R′COY→NiY(R′)L2+RCOR. Complexes 1–3 undergo mainly Type D reaction, whereas complexes 4 and 5 mainly Type E reaction. The difference in the reaction route is discussed on the basis of presence or absence of vacant coordination site for attack by R′COY. The reaction of 4 with CS2 affords Ni(CS2)(1,2-bis(diphenylphosphino)ethane) with evolution of a reductive elimination product, ethane, whereas the reaction of 3 with CS2 gives a 1:1 adduct of 3 and CS2.
Nb2O5 Supported on TiO2. Catalytic Activity for Reduction of NO with NH3
Authors: Okazaki Susumu , Okuyama Tetsuhiro
Published: July 2006

Niobium(V) oxide supported on TiO2 showed a high catalytic activity for the reduction of NO with NH3 at temperatures higher than 450 °C. The presence of SO42− in Nb2O5 or in Nb2O5 supported on TiO2 brought about an increase in the catalytic activity.
Aromatic Nucleophilic Substitution. XVII. Formation and Decomposition of Anionic σ Complexes in Reactions of 2-Acetylaminoethyl 2,6-Dinitrophenyl Ether and N-Acetyl-N-(2-hydroxyethyl)-2,6-dinitroaniline with Potassium t-Butoxide
Authors: Sekiguchi Shizen , Hoshino Ohtomo , Hirai Motohiko , Okada Keiji , Tomoto Noboru
Published: July 2006

Reactions of 2-acetylaminoethyl 2,6-dinitrophenyl ether and N-acetyl-N-(2-hydroxyethyl)-2,6-dinitroaniline with t-butyl alcoholic KOC(CH3)3 in DMSO were followed by UV-VIS and NMR spectroscopies. In both reactions the same spiro anionic σ complex was formed.
Nucleophilic Substitution with Phosphide Anions Prepared by an Action of Sodium Dihydridobis(2-methoxyethanolato)aluminate on Phosphorus Compounds
Authors: Yamashita Mitsuji , Suzuki Nobuyoshi , Yamada Manabu , Soeda Yukio , Yamashita Hiroaki , Nakatani Kaname , Oshikawa Tatsuo , Inokawa Saburo
Published: July 2006

Phosphide anions, prepared by an action of sodium dihydridobis(2-methoxyethanolato)aluminate on derivatives of phosphine, phosphine oxide, or phosphorus esters, react with primary and secondary alkyl halides to produce phosphine derivatives having a newly formed phosphorus-carbon bond. The reactivity increases in the order of chloride<bromide<iodide and of secondary<primary in alkyl halide. Reaction of phosphide anion is also feasible with p-toluenesulfonate. Reaction of an anion of diphenylphosphine oxide seems to proceed mainly as an SN2 type process.
The Corrosion Inhibition of SS 41 Steel by Shoyu Oil
Authors: Sekine Isao , Asazuma Masahiro
Published: July 2006

The addition of shoyu (soy sauce) oil to an NaCl solution for use as a corrosion inhibitor of SS 41 steel was investigated by measuring the corrosion weight loss, the polarization curve, the polarization resistance, and the impedance of the metal-solution interface. The value of the weight loss and the double-layer capacitance, Cdl, decreased as the shoyu oil was added to NaCl solutions of various concentrations. The value of the corrosion current density, Icorr, as calculated from the weight loss, the polarization curve, and the impedance measurement, decreased with an increase in the concentration of shoyu oil. An efficient inhibition of the corrosion of SS 41 steel was observed above an additive concentration of about 0.3%. Thus, the shoyu oil was found to be useful as a corrosion inhibitor of an economical and anti-pollution type. From the results of the IR analysis, the inhibition of the shoyu oil was considered to be caused by the adsorption of fatty acids, especially unsaturated fatty acids involved in the shoyu oil.
Circular Dichroism Spectra and Stereochemistry of Dicyanotetrakis-(diamine)-tetra-μ-hydroxo-tricobalt(III)(3+) Complexes
Authors: Kaki Satoshi , Yamanari Kazuaki , Shimura Yoichi
Published: July 2006

the chiral tetra-μ-hydroxo-trinuclear complexes, cis-[Co(CN)2{(OH)2Co(NH3)4}2]3+ and cis-[Co(CN)2{(OH)2Co(diamine)2}2]3+ have been prepared and separated into their optical isomers and/or diastereomers by column chromatography (diamine: ethylenediamine, (R)-1,2-propanediamine, and (S,S)-1,2-cyclohexanediamine). The absolute configurations of isomers have been assigned on the basis of their CD and 13C NMR spectra and the characterization of mononuclear complex produced by decomposition of the trinuclear isomers of ethylenediamine ligands. It has been proved that the main CD contributions due to the two chiral Co(OH)4(CN)2 and Co(N)4(OH)2 centers are additive for the present systems.
Stereoselective Formation of Rotaxanes Composed of Polymethylenebridged Dinuclear Cobalt(III) Complexes and α- or β-Cyclodextrin
Authors: Yamanari Kazuaki , Shimura Yoichi
Published: July 2006

