bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of cis-Aryl Cyclopropyl Sulfones
Authors: Balaji T , Reddy D Bhaskar 
Published: July 2006

Abstract
Some new cis-1-(arylsulfonyl)-2-phenylcyclopropanes have been synthesized by the addition of arylthiocarbenes to styrene in presence of excess potassium t-butoxide at low temperatures. The (arylthio)cyclopropanes thus obtained are subsequently oxidized with 30% hydrogen peroxide in acetic acid to corresponding sulfones. The IR and PMR spectra of all these compounds were recorded. Their IR spectra displayed bands in the region 1033–1008 cm−1 which are considered to be the most characteristic of the cyclopropane ring. They have also exhibited bands in the region 850–820 cm−1 characteristic of cis-configuration. The PMR spectra gave complex multiplets in the region 1.4–3.1 ppm. A study of these chemical shifts for ring protons and other substituents reveals that all the substituents tend to cause protons cis-to them to appear at higher fields than those trans-to them. Thus the differences of the chemical shifts can be used as a criterion to distinguish between cis-and trans-1-(arylsulfonyl)-2-phenylcyclopropanes.
Resonance Energy Stabilization in Crystalline Ion Radical Salts
Authors: Iida Yôichi 
Published: July 2006

Abstract
In solid ion radical salts, the ion radical molecules form a segregated stacking into columns, and the charge-transfer interaction occurs between ion radicals. The resonance energy stabilization due to the charge-transfer interaction was estimated for non-alternant one-dimensional system of solid ion radical salts.
Synthesis and Magnetism of Cobalt(II)–Manganese(II)–Cobalt(II) Trinuclear Complexes with N,N′-Disalicylidenealkanediamines
Authors: Kasempimolporn Visit , Okawa Hisashi , Kida Sigeo 
Published: July 2006

Abstract
Cobalt(II)–manganese(II)–cobalt(II) trinuclear complexes were synthesized by reacting N,N′-disalicylidenealkanediaminatocobalt(II) and manganese(II) halide in a 2:1 mole ratio. Cryomagnetic measurements indicated an antiferromagnetic spin-exchange interaction operating between the low-spin cobalt (II) and the high-spin manganese(II) ions, exchange integrals being estimated at −8–−12 cm−1.
Nucleophilic Substitution on Dialkoxy Bisulfides. II. Reactions with Hydrazine Derivatives
Authors: Kagami Hiroaki , Motoki Shinichi 
Published: July 2006

Abstract
Diethoxy disulfide (1) reacted with arylhydrazines to give arylbenzenes, diaryl sulfides, and aryl ethoxy tetrasulfides. The reaction of 1 with hydrazobenzenes gave azobenzenes in quantitative yields. The treatment of 1 with 1,5-diphenylthiocarbonohydrazide or 1,5-diarylthiocarbazones afforded 2,3-diaryltetrazolium-5-thiolates.
Photochemical Ethoxycarbonylmethylation of Anisole with Ethyl Chloroacetate in the Presence of Zinc Chloride
Authors: Izawa Yasuji , Tomioka Hideo , Kutsuna Masato , Toyama Yasuo 
Published: July 2006

Abstract
Irradiation of ethyl acetate solution of anisole and ethyl chloroacetate in the presence of ZnCl2 gave ethyl o-, m-, and p-methoxyphenylacetates (3) (28.6–48%). The similar ethoxycarbonylmethylation in anisole–ethyl acetate (9:1) resulted in higher yields (80–81%) of 3. The results on the positional and substrate selectivities imply that ZnCl2-participated attacking species would play an important role in the present ethoxycarbonylmethylation.
The BF3 Catalyzed Decomposition of Diazo Compounds in the Presence of Carbonyl Compounds
Authors: Ibata Toshikazu , Miyauchi Kazuo , Nakata Seiji 
Published: July 2006

Abstract
The BF3 catalyzed decomposition of diazo ompounds such as α-diazoacetophenones, ethyl diazoace-tate, and diphenyldiazomethane in the presence of cyclic β-diketones gave the corresponding enol ether. Used as a substrate, cyclohexanone gave the ring expanded homologation product.
Reaction of N,N-Dialkylanilines with Palladium(II) Compounds
Authors: Sakakibara Tsutomu , Dogomori Yoko , Tsuzuki Yuichiro 
Published: July 2006

