bluuebunny/crossref_metadata_2025 huggingface dataset:
Electronic States of Diphenylamine and Its Related Compounds
Authors: Hinohara Tadao , Cho Seikichi , Morita Toshifumi
Published: July 2006

For the analysis of the characteristic nature of the first absorption band of diphenylamine (DPA), calculations of the electronic states of DPA and its analogous compounds, diphenylether (DPE) and diphenylmethane (DPM), were carried out and the solvent effects on the fluorescence spectra of these compounds were investigated. The calculated results show that the first excited states of these three compounds are mainly benzene B2u. However, in DPA, the ionic state (CTs−) is located very closely to the B2u state. It seems reasonable to say, therefore, that, in solution, the ionic state lowers its energy down to the position of the B2u state and that the first absorption band observed in the solution is a superposed band of two transitions, G→B2u and G→CTs−. To confirm this assumption, the value of Δμ, which is the dipole-moment change between the ground and excited states, is estimated from the solvent effect on the fluorescence spectrum. The observed value of Δμ for DPA is intermediate between the theoretical values for the lowest (B2u) and the second excited state (CTs−) ; from this fact it may be inferred that the mixing of CTs− to the lowest excited state (B2u) is increased in the excited equilibrium state.
Studies on Salt Solution Aerosols. IV. Droplet Size Determination of Aqueous Sodium Chloride Solution Aerosols by Chemical Spot Method
Authors: Ueno Yasuo , Sano Isamu
Published: July 2006

Droplets of aqueous NaCl solution aerosols generated by atomization were collected on an AgNO3 containing film, by measuring microscopically the sizes of the AgCl spots formed on the film, the diameters of the droplets were determined with the aid of the calibration curve between the spot and droplet diameters. It was found that the calibration curve can be expressed by a relation Dd3=Kds2, where Dd is the volume average diameter of the droplets, ds the surface average diameter of the spots and K a constant. The meaning of K was considered.
Photosensitive Ionomer. I. Preparation of Mercurous Acrylate and Photosensitive Plates
Authors: Suzuki Shin , Sugita Kazuyuki
Published: July 2006

Photographic plates were prepared by coating an emulsion consisting of mercurous acrylate, polyvinyl alcohol and water on glass plates. They were found to be sensitive to light ranging from 250 nm to 340 nm. A dark brown image with density ca. 0.6 above the fog was formed by a printing-out process. The latent image could be amplified with the reducing developers such as hydroquinone or metol. Image formation was ascribed to metallic mercury which was isolated by photoreduction and/or reduction of mercurous ion.
Intermolecular Forces and Rotational Phase Transition in the C2H2 Crystal
Authors: Hashimoto Masao , Hashimoto Michiko , Isobe Taro
Published: July 2006

The potential energy of the acetylene crystal was calculated as a function of the rotational molecular orientations. The potential energy of this crystal has two kinds of minima, not a double minima; one arises from the quadrupole-quadrupole interaction, to which the high-temperature is due, while the other arises from the overlap repulsion interaction with which the low temperature structure is coincident. It was suggested that the mechanism of the phase transition in this crystal is a rotational transition between the two molecular orientations.
The Crystal and Molecular Structure of π-Cyclooctenyl-π-cycloocta-1,5-dienecobalt, Co(C8H13) (C8H12)
Authors: Koda Shigetaka , Takenaka Akio , Watanabé Tokunosuké
Published: July 2006

The crystal structure of π-cyclooctenyl-π-cycloocta-1,5-dienecobalt, Co(C8H13)(C8H12), has been established by successive Fourier analyses. The atomic parameters were refined by least-squares techniques using three-dimensional X-ray data to an R factor of 0.125. The complex molecule crystallizes in the space group P21⁄c with four molecules in the unit cell of dimensions: a=10.78, b=7.30, c=17.81 Å, β=104.2°. The four cobalt atoms lie nearly on the face-centered positions in the unit cell and are sandwiched between the two ligands, cyclooctenyl C8H13 and cyclooctadiene C8H12. The seven nearest Co···C distances range from 2.02 Å to 2.09 Å. Atoms Co, C(1), C(3) and the respective centers of the two double bonds, C(9)–C(16) and C(12)–C(13), in C8H12 ring are coplanar to within 0.08 Å. The conformation of C8H13 is of the tub form and C8H12 of the boat form. The two lengths of the double bonds in C8H12 are 1.41 Å and 1.39 Å, while those in the allyl part in C8H13 are 1.35 Å and 1.46 Å, respectively. The average distance of the remaining twelve C–C bonds is 1.54 Å.
The Primary Process of the Photochemical Dimerization of Carbostyril
Authors: Yamamuro Tetsu , Tanaka Ikuzo , Hata Norisuke
Published: July 2006

Carbostyril dimerizes photochemically in ethanol to yield its dimer. In order to clarify the primary process of this photochemical dimerization, studies by means of steady-light irradiation and flash spectroscopy and measurements of the absorption spectrum of the intermediate and of the phosphorescence spectrum at 77°K were carried out under various conditions. The transient absorption was observed around 430 mμ, it was identified as being due to a T–T transition of carbostyril. Experiments on both the decay kinetics of the triplet species and the quantum yield of the carbostyril disappearance under various conditions revealed that the photochemical dimerization of carbostyril proceeded through a bimolecular interaction between the triplet and the unexcited molecules.
Absorption Spectra of Crystals of Cytosine and Its Derivatives
Authors: Tanaka Masashi , Tanaka Jiro
Published: July 2006

The electronic spectra of cytosine, one of DNA bases, have been studied. The absorption spectra of single crystals of cytosine and its derivatives are presented, and the direction of the transition moment of the first π→π* band is determined to be inclined at about +100° from the N1–C4 line toward the C5 atom. The second π→π* band is shown to have polarization direction at +30° inclined to the reference axis.
Spreadability of Ovalbumin Monolayers at Air-water Interface. Effects of Additives to Spreading Solutions
Authors: Ishii Toshio , Muramatsu Mitsuo
Published: July 2006

