bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Hydrocracking of Solvent Refined Coals over Molten Salt Catalysts
Authors: Nakatsuji Yohji , Ikkaku Yasuhiko , Nomura Masakatsu , Kikkawa Sh\={o}ichi 
Published: July 2006

Abstract
The hydrocracking of Y\barubari SRC and Tempoku SRC over ZnCl2/CuCl or ZnCl2 molten salt was examined at 350 or 400 °C for 3 h in a batch autoclave system. The reactivity of SRC under the hydrocracking conditions with the molten salts was estimated mainly by comparison with the results obtained in the study using a variety of polynuclear aromatic hydrocarbons. The presence of hetero atoms (especially, the hydroxyl group) in SRC may be supposed to play an important role in this hydrocracking using molten salts. In addition, the average structures of SRC, according to the GAMSG method, are offered, and the usefulness is examined from the point of view of the reactivity of SRC in the presence of molten salts.
NQR and NMR Studies of Boron Trihalide–Trimethylamine Complexes
Authors: Okuda Tsutomu , Ishihara Hideta , Yamada Koji , Negita Hisao 
Published: July 2006

Abstract
The character of the B–X bond (X=Cl, Br, and I) in BX3–TMA complexes (TMA=trimethylamine) has been studied on the basis of the results of the nuclear quadrupole resonance (NQR). The ionic character of the B–X bond decreased in the order as expected from the electronegativity of the halogen atoms. The temperature dependence of the halogens on the NQR frequencies has been examined for BBr3– and BI3–TMA. For BBr3–TMA, all the observed resonance lines faded out far below the melting point and this has been attributed to the hindered rotation of the BBr3 group about the B–N bond, as with BCl3–TMA.
Oxidation of Benzaldehydes by Peroxomonophosphoric Acid. A Kinetic and Mechanistic Study in Acid and Alkaline Media
Authors: Panigrahi G P , Panda Radhasyam 
Published: July 2006

Abstract
The oxidation of benzaldehydes by peroxomonophosphoric acid has been found to proceed by
(i) −d[peroxomonophosphoric acid]⁄dt∝ [benzaldehyde][peroxomonophosphoric acid][H+]x
where x=a fraction at [H+]&lt;0.5 M and x=0 at [H+]&gt;0.5 M and
(ii) −d[peroxomonophosphate]⁄dt∝ [benzaldehyde][peroxomonophosphate][OH−]y
where y=a fraction at [OH−]&lt;0.1 M and y=0 at [OH−]&gt;0.1 M.
In the alkaline oxidation Hammett relationship is obeyed excellently, unlike the oxidation in the acid medium. The oxidation mechanisms are discussed in terms of a nucleophilic attack of the peroxomonophosphoric acid species on the carbonyl carbon centre. Thermodynamic parameters have been evaluated to substantiate the mechanisms.
Phase Transition of [(C6H5)3PCH3]1−x+ [(C6H5)3AsCH3]x+ (TCNQ)2\ewdot, (0≤x≤1), Anion Radical Salts. Thermodynamical Stability of the Solid Solutions
Authors: Iida Yôichi 
Published: July 2006

Abstract
The phase transition and the thermodynamic properties of solid solutions were studied with anion radical salts of [(C6H5)3PCH3]1−x+ [(C6H5)3AsCH3]x+ (TCNQ)2\ewdot, (0≤x≤1). The stability condition of the solid solutions was examined in both the low- and high-temperature phases.
Proton Magnetic Relaxation Study of Oxalic Acid Dihydrate
Authors: Chiba Takehiko 
Published: July 2006

Abstract
Proton magnetic relaxation times T1, T1ρ, and T1D were measured on a single crystal of α-form oxalic acid dihydrate in two modes: temperature dependence at one or two specific crystal orientations, and angular dependence at several temperatures. Results were compared with the calculation based on an isolated three proton system for the assumed modes of motions. The temperature dependence of T1 and that of T1ρ and T1D in the low temperature range are reasonably accounted for by the 180°-flip of the water molecule. The activation energy for the motion of 43.6 kJ mol−1 is obtained. T1ρ and T1D above about 35 °C decreased as the temperature was raised. The comparison of the observed results in this temperature range with the calculated ones suggests that there is exchange motion among the three spins. An activation energy for this motion of 80.8 kj mol−1 is obtained. This three spin exchange motion may be considered as a combination of a jump of carboxyl proton to a higher potential trough corresponding to the ionic configuration and the three-fold reorientation of the hydronium ion thus formed.
The Synthesis of Crystalline Zirconium Phosphate with Large Particle Size by the Direct-precipitation Method
Authors: Inoue Yasushi , Yamada Yoshimune 
Published: July 2006