Abstract
The reaction of N,N-dialkylaniline with palladium(II) acetate or di-μ-acetato-bis[α-(dimethylamino)-o-tolyl]dipalladium (B) gave 4,4′-bis(dialkylamino)diphenylmethane as a major product. It was elucidated that the origin of –CH2– in the product might be methyl group of palladium acetate and the primary reaction product might be N,N-dialkyltoluidine. The absorption spectra of the initial reaction mixture of N,N-dimethylaniline with B in acetic acid at room temperature showed the absorption maximum at 470 nm and at 750 nm. The latter peak was tentatively assigned to N,N-dimethylaniline radical cation-palladium (I) acetate complex, which was suggested as a key-intermediate for the formation of diarylmethanes.
The Mechanism of the TEA CO2 Laser-induced Reaction of 1,1-Dichloroethane
Authors: Nagai Keiichi , Katayama Mikio 
Published: July 2006

Abstract
In a TEA CO2 laser-induced reaction of 1,1-dichloroethane, the relative quantities of the products, C2H2 and ClHC=CH2, were found to vary with the laser wavelength, indicating that the C2H2 molecules are produced by two processes, directly and indirectly from Cl2HC–CH3 within the duration of a single laser pulse.
The Effect of Halo Ligand on the Rate of Hydrogenation of Coordinated Olefin in Dihydrido-olefin Complexes RhXH2(ol) (PPh3)2 (X=Cl, Br, I)
Authors: Ohtani Yoshimi , Yamagishi Akihiko , Fujimoto Masatoshi 
Published: July 2006

Abstract
The formation constant of RhXH2(ol)(PPh3)2 (ol=acrylonitrile or styrene, X=Cl, Br, or I) and the rate of hydrogenation of coordinated olefin in RhXH2(ol)(PPh3)2 were determined. The effects of halo ligand on the equilibrium and rate constants showed a different trend for the two olefin complexes.
Synthesis of 2,5-Diphenylbicyclo[4.2.0]octa-2,4-diene. Exclusive Existence in the Bicyclic Form and a Correction of the Reported Structure of 2,5-Diphenyl-1,3,5-cyclooctatriene
Authors: Oda Masaji , Kanao Yoshinori 
Published: July 2006

Abstract
2,5-Diphenylbicyclo[4.2.0]octa-2,4-diene has been found to exist exclusively in the bicyclic form, giving rise to questioning the reported structure of 2,5-diphenyl-1,3,5-cyclooctatriene. The structure of 1,4-diphenyl-1,3,6-cyclooctatriene is proposed for the compound.
Flux Growth of Double Oxide Crystals of Tantalum and Rare-earth Elements
Authors: Yamasaki Yuichi , Sugitani Yoshinori 
Published: July 2006

Abstract
Crystals of GdTaO4, DyTaO4, and ErTaO4, and those of Gd3TaO7, Y3TaO7 and Er3TaO7 have been grown by PbF2–PbO flux. Solid solution crystals of YTaO4 and YNbO4 have been obtained for the starting composition of YTaxNb1−xO4(x&lt;0.5).
The Collection of Uranium from Sea Water with Hydrous Metal Oxide. II. The Mechanism of Uranium Adsorption on Hydrous Titanium(IV) Oxide
Authors: Yamashita Hisao , Ozawa Yoshihiro , Nakajima Fumito , Murata Toshifumi 
Published: July 2006

Abstract
The mechanism of uranium adsorption from sea water by hydrous titanium(IV) oxide was investigated. The uranium adsorption experiments were conducted using a solution containing NaCl, NaHCO3, and uranium. Thermochemical calculation showed that the tris(carbonato)dioxouranate(VI) ion [UO2(CO3)3]4− found in sea water existed in the solution at pH 8 and 25 °C. The uranium uptake varied with the pH of the solution, exhibiting a minimum value at pH 8. The enthalpy change, ΔH, and the activation energy, E, of the uranium adsorption were found to be 23.6 kJ mol−1 and 52.7 kJ mol−1 respectively. The analysis of carbonate in the adsorbent showed that the carbonate ion in [UO2(CO3)3]4− was released into the solution during the uranium adsorption. On the basis of the present experimental results, the mechanism of uranium adsorption was discussed.
The Crystal Structure of (Acetylacetonato)bis(diethylamine)palladium(II) Acetylacetonate at −170°C
Authors: Kotake Shoji , Sei Tsuyoshi , Miki Kunio , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami 
Published: July 2006

