bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Chelate Formation of (o-Substituted Phenylazo)chromotropic Acids with Alkaline Earth Metals. II
Authors: Katayama Takeshi , Miyata Haruo , Tôei Kyoji 
Published: July 2006

Abstract
The acid dissociation constants of phenylazochromotropic acid and its o-substituted derivatives with -CH3, -OCH3, -COCH3, -COOH, -CH2COOH, -COCOOH, -OCH2COOH, and -CH(OH)COOH in the ortho position to the azo group, and the stability constants of their 1 : 1 metal chelates with alkaline earth metals have been measured by potentiometric titation. The measurements have been carried out at 25°C and at μ=0.10 with KNO3. The effects of these substituents on the acid dissociation constants of the reagents and on the stability constants of these chelates were discussed. The pKa value for the naphtholic proton of the o-substituted reagents was larger than that of phenylazochromotropic acid, and the stability constants of these chelates with alkaline earth metals decreased as follows: Mg&gt;Ca&gt;Sr&gt;Ba, while for the chelates of the o-OCH2COOH reagent the order was Ca&gt;Mg&gt;Sr&gt;Ba, and for the o-CH(OH)COOH reagent it was Mg≈Ca&gt;Sr&gt;Ba. The plots of the stability constants, log K1 against the sum of the acid dissociation constants, pKA(=pKa1+pKa2), were approximately linear except for the above two reagents with calcium, strontium, and barium. From the results obtained, the o-OCH2COOH reagent that behaves as a quadridentate ligand forms a more stable chelate with calcium, strontium, and barium, and the effect of the -OCH2COOH group, especially that of the coordination of the -O- atom, is remarkable in its calcium chelate.
The 3020-cm−1 Band in the Infrared Absorption Spectra of Methyl Esters of Unsaturated Higher Fatty Acids
Authors: Hirabayashi Yoshio , Kato Nobukatsu , Mizuta Masateru , Ishihara Hideharu 
Published: July 2006

Abstract
Studies were made of the infrared absorption spectra of methyl esters of oleic, elaidic, linoleic, linoelaidic, trans-10, cis-12-octadecadienoic, α-eleostearic, stearolic, stearic, 9,10-dideutero-oleic, and 9,10-dideutero-elaidic acids in the C–H stretching region. It was further confirmed that the prominent absorption bands at 3020 cm−1 occurring in the infrared absorption spectra of methyl esters of unsaturated higher fatty acids are assignable to the =C–H stretching vibrations of a cis-ethylenic double bond. The =C–D stretching vibrations of deuteroethylenic double bonds (–CD=CD–) in methyl 9,10-dideutero-oleate and -elaidate occurred at 2250 and 2225 cm−1 respectively.
The Stereochemistry of the Reduction of 2-Substituted Cyclopentanones with Complex Aluminum Hydrides
Authors: Senda Yasuhisa , Mitsui Sekio , Ono Ryuko , Hosokawa Shizuo 
Published: July 2006

Abstract
Five different 2-substituted cyclopentanones have been reduced by complex aluminum hydrides in various solvents. In the lithium aluminum hydride reduction, the proportion of cis 2-substituted cyclopentanols tends to increase with the steric bulkiness of the substituent. The fact that the composition of the products changes with the sort of solvent is discussed in terms of the difference in the coordinating abilities of the solvents. More cis 2-substituted cyclopentanols are obtained by lithium trimethoxyaluminum hydride than by the other complex aluminum hydrides used in the present study. Lithium tri-t-butoxyaluminum hydride and lithium aluminum hydride-aluminum chloride reduction are also investigated.
Synthesis and Decomposition of Alkane- and Arenesulfonyl Aryl Disulfides
Authors: Abe Yasuo , Nakabayashi Takeshige , Tsurugi Jitsuo 
Published: July 2006

