bluuebunny/crossref_metadata_2025 huggingface dataset:
Excited-State Dipole Moments of Azulene and 3,5-Dimethylcyclopent[ef]heptalene
Authors: Yamaguchi Hiroyuki , Ikeda Teruki , Mametsuka Hiroaki
Published: July 2006

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

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

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

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

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

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

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

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

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

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.
Electronic Spectra and Electronic Structure of TCNQ Complexes
Authors: Tanaka Jiro , Tanaka Masashi , Kawai Takashi , Takabe Teruhiro , Maki Osamu
Published: July 2006

Electronic spectra of several TCNQ, complexes have been measured with single crystals by the transmission method. The assignment of electronic transitions are presented based on the electronic structure of the crystals. The molecular viewpoint is stressed in a theoretical treatment. The spectra are interpreted in terms of the charge transfer between TCNQ species and the local transitions of TCNQ and the donor molecules. It is shown that the electronic structure of the crystal may be deduced from the spectral analysis. The magnetic and electric properties of several conducting TCNQ complexes are discussed by this model with the wavefunctions determined by a theoretical calculation and the analysis of the spectral results.
Flotation of MnO4− and Fe3+ Ions by the Combined Use of Sodium Silicate and Cationic Surfactant
Authors: Takayanagi Isao , Kobayashi Koichi , Hachisuka Keiko , Sasaki Tsunetaka
Published: July 2006

The removals of MnO4− and Fe3+ ions from an aqueous solution by the combined use of silicate ions(SiO32−) and a cationic surfactant, hexadecyltrimethylammonium chloride (HTAC), were studied by means of ion flotation techniques. The effect of variables such as pH, the surfactant concentration, and the order of addition of the reagents on the floatability of the ions were studied. More than 98 and 97% of the MnO4− and Fe3+ ions, respectively, could be floated under the optimum conditions. The optimum composition of SiO32− and HTAC was found to be about 0.9 in mole fraction of SiO32− for both systems. It was also found that the order of the addition of the reagents markedly affects the floatability. Further, a schematic model of flotation was proposed, taking account of the compositions of the sublate. MnO4− and Fe3+ ion flotations differed from each other in that MnO4− ions combine with SiO32− ions through the double layer of HTAC molecules, which are subsequently coagulated and floated by HTAC, while Fe3+ ions or polynuclear Fe3+ ions combine directly with SiO32− ions, which are subsequently coagulated and floated by HTAC.
Aminosugars. XXVI. Synthesis of Amido-bonded Disaccharides Containing Hexosaminuronic Acids
Authors: Yoshimura Juji , Ando Hiroaki , Sato Tadahide , Tsuchida Shigeru , Hashimoto Hironobu
Published: July 2006

Synthesis and properties of amido-bonded disaccharides containing hexosaminuronic acids are described. The amino group of d-gluco- and d-mannosamine derivatives was acylated with d-gluco- and d-mannosaminuronic acid derivatives by the dicyclohexylcarbodiimide method, and the protecting groups of a few products were removed. Some of them showed the additive patterns of components in their PMR spectra.
Synthesis of 3,4-Di-O-acetyl-6-azido-2,6-dideaxy-2-(2′,4′-dinitroanilino)-α-d-glucopyranosyl Chloride
Authors: Ogawa Seiichiro , Fujimori Hitoshi , Suami Tetsuo
Published: July 2006

The title compound has been prepared as an intermediate for the chemical synthesis of glycosides of 2,6-diamino sugar.
Syntheses of Some Alkoxy-, Dialkoxy-, and Alkoxyamino-sulfonium Ions and Their O-Methylene and N-Methylene PMR Chemical Shifts
Authors: Minato Hiroshi , Yamaguchi Kei , Okuma Kentaro , Kobayashi Michio
Published: July 2006

Alkylation of sulfenates proved to be a good method for synthesis of alkoxysulfonium ion not obtainable by alkylation of sulfoxides. Dialkoxy- and alkoxyamino-sulfonium ions were prepared by alkylation of sulfinates and sulfinamides. Ethoxy- and methoxymorpholinophenylsulfonium tetraphenylborates were obtained as high-melting crystals, which almost quantitatively alkylated amines at room temperature. PMR spectra of RR′\overset⊕S–OCHAHBR″ and RR′\overset⊕S–N(R″)CHAHBR'″ were determined, and the relationship between δA–δB and (R,R′) were examined.
Solvent Extraction Equilibria of Acids. IV. Tetrachloroferric Acid in a Hexane Containing Trioctylphosphine Oxide-Aqueous Chloride Solution System
Authors: Sekine Tatsuya , Zeniya Yoshiyuki , Niitsu Masaru
Published: July 2006

From the distribution ratio of iron(III) between hexane containing trioctylphosphine oxide (TOPO) and a 4 mol dm−3 aqueous (H, Na)Cl solution, the extraction constants for the two complexes, Kex8=[FeCl3(TOPO)2]org–[Fe3+]−1[Cl−]−3[TOPO]org−2 and Kex4=[HFeCl4(TOPO)2]org–[Fe−3]−1[Cl−]−4[TOPO]org−2, were determined to be 104.5 and 104.3, respectively. The extractability of tetrachloroferric acid are discussed by comparing the Kex value with that for perchloric acid.
Reduction of α,β-Unsaturated Nitrile to Saturated Nitrile with Sodium Borohydride
Authors: Toda Fumio , Kanno Mutsushi
Published: July 2006