Abstract
The crystal structure of [{Pd(acac)(NHEt2)2}+(acac)−] at −170°C was determined by means of X-ray diffraction. The crystal belongs to monoclinic system: a=13.905(3), b=12.901(4), c=12.205(3) Å, β=96.28(2)°, space group I2/c with Z=4. The structure was established by the heavy atom method and refined anisotropically by the least-squares procedure; R=0.044 for 1558 non-zero reflections. Both the {Pd(acac)(NHEt2)2}+ cation and (acac)− anion lie on the crystallographic two-fold axis. The cation and anion lying on the same two-fold axis are bound together by two hydrogen bonds [N–H···O(2)=N′–H′···O(2′)=2.871(4) Å] to form an ion-pair. Two ion-pairs mutually related by the crystallographic center of symmetry make a packing unit of the crystal.
Halogenotriphenyltin(IV) Adducts of Tetrakis(t-butyl isocyanide)rhodium(I) Perchlorate. Preparation and Kinetics
Authors: Kuwae Ryosho , Tanaka Toshio 
Published: July 2006

Abstract
[Rh(t-BuNC)4]ClO4 undergoes oxidative addition reactions with Ph3SnX (X=Cl, Br) to give cis-[Rh-(Ph3Sn)X(t-BuNC)4]ClO4. The adducts partly dissociate in solution to exist as an equilibrium mixture with the Rh(I) substrate and the addendum. Kinetics of the equilibrium reactions in three different organic solvents were studied spectrophotometrically under pseudo-first-order conditions with excess Ph3SnX. Rate constants for the forward reaction (kf) are strongly dependent on the solvent polarity; kf increases in the order of 1,2-dichloroethane&lt;acetone&lt;acetonitrile, whereas those for the backward reaction are little dependent on the solvents. Activation parameters also were obtained for the X=Cl system in acetonitrile; ΔS\eweq for the forward reaction is −99.2 J mol−1 K−1, while that for the backward reaction is +24.9 J mol−1 K−1. These results indicate that the addition reactions proceed via a three-center transition state formed by the nucleophilic attack of the Rh(I) ion to the tin atom.
Chemical Studies on Tuberactinomycin. XVII. Synthesis of threo-γ-Hydroxy-l-β-lysine, Constituent Amino Acid of Tuberactinomycin A and N
Authors: Teshima Tadashi , Ando Toshihiko , Shiba Tetsuo 
Published: July 2006

Abstract
threo-γ-Hydroxy-l-β-lysine which is a constituent amino acid of antibiotics tuberactinomycin A and N, was synthesized from threo-β-hydroxy-l-ornithine derivative by the Arndt-Eistert reaction. The synthetic amino acid was identical with the natural sample in all respects. Furthermore, a route was established to prepare a protected γ-hydroxy-β-lysine derivative useful for the peptide synthesis.
The Molecular Structure of 1-Phenoxy-1,2,2a,8b-tetrahydrocyclobuta[α]naphthalene-8b-carbonitrile
Authors: Matsuura Hideaki , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami 
Published: July 2006

Abstract
The molecular structure of the sole photocycloaddition product of α-naphthonitrile with phenyl vinyl ether, C19H15ON was determined by means of X-ray diffraction. The crystals are monoclinic, space group P21/c, unit-cell dimensions are a=11.563(2), b=9.826(1), c=14.324(2) Å, β=113.46(1)°, Z=4. The structure was solved by the direct method, the final R value being 0,042 for 2022 non-zero reflections. The molecule has an endo-configuration, and the cyclobutane ring is puckered.
Infrared and ESR Spectra of Reaction Intermediates Formed from 1,1-Diphenylethylene Adsorbed on Oxides
Authors: Tani Noriko , Kawamori Asako , Yamada Haruka 
Published: July 2006