Abstract
The direct-precipitation method was studied as a possible way to synthesize crystalline zirconium phosphate of a large and uniform crystal size. The yield and the crystal size were examined as functions of the initial hydrofluoric-acid and phosphoric-acid concentrations and the warming temperature. The conditions for preparing the largest crystal were: ZrOCl2·8H2O, 0.13 M; hydrofluoric acid concentration, 0.715 M; phosphoric acid concentration, 5 M; temperature, 50 °C. Those for preparing the material with uniform crystal-size distribution and a possibly large-mean crystal size were: ZrOCl2·8H2O, 0.13 M; hydrofluoric acid concentration, 0.715 M; phosphoric acid concentration, 9 M; temperature, 60 °C. The product was confirmed to be crystalline Zr(HPO4)2·H2O by means of chemical, thermal, and X-ray analyses, and by an examination of the titration curve.
Thermodynamic Studies on Phase Transitions of Potassium Thiocyanate and Ammonium Thiocyanate Crystals
Authors: Kinsho Yoshio , Onodera Natsuo , Sakiyama Minoru , Seki Syûzô 
Published: July 2006

Abstract
Heat capacities of KSCN and NH4SCN crystals were measured by adiabatic calorimetry in the temperature range between 13 K and the melting points. Molar volume of NH4SCN was also determined above room temperature. Entropy change for the II-I transition of KSCN (414.54 K, essentially higher order but accompanied with the first order component) is 6.26 J K−1 mol−1 (=1.09 R In 2), which is of similar magnitude with our previous value (Bull. Chem. Soc. Jpn., 36, 1025 (1963)). Entropy change for the III-II transition of NH4SCN (360.1 K,first order) is 10.01 J K−1 mol−1 and apparent entropy change for the II-I transition of NH4SCN (392.8 K, higher order) is 2.85 J K−1 mol−1 (=0.49 R In 2) in spite of possibly similar nature of the transition with the II-I transition of KSCN. A possibility has been suggested that the entropy change might be approximately R In 2 if the transition was not interfered with the III-II trasition and the premelting.
A Study of the Ligand Exchange Reaction of Tetrakis(μ-trifluoroacetato)dimolybdenum(II) in Acetonitrile by 19F NMR Spectroscopy
Authors: Teramoto Kazunori , Sasaki Yoichi , Migita Kouto , Iwaizumi Masamoto , Saito Kazuo 
Published: July 2006

Abstract
The dimeric molybdenum(II) complex, Mo2(CF3COO)4, forms Mo2(CF3COO)4·(CH3CN)2 in acetonitrile, where solvent molecules are attached to positions trans to the metal–metal bond (apical positions). The rate of ligand exchange between Mo2(CF3COO)4 ((1.31–8.28)×10−2 M; M=mol dm−3) and CF3COONa ((1.31–4.56)×10−1 M) was measured in acetonitrile by the use of 19F NMR spectroscopy. The rate is independent of the total concentration of CF3COONa and is linearly dependent on that of Mo2(CF3COO)4. The first-order rate constant (kex) is (1.1±0.2)×104 s−1 (25 °C), and the activation parameters are ΔH\eweq=(8.2±0.8) kcal mol−1 and ΔS\eweq=(−15±3) K−1 mol−1. Under the given conditions the complex seems to exist as Mo2(CF3COO)4·CF3COO−, where the underlined ligand occupies one of the apical positions, and the following mechanism is proposed (solvent molecules are omitted; asterisks indicate the molecule substituting for the coordinated ligand).
Mo2(CF3COO)4·CF3COO−+*CF3COO−\oversetfast\ightleftarrowsMo2(CF3COO)4·*CF3COO−+CF3COO−
Mo2(CF3COO)4·*CF3COO−\oversetks→Mo2(CF3COO)3(*CF3COO)·CF3COO−
The kex corresponds to ks.
Thermal Decomposition of Coal-related Aromatic Compounds in Hydrogen-donating Solvent
Authors: Yao Tadashi , Kamiya Yoshio 
Published: July 2006

