bluuebunny/crossref_metadata_2025 huggingface dataset:
Counterion Effect in the Electron-Transfer Reactions between a Tetracyanoethylene Radical Anion and Its Neutral Molecule
Authors: Ogasawara Masaaki , Takaoka Hidetoshi , Hayashi Koichiro
Published: July 2006

The rates of homogeneous electron-transfer reactions between radical anions and neutral molecules were studied in a variety of tetracyanoethylenide systems in order to obtain information concerning the counterion effect on the electron-transfer reactions. The estimated values of the rate constants had the same order of magnitude at room temperature for all the systems, while the activation energies and the preexponential factors were markedly dependent on the natures of the counterions and the solvents. The obtained results are discussed in terms of the forms and structures of the radical anions.
Reaction between Methyl-p-tolylmethoxysulfonium Salt and Nucleophiles
Authors: Tsumori Kuniaki , Minato Hiroshi , Kobayashi Michio
Published: July 2006

The reactions of methyl-p-tolylmethoxysulfonium ion with such nucleophiles as tertiary amines, triphenylphosphine, thiophenolate anion and p-toluenesulfinate anion were investigated. The points of attack vary with nucleophile; the sulfonium ion receives nucleophilic attacks at its methoxy oxygen, methoxy carbon, sulfonium sulfur, S–CH3 hydrogen or O–CH3 hydrogen atoms. Optically active methyl-p-tolylmethoxysulfonium ion was also synthesized, and its reactions with benzylethylphenylamine, benzylmethylphenylphosphine and benzyl ethyl sulfide were studied. In the cases of the amine and the sulfide, the methylated products had optical activity. Thus, the methoxysulfonium ion can act as an optically active methylating agent.
Studies on Aminosugars. XXXV. Syntheses of 3′,4′-Dideoxyneamine and 3′- and 4′-O-Methylneamines
Authors: Jikihara Tetsuo , Tsuchiya Tsutomu , Umezawa Sumio , Umezawa Hamao
Published: July 2006

3′,4′-Dideoxyneamine and 3′- and 4′-O-methylneamines have been prepared from neamine via 5,6-O-cyclohexylidene-tetra-N-methoxycarbonylneamine (2).
The Methylenation of Several Allylbenzene-1,2-diol Derivatives in Aprotic Polar Solvents
Authors: Fujita Harushige , Yamashita Masataro
Published: July 2006

The aprotic polar solvents, such as DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide), accelerated very effectively the methylenation of 1,2-dihydroxy-4- (I), 1,2-dihydroxy-3,4-dimethoxy-5- (II), and 1,2-dihydroxy-3-methoxy-5-allylbenzene (III) in the presence of bronze and cupric oxide as catalysts.
Preparation of Reinforcing Fillers from Japanese Acid Clays with Lime and by Calcination. II. Optimum Conditions for the Preparation of Good Hard Clays and Evaluation of Their Reinforcing Properties
Authors: Rai Hideki , Yamada Junkichi
Published: July 2006

In order to find the optimum conditions for the preparation of good reinforcing filler from Matsune (M) and Nakajo (N) acid clays with lime and by calcination, investigations were carried out by changing the amount of alkali (1.25–60% CaO), the temperature of thermal treatment (110–800 °C) and the subsequent mechanical disintegration time (6–24 hr). The required conditions were found to be: amount of alkali, 3% for M and 6% for N; calcination at 600 °C for 1.5 hr; disintegration time around 18 hr. The deviation in the optimum amount of alkali was attributed to the difference of mineralogical constituents. The products pulverized gave the SBR-1502 compounds good reinforcing properties comparable to those of Dixie Clay. Investigation was also carried out on the influence of manual and mechanical mixing of the raw materials, the mode of disintegrating the calcined matter by either wet ball-milling or dry pulverization, and the effect of sieving the pulverized product in wet or dry state on the reinforcing properties of the prepared fillers. A variable loading test with hard clay M up to 150 PHR proved that its reinforcing properties are comparable to those of the reference filler. The maximum reinforcement for the elastomer was found to be about 50 PHR for hard clay M and about 100 PHR for the reference filler.
The Intensity in the Resonance Raman Effect. I. The Diatomic Molecule in the Harmonic Potential Approximation
Authors: Kobinata Shunsuke
Published: July 2006

The formulas for the Raman intensities of fundamental and n-th overtones were investigated theoretically, starting from the Kramers-Heisenberg dispersion formula and referring to a diatomic molecule in a harmonic potential approximation. The derived formulas were then applied to fifteen overtone bands of iodine, which have been observed in gas, and to the exciting frequency dependence of the fundamental and the first overtone intensities of iodine in a CHCl3 solution. It was shown that the formulas quantitatively explain the trend of the observed data well.
Polarographic Studies of Some Porphyrins and Metalloporphyrins in N,N-Dimethylformamide
Authors: Kakutani Tadaaki , Totsuka Shoji , Senda Mitsugi
Published: July 2006

Electrochemical behavior of protoporphyrin IX dimethylester (PPDM), mesoporphyrin IX dimethylester(MPDM), Fe(III)Cl-protoporphyrin, Ni(II)-, Cu(II)-, Co(II)-, Zn(II)- and Mn(III)Cl·H2O–PPDM was investigated in dimethylformamide by use of AC polarography, cyclic voltammetry and DC polarography. These porphyrins and divalent metal complexes of PPDM gave, for the most part, three reduction waves. The first and second waves were reversible one-electron steps in each case, but the third step was an irreversible one. Mn(III)-complex gave four reduction waves and one oxidation wave. The first three reduction waves were one-electron steps and the oxidation wave was identified as that due to chloride anion. Fe(III)-complex gave five reduction waves and one oxidation wave. The first two reduction waves were one-electron steps. All these compounds showed specific adsorption at the potential more positive than −1.1 V vs. SCE. Assignment of the reduction steps of the metalloporphyrins is described. The observed order of increasing negative half-wave potentials is discussed in terms of Zerner and Gouterman’s molecular orbital calculation.
Kinetics of Hydrogen Electrode Reaction on Mercury. I. Theoretical Part. Non-steady State Analysis for the Electrochemical Mechanism
Authors: Katayama Akiko , Kita Hideaki
Published: July 2006