α,β-Unsaturated nitrile (1) was easily reduced to saturated nitrile (2) with sodium borohydride. Phenyl- (7a) and 2-phenanthryl-cyanoacetylene (7b) were also reduced with sodium borohydride to the saturated nitriles, 8a and 8b, respectively.
Photochemical Reduction of 2,3-Dihydro-2,3-methano-1,4-naphthoquinones with Xanthene
Authors: Maruyama Kazuhiro , Tanioka Soji
Published: July 2006

Photochemical reduction of 2,3-dihydro-2-methyl-2,3-methano-1,4-naphthoquinone (1a) and 2,3-dihydro-2,3-dimethyl-2,3-methano-1,4-naphthoquinone (1b) with xanthene was investigated. 6,7,8,9-Tetrahydrobenzocycloheptene-5,9-dione derivatives and stereochemical isomers of the so-called “1,2-adducts” of xanthene to carbonyl groups were isolated as the reaction products. CIDNP technique was applied for the examination of the course of the reactions.
Studies on Heterocyclics. V. Synthesis of Thiazolotriazepines
Authors: Mahajan M P , Sondhi S M , Ralhan N K
Published: July 2006

The possible psychosedative, bridgehead thiazolo[2,3-c]-1,2,4-triazepines have been synthesized by the condensation of 2-hydrazinothiazoles with β-chloropropionyl chloride.
The Crystal and Molecular Structure of an Anti-inflammatory Agent, 1-(Cyclopropylmethyl)-4-phenyl-6-methoxy-2(1H)-quinazolinone(SL-573)
Authors: Kimura Michio , Hirohashi Toshiyuki , Yamamoto Hisao
Published: July 2006

The crystal structure of the title compound (SL-573), crystallized from an ethyl acetate solution, has been determined by the single-crystal X-ray diffraction method. The crystals are monoclinic, with the space group P21/a, and these cell constants: a=17.395(11), b=8.371(5), c=10.871(7) Å, β=99°56(4)′, and Z=4. The intensities were measured visually from equi-inclination integrated Weissenberg photographs taken with Cu Kα radiation. The structure was solved by the symbolic addition method. The final R factor was 0.119 for 3284 reflections. The molecules are placed in pairs around the centers of symmetry and are linked by van der Waals’ distances less than 3.94 Å. The dihedral angle between the quinazoline and phenyl ring planes was found to be 42.8°.
Analysis of the Effect of Added Electrolyte on the Micellar Catalysis
Authors: Shirahama Keishiro
Published: July 2006

The effect of added electrolyte on micelle-catalyzed reaction was analyzed. The log [L.S] vs. log (total counter ion concentration) plot gives a straight line, where [L.S] is a limiting slope on a rate-surfactant concentration plot at an infinitely dilute micellar concentration. The slope is related to the number and the magnitude of the Coulombic term that may be included in the concentration effect of reactants, and in the intrinsic micellar effect, or the relative stabilization of a transition state in the presence of micelles. The above treatment was applied to (1) the hydrolysis of trimethyl orthobenzoate in sodium dodecyl sulfate solution, (2) the fading reaction of Crystal Violet in hexadecyltrimethylammonium bromide (CTABr) solution, and (3) the nucleophilic substitution reaction of 2,4-dinitrofluorobenzene in CTABr solution. It was found that the concentration effect is predominant in (1), while the relative stabilization of the transition state occurs in (2) and (3) in addition to the concentration effect.
Studies on 8,9,10,11-Tetrahydro-7H-cycloocta[de]naphthalenes. I. Conformations of 8,8,10,10-Tetrasubstituted Derivatives of 8,9,10,11-Tetrahydro-7H-cycloocta[de]naphthalene
Authors: Kamada Toshihiro , Wasada Nobuhide , Yamamoto Osamu
Published: July 2006

Several 8,8,10,10-tetrasubstituted 8,9,10,11-tetrahydro-7H-cycloocta[de]naphthalenes (3–9), novel pericyclic compounds of naphthalene, have been prepared through the alkylation reaction of 1,8-bis(bromomethyl)naphthalene and tetraethyl propane-1,1,3,3-tetracarboxylate, and the conformations of the cyclooctene ring in these compounds have been investigated on the basis of the PMR spectra. It is concluded that, at room temperature, the cyclooctene rings of (3–9) are frozen on the NMR time scale and exist exclusively in the boat form 15, which is shown to be the most energetically stable conformation for the peri-eight-ring systems from models. Some discussion is also given on the configurations of the substituent groups in (3–9).
A Mössbauer Study of Graphite Intercalated with Iron(III) Chloride and Aluminum Chloride
Authors: Tominaga Takeshi , Sakai Takuhiko , Kimura Tomohiko
Published: July 2006

