bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on Mass Spectrometry of Metal Chelates. III. Mass Spectrometry of 2-, 4-, 5-, 7-Methyl-, and 5-Chloro-oxine Metal Chelates
Authors: Naga Shinobu , Kidani Yoshinori , Koike Hisashi 
Published: July 2006

Abstract
For application of mass spectrometry to metal chelate chemistry, a group of divalent metal chelates (Co, Ni, Cu, Zn, and Pd) of 2-Me-oxine, 4-Me-oxine, 5-Me-oxine, 7-Me-oxine, and 5-Cl-oxine has been investigated. 2-Methyloxine and 4-Me-oxine of these ligands give similar spectra and are considered to have similar fragmentation patterns. The same was found for 5-Me-oxine and 7-Me-oxine. However, the spectra of 2-Me-oxine and 4-Me-oxine metal chelates differ from each other, as do also the spectra of 5-Me-oxine and 7-Me-oxine. Thus fragmentation patterns may vary with the metal chelate formation of the ligands even when they have the same fragmentation patterns. Each metal chelate gave two peaks corresponding to metal-containing ions, a molecular ion (I) of a 2:1 (ligand: metal) chelate, and a fragment ion (II) of a 1: 1 chelate due to the loss of a hgand radical from ion I. In the case of Co, Ni, Zn, and Pd chelates of 2-Me-oxine, a peak corresponding to the loss of a methyl radical from I was observed, apparently caused by steric effect. In the metal chelates of 5-Me-oxme, a peak corresponding to the loss of a hydrogen radical from I was also observed. However, the fragmentation pathway of formation of II from I is commonly observed in all metal chelates. Since this pathway is comparable with the second successive formation reaction (k2) in solution, the peak intensity ratio of the ion of I to that of II was calculated. From the results it was found that the stability of the chelates decreases in the order Zn&gt;Ni&gt;Pd∼Co&gt;Cu and that it depends on the charge-radius ratio (e⁄r) of the central metal ion, or the stability constant (logk2) observed in solution.
Isomerism of the Metal Complexes Containing Multidentate Ligands. V. Preparation and Properties of Optically Active Tris-(diaminosuccinato)cobaltates(III)
Authors: Kojima Masaaki , Yoshikawa Yuzo , Yamasaki Kazuo 
Published: July 2006

Abstract
Tris(diaminosuccinato)cobaltates(III) with meso, racemic, and laevorotatory ligands were prepared and resolved by column chromatography on DEAE-cellulose and by the use of cinchonidine. The resolved complexes and their absolute configurations, assigned on the basis of the electronic and circular dichroism spectra, and on the basis of the elution order in cellulose column chromatography, are Δ-(−)589-[Co(mdas)3]3−, Λ-(+)589-[Co(mdas)3]3−, Λ(lel)-[Co(ldas)3]3−, and Δ(ob)-[Co(ldas)3]3−
The Crystal Structure of α-Barium 12-Tungstosilicate, α-Ba2SiW12O40·16H2O
Authors: Kobayashi Akiko , Sasaki Yukiyoshi 
Published: July 2006

Abstract
α-Ba2SiW12O40·16H2O is monoclinic, space group C2/c, with a=25.09(5), b=12.10(2), c=18.79(3) Å, β=122.5(3)°; Dm=4.95 g cm−3 and Dx=4.78 g cm−3 for Z=4. The crystal consists of the well known Keggin ion SiW12O404−, having a SiO4 tetrahedron in the center, bound by Ba2+ and water molecules to form a three-dimensional framework. Four water molecules could not be located on electron-density maps, which seem to be disordered or “zeolitic”. The structural relationship of the Keggin ion to its isomer, the β-SiW12O404− polyanion found in β-K4SiW12O40·9H2O, is discussed. Mutual transformation between α- and β-isomers can occur through rotation of a W3O13 group which is a building-unit of both α- and β-polyanions.
Reactions of 1,8-Dehydronaphthalene with Cyclic Polyenes
Authors: Kato Masahiko , Takaoka Shigeru , Miwa Toshio 
Published: July 2006