Potentiostatic and potentiodynamic transients are theoretically analysed on the basis of the electrochemical mechanism for the hydrogen electrode reaction. The interface was assumed to consist of the metal surface, the plane on which the adsorbed intermediate of H2+(a) stays, and the diffuse double layer. The repulsive force between the intermediates was introduced by proportional approximation. From the results the depolarization observed in Tafel plots is understood as a non-steady state phenomenon, and observation by the potential-sweep method offers information on both the features of the adsorbed intermediate and the kinetics of the step preceding the rate-determining step.
Kinetics of Hydrogen Electrode Reaction on Mercury. II. Experimental Part. Elucidation of Non-steady State by Constant Potential and Linear Potential-sweep Methods
Authors: Katayama Akiko , Kita Hideaki
Published: July 2006

Potentiostatic and potentiodynamic experiments on Hg in 1 M HCl, HBr, and HI solutions were carried out to elucidate transient phenomena of the electrochemical mechanism of the hydrogen electrode reaction. The results obtained by both methods agree with the analysis of the non-steady state based on the electrochemical mechanism. The large effect of anions on the transient phenomena is satisfactorily interpreted by the change of repulsive force energy between H2+(a)’s on electrode, which is caused by the presence of specifically adsorbed anions in various degrees. The potential-sweep method reveals features of the step preceding the rate-determining step and gives the value of the repulsive force energy between H2+(a)’s as expected by the analysis.
Molecular-symmetry Reduction in CmHm−2 Cata-condensed Nonalternant Hydrocarbons
Authors: Toyota Azumao , Nakajima Takeshi
Published: July 2006

On the basis of the second-order Jahn-Teller effect and the semiempirical SCF MO method, we examined the energetically most favorable molecular-symmetry groups and geometrical structures with respect to C–C bond lengths of the CmHm−2 cata-condensed nonalternant hydrocarbons. In the 4n π-electron systems the first excitation energies in the fully-symmetrical nuclear arrangements were predicted to be significantly smaller than a certain critical value, and a molecular-symmetry reduction accompanied by a marked double-bond fixation in the peripheral carbon skeleton to occur. On the other hand, in the 4n+2 π-electron systems, such energies were found to be considerably large for small members and to decrease rapidly with the number of carbon atoms, resulting in the molecular-symmetry reduction for members larger than a certain critical size. The electronic spectra were calculated using the most stable geometrical structures obtained by the SCF MO method.
Electrochemiluminescence of 9,10-Dichloroanthracene at Low Temperatures
Authors: Matsumoto Tamotsu , Sato Masanori , Hirayama Satoshi
Published: July 2006

The electrochemiluminescence (ECL) of 9,10-dichloroanthracene in methylene chloride was investigated at temperatures as low as −60°C. The cation was quite stable and the anion was unstable at room temperature. The anion, however, increased its stability as the temperature decreased and below ca. −40°C it was essentially stable. Temperature was also found to have great influence on the relative intensity of the two spectral components of the ECL of 9,10-dichloroanthracene. By lowering the temperature the components at the longer wavelength increased strongly compared with the other component. When the ECL was observed by applying a rectangular potential, the intensities of the two components decayed exponentially with the same decay constant. Therefore, it was concluded that the emission at the longer wavelength originated not from the products of electrolysis but from the excimer and that the primary process to produce these two emissions was the same.
The Electronic Absorption Spectra of Würster’s Cation Radicals and Their Dimerization in Solution
Authors: Nakayama Shigeki , Suzuki Keisuke
Published: July 2006

The visible and ultraviolet absorption spectra of the p-phenylenediamine cation (PD+), the N,N-dimethyl-p-phenylenediamine cation (DMPD+), and the N,N,N′,N′-tetramethyl-p-phenylenediamine cation (TMPD+) in the presence and in the absence of an excess counter anion (X−=Br−, Cl−, and ClO4−) are studied at low temperatures. Analyses of the data show that these cation radicals are in an equilibrium represented by 2R++X−\ightleftharpoonsR++2X− (or, more exactly, 2R++0.7X−\ightleftharpoonsR++2(X−)0.7). It is found that the absorption maxima of the dimer and the value of the heat of dimerization are independent of the kind of counter anion. It is concluded that PD+ and DMPD+ form strong dimers (heat of dimerization, ΔH=−8.0 and −8.2 kcal/mol respectively) and that TMPD+ forms a relatively weak one (ΔH=−5.6 kcal/mol). The features of the dimer spectra reflect the strength of the interaction of the radical in the dimer. In a strong dimer, the spectrum in the low-frequency region consists of a strong intermolecular charge-transfer band (C band) and a weak local excitation band (R′ band), and the frequency shifts of the local excitation bands in the dimer (R′ and Y′ bands) from corresponding bands in the monomer (R and Y) are large. On the other hand, the spectrum in the weak dimer consists of relatively weak C and strong R′ bands, and the shifts of the R′ and Y′ bands are small. A model of the dimer is proposed in which the two cations are arranged in a parallel manner and are surrounded by the ionic atmosphere of the counter anions.
Photoelectron Spectra and Orbital Structures of Higher Alkyl Chlorides, Bromides, and Iodides
Authors: Kimura Katsumi , Katsumata Shunji , Achiba Yohji , Matsumoto Hiroshi , Nagakura Saburo
Published: July 2006