The Mössbauer spectra of graphite–FeCl3 and graphite–FeCl3–AlCl3 compounds with varying FeCl3/AlCl3ratios were measured. At 298 K, the isomer shift of the Fe3+ peak of FeCl3 intercalated in the graphite–FeCl3 compounds was larger than that of pure anhydrous FeCl3, and two sets of Fe2+ quadrupole doublets appeared in the spectra of the graphite–FeCl3–AlCl3 compounds with FeCl3/AlCl3 ratios of approximately one or less. These results may be accounted for in terms of the transfer of graphite π-electrons to intercalated FeCl3.
Preparation of Some Alkylthallium(III) Dichlorides and Their Reactions with Potassium and Copper Halides
Authors: Uemura Sakae , Toshimitsu Akio , Okano Masaya
Published: July 2006

A simple synthesis is given for the stable monoalkylthallium(III) dichloride, C6H5CH(OR)CH2TlCl2 (1) from the corresponding diacetate (2) and potassium chloride in methanol or acetonitrile. 1(R=Me) reacts slowly with potassium and copper (I) halides to give mainly α-methoxystyrene and C6H5CH(OMe)CH2X (X=Cl, Br, I), respectively. It is concluded that 1(R=Me) is less susceptible than 2(R=Me) to SN1, SN2, and SNi reactions.
Kinetics of Oxidation of α-Hydroxy Acids by Ceric Sulfate
Authors: Tewari K C , Singh H N , Singh V S
Published: July 2006

The mechanism of the oxidation of α-hydroxy acids by ceric sulfate in sulfuric acid medium has been reexamined in the temperature range 15–30 °C and the thermodynamic parameters have been calculated. The role of HSO4− ion as an active inhibitor has been discussed quantitatively.
Dehydroannulenes. II. Syntheses of Diatropic Dimethyldiphenyl-and Tetraphenyl-tetrakisdehydro[18]annulenes
Authors: Katakami Tsutomu , Fukui Kunisuke , Okamoto Tetsuhiko , Nakagawa Masazumi
Published: July 2006

Syntheses of dimethyldiphenyl-(VI and XII) and tetraphenyltetrakisdehydro[18]annulenes (XVII) have been performed. It was found that the reaction sequence used for the synthesis of tetramethyltetrakisdehydro[18]annulene can be used generally for the preparation of tetrakisdehydro[18]annulenes having various substituents. The annulenes (VI, XII, and XVII) were found to be strongly diatropic having high conformational stability. Remarkable stability is provided by introduction of phenyl groups accompanied with decrease in solubility of the annulene. Dimethyldiphenyl derivative was prepared by two different routes which will lead to isomers (VI and XII) with respect to the relative positions of the diacetylene and hexapentaene linkages to the substituent groups. The isomers (VI and XII) can be regarded as presumably identical, but precise agreement of NMR and UV spectra could not be attained. Bathochromic shift of UV spectra of phenyl substituted annulenes compared with tetramethyl analogue indicated that phenyl groups exert prominent perturbation on the annulene system.
A Potentiometric Study on Complex Formation of Cadmium(H) and Lead(II) Ions with N-(2-Hydroxyethyl)ethylenediamine-N,N′,N′-triacetic Acid
Authors: Oyama Noboru , Shirato Takehide , Matsuda Hiroaki , Ohtaki Hitoshi
Published: July 2006

The complex formation of cadmium (II) and lead(II) ions with AT-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetic acid (HEDTA) has been studied potentiometrically in a 1.0 M NaClO4 medium at 25.0 °C by using glass and metal–amalgam electrodes. The emf data obtained over the pH range 1 to 10 were explained in terms of the formation of the following species: for the Cd–HEDTA system, CdL− (logβ101=13.21±0.04), CdhL (logβ111=15.61±0.02) and CdH2L+ (logβ121=16.68±0.04); for the Pb–HEDTA system, PbL− (logβ101=14.83±0.02), PbHL (logβ111=16.97±0.02),PbH2L+ (logβ121=17.89±0.02) and PbH3L2+ (logβ131=18.67±0.02), where βpqr=[MpHqLr(2p+q−3r)+/[M2+]p[H+]q[L3−]r and L denotes the unprotonated molecule of HEDTA. Protonation constants of HEDTA were determined as logβ011=9.20±0.01, logβ021=14.72±0.01, logβ031=17.06±0.01, logβ041=18.52±0.01 and logβ051=18.65±0.05.
Substrate Specificity in the Cyclodextrin-catalyzed Cleavage of Organic Phosphates and Monothiophosphates in Alkaline Solutions
Authors: Mochida Kazuo , Matsui Yoshihisa , Ota Yoshio , Arakawa Koji , Date Yoshio
Published: July 2006

Cyclodextrin accelerates the phenol release from organic phosphates such as dialkyl 4-nitrophenyl phosphates, but it decelerates the reactions of the corresponding monothiophosphates in alkaline solutions. Each reaction proceeds via the prior formation of a cyclodextrin–substrate inclusion complex, followed by the nucleophilic attack of the cyclodextrin alkoxide ion or the hydroxide ion on the reaction site of the included substrate. The equilibrium and kinetic parameters involved in the reaction processes were determined and discussed in connection with the geometry of a cyclodextrin–substrate complex.
N-Halogen Compounds of Cyanamide Derivatives. VI. The Preparation and Reaction of 2-Carbonimidoyl-3-imino-Δ4-1,2,4-thiadiazolines
Authors: Fuchigami Toshio , Odo Keijiro
Published: July 2006