[2]-[[(en)2Co{NH2(CH2)2S(CH2)nS(CH2)2NH2}Co(en)2]Cl6]-[α- or β-CDX]-rotaxanes were prepared with partial stereoselectivity and characterized from their absorption and 13C NMR spectra, molar conductance, and elemental analysis (CDX=cyclodextrin; n=8, 10, and 12). The rotaxanes always showed apparently ΔΔ-rich. CD spectra, the highest selectivity (16% ΔΔ-rich) being found in the case of n=10 and α-CDX. The results are related to the direct preparation of [2]-[ΔΔ-[(en)2Co{NH2(CH2)2S(CH2)nS(CH2)2NH2}Co(en)2]Cl6]-[α-CDX]-rotaxanes (n=8, 10, and 12) in relatively higher yields than the corresponding ΛΛ rotaxanes: 3.5% for n=8, 21% for n=10, and 28% for n=12. Inclusion complexes of a new type [Co(en)2{NH2(CH2)2S(CH2)nBr}]Cl3·2(α-CDX) were also isolated (n=10 and 12).
Enzymatic Oxygenation of Sulfides with Cytochrome P-450 from Rabbit Liver. Stereochemistry of Sulfoxide Formation
Authors: Takata Toshikazu , Yamazaki Mayumi , Fujimori Ken , Kim Yong Hae , Iyanagi Takashi , Oae Shigeru
Published: July 2006

Stereochemistry of enzymatic oxygenations of various diaryl, dialkyl and aryl alkyl sulfides to the corresponding sulfoxides with hepatic microsomes obtained from phenobarbital pretreated rabbit was investigated in comparison with those of nonenzymatic oxidations. Relative reactivity of the sulfides in the enzymatic oxygenation, based on the yields of the sulfoxides and the amount of oxygen absorption, depends upon the steric demand of the substituent in the oxygenation of 2-substituted thiochroman derivatives. However, such a trend was not observed in the enzymatic oxygenations of various acyclic sulfides. A substantial asymmetric induction on the sulfur atom was always observed (e.g., 54% e.e. for benzyl t-butyl sulfide). Formation of the sulfoxide with R-configuration predominated over that with S-configuration. The enzymatic oxygenation of all the unsymmetrical sulfides examined proceeded via the same steric course. Diastereomeric ratios of the sulfoxides formed in the enzymatic oxygenations of various racemic sulfides bearing alkyl substituents at α-position are markedly favoured more for the trans isomers than for the cis ones, while the ratio was nearly fifty-fifty in the nonenzymatic oxidations with both MCPBA and NaIO4. These results suggest that the enzymatic oxygenation takes place at the less hindered side of the sulfide. Both enzymatic and nonenzymatic oxidations of rigid six-membered cyclic sulfides, trans-thiadecalins and 4-(p-chlorophenyl)thiane, similarly occurred at the less hindered side to give mainly equatorial sulfoxides. The yields of the four stereoisomeric sulfoxides were nicely determined in the enzymatic oxygenation of racemic 2-methyl-2,3-dihydrobenzothiophene to elucidate the steric course of the oxygenation. Dependency of this microsomal oxygenation upon cytochrome P-450 enzyme was proved by several inhibition experiments and also by the identical stereochemical results of the oxygenation of a few selected sulfides to those with a reconstituted system with purified cytochrome P-450 and co-factors.
Reactions of NH Radicals. I. Photolysis of HN3 Vapor at 313 nm
Authors: Kodama Sukeya
Published: July 2006

Photolysis of HN3 vapor was studied at 313 nm as a function of HN3 and Xe pressures, light intensity, and temperature. The photolysis of hydrazoic acid labeled with 15N was also studied. The quantum yields of N2, H2, and NH4N3 as a product were 4.85, 0.494, and 0.842 at 30 °C and 6.7 kPa of HN3, respectively. The mechanism for the main reactions was postulated as follows: HN3+hν(313 nm)→N2+NH(a1Δ); NH(a1Δ)+HN3→2N2+2H (2); NH(a1Δ)+HN3→N3+NH2 (3); NH(a1Δ)+HN3→N2+N2H2* (4). The rate constant ratios of k3⁄k2=0.746 and k4⁄k2=1.23 were obtained at 30°C. (k3+k4)⁄k2 decrease drastically with rising temperature. Xe is effective for the collisional deactivation, NH(a1Δ)+Xe→NH(X3Σ−)+Xe (15), and k15⁄(k2+k3+k4)=0.187 was obtained at 30 °C.
Effects of Pressure on Dielectric Relaxation in Supercooled Triphenylchloromethane–o-Terphenyl Solution
Authors: Naoki Motosuke , Matsushita Manabu
Published: July 2006