High-resolution photoelectron spectra of alkyl halides RX (R=ethyl, n-propyl, and n-butyl; X=C1, Br, and I) were measured with the 584 Å line of helium. In the region below about 17 eV, six bands were observed for each of the ethyl halides, eight bands for each of the n-propyl halides, and ten bands for each of the n-butyl halides. All the observed vertical ionization energies were plotted against Pauling’s electronegativity of the halogen atom, indicating that there are approximate linear relationships. Assuming Koopmans’ theorem, total and partial sums of experimental orbital energies were calculated using the observed ionization energies for the individual alkyl halides and found to be well reproduced by calculating the sums of empirical orbital-energy values for several localized orbitals such as n(X.), n′(X), σ(C–X), σ(C–C), π(CH3), π′(CH3), and π(CH2). From a comparison of the experimental and calculated partial orbital-energy sums, assignments of the photoelectron bands to the localized molecular orbitals were made for each of the alkyl halides.
Ion-selective Electrode Membranes Responsive to Maleic and Phthalic Acids
Authors: Jyo Akinori , Yonemitsu Morihisa , Ishibashi Nobuhiko
Published: July 2006

Ion-selective electrodes responsive to maleic and phthalic acids were prepared. The organic solvent solution of the ion-pair of the objective monovalent acid anion with a Crystal Violet or a tris(bathophenanthroline)-iron(II) ion was used as the electrode membrane. The responses of both electrodes were linear down to 10−4–10−4.5 M, with an ideal Nernstian slope of 57–58 mV per activity decade at 20 °C. Together with the potential slope, the pH dependence of the potential showed that the electrode responded to the monovalent anion of maleic or phthalic acid. The interferences of acetate, benzoate, and chloride were extremely low, whereas iodide and perchlorate interfered greatly. The maleic acid electrode works well without the interference of fumaric aicd. The phthalic acid electrode also functions without any interferences by isophthalic or terephthalic acid.
Derivatographic Studies on Transition Metal Complexes. XII. Thermal Olation of Hydroxoaquo Cobalt(III) and Chromium(III) Complexes Containing Amino Acids in Solid Phase
Authors: Tsuchiya Ryokichi , Uehara Akira , Kyuno Eishin
Published: July 2006

The thermal olation of the following four types of complexes in a solid phase was investigated by means of derivatography: 1) cationic complexes, [Co(OH)(n3-o)(H2O)]X, 2) anionic complexes, M[Co(OH)(n-o3)-H2O)], 3) double complexes, [Co(OH)(n3-o)(H2O)][Co or Cr(OH)(n-o3)(H2O)] and 4) neutral complexes, [Co(OH)(n-o)2(H2O)], where n3-o, n-o3 and (n-o)2 denote gly-en (glycinate ion and ethylenediamine) or dtma (diethylenetriaminemonoacetate ion), the analogues of nta (nitrilotriacetate ion) and α-amino acid ions, respectively. The thermal data such as initiation temperature, enthalpy change and activation energy of the olation were estimated from the respective derivatograms. From the results the effect of various ligands or counter ions (outer-sphere ions) on the olation was discussed.
Pressure Effect Determined with Use of the Nondispersive Infrared Gas Analyser
Authors: Niki Eiji , Yonezawa Tsutomu
Published: July 2006

The pressure effect of nitrous oxide and nitric oxide due to nitrogen gas was investigated with use of a nondispersive infrared gas analyser. The results are in line with the theoretical curves derived from the Elsasser theory. The calculated expression is partly improved and the error of calculations is estimated in regard to carbon dioxide.
Infrared Spectra of Some Transition-metal (Fe, Co, Ru, and Ir) Nitrosyl (14NO and 15NO) Complexes
Authors: Miki Eiichi , Mizumachi Kunihiko , Ishimori Tatsujiro , Okuno Hisateru
Published: July 2006

Twelve 15NO-complexes of iron, cobalt, ruthenium, and iridium were prepared. The correlations of the isotopic shifts of their IR spectra with a metal–(NO) bond angle were investigated. For several nitrosyl complexes, the absorption bands due to the skeletal vibrations between the metal and the NO group were clearly assigned. Of the two absorption bands in the region 250–650 cm−1, the absorption band with a smaller isotopic shift could be assigned to the metal–(NO) stretching vibration and that with a larger isotopic shift to the metal–(NO) bending vibration.
The Polarized Absorption Spectra of Some β-Substituted Anthraquinones
Authors: Inoue Hiroyasu , Hoshi Toshihiko , Yoshino Junko , Tanizaki Yoshie
Published: July 2006

The polarized absorption spectra of 2-hydroxy-, 2-amino-, and 2,3-diaminoanthraquinones were measured in stretched PVA sheets below 47 kK, and semiempirical ASMO-SCF-CI calculations, including the variable β method, were carried out for these compounds. By a comparison of the observed and the calculated results, the π–π* bands of these compounds were assigned. Each of these compounds has six bands in the observed wave number region, four of which correspond to those of anthraquinone; the other two bands can be assigned to the intramolecular charge-transfer transitions.
Synthesis of Anomeric Methyl 6-O-(l-Mycarosyl)-β-d-glucosaminides and 4-O-(l-Mycarosyl)-β-d-mycaminosides
Authors: Koto Shinkiti , Yago Kazuo , Zen Shonosuke , Omura Satoshi
Published: July 2006

Condensation of 3,4-O-carbonyl-2,6-dideoxy-3-C-methyl-l-ribohexopyranosyl chloride (III) with methyl 2-deoxy-2-(2,4-dinitroanilino)-β-d-glucopyranoside and the subsequent removal of blocking groups gave the anomeric isomers of methyl 6-O-(2,6-dideoxy-3-C-methyl-l-ribohexopyranosyl)-2-amino-2-deoxy-β-d-glucopy-ranoside (VIIa, VIIb). On the other hand, the condensation of III with methyl 3,6-dideoxy-3-(N-methylcarboethoxyamino)-2-O-p-phenylazobenzoyl-β-d-glucopyranoside (XI) followed by removal of the acyl groups and N-methylation afforded the anomeric forms of methyl 4-O-(2,6-dideoxy-3-C-methyl-l-ribohexopyranosyl)-3,6-dideoxy-3-dimethylamino-β-d-glucopyranoside (XVa, XVb).
Photochemical Rearrangement of 2-Nitrophenyl Phenyl Sulfoxide to 2-Nitrosophenyl Phenyl Sulfone
Authors: Tanikaga Rikuhei , Kaji Aritsune
Published: July 2006