The reactions of potassium methyl cyanoiminodithiocarbonate (I), potassium methoxy and ethoxythiocarbonylcyanamide (IIa and IIb) with N-chloroamidines in various solvents were investigated. Δ4,2,4-Thiadiazolines (TDZ), IIIa–d, were obtained from I in good yields, whereas the 1,3,5-triazines obtained as by-products in addition to TDZ were formed from II and N-chlorobenzamidine (NCB) in chloroform and dichloromethane. In the latter reaction, desulfrization occurred completely to give 1,3,5-triazine and/or a chain intermediate to 1,3,5-triazine in dipolar solvents. The TDZ were readily cleft at the N–S link by hydrogen sulfide and recyclized to 1,3,5-triazines. By alkaline hydrolysis, the TDZ were transformed to 2-amino-1,3,5-triazin-4-ols.
Arjungenin, Arjunglucoside I, and Arjunglucoside II. A New Triterpene and New Triterpene Glucosides from Terminalia arjuna
Authors: Honda Tadashi , Murae Tatsushi , Tsuyuki Takahiko , Takahashi Takeyoshi , Sawai Masanobu
Published: July 2006

Arjungenin, a new triterpene isolated from Terminalia arjuna, is shown to be 2α,3β,19α,23-tetrahydroxyolean-12-en-28-oic acid (1). The structures of two new triterpene glucosides, arjunglucoside I and arjunglucoside II, isolated from the same plant, were determined to be β-d-glucopyranosyl 2α,3β,19α,23-tetrahydroxyolean-12-en-28-oate (2) and β-d-glucopyranosyl arjunolate (3), respectively.
An Anion Radical Precursor in the Nucleophilic Substitution of o-Dinitrobenzene
Authors: Abe Takehiro , Ikegami Yusaku
Published: July 2006

By visible and ESR spectroscopies, the appearance of o-dinitrobenzene anion radical has been demonstrated for the replacement of one nitro group of o-dinitrobenzene by hydroxide ion in aqueous dimethyl sulfoxide. Kinetic studies have supported the suggestion that the anion radical is a precursor in the substitution reaction.
A General Synthetic Method for 1-Substituted 1,4-Dihydro-3(2H)-isoquinolinones
Authors: Kotake Hiroshi , Kinoshita Hideki , Inomata Katsuhiko , Masuda Hiroshi
Published: July 2006

The reaction conditions for the conversion of 3 into 4 were investigated in some detail, and it was found that the reductive animation of o-acylphenylacetic acid was allowed to proceed smoothly by the use of deactivated Raney nickel.
Microwave Spectrum, Structure, Dipole Moment and Internal Rotation of Ethanethiol. II. Gauche Isomer
Authors: Nakagawa Jun , Kuwada Kazunori , Hayashi Michiro
Published: July 2006

The microwave spectra of gauche-ethanethiol and its isotopic species were studied. Most of the observed spectra for the species having the plane of symmetry exhibited doublet structures with large spacings due to the internal rotation of the mercapto group. The rs structure of the gauche isomer was determined from the observed moments of inertia. The gauche isomer whose dihedral angle τ(CCSH) is 61°45′±58′ has structural parameters close to those for the trans isomer except the angles around the carbon atom in the methylene group. The difference in angle values around the carbon atom in the methylene group between the trans and gauche isomers can be explained by the 3°7′ tilt of the methylene group towards the lone pair electrons on the sulfur atom. The direction of the dipole moment in the molecule was discussed on the basis of data given by Schmidt and Quade. The potential barrier of the mercapto internal rotation was obtained from splittings of the observed spectra. The Fourier coefficients of this barrier are V1=−207±67, V2=−386±27, and V3=1305±20 cal/mol. The spectra due to the excited methyl and mercapto torsional states were also measured for the trans and gauche isomers. The potential barrier of the methyl internal rotation for the trans isomer was found to be 3260±30 cal/mol from splittings of the spectra due to the first excited methyl torsional state.
The Polarography of the Cadmium(II)–2-Carboxy-1-pyrrolidinecarbodithioate Chelate
Authors: Kitagawa Toyokichi , Nomura Kazuo
Published: July 2006

The electrochemical behavior of the cadmium(II) ion in the presence of 2-carboxy-1-pyrrolidinecarbodithioic acid (H2cpcd) as a chelating agent was investigated in an alkaline medium by d.c. polarography, a.c. polarography, cyclic voltammetry, and chronopotentiometry. The cadmium(II) chelate gave a reversible two-electron reduction wave at −0.86 V vs. SCE, with a postwave at −0.95 V. From the dependence of the total wave height on the mercury column height and from the methods of cyclic voltammetry, the electrode reduction of the cadmium(II) chelate was found to be diffusion-controlled. The diffusion current constant was 2.42 μA mol−1 m3 mg−2⁄3 s1⁄2. The postwave was identified as an adsorption wave of the cadmium(II) chelate from the dependence of the postwave height on the mercury column height, the a.c. peak height, the electrocapillary curves, and the results of chronopotentiometry. The surface excess of cadmium(II) chelate adsorbed on the mercury electrode was evaluated by means of three different electrochemical techniques. The composition of the cadmium(II)–cpcd chelate in the presence of excess H2cpcd was Cd(cpcd)22−, and the overall stability constant was estimated to be 8.0×1012 at 25.0 °C and μ=1.5.
XPS Study on the Charge Distribution in Chromium(0) Complexes
Authors: Kinomura Fumio , Tamura Tadashi , Watanabe Iwao , Yokoyama Yu , Ikeda Shigero
Published: July 2006

