bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electronic Structures of Aromatic Ketyl Radicals and Related Hydrocarbon Radicals
Authors: Kanamaru Nobuaki , Nagakura Saburo 
Published: July 2006

Abstract
The π-electron structures of neutral aromatic ketyl radicals and their related hydrocarbon radicals were studied theoretically by combining the open-shell SCF MO method with the configuration-interaction calculation. The observed absorption bands of these radicals were well explained by the present theoretical study. From a comparison of the calculated transition energies and intensities with the observed values, it was concluded that the longest and second longest wavelength bands of the benzyl radical and the second longest wavelength band of the diphenylmethyl radical shift to shorter wavelengths upon hydroxy substitution. This may be regarded as characteristic of the substituent effect upon the absorption bands of aromatic radicals. The calculated spin densities were found to be consistent with the reactivity of the ketyl radicals in the formation of pinacols.
Studies of Acenaphthene Derivatives. XX. The Reactions of Benzylideneacenaphthenones with Sulfonium Ylides
Authors: Tsuge Otohiko , Shinkai Ichiro 
Published: July 2006

Abstract
The reactions of benzylideneacenaphthenones with sulfonium ylides were studied extensively. Although the reactions of benzylidene- and p-methylbenzylideneacenaphthenone with dimethylsulfonium methylide gave only resinous materials, the p-chlorobenzylidene derivative condensed with the ylide to afford the corresponding spiroxirane compound in a good yield. In the reactions with dimethyloxosulfonium methylide and carbonyl-stabilized sulfonium ylides such as ethyl (dimethylsulfuranilidene) acetate and dimethylsulfonium phenacylide, benzylidene-acenaphthenones gave the corresponding spirocyclopropyl ketones in good yields. The products obtained in the latter reactions were established to be cis-cyclopropyl compounds on the basis of NMR spectral studies. On the other hand, ethoxycarbonylmethyleneacenaphthenone condensed with carbonyl-stabilized sulfonium ylides to give trans-cyclopropyl ketones. On the basis of these results, the reaction mechanism was discussed. Also, bis-2,2′-methyleneacenaphthenone reacted with ethyl (dimethylsulfuranilidene) acetate to give the bis-spirocyclopropyl ketone.
The Preparation, Lithium Aluminum Hydride Reduction, and Electronic Spectra of Halogen-substituted 3,4-Bis(diphenylmethylene)-cyclobutenes and -cyclobutanes
Authors: Toda Fumio , Kumada Kunihiro , Ishiguro Nobuo , Akagi Katsuhiko 
Published: July 2006

Abstract
The title compounds were prepared, and their physical and chemical properties were investigated. The reduction of the cyclobutenes with lithium aluminum hydride afforded halogenfree cyclobutane. The mechanism of the reduction is discussed. The cyclobutenes showed their K-bands in a wavelength region ca. 100 nm shorter than in the cases of the corresponding cyclobutanes. Furthermore, the K-band of the cyclobutenes is comparable to that of 1-phenylbuta-1,3-diene. On the basis of the electronic spectral data, a puckered structure was postulated for the cyclobutenes.
Linear Conjugated Systems Bearing Aromatic Terminal Groups. II. The Synthesis and the Electronic Spectra of 9,9′ -Dianthrylpoly-ynes
Authors: Akiyama Shuzo , Nakagawa Masazumi 
Published: July 2006

Abstract
A series of 9,9′-dianthrylpoly-ynes (II1–II6) were prepared, and their electronic spectra were measured. It was found that the novel linear relation between λmax and the square of the number of the triple bond (n2) which has been found in the spectra of 1,1′-dianthrylpoly-ynes (I1–I6) also held in the 9,9′-series.
Aminocyclitols. XXIV. Synthesis of Inosamines from Bromodeoxyinositols
Authors: Suami Tetsuo , Ogawa Seiichiro , Uchida Masaru 
Published: July 2006