Dielectric measurements have been made as a function of frequency, temperature, and pressure on a binary mixture of triphenylchloromethane and o-terphenyl in its supercooled liquid region. Since the distribution of relaxation time is independent of temperature and pressure in the present experimental range, the time-temperature-pressure superposition is accurately applied. The activation parameters such as the activation enthalpy at constant pressure, H*P, the activation enthalpy at constant volume, H*V, and the activation volume V* are obtained as a function of temperature and pressure. H*V is only half H*P unlike liquids and associated liquids such as alcohols. V* as well as the pressure coefficient of temperature at constant relaxation time τ, (∂T⁄∂T)τ, is similar in magnitude to that of polymer liquids and larger than that of associated liquids. These facts have revealed the contributions of inter- and intramolecular interactions to the molecular mobility in the supercooled liquid. (∂T⁄∂P)τ coincides with the pressure coefficient of the glass transition temperature, dTg/dP. This gives a statement that the glass transition temperature in simple normal liquids, as well as in polymer liquids, is an isorelaxation-time state.
Effect of Pressure on the Adsorption of 1-Octadecanol at Oil/Water Interfaces
Authors: Iyota Hidemi , Aratono Makoto , Yamanaka Michio , Motomura Kinsi , Matuura Ryohei
Published: July 2006

In order to investigate the effect of pressure on the adsorption at interfaces, the interfacial tension was measured as a function of pressure and composition for the systems of water and dilute solutions of 1-octadecanol in cyclohexane, benzene, and their equimolar mixture. The interfacial density of 1-octadecanol and the volume of interface formation were evaluated from the experimental data. Under atmospheric pressure, cyclohexane exhibits a significant adsorption of 1-octadecanol and a rapid decrease in the volume of interface formation, giving rise to the phase transition from the expanded to the condensed state in the adsorbed film, while benzene and equimolar mixture display only a small decrease in the thermodynamic quantities on the 1-octadecanol adsorption. Under high pressure, however, all the systems studied cause the phase transition. The effects of pressure and solvent on the phase transition of the adsorbed film were revealed on the basis of the thermodynamic quantities.
Crystal Structure of N-Benzyl-α-methoxycarbonylmethanimine N-Oxide
Authors: Inouye Yoshinobu
Published: July 2006

The geometry of N-benzyl-α-methoxycarbonylmethanimine N-oxide in the crystalline state was established to be Z by X-ray crystal analysis. The crystal was monoclinic, space group Pc, a=11.069(1), b=5.2335(7), c=8.620(1) Å, β=105.37(1)°, Z=2. The final R value was 0.037 for 1760 reflections.
The Substituent Effects in Thiophene Compounds. I. 1H NMR and IR Studies in Methyl (Substituted 2-Thiophenecarboxylate)s
Authors: Satonaka Hajime
Published: July 2006

The 1H NMR spectra and the IR carbonyl stretching frequencies of methyl (3-, 4-, and 5-substituted 2-thiophenecarboxylate)s have been reported. Good linear correlations between the chemical shifts of the ring protons in methyl (4- and 5-substituted 2-thiophenecarboxylate)s and those of the corresponding protons in substituted thiophenes were observed. The coupling constants in methyl (substituted 2-thiophenecarboxylate)s gave good correlations against the corresponding ones in substituted thiophenes. The IR carbonyl stretching frequencies in methyl (5-substituted 2-thiophenecarboxylate)s were correlated reasonably well with the chemical shifts of 5-protons in 2-substituted thiophenes. The coupling constants in methyl 2-thiophenecarboxylate series were found to vary linearly with the electronegativities of the substituents.
Decomposition of Hydrogen Bromide or Iodide by Gas Phase Electrolysis
Authors: Kondo Wakichi , Mizuta Susumu , Oosawa Yoshinao , Kumagai Toshiya , Fujii Kinjiro
Published: July 2006

Gas phase electrolysis of HBr or HI was studied by using a fuel-cell-type electrolyzer provided with graphite gas diffusion electrodes and liquid film electrolyte of H3PO4. Current efficiency 100% may be achieved at decomposition voltages of 0.73 V (at 100 mA cm−2 and 150 °C) for HBr and 0.28 V (at 100 mA cm−2 and 145 °C) for HI. Both bromine and iodine produced may smoothly be evolved out of the anode in the gas or liquid form without being dissolved into the electrolyte H3PO4, causing no trouble on the separation of products. This electrolytic method may be incorporated in the bromine or iodine cycles for thermochemical hydrogen production to constitute an effective hybrid system.
Laser Excitation Spectrum of the Ã2A′(004) ← \~{X}2A″(000) Band of HSO Radical
Authors: Satoh Masayoshi , Ohashi Nobukimi , Matsuoka Shin-ichi
Published: July 2006