Binding energies of core electrons in Cr(C6H6)2, Cr(C6H6)(CO)3, and Cr(CO)6 were measured by means of X-ray photoelectron spectroscopic method in solid phase. By comparison with their UPS spectra observed in gasous phase, binding energies referred to vacuum level can be obtained. On the basis of this result, charge distribution in these complexes are estimated. The intramolecular relaxation energy of Cr(C6H6)2 is also discussed.
A Macrocyclic Enzyme Model System. An Electrostatic-Hydrophobic Double-Field Catalysis by a [20]Paracyclophane in the Deacylation of p-Nitrophenyl Hexadecanoate
Authors: Murakami Yukito , Aoyama Yasuhiro , Dobashi Kazuyuki , Kida Masaaki
Published: July 2006

The catalytic functions of 10-oxo[20]paracyclophanyl-22(23)-methyltrimethylammonium chloride (1) in the hydrolysis and aminolysis reactions of p-nitrophenyl hexadecanoate (PNPP) were investigated in 1%(v/v)methanol–1%(v/v)dioxane-water over the pH 9–10 region at 40.0 °C and μ=0.2 (NaCl) with the initial PNPP concentration of 1.00×10−5 M. The paracyclophane (0.88×10−5 M) accelerated the hydrolysis of PNPP by one order of magnitude at pH 9.7. The presence of either ethanolamine or glycine in the 1-catalyzed deacylation of PNPP resulted in further rate enhancement. The rate enhancement was brought about by the aminolysis reaction of PNPP with the amines as confirmed by the product analysis. The greater reactivity of glycine relative to that of ethanolamine was attributed to the electrostatic interaction between the anionic carboxylate group of glycine and the cationic ammonium group of 1. The novel electrostatic-hydrophobic double-field catalysis was discussed for the glycinolysis reaction.
Metal-Assisted Terpenoid Synthesis. IV. Nickel-Catalyzed Reactions of 1,3-Dienes with Ketones. A New Synthesis of Long Chain Tertiary Alcohols
Authors: Akutagawa Susumu
Published: July 2006

Catalytic reactions of 1,3-butadiene with ketones were carried out with a nickel-ligand system to give stereoselectively tertiary alcohols having a (2Z, 5E)-2,5,7-octatrienyl- or a (2Z, 6E, 9E)-2,6,9,11-dodecatetraenyl chain. Similar reactions of isoprene gave a mixture of terpenic and apoterpenic alcohols. A possible reaction scheme was discussed in terms of an insertion of the carbonyl group to a σ-allyl end of octadienyl or dodecatrienyl nickel complexes.
Formation of Excited Molecules and Atoms by Controlled Electron Impact on Hydrogen Chloride and Chlorinated Methanes
Authors: Toyoda Minoru , Ogawa Teiichiro , Ishibashi Nobuhiko
Published: July 2006

The dissociation, ionization, and excitation of hydrogen chloride and chlorinated methanes under controlled electron-impact excitation were studied at low pressures. The photoemissions (200–600 nm) were observed and assigned to HCl+, CH, CH+, CCl, H, and Cl+. Such species as H and HCl+ from HCl, and H and CH from CH2Cl2 were concluded to be produced by some one-electron processes. The photoemission of the HCl+ produced from CH2Cl2 increases quadratically with the electron-beam current; in this case HCl+ is mainly produced by the molecular elimination of HCl and the successive ionization excitation by the second electron. The threshold energies of the photoemissions were found to be 16.8 eV for HCl+* from HCl, 19.8 eV for H* from HCl, and 17.6 eV for CH*(A) from CHCl3. The processes of the excitation of these species near the threshold were discussed.
Formation of Diacetylene Ion (A2Πu) by Controlled Electron Impact on Unsaturated Molecules
Authors: Tsuji Masaharu , Ogawa Teiichiro , Imasaka Totaro , Nishimura Yukio , Ishibashi Nobuhiko
Published: July 2006

By the impact of an electron beam (100–450 eV) on aliphatic hydrocarbons (C2H2, C2H4, C4H6), cyclo-octadienes, and aromatic molecules (C6H6, C10H8, C12H10, etc.) at about 10−3Torr, the Schüler’s T spectrum of diacetylene ion (A2Πu–X2Πg) was observed in the 505–570 nm region, in addition to the well-known systems of H(Balmer), CH(A–X), and C2(Swan). Three different kinds of mechanisms for the formation of C4H2+ (A) were derived from the dependence of the emission intensity on the electron-beam current and the gas pressure: (a) the primary excitation process (C4H6), (b) the secondary excitation process (aromatic molecules, cyclooctadienes), and (c) the dimerization excitation process (C2H2, C2H4). The intensity ratio (C4D2+/C4H2+) of the T spectrum from C6H6 and C6D6 was 0.83±0.04 for the (0,0) sequence at 300 eV excitation.
Conformation of Thymidine 3′,5′-Cyclic Phosphate in Aqueous Solution. Compatibility of the Information from the Lanthanide-Ion Probe and the Spin-Coupling Constants
Authors: Inagaki Fuyuhiko , Takahashi Seizo , Tasumi Mitsuo , Miyazawa Tatsuo
Published: July 2006