Abstract
The reactivities of 1,8-dehydronaphthalene (1) to cyclic polyenes, i.e., cycloheptatriene, cyclopentadiene, 6,6-dimethylfulvene, furan, and norbornadiene, were examined. It was found that the C–H insertion reaction at the end of the conjugated systems, a new type of reaction of 1, as well as the 1,2-cycloaddition reaction occurs in every conjugated cyclic polyene. A stepwise mechanism for the formation of the C–H insertion product was proposed.
The Crystal and Molecular Structure of (+)-1,2-Dibromo-2-phenylethyl p-Tolyl Sulfoxide
Authors: Iwasaki Fujiko , Mitamura Shuichi , Tsuchihashi Gen-ichi 
Published: July 2006

Abstract
The crystal structure of (+)-1,2-dibromo-2-phenylethyl p-tolyl sulfoxide, a dominant isomer formed by the ionic bromination of (+)-trans-β-styryl p-tolyl sulfoxide, has been determined by the X-ray diffraction method. The crystal is monoclinic; space group, P21; a=16.193, b=5.706, c=8.541 Å, β=93.51°, and Z=2. The final R value is 0.087 for 792 observed reflections. The absolute configuration has been established to be Ss, SC(1), SC(2) from the CuKα anomalous scattering of the bromine and sulfur atoms. The sulfinyl oxygen is gauche to the bromine atom across the S–C(1) bond, and the non-bonding distance between the both atoms is 3.13 Å. The bromine atom is trans to another bromine across the C(1)–C(2) bond. Based on the assigned structure, a mechanism which involves the preferential formation of an intermediary bromonium ion is elucidated for the bromination. The configuration at the sulfur atom is retained during the reaction.
Dielectric Relaxation and Molecular Structure. XIII. The Dielectric Behavior of Mixtures of 1-Propanol with Hydrogenbonding and Non-hydrogen-bonding Solvents
Authors: Koshii Taro , Takahashi Hiroaki , Higasi Keniti 
Published: July 2006

Abstract
The dielectric constants and losses of 1-propanol and its mixtures with benzene, chlorobenzene, 1,4-dioxane, and pyridine have been measured in the frequency range of 1–0.35 GHz in the temperature range of 10–40 °C. The concentrations of the mixture lie between 1–0.6 mol fractions of the alcohol. The dielectric relaxations of the observed systems in the above frequency range are all of the Debye type. The measured data were used to calculate the activation enthalpy, ΔH*, and the entropy, ΔS*. The dependence of ΔH* and ΔS* upon the concentration differs with the nature of the solvent. Both ΔH* and ΔS* decrease upon the addition of a hydrogenbonding solvent, while they increase slightly upon the addition of a non-hydrogen-bonding solvent. The mechanism of the principal relaxation of 1-propanol is discussed on the basis of these observations.
The Hydrogen-Deuterium Exchange of 3,5-Dimethylisoxazoles
Authors: Kashima Choji , Yamamoto Yasuhiro , Tsuda Yoshihiko , Omote Yoshimori 
Published: July 2006

Abstract
By the hydrogen-deuterium exchange reaction in methano d4, 3,5-dimethylisoxazole (1) was found to react regioselectively at the C-5 methyl group. This methyl group was, however, less reactive than the methyl groups of 2-picoline or quinaldine. This reaction was shown to be retarded by the electron-donating substituents, and to be accelerated by the electron-withdrawing substituents, at the C-4 position of 1.
The Photochemical Cycloaddition of the Enol Acetate of Dimedone to Cyclopentene
Authors: Umehara Misao , Oda Tomio , Ikebe Yoshinori , Hishida Shinzaburo 
Published: July 2006