Irradiation of 2-nitrophenyl phenyl sulfoxide (I) gave 2-nitrosophenyl phenyl sulfone (II) as the sole product. The rearrangement was not affected by a quencher, but took a different course in the presence of a sensitizer or a halogen-containing solvent. When I with an electron-donating substituent at a 4′-position or electron-withdrawing one at a 4-position was irradiated, the corresponding II was obtained in a lower yield. 2-Nitrophenyl phenyl sulfide was photochemically stable. From the results, it is proposed that in the excited singlet state of I the oxyanion of a nitro group attacks the positive sulfur atom, and oxygen transfer takes place.
Behavior of 2-Pyrazolin-5-ones toward Activated Double Bond Systems: Cyanoethylation of 2-Pyrazolin-5-ones
Authors: Elnagdi Mohamed Helmi , Ohta Masaki
Published: July 2006

3-Methyl-2-pyrazolin-5-one(Ia) reacts with acrylonitrile to yield either 4,4-di(β-cyanoethyl)-5-hydroxy-3-methylpyrazole(IV) or 1,4,4-tri(β-cyanoethyl)-3-methyl-2-pyrazolin-5-one(V) depending on the amount of reagent and the reaction conditions. Ia reacts with ethyl acrylate or crotononitrile to yield the 4-alkylated derivatives VIII and IX respectively. 3-Methyl-l-phenyl-2-pyrazolin-5-one(Ib) reacts with acrylonitrile to yield only 4,4-di(β-cyanoethyl) derivative XII which on hydrolysis affords the corresponding dicarboxylic acid (XIII). 3-Amino-1-phenyl-2-pyrazolin-5-one(Ic) adds to two molecules of ethyl acrylate or acrylonitrile to yield the 4,4-disubstituted derivatives XIV and XV, but only to one molecule of benzalacetophenone to yield the 4-substituted 3-amino-2-pyrazolin-5-one derivative XVIII. The pyrazolopiperidine derivative(XVI) was obtained on treatment of Ic with ethyl crotonate in the presence of sodium ethoxide.
Synthetic Studies of Bacitracin. IX. Synthesis of Peptide Fragments for Bacitracins of Cycloheptapeptide Formula
Authors: Munekata Eisuke , Shiba Tetsuo , Kaneko Takeo
Published: July 2006

In the synthetic study of bacitracins, peptide fragments corresponding to a branched part of bacitracin F, i.e., (S)-2-(2-methylbutyryl)thiazole-4-carboxylic acid 1-succinimidyl ester (III) and l-leucyl-γ-t-butyl-d-glutamyl-l-isoleucine (IV), were prepared. As a macrocyclic part of bacitracin A and F of cycloheptapeptide formula, cyclo- (Nα-benzyloxycarbonyl-l-lysyl-Nδ-cyclopentyloxycarbonyl-d-ornithyl-l-isoleucyl-d-phenylalanyl-l-histidyl-β-benzyl-d-aspartyl-l-asparaginyl) (V) was synthesized through cyanomethyl ester method.
The Reaction of β-Lactones with Acid Chlorides Catalyzed by Aluminum Chloride
Authors: Nakabayashi Tadaaki , Tanaka Yumo , Ito Suketaka
Published: July 2006

Aluminum chloride-catalyzed reactions of β-lactones with acid chlorides were studied. 3-Propanolide and 3-methyl- and 2-methyl-3-propanolide all undergo predominantly the O-alkyl bond fission to give mixed anhydrides of β-chloropropionic acid. The reaction was postulated to proceed via dichloraluminum β-chloropropionate.
Effect of Pressure on the Rate of Solvolysis. Formolysis and Methanolysis of Secondary Alkyl Tosylates
Authors: Sera Akira , Yamagami Chisako , Maruyama Kazuhiro
Published: July 2006

The effect of pressure on the formolysis and methanolysis rates of representative secondary alkyl tosylates was investigated, and the activation volumes, ΔV0\eweq, were estimated. The values of activation volume for formolysis were found to correlate excellently with σ*. This conformity of ΔV0\eweq to the Hammett-type correlation is interpreted as a consequence of the kc-character of the reaction. The values of activation volume for methanolysis, however, converged to more negative values. The ks-character of methanolysis is thought to be responsible for this behavior. The kc-ks-hybrid nature of the reaction is also discussed.
Photochemical Reduction of Thiobenzophenone. Reduction by Dihydroaromatic and Related Compounds
Authors: Ohnishi Yutaka , Ohno Atsuyoshi
Published: July 2006

Photochemical reduction of thiobenzophenone by 1,4-dihydrobenzene, 1,4-dihydronaphthalene, 9,10-dihydroanthracene, 1,3,5-cycloheptatriene, and acridane was studied. Relative reactivities and product analyses have revealed that the reaction is initiated by hydrogen-abstraction (one-electron-transfer followed by a proton migration) with thiobenzophenone in the n,π* triplet state. Inability of diphenylmethane to undergo the reaction can be interpreted by means of this mechanism.
The Distribution of 2-Thenoyltrifluoroacetone between Several Organic Solvents and an Aqueous Solution and Its Extraction of Sodium (I) into Methyl Isobutyl Ketone
Authors: Sekine Tatsuya , Takahashi Yoshihiro , Ihara Naohiko
Published: July 2006

Aqueous solutions containing sodium hydroxide and sodium perchlorate at various mixing ratios, 1 m Na-(OH, ClO4), were equilibrated with several organic solvents containing 2-thenoyltrifluoroacetone (TTA) at 25°. From the measurements of the hydrogen-ion concentration of the aqueous phase, the (KD+l)Ka−1 values, where KD is the distribution constant and Ka is the acid dissociation constant of TTA, were obtained; they were, 107.17(hexane), 107.74 (CCl4), 108.01 (C6H6) and 108.17 (CHCl3). From the values of KD obtained in another study, the value of Ka was determined to be 10−6.28. However, a much lower value than that expected was obtained for the MIBK system; this was due to the extraction of sodium (I) with TTA. The extraction was also confirmed by the distribution experiments of sodium (I). The extraction constant, Kex=[NaA]org/[Na+] [A−] (where A− is the TTA anion), was found from these results to be 100.86 in 1 M NaClO4 and 100.79 at an infinite dilution.
The Isomerization of Propylene Oxide on Metal Oxides and Silica-Magnesia Catalysts
Authors: Okamoto Yasuaki , Imanaka Toshinobu , Teranishi Shiichiro
Published: July 2006