Abstract
Pyridinium alkane- and arenethiolsulfonates were allowed to react with arenesulfenyl chlorides, CISAr′, to yield sulfonyl disulfides in which R is n-dodecyl, benzyl, phenyl, or p-tolyl group, and Ar′ o-nitrophenyl or o-nitro-p-chlorophenyl. p-Toluenesulfonyl p-nitrophenyl disulfide was also prepared by this method. IR and UV spectra of these compounds were determined and compared with those of the corresponding thiolsulfonates. Decomposition of 35S-labeled p-toluenesulfonyl p-nitrophenyl disulfide, p-CH3C6H4SO2S35SC6H4NO2-p, gave 35S-labeled p-nitrophenyl p-toluenethiolsulfonate, p-CH3C6H4SO235SC6H4NO2-p. Triphenylphosphine was found to attack two oxygen atoms and a sulfur atom of p-toluenesulfonyl o-nitrophenyl disulfide at the same rate. The reaction of triphenylphosphine with 35S-labeled p-toluenesulfonyl o- and p-nitrophenyl disulfides revealed that the central sulfur atom of these sulfonyl disulfides was desulfurated. This result coincides with that of the decomposition mentioned above. The susceptibility of sulfonyl disulfides containing p-nitrophenyl group to the decomposition and the desulfuration of the central sulfur atom of sulfonyl disulfides in general are also discussed.
The Total Synthesis of (±)-Taxodione, A Tumor Inhibitor
Authors: Matsumoto Takashi , Tachibana Yakudo , Uchida Junji , Fukui Kenji 
Published: July 2006

Abstract
A total synthesis of (±)-taxodione (I) has been achieved. The Friedel and Crafts reaction of 1,2-dimethoxy-3-isopropylbenzene (IV) with succinic anhydride gave β-(4-hydroxy-3-isopropyl-5-methoxybenzoyl)propionic acid (V), which was then converted to γ-(4,5-dimethoxy-3-isopropylphenyl)butyric acid (IX). Since the cyclization of IX gave 6,7-dimethoxy-8-isopropyl-1-tetralone (X), the acid (IX) was subjected to bromination, cyclization, and then debromination. Subsequently, 7,8-dimethoxy-6-isopropyl-1-tetralone (XIII) was converted to (±)-7,8-dimethoxy-6-isopropyl-1-methyl-2-tetralone (XV). The condensation of (±)-XV with the methyl vinyl ketone gave a (±)-hexahydro-2-oxo-phenanthrene derivative (XVI), which was then further converted to (±)-11,12-dimethoxyabieta-5,8,11,13-tetraene (XIX). The introduction of a carbonyl group at the 6 position was achieved by the hydroboration of (±)-XIX, followed by the oxidation of the resulting 6-hydroxyl derivative. Finally, (±)-11,12-dimethoxyabieta-8,11,13-trien-6-one (XXI) was converted to (±)-I, whose IR, UV, and NMR spectra were identical in every respect with those of natural taxodione.
The Hofmann Rearrangement. IV. Kinetic Isotope Effect of N-Chlorobenzamide
Authors: Imamoto Tsuneo , Kim Seung-Geon , Tsuno Yuho , Yukawa Yasuhide 
Published: July 2006

Abstract
Kinetic isotope effects in the Hofmann rearrangement of phenyl-1-14C and carbonyl-14C labeled N-chlorobenzamides were measured in a sodium hydroxide solution at 15°C. The observed isotope effect on the phenyl-1-carbon is
k 12⁄k14=1.0456±0.0012
and that on carbonyl-carbon is
k 12⁄k14=1.0447±0.0006
These results strongly support a concerted mechanism for this rearrangement. Attempts have been made to correlate the isotope effect on phenyl-1-carbon to the r-value of the linear aromatic substituent-reactivity relationship in related 1,2-rearrangements.
Synthetic Studies of Amino Acids by the Use of Copper Complex. II. The Condensation Reaction of N-Pyruvylideneglycinatocopper(II) Complexes with various Aldehydes
Authors: Ichikawa Tetsuya , Maeda Sadao , Okamoto Toshiro , Araki Younosuke , Ishido Yoshiharu 
Published: July 2006