Abstract
The photochemical cycloaddition of the enol acetate of dimedone to cyclopentene yields two stereoisomers I and II of 2-acetoxy-4,4-dimethyltricyclo[6.3.0.02,7]undecan-6-one. The NMR and IR data suggest a cis-anti-cis configuration for I and a cis-anti-trans configuration for II. The NMR and IR spectra determined on III, IV and V, the NaBH4 reduction products of I and II, also support these configurations. Both of the photo adducts, I and II, lose acetic acid in the presence of an alkali to give an α,β-unsaturated ketone (VI), while it undergoes retro-aldol cleavage in the presence of an acid to give 4,4-dimethylbicyclo[6.3.0]undecane-2,6-dione (VII). A comparative study was made of the mass spectra of I, II, and VI.
Synthetic Studies on Phosphorylating Reagent. V. A Convenient Synthesis of 2′,3′-Cyclic Coenzyme A
Authors: Taguchi Yoshihiko , Nishimura Noriyuki , Kakimoto Toshio , Mushika Yoshitaka 
Published: July 2006

Abstract
A convenient method has been developed for the preparation of 2′,3′-cyclic Coenzyme A (5). It was readily prepared in a good yield from the reaction of adenosine-5′ 2-dimethylamino-4-nitrophenyl phosphate (3) with d-pantethine-4′,4″-diphosphate (4) in the presence of acetic acid in pyridine. Compound 3 and the diphosphate 4 were prepared in a good yield from the condensation of adenosine (1) with 2-dimethylamino-4-nitrophenyl phosphate (2) in the presence of dicyclohexylcarbodiimide (DCC) and the phosphorylation of d-pantethine with 2, respectively.
Phosphate 5 was hydrolyzed with 0.1 M-hydrochloric acid and subsequently reduced with 2-mercaptoethanol to confirm its structure of 5. One of the products, Coenzyme A (reduced form) (6) showed 102% activity with phosphotransacetylase.
Chemistry of 1,3-Glycol Derivatives. I. The Reactions of 2,4-Pentanediol Derivatives
Authors: Itoh Osamu , Ichikawa Yasunori , Katano Hiroaki , Ichikawa Katsuhiko 
Published: July 2006

Abstract
Cyclic orthoacetates of meso- and dl-2,4-pentanediol (cis- and trans-2-ethoxy-2,4,6-trimethyl-1,3-dioxane, 1) were prepared and characterized by NMR. The stereochemical courses of the reactions of 1 with water, hydrogen chloride, trityl chloride, and acetic acid were investigated. The reactions with water gave 4-acetoxy-2-pentanol (4) with complete retention of configuration, while those with the other reagents gave 4-acetoxy-2-chloropentane (3) and 2,4-diacetoxypentane with complete inversion. Acetolyses of 3 and the tosylate of 4 gave 2,4-diacetoxypentane predominantly with retention in the absence of water. Hydrolysis of the tosylate gave 4 with almost complete inversion. These results can be explained by the mechanism that the reactions proceed mainly through acetoxonium cation intermediate involving six-membered ring. The fluoroborate salt of this acetoxonium cation was prepared and characterized by NMR.
Chelation Effect of Alizarin Dyes on the Semiconductor–Aqueous Solution Systems
Authors: Matsumura Michio , Nomura Yoichi , Tsubomura Hiroshi 
Published: July 2006

Abstract
The dye-sensitized photocurrents produced by some semiconductor (titanium dioxide single crystal or zinc oxide sinter) in electrolyte solutions containing alizarin dyes were studied. The photocurrent was concluded to be caused by the sensitization of the alizarin dyes chelated to the semiconductor electrodes.
Synthesis, Thermolysis and Photolysis of Trimethylammonium-N-diphenylphosphinylimine
Authors: Kameyama Eiichi , Inokuma Seiichi , Kuwamura Tsunehiko 
Published: July 2006

Abstract
Ammonim-N-phosphinylimine was prepared from the corresponding hydrazinium salt. The ylid gave phosphinylnitrenes on thermolysis, predominantly in the singlet state. On photolysis, the ylid also gave a singlet product.
A Proton Magnetic Resonance Study of the Amide Configurations of 2-Acylaminopyrimidines
Authors: Kondo Michio 
Published: July 2006

Abstract
It has been found, from the 1H NMR spectra at various temperatures, that 2-formylaminopyrimidine (2) exists in a cis configuration in chloroform and dimethyl sulfoxide, whereas 2-acetylaminopyrimidine (3) exists in a rapid rotational equilibrium between cis and trans configurations in CDCl3, but almost exclusively in a trans configuration in DMSO at room temperature.
Studies of the Effect of Ethanol and Sodium Chloride on the Micellization of Sodium Dodecyl Sulfate by Gel Filtration
Authors: Suzuki Hitoshi 
Published: July 2006