The dye laser excitation spectrum of the Ã2A′(004)←\~{X}2A″(000) vibronic band of HSO was observed and analyzed in the frequency range from 17132 to 17182 cm−1. 414 spectral lines were assigned to an ordinary c-type transition and 21 lines to an axis-switching transition. The rotational constants of HSO in the Ã2A′(004) state were used to calculate the inertia defect of 0.518 u Å2 for this state. A relatively large dependence of the centrifugal distortion constant on the vibrational quantum number was also found.
The Location and Microenvironment of Dimerizing Cationic Dyes in Lipid Membranes as Studied by Means of Their Absorption Spectra
Authors: Handa Tetsurou , Ichihashi Chikako , Yamamoto Izumi , Nakagaki Masayuki
Published: July 2006

The absorption spectra of three cationic dyes, Methylene Blue (MB), 3,3′-dipropyl-2,2′-thiadicarbocyanine (diS-C3(5)), and 9-aminoacridine (9-AA), were measured in aqueous suspensions of a phospholipid membrane and a surfactant micelle. The dyes were intensely partitioned into the membrane phase and dimerized to exhibit a remarkably large reduction in absorbance. The increase in the amount of the membrane beyond the amount where all the dye molecules were dimerized in the membrane phase resulted in a gradual increase in the absorbance due to the increase in the available membrane volume and the dilution of dye in the membrane phase. The changes in the wave lengths of the absorption maxima of the dye monomers by the partitioning into membrane thus obtained were interpreted in terms of the effective polarities of the dye surroundings (microenvironments). It was found that the rather hydrophobic diS-C3(5) penetrates deeply into the membranes and the micelles and is located in considerably nonpolar microenvironments, while MB remains at the polar-surface regions of the membranes and the micelles. On the basis of these results, the structures of the micelles and membranes are discussed.
A Study of the Redistribution Reaction of Tetramethyltin with Dimethyltin Dichloride in Several Aprotic Solvents
Authors: Yamashita Yukihide , Saito Koji , Yoshino Akihiro , Takahashi Kensuke
Published: July 2006

The redistribution reaction of tetramethyltin with dimethyltin dichloride was studied in eight aprotic solvents by using the 1H NMR technique. The second-order rate constant of the reaction (In k2) is proportional to the dielectric constant of the solvent. There is a weak relation between the rate constants (In k2) and the values of 2J(Sn–H) of Me2SnCl2 in several solvents, which are considered to be related to the coordination ability of the solvents. The rate constants are also related to Kosower’s Z values of the solvents. The activation entropies of the reaction in four typical solvents have large negative values. This predicts that the reaction proceeds via a four-center transition state.
ESR Studies of Bunsen-type Methane-Air Flames. I. Effects of the Entrainment and Diffusion of Secondary Air on the Chemical Reactions in the Flame
Authors: Claesson Ola , Noda Shoji , Yoshida Hiroshi
Published: July 2006

H atoms in a Bunsen-type methane-air flame have been studied by observing their ESR signals at different flow rates of O2 and N2 in a synthetic secondary air. The optical emissions from excited CH, C2, and OH radicals in the same flame have been also studied. It has been found that an increased O2 flow rate produces changes in the intensity of the ESR and emission signals, and that it also increases the burning velocity in the inner-cone flame. An increased N2 flow rate, on the other hand, has almost no effect on the flame. The inner-cone of a Bunsen-type flame is, therefore, not a completely premixed flame; it is affected chemically by the secondary air.
Stereochemical Studies of the Electrolytic Reactions of Organic Compounds. Part 18. Comparative Study of Hydrogenation on Metal-black Cathodes and Catalysts
Authors: Nonaka Tsutomu , Takahashi Masahiko , Fuchigami Toshio
Published: July 2006

Stereoselective hydrogenation on metal-black cathodes and catalysts, which were prepared by electrode-position under the same conditions, was comparatively investigated. Stereoisomeric ratios of alcohols formed from the ketones on the Pd- and Pt-black cathodes seemed to be almost equal to those on the corresponding metal-black catalysts, while the yields were quite different between the cathodic and catalytic hydrogenations. On the other hand, results of the hydrogenation of the acetylenes on the cathodes were also different, in not only the yield but also the isomeric ratio, from those on the catalysts. In addition to stereoselectivity, relative hydrogenation rates between cis- and trans-olefins were compared in both the cathodic and catalytic hydrogenations. It was also found that a mercury pool cathode gave quite different stereochemical results in the hydrogenation of the unsaturated compounds from those obtained with either the metal-black cathodes or the catalysts.
Kinetic Pressure and Substituent Effects on the Thermal Isomerization of Triphenylformazans
Authors: Sueishi Yoshimi , Nishimura Norio
Published: July 2006