Abstract
In order to elucidate the reaction mechanism of coal dissolution in the hydrogen-donating solvent, twenty aromatic compounds related to coal were treated at 450 °C in the presence of tetralin. Diphenylmethane and bibenzyl slowly decomposed giving alkylbenzenes almost quantitatively. Diphenylmethanol and benzophenone were hydrogenated to diphenylmethane, and benzyl phenyl ketone to a mixture of diphenylmethane and bibenzyl. Diphenyl ether and dibenzofuran are very stable, di-2-naphthyl ether decomposing slowly and benzyl phenyl ether or dibenzyl ether very rapidly. The conversion of aromatic compounds by thermolysis can be correlated as a function of bond dissociation energy. The bond rupture of coal-related polynuclear aromatic compounds at 450 °C was concluded to occur mainly at methylene or ether structures. Addition of phenolic compounds or quinoline is very effective for the decomposition of di-2-naphthyl ether. The effect of phenolic compounds and quinoline on the thermal decomposition of aromatic ether was discussed on the basis of stabilization of transition state due to solvation.
Spectroscopic Studies of Solvent Effects on Intramolecular Hydrogen Bonding in N-Substituted Salicylamides
Authors: Kondo Michio 
Published: July 2006

Abstract
It has been found from absorption and emission spectra that the intramolecular hydrogen bonds between the phenolic hydroxyl and carbonyl group of N-methylsalicylamide and N-methyl-5-chlorosalicylamide survive in DMSO as well as in 1,2-dichloroethane, whereas those of N,N-dimethylsalicylamide and N,N-dimethyl-5-chlorosalicylamide are disrupted in DMSO. The solvent dependence of the 1H and 13C chemical shifts of these compounds are also well related to the intramolecular hydrogen bonding.
Light-induced Conformational Changes of Polypeptides. Photoisomerization of Azoaromatic Polypeptides
Authors: Ueno Akihiko , Anzai Jun-ichi , Osa Tetsuo , Kadoma Yoshinori 
Published: July 2006

Abstract
Copolymers of β-benzyl l-aspartate with β-m- or p-(phenylazo)benzyl l-aspartate were prepared in order to investigate the effect of side-chain photoisomerization on their conformations. These polymers in 1,2-dichloroethane show a CD band at 222 nm characteristic of left-handed α-helices. After irradiation, remarkable changes of the 222 nm band were observed for both meta and para copolymers with more than 50 % azo residues. The decrease in ellipticity observed for the meta copolymers indicates that photoisomerization induces a significant instability in the left-handed α-helical conformation. On the other hand, the para copolymers change their sign from positive to negative by irradiation, confirming the reversal in the helix sense. In the course of subsequent relaxation of the irradiated para copolymer with 59% azo residues, an abrupt change in the CD spectra was found above 50% cis followed by a gradual change on decreasing the content of cis isomers. Concerning the polymers with azoaromatic side chains including copolymers with γ-benzyl l-glutamate, the helical sense seems to affect appreciably the sign of the side-chain CD bands.
Photochemical Thiocyanation of Halobenzenes with Thiocyanate Anion
Authors: Fujiki Kiyoko , Nishio Takehiko , Omote Yoshimori 
Published: July 2006

Abstract
Halobenzenes having such an electrondonating group as amino, hydroxyl or methoxyl group at their para position were thiocyanated with sodium thiocyanate under irradiation. Also, the ring isomer of o-thiocyanatoaniline, 2-aminobenzothiazole, was obtained by the photoreaction of o-chloroaniline with sodium thiocyanate.
Oxidation of Organic Compounds with Perborates or H2O2–Boric Acids
Authors: Ogata Yoshiro , Shimizu Hideo 
Published: July 2006

