bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on Stable Free Radicals. IV. Decomposition of Stable Nitroxide Radicals
Authors: Murayama Keisuke , Yoshioka Takao
Published: July 2006

Decomposition studies of extremely stable free radicals such as 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (I), 2,2,6,6-tetramethylpiperidine-1-oxyl (VIII) and 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl (IX) were carried out: although radical I decomposed to give 1-hydroxy-2,2,6,6-tetramethyl-4-oxopiperidine (IV) both in the light and dark, radicals VIII and IX were more stable under these reaction conditions. Therefore it was confirmed that i) a source of hydrogen was the ketonic α-methyene hydrogens, ii) a radical which could give a thermodynamically stable conjugated product by a cycloelimination was easily decomposed and iii) the decomposition of radical I was only accelerated by heating and was independent of the action of light.
Studies of the N-Oxides of N,N-Dialkylamino Acids. II. The Syntheses of N,N-Dialkylglycine and Corresponding N-Oxides
Authors: Ikutani Yoshikazu
Published: July 2006

The reductive condensations of glycine with various aliphatic straight-chain aldehydes, such as acetaldehyde, propionaldehyde, and n-butyraldehyde, give the corresponding N,N-dialkyl derivatives. The N-monoalkyl derivative has not been obtained in any case. In another type of reactions, those with aliphatic branched-chain aldehydes, such as isobutyraldehyde and isovaleraldehyde, considerable N-monoalkylation takes place besides the dialkylation. The oxidations of N,N-dialkylglycine to the corresponding N-oxides have been successfully performed using an aqueous mixture of hydrogen peroxide and acetic acid except in the case of N,N-diisobutylglycine. Similar reductive condensations of sarcosine with various aliphatic aldehydes, such as acetaldehyde, propionaldehyde, n- and iso-butyraldehyde, and isovaleraldehyde, gave the corresponding N-alkylsarcosines. N-Isobutyl and N-isoamyl sarcosine were also obtained by the methylation of the corresponding N-monoalkylglycine. The N-oxides of N-alkylsarcosine were synthesized by a procedure similar to that described above.
The Acidic Nature of Synthetic Zeolites: Acid Strength and Its Correlation with the Catalytic Activity
Authors: Otouma Hiroshi , Arai Yoshimasa , Ukihashi Hiroshi
Published: July 2006

The acidic characters of the X and Y zeolites exchanged by hydrogen, calcium, and lanthanum ions were investigated. Very characteristic features of the acid sites were found as compared with those of an amorphous silica-alumina cracking catalyst. The acidity is generally larger in the zeolites (2–3 meq/g) than in a silica-alumina (0.5 meq/g). The acid strength is more widely distributed in the zeolites (H0=+3.3−<−8.2) than in a silica-alumina (H0<−8.2). Very important is the fact that the acid site increases not only in number but also in strength with an increase in the degree of ion exchange. The results on cumene cracking are in line with these results.
Vacuum-ultraviolet Absorption Spectra of Aliphatic Ketones
Authors: Ito Hiroyuki , Nogata Yoshihiko , Matsuzaki Sanae , Kuboyama Akira
Published: July 2006

The molar-absorptivity curves of various aliphatic ketones, mainly methyl alkyl ketones, in the gaseous state in the region from 1650 to 2000 Å have been obtained. In these ketones the absorption bands near 1950 Å and 1700 Å are denoted as A and B bands respectively. Di-n-propyl and diisopropyl ketones show, besides the A and B bands, an absorption band near 1650 Å (C band). The relations between the obtained spectra and the molecular structures of these ketones have been studied. On the basis of this study, the characteristics of the electronic transitions of A, B, and C bands have been discussed.
Determination of S*-T Transition Probabilities of Some Xanthene and Thiazine Dyes on the Basis of T-Energy Transfer. II. Results in the Aqueous Solution
Authors: Nemoto Masae , Kokubun Hiroshi , Koizumi Masao
Published: July 2006

Intersystem crossing probability \varphiSTA for fluorescein, eosin, erythrosin, methylene blue and thionine in the aqueous solution of pH 7.2 (only for fluorescein 0.05n NaOH solution) has been determined by comparing the quantum yield of the nonsensitized (Φ) and the sensitized photo-reduction (ΦS) on the basis of the relations