Abstract
When 1,1-diphenylethylene (DPE) was adsorbed on porous Vycor glass (PVG) or silica–alumina, some unstable reaction intermediates, blue, green, and yellow species, were formed. The blue species produced on the silica–alumina showed a characteristic band at 1525 cm−1, assigned to the shifted C=C stretching band, which disappeared in the green and yellow samples; it also showed an ESR signal. This indicates that the unstable blue species is probably a cation radical (Remark: Graphics omitted.). The infrared spectra of the green and yellow species on the silica–alumina showed new bands, ascribed to the –CH3 and –CH2– vibrations, which were in good agreement with the resonance Raman bands of the carbonium ions formed on the PVG. The green and yellow intermediates, therefore, should be two kinds of carbonium ions. The structures, formation mechanisms, and surface coverages of these intermediates are discussed.
The Modification of Tryptophyl Residues during the Acidolytic Cleavage of Boc-groups. I. Studies with Boc-Tryptophan
Authors: Masui Yoshihiro , Chino Naoyoshi , Sakakibara Shumpei 
Published: July 2006

Abstract
The formation of a component, X, was observed when a reaction mixture of t-butyloxycarbonyl-tryptophan (Boc-Trp), trifluoroacetic acid (TFA), and 1,2-ethanedithiol was analyzed by cellulose TLC. The side product was isolated and further separated into two components by column chromatography on silica gel. The subsequent analysis of the NMR spectra of these components confirmed that they were Nin-But-Trp and Cin-But-Trp. The reaction of Boc-Trp with TFA and with anhydrous hydrogen fluoride (HF) was examined as model systems in order to determine conditions which would minimize the formation of the X component during the synthesis of peptides containing Trp. The addition of 10 molar equivalents of 1,2-ethanedithiol completely suppressed the formation of the X component in HF, but additives were less efficient in TFA. A combination of dimethyl sulfide and 1,2-ethanedithiol was the most effective method for suppressing the formation of the X component in TFA. The behavior of Nin- and Cin-But-Trp in acidic media was also investigated, and a possible pathway for the t-butylation of the tryptophyl residue will be proposed.
13C-NMR Study of the Solvent Effect of the N-Acetyl-l-alanine Methyl Ester
Authors: Asakura Tetsuo , Nishioka Atsuo 
Published: July 2006

Abstract
The 13C-NMR spectra of the N-acetyl-l-alanine methyl ester in solution were observed in order to clarity the solvent effect. The assignment of the two kinds of carbonyl groups was carried out on the basis of the difference in the long-range 1H–13C coupling patterns and the spectral change through the hydrolysis of the ester group in a D2O solution. The internal rotational angle around the N–Cα bond was estimated as −94° from the observed value of 3JC′−N−C″−H, using Bystrov equation. In a trifiuoroacetic acid solution, the formation of strong hydrogen bonds accompanying partial protonation between the N-acetyl-l-alanine methyl ester and the solvent was suggested. Moreover, the acetyl C=O group tends to interact with trifiuoroacetic acid more strongly than the alanyl C=O group.
Phenanthro[4,5-bcd]furan Derivatives. VI. Some Electrophilic Substitution Reactions and Hydrogenation of 4H-Cyclopenta[def]phenanthrene, Phenanthro[4,5-bcd]furan, and 4H-Benzo[def]carbazole
Authors: Horaguchi Takaaki , Yamazaki Reiko , Abe Teishiro 
Published: July 2006

Abstract
Some electrophilic substitution reactions and hydrogenation of 4H-cyclopenta[def]phenanthrene (1a), phenanthro[4,5-bcd]furan (1b), and 4H-benzo[def]carbazole (1c) have been investigated. The bromination of 1a and 1b with bromine gave the corresponding 8-bromo derivatives. The bromination of 1c however gave the 1,3,5,7-tetrabromo derivative as the sole product. The benzoylation of 1a and 1b afforded the corresponding 1-benzoyl derivatives, but in the case of 1c, the 1,7-dibenzoyl derivative was obtained together with the 4-benzoyl derivative. It appears that ortho- and para-orientation of the nitrogen atom in 1c is much stronger than that of the methylene group or the oxygen atom in 1a or 1b. Hydrogenation of 1a, 1b, and 1c with palladium–charcoal catalyst afforded the corresponding 8,9-dihydro derivatives (4a, 4b, and 4c). The reduction of 1a and 1c with sodium–ethanol gave 4a and 4c. The reduction of 1b however gave the 3,3a,8,9,9a,9b-hexahydro derivative. It appears that facile hydrogenation of the carbon-carbon double bonds at the 8,9-positions in 1a, 1b, and 1c are due to strain in the fused ring system.
Layered Compounds. LXII. Triple-layered [m.m][n.n]Paracyclophanes: Syntheses and Spectra
Authors: Otsubo Tetsuo , Kohda Takashi , Misumi Soichi 
Published: July 2006