The Pr(III)- and Eu(III)-induced shifts of 1H nuclear magnetic resonances of thymidine 3′,5′-cyclic phosphate were observed in D2O solution. The results indicated that the induced shifts were primarily of dipolar origin and that the magnetic susceptibility tensor had effective axial symmetry. The ratios of shifts intrinsic to the lanthanide-substrate 1 : 1 complex were determined after correcting for the contributions of the complex formation shifts (diamagnetic terms). The Gd(III)-induced perturbations of the spin-lattice relaxation times were also observed, and the ratios of relaxation rates were obtained. A computer search was then performed to find out the molecular conformation of this cyclic nucleotide which best fitted the shift and relaxation ratios. As a result the phosphate-ring part was found to have a typical chair conformation. The effective symmetry axis of the magnetic susceptibility tensor coincided with the bisector of the OPO angle almost completely. It was rather difficult, however, to establish the conformation of the deoxyribose ring from the shift and relaxation ratios alone. The use of the additional information from the vicinal 1H–1H coupling constants (J1′2′ and J1′2″) was necessary for obtaining a reasonable conformation of the entire molecule. The compatibility of the information from the lanthanide-ion probe and the spin coupling constants (3JHH other than J1′2′ and J1′2″ and 3JHP) is discussed along with the limitations of both methods.
Formation of Oxygen Deficient Pyrochlore Solid Solutions Pb2Ta2−2xM2xO7−x(M=Ti, Sn and Zr) and Their Optical and Dielectric Properties
Authors: Torii Yasuyoshi , Matsumoto Hideo
Published: July 2006

It was found that oxygen deficient pyrochlore solid solutions Pb2Ta2−2xM2xO7−x with M=Ti, Sn, and Zr exist over wide ranges. The formation of oxygen deficient pyrochlore structure results from the occupancy of Pb2+ ions in the A position, which have a high polarizability. Their reflectance and infrared absorption spectra, and dielectric constants were measured. With the increase of M4+ ions, the color turned lemon yellow to reddish yellow, and the dielectric constants increased. The infrared absorption spectra in their pyrochlore solid solutions were similar to those in PbTiO3 and PbZrO3. The infrared properties of two strong absorption bands observed were discussed in comparison with those in the perovskites.
The Catalytic Action of a Mixed Micelle of Lauroylamino Acid and a Detergent
Authors: Inoue Tohru , Nomura Kazuo , Kimizuka Hideo
Published: July 2006

The catalytic effect of the mixed micelles of lauroylamino acids (LauAm) and detergents on the hydrolysis of p-nitrophenyl acetate has been studied. The amino acids used for the synthesis of LauAm were glycine, serine, histidine, tyrosine, lysine, and arginine. Cetyltrimethylammonium bromide (CTAB), polyoxyethylene dodecyl ether (C12E6) and sodium dodecyl sulfate (SDS) were used for the preparation of the mixed micelles with LauAm. Among the detergents used, only CTAB remarkably enhanced the catalytic activity of LauAm. A reaction scheme was proposed, and the rate constant for the catalytic activity of LauAm was estimated from the kinetic data. The effect of pH was also studied. Discussions were given of the mechanism of the catalytic action on the basis of the present study.
Furan Derivatives. II. The Cyclization of 3-(Benzofuran-3-yl)propionic Acid Derivatives
Authors: Horaguchi Takaaki , Shimizu Takahachi , Abe Teishiro
Published: July 2006

A compound, 6-methoxy-2a,3,4,5-tetrahydro-2H-naphtho[1,8-bc]furan-5-one (XX), was prepared in a 72% yield by heating 3-(5-methoxy-2,3-dihydrobenzofuran-3-yl)propionic acid (XIX) with polyphosphoric acid. However, when 3-(5-methoxybenzofuran-3-yl)propionic acid (IX) or 3-(2-benzoyl-5-methoxybenzofuran-3-yl)propionic acid (XIII) were treated with polyphosphoric acid, the product was 7-methoxy-2,3-dihydro-1H-cyclopenta[b]benzofuran-3-one (XI) rather than the corresponding naphtho[1,8-bc]furan derivatives, Also, neither naphtho[1,8-bc]furan nor cyclopenta[b]benzofuran derivatives were obtained from 3-(2-benzyl-5-methoxybenzofuran-3-yl)propionic acid (XIV) or 3-(2-ethyl-5-methoxybenzofuran-3-yl)propionic acid (XVII).
The Catalytic Effect of Crown Ethers on Benzoin Condensation
Authors: Akabori Sadatoshi , Ohtomi Michiko , Arai Katsuhiko
Published: July 2006

Aromatic aldehydes were treated with potassium cyanide in the presence of a crown ether in water or in aprotic solvents to give benzoins in high yields, although similar reactions in the absence of the crown ether proceeded sluggishly in general. The catalysis is believed to be due to the ability of the crown ether to bring anions into the organic phase.
The Thermal Reaction of Azoxybenzenes
Authors: Shimao Ichiro , Hashidzume Hirokazu
Published: July 2006