Abstract
Perborate oxidation of p-chloroaniline to 4,4′-dichloroazobenzene and H2O2–boric acid hydroxylation of aromatics have been studied. The kinetic behavior suggests that the so-called sodium perborate is not peroxoborate but borate peroxyhydrate, H2O2 acquiring stronger electrophilicity by the coordination with boric acid which acts as Lewis acid rather than protic acid.
The Reaction of 1-(1-Pyrrolidinyl)acenaphthylene with Electrophilic Acetylenes
Authors: Tsuge Otohiko , Watanabe Haruyuki 
Published: July 2006

Abstract
1-(1-Pyrrolidinyl) acenaphthyIene (1), which was prepared from acenaphthenone and pyrrolidine, reacted with dimethyl acetylenedicarboxylate to give the dihydrocyclohepta[de]naphthalene and dihydrofluoranthene. The reaction of 1 with methyl propiolate in benzene afforded the dihydrocyclohepta[de] naphthalene (8) and its isomeric cyclohepta[denaphthalenol (9), whereas the Michael type adduct was formed in methanol. An interconversion between 8 and 9 was also described.
A Novel Synthesis of δ-Amino Acid Derivatives
Authors: Imagawa Takeshi , Kawanisi Mituyosi 
Published: July 2006

Abstract
The Diels-Alder adducts of “anhydrochloral-urethane” with some 1,3-dienes were successfully utilized for the synthesis of some δ-amino acid derivatives by the sequence of the reactions, viz., hydrogenation, dehydrochlorination, and ozonolysis.
Absorption and Fluorescence Spectra of Anthracenecarboxylic Acids. II. 1- and 2-Anthroic Acids
Authors: Suzuki Satoshi , Fujii Tsuneo , Yamanaka Shigeru , Yoshiike Nobuyuki , Hayashi Zenro 
Published: July 2006

Abstract
The absorption and fluorescence spectra of 1- and 2-anthroic acids (1- and 2-anthracenecarboxylic acids) in alcoholic solvents have been observed as a function of solute concentration. It was revealed that 1- and 2-anthroic acids form hydrogen-bonded dimers in their ground states. The equilibrium constants for dimer formation are : 1.2×104 mol−11 for 1-anthroic acid in methanol and 2.0×104 mol−11 for 2-anthroic acid in ethanol. Owing to dimer formation, the lowest frequency absorption band of 1-anthroic acid was uniformly displaced to the red, while that of 2-anthroic acid was distinctly resolved into two bands. The band assignment was confirmed by the method of photoselection. No excimer-type fluorescence was observed in 1- and 2-anthroic acids. The lack of mirror-symmetry relationship between the absorption and fluorescence spectra of 1-anthroic acid is explained by the geometrical relaxation in its excited state.
Thermochromism of Metal Chelates with Triphenylmethane Complexons in Aqueous Solutions. I. Copper(II)–Xylenol Orange System
Authors: Nakada Shoji , Yamada Mutsuo , Ito Tasuku , Fujimoto Masatoshi 
Published: July 2006

Abstract
Reversible thermochromisms are found for about thirty kinds of metal complexes of triphenylmethane complexons in aqueous solutions. The thermochromism observed in the aqueous solution of copper(II) complex with 3,3′-bis[N,N-bis(carboxymethyl)aminomethyl]-o-cresolsulfonphthalein (Xylenol Orange, XO) was primarily ascribed to the temperature-dependence of the protolytic equilibria between a complex species AH having an uncoordinated free phenolic hydroxyl group and a complex species A having a coordinated phenolate group: AH\ightleftharpoonsA+H. The equilibrium constant K of the reaction was determined to be p(K/mol dm−3)=4.40 at 25 °C. The thermodynamic parameters ΔH and ΔS for the reaction were calculated to be 26±2 kJ mol−1 and 1±3 J mol−1 K−1 (298 K), respectively. The rate constant of the proton dissociation of the phenolic hydroxyl group in the complex AH was estimated to be ca. 2±105s−1.
Metal Complexes of Amino Acids. XI. Preparation and 13C NMR Spectra of the Cobalt(III) Complexes Containing β-Alanine and Glycine
Authors: Ama Tomoharu , Yasui Takaji 
Published: July 2006