Abstract
Seven inosamines (scyllo, chiro-1, myo-2, myo-4, allo-5, neo-1 and chiro-3) have been prepared from four bromodeoxyinositols [scyllo, chiro-1, allo-5 and neo-1). When bromodeoxyinositols were treated with sodium azide in boiling aqueous 2-methoxyethanol or dimethylformamide, followed by acetylation, pentaacetyl azidodeoxyinositols were obtained in 60–80% yield. On catalytic hydrogenation using Adams’ platinum oxide, the azido compounds yielded hexaacetyl inosamines in good yields. Proton magnetic resonance (PMR) spectra of acetyl azidodeoxyinositols have been studied.
The Effect of Solvents on the Optical Rotation of Poly(propylene Oxide)
Authors: Kumata Yoshiyuki , Furukawa Junji , Fueno Takayuki 
Published: July 2006

Abstract
The change in the rotatory direction of optically active poly(propylene oxide) in different solvents has been discussed from the viewpoint of dielectric theory of solution. It has been pointed out that, in general, the shapes of the optical rotatory dispersion curves of polymers cannot directly be related to their conformation.
The Phase Transitions of the Anion Radical Salts Containing Mixed Cations; [(C6H5)3PCH3]1−x+[(C6H5)3AsCH3]x+(TCNQ)2\ewdot, (0≤x≤1)
Authors: Iida Yôichi 
Published: July 2006

Abstract
The phase transitions of the anion radical salts containing mixed cations represented by [(C6H5)3PCH3]1−x+[(C6H5)3AsCH3]x+(TCNQ)2\ewdot, (0≤x≤1) were investigated. The transition temperature, Tc, and the magnitude of the heat, ΔH, of the transition were determined as a function of the composition parameter, x, by means of a differential scanning calorimeter. It was found that Tc increases, and ΔH decreases, monotonously with an increase in the value of x, and that the phase transition disappears with x=1.00. The mechanism of the phase transitions was discussed on the basis of the theory of triplet exciton-exciton interaction proposed by Chesnut. The theoretical values of the entropy changes of the transitions were found to be much less than those observed. In view of these results, it was concluded that the anomalies in the magnetic susceptibilities of these salts were induced by the change in the crystal structure.
Phosphorus Nuclear Magnetic Resonance in Polyphosphates and Determination of Their Hydrolysis Rate Constants
Authors: Kawabe Makoto , Ohashi Osamu , Yamaguchi Ichiro 
Published: July 2006

Abstract
The phosphorus nuclear magnetic resonance spectra of several condensed phosphates (polyphosphates) were measured in aqueous solutions. The NMR spectra generally consist of three peaks which correspond to the phosphorus atoms at the end and middle of the molecular chain and in orthophosphoric acid which is the final product of the hydrolysis. The chemical shift and, for some phosphates, spin-spin coupling constants were obtained. Both depend on pH of the solution. The chemical shifts for the end and middle phosphorus atoms depend also on the chain length of the molecule. The hydrolysis process of the phosphates can be traced by the observation of the time dependence of spectral line intensities. From this observation the rate constant of the hydrolysis is obtained for several phosphates. The values are comparable with those obtained by other methods.
An Infrared Spectroscopic Study of Hydrogen Bonding Interaction. Structural Studies of Proton-donating and -accepting Powers
Authors: Kagiya Tsutomu , Sumida Yūzō , Tachi Toshihiro 
Published: July 2006

Abstract
The relationship between the proton-donating and proton-accepting powers and the structures of various proton donors and acceptors was studied in the liquid phase by means of an infrared spectrophotometer. The proton-donating powers of the donors were evaluated by means of the ratios of the O–H shifts of the donors (RO–H) to those of methanol in various proton acceptor solutions. The proton-accepting powers of the acceptors were evaluated by means of the division of the O–H shifts by the proton-donating powers of the donors used. The proton-donating powers increased with the decrease in the pKa or the ionic RO–H bond dissociation energies and with the increase in the electron affinities of RO radicals, i. e., t-butanol&lt;methanol&lt;&lt;trimethylsilanol&lt;phenol&lt;p-nitrophenol. In a homologous series, the proton-accepting powers increased with the decrease in the ionization potentials. In the case of the aromatic ethers with two proton accepting sites, two characteristic O–H vibrational bands were observed. The difference in the protonaccepting powers of the vinyl and ethyl compounds with the same substituent was observed, and the π-electron-mobility index, which was considered to be a measure of the energy level of the π-electrons of the vinyl group, was defined and discussed.
An ESR Study of Intermediates in γ-Irradiated Methylcyclohexane and Isobutane Containing Benzene
Authors: Wakayama Terunobu , Miyazaki Tetsuo , Fueki Kenji , Kuri Zen-ichiro 
Published: July 2006