The effect of additives (urea, potassium chloride, butanol, and thioglycol) to spreading solutions upon spread-ability of ovalbumin monolayers has been studied in terms of the rate constants and the limiting areas for intermediate (fast) and final (slow) processes of uncoiling of the protein molecule. It has been found that the addition results in the disappearance of the first (fast) process, which appeared upon spreading without additives. In the second (slow) process, the rate constant is found to be the same as that for the case without additives regardless of the type of the additives. Sodium dodecyl sulfate (SDS) added to the spreading solution is showed a peculiar behavior, which is explained in relation to the interaction between the protein and SDS molecules.
Electronic Structures, Electronic Spectra, and Aromatic Characteristics of Peri-Condensed Tetracyclic Nonbenzenoid Aromatic Hydrocarbons Containing a Naphthalene Nucleus
Authors: Yamaguchi Hiroyuki , Nakajima Takeshi
Published: July 2006

The ground-state electronic properties and electronic spectra of pyracylene (I), acepleiadylene (II), and dipleiadiene (III) have been studied by using the semi-empirical SCF LCAO-π-MO method, which allows for bond order-bond length correlation at each iteration. It is shown that the I and III molecules do not belong to, respectively, the pentalenoid and heptalenoid systems, as was expected from the HMO energy diagram. The predicted chemical reactivities, diamagnetic anisotropics, and electronic spectra for I and II are in good agreement with the available experimental data. The calculated C–C bond lengths indicate that the I, II, and III molecules are all both aromatic and polyolefinic. The upfield shift of the NMR spectrum and the unusually low value of the first half-wave potential for I can be well explained in terms of, respectively, the diamagnetic anisotropy and the energy of the lowest vacant SCF MO, calculated by using the predicted equilibrium configuration that corresponds to the aromatic model (Ia).
Studies of Organic Peroxides. XI. The Reaction of Benzoyl Peroxide with Secondary Amines in Binary Mixed Solvents
Authors: Hasegawa Shigeo , Kashino Setsuo , Mukahi Yoshinobu
Published: July 2006

The rate constants of the reaction of benzoyl peroxide with some typical secondary amines, namely, diphenylamine, N-methylaniline, and piperidine, were measured in benzene-nitrobenzene binary mixed solvents. The reaction rates of diphenylamine and N-methylaniline are little influenced by the compositions of the solvents, while the reaction of piperidine proceeds more rapidly in nitrobenzene than in benzene. The isokinetic relationship holds for the reaction of piperidine in the binary mixed solvents. The isokinetic temperature is calculated to be 265°K. The analysis of the behavior of these reactions in the mixed solvents leads to the conclusion that, in the cases of diphenylamine and N-methylaniline, there are no specific interactions between the activated complexes and solvent molecules, whereas in the case of piperidine the activated complex is weakly solvated with the polar nitrobenzene. The reaction of benzoyl peroxide with N-methylaniline and N-n-butylaniline was also studied in benzene. These amines have a higher reactivity than would be expected from their basicity. This higher reactivity is probably due to the resonance stabilization of the activated complex besides the formation of a lessionic activated complex.
A Polarographic Study of the Complex Formation Equilibria of the Lead(II) Ion with Aspartic and Iminodiacetic Acids
Authors: Kodama Mutsuo , Takahashi Sozo
Published: July 2006

In this experiment, we studied the complex formation equilibria of the lead(II) ion with aspartic acid and iminodiacetic acid by using the polarographic method. In acetate buffer solutions (5.80>pH>3.70), the lead(II) ion forms one normal complex, PbX0, and two mixed ligand complexes involving the acetate ion, PbX(Ac)−and PbX(Ac)22−, with aspartic acid. On the other hand, with iminodiacetic acid, it forms a normal complex, PbX0, and only one mixed ligand complex, PbX(Ac)−. By observing the effects of the concentrations of the hydrogen ion, the acetate ion, and aspartic acid or iminodiacetic acid on the half-wave potential of the lead(II) ion, their formation constants were determined to be as follows:

(Remark: Graphics omitted.)
Derivatographic Studies on Transition Metal Complexes. IV. Deaquation-Olation of Hydroxoaquo Cobalt(III) Complexes with Aminotricarboxylic Acids.
Authors: Tsuchiya Ryokichi , Uehara Akira , Kyuno Eishin
Published: July 2006

Thermochemical functions of the deaquation-olation on K[Co(OH)L4(H2O)] type complexes in the solid phase were determined by means of derivatography and UV spectral measurements and the mechanisms were discussed on the basis of the results. In the above formula, L4, denotes nitrilotriacetate (nta), nitriloisopropionicdiacetate (nipda), d,l-α-amino-n-butyric-N,N-diacetate (α-abda), l-leucine-N,N-diacetate (lda), l-valine-N,N-diacetate (vda), d-α-phenylglycine-N,N-diacetate (pgda), or d,l-α-phenylalanine-N,N-diacetate (pada) ions. These complexes were found to liberate one mole of coordinating water upon heating and to turn into the olated compound bridged with two OH groups at the same time. From an estimation of enthalpy change and activation energy for the reaction, it was found that the reaction is apt to take place more easily as the structural complexities of chelating agents increase and that the reaction always proceeds in the first order. We might conclude that the evolution of coordinating water is the rate-determining step in the reaction.
Derivatographic Studies on Transition Metal Complexes. V. Thermal cis, trans-to-trans, cis Isomerization of [CoCl2(NH3)2en]ClO4 in Solid Phase
Authors: Tsuchiya Ryokichi , Nakata Yasuo , Kyuno Eishin
Published: July 2006