Abstract
A series of the title cyclophanes (m, n=2–4) were synthesized by the thermal- and photo-desulfurization methods from dithia intermediates. Their absorption and emission spectra were measured to examine the transannular electronic interaction. The absorption spectra of the title compounds and their TCNE complexes gave the same order of the interaction as seen in the case of double-layered system: [2.2]&gt;[3.3]&gt;[4.4] in neutral state and [3.3]&gt;[2.2]&gt;[4.4] in CT state. The emission spectra are discussed in terms of the existence of excited trimer.
Photocyclization of 2′-Hydroxychalcones to 4-Flavanones
Authors: Matsushima Ryoka , Hirao Ichiro 
Published: July 2006

Abstract
On irradiation with light of λ≥365 nm, parent and methoxy-substituted 2′-hydroxychalcones undergo facile photocyclization to give corresponding 4-flavanones in high efficiencies in ethyl acetate or dioxane, whereas in low or nil efficiencies in benzene, chloroform, carbon tetrachloride, ether, acetonitrile, ethanol, or t-butyl alcohol. The low reactivity in benzene is, however, significantly increased by the addition of liquid paraffin to increase the solvent viscosity. 3′,4′-Benzo-2′-hydroxychalcone showed low reactivities in any solvents. The formation of 4-flavanones is neither quenched by triplet quenchers nor depressed by the addition of free radical scavengers. The reaction mechanism is discussed in terms of enolization.
Phenyl- and Tolylthallium(III) Bis(trichloroacetate)s; Preparation and Reactions
Authors: Uemura Sakae , Miyoshi Haruo , Wakasugi Mikio , Okano Masaya , Itoh Osamu , Izumi Takaaki , Ichikawa Katsuhiko 
Published: July 2006

Abstract
Phenyl- and tolylthallium(III) bis(trichloroacetate)s [ArTl(OCOCCl3)2, 1 (Ar=phenyl or tolyl)] were prepared from thallium(III) oxide, trichloroacetic acid, benzene, and toluene. The replacement of the thallium moiety in 1 with iodo, chloro, cyano, selenocyanato, and nitro groups and the aromatic coupling of 1 proceeded smoothly to give the corresponding aromatic derivatives in good yields. In the presence of PdCl2-NaOAc, 1 (Ar=phenyl) reacted with acrylonitrile and methacrylonitrile to afford cinnamonitriles(trans and cis) and a mixture of α-benzylacrylonitrile and β-phenylmethacrylonitriles(Z and E) respectively.
Studies on the Tautomerism of 2-Anilinopyridine and Related Heterocycles. II. 2-Anilino-5-nitropyridine and 2-Anilinopyrimidine
Authors: Hirota Minoru , Sekiya Toshiyuki , Hishikura Akira , Endo Hiroko , Hamada Yoshiki , Ito Yoshio 
Published: July 2006

Abstract
The tautomeric behavior of 5-nitro-2-anilinopyridine and 2-anilinopyrimidine was studied. 2-(N-Methylanilino) and l-methyl-2-(phenylimino)-1,2-dihydro derivatives were prepared as models for the amino and imino tautomers, respectively, and their spectra were compared. The results and the assumed tautomeric equilibrium constants strongly suggest the equilibria to be favorable to the amino tautomers, the Kt values being considerably smaller than that of the parent 2-anilinopyridine.
Photo-cycloaddition of Indene to Chlorofluoroethylenes and Some Reactions Concerning the Adducts
Authors: Kimoto Hiroshi , Takahashi Kensuke , Muramatsu Hiroshige 
Published: July 2006