Abstract
The present work was undertaken in order to examine intermediates from benzene and toluene in γ-irradiated glassy methylcyclohexane (MCH) and polycrystalline isobutane matrices at 77°K. The γ-irradiation of MCH containing low concentrations of benzene gave an ESR spectrum with a good hyperflne resolution, which can be ascribed to the benzene anion, while at higher concentrations of benzene it gave an ESR spectrum with a poor resolution, which is attributable to the benzene monomer and dimer anions. On the contrary, the γ-irradiation of polycrystalline isobutane containing benzene did not yield an ESR spectrum which can be attributed to the benzene anion. However, the γ-irradiation of a mixed glass of isobutane and 4 mol% MCH containing benzene gave an ESR spectrum which is attributable to the benzene anion. The yield of trapped electrons in this system was three times as large as that in pure γ-irradiated MCH. Such a difference in the results between glassy MCH and polycrystalline isobutane matrices gives evidence of a phase effect on the radiolysis of solid hydrocarbon.
Electron Spin-Spin Interaction and Methylene Bond Angles in the Quintet Ground State of m-Phenylene-dimethylene Radicals
Authors: Higuchi Jiro 
Published: July 2006

Abstract
The effect of the methylene bond angles on the electron spin-spin interaction has been semiempirically investigated for the quintet ground states of the m-phenylene-dimethylene radicals, especially m-phenylene-bismethylene and m-phenylene-bisphenylmethylene. The D and E values calculated are compared with those observed, and the most probable structure, with a methylene bond angle near 140°, is estimated, as in the phenylmethylene radical.
The Chemical Modification of Biopolymers. III. The Introduction of SH Groups into Taka-amylase A
Authors: Suzuki Shuichi , Hachimori Yutaka , Matoba Ryuichi 
Published: July 2006

Abstract
The enzymic activity of Taka-amylase A on amylose, as measured by the blue-value method, increased to 180% of the original when one mole of mercaptosuccinyl group was introduced into one mole of the enzyme. Similar results were obtained for the activity measured by the Semogyi-Nelson method; the introduction of one or two mercaptosuccinyl groups raised the activity to 130–140% of that of the native enzyme. Even after the attachment of six mercaptosuccinyl groups per mole, the activity was 120% of the original. However, the enzymic activity was not elevated, but was lowered, by succinylation. When the sulfhydryl groups of the mercaptosuccinyl groups were blocked with p-chloromercurybenzoate or iodoacetamide, the enzyme was inhibited. These results suggest that the sulfhydryl groups of mercaptosuccinyl residues play an important role in increasing the enzymic activity.
Polyamino-Zucker. VI. Synthese von Derivaten der 2,3,4-Triamino-2,3,4-tridesoxy-β-d-glucose
Authors: Nakagawa Toshio , Sato Yoshikuni , Takamoto Tetsuyoshi , W. Lichtenthaler Frieder , Majer Norbert 
Published: July 2006

Abstract
A facile synthesis of methyl and phenyl glycoside derivatives of 2,3,4-triamino-2,3,4-trideoxy-β-d-glucopyranose is described, involving as the integral part the diamination with benzylamine or ammonia of 2,4,6-tri-O-acetyl-3-deoxy-3-nitro-hexosides of gluco- and galacto-configuration.
Preparation of Chromium(III) and Cobalt(III) Complexes with l-Leucine-N,N-diacetic Acid
Authors: Uehara Akira , Kyuno Eishin , Tsuchiya Ryokichi 
Published: July 2006