The complex, cis,trans-[CoCl2(NH3)2en]ClO4, regardless whether its state is monohydrate or anhydride, was isomerized to trans,cis-form by heating in a solid phase. In the kinetic study on perchlorate in a closed system, it was found that the isomerization of the hydrated compound proceeded through a second order reaction with respect to the remaining fraction of the starting compound with the activation energy, E≠=29.5 kcal mol−1, while that of the anhydrous one proceeded through a first order reaction with E≠=51.4 kcal mol−1. On the other hand, derivatographic analyses showed that the enthalpy change in the dehydration partly including isomerization was ΔH=13.9 kcal mol−1 for the monohydrated perchlorate and the activation energy was E≠=39.9 kcal mol−1, whereas the enthalpy change of isomerization of the anhydrous perchlorate was ΔH=−2.1 kcal mol−1. From the results, it is believed that the “Aquation-anation” mechanism on the crystal surface is predominant in the isomerization for the hydrate, but it proceeds through some intramolecular reactions for the anhydride.
Synthesis of Iron-Titanium Oxides under Hydrothermal Conditions
Authors: Matsuoka Kiyoshi
Published: July 2006

The solid solutions in the system FeO-Fe2O3-TiO2 were synthesized under hydrothermal conditions up to 700°C and 2.5 kb (PH2O). The results of X-ray diffraction, chemical and thermomagnetic analyses indicated that the products always consisted of magnetite-ulvöspinel or hematite-ilmenite solid solutions and, in some cases, rutile was also formed. The presence of the solid solutions of magnetite and ulvöspinel indicates a reducing atmosphere during the treatment. When PH2O increased from 1 kb to 2.5 kb, the FeO contents in the products decreased.
119Sn-Mössbauer and 1H- and 55Mn-NMR Spectroscopic Studies of a Series of Compounds, R3−xXxSn-Mn(CO)5
Authors: Onaka Satoru , Sasaki Yukiyoshi , Sano Hirotoshi
Published: July 2006

The electronic configuration around the tin atom for a series of organotin-manganese compounds, R3−xXxSn–Mn(CO)5, has been studied by 119Sn-Mössbauer and 1H- and 55Mn-NMR spectroscopies. All the results obtained from these spectroscopic measurements show that the Mn(CO)5 group is a stronger electron donor than the methyl, phenyl, or halogen group and that the tin-manganese bond prefers the sσ-character whereas the tin-halogen bond prefers the pσ-character. The relationship between the 55Mn-chemical shift and the 119Sn-isomer shift indicates some σ-electron withdrawal from manganese to tin. The phenyl group reduces the magnitude of quadrupole splitting more than the methyl group; this fact may be due to the mesomeric effect of the phenyl group through the π-bond between tin and ligand atoms. The relationship among the 119Sn-isomer shift, the 1H-chemical shift, and the coupling constant J(119Sn-1H(CH3)) is also shown.
The Determination of Tin in Tin Metal and in Zircaloy by Precise Coulometric Titration
Authors: Yoshimori Takayoshi , Matsubara Ikuko , Tanaka Tatsuhiko , Yoshida Kazuo , Tanaka Kazuo , Tanabe Toyokazu
Published: July 2006

The purities of tin metals are determined directly by precise coulometric titration. The sample is dissolved with hydrochloric acid in a nitrogen atmosphere. The solution is then introduced into a hot antimony column. The reduced tin(II) ions are titrated with electrolytically-generated iodine. The titration is accomplished in a special cell by the use of which any disturbance of atmospheric oxygen is avoided. The titration efficiency under these acidic media was decreased when the current density was increased more than several mA/cm2. The results obtained by two different analysts for the sample of the pure tin metal (5-nine) were 99.996 and 99.991%. The standard deviations of the results were 0.025 and 0.016% respectively. The tin in the other tin metals and in Zircaloy samples was determined satisfactorily without the use of any experimental factor.
The Preparation and the Structure of (1,9-Diamino-1,4,6,6,9-pentamethyl-3,7-diazanona-3-ene) (l-propylenediamine)nickel(II) Perchlorate
Authors: Ito Haruko , Fujita Junnosuke
Published: July 2006

A new purple complex of (1,9-diamino-1,4,6,6,9-pentamethyl-3,7-diazanona-3-ene) (l-propylenediamine)nickel(II) perchlorate and the known yellow complex, (octamethyl-1,4,8,11-tetraazacyclotetradecadiene)nickel(II) perchlorate, were obtained by the reaction of tris(l-propylenediamine)nickel(II) perchlorate and acetone without any irradiation by ultraviolet light. The structure of the purple complex was estimated from its absorption and circular dichroism spectra in acetonitril and in an aqueous solution, and from its infrared spectrum in the solid state. The complex was found to take an octahedral [NiN6]-type structure in acetonitril and a planar [NiN4]-type structure in aqueous solution. The (1,9-diamino-1,4,6,6,9-pentamethyl-3,7-diazanona-3-ene)nickel(II) perchlorate and (1,9-diamino-1,4,6,6,9-pentamethyl-3,7-diazanona-3-ene)(ethylenediamine)nickel(II) perchlorate complexes were also prepared.
Studies of the Interaction between the Picrate Ion and Alkali Metal Ions
Authors: Yamane Mitsuo , Iwachido Tadashi , Tôei Kyoji
Published: July 2006

Alkali metal picrates in an aqueous solution are extractable by nitrobenzene. The investigations of the equilibria in and between the aqueous and organic phases show that the larger the association constants in the aqueous phase and the dissociation constants in the organic phase, the greater the extractability of the salts. The extremely low extractability of alkali metal picrates can be well explained in terms of such equilibrium constants.
A Study of the Catalytic Partial Oxidation of Hydrocarbons. VI. The Effect of Molybdenum Addition to the Vanadium Oxide Catalyst on the Oxidation of Butene to Maleic Anhydride
Authors: Ai Mamoru
Published: July 2006