Φ=\varphiSTAβA ΦS=\varphiSTDβγA,

where βA is the fraction of triplet dye molecules that undergo reduction, \varphiSTA and \varphiSTD are respectively for acceptor (dye) and donor (sensitizer), and γ is the energy transfer efficiency. This was assumed as unity. ATU and EDTA were used as a reducing agent. 1,5-Naphthalenedisulfonic acid and 1-anthracenesulfonic acid were used as sensitizers. The above relations and assumption have been found to hold satisfactorily. The \varphiSTD values for two sensitizers were determined using erythrosin as a reference substances for which \varphiSTA was assumed to be unity. \varphiSTD obtained was 0.88 for 1,5-naphthalenedisulfonic acid, and 0.82 for 1-anthracenesulfonic acid. \varphiSTA values for dyes obtained were: fluorescein (0.021) eosin (0.64) erythrosin (1.0) methylene blue (0.52) thionine (0.55). Using these \varphiSTA values, the rate constants for the following elementary reactions have been evaluated (A, dye: RH2 reducing agent): AT+RH2→reaction, AT+RH2→deactivation, AT+A→reaction or deactivation.
Role of the Solvent in the Distribution of the Zinc-TTA Chelate and the Adduct Formation with TBP
Authors: Akiba Kenichi , Suzuki Nobuo , Kanno Takuji
Published: July 2006

The distributions of the zinc chelate with thenoyltrifluoroacetone (TTA) between an aqueous solution and twelve inert organic solvents were investigated. After it had been confirmed that the distributed species were ZnA2, the distribution coefficients of the chelate (PM) and those of TTA (PHA) were compared; it was found that there is a correlation which can be expressed as logPM=nlogPHA+const. When TTA and TBP are in the extraction system, the adduct formation constants of chelate were obtained. The activities of all the species which take part in the adduct formation were evaluated on the basis of the regular solution theory. It was found that the adduct formation constant in terms of activity (Ks°) is constant in all the organic solvents; namely, logKs° was found to be 4.05. Finally, the role of the solvent in the synergistic extraction system is explained systematically by a combination of the regularity in the distribution and that in the adduct formation.
A New Acidity Function, T0, in Acid-catalyzed Reactions
Authors: Takaya Haruo , Todo Naoyuki , Hosoya Tadasuke
Published: July 2006

In acid-catalyzed reaction systems a new acidity function, T0, which is related to the first-order rate constant, k1 by the equation log k1=C−T0 was defined by T0=−log (aH+/awh5−h1f\eweq) and was theoretically calculated in much the same manner as in Glueckauf’s treatments on a salt solution but with the additional assumption that the character of a hydrated univalent activated complex is represented by that of a hydrated alkali metal cation. The calculated results show that T0 in hydrochloric acid can be represented by:

T 0=2.4(3.9−h1+h5)logaw−logma.

This equation shows that if the hydration number (the water molecules bound with an activated complex) of an activated complex, h1, increases by one, the corresponding increment of T0 becomes −2.4logaw. It was also shown that the value of fAH+fB⁄fAfBH+ is not always constant, but depends on the hydration numbers of the AH+ and BH+ species as well as on the acid concentrations. The factors affecting the acidity function, T0, were compared with those affecting the activity of water. The applicability of the T0 was examined by means of the observed logk1 value reported by Bunnett.
Effects of Substitution on the Phosphorescence Process of Aromatic Carbonyl Compounds
Authors: Takemura Takeshi , Baba Hiroaki
Published: July 2006

Phosphorescence and absorption spectra, phosphorescence- and excitation-polarization, spectra and phosphorescence lifetimes were measured at 77°K for benzaldehyde, acetophenone and their eight derivatives with a halogen atom, or a hydroxyl, methoxyl or amino group as a substituent at the para position. In chloro- and bromo-derivatives, the phosphorescent triplet state is of the (n,π*) type, and is mixed with the 1La(π,π*) state by direct spin-orbit interaction, as in the case of the parent carbonyls. In addition, owing to the heavy-atom effect, it gains its singlet character by the mechanism

(Remark: Graphics omitted.)

which accounts for the observation that the phosphorescence spectrum involves out-of-plane-polarized vibrational bands. Substitution of a more electron-donating hydroxyl, methoxyl, or amino group brings about a change of the phosphorescent state from the 3(n,π*) state to the; 3La(π,π*). The following mechanisms are shown to be important to the 3La(π,π*) state:

(Remark: Graphics omitted.)