The isomerization of propylene oxide was carried out over silica-magnesia catalysts and metal oxides at 260–270°C using a pulse reactor. The main products of the reaction were propionaldehyde, acetone, allyl alcohol, 1-propanol, and acrolein. Propionaldehyde and acetone are produced on acidic and basic sites respectively. Allyl alcohol is formed over acid-base bifunctional catalysts. 1-Propanol and acrolein are mainly produced through hydrogen-transfer reactions between allyl alcohol and propionaldehyde and propylene oxide. As regards these reactions, acid-base bifunctional catalysts are favorable and the reaction rate depends on the electron-donating power of the hydrogen acceptor and the basic strength of the catalyst. The acid sites on silica-magnesia catalysts are attributed to the forsterite produced by the reaction of magnesium oxide and silica gel, and the basic sites, to the magnesium oxide remaining. The metal oxides, such as magnesium and calcium oxides, are considered to have very weak acid sites.
Diffusion Coefficients of Bolaform Electrolytes in Aqueous Solution
Authors: Uedaira Hisashi
Published: July 2006

The diffusion coefficients of sodium salts of m-benzene disulfonate, 1,5-naphthalenedisulfonate, 1,2-ethanedisulfonate, and 1,4-butanedisulfonate in aqueous solutions were measured at 25°. The concentration dependence of the diffusion coefficients for sulfonates decreased with increasing charge distance and was smaller than that of the corresponding ordinary 2 : 1 electrolytes. The concentration dependence of diffusion coefficient for sodium m-benzenedisulfonate was the largest. It is shown that bolaform electrolytes behave like normal 1 : 1 electrolytes in the concentration range where the ion atmosphere around each charged group is independent.
The Electronic Absorption Spectra and Electronic Structures of Aromatic Azides, Nitrenes, and Diazonium Ions
Authors: Kashiwagi Hiroshi , Iwata Suehiro , Yamaoka Tsuguo , Nagakura Saburo
Published: July 2006

Electronic spectra were measured for azidobenzene, 1-azidopyrene, benzenediazonium ion, and 1-pyrenediazonium ion at room temperature, and also for nitrenobenzene and 1-nitrenopyrene at liquid nitrogen temperature. The π-electron structures of these compounds were calculated by the Pariser-Parr-Pople LCAO SCF MO CI method for the closed-shell systems and by the restricted open-shell SCF MO CI method for the open-shell systems. The calculated transition energies and oscillator strengths could satisfactorily explain the observed spectra. It was shown that the π-electron structures of azidobenzene and nitrenobenzene are similar to those of dimethylaniline and the benzyl or anilino radical, respectively.
The Electronic States of Tetracyanoethylene and Its Anion Radical as Studied by Their Infrared Spectra
Authors: Iida Yôichi
Published: July 2006

The infrared spectra of tetracyanoethylene (TCNE) and its anion radical in the rock-salt region were examined in order to observe any appreciable frequency differences between their corresponding bands. The vibrational assignments were made, and the basic Urey-Bradley force field was determined for the TCNE anion radical. By comparing them with those of the neutral TCNE, we discussed the difference in the electronic states between the neutral TCNE and its anion radical. The half-occupied molecular orbital of the TCNE anion radical was found to belong to the B2g irreducible representation.
Anodic Oxidation of Benzoic Acid in Nitriles
Authors: Matsuda Yoshiharu , Kimura Kazuo , Iwakura Chiaki , Tamura Hideo
Published: July 2006

The anodic oxidation of benzoic acid in acetonitrile and propionitrile was studied. Electrolysis was employed under a controlled potential or current. Benzoic acid was changed into an intermediate benzoyloxy radical through de-electronation in acetonitrile, and the resulting radical was reacted with acetonitrile to give N-acetylanthranilic acid in a 38% yield under constant potential electrolysis. In propionitrile, the anodic oxidation gave N-propionylanthranilic acid, N-propionylbenzamide, and dipropionylamine. No Kolbe-type reaction was observed.
The Molecular and Crystal Structure of the p-Bromobenzoate of an Unusual Birch Reduction Product
Authors: Furusaki Akio , Hamanaka Nobuyuki , Matsumoto Takeshi
Published: July 2006

It has already been found that the Birch reduction of 1,1,4aα-trimethyl-2α-hydroxy-8-methoxy-1,2,3,4,4a,9-hexahydrophenanthrene affords a tetrahydro derivative, contrary to expectations. The present paper will describe the details of the molecular structure of the unexpected reduction product, as revealed by an X-ray crystal analysis of its p-bromobenzoate (racemate). The crystals are triclinic, with two molecules in a unit cell of the dimensions: a=11.155, b=18.123, c=5.912 Å, α=94°39′, β=111°35′, and y=90°42′. The space group is P\bar1. The intensity measurement was made on an automatic four-circle diffractometer with CuKα radiation. The structure was solved by the heavy-atom method, and was refined by the block-diagonal-matrix least-squares method, anisotropic thermal motions being assumed for all the non-hydrogen atoms. From a difference map, twenty-six of the thirty-one hydrogen atoms were also found. The final R factor was 6.5%. As a result of the present study, it has been found that the C ring of cyclohexene-type shows an unusual behavior. The length of the C–C single bond opposite to the double bond in this ring is found to be only about 1.34 Å. This remarkable shortening seems to be due to special vibrations of the two atoms concerned. The whole cyclohexene ring takes a considerably flattened, half-chair form.
The Coordination Bonding and Stability of the 1 : 1 Complexes of Copper(II) with Various Bidentate Ligands in Aqueous-methanolic Solutions
Authors: Yokoi Hiroshi , Otagiri Masaki , Isobe Taro
Published: July 2006