Abstract
l-Leucine-N,N-diacetic acid (abbreviated as LDA) and the complexes thereof were prepared as follows: K[Cr(OH)(lda)(H2O)]·3H2O (violet) (I), [Cr(lda)(H2O)2] (bluish violet) (II), [Cr(lda)(H2O)2]·2H2O (grayish violet) (III), (enH2)1⁄2[Cr(OH)(lda)(H2O)2] (green) (IV), [Cr(lda)(o-phen)]·2H20 (brownish orange) (V), K[Cr(lda)(acac)]·H2O (blackish violet) (VI) and K[Co(OH)(lda)(H20)]·H2O (bluish violet) (VII), where lda, en, o-phen and acac are the abbreviations of l-leucine-N,N-diacetate ion, ethylenediamine, o-phenanthroline and acetylaceto-nate ion, respectively. Except for Complex IV, LDA behaves as a quadridentate ligand. In Complex IV, it acts as a terdentate one. It was found from electronic absorption spectra that in Complex I, LDA behaves as a quadridentate in a solid state and as a terdentate ligand in an aqueous solution, whereas in cobalt(III) complex VII corresponding to I, LDA behaves as a quadridentate. Stepwise liberation of the coordinated water molecules in Complexes II and III could be detected by means of Derivatograph. Complex VII showed “Dehydration-Dimerization Reaction” upon being heated.
Alkoxysilanes. IV. Preparation of Alkoxysiloxy Derivatives of Titanium
Authors: Abe Yoshimoto , Kijima Ichiro 
Published: July 2006

Abstract
Alkoxysiloxy derivatives of titanium and polymeric substances with Ti–O–Si bonds were prepared. The reaction of titanium tetra-isopropoxide or bis (acetylacetonato)di-isopropoxytitanium with tri-t-butoxysilanol led to the formation of the derivatives of [(ButO)3SiO]nTi(OPri)4−n (n=2 and 3) and those of [(ButO)3SiO]2Ti(AcAc)2 respectively. In both of these series, the absorption peak of the Ti–O–Si bond in the IR spectrum shifted toward a lower wave number from the compounds of n=2 to those of n=3. The reaction of titanium tetra-isopropoxide with di-t-butoxysilanediol, as expected, gave a polymeric substance. In the reaction with bis(tri-t-butoxysiloxy)-silanediol, however, an unexpected cyclic compound consisting of the Ti–O–Si bond was obtained; its presence was confirmed by a study of the IR and NMR spectra, by elemental analysis, and by molecular-weight determination. In order to obtain a linear polymer, the reaction of the titanium acetylacetonato chelate with the silanediols was carried out to give a reddish-brown, highly viscous liquid or solid. These polymeric substances were soluble in common organic solvents and have an appreciable hydrolytic stability, but only a moderate thermal stability.
Anomalous Products Obtained by Nitration of Pentamethylbenzene, Pentaethylbenzene, and Some Mixed Penta-alkylbenzenes
Authors: Suzuki Hitomi , Nakamura Kiyomi 
Published: July 2006

Abstract
Pentamethylbenzene has been nitrated with fuming nitric acid to give mainly a mixture of nitropentamethylbenzene and 2,3,4,5-tetramethylbenzyl nitrate. Other isomeric nitrates were not formed in any significant amount. 6-Nitro-2,3,4,5-tetramethylbenzyl nitrate, 2,3,4,5-tetramethylbenzyl alcohol, 2,3,4,5-tetramethylbenzaldehyde, 2,2′,3,3′,4,4′,5,5′,6-nonamethyldiphenylmethane, and 2,2′,3,3′,4,4′,5,5′-octamethyl-6-nitroxymethyldiphenylmethane were the minor products. Pentaethylbenzene gave a mixture of nitropentaethylbenzene and α-methyl-2,3,4,5-tetraethylbenzyl nitrate along with some products of oxidation. Preferential side-chain attack occurred at the primary alkyl group ortho to the unsubstituted ring position. Thus, 1-methyl-2,3,4,5-tetraethylbenzene was found to give benzyl nitrate and α-methylbenzyl nitrate nearly in equal amounts, while 3-methyl-1,2,4,5-tetraethylbenzene was found to give them in an approximate ratio of 1 : 3. 1,3,4-Trimethyl-2,5-diisopropylbenzene underwent extensive nitrodealkylation, and 3,4-dimethyl-2,5-diisopropylbenzyl nitrate was the only side-chain substituted product identified.
Orientation of the Products from the Nitration of Halopentamethylbenzenes
Authors: Suzuki Hitomi 
Published: July 2006