The rates of the thermal isomerizations around N=N (Process A) and C=N (Process B) of substituted triphenylformazans were followed spectrophotometrically at various temperatures and under high pressures, and the activation parameters were determined. The values of the activation energy, entropy, and volume were found to be ca. 70 kJ mol−1, ca. −20 J K−1 mol−1, and ca. −5.0 cm3 mol−1 respectively for Process A, and ca. 40 kJ mol−1, ca. −200 J K−1 mol−1, and ca. −10 cm3 mol−1 respectively for Process B. It was suggested that the thermal isomerizations both for Processes A and B proceed by the inversion mechanism. Furthermore, in the transition state of Process B, a quasi six-membered ring was assumed to form. The very large negative entropy of Process B was discussed in terms of the restricted internal rotations, and others.
Preparation and Stereochemistry of Cobalt(III) Complexes with S-Alkyl-l-cysteinate, N,N′-Trimethylenebis(S-methyl-l-cysteinate), and S,S′-Ethylene(or -Trimethylene)bis(l-cysteinate)
Authors: Konno Takumi , Okamoto Ken-ichi , Hidaka Jinsai
Published: July 2006

Five cobalt(III) complexes of [Co(terdentate-N,S,O)2] and [Co(sexidentate-N2,S2,O2)] types were prepared; here terdentate-N,S,O denotes S-ethyl-l-cysteinate (l-sec) and S-benzyl-l-cysteinate (l-sbc), and sexidentate-N2,S2,O2 denotes N,N′-trimethylenebis(S-methyl-l-cysteinate) (l,l-tbsmc), S,S′-ethylenebis(l-cysteinate) (l,l-ebc), and S,S′-trimethylenebis(l-cysteinate) (l,l-tbc). Three isomers, trans(S), trans(N), and trans(O), were chromatographically isolated for each of the bis l-sec and l-sbc complexes, while only the trans(O) isomer was isolated for each of the l,l-tbsmc, l,l-ebc, and l,l-tbc complexes. These isomers were characterized from their absorption, CD, and 1H and 13C NMR spectra. The trans(O) isomers of the bis type and l,l-tbsmc complexes, which were assigned to a mixture of R(S),R(S), R(S),S(S), and S(S),S(S) configurations concerning the coordinated sulfur atoms, showed a similar CD spectral behavior to each other in the whole region. The trans(O)-R(S),R(S) l,l-ebc isomer and trans(O)-S(S),S(S) l,l-tbc one showed characteristic absorption and CD spectral behavior in the sulfur-to-metal charge transfer band region.
Reaction Process of Zirconium Tetrachloride with Ammonia in the Vapor Phase and Properties of the Zirconium Nitride Formed
Authors: Yajima Akimasa , Segawa Yutaka , Matsuzaki Ryoko , Saeki Yuzo
Published: July 2006

The reaction products of gaseous ZrCl4 with ammonia were ZrCl4·2NH3 at 300 °C; ZrCl4·2NH3, ZrClN, and NH4Cl at 350–700 °C; ZrCl4·2NH3, ZrClN, ZrNx, Zr3N4, and NH4Cl at 750 °C; ZrClN, ZrNx, Zr3N4, and NH4Cl at 800–950 °C: ZrNx, Zr3N4, and NH4Cl at 1000–1050 °C; and ZrNx, NH4Cl, and HCl at 1100–1400 °C. The N/Zr atomic ratios, x, of the ZrNx formed was 1.28 at 1100 °C, 1.24 at 1200 °C, 1.18 at 1300 °C, and 1.12 at 1400 °C. The lattice constants of the ZrNx formed were shown. The reaction process of gaseous ZrCl4 with ammonia can be represented as follows: The reaction of gaseous ZrCl4 with ammonia to form ZrCl4·2NH3 occurs first. Above ca. 330 °C, the ZrCl4·2NH3 reacts with ammonia to form ZrClN. Above ca. 750 °C, the ZrClN reacts with ammonia to form ZrNx and Zr3N4. Above ca. 1000 °C, ZrNx. was also formed by the thermal decomposition of the Zr3N4. On heating the ZrNx(x=1.28), formed by the vapor-phase reaction, at temperatures higher than 700 °C in an argon atmosphere, the value of x decreased and became close to that of the stoichiometric nitride, being 1.03 at 1100–1300°C.
A Solid State Electrochemical Study on the 5,6 : 11,12-Bis(epidithio)naphthacene–Iodine and Bromine Complexes
Authors: Chino Eiji , Matsunaga Yoshio , Tanabe Noboru
Published: July 2006