In the present work, the vapor-phase partial oxidation of cis-2-butene was carried out using V2O5-MoO3 catalysts with different compositions, at 350°C, and at a butene content of 0.65% in air, in order to elucidate the effect of the addition of MoO3 to the V2O5 catalyst on the selectivity and the mechanism for maleic anhydride formation. Two types of catalytic specificities were found, depending upon the Mo content: in the range of less than 20 atom% Mo, the specificity was similar to that of V2O5 alone, while in the range of more than 50 atom% Mo, a different specificity was observed, one which gave 1.2 times the yield of maleic anhydride than did V2O5 alone or the Mo-poor catalysts. The increase in the selectivity of butene to maleic anhydride which occurred when a large amount of MoO3 was doped is considered to be caused by the increase in the selectivity of the C4H4O→MA step, not in that of the C4H8→C4H6 or C4H6→C4H4O step. The selectivity of the side pathway in the C4H8→C4H6step was so great that no satisfactory maleic anhydride yield from butene can be expected by the use of the V2O5-MoO3 catalyst.
Effective Intramolecular Hydrogen Abstraction by the Sulfonamide Radical
Authors: Ohashi Takehisa , Takeda Shinichi , Okahara Mitsuo , Komori Saburo
Published: July 2006

To study the reactivity of the sulfonamide radical in various reaction systems, the photodecomposition of N-t-butyl and N-methyl-N-chloroalkanesulfonamides was investigated. In benzene, the competitive hydrogen abstraction by the chlorine atom occurred to an appreciable extent and the participation of the chlorine atom was retarded with N2-flow control. In an aqueous solution (AcOH-H2O, t-BuOH-H2O), the quantitative conversion to γ-and δ-chloroalkanesulfonamide was observed; this was thought to be due to the intramolecular hydrogen abstraction by the sulfonamide radical and to the lowering of the reactivity of the chlorine atom because of the solvation by H2O. In an acid solution (AcOH-H2O-H2SO4), a higher preference for 1,5 hydrogen transfer was found; this was caused by the protonated sulfonamide radical. The formation ratio of γ- to δ-chloroalkanesulfonamide in several solvents was determined, and the reactivity of the sulfonamide radical was discussed. From the reaction products obtained, several aliphatic sultams were synthesized.
The Kinetics of the Reaction of Thiol Acids with Anilines
Authors: Hirabayashi Yoshio , Mizuta Masateru , Kojima Masana , Horio Yukio , Ishihara Hideharu
Published: July 2006

Studies have been made of the kinetics of the reactions of thiol acids (thiostearic acid and thioacetic acid) with anilines, such as aniline and p-methoxy-, p-ethoxy-, p-methyl-, m-methyl-, p-chloro, m-chloro-, and m-nitrosubstituted anilines, in a chlorobenzene solution. The rate is given by k(RCO–SH) (X-C6H4-NH2). The activation energy for the reaction of thiostearic acid with aniline is 5.3 kcal/mol. The Hammett plots give a straight line, with a value of ρ=−2.40 for the reactions of thiostearic acid or thioacetic acid with the anilines; the mechanism of the reaction of thiol acids with anilines is discussed.
Studies on Heteroaromaticity. LII. Syntheses and Reactions of α-Acetylenic Ketones Containing Nitrofuran Ring
Authors: Sasaki Tadashi , Yoshioka Toshiyuki
Published: July 2006

2-(5-Nitro-2-furyl)-1-phenyl- (IVa), -p-methylphenyl- (IVb) and -(2-furyl)-acetylene (IVc) were prepared by condensation of nitrofurfural with the corresponding aryl methyl ketones, followed by bromination and dehydrobromination. Addition of aniline and cyclohexylamine to IVa afforded simple adducts Va and VIa respectively. Treatment of IVa,b with hydroxylamine, hydrazine hydrate, semicarbazide and benzamidine gave isoxazoles (VIIIa,b), pyrazoles (VIIIa,b), 1-carbamidopyrazoles (IXa,b) and pyrimidines (Xa,b) respectively. When treated with benzonitrile oxide at room temperature, IVa afforded isoxazole XIa together with furoxan, but the thermal 1,3-dipolar reactions of IVa,b with 5-nitro-2-furocarbonitrile oxide afforded exclusively isoxazoles XIIa,b. For comparison, 5-nitro-2-furfurylidenebenzophenone (IIa) was treated with benzonitrile oxide at room temperature to afford an isomeric mixture of the isoxazolines XIIIa and XIVa together with furoxan. Similar treatment of 5-nitro-2-furfurylideneacetone afforded similar results affording a mixture of XV and XVI together with furoxan. When treated with phenacylpyridinium ylide, IVa,b afforded pyrrocolines XVIIa,b. The structural elucidation of the products was carried out on the basis of the spectral data.
Syntheses of 1,2,3-Trisubstituted 4-Aminoimidazolium Salts
Authors: Chinone Akiko , Sato Sigeru , Ohta Masaki
Published: July 2006

The salts of new mesoionic compounds of imidazole ring system having imino group at 4 position were synthesized by the reaction of amidines with haloacetonitriles. The resulting 4-amino-1,2,3-triphenylimidazolium salt was treated with sodium hydroxide to give an intermediate, N-cyanomethyl-N,N′-diphenylbenzamidine, which gave the salt of mesoionic imidazole with dry hydrogen bromide. 1,2,3-Trisubstituted 4-aminoimidazolium salts were treated with acetic anhydride or with picric acid or with silver perchlorate to give acetylated derivative, picrates and perchlorates, respectively.
An Interpretation of Mass Spectra of Disubstituted Benzenes by Simple LCAO MO Calculation. I
Authors: Tajima Susumu , Wasada Nobuhide , Tsuchiya Toshikazu
Published: July 2006

A part of the mass spectra for derivatives of aniline and anisole was interpreted using the results of MO calculation. Compounds studied were: aniline derivatives: o-, m-, and p-compounds of anisidine, aminophenol, chloroaniline, nitroaniline, aminobenzoic acid, and aminoaeetophenone; and anisole derivatives: o-, m-, and p-compounds of anisidine, methoxyphenol, chloroanisole, nitroanisole, methoxyben zoic acid, and methoxybenzaldehyde. The intensities of certain fragment ions in the mass spectra of these compounds were compared with the results of simple LCAO MO calculation for these compounds. A simple relation was found between the intensity and the partial bond order for a frontier electron of the bond ruptured.
Purity Determination of Organic Compounds by a Newly Designed DTA Apparatus
Authors: Mashiko Yo-ichiro , Shinoda Takako , Enokido Hisae
Published: July 2006