Azoxybenzenes (1) were heated at 245–250 °C to give azobenzenes (2), 2-hydroxyazobenzenes (3), 2-hydroxy-azoxybenzenes (4), 4-hydroxyazobenzenes (5), and 4-hydroxyazoxybenzenes (6). Compounds 4 and 6 were mostly composed of α-isomers. In the reaction of azoxytoluenes, their methyl groups were oxidized to formyl groups. It was proposed that 4 and 6 were the intermediates of the thermal rearrangement of 1 to 3 and 5.
The Crystal Structure of 1-(2-Thiazolylazo)-6-bromo-2-naphthol
Authors: Kurahashi Masayasu , Fukuyo Makoto , Shimada Akira , Kawase Akira
Published: July 2006

The crystals of 1-(2-thiazolylazo)-6-bromo-2-naphthol are orthorhombic, with a space group of P212121, and with unit-cell dimensions of a=19.044(3), b=31.996(9), c=4.221(1) Å, and z=8. The crystal structure was solved by the heavy-atom method and refined by the least-squares technique to give an R value of 0.064 for 1608 observed reflections. Both of the two crystallographically independent molecules show a generally similar shape and size. The phenolic oxygen atom is linked to the azo nitrogen atom adjacent to the thiazole ring by intramolecular hydrogen bonding, the O···N distances being 2.54 Å.
ESR Studies of Nitrobenzene Ion-Pair Equilibria in N,N-Dimethylformamide
Authors: Toshima Shinobu , Itaya Kingo
Published: July 2006

The hyperfine splitting constants of the nitrobenzene radical anion in DMF vary with the type of the counter cations and the concentrations. The tendency of these variations is related to the shift of the half-wave reduction potential of nitrobenzene. The variation of the nitrogen 14N hyperfine splitting constant is attributable to the formation of ion pairs involving the nitrobenzene radical anion and its counter cation. The ion-pair formation constants were evaluated from the changes in the hyperfine splitting and are completely consistent with those obtained from polarographic studies.
The Differences in Surface and Catalytic Properties of Two Magnesium Oxides Prepared from the Hydroxide and the Carbonate Hydroxide
Authors: Hattori Hideshi , Shimazu Katsuaki , Yoshii Naoji , Tanabe Kozo
Published: July 2006

Two kinds of MgO were prepared; MgO(I) from magnesium hydroxide and MgO(II) from magnesium carbonate hydroxide by evacuating at various temperatures and their surface and structural properties and catalytic actions for alkylation and isomerization reactions were examined. IR spectra of CO2 retaining or adsorbed showed broad bands on MgO(II), but relatively sharp bands on MgO(I). In the alkylation of phenol with methanol over MgO(I), phenol was selectively alkylated at the ortho positions to produce o-cresol and 2,6-xylenol. The ortho-selectivity of MgO(I) was higher than 96%, while that of MgO(II) was about 75%. A low selectivity of MgO(II) was considered to be caused by a heterogeneity of surface structure of MgO(II), which was suggested by broad IR bands of CO2 species on MgO(II). For the isomerization of 1-butene, both of MgO became active when evacuated at 450 °C and showed maximum activities when evacuated at 600 °C. The activity and the selectivity (ratio of cis-2-butene to trans-2-butene) of both catalysts were not much different. However, for the isomerization of cis-2-butene, the maximum activity and the selectivity (ratio of trans-2-butene to 1-butene) of MgO (I) were about four times higher than those of MgO(II).
Preparations and Properties of Some Gationic Palladium(II) Complexes of the Di-t-butylnitroxide Radical
Authors: Okunaka Masaaki , Matsubayashi Gen-etsu , Tanaka Toshio
Published: July 2006

Cationic palladium(II) complexes of the di-t-butylnitroxide radical, [Pd(But2NO)(L-L)]X (L-L=2,2′-bipyridine, 1,10-phenanthroline, N-substituted 2-pyridylmethyleneamine and bis(triphenylphosphine); X−=ClO4-and/or BPh4−), were prepared. 1H NMR spectra of the complexes indicate that the nitroxide forms a three membered ring with the palladium atom. The N-methyl- and N-ethyl-2-pyridylmethyleneamine complexes exist as two geometrical isomers in solution, whose ratios are 1 : 1 and 1 : 0.2, respectively. In the N-butyl and N-p-tolyl analogs, however, only one of the isomers exists in solution. These results are interpreted in terms of steric repulsion between the t-butyl groups and N-substituents. The bipyridine complex reacts with dialkyl disulfides in the presence of catalytic amounts of bipyridine to give a sulfur-bridged dimeric complex, [Pd(bipyridine)(SR)]2(ClO4)2(R=Me and Pr), and a free nitroxide radical.
Photochemical Valence Bond Isomerization of Some Benzo-C9H10 Hydrocarbons
Authors: Kato Masahiko , Chikamoto Takeji , Miwa Toshio
Published: July 2006

Studies have been carried out on the photochemical valence bond isomerization of some benzobicyclo-C9H10 hydrocarbons, i. e., benzo[8,9]bicyclo[5.2.0]nona-2,4,8-triene (2), benzo[2,3]bicyclo[6.1.0]nona-2,4,6-triene (3), cis-3a,9b-dihydro-1H-benz[e]indene (6), and benzo[6,7]bicyclo[3.2.2]nona-2,6,8-triene (10), with use of a low pressure mercury lamp. From a comparison of photolysis at low temperatures with that at room temperature, the stereochemical courses are discussed in terms of conformations of these compounds.
The Application of the Spin Trap, Phenyl t-Butyl Nitrone, to the Study of the γ-Radiolysis of Cyclohexane
Authors: Iwahashi Haruo , Ishikawa Yo-ichi , Sato Shin , Koyano Kinko
Published: July 2006