Electromotive force (emf) measurements were made on solid-state galvanic cells, Ag|AgI|TTT–In, where TTT–In is the 5,6:11,12-bis(epidithio)naphthacene–iodine complex, as functions of the composition, n, and also of the temperature. A continuous increase in the emf at 25 °C from 491 to 593 mV was observed in the range from n=1.0 to 1.5, suggesting the occurrence of a nonstoichiometric phase. The upper limit of the existence region agrees with the composition of the well-known metallic phase. The emf changes again continuously up to 628 mV in the range from n=2.7 to 2.9, which corresponds with the composition of another highly-conducting complex. Similar measurements were carried out for the cells Ag|AgBr|TTT–Brn. Distinct phases were found at the following compositions: n=0.5–0.8, about 1, about 1.2, about 1.5, and about 2. The Gibbs energy, enthalpy, and entropy of cell reactions as well as complex formation reactions were estimated.
Product Distribution in Degradation of Polypropylene over Silica-Alumina and CaX Zeolite Catalysts
Authors: Uemichi Yoshio , Kashiwaya Yasunori , Tsukidate Masaya , Ayame Akimi , Kanoh Hisao
Published: July 2006

The composition of degradation products of polypropylene, especially liquid fraction, formed over silica-alumina and CaX zeolite catalysts was investigated extensively. The catalysts gave almost the same product distribution as a function of carbon number at the initial stages of the reaction. The liquid fractions were rich in the same isoalkanes and aromatics as those contained in the gasoline fraction. Most of the isoalkanes were methyl-branched, while the aromatics consisted mainly of those with one or more methyl groups. The catalytic degradations involved extensive aromatization, isomerization and hydrogen transfer as secondary reactions. The difference in catalytic behaviors between silica-alumina and CaX was most remarkable in coke deposition on the catalysts and more deposition on CaX led to greater saturation of the products. The H/C ratio of the products was regarded as a good measure for the degree of coke formation on the catalyst surfaces.
Colloidal Rhodium Dispersions Protected by Cyclodextrins
Authors: Komiyama Makoto , Hirai Hidefumi
Published: July 2006

Refluxing of an aqueous solution of rhodium(III) chloride and α- or β-cyclodextrin, followed by further refluxing in the presence of ethanol, gives a colloidal dispersion of rhodium particles of 28 Å in diameter. The colloidal dispersion exhibits effective catalyses in hydrogena-tion of olefins at 30 °C under an atmospheric pressure.
A Photochemical Storage Battery with an n-GaP Photoelectrode
Authors: Yonezawa Yoshiro , Okai Makoto , Ishino Masato , Hada Hiroshi
Published: July 2006

We have constructed a photochemical storage battery with an n-GaP Photoelectrode. A two-compartment cell, n-GaP|aqueous K3[Fe(CN6]–K4[Fe(CN)6||aqueous NiSO4|Pt, is capable of being charged by the irradiation of the photoelectrode. The current efficiency of nickel deposition on the storage electrode was 80%. When we drew electrical energy out of the dattery, the deposited nickel could act as a Ni electrode in the Ni2+ solution. The power efficiency of the storage battery amounted to about 2%. We could recharge the battery more than five times after discharge.
Microscopic Viscosity of the Interior Water Pool in Dodecylammonium Propionate Reversed Micelles
Authors: Tsujii Kaoru , Sunamoto Junzo , Fendler Janos H
Published: July 2006

13C-Chemical shifts and spin lattice relaxation times have been determined for dodecylammonium propionate/water/benzene or CCl4 reversed micelles and for [13C]glycine cosolubilized therein. Data obtained have been discussed in terms of the mobility of glycine molecules being effectively isolated from the surfactant headgroups by water molecules. The determined relaxation times of [13C]glycine in glycerol-water mixtures correlated well with the macroscopic and microscopic viscosities of the reversed micellar solution. In a relatively small water pool, the apparent viscosity of water surrounding glycine in the micelle (microviscosity) was corresponding to that of 78% aqueous glycerol solution. Increasing the size of water pool resulted in decrased microviscosities.
Particle Size of Nickel in Nickel–Alumina Catalysts and Its Effects on Propene Hydrogenation
Authors: Takai Yoriko , Ueno Akifumi , Kotera Yoshihide
Published: July 2006

The particle size of nickel in Ni/Al2O3 catalysts prepared by the alkoxide technique is well controlled by changing the metal concentration in the catalyst. The rate of propene hydrogenation over the catalyst increases with decrease in Ni particle size, and this phenomenon is explained on the assumption that nickel atoms located on edges and/or corners of crystallites may contribute predominantly to the hydrogenation of propene.
A Novel Synthesis of α-Methylene-γ-butyrolactones
Authors: Saimoto Hiroyuki , Nishio Koji , Yamamoto Hajime , Shinoda Masaki , Hiyama Tamejiro , Nozaki Hitosi
Published: July 2006

A new method is reported for constructing α-methylene-γ-butyrolactone moiety under neutral, anhydrous conditions. Olefin–dibromocarbene adducts were transformed into methyl 1-(dimethylaminomethyl)cyclopropanecarboxylates (3). Treatment of 3 with trimethylsilyl iodide followed by thermolytic distillation of the crude products gave α-methylene-γ-butyrolactones with high regio- and stereo selectivity.
The Conformational Analysis of 1-p-Tolyl-2-phenyl-1-propanols, 1-p-Tolyl-2-phenylethanol, and 1-p-Tolyl-2-phenyl-1-propanone by Means of NMR Spectroscopy
Authors: Kunieda Norio , Endo Hiroko , Hirota Minoru , Kodama Yoshio , Nishio Motohiro
Published: July 2006