An apparatus of differential thermal analysis has been designed and constructed for the purpose of determining the purity of organic compounds with as small an amount of sample as possible, within a short time and yet with an accuracy of better than ±0.001 mol%. Degussa platinum thermometers were used. They were calibrated with a precision of better than ±0.004° against a standard platinum resistance thermometer. Methods for determining the impurities in samples on the basis of irreversible thermodynamics have been developed. The results were compared with those obtained by using an adiabatic calorimeter of our laboratory and by the National Bureau of Standards. The apparatus proved to be useful in determining the purity of about 1 ml of samples, whose melting points lie in the temperature range −200°C–+200°C within an accuracy of ±0.004 mol% in about 1.5 hr.
Normal Coordinate Treatment and Force Constants of Alkanonitriles
Authors: Fujiyama Tsunetake
Published: July 2006

Force constants of the Urey-Bradley type are calculated for a series of alkanonitriles. The calculation covers the mononitriles: CH3CN, CH3CH2CN, (CH3)2CHCN, (CH3)3CCN, and the dinitriles: NCCH2CN, NCCHDCN, NCCD2CN, trans-NCCH2CH2CN, gauche-NCCH2CH2CN. The results show that the force constants can be transferred from molecule to molecule as a group. It is also shown that a group of force constants is characteristic of a corresponding chemical structure or a substituent.
Polarized Absorption Spectra of Single Crystals of Ion Radical Salts. II. K(TCNQ) and Cs2(TCNQ)3
Authors: Hiroma Shoji , Kuroda Haruo , Akamatu Hideo
Published: July 2006

Polarized absorption spectra in the 10–40 kK region were observed on single crystals of the ion radical salts of tetracyano-p-quinodimethane (TCNQ), potassium·(TCNQ) and cesium2·(TCNQ)3. The crystal spectra are shown to be markedly different from the solution spectra of the monomer and dimer of TCNQ ion. It is shown that the 7.8 kK band of K(TCNQ) and the 11.1 kK band of Cs2(TCNQ)3 are charge-transfer bands associated with the transfer of an electron from a TCNQ− ion to the neighboring TCNQ− ion. The first-order and second-order effects were calculated on the local-excitation bands in order to explain the general feature of the observed spectra.
Studies on Salt Solution Aerosols. V. The Effect of Surface Active Substance upon the Droplet Size of an Aqueous NaCl Solution Aerosol
Authors: Ueno Yasuo , Sano Isamu
Published: July 2006

An aqueous NaCl solution (10%) containing a surface active substance was dispersed to a mist with a Dautrebande type atomizer. The influence of the surface active substance on the droplet size and mass concentration of the mist during aging was studied. We examined ethyl alcohol, acetic acid, ethyl acetate, acetone, glycerine, and a commercial nonionic surfactant. From the results it was found that at an early stage of aging, the droplet number present in mist was inversely proportional to the fourth power of droplet size.
The Catalytic Oxidation of Hydrogen on Titanium Dioxide; Anatase and Rutile
Authors: Onishi Yoshito
Published: July 2006

To clarify the reaction mechanism of catalytic oxidation of hydrogen on titanium dioxide, the rate of catalytic oxidation of hydrogen by oxygen and the reduction rate of titanium dioxide by hydrogen have been measured by a static method in temperature range of 400–650°C at 10−2 mmHg. The results were compared with those of carbon monoxide which were reported in the previous papers. The oxidation reactions of hydrogen on anatase and rutile were first order with respect to hydrogen and independent of the oxygen pressure. The oxidation rate was almost the same as the reduction rate of titanium dioxide by hydrogen. The activation energy was 29.2 kcal/mol for anatase and 17.8 kcal/mol for rutile, and the difference between these values for two crystal forms was nearly equal to that of the oxidation of carbon monoxide. Therefore, it may be considered that the mechanism of oxidation of hydrogen is analogous to that of carbon monoxide. The electric conductivity of the catalyst during the oxidation of hydrogen was larger than that in oxygen at the same temperature, and was still larger than that during the oxidation of carbon monoxide except for a few cases on anatase. There were close correlations between the electric conductivity and the amount of active oxygen of the catalyst and the reduction rate constant of titanium dioxide by both hydrogen and carbon monoxide.
Electron Donor-acceptor Complexes between Group IV Tetrahalides and Methylbenzenes
Authors: Hatano Masahiro , Ito Osamu
Published: July 2006

The charge-transfer bands of the loose complexes between Group IV tetrahalides (chlorides and bromides) and methylbenzenes were observed, and the electron affinities of these tetrahalides were systematically evaluated from these observed charge-transfer bands. The semi-empirical molecular orbital calculations (the extended Hiickel method) for these tetrahalides revealed that the tetrahalides interact with the benzene ring using the vacant molecular orbital involving the empty d atomic orbital of the halogen atom in the tetrahalides. Moreover, the meanings of the electron affinities estimated in this study were discussed in terms of the molecular orbitals, by comparing them with the values of the electron affinities evaluated by other methods.
An Infrared Spectroscopic Study of Hydrogen Bonds. The Liquid-Liquid Interaction of Solvents with Trimethylsilanol
Authors: Kagiya Tsutomu , Sumida Yūzō , Watanabe Takeshi , Tachi Toshihiro
Published: July 2006