ESR and spectrophotometric studies have been made of a number of 1 : 1 complexes of copper (II) with ethylenediamine, its analogues, and amino acids in aqueous-methanolic solutions. It has been shown that the complexes in the solutions are characteristic of copper(II) ions with a normal tetragonal environment and that their metal-ligand bondings are intermediate in the degree of covalency between those of hydrated cupric ions and the corresponding 1 : 2 complexes. The disproportionation constants and their temperature dependences, determined for the 1 : 1 complexes by the ESR and spectrophotometric methods, have been discussed, with particular empahsis on the fact that those values are in fair agreement with those derived from the step-by-step formation constants and the thermodynamic data obtained in aqueous solutions in the literature.
ESR Studies of Dimer Formation by the β-Diketone Chelate Complexes of Copper(II) in Toluene
Authors: Yokoi Hiroshi , Isobe Taro
Published: July 2006

A study of the ESR spectra of several β-diketone chelate complexes of copper(II) in the frozen solution of toluene has revealed that triplet-state dimers are formed at high concentrations in the solution and that these dimers are in equilibrium with only the monomers. The approximate equilibrium constants have been determined by a careful analysis of the ESR spectra observed in various concentrations. Structures for the dimers have been suggested from magnetic parameters properly determined using a point dipole model.
Rocker-type DTA Apparatus for Fluid Samples
Authors: Tanaka Satohiro
Published: July 2006

A Rocker-type DTA apparatus, with agitation by rocking, has been developed for use in the thermal analysis of various fluid mixture systems. The heater block, with its assembled cells, is continuously rocked at 20 r.p.m. with a rocking of 180° angle. The glass cell has a volume of about 8 ml and is sealed by means of a burner with a sample of about 5 ml. Distilled water is used as the inert reference in the reference holder. Two thermocouples are inserted in each cell, one to determine the temperature difference and the other for sample temperature measurements. The double thermocouple gives a constant transition temperature of the sample over a wide range of heating rates. The apparatus is applied to solid-liquid and starch-water systems. Variables affecting the DTA thermogram of the K2Cr2O7–H2O system are investigated, and a method is established to correlate the DTA curve with the solubility curve for the system.
Nickel(II), Cobalt(II), Palladium(II) and Beryllium(II) Chelates of 2,4,6-Heptanetrione
Authors: Sagara Fumio , Kobayashi Hiroshi , Ueno Keihei
Published: July 2006

Divalent metal chelates of heptane-2,4,6-trione (H2daa) were synthesized and their structures were discussed. Nickel(II), cobalt(II) and palladium(II) ions gave Ni(Hdaa)2·2H2O, Ni2(daa)2·4H2O, Ni2(daa)2·4Py, Co(Hdaa)2·2H2O, Co2(daa)2·4H2O, Co2(daa)2·4Py, Pd(Hdaa)2 and Pd(Hdaa)2·2H2O respectively, while beryllium (II) ion unexpectedly gave bis (2-amino-2-heptene-4,6-dionato) beryllium (II) which resulted from an amino-derivative of the original ligand. Spectroscopic results suggested that the coordination structure of nickel(II) and cobalt(II) ions was octahedral hexacoordinate, that of palladium(II) ion square planar tetracoordinate and that of beryllium(II) ion tetrahedral tetracoordinate. NMR study of the palladium(II) chelate suggested partial enolization of an uncoordinated carbonyl group. It was also found that nickel, cobalt and platinum ions promoted catalytically the bimolecular-condensation of heptane-2,4,6-trione.
Calmagite: The Formation Constants of Zinc(II) Chelates and Its Use as a Metal Indicator
Authors: Nakagawa Genkichi , Wada Hiroko , Fujita Yoshio
Published: July 2006

The acid dissociation constants of Calmagite [1-(2-hydroxy-5-methylphenylazo)-2-naphthol-4-sulfonic acid] and the formation constants of zinc(II) chelates have been determined spectrophotometrically at 25°C and at the ionic strengths of 0.1 and 1.0. In an ammoniacal medium zinc forms mixed-ligand complexes with Calmagite (I3−) and ammonia (X); ZnIXn−. The formation constants of the zinc(II)-Calmagite chelates are logKZnI=11.75, logKZnI2=7.82, logKZnIXx=2.09, and logKZnIX2x=1.70 (μ=1.0). Calmagite is recommended as an indicator for the titration of zinc(II) with EDTA. The color transition of Calmagite is clearer and sharper, and the aqueous solution of the indicator is more stable, than in the case of Eriochrome Black T.
Selective Activation of Methylene or Methine Groups in Coordinated Dipeptide Schiff Bases
Authors: Uyama Osamu , Nakao Yasuo , Nakahara Akitsugu
Published: July 2006

Nickel(II) and cobalt(III) chelates of the Schiff bases derived from salicylaldehyde and dipeptides such as glycylglycine, glycylalanine and alanylglycine have newly been prepared. The reactivity of methylene or methine groups in the dipeptide moieties of those Schiff base chelates has been investigated on the basis of their PMR spectra in D2O. It has been confirmed that the methylene or methine protons of the N-terminal amino acid residue are more easily activated than those of the C-terminal amino acid residue.
On the Mechanism of the Acid Catalysis and New Activating Agents in the Fusion Reaction of an Acylated Sugar with a Purine Derivative
Authors: Sekiya Masao , Yoshino Teruo , Tanaka Hisayuki , Ishido Yoshiharu
Published: July 2006