Abstract
The effects of the addition of ethanol and sodium chloride to aqueous solutions of sodium dodecyl sulfate (SDS) were studied by the gel-filtration method. With an increase in the concentration of ethanol, the CMC decreased and then increased after passing a minimum, while the micellar weight increased and then decreased, showing a corresponding maximum. Above about 40 vol% ethanol, no micelle formation was observed. The micellar weight and aggregation number in the presence of ethanol were measured in the SDS concentration range of a constant elution rate of micelles. A decrease in the CMC and an increase in the micellar weight of SDS were observed with an increase in the concentration of NaCl from 0 to 10 mmol/1. The gel-filtration study enabled us to make a direct experimental confirmation of the effects of ethanol and NaCl on the micelle formation of SDS.
A Proton Magnetic Resonance Study of the Molecular Configurations of 2′,5′-Dichloroacetoacetanilide in Various Solvents
Authors: Kondo Michio 
Published: July 2006

Abstract
It has been found by 1H NMR spectroscopy that 2′,5′-dichloroactoacetanilide (1) exists predominantly in the keto form containing an intramolecular hydrogen bond between the amide proton and the carbonyl oxygen at the γ-position in chloroform solutions. In pyridine, the line broadening of signals suggests a rapid interconversion between the keto and enol forms. Configurations of the enol form are discussed.
A Study on the Anode Effect in KF-2HF System. II. Difference in Anodic Behavior between Edge Plane and Layer-plane of Pyrolytic Graphite
Authors: Imoto Hiroki , Watanabe Nobuatsu 
Published: July 2006

Abstract
The anodic behavior of pyrolytic graphite has been studied by voltammetry and ESCA analysis in the molten KF-2HF system at 100°C, attention being given to the difference in anodic behavior between the edge plane and layer-plane of the pyrolytic graphite. The polarization current obtained by a linear potential sweep experiment decreased rapidly with increasing potential after the onset of the anode effect. When the edge plane was used as a working electrode surface the current density was recovered on the subsequent sweep toward negative potentials, whereas the current density was hardly recovered on the layer-plane surface of the electrode. The difference in polarization behavior was interpreted on the basis of the difference in the rate of decomposition reaction of graphite fluoride, (CF)n, formed on the electrode surface. ESCA spectra of the electrodes polarized at various potentials indicate that (CF)n was formed even at 2.0 V vs. Pt, below the fluorine evolution potential, on the edge plane of the pyrolytic graphite and that its amount did not increase appreciably with increasing potential. On the layer-plane, however, no formation of (CF)n was observed at 2 V vs. Pt, its amount increasing appreciably with potential at the potentials above 3 V vs. Pt.
Excited-State Dipole Moments of Azulene and 3,5-Dimethylcyclopent[ef]heptalene
Authors: Yamaguchi Hiroyuki , Ikeda Teruki , Mametsuka Hiroaki 
Published: July 2006

Abstract
The dipole moments of the lower two singlet excited states of azulene (I) and 3,5-dimethyl derivative of cyclopenta[ef]heptalene (II) have been determined from the frequency shift of the absorption and emission spectra in various solvents. The direction of the excited-state dipole moments of molecules I and II is opposite to the direction of the ground-state dipole moments. The dipole moments of the two excited states of molecules I and II have been calculated by using the semi-empirical SCF-π-MO CI method. There is a general agreement between the theoretical results and the experimental results. This agreement shows that the polarization effect of the σ-electrons is almost identical in the ground and excited states of both molecules.
Chemisorption of Nitrogen Oxide and Nitrogen on Tungsten
Authors: Tamura Teijiro , Hamamura Takuya 
Published: July 2006