The conformations of the diastereomers of 1-p-tolyl-2-phenyl-1-propanols[(RS⁄SR)-3 and (RR⁄SS)-3], 1-p-tolyl-2-phenylethanol (4), and 1-p-tolyl-2-phenyl-1-propanone (5) were studied by means of NMR spectroscopy, mostly with the aid of the computer-simulation of the lanthanoid-induced shifts. It has been suggested that the rotamers in which the tolyl group lies close to the phenyl group are preferred in the conformational equilibria of (RS⁄SR)-3, 4, and 5. For(RR⁄SS)-3, the most stable rotamer (in CDCl3) has been suggested to have the tolyl group anti to the phenyl group and gauche to the methyl group. The results have been discussed in view of the general occurrence of the folded conformation.
Kinetics and Mechanism of the Addition of Iodine Monochloride to Alkenes in Acetic Acid
Authors: Amirtha Nagarajan , Viswanathan Seshaiyer , Ganesan Ramachandran
Published: July 2006

A kinetic investigation of the addition of iodine monochloride (ICl) to some allyl and vinyl compounds in dry acetic acid medium has been carried out at 20,30,40, and 50 °C. In all the cases, the reaction obeys a total third order kinetics, second order in ICl and first order in the substrate. The product formed has been analysed by 1H NMR technique. The reaction stoichiometry was found to be 1:1. The formation of a 1:1 complex between an alkene and ICl has been established for the first time spectrophotometrically and the equilibrium constant evaluated. The effect of the addition of the chloride ion on the reaction rate has been studied. The kinetic and thermodynamic parameters evaluated strongly suggest a mechanism involving dipole-dipole interaction with a bridged iodonium ion intermediate.
Enthalpies of Combustion of Organic Compouds. V. 3- and 4-Nitroanilines
Authors: Nishiyama Keiichi , Sakiyama Minoru , Seki Syûzô
Published: July 2006

Precision oxygen bomb combustion calorimetry was carried out for the title compounds in the crystalline states. Standard enthalpies of formation at 298.15 K for the crystalline and gaseous states were derived.
Excimer Formation and Phase Separation of Hydrocarbon and Fluorocarbon Bilayer Membranes
Authors: Kunitake Toyoki , Tawaki Shin-ichiro , Nakashima Naotoshi
Published: July 2006

The benzene chromophore contained in double-chain(hydrocarbon) ammonium amphiphiles gives both of monomer and excimer fluorescence in the fluid(liquid crystalline) bilayer organization. The excimer emission disappears by phase transition to the rigid(crystalline) bilayer. In contrast, the corresponding fluorocarbon bilayer, in the absence of phase transition phenomena, shows excimer emission at all temperatures(15–50 °C). The excimer emission decreases when these probe amphiphiles are diluted in matrix bilayers. These results are applied to study the phase separation behavior of hydrocarbon and fluorocarbon bilayer membranes. The fluorocarbon bilayer is not extensively miscible with the hydrocarbon bilayer, and vice versa. The miscibility is influenced additionally by the chemical structure of amphiphiles. The rate of mixing is determined by the component miscibility as well as by the aggregate morphology. The DSC study supports these conclusions and further indicates that an unsymmetrical, double-chain (one hydrocarbon and one fluorocarbon chains) amphiphile can promote mixing of typical hydrocarbon and fluorocarbon bilayers.
Copper(II)-Sulfur Interactions in Pyridine- and Imidazole-containing Disulfide Complexes. Syntheses, Spectra, and Solution Equilibria
Authors: Yamauchi Osamu , Seki Hiroko , Shoda Toshiya
Published: July 2006