An examination of the site where the acidic catalysts might strongly interact in the fusion reaction of a purine derivative with a fully-acylated sugar led to the conclusion that a purine derivative was activated by the interaction with the catalysts, and, moreover, resulted in the discovery of a new type of activating agent other than the acidic catalysts which had previously been known in the fusion method. In the presence of an excess amount of activating agents, e.g., p-nitrophenol, the condensation reaction of theophylline with 1,2,3,4,6-penta-O-acetyl-β-d-glucopyranose proceeded, even in the absence of p-toluenesulfonic acid, to give the corresponding nucleoside. Some of the activating agents were found to form molecular compounds with theophylline, and a few of the latter to afford the corresponding nucleoside similarly. A possible mechanism for the activation process of theophylline by the above agents was discussed.
The Reversible Acylation of β-Diketone with Acyl Chloride in the Presence of Aluminum Chloride
Authors: Matsui Kiyotada , Motoi Masatoshi , Nojiri Tetsuro
Published: July 2006

The treatment of acetylacetone (I) with n-butyryl chloride in the presence of aluminum chloride in nitrobenzene gave n-butyrylacetone and di-n-butyrylmethane at 45°C. The same products were obtained, along with n-butyric acid, when n-butyrylacetone or di-n-butyrylmethane was treated with acetyl chloride under analogous conditions. The reactions between I and benzoyl chloride and between benzoylacetone or dibenzoylmethane and acetyl chloride gave products consisting of I, benzoylacetone, dibenzoyl-, diacetylbenzoyl-, acetyldibenzoyl-, tribenzoyl-methane, and benzoic acid. These findings show that β-diketone can reversibly react with acyl chloride to form new β-diketones by way of the mixed triacylmethanes. The acylation mechanism is discussed.
The Transacylation between β-Diketone and Ester in the Presence of Aluminum Chloride
Authors: Matsui Kiyotada , Motoi Masatoshi
Published: July 2006

The reaction of acetylacetone with an equivalent of phenyl benzoate in the presence of 2 equivalents of aluminum chloride in nitrobenzene afforded benzoylacetone (26% yield), dibenzoylmethane (4%), and phenyl acetate (37%), together with small amounts of phenolic ketones at 45°C. The total yield, based on the acyl groups introduced into the β-diketones, is similar to the yield of the ester newly formed. Such a similarity, suggestive of a transacylation, was also observed both on the use of p-nitrophenyl benzoate and on the treatment of benzoylacetone with phenyl benzoate or on that of dibenzoylmethane with p-nitrophenyl acetate. The non-formation of triacylmethanes is a strong evidence for the transacylation reaction, in which β-diketones and some esters exchange acyl groups directly. The analogous treatment of acetylacetone with α-naphthyl benzoate produced phenolic ketones, such as 2-acetyl- and 4-acetyl-1-naphthol, and the same benzoylated ketones as above in yields of 30 and 32% respectively. The considerably higher ratio of the 2-acetyl to the 4-acetyl isomer than that from the Fries rearrangement of α-naphthyl acetate indicates that another transacylation is accompanied by a rearrangement proceeding through complexes different from those in the Fries rearrangement.
The Crystal Structures of Methylene Dibromide and Methylene Diiodide
Authors: Kawaguchi Takemi , Wakabayashi Akira , Matsumoto Mitsuhiro , Takeuchi Toru , Watanabe Tokunosuke
Published: July 2006

The crystal structures of methylene dibromide and methylene diiodide (Form II) have been determined by the X-ray diffraction method at about −90°C and about −20°C respectively. Both the crystals are isomorphous, with monoclinic space group C2h6–C2/c. Unit cells containing eight molecules have these dimensions: a=12.239(12), b=4.459(15), c=15.212(16) Å, and β=113.54(7)° for methylene dibromide, and a=13.346(3), b=4.720(90), c=16.479(5) Å, and β=114.48(8)° for methylene diiodide. The orientations of the methylene groups have been obtained by lattice-energy calculations.
Syntheses of New Arginine Derivatives as a Substrate for Trypsin or Papain
Authors: Nishi Norio , Noguchi Junzo
Published: July 2006

Two new enzymic substrates, tosyl-l(d or Dl)-arginine-p-nitroanilide (l-TAPA, d-TAPA, and Dl-TAPA) and acetyl-l(d or Dl)-arginine-p-nitroanilide (l-AAPA, d-AAPA, and Dl-AAPA) were synthesized by the route for benzoyl-l-arginine-p-nitroanilide (l-BAPA) reported previously. The previous method for synthesis of l-BAPA was then improved by the direct benzoylation of l-arginine-p-nitroanilide dihydrochloride (l-APA), into which Nα-benzyloxycarbonyl-Nω-nitro-l-arginine-p-nitroanilide was converted by the simultaneous removal of benzyloxycarbonyl and nitro groups with hydrogen fluoride. This route has the advantages of shorter reaction steps and a better over-all yield than in the case of the previous method. The method is also applicable to the synthesis of l(d or Dl)-AAPA, but it is hard to prepare l(d or Dl)-TAPA by the method.
The Reaction of Methyl 2-Dimethoxymethyl-3-methoxypropionate with Amidines
Authors: Nishino Takenori , Miichi Yoshiyuki , Tokuyama Kanji
Published: July 2006

The reaction of methyl 2-dialkoxymethyl-3-methoxypropionate with acetamidine has been reported to afford 2-methyl-4-hydroxy-5-methoxymethylpyriniidine (13a) by a different mode than the reaction of 2-dimethoxy-methyl-3-methoxypropionitrile (1), which affords dihydropyrimidopyrimidine (4). As the presence of this difference seemed to be somewhat curious from the viewpoint of the reaction mechanism, the reaction of methyl 2-dimethoxymethyl-3-methoxypropionate (7) with acetamidine was reinvestigated. The reaction products were 13a and acetamidinomethylpyrimidine (17a). Similar results were obtained by the reaction of 7 with benzamidine. As the compound 17 corresponds to 4, the reaction of 7 was concluded to proceed in a manner similar to that of 1; that is, no essential difference exists between the reactions of 1 and 7 with amidines.
The Structure of Shikokianidin, a Minor Component of Isodon shikokianus Hara
Authors: Isobe Takahiko , Kamikawa Tadao , Kubo Isao , Kubota Takashi
Published: July 2006