Abstract
The action of fuming nitric acid upon chloropentamethylbenzene, bromopentamethylbenzene, and iodopentamethylbenzene has been investigated. 5-Halo-2,3,4,6-tetramethyl- and 6-halo-2,3,4,5-tetramethylbenzyl nitrate were the principal products. 4-Halo-2,3,5,6-tetramethylbenzyl nitrate was never formed in any significant amount. The orientation was consistent with the previously suggested mechanistic scheme. PMR spectral data for nine halotetramethylbenzyl chlorides and nitrates have been presented.
The Non-enzymatic Cleavage of Peptide Bonds. II. The Chemical Cleavage of the Tryptophyl Bond in Several Synthetic Peptides
Authors: Morishita Michiyo , Sakiyama Fumio 
Published: July 2006

Abstract
Several synthetic peptide derivatives containing tryptophan were examined for the selective cleavage at the tryptophyl residue, according to a new scheme involving ozonization and subsequent treatment with hydrazine. The ozonization reaction of the tryptophyl residue was carried out in the presence and in the absence of resorcinol in formic acid. Then the reaction of the ozonized product with hydrazine was performed at pH 3.6 to bring about the tryptophyl bond cleavage. The yield of the present cleavage reaction ranged from 35 to 68% on the basis of the starting peptide derivative used. The cleavage reaction could be followed spectroscopically in parallel with the exposure of the amino group acylated by the tryptophyl residue. The 2,3,4,5-tetrahydropyridazone derivative derived from the parental tryptophyl residue was identified by a comparison of both its chromato-graphic behavior and its ultraviolet spectrum with those of the standard sample. Thus it was confirmed that the present cleavage proceeded through the proposed reaction sequence.
Theory of Solvent Effects on Oscillator Strengths for Molecular Electronic Transitions
Authors: Abe Takehiro 
Published: July 2006

Abstract
A theoretical expression has been presented for an oscillator strength of an electronic transition in a solute molecule immersed in an isotropic dielectric continuum of solvent. It is assumed that a charged particle in the solute is subjected to a force due to a cavity field. The approximate expression derived on the basis of a quantum-mechanical perturbation theory has been successfully tested for nitrobenzene and acetone.
Measurement of the Hydrogen Ion Concentration in the Vicinity of the Anode during Electrodeposition of Water-Soluble Resin
Authors: Nakamura Yoshio , Komata Kimio , Nozaki Hiroshi 
Published: July 2006

Abstract
In order to make clear the mechanism of the electrodeposition of water-soluble resin, the hydrogen ion concentration in the vicinity of the anode during electrodeposition was measured using a quinhydrone reaction on platinum wire. The measured concentration of hydrogen ions in the vicinity of the anode was then compared with that of hydrogen ions which had been calculated according to the diffusion theory. The results show that the most of the hydrogen ions produced at the anode during electodeposition are consumed in the vicinity of the anode. This shows that there is apparently ionic combination of hydrogen ions with organic anions on the anode; this may lead to the deposition of organic anions.
Semi-empirical Unrestricted SCF-MO Treatment for Valence Electron Systems. II. The Angular Dependence of the Methyl Group hfs Constants
Authors: Nakatsuji Hiroshi , Kato Hiroshi , Yonezawa Teijiro 
Published: July 2006

Abstract
Since the spin-polarization contribution to the methyl-group hfs constant of the ethyl radical has been recognized to be important, the angular dependence of the β-proton hfs constants is re-examined for various radicals. Thus, the observed relation, Q(θ)=B0+B1cos2θ, is interpreted as being the sum of the following two equations.
& Q_SD(θ)=(B_1)_SDcos^2θ
& Q_sp(θ)=(B_0)_SP+(B_1)_SPcos^2θ,
where SD and SP denote the spin delocalization and spin polarization contributions respectively. θ is the rotational angle about C–C single bond. A molecular orbital description of the above angular dependences is also given.
Charge-Transfer Complexes of Maleic Anhydride and Dichloromaleic Anhydride with Various Aromatic Compounds
Authors: Kobayashi Takayoshi , Iwata Suehiro , Nagakura Saburo 
Published: July 2006