These account for two progressions with mutually perpendicular polarizations observed in the phosphorescence spectrum. The lifetimes for the transitions from the 3La(π,π*) state to the ground state of the substituted carbonyls were found to be substantially shorter than the corresponding lifetimes in aromatic hydrocarbons. This fact is quantitatively interpreted as due to the presence of a low-lying 1(n,π*) state.
Concentration Polarization Phenomena in Ion-exchange Membrane Electrodialysis. I. Studies of the Diffusion Boundary Layer by Means of Six Different Measurements
Authors: Sata Toshikatsu , Yamane Reiichi , Mizutani Yukio
Published: July 2006

The behavior of the diffusion boundary layer in the electrodialysis using ion-exchange membranes, mainly a cation-exchange membrane, was studied by means of six different measurements: 1) the determination of the current-voltage curve or the current-(voltage/current) curve; 2) the relation of the pH change of the solution to the current density; 3) the relation of the charge retention, i.e., the sum of the diffusion potential and the membrane potential generated from the concentration gradient across the membrane immediately after the current is shut off, to the current density; 4) the time required to reach a constant current value, namely, to obtain a stationary diffusion boundary layer, when a constant voltage is supplied to the system, versus the current density; 5) the change in the transport number of the counterion in the membrane with the current density, and 6) the relation of the permselectivity between sodium ions and potassium ions to the current density. The interrelation among these results was also examined. The quantity of hydrogen ions or hydroxide ions passing through the membrane increases abruptly at a current density lower than that at which the concentration at the membrane-solution interface in the desalting side attains its minimum. It was newly observed that the results of all the measurements, except for the pH change of the solution, show abnormal phenomena at a current density about twice the limiting current density.
Vapor Pressure of Carbon Monoxide in Condensed Phases
Authors: Shinoda Takako
Published: July 2006

A theoretical vapor pressure equation of the form logP+(3⁄2)logT=a+b⁄T for a diatomic molecule was applied to carbon monoxide in condensed phases. The two parameters in the equation determined from experimental vapor pressure data were used to obtain values of the static lattice energy E0, the zero point energy Ez, the geometric mean frequency ωg and the mean frequency of molecular rotation ωR in the respective phases by the information of lattice vibrations at low temperatures. From the mean values of molecular rotation frequencies, the hights of the potential barrier for hindered rotations were estimated to be 360, 230±10 and 110 cal/mol respectively.
Separation and Identification of Chlorocomplexes of Technetium(IV) formed in Hydrochloric Acid Solutions
Authors: Kanchiku Yoshihiko
Published: July 2006

The chemical behavior of TcCl62− in HCl solutions of different concentrations has been investigated. It was confirmed that TcCl62− is sensitive to ultraviolet and visual light, giving a series of aquated species the quantities of which depend on the HCl concentration. Those technetium(IV) chlorocomplexes were isolated by means of ion-exchange and paper electro-phoresis, and the composition of each species was determined by measuring the Cl/Tc ratio and the charge per species. The absorption spectra of isolated species were also measured.
The Mechanism of the Base-Promoted Rearrangement of N,N-Dichlorocyclohexylamine to 2-Aminocyclohexanone and the Deaminative Diazotization of 2-Aminocyclohexanone
Authors: Nakai Mamoru , Furukawa Naomichi , Oae Shigeru
Published: July 2006