Abstract
A series of complexes or geometrical isomers, [Co(β-ala or gly)(en)2]2+, [Co(β-ala or gly)2(en)]+, [Co(β-ala or gly)(ox)2]2−, and [Co(β-ala or gly)2(ox)]−, were prepared and their 13C NMR spectra were measured. Assignments of their structures and 13C NMR signals were made. The β-alaninate carbons in the complexes resonate at 33.6±0.5, 38.3±0.6, and 183.0±1.5 ppm and the glycinate carbons at 46.3±1.3 and 187.4±1.4 ppm. The 13C chemical shifts of the mixed (β-alaninato)(glycinato) complexes consist of those of the corresponding isomers of bis(β-alaninato) and bis(glycinato) complexes.
Luminescence Spectra of Cobalt(III) Cyano Complexes
Authors: Yamamoto Yusuke 
Published: July 2006

Abstract
Luminescence spectra of M3[Co(CN)6] (M=K, Rb, Cs), cis-K3Na2[Co(CN)4(SO3)2], and trans-Na5[Co(CN)4(SO3)2] were measured at 20 K. Single crystal luminescence spectra of the hexacyanocobaltates(III), centered at 14100–14200 cm−1, exhibited vibrational structure associated with three components, and the separation between the members of the progression was about 400 cm−1. Luminescence spectra of powdered cis-K3Na2[Co(CN)4(SO3)2] and trans-Na5[Co(CN)4(SO3)2] were structureless and broad centered at 13200 and 14400 cm−1, respectively. Comparison of these luminescence spectra with the corresponding spin-forbidden bands indicated that the 0-0 transition lies at 18300–18600 cm−1 for hexacyanocobaltates(III), at 16500–17000 cm−1 for cis-K3Na2[Co(CN)4(SO3)2], and at 17700–18200 cm−1 for trans-Na5[Co(CN)4(SO3)2]. The vibrational structure in luminescence spectra of hexacyanocobaltates(III) can be interpreted in terms of the ν8,ν9,ν12 and ν13 ungerade skeletal modes, a lattice mode, and the totally symmetric ν2 vibrational mode. Analysis of the relative intensity of the vibrational structure in the luminescence spectra gave information about the change in the Co–C internuclear equilibrium distance from the ground state to the excited luminescent state. The relationship between luminescence and photochemical behavior of cobalt(III) complexes was also considered.
The Relative Rate Constants of Reactions of Oxygen Atoms with Several Olefins in Liquid Carbon Dioxide
Authors: Karasawa Hidetoshi , Sasamoto Tai , Yugeta Rei , Sato Shin 
Published: July 2006

Abstract
The relative rate constants of reactions of oxygen atoms with several olefins and 2-methylpropane have been determined in liquid carbon dioxide at −18 °C, using the γ-radiolysis of carbon dioxide in the presence of these hydrocarbons. They are : 1-butene, 1.0; cis-2-butene, 2.3; trans-2-butene, 3.0; 2-methylpropene, 2.9; 2,3-dimethyl-2-butene, 2.0; 2-methylpropane, 0.07. These relative values are very different from those obtained in the gas phase. A possible reason is discussed and a simple theoretical treatment is proposed for the competition between diffusion and reaction on the basis of the idea of a “collision set” in the liquid phase. The reaction of oxygen atoms with paraffin in liquid carbon dioxide seems to be faster than that in the gas phase. The reason is not clear at present.
Formation of Micelles of Hexadecyltrimethylammonium Bromide in Water-N,N-Dimethylformamide Solutions
Authors: Ionescu Lavinel G , Tokuhiro Tadashi , Czerniawski Benjamin J 
Published: July 2006

Abstract
The critical micellar concentration of aqueous solutions of hexadecyltrimethylammonium bromide (HTAB) containing various amounts of N,N-dimethylformamide (DMF) has been determined at 25 and 40 °C by means of surface tensiometric measurements. The standard free energy (ΔGm°), enthalpy (ΔHm°) and entropy (ΔSm°) of micellization were also determined. The experimental results indicate that: (1) micelle formation is somewhat hindered by a raise in temperature, and (2) DMF has an inhibitory effect on the formation of micelles of HTAB. This effect is relatively small at low DMF concentrations, but it increases drastically as the mole fraction of DMF approaches 0.33. The changes in the ΔGm°, ΔHm°, and ΔSm° values indicate that the formation of HTAB micelles in the water-DMF mixtures is an entropy directed process at lower concentrations of DMF and the inhibitory effect of DMF on micelle formation is attributed to an increase in the orderliness of this system with increasing DMF concentration.
The Modified Wurtz Reaction Using Tetrakis(p-dimethylaminophenyl)ethylene
Authors: Miyahara Yuji , Shiraishi Takanari , Inazu Takahiko , Yoshino Tamotsu 
Published: July 2006