Abstract
The chemisorption of nitrogen oxide and nitrogen on a polycrystalline tungsten filament was studied using flash desorption mass spectroscopy. The saturation coverage for nitrogen oxide and nitrogen on tungsten is 8.8×1014 molecules/cm2 and 1.9×1014 molecules/cm2, respectively. These saturation coverages on tungsten are about 1.7 times those on rhenium. The initial sticking probability of nitrogen oxide is very high compared with other gases. It is assumed that the nitrogen oxide adsorption is non-dissociative on tungsten, while the nitrogen is adsorbed dissociatively. When the temperature of the tungsten filament saturated with nitrogen oxide is raised, a small amount of nitrogen oxide molecules desorb at about 475 K, and dissociation occurs at more elevated temperatures. The greater part of the nitrogen desorbs before the temperature reaches 1500 K. No oxygen desorption was detected upon heating the tungsten saturated with nitrogen oxide. It appears that oxygen probably desorbs as tungsten oxide. Three states of nitrogen desorption, designated α, β1, and β2, on tungsten appeared at room temperature. The activation energy of the desorption for the strongly chemisorbed nitrogen of the β1 and β2 states on tungsten are 78 kcal/mol and 80.5 kcal/mol, respectively.
Proton Magnetic Resonance Spectra of Metal Ammine Complexes. VIII. Hydrogen Isotopic Exchange in the [Co(O)2(N)4]+ Complex Ions
Authors: Taura Toshiaki , Sakaguchi Ushio , Yoneda Hayami 
Published: July 2006

Abstract
The rates of amine hydrogen isotopic exchange in the [Co(O)2(N)4]+ complex ions, where (O)2 represents carbonate, oxalate, or malonate ions, and (N)4, tetraammine, bis(ethylenediamine), or bis(trimethylenediamine), were measured in D2O at 35 °C by the PMR technique. It was found that: (1) the rates for trans (to oxygen) amines are faster than those for cis amines; (2) the rates, especially for trans amines, in the carbonato complexes are slower than those in the oxalato and malonato analogs, and (3) the difference between the rates for cis and trans amines is smaller in the bis(diamine) complexes than in the tetraammine complexes. These results are discussed in terms of the influence of the chelate geometry in the complex on the exchange reaction.
Application of the Zone Melting Technique to Metal Chelate Systems. XII. Computer-assisted Consideration on the Intermittent Zone Melting
Authors: Yoshida Isao , Kobayashi Hiroshi , Ueno Keihei 
Published: July 2006

Abstract
The solute distribution profile on a columned charge of length L after m-cycles of the intermittent zone melting with j zones of length l, was computed for a range of distribution coefficient, k. The effects of j, l and k upon the separation efficiencies by this method were investigated in terms of the fractional length, α, which was refined to an required purity level, γ, in a limited number of m, and the fractional ratio, σ, of a solute amount which was concentrated into a limited portion of a fractional column length, β. The intermittent method is superior in respect to the separation efficiencies, α as well as σ, over the usual method, if a columned charge was zone-melted with the same number of zones of the same length at the same zone-travelling speed. Results of theoretical calculation were confirmed on systems of azobenzene in naphthalene and those of some metal acetylacetonates in the beryllium chelate of the same ligand compound.
Reaction of Isocyanides with Mercuric Chloride
Authors: Sawai Hiroaki , Takizawa Takeo 
Published: July 2006

Abstract
Isocyanides reacted with mercury(II) chloride in dry tetrahydrofuran upon heating to afford low molecular weight polymers and oligomers. Isocyanides without bulky groups underwent polymerization catalyzed by mercury(II) chloride. Various heterocyclic oligomers were obtained from the reaction of 2,6-xylyl isocyanide with mercury(II) chloride.
Study of Metal–Polycarboxylate Complexes Employing Ion–Selective Electrodes. Cu(II) and Cd(II) Complexes with Poly(acrylic acid) and Poly(itaconic acid)
Authors: Yamashita Fumitaka , Komatsu Tsuyoshi , Nakagawa Tsurutaro 
Published: July 2006