An infrared spectroscopic study of the hydrogen-bonding interaction of binary solvents (S1–S2) with trimethylsilanol has been made, where CCl4 is used as S1 and the aromatic hydrocarbons and the O- and N-containing solvents, as S2. On the basis of the findings on the O–H frequency shifts (ΔνOH) of trimethylsilanol, the equilibrium constants (K) and the preferential coordination constants (α1−2) of hydrogen-bond formation, the difference in the O–H···π and the O–H···n hydrogen-bonding interactions has been discussed. The free-energy changes (−ΔG) were found to be better related to the apparent half-widths (Δν1⁄2) of the O–H bands than the ΔνOH. The ΔνOH of trimethylsilanol caused by the interaction with the solvent was in good correlation with the donor number defined as the heat of mixing of the solvent with antimony(V) chloride. From the linear relationship between the ΔνOH of trimethylsilanol and the ΔνSOH of the surface silanol caused by the gas-phase adsorption on silica gel, it was also found that the proton-donating power of the surface silanol was considerably larger than that of trimethylsilanol and was nearly equal to that of p-nitrophenol. There existed a linear relationship through the point of origin between the α1−2 and the separation factors (αS1−2) in the liquid-phase adsorption on the silica gel surface.
The Molecular and Crystal Structure of 3,4-Furandicarboxylic Acid Dimethylester
Authors: Okada Yasuyoshi , Nakatsu Kazumi , Shimada Akira
Published: July 2006

The crystals of 3,4-furandicarboxylic acid dimethylester are monoclinic of the space group P⁄21a, with unit cell dimensions a=12.64, b=8.16, c=7.97 Å, and β=100.0°. An approximate structure was determined by application of the symbolic addition phase determining procedure. After several cycles of least-squares refinement, the discrepancy index for the 901 observed reflections was reduced to 14%. In the molecule the furan ring is planar, and one carbomethoxy group is almost on the same plane as the furan ring, while the other makes an angle of 10.5° with the ring. The bond lengths and angles do not differ appreciably from the values found in the other compounds, except for those of C(3)–C(4)=1.41 Å, C(4)–C(3)–C(6)=131° and C(3)–C(4)–C(7)=132°, the latter two being larger than normal values probably because of interaction between the carbonyl-oxygens. The mode of packing of the molecules and a scheme of twinning found in this crystal is discussed.
Electronic Absorption Spectra of Crystals of Thymine, Uracil, and Their Derivatives
Authors: Tanaka Masashi , Tanaka Jiro
Published: July 2006

The electronic structures and spectra of thymine, uracil, and their derivatives have been studied by measuring the electronic absorption spectra of the single crystals. In the polarized absorption spectra of the crystal, an unusual absorption band appears at about 285 mμ in the tail of the usual π→π* transition when the crystal has the C=O···H–N-type hydrogen bond. The direction of the transition moment of this band is found to be along the direction of the hydrogen bond between a pair of C=O···H–N-groups, the nature of which is discussed from several viewpoints. The direction of the transition moment of the first and second π→π* bands is determined to be inclined at about +38° and +86° from the C4···N1 line toward the C5 atom. The result for the first band is not in perfect agreement with the finding of Stewart and Davidson regarding 1-methylthymine, who regarded this angle as either −14° or +19°.
Optical Activity of Nucleic Acid-Thionine Complexes
Authors: I’haya Yasumasa J , Nakamura Tomoyasu
Published: July 2006

The absorption spectra, optical rotatory dispersion, and circular dichroism (CD) of the DNA- and RNA-thionine complexes were measured at the nucleic acid phosphate to dye ratios (P/D) 0.01–50 and at the temperature range 20–85°C. The Cotton effects of P/D >3 complexes were observed in the wavelength region 520>680 nm, being resolved at least into four partial Cotton effects. From their transient profiles with changing P/D values and the observed temperature effect, they were interpreted to be induced from the dye monomers bound near the asymmetric environment of nucleic acids. The Cotton effects of P/D <2 complexes in the wavelength region 450–580 nm are new and have not been reported for other DNA-dye systems. The trough of these Cotton effects completely disappeared at 50°C and the decreasing profile of its relative rotation with increasing temperature was roughly parallel to that of the dimer fraction. The newly developed Cotton effects are inferred to result from an interaction between the dye dimers aggregated in a helical fashion along the nucleic acid helices. The negative sign CD maximum observed in the wavelength region 300–330 nm is probably due to DNA-dye interactions, but its origin is not clear.
The Preparation and Nonstoichiometry of Samarium Hexaboride
Authors: Niihara Koichi
Published: July 2006

Samarium hexaboride was prepared by the borothermal reaction; 2 Sm2O3+(6+4x)B=4 SmBx+3 B2O2. The residual oxygen content amounted to less than 0.03 w/o under optimum reaction conditions heating at 1650°C for 2 hr under a high vacuum. It was found by X-ray intensity and density measurements that the samarium hexaboride stayed stable over a large nonstoichiometric region from Sm0.68B6 to SmB6. These extensive nonstoichiometric properties of samarium hexaboride can be explained in terms of the required electron numbers of the SmB6 network in hexaboride.
Observation and Interpretation of Triplet-Triplet Absorption Spectra of Substituted Naphthalenes
Authors: Takemura Takeshi , Hara Kiyoaki , Baba Hiroaki
Published: July 2006

Triplet–triplet (T–T) absorption spectra of naphthalene, α- and β-methoxynaphthalene have been observed in rigid-glass solutions at 77°K by the rapid-scan spectrophotometric method and in fluid solutions at room temperature by the flash spectroscopic method. Hydrogenbonding effects on the T–T absorption spectra were examined for α- and β-naphthol. α-Naphthol was found to give different absorption spectra, depending upon the solvents employed. In a certain case the spectrum is attributed to a photoproduct rather than to the triplet state of a-naphthol. Analysis of the spectral data leads to the conclusion that the T–T absorption spectra in α-derivatives involve two different electronic transitions, and those in β-derivatives are due to a single electronic transition which is analogous to the transition in naphthalene. In agreement with these observations, calculations performed by the Pariser-Parr-Pople method predict that in the low-energy region, α-naphthol should have two allowed and detectable transitions, 3Ψ1→3Ψ7 and 3Ψ1→3Ψ8, and naphthalene and β-naphthol have only one such transition, 3Ψ1→3Ψ9. The wave functions of triplet states are subjected to configuration analysis, with the result that 3Ψ7 and 3Ψ8 of α-naphthol are related predominantly to 3Ψ8 and 3Ψ9 of naphthalene, respectively.
The Role of Reaction Sites in the Radiolysis of Solid Succinic Acid
Authors: Miyazaki Tetsuo , Fujitani Yoshiteru , Wakayama Terunobu , Fueki Kenji , Kuri Zen-ichiro
Published: July 2006