Abstract
Benzophenone photo-sensitized addition of indene to chlorofluoroethylenes [trichlorofluoroethylene, 1,2-dichloro-1,2-difluoroethylene, 1,1-dichloro-2,2-difluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene] afforded 6,6,7,7-tetrahalogeno-2,3-benzobicyclo[3.2.0]hept-2-enes as corresponding cycloadducts. The structure of the cycloadducts obtained from unsymmetrical chlorofluoroethylenes shows that the addition reaction proceeds with good regioselectivity. Some reactions such as oxidation, reduction, dechlorination, and halogenation of the cycloadducts were also examined.
The Crystal Strycture of the β From of p-Chlorobenzamide
Authors: Hayashi Taiichi , Nakata Kazuaki , Takaki Yoshito , Sakurai Kiichi 
Published: July 2006

Abstract
The crystal of the title compound is monoclinic with space group P21/a, a=9.11, b=9.54, c=8.18 Å, β=93.8°, Z=4. The structure was solved by a packing analysis based on an ellipsoid-model and refined by block-diagonal least-squares calculations to R=0.115. The amide group makes a dihedral angle of 2.0° with the benzene ring.
An ESR Study of Hydrogen Atoms in Methane–Air Flame
Authors: Noda Shoji , Miura Masazumi , Yoshida Hiroshi 
Published: July 2006

Abstract
In order to give a basis for the utilization of ESR in combustion chemical studies, both diffusion flames and premixed flames of a methane–air mixture have been studied by the flame-in-cavity ESR method. A pair of spectral lines separated by 51.0 mT due to H atoms and a very weak single line due to unidentified reaction intermediates have been recorded from combusting gases in a modified Bunsen burner. The H atoms in the diffusion flame give the spectral linewidth of 0.15 mT and populate a confined region near the luminous cone. In the premixed flame, the H atom concentration is the highest at the outside of the luminous inner cone (reaction zone), but it is distributed as long as 4 cm along the gas stream. The profile of the local concentration has been obtained by the deconvolution method from the observed dependence of the spectral intensity on the location of the flame in the resonant cavity. The maximum concentration can be estimated to be 2.4×1015 atoms/cm3, which is much higher than the equilibrium concentration calculated from the flame temperature. 1200 K, and the oxygen excess ratio, 0.67. The spectral linewidth (0.01–0.04 mT) and the microwave power saturation of the H atoms depend on the location in the flame. These results strongly suggest that the line broadening and the spin relaxation are principally determined by the collision between the H atoms and the molecular oxygen.
Thermochemical Studies on Double- and Triple-layered [2.2]Paracyclophanes. Estimation of Molecular Strain Energies.
Authors: Nishiyama Keiichi , Sakiyama Ninoru , Seki Syûzô , Horita Hisanori , Otsubo Tetsuo , Misumi Soichi 
Published: July 2006

Abstract
The measurements of enthalpies of combustion by use of precision oxygen-bomb combustion calorimeter together with the measurement of carbon dioxide recovery were made for double- and triple-layered [2.2]paracyclophanes. The enthalpies of sublimation were also determined by the measurement of temperature dependence of the vapor pressures for the two compounds. The following values are reported for the standard enthalpy of combustion ΔHco(298.15 K)/kJ mol−1 and standard enthalpy of sublimation ΔHso(298.15 K)/kJ mol−1, respectively: double-layered [2.2]paracyclophane, 8729.48±1.80, 99.6±1.8; triple-layered [2.2]paracyclophane, 14230.87±3.59, 125.9±2.5. From analyses of the derived standard enthalpy of formation in gaseous state the following two values for total strain energy Us⁄kJ mol−1 of a molecule of triple-layered [2.2]paracyclophane were obtained: 251.9±5.6 with group method and 245.6±9.8 with chemical similarity method, respectively. These values are approximately twice the magnitudes of the corresponding quantities for double-layered [2.2]paracyclophane. From the analysis of the total strain energy by use of the result of Boyd’s molecular mechanical calculation, the contribution from the twisting of the inner benzene ring to the total strain energy of triple-layered [2.2]paracyclophane was estimated to be almost twice that from one outer bent benzene ring.