Abstract
Absorption, fluorescence and fluorescence excitation spectra were measured at room temperature and at low temperature for charge-transfer complexes containing maleic anhydride and dichloromaleic anhydride as electron acceptors. Benzene, toluene, mesitylene, durene, hexamethylbenzene, aniline, dimethylaniline, naphthalene and anthracene were used as electron donors. The charge-transfer absorption and fluorescence bands were observed for these complexes, their peak positions being linearly dependent upon the ionization potentials of donors for the same electron acceptor. From the comparison of the charge-transfer absorption or fluorescence peaks of maleic anhydride complexes with the corresponding values of dichloromaleic anhydride complexes, the difference in electron affinity between these two electron acceptors was obtained to be 0.4 eV. The electronic structures of the maleic anhydride complexes with benzene, naphthalene and anthracene were studied theoretically by considering the configuration interaction among the ground, locally-excited and charge-transfer configurations. The stable geometrical configurations in the ground and lower excited states of the complexes were discussed by the aid of the energy levels calculated for various relative orientations between electron donor and acceptor.
Stability of Tropolone Chelates of the Bi- and Tervalent Metal Ions
Authors: Hirai Michio , Oka Yoshinaga 
Published: July 2006

Abstract
The reaction of tropolone with several bi- and tervalent metal ions has been studied spectrophotometrically. Their stability constants (k1) have been found to be 7.40, 3.82, 3.06, 2.45, 7.46, 4.60, and 6.25 for Be(II), Mg(II), Ca(II), Sr(II), Y(III), Cd(II), and La(III) respectively, at 25±0.1°C and at an ionic strength of 0.10. A plot of logk1 against e2⁄r gave a straight line for all the non-polarizable metal ions except Be(II) and Mg(II). The logk1 values for all the polarizable metal ions are large. The correlation of logk1 with the second or the third ionization potentials for bi- and tervalent metal ions gave a fairly straight line.
Nitroalkenylferrocene. V. New Reactions of α-Halonitroolefins in the Presence of Sodium Alkoxides
Authors: Shiga Mikio , Tsunashima Masaaki , Kono Hiromichi , Motoyama Izumi , Hata Kazuo 
Published: July 2006

Abstract
The reactions of 1-iodo-2-ferrocenyl-1-nitroethylene (1) and β-bromo-β-nitrostyrene (5) with various sodium alkoxides were investigated. The reaction in the presence of an excess of alkoxides gave nitroketones, (2) and (6), and nitroacetals (3) and (7). The thermal decomposition of the nitroacetals in a nitrogen atmosphere afforded β-alkoxynitroolefins (8), which were found to be useful for obtaining asymmetric nitroacetals (9) with different alkoxy groups. The reaction mechanism was discussed by postulating the intervention of a nitrocarbene (12) and β-alkoxynitroolefin (8). The intermediacy of the nitrocarbene was supported by an experiment using vinylferrocene as a carbene scavenger.
Reactions of Nitrones with Free Radicals. II. Formation of Nitroxides
Authors: Iwamura Michiko , Inamoto Naoki 
Published: July 2006

Abstract
Reactions of N-t-butylaldonitrones with free radicals gave stable nitroxides, one of which was isolated in pure state. The stability of the nitroxides was explained by the steric effect around the nitrogen and α-carbon atoms. In the reaction of 5,5-dimethyl-Δ1-pyrroline N-oxide with AIBN, nitroxide was detected by ESR technique, and 1,3-adduct and ketonitrone were isolated from the reaction mixture. From the results, it was confirmed that nitroxide is the intermediate of the 1,3-adduct formation and that a radical first adds to the carbon atom and then adds to the oxygen atom of the nitrones.