N,N-Dichlorocyclohexylamine-1-14C has been treated with sodium methoxide in methanol and then with hydrochloric acid to yield 14C-labeled 2-aminocyclohexanone hydrochloride. Successive degradations have revealed that practically all the 14C activity was found in the carbonyl carbon of the original aminoketone. From the 14C distribution, it has been concluded that the reaction is essentially the same as that proposed for the Neber rearrangement. As a part of the degradation of 2-aminocyclohexanone, deaminative diazotization was employed to obtain cyclopentanecarboxylic acid together with other minor products. The 14C tracer work revealed that the carbonyl group of the acid is originated from the carbonyl group of the 2-amino-ketone.
Studies on s-Triazines. I. Cotrimerization of Trichloroacetonitrile with Other Nitriles
Authors: Wakabayashi Ko , Tsunoda Masaru , Suzuki Yasushi
Published: July 2006

2-Substituted 4,6-bis(trichloromethyl)-s-triazines have been prepared by the cotrimerization of CCl3CN with some nitriles. The reaction proceeds, in general, smoothly at ordinary pressure in the presence of hydrogen halide or Friedel-Crafts catalyst-hydrogen halide complex. An improved method was developed for the nitriles such as propionitrile with which CCl3CN did not easily cotrimerize under above mentioned conditions.
The Intensity of the n–π* Absorption Bands of Several Aliphatic Carbonyl Compounds
Authors: Ozeki Kayoko , Inagaki Masaji , Tanaka Jiro
Published: July 2006

The mechanism of the intensity gain of the n–π* transition has been investigated in several carbonyl compounds; (1) cyclohexane-1,4-dione, (2) d-α-bromocamphor, (3) bromonoranisatinone, (4) d-α-cyanocamphor, and (5) spiradine A methiodide. The results on the polarized absorption spectra of single crystals at room temperature have revealed that several mechanisms are involved in the appearance of the carbonyl n–π* band. These mechanisms, (1) the vibronic coupling, (2) the lowering of the symmetry properties of the n and π orbitals by the substituent perturbations, and (3) the charge transfer from the substituents, are discussed theoretically and compared with the experimental results. It is shown that the in-plane components, either parallel or perpendicular to the carbonyl axis, are predominant as the source of the band intensity. The ratio of intensities parallel and perpendicular to the carbonyl axis is estimated by the use of the polarization results.
The Crystal and Molecular Structure of the Sodium Salt of Xanthine
Authors: Mizuno Hiroshi , Fujiwara Takaji , Tomita Ken-ichi
Published: July 2006

The crystals of sodium salt of xanthine, C5H3N4O2Na·4H2O, are monoclinic with four molecules in a unit cell of dimensions; a=7.31, b=19.52, c=7.17 Å, β=100.0°, space group P21⁄c. The structure has been determined by application of the sign relationship S(hkl)S(h′k′l′)∼S(h+h′,k+k′,l+l′) from (hk0) intensity data and refined by three-dimensional least-squares methods. The positions of the hydrogen atoms were determined by a three-dimensional difference Fourier analysis, and it was confirmed that deprotonation took place at the position of the imino N(3)H of the xanthine molecule. Each Na+ cation is surrounded by six water molecules and each xanthine anion participates in ten hydrogen bonds, forming a close-packed system.
Total Syntheses of Tanshinone-I, Tanshinone-II and Cryptotanshinone
Authors: Inouye Yoshinobu , Kakisawa Hiroshi
Published: July 2006

Total syntheses of tanshinone-II (II) and cryptotanshinone (III) from 3-methylbenzofuran-4, 7-quinone (X) and 6,6-dimethyl-l-vinylcyclohexene (IX), and of tanshinone-I (I) from quinone X and o-methylstyrene (XVIII) are described. Preliminary accounts for the Diels-Alder reaction of methoxybenzoquinone revealed that the effect of substituents for orientation phenomena can be considered to be of electronic nature.
Studies of Helical Aggregates of Molecules. I. Enantiomorphism in the Helical Aggregates of Optically Active 12-Hydroxystearic Acid and Its Lithium Salt
Authors: Tachibana Taro , Kambara Hideko
Published: July 2006