Abstract
The Wurtz reaction has been found to be catalyzed by easily removable tetrakis(p-dimethylaminophenyl)ethylene. This modification facilitated the separation of products in the syntheses of [2.1.2.1.]-, [2.2.2.2]-, and [3.2.3.2]paracyclophanes, the isolated yields of which were better than in the case of tetraphenylethylene.
Photochemical Formation of Tetrahydro-2-furyl Ether in Alcohol-Tetrahydrofuran-Iron(III) Chloride System
Authors: Kurokawa Hideo , Ishigami Tatsuzo , Morimoto Katsuaki , Sugimori Akira 
Published: July 2006

Abstract
Primary and secondary alcohols are converted into the corresponding tetrahydro-2-furyl ethers upon UV- and solar irradiation of alcohol and tetrahydrofuran in the presence of iron(III) chloride.
Synthetic Photochemistry. XIII. Chiroptical Retention for the Reported “antara-antara”-3,3-Sigmatropy of Bicyclo[3.2.0]hepta-3,6-dien-2-ones
Authors: Takeshita Hitoshi , Kumamoto Masatoshi , Kouno Isao 
Published: July 2006

Abstract
Troponoids were shown to form 2:1-complexes with β-cyclodextrin and 1:1-complexes with α-cyclodextrin. The photoisomerization of complexed tropolone and 2-methoxytropone gave optically active 1-hydroxy- and 1-methoxybicyclo[3.2.0]hepta-3,6-dien-2-ones in improved yields. The pyrolysis of the (+)-1-methoxybicyclo[3.2.0]hepta-3,6-dien-2-one gave the (+)-3-methoxybicyclo[3.2.0]hepta-3,6-dien-2-one, ruling out the two-fold supra-antara-1,3-sigmatropy.
The Synthesis of Benzofuroquinolines. II. Two Benzofuroquinolinones and Some Benzofuroquinoline Derivatives
Authors: Kawase Yoshiyuki , Yamaguchi Seiji , Morita Mariko , Uesugi Taeko 
Published: July 2006

Abstract
Two benzofuroquinolinones, 6,11-dihydrobenzofuro[2,3-b]quinolin-11-one and 5,6-dihydrobenzofuro[3,2-c]quinolin-6-one, were obtained by the demethyl-cyclization of 4-hydroxy-3-(o-methoxyphenyl)-1,2-dihydroquinolin-2-one. The chlorination of these benzofuroquinolinones afforded the corresponding chlorobenzofuroquinolines which were then converted to the cyanobenzofuroquinolines. The linear chlorobenzofuroquinoline was converted to 11-methoxy- and 11-ethoxybenzofuro[2,3-c]quinolines, and the linear cyanobenzofuroquinoline to benzofuro[2,3-b]quinoline-11-carboxylic acid and -11-carboxamide. The linear benzofuroquinolines thus obtained were oxidized to the corresponding N-oxides.
Thermodynamic Relation of Interfacial Tensions in Three Fluid Phases
Authors: Tajima Kazuo , Tsutsui Takao , Murata Hiroshi 
Published: July 2006

Abstract
The thermodynamic relation was derived for the interfacial tensions at the three interfaces of two immiscible solutions and their vapor phase at a constant temperature. The relation obtained was experimentally tested by measuring each interfacial tension of systems which consisted of organic (alcohols(C4–C10), triolein, and hexadecane) and aqueous phases. The relation of the interfacial tensions was valid for the polar oil–water systems, but not for the hexadecane–water system unless a surfactant was added.
The Partial Molar Quantity of the Sulfur of the Compounds in the Fe–V–S System
Authors: Wada Hiroaki 
Published: July 2006

Abstract
An equilibrium study of the Fe–V–S system was carried out under controlled sulfur-pressure conditions. Partial molar enthalpies of the sulfur of the compounds in the Fe–V–S system were calculated on the basis of the Ps2–T–X relations, which were established at temperatures between 520 and 814 °C.