The main gaseous products in the radiolysis of solid succinic acid are CO2, CO, and H2. It was found that the G(CO+H2) from the powder is much higher than that from the single crystal, while there is no difference in G(CO2) between the powder and the single crystal, indicating that CO2 is produced homogeneously in the solid. The clear difference in the G(CO+H2) between the powder and the single crystal cannot be attributed to the analytical procedure, the secondary reaction of CO, or the presence of H2O as an impurity. It may be due to the difference in the primary process of the radiolysis. It is conceivable that the mobile active entity formed by the γ-irradiation of the crystal migrates to the special reaction sites and produces CO and H2. The difference in G(CO+H2) may also be due to the different numbers of the sites between the powder and the single crystal. It is discussed whether the mobile entity is a cation, an electron, or an exciton.
Dielectric Relaxation and Molecular Structure. VI. Dielectric Measurements at the Frequency of 100 GHz
Authors: Chitoku Kazuo , Higasi Keniti , Nakamura Masahiko , Koga Yoshinori , Takahashi Hiroaki
Published: July 2006

This paper gives details of the equipment and the method of the measurement at 100 GHz. Dielectric constants and losses are measured at this frequency for ten organic molecules in benzene and four (aniline, phenol, and its derivatives) both in benzene and in dioxane. A majority of the molecules studied are of non-rigid configuration. Discussion is given of the relaxation times and the mechanism of internal rotation involved. Hydrogen bonding effects in aniline, phenol, and its derivatives are also discussed.
Osmotic Pressures of Polystyrene, Poly-p-chlorostyrene and Poly-o-chlorostyrene Solutions
Authors: Kubo Kenji , Ogino Kazuyoshi
Published: July 2006

Second virial coefficients for polystyrene (PS), poly-p-chlorostyrene (PPCS), and poly-o-chlorostyrene (POCS) were determined in various solvents by osmotic-pressure measurements. Free-energy parameters, χ, were estimated from the values of the second virial coefficients. It was shown that the values of χ in each solvent at 30°C became larger in the following order: PS, POCS, PPCS in toluene; PS, PPCS, POCS in chlorobenzene; PPCS, PS, POCS in n-butyl acetate. It was indicated that, in addition to the effect of intermolecular forces, another parameter related to the stiffness of the polymer chains should be considered in order to discuss the thermodynamic properties of polymer solutions. It was shown that the values of χ for two polychlorostyrenes in n-butyl acetate increased with an increase in the temperatures, unlike the behavior of PS in the same solvent.
Magnetic Properties of Copper(II) Complexes of 6-Aminopurine and 6-Hydroxypurine
Authors: Asakawa Toshiro , Inoue Motomichi , Hara Ken-ichi , Kubo Masaji
Published: July 2006

The magnetic susceptibilities of bis(6-aminopurinato)copper(II) trihydrate, dichlorobis(6-aminopurine)copper (II) sesquihydrate, and dichlorobis(6-hydroxypurine)copper(II) monohydrate obey the Bleaney-Bowers equation for binuclear clusters in conformity with the results of X-ray crystal analysis. The exchange integrals within binuclear clusters were evaluated as J⁄k=−156 to −208°K. Superexchange interaction rather than the interaction of direct nature operates predominantly between copper atoms through the pπ orbitals of the heterocycles. The J⁄k values of the compounds are nearly equal to the value, −204°K, of copper(II) acetate monohydrate, although the Cu–Cu distance in the former is greater than that in the latter. The magnetic susceptibilities of dibromobis(6-aminopurine)copper(II) dihydrate, dibromobis(6-hydroxypurine)copper(II) dihydrate, dichloro(6-aminopurme)copper (II), dichloro(6-hy droxypurine)copper (II) monohydrate, and dibromo(6-hydroxypurine)copper(II) hemihydrate indicate the presence of paired copper atoms in the crystals.
Infrared Intensities of Crystalline HCN and DCN
Authors: Uyemura Masakatsu , Maeda Shiro
Published: July 2006

The absolute infrared intensities of crystalline HGN and DCN were measured at the temperature of liquid N2. In comparison with the gaseous values, both stretching fundamentals (v1, v3) exhibited a striking increase in the integrated absorption, while the bending (v2) was almost unchanged. From the observed intensity change, the change in the dipole-moment derivatives with respect to the molecular internal coordinates was calculated to be ∂ΔM⁄∂rC=N=1.43 D/Å and ∂ΔM⁄∂rC−H=2.01 D/Å, those values were chosen from two alternative possibilities as the more probable set. The significance of these values, however, is somewhat peculiar to the optically-active crystalline vibrations, so they were then resolved into derivatives with respect to purely intramolecular and intermolecular coordinates: [∂ΔM⁄∂rC−H]=0.58 D/Å and [∂ΔM⁄∂rH···N]=−1.43 D/Å. The general intensity features were reasonably interpreted by considering the contribution of a charge-transfer structure to the H–N hydrogen bonding.
Activation of Iron-Alkyl Bonds in Dialkylbis (dipyridyl) iron(II) by Interaction with Olefins
Authors: Yamamoto Takakazu , Yamamoto Akio , Ikeda Sakuji
Published: July 2006

The reactions of dialkylbis(dipyridyl)iron (II) 1 with various substituted olefins were studied. Tetracyano-ethylene, maleic anhydride, and acrylamide gave olefin-coordinated π-complexes on reactions with 1, whereas other vinyl monomers with relatively large e-values were polymerized by the alkyl-iron complex. Kinetic study of the reactions of 1 with olefins by a spectroscopic method revealed that the reaction rate can be expressed by