It was found, by electron-microscope observation, that d(or l)-12-hydroxystearic acid and its Li soap crystallize from a solution in various solvents in the form of a twisted fiber. The twist was left-handed for the d-acid and right-handed for the l-acid, while the Li soap gave results just opposite to those of the corresponding acid. The Dl-acid separated out not fibers, but platelike crystals, and its Li soap produced non-twisted fibers. Thus, an enantiomorphic relationship for the sense of twist between the d-enantiomer and the l-enantiomer was found both for the acid and for the Li soap.
The “Circular Dichroism-sensitive Band” in the Optical Absorption of the Lanthanide(III) Complexes with Some Optically Active Ligands
Authors: Misumi Seizo , Kida Sigeo , Isobe Toshiyuki , Nishida Yuzo , Furuta Haruko
Published: July 2006

The circular dichroism and absorption spectra of Pr(III), Nd(III), Sm(III), Dy(III), Ho(III), Er(III) and Tm(III) complexes with some natural amino acids and L-EDDS have been measured at room temperature. The “circular dichroism-sensitive bands” have been observed on the J-bands where magnetic dipole transitions are allowed to some extent. The experimental results are in accordance with the theory proposed previously. The theory can be applied at least for lanthanide(III) complexes.
An MO-Theoretical Study of Several Bimolecular Reactions of Nucleophilic Reagents
Authors: Fukui Kenichi , Hao Hideyuki , Fujimoto Hiroshi
Published: July 2006

The relative ease of the occurrence of SN2 and E2 reactions and the mechanism of related bimolecular processes, such as the base-catalyzed hydrolysis of carboxylic esters and the acid-catalyzed halogenation of aliphatic ketones, are discussed in connection with the MO-theoretical reactivity indices. The results indicate that the valence-inactive populations in the lowest unoccupied (LU) MO are useful reactivity indices for these nucleophilic reactions.
Some Remarks on the Fragmentation of Excited Ions in the Radiolysis of Hydrocarbons
Authors: Miyazaki Tetsuo , Tanno Kuniyasu , Shida Shoji
Published: July 2006

The fragmentation of excited ions in the liquid-phase radiolysis of hydrocarbons is explained by a new mechanism, which involves the fragmentation of a highly excited ion (M+**). The M+** ion is considered here to be the electronic excited states and to decompose by the following mechanism. The electronic excitation energy can spread over all C–C bonds in a molecule before its fragmentation and, when the mean excitation energy per C–C bond exceeds its bond energy, the excited ion decomposes instantaneously in one vibration. Further, the mass spectra of isobutane and isooctane are calculated by a simplified quasi-equilibrium theory by introducing the highly excited ion and are compared with experimental mass spectra and with the calculated values without introducing the highly excited ion.
The Formation of Transient Aromatic Ions in Solutions by the Flash Illumination
Authors: Kawai Kiyoshi , Yamamoto Naoto , Tsubomura Hiroshi
Published: July 2006

Flash illumination of an oxygen-free acetonitrile solution containing p-dimethoxybenzene (DMB) and s-trinitrobenzene or chloranil gave a transient absorption spectrum of DMB cation. The decay of the transient absorption spectra follows the second-order reaction kinetics proving that the decay is brought about by the recombination of the anion and the cation after the flash illumination. The formation of the ion-pair may be explained as follows:

(Remark: Graphics omitted.)
Polarographic Study of Copper(II)-N-(2-Hydroxyethyl)ethylene-diamine-N,N′,N′-triacetate and -2,2′-Ethylenedioxybis-[ethyliminodi(acetate)] Chelates
Authors: Kodama Mutsuo , Tominaga Yayoe
Published: July 2006

D.c. polarographic behavior of copper(II) ion in N-(2-hydroxyethyl)ethylenediamine-N,N′N′-triacetate (EDTA-OH) and 2,2′-ehtylenedioxybis[ethyliminodi(acetate)] (GEDTA) solutions was studied systematically. In an EDTA-OH solution, copper (II) ion gave invariably a single well-defined wave corresponding to the following two-electron reduction.