Shikokianidin from Isodon shikokianus Hara is formulated as structure (3) on the basis of chemical and spectroscopic evidence.
Studies on Amino-hexoses. XVII. Identification of the Deamination Products from d-Glucosaminitol
Authors: Bando Tomoyuki , Matsushima Yoshio
Published: July 2006

The nitrous deamination products of d-glucosaminitol were fractionated with a Dowex-1 free base column after the reaction mixture had been reduced with sodium borohydride. The chromatography gave discrete five peaks, four of which were identified as 2-deoxy-d-arabino-hexitol, 2-deoxy-d-ribo-hexitol, 2-hydroxymethyl-2-deoxy-d-arabino(or ribo)-pentitol and d-mannitol in a total yield over 90%. The nitrous deamination products fractionated with a Dowex-1 borate column were identified as 2-deoxy-d-arabino-hexose, 2-deoxy-d-erythro-3-hexulose, 2-hydroxymethyl-2-deoxy-d-arabino(or ribo)-pentose and d-mannitol. The formation of products other than d-mannitol was interpreted in terms of intramolecular rearrangement accompanying nitrous deamination.
The Photo-induced Addition of Acetic Acid to Cyclohexene Derivatives
Authors: Leong Ta-Yan , Imagawa Takeshi , Kimoto Koichi , Kawanisi Mituyosi
Published: July 2006

The irradiation of methyl 3-cyclohexene-1-carboxylate in acetic acid in the presence of benzene as a sensitizer yields methyl trans-4-acetoxycyclohexanecarboxylate predominantly, together with a small amount of methyl trans-3-acetoxycyclohexane-1-carboxylate; the corresponding cis-isomers are not detected. Under the same conditions, on the irradiation of dimethyl esters of cis- and trans-4-cyclohexene-1,2-dicarboxylic acids, the two possible isomers of acetic-acid adducts with respect to each starting substance are obtained. The irradiation of trans-8-oxabicyclo[4.3.0]non-3-ene gives the two possible acetic-acid adducts, whereas in the case of the irradiation of the cis-isomer, only two equatorially-substituted acetic-acid adducts are obtained. The structural elucidation and the mechanism of the formation of these compounds are discussed.
Electron Spin Resonance Study on Photoinduced Changes of the Radicals Produced in Methyl Isocyanate Solid Irradiated with γ-Rays
Authors: Fujiwara Masato , Tamura Naoyuki , Hirai Hidefumi
Published: July 2006

Free radicals in the γ-irradiated solid of methyl isocyanate at −196°C have been studied by electron spin resonance (ESR) at −196∼−100°C. An oriented solid of methyl isocyanate was prepared by solidification of methyl isocyanate around an aluminum rod under cooling. The original radical and trapped electron produced by γ-irradiation were recorded at −196°C in the dark. The original radical produced in the oriented solid gave a resonance pattern consisting of a triplet of triplets and was assigned to ·CH2NCO radical. This was converted completely into a new radical on irradiation with visible light for 90 min. The new resonance pattern consists of a triplet of triplets whose nitrogen and proton splitting constants are 20.0 and 87.4 gauss, respectively. The nitrogen hyperfine splitting was anisotropic and the proton splitting constant agreed with that of methylene imino radical (H2C=N·). The new radical was assigned to methylene imino radical. The resonance pattern of ·CH2-NCO radical was restored when the temperature was raised up to −120°C. The mutual conversion between the two radicals by visible light and heat was concluded to be a decomposition of ·CH2NCO into H2C=N· and CO, and a recombination of these two moieties.
Automatic Recording of Liquid Penetration through Filter Paper and Wetting Behavior of Liquids
Authors: Nakamura Akio , Seimiya Tsutomu , Sasaki Tsunetaka
Published: July 2006

The penetration of liquid through a vertically suspended filter paper was studied by measuring the weight increase with a strain gauge tensiometer for several organic liquids and aqueous solutions. The plot of penetration rate K=h⁄t1⁄2 (h, height of liquid rise and t, time) against (σ⁄η)1⁄2 (σ, surface tension and η, viscosity coefficient of wetting liquids) showed two straight lines, one for organic liquids and the other for aqueous solutions of sodium dodecyl sulfate. Both these lines passed the origin, suggesting Lucas-Washburn formula to hold. The plots for ethyl alcohol-water mixtures showed behaviors intermediate between those two linear relations. The aqueous solutions caused swelling of fibers and reduced the mean capillary radius of the filter paper, resulting in a decrease of the penetration constant P=K⁄(σ⁄η)1⁄2 but with a rather large K value. The plots for penetration of water through an untreated paper fell far below the straight line obtained for aqueous solutions of sodium dodecyl sulfate. The penetration was recovered by removing fatty contaminants from the filter paper using Soxhlet extractor with ether. The results of a simple test of unfolding a folded paper by touching it with liquids are also in line with those mentioned above.
The Effects of Ion-pair Formation on the ESR Spectra of the Anion Radicals of 4-Nitropyridine N-Oxide and 4-Nitropyridine
Authors: Kawamura (née \={O}ishi) Yoshiko , Nishikida Koichi , Kubota Tanekazu
Published: July 2006

The effect of potassium ion-pair formation on the ESR spectra of the anion radicals of 4-nitropyridine and its N-oxide (4NPO) was studied at various temperatures lower than room temperature. The hyperfine splitting constant values due to hydrogen, nitrogen, and potassium nuclei were determined by applying the simulation technique. The above value arising from the potassium nucleus, decreased with a decrease in the temperature. Molecular orbital calculations covering the whole system of the 4NPO−–M+ ion pair and employing the McLachlan modification for the spin-density calculation were carried out in order to discuss the configuration of the ion pairs and the temperature dependence of the hyperfine coupling constants. It was reasonably concluded that an alkali metal cation occupies the C2 axis of the anion radicals and is in contact with the nitro-group oxygen atoms (the symmetry of the ion pairs is C2v.). The temperature dependence of the hyperfine splitting constants was explained using the vibrational model of Atherton and Weissman.