−\fracd[FeR2(dipy)2]dt=\frac[olefin][FeR2(dipy)2]A+B[olefin]+C[dipy]

On the basis of kinetic results and from comparison with the reactions of dialkyl(dipyridyl)nickel with olefins, a mechanism involving partial dissociation of the dipyridyl ligand from 1, followed by a coordination of the olefin and activation of a Fe-alkyl bond was proposed.
The Stereochemistry of Nucleophilic Addition. IV. The Condensation of 2,2,6-Trimethylcyclohexanone with t-Butyl Acetate in the Presence of Lithium Amide
Authors: Matsumoto Takashi , Sakata Gojo , Tachibana Yakudo , Fukui Kenji
Published: July 2006

The stereochemistry of the condensations of 2,2,6-trimethylcyclohexanone with t-butyl acetate in the presence of lithium amide, with ethyl bromoacetate in the presence of zinc (Reformatsky reaction), and with ethylmagnesium iodide (Grignard reaction) was studied. The configurations of the products in these reactions were assigned on the basis of their chromatographic behavior, and on the basis of spectroscopic and chemical studies of them. From the present experiments it is evident that all of these nucleophilic addition reactions proceed in a similar fashion. Further, the treatment of t-butyl 1-hydroxy-2,2,t-6-trimethyl-r-1-cyclohexaneacetate (IIa) with potassium hydrogensulfate or with dilute sulfuric acid gave (±)-cis-tetrahydroactinidiolide (IX), which was isolated from the essential oil of cigar tobacco leaves by Kaneko and Hoshino, while the treatment of IIa with isopropenyl acetate in the presence of p-toluenesulfonic acid gave a mixture of IX and its trans-isomer (X).
Carbon-13 Magnetic Resonance Chemical Shifts in Alkylbiphenyls
Authors: Hasegawa Hideo , Imanari Mamoru , Ishizu Kazuhiko
Published: July 2006

Carbon-13 NMR spectra were observed for the seventeen alkyl biphenyls. For the meta- and para-alkyl derivatives, the observed ring carbon-13 chemical shifts could be adequately understood in terms of the Karplus-Pople’s formula by taking into account the hyperconjugative effect of the substituents. The observed chemical shifts of aliphatic carbon were in good agreement with the values of the corresponding alkylated benzenes within the limits of experimental error. For the ortho-derivatives, the conformation of substituents in the hindered biphenyls was particularly discussed in relation to the observed alkyl carbon-13 chemical shifts. In the cases of 2,2′-dimethylbiphenyl and 2,2′,6,6′-tetramethylbiphenyl, the chemical shifts of methyl carbons at the ortho-position revealed a high field shift of about 1 ppm, but that of 2,4,6-trimethylbiphenyl indicated only 0.4 ppm. The different shifts of the ortho-methyl carbons in the two cases suggested a spece interaction between the two methyl groups. This interaction may arise an orbital overlap between the methyl groups, which were considered to approach one another to take the cis-conformation.
Phenolyses of 1-Adamantyl Chloride, Bromide, and p-Toluenesulfonate in Binary Mixtures of Phenol with Benzene. The Rates and the Product Distribution
Authors: Okamoto Kunio , Matsubara Kôichi , Kinoshita Tomomi
Published: July 2006

Adamantyl derivatives, the bridgehead substrates, have been chosen as the reference compounds in the assessment of the ionizing power of phenolic solvents in the ,SN1-type solvolysis. The SN1-phenolyses of 1-adamantyl chloride, bromide, and p-toluenesulfonate have been studied at several temperatures in binary mixtures of phenol with benzene; the enthalpies and entropies of activation have been calculated. Phenolysis has also been made on t-butyl chloride in order to estimate the Grunwald-Winstein Y values for the phenol-benzene solvents. The solvolysis rates of 1-adamantyl compounds, including the literature values, have been correlated with the Y values and also with the dielectric constants ((D−1)⁄(2D+1)). A significant deviation is found for the phenolic solvents in both correlations; this deviation is discussed in terms of the electrophilic assistance by hydrogen-bonding of the phenolic solvents to the leaving group. The isolated phenolysis products have been characterized as 1-adamantyl phenyl ether, o-, and p-1-adamantylphenols. The product compositions for the reactions of the ion-pair intermediate with the phenol molecule and with the phenoxide ion have been estimated on the basis of the variation in the overall product compositions, caused by the increase in the concentrations of the added phenoxide or amine.
The Substituent Effect. I. Normal Substituent Constants from the Hydrolysis of Substituted-benzyl Benzoates
Authors: Yukawa Yasuhide , Tsuno Yuho , Sawada Masami
Published: July 2006

The rates of the alkaline hydrolyses of 24 m- and p-substituted-benzyl benzoates were measured in 70% (v/v) aqueous acetone at 25°C. The given set of σ0 constants was precisely identical with our standard set derived from m- and p-substituted ethyl phenylacetates. The general utility of σ0 constants is demonstrated for unexalted and exalted resonance reactivities as the reference scale in our LArSR equation:

logk⁄k0=ρ(σ0+r+Δ\barσ\overset+R+r−Δ\barσ\overset−R)
Magnetic Circular Dichroism Studies on High-intensity Bands of d8 Square-planar Metal Halides
Authors: Katô Hajime
Published: July 2006

The magnetic circular dichroism (MCD) of certain d8 square-planar metal halides is studied theoretically on the basis of the molecular orbital theory. The ground state wavefunctions of PtCl42− and PdCl42− are calculated by the semi-empirical ASMO SCF MO method for valence electron systems. The line shape of the MCD of the allowed transition is investigated in detail; the calculated line shape is in good agreement with the observed line shape. The results strongly suggest that the transitions at 43400 cm−1 and 46200 cm−1 in PtCl42− are 1A1g→1A2u(b2u—3b1g and 3a1g—2a2u) and 1A1g→1Eu(5d—6p) respectively, and that the transition at 44900 cm−1 in PdCl42− is 1A1g→1Eu(1).