Abstract
The complex formation of bivalent metal ions, Cu(II) and Cd(II), with poly(acrylic acid) and poly(itaconic acid) in aqueous solutions was studied by pH titration at 25 °C and at an ionic strength of 0.1, and at the same time the concentration of free metal ions was measured using ion-selective electrodes. In order to calculate the equilibrium constants of metal–polycarboxylate complex formation, a modified Gregor method is proposed and a more reasonable method for the determination of the formation constants of the complexes is also presented. The equilibrium constant of the metal–polycarboxylate complex formation involving two carboxylate groups was calculated from this method. The value for the Cu(II)–poly(itaconic acid) complex formation was 10−2.9, and was constant in the lower neutralization region. But constant values for the Cd(II) complexes were not obtained over the entire neutralization range.
Thermal Change of Magnesium Highpolyphosphate Coacervates
Authors: Umegaki Takao , Nakayama Yukihiro , Kanazawa Takafumi 
Published: July 2006

Abstract
The thermal change of magnesium highpolyphosphate coacervates with various sodium contents was studied by means of DTA, TGA and high temperature X-ray diffraction technique. Most of the highpolyphosphates in the coacervates were degraded into hydrated orthophosphates up to about 100 °C, the pyrophosphates and tetrametaphosphates being formed at 200–300 °C and 300–500 °C, respectively. The formation temperature of “X” (a mixture of Mg2P2O7 and MgNa2P4O12) was lowered with an increase of sodium content in the coacervate samples. Mg(H2PO4)2·2H2O, Mg(H2PO4)2, MgH2P2O7, “X” and Mg2P4O12 were determined in the crystalline substances obtained by the isothermal heat treatment of coacervates at various temperatures.
Ternary Complexs: Equilibrium Studies of Mixed-ligand Complexes of Neodymium Ion with Carboxylic and Phenolic Acids in Aqueous Medium
Authors: Shelke D N , Jahagirdar D V 
Published: July 2006

Abstract
The stability constants of simple and mixed ligand systems of neodymium ion with bidentate ligands such as carboxylic and phenolic acids are studied in an aqueous medium by pH metric titrations at 30±0.1 °C and at an ionic strength of 0.1 M (NaClO4). Neodymium forms 1 : 1 complexes with succinic, adipic, itaconic, malonic, and 3,5-dinitrosalicylic acids and 1 : 1 and 1 : 2 complexes with phthalic, 5-sulfo-, and 4-hydroxysalicylic acids. Ternary complexes of neodymium with these acids when (i) both the ligands are carboxylic acids, (ii) one is carboxylic and the other a phenolic acid, (iii) both ligands are phenolic acids, are studied by potentiometry. The stability constants of these complexes are compared with those of binary complexes. The results have been discussed on the basis of the magnitudes of ΔlogK, KDXY, and logβXY−1⁄2[logβxx+logβyy], and also from the comparison of K2YX and KMX1 or K2XY and KMY1. The values of K2YX are directly related to the acid dissociation constant of the secondary ligand. The overall stability (βXY) is found to be depending on the binary stabilities and the basicities of the ligands.
Reflection Spectra of Acenaphthene Crystals
Authors: Tanaka Masashi 
Published: July 2006

Abstract
The reflection spectra have been measured for acenaphthene crystals. The excited states of the acenaphthene molecule are similar to those of the naphthalene molecule; the lower π→π* excited states are observed at 31100 (α), 32600 (p), 43700 (β), and 47400 (β′) cm−1. In the reflection spectra of the crystal, the α and β states polarized along the b axis are observed at 30900 and 41800 cm−1, respectively. The p and β′ states are found at 32100 and 44000 cm−1 in the a axis spectrum and at 31400 and 45000 cm−1 in the c axis spectrum.
Adduct-Formation Constants of Bis(3-trifluoroacetyl-d-camphorato)copper(II) with Lewis Bases
Authors: Shigematsu Tsunenobu , Matsui Masakazu , Sasaki Yoshihiro , Sakurada Matsujiro 
Published: July 2006

Abstract
The formation constants of the mono-adducts of bis(3-trifluoroacetyl-d-camphorato)copper(II) with the Lewis bases, such as pyridine, α-picoline, β-picoline, γ-picoline, isopropylamine, and d- and l-α-methylbenzylamine, were determined spectrophotometrically.