Abstract
An investigation of the mechanism of the reaction which involves the base-catalyzed condensation of bis(glycinato)copper(II) with aldehydes was carried out with the purpose of improving it so that it can proceed even with lower molar equivalent ratios of aldehydes to the complex and under milder conditions. On the basis of the results reported in the literature and those of this investigation, the reaction has been carried out as expected and has been newly shown to be applicable to p-tolualdehyde and p-chlorobenzaldehyde, and, moreover, to such aldehydo sugar derivatives as 2,3-O-isopropylidene-d-glyceraldehyde by the use of N-pyruvylideneglycinatocopper(II) complexes in the reaction in place of bis(glycinato)copper(II). An attempt at further improvement will also be described in the present communication.
Studies of Hydroxy Amino Acids. I. Separation of Diastereoisomers of Threonine
Authors: Ariyoshi Yasuo , Sato Naotake 
Published: July 2006

Abstract
It was found that Dl-allothreonine forms scarcely any soluble compounds with 5-nitronaphthalene-1-sulfonic acid, α-naphthylphosphoric acid, chlorendic acid, and tetrachlorophthalic acid in water. Dl-Threonine formed soluble or unstable compounds in water with these acids. The synthetic threonine mixture was successfully separated into Dl-threonine and Dl-allothreonine.
Chemically Induced Dynamic Nuclear Polarization in the Photochemical Reaction of Phenanthraquinone with Hydrogen Donors. II. A Consideration of Unusual Nuclear Spin Polarization
Authors: Shindo Heisaburo , Maruyama Kazuhiro , Otsuki Tetsuo , Maruyama Tetsuo 
Published: July 2006

Abstract
Polarized quartet NMR signals due to methylene protons were observed in the hydrogen-abstraction reactions of phenanthraquinone with o-substituted toluenes under the irradiation of light. The relative intensities of these signals could be predicted only by the general treatment of the CKO theory, taking account of the electronic singlettriplet interactions (S–T0 and S–T1) of the radical pair. The scalar electronic-coupling constants, Je, were evaluated approximately by comparing the theory with the experimental results and were found to be in the order of 7×109 sec−1. The rather large value of Je was discussed in relation to the nature of the reaction system; consequently, the existance of electronic π–π interaction was suggested for the radical-pair intermediate of the reaction.
Ambident Ion. VI. Kinetical and Thermodynamical Control in the Acylation of β-Dicarbonyl Compounds. Acetylation of Benzoylacetone and Benzoylacetonate Anion
Authors: Suama Masakazu , Nakao Yukimichi , Ichikawa Katsuhiko 
Published: July 2006

Abstract
Kinetically as well as thermodynamically controlled steps have been established in acetylation of ambident ion. Acetylation of sodium benzoylacetonate in pyridine gave initially the kinetically controlled product (I) which isomerized gradually to the thermodynamically controlled (II). C-Acetylation product (III) was formed by the reaction of benzoylacetonate ion with O-acetylbenzoylacetones at higher temperatures. Comparison of the results in the acetylation of benzoylacetone with those of its sodium salt suggested that enolate anion was the reacting species in both processes of O- and C-acetylation. Isomerization between I and II was suppressed in α-picoline or 2,6-lutidine solution. Utilizing these results we have prepared three kinds of acetylated products I, II, and III readily in high selectivity.
Studies of Thioiminocarbonates. I. The Formation and Decomposition of O-Alkyl S-Aryl Thioiminocarbonates in the Reaction of Aryl Thiocyanates with Alcohols in the Presence of the Cyanide Ion
Authors: Tanaka Kazuhiko , Hayami Jun-ichi , Kaji Aritsune 
Published: July 2006