GuX−+nH++Hg+2e−\ightleftarrowsCu(Hg)+HnXn−3

On the other hand, in a GEDTA solution, two waves were obtained. The height of the first wave, which is reversible in nature, increases with increasing pH of the solution at the expense of the height of the irreversible second wave. From the relation between the half-wave potential and the concentrations of hydrogen ion, GEDTA and acetate ion, determined experimentally, the compositions and the stability constants of copper(II)-GEDTA chelates in solution were determined and the electrode reaction mechanism established:

(Remark: Graphics omitted.)
The 1:1 Complexes of Pyridine-2-carboxamide with Bivalent Metals
Authors: Sekizaki Masao , Tanase Masakazu , Yamasaki Kazuo
Published: July 2006

The 1 : 1 complexes of pyridine-2-carboxamide (piaH) with the bivalent metals, nickel, copper, cobalt, zinc and cadmium, were prepared and their structures determined through measurements of diffuse reflectance spectra, magnetic moments and infrared spectra. In these complexes, MX2-(piaH) (X=halogen), pyridine-2-carboxamide is likely to be coordinated to the metal through N(pyridine) and O(amide) atoms with two halogen atoms in the cis-position.
Anomalous Magnetic Properties of Stable Crystalline Phenoxyl Radicals
Authors: Mukai Kazuo
Published: July 2006

The results of static magnetic susceptibility measurements in the 1.8–300°K temperature range are reported on powder samples of the stable aromatic free radicals: 2,6-di-t-butyl-4(3,5-di-t-butyl-4-oxocyclohexa-2,5-dienylidene methyl) phenoxyl (Galvinoxyl) and 2,6-di-t-butyl-4(3,5-di-t-butyl-4-oxocyclohexa-2,5-dienylidene amino) phenoxyl (BIP) radicals. The susceptibility of Galvinoxyl follows the Curie-Weiss law above Tc=81±1°K, depending on the sample, with a Weiss constant of 11±3°K. However, at Tc=81°K, χp rapidly decreases, and below 66°K the susceptibility again increases, with different spin concentrations for independently-prepared samples as the temperature is lowered. A maximum at 81°K was also found by the EPR measurements; the anomaly of the susceptibility at this temperature is probably due to a first-order phase transition induced magnetically, accompanying the pairing of magnetic spins, judging from the results of differential thermal analysis and the magnetic susceptibility measurements. On the other hand, the magnetic susceptibility of the BIP radical exhibits a broad maximum at 54±2°K. This susceptibility can be explained approximately using a model which consists of a singlet ground state and a triplet state lying slightly above the ground state.
Studies of Actinium(III) in Various Solutions. II. Distribution Behavior of Lanthanum(III) and Actinium(III) in Some Chelate Extraction Systems
Authors: Sekine Tatsuya , Koike Yasuaki , Hasegawa Yuko
Published: July 2006

Distribution behavior of lanthanum(III) and actinium(III) at tracer concentrations was studied in metal chelate extraction systems where the organic phase was chloroform containing dibutylphosphate, thenoyltrifluoroacetone (TTA), β-isopropyltropolone or 5,7-dichloroxine. The separation factors for this pair of ions by extraction with these four chelating ligands were determined. The distribution behavior was also studied in the adduct chelate extraction systems where the organic phase was carbon tetrachloride containing mixed ligands, TTA-tributylphosphate (TBP) or TTA-methyl isobutyl ketone (MIBK). The adduct formation constants for actinium-(III)-tris-TTA chelate with these neutral ligands were determined. Results were compared with previous results on the distribution behavior of other trivalent actinide and lanthanide ions in these systems. It was concluded that the separation of lanthanum-actinium was somewhat different from the separation of europium-americium in the same chelate extraction systems. The stabilities of the first adducts with TBP or MIBK of actinium TTA chelate were smaller than those of americium TTA chelate, but the stabilities of the second adducts showed just the reverse order. This tendency in adduct formation is the same as that observed among the lanthanum and europium adduct TTA chelates in previous work. Finally, the use of TTA-TBP mixture was recommended for the extraction of lanthanum(III) or actinium(III) at tracer concentrations based on the fact that the use of these mixed ligands resulted in much better recovery of material and better reproducibility of results than a single chelating ligand.
Hydrogenation and Hydrogenolysis. XI. The Hydrogenation of Methoxy- and Ethoxyanilines with a Ruthenium Catalyst
Authors: Nishimura Shigeo , Yoshino Hisashi
Published: July 2006