Synthetic, spectroscopic, and potentiometric studies on the copper(II) complexes of pyridine-, quinoline-, and imidazole-ring-containing disulfides and related compounds have been made with emphasis on copper(II)–sulfur interactions. In the presence of copper(II), disulfide ligands, (RCH2NHCH2CH2S–)2, where R=4-imidazolyl (IMAD), 2-pyridyl (PMAD), 6-methyl-2-pyridyl (MPAD), and 2-quinolyl (QMAD), are more stable in acid solution than in neutral–alkaline solution. A stable 1 : 1 copper(II) complex, Cu(IMAD)(ClO4)2·H2O, was isolated as crystals from aqueous solution, whereas a binuclear complex, Cu2(PMAD)Cl4, was obtained as crystals in ethanol. The Cu(II)–IMAD systems exhibit a single d-d peak at 585 nm indicative of a CuN4 chromophore but no charge transfer (CT) band in the region 300–900 nm. The other Cu(II)–disulfide systems exhibit d-d bands at 650 and ≈850 nm. A shoulder at 310–330 nm observed for the Cu(II)–PMAD and –MPAD systems at pH ≈4 and >6, respectively, is assigned to the S→Cu(II) CT transition. Thioether ligands, N-(2-pyridylmethyl)-l-methionine and N-(4-imidazolylmethyl)-Dl-methionine, show the S→Cu(II) CT peak at ≈310 nm at pH 9 in the 1 : 1 Cu(II)–ligand systems. Equilibrium constants of the proton-ligand and Cu(II)–ligand systems were determined by pH titrations at 25 °C and I=0.1(KNO3). The Cu(II)–disulfide systems were analyzed by considering monomeric species CuL, CuLH, and CuLH2 (L=ligand; H=proton) and a binuclear species Cu2L; the logβ110 values for CuL are 13.38, 13.32, and 9.46 for L=IMAD, PMAD, and MPAD, respectively. Conductivity measurements showed that the Cu(II)–IMAD complex isolated as crystals is monomeric in aqueous solution. Comparison of the electronic absorption and electron spin resonance spectral data and stability constants for various systems suggests that Cu(II)–PMAD has a square-pyramidal CuN4S chromophore with a sulfur atom in an equatorial position, whereas Cu(II)–IMAD has a planar CuN4 chromophore. The stability of disulfide bonds in copper(II) complexes in aqueous solution is briefly discussed on the basis of the modes of coordination.
Reaction of Quinoxaline Derivatives with Nucleophilic Reagents
Authors: Badr Mahmoud Zarif Amin , El-Naggar Galal Mohamed , El-Sherief Hassan Ahmad Hassan , Abdel-Rahman Abdou El-Sayed , Aly Moustafa Fouzy
Published: July 2006

2-Chloro-3-methylquinoxaline reacts with aromatic amines in basic medium forming 2-arylamino-3-methylquinoxalines, also it reacts with mercaptoacetic acid. The 3-methyl-2(1H)-quinoxalinone condenses with aromatic aldehydes forming the corresponding 3-(substituted styryl)-2(1H)-quinoxalinones which add bromine in acetic acid to yield the corresponding dibromo derivatives which react with morpholine, sodium methoxide, and piperidine to give the corresponding compounds. 3-Methyl-2(1H)-quinoxalinone undergoes side-chain bromination to yield 3-bromomethyl-2(1H)-quinoxalinone, which reacts with aromatic amines, sodium salt of saccharine, potassium phthalimide··· 3-Methyl-2(1H)-quinoxalinone with P2S5 gave 3-methyl-2(1H)-quinoxalinethione which reacts with 2-aminoethanol, dimethyl sulfate, and halo acids.
Solvent Effects on Dimerization of Copper(II) Decanoate in Alcohol Solvents
Authors: Yamada Hiromichi , Kitazaki Ryoji , Kakimi Ikuo
Published: July 2006

The extraction of copper(II) with decanoic acid in some alcohol solvents was carried out at 25 °C and at 0.1 mol/dm3 (NaClO4) aqueous ionic strength. Alcohols used are cyclohexanol, 1-pentanol, 1-hexanol, and 1-heptanol. In these solvents, monomeric and dimeric copper(II) decanoates are responsible for the extraction. Species involved in each organic phase are CuA2, Cu2A4, and Cu2A4(HA)2 (HA: decanoic acid). The dimerization and adduct formation of copper(II) decanoates in each organic phase are written as:

2CuA2\oversetKdim−1\ightleftharpoonsCu2A4

Cu2A4+2HA\oversetβad,dim\ightleftharpoonsCu2A4(HA)2

The following dimerization and adduct formation constants were obtained: logKdim−1=2.23 and logβad,dim=0.26 for cyclohexanol, 2.26 and −0.03 for 1-pentanol, 2.77 and −0.04 for 1-hexanol, and 3.04 and −0.24 for 1-heptanol, respectively.
Relative Stabilities of 2n Framework Electron Clusters. Perhalogenated Neutral closo-Boranes
Authors: Aihara Jun-ichi
Published: July 2006

As in the case of the closo-borane dianions, relative stabilities of the title compounds can be elucidated by means of the graph theory of aromaticity.
Intermolecular Pummerer Rearrangement Reactions of Alkyl Phenyl and Dialkyl Sulfoxides with Acetic Anhydride
Authors: Itoh Osamu , Numata Tatsuo , Yoshimura Toshiaki , Oae Shigeru
Published: July 2006

The Pummerer reactions of alkyl phenyl sulfoxides, PhS(O)R (R: methyl and isobutyl), and benzyl methyl sulfoxide with acetic anhydride were found to proceed through the intermolecular acetoxyl migration, based on the 18O-tracer experiments with 18O-labeled sulfoxides and unlabeled acetic anhydride.