Abstract
The reactions of aryl thiocyanates (I) with alcohol in the presence of cyanide ion were found to give alkyl aryl sulfides (III). The intermediate was isolated in the case of p-tolyl thiocyanate with methanol at 0°C and was determined to be O-methyl S-p-tolyl thioiminocarbonate (IIa) on the basis of NMR and IR spectral studies. The treatment of IIa with the cyanide ion afforded methyl p-tolyl sulfide (IIIa) in a high yield. When a mixture of an equimolecular amount of O-methyl S-p-tolyl thioiminocarbonate (IIa) and O-ethyl S-p-chlorophenyl thioiminocarbonate (IId) was treated with sodium cyanide in ethanol, all the anticipated sulfides—methyl p-tolyl sulfide (IIIa), p-tolyl sulfide (IIIb), methyl p-chlorophenyl sulfide (IIIc) and ethyl p-chlorophenyl sulfide (IIId)-—were isolated. The mechanistic route, which involves the addition of alcohol to aryl thiocyanate, and the dissociation of the resulting O-alkyl S-aryl thioiminocarbonate (II) into aryl mercaptide ion and aryl cyanate, was proposed.
Synthesis and Conformational Studies of [7](2,6)Pyridinophanes
Authors: Fujita Shinsaku , Nozaki Hitosi 
Published: July 2006

Abstract
[7](2,6)Pyridinophane (V) and the 4-deuterio derivative (VD) are prepared from cyclododecane-1,5-diones (IV and IVD). Lithiation at the α-position of V and the subsequent derivation give 1-methoxycarbonyl- (VIII), 1-hydroxy- (IX), 1-oxo- (X), and 1,1-dimethoxy[7](2,6)pyridinophane (XI). A bathochromic shift in UV spectra is observed and ascribed to the nonplanarity of the pyridine ring. The protons on the C4 of these heterophanes experience strong shielding due to the magnetic anisotropy of the respective pyridine rings. The shielding of the C4 protons is more pronounced at low temperatures; this can be explained by assuming an extreme conformation such as XII. The temperature dependence of the NMR spectra is examined, and the energy barriers (ΔGc\eweq) for the conformational changes (XII\ightleftarrowsXII′) are estimated to be 9.0 for V and 9.6 kcal/mol for XI. [7](2,6)Pyrylophanium perchlorate (VI) is prepared, in which a similar shielding effect of the pyrylium ring is observed.
Near Ultraviolet Absorption Spectrum of Pyridine-d5 Vapor
Authors: Hasegawa Yoshinori 
Published: July 2006

Abstract
The near ultraviolet absorption spectrum of pyridine-d5 vapor due to n–π* transition was measured and analyzed. The origin is at 34951 cm−1 and higher than that of pyridine-h5 by 182 cm−1. The ground-state frequencies 582 and 1019 cm−1 and their counterparts of 511 and 953 cm−1 in the upper state dominate the progressions in the spectrum. Besides the above frequencies, several active frequencies were obtained.
Kinetic Studies of the Solvent Extraction of Metal Complexes. I. The Extraction of the Beryllium(II)-TTA Chelate from Aqueous Perchlorate Media into Carbon Tetrachloride and Methyl Isobutyl Ketone
Authors: Sekine Tatsuya , Koike Yasuaki , Komatsu Y\={u} 
Published: July 2006