It was shown that cyclohexyl radicals formed by the γ-radiolysis of cyclohexane were trapped by phenyl t-butyl nitrone (PBN) to give a nitroxide with a well defined ESR spectrum. We measured the yield of this nitroxide. In order to establish the radical and electron scavenging properties of PBN, we measured the effect of this compound on the yields of hydrogen and nitrogen by adding dinitrogen oxide in cyclohexane together with PBN. The results suggested that PBN is able to scavenge not only free radicals but also electrons. The following relative rates were obtained: k(e−+PBN→PBN−)/k(e−+N2O→N2O−)=0.7 and k(H+PBN→HPBN)/k(H+C6H12→H2+C6H11)≈200 at room temperature. The G-value of the scavengeable hydrogen atoms from cyclohexane was estimated to be 3.4±0.4.
Dynamic Structure of Water in Aqueous Solutions of Chloroacetate. I. Temperature Dependence of Limiting Mobilities of Mono-, Di-, and Tri-chloroacetate Ions
Authors: Ebina Satoshi , Uedaira Hisashi
Published: July 2006

Electric conductivities of the sodium salts of mono-, di-, and tri-chloroacetic acids were measured in water at 15, 25, and 35 °C. The molar conductivities were analyzed by the Fuoss-Onsager equation to obtain the limiting mobility. On the basis of the temperature dependence of the limiting mobilities, the dynamic structure of Water around these anions was investigated by means of Samoilov’s theory, Chloroacetate ions are structure maker and the degree of the positive hydration is in the order TCA−>acetate ion>DCA−>MCA−. From the results, it is shown that a competition between the different orientation of water molecules in the surroundings of –CH2Cl and –CHCl2 groups occurs, and consequently, shown that the water molecules around DCA− and MCA− ions more mobile than those around TCA− and acetate ions.
Dialkylpalladium(II) Complexes. Syntheses, Characterizations, and Reactions with CO, I2, and CH3I
Authors: Ito Takashi , Tsuchiya Hirotaka , Yamamoto Akio
Published: July 2006

The reaction of bis(acetylacetonato)palladium(II), [Pd(acac)2] with AlR2(OEt) in the presence of tertiary phosphine, L, in diethyl ether yields a series of dialkylpalladium(II) complexes, [PdR2L2], where R=Me, Et, and Prn; L=PEt3, PPh2Me, and 1/2Ph2PCH2CH2PPh2 (dpe). These complexes were characterized by means of elemental analysis, IR and 1H-NMR spectra and of some decomposition reaction such as thermolysis and acidolysis. The trans- and cis-configurations of [PdMe2L2] (L=PEt3 and PPh2Me, respectively) in solution were established on the basis of the 1H-NMR spectra. The examination of 1H-NMR spectra in the presence of tertiary phosphine suggests the ligand exchange processes promoted by the added phosphine. [PdR2L2] (L=PEt3 and PPh2Me) reacted with CO in toluene to yield the quantitative amounts of the corresponding dialkyl ketones. The reactions of the complexes [PdR2L2] with iodine afforded [PdI2L2] and RI, and of [PdR2(dpe)] with MeI gave CH3H, CH3CH3, R(–H), RH, R·CH3, R·R, and RI together with [PdI2L2], suggesting the presence of a quadrivalent, six-coordinate intermediate palladium species.
Polarographic Studies of Several Metal Ions in the Molten Salts of KNO3–LiNO3–NaNO3
Authors: Saito Makoto , Miura Tamio
Published: July 2006

The polarographic waves of Pb(II), Cd(II), Zn(II), and Tl(I) ions in molten salts of KNO3–LiNO3–NaNO3 were measured by means of d.c. polarography, using an Ag/AgNO3 reference electrode. The half-wave potential of metal ions was shifted toward more negative values in comparison with those in a nitrate melt containing no Li(I) ion.
Simple Relations between Scattering Cross Sections and Molecular Diameters
Authors: Oono Yoshitsugu , Nishimura Yukio
Published: July 2006

Empirical linear relations between the square roots of the electron-scattering cross sections for molecules and the cube roots of the van der Waals volumes for molecules due to Bondi are shown. The relations allow one to estimate, for example, the electron-impact ionization cross sections at 75 eV to within an error of ±15%. A dimensional analytic explanation of the relations is given.
Studies on the Thermal Separation Column. V. Thermal Separation Column Having Horizontal Barriers
Authors: Sasaki Kazuo , Tao Seiji , Hirano Yoshio
Published: July 2006

The performance of a hot wire type thermal separation column in which many horizontal barriers of Teflon or copper plates are installed has been examined. At the optimum spacing of barrier plates, the quality factor defined by (2AL)barrier/(2AL)open exceeds 3. This means that a barrier column constructed properly has a performance equivalent to that of an open column of three times taller in height. Visualization of a stream line in the barrier assembly indicates that a helical transverse motion takes place in the space partitioned by two adjacent barrier plates.