Abstract
The rate of extraction of beryllium ions from aqueous 4.0m or 0.1m sodium perchlorate-chloride or -nitrate ionic media into carbon tetrachloride or MIBK (methyl isobutyl keton) as a chelate complex with TTA (thenoyltrifluoroacetone) has been determined at 25°C. The rate of extraction in the carbon tetrachloride system is first-order with respect both to the beryllium ion and the dissociated TTA anion in the aqueous phase. The rate constant for this reaction is about 2×104m2min−1. The rates in these systems are not influenced by the replacement of perchlorate ions by nitrate or chloride ions in the ionic media when the ionic concentration is kept constant. On the other hand, it was found that three extraction reactions take place in the MIBK systems. The rate of these extractions is in all cases first-order with respect both to the beryllium ion and the dissociated TTA anion, but is zeroth-, first, or second-order with respect to the perchlorate ions in the aqueous phase. Because of this, the extraction is much faster when the perchlorate concentration is larger; for example, when the concentration of the TTA anion is kept constant, the extraction from a 4.0m sodium perchlorate solution is about 200 times faster than that from the 4.0m sodium chloride solution. From these experimental results, the following conclusions were reached. In the carbon tetrachloride system, the beryllium ion first forms the TTA chelate in the aqueous phase, and then the complex is extracted into the organic phase. The rate-determining step is the 1: 1 complex formation in the aqueous phase. In the MIBK system, on the other hand, the formation of the TTA complex in the aqueous phase, followed by its extraction into the organic phase (zeroth-order reaction with respect to the perchlorate ion), also occurs, but at the same time, the beryllium ion in the aqueous phase is first extracted into the organic phase as ion-pairs, such as BeCl(ClO4) or BeNO3(ClO4) and Be(ClO4)2 (first- and second-order reactions with respect to the perchlorate ions respectively), and the ion-pairs then react with the TTA anions in the organic phase. The enhancement of the rate of extraction by the perchlorate ions in the MIBK system seems to be explained by the overall effect of these extraction mechanisms.
Electron Spin Resonance Study of Short-Lived Free Radicals in Photoreduction of Benzophenone
Authors: Yoshida Hiroshi , Warashina Tetsuo 
Published: July 2006

Abstract
By observing electron spin resonance spectra during photolysis at room temperature, kinetic behaviors of short-lived free radicals are studied in photoreduction of benzophenone in alcohols, especially in ethanol, with and without sodium methoxide. In neutral solution, diphenylhydroxymethyl radicals and hydroxyethyl radicals are observed simultaneously. This is a firm evidence, obtained from ESR, of hydrogen abstraction of excited benzophenone from ethanol. Results indicate that (1) free radicals are the most efficiently generated by the light of ∼350 nm, (2) hydroxyethyl radicals transform into diphenylhydroxymethyl radicals if the concentration of benzophenone is high, and (3) the latter radicals disappear following the second order reaction. In the presence of sodium methoxide, diphenylhydroxymethyl radicals transform into benzophenone ketyl anions.
Rate constants are determined, being 3×107 and ∼104 mole−1·1·sec−1 for the combination reaction between diphenylhydroxymethyl radicals and the proton transfer reaction from diphenylhydroxymethyl radical to methoxide ion, respectively.
Thermoelectric Powers of Molten I2+Te Solutions
Authors: Ichikawa Kazuhiko , Shimoji Mitsuo 
Published: July 2006

Abstract
The initial and steady-state potentials of thermocells of the liquid I2+Te system were measured at temperatures 250–600°C. Cells with a vapor path were used, together with those in which a vapor transport was forbidden. The difference due to these types of cells was found in the values of not the initial thermoelectric powers but the steady-state ones for only solutions with low Te compositions. In the I2-rich region, the mechanism is discussed by using the model of charge-transfer due to I3− as in the case of conductivities and absorption spectra. The thermoelectric data in both the Te-rich and intermediate composition regions suggest that electronic contributions are highly predominant and a transition to delocalized states continuously appears with increasing Te concentration. Some experiments were carried out in order to examine the formation of concentration gradient due to the thermal effect in low Te compositions.
Properties of Water in Macromoleular Gels. III. Dilatometric Studies of the Properties of Water in Macromolecular Gels
Authors: Aizawa Masuo , Suzuki Shuichi 
Published: July 2006

Abstract
The dilatometric properties of W1 W2, and W3, which were proposed by the present authors, for the classification of water in macromolecular gels, are studied over the range from −30 to 60°C. From the results of the thermal expansion of agarose gels and Sephadex (cross-linked dextrans), higher water contents of gel were found to show an extremely sharp volume change at 0°C; on the contrary, lower water contents of gel exhibited no anomalous change in the specific volume in the range from −30 to 0°C, and a gradual decrease in the specific volume was detected with an increase in the temperature in the range from −20 to 0°C for medium water contents of the gel, though the gel was expected to increase in its volume in that temperature range. Thus, the new classification for the states of water in macromolecular gels was shown to be reasonable, at the same time, the transition temperatures of W1 W2, and W3 were evaluated on the basis of the above results.
The thermal expansion of water in macromolecular gels, even of W1 was found to be extremely depressed by the polymers of such gels.
Scmielassical Calculation of the Vibrational Transition Probabilities of Diatomic Molecules in Collision. The Effect of Vibrational Anharmonicity
Authors: Yonezawa Yoshiro , Fueno Takayuki 
Published: July 2006

Abstract
The multi-state semiclassical method proposed by Sharp and Rapp for calculating the vibrational transition probabilities of harmonic oscillators in collision was extended to Morse oscillators. Model calculations have been carried out for the excitation of a vibrational ground-state hydrogen molecule colliding with a helium atom at varying relative velocity. It has been shown that the Morse oscillator model gives greater transition probabilities than the corresponding harmonic oscillator model.
The Crystal and Molecular Structure of Bis(o-ethoxyphenyl)butadiyne
Authors: Taga Tooru , Masaki Norio , Osaki Kenji , Watanabé Tokunosuke 
Published: July 2006

Abstract
The crystal structure of bis(o-ethoxyphenyl)butadiyne has been determined by the statistical method of X-ray analysis. The space group is P21⁄a with two molecules in the unit cell of dimensions a=14.64, b=11.27, c=5.19 Å, and β=105.6°. The crystal structure is built up from columns of the molecules packed along the c-axis. The molecule has a center of symmetry and is almost planar. The diacetylene group is slightly twisted and the three conjugated bond distances of the diacetylene group are 1.434, 1.201, and 1.371 Å.
Effects of External Pressure on the Light Absorption and Fluorescence of s-Tetracyanobenzene Complexes
Authors: Torihashi Yoshikazu , Furutani Yoshifumi , Yagii Kiyoshi , Mataga Noboru , Sawaoka Akira 
Published: July 2006

Abstract
The effects of high pressure on the charge-transfer (CT) absorption and fluorescence spectra of tetracyanobenzene (TCNB) complexes at room temperature have been examined. The pressure-induced change in the absorption intensity indicated the reduction of the distance between donor and acceptor in the complex and the increase in the overlap between their electron clouds. The pressure-induced red shifts of the absorption and fluorescence spectra were almost equal to each other in the case of the TCNB-toluene system, but the former shift was larger than the latter shift in the case of the TCNB-mesitylene system. These results were interpreted in terms of the reduction of the donor-acceptor distance in the complex as well as in terms of electrical solute-solvent interactions. It has been confirmed that the fluorescence quantum yield and the decay time of the complex decrease with the increase in the pressure, and that the rate of the decrease of the former is much larger than that of the latter, in the case of TCNB-toluene system. These results have been interpreted as being due to the pressure-induced increase in the quenching process at the Franck-Condon excited state as well as in the course of the relaxation process from the excited Franck-Condon state to the equilibrium fluorescent state.
Kinetics of Silver(I) Ion Catalysed Oxidation of Glycine by Peroxodisulphate Ion
Authors: Chandra G , Srivastava S N 
Published: July 2006

Abstract
The kinetics of Ag(I) ion catalysed oxidation of glycine by peroxodisulphate in aqueous medium has been studied. The reaction is found to be first order in peroxodisulphate and Ag(I) ions and almost independent of glycine concentration. The rate constant is found to decrease with the increase in the concentration of peroxodisulphate ion. Addition of neutral salts shows a retarding effect. A suitable mechanism has been proposed and a theoretical rate law has been derived to account for the results.