Hydrogenation of methoxy- and ethoxyanilines with a ruthenium catalyst was investigated at 80°C under the hydrogen pressure of 80–100 kg/cm2. The amount of hydrogenolysis which occurred during hydrogenation varied with solvent from 35.1% in methanol to 8.5% in t-butyl alcohol in the hydrogenation of p-methoxyaniline. With use of t-butyl alcohol as solvent, good yields of methoxy- and ethoxycyclohexylamines were obtained from corresponding alkoxyanilines. It was shown that the rate of formation of cyclohexylamine increases with increasing polarity of solvent. m-Alkoxyanilines were found to hydrogenolyze more readily than the corresponding ortho or para isomers. For the greater tendency of meta isomers toward hydrogenolysis, an explanation based on the ionic cleavage of the carbon-oxygen bond was suggested.
Photochemistry of Acetanilide. II. The Primary Processes in the Photochemical Reaction
Authors: Shizuka Haruo
Published: July 2006

The photochemical primary processes of acetanilide have been discussed on the basis of the quantum yields in various solvents, the dependences of the quantum yields on the excitation wavelength, and the emission spectra. The quantum yields of the products (o-aminoacetophenone and p-aminoacetophenone) at 2537 Å decreased greatly in polar solvents. A non-linear relationship between the quantum yield and the fraction of hydrogen-bonded acetanilide in the cyclo-hexane-ethanol solution was obtained. No variation in the quantum yield was observed upon the change of the excitation from 2537 to 2740 Å. These results indicate the occurrence of a radiationless internal conversion, S1(ππ*)←S2(ππ*). The relative fluorescence intensity in a polar solvent was larger than that in a nonpolar solvent. On the basis of these studies, it can reasonably be considered that the primary process in the photochemical reaction of acetanilide involves predissociation.
Measurement of Negative Ions Formed by Electron Impact. II. The Ionization Efficiency Curves of Negative Nitro, Oxygen Atom and Nitromethylene Ions from Nitroalkanes
Authors: Tsuda Satoru , Yokohata Akira , Kawai Michihiro
Published: July 2006

The ionization efficiency (IE) curves of NO2−, O− and CH2NO2− ions from nitroalkanes (nitro-methane, nitroethane, 1-nitropropane and 2-nitropropane) have been measured with a Hitachi RMU-6D mass spectrometer. Based on each authorized value of IP(CH3, C2H5, C3H7, O and H), D(C–NO2, C–H, C–C, NO–O and N–O), EA(NO2 and O) and the excitation energy of CH3, the respective onsets observed for the electron energies above ∼3 eV on the IE curves were suggested to be interpreted as appearance potentials of the following reactions. For NO2− ions, RNO2+e→R*+NO2−, RNO2+e→R+NO2−+e; for O− ions, RNO2+e→RNO+O−, RNO2+e→RN+O+O−, RNO2+e→RN++O+O−+e;for CH2NO2− ions, CH3NO2+e→H+ CH2NO2−+e, RNO2+e→H+R1+CH2NO2−. On the other hand, the strong peak of NO2− ions due to the dissociative electron capture process (RNO2+e→R+NO2−) was observed at the lower electoron energy. Furthermore, a value of EA(CH2NO2) was presented to be ∼0.5 eV.
Photochemistry of Acridine and Acridan. Two Isomeric Forms of Acridine Semiquinone
Authors: Kira Akira , Koizumi Masao
Published: July 2006

A transient species characterized by the absorption peaks at 350 mμ and 560 mμ has been found in the flash photolysis of acridan in both benzene and methanol solutions. This species has been proved to be different from the acridine semiquinone reported already, but has been identified as another acridine semiquinone radical on the basis of its direct conversion to acridine and also from its low reactivity to oxygen which denies the possibility of being triplet acridan. Thus it is concluded that two isomeric forms of acridine semiquinone exist. From the result of the flash photolysis of biacridan, the one reported previously has been identified definitely with a radical having a hydrogen atom attached to the nitrogen atom of acridine. Therefore, the newly discovered one is most likely a radical with a hydrogen atom attached on the 9 carbon atom of acridine.
Electron Spin Resonance Study of Radicals Formed by Abstracting Hydrogen from Amides
Authors: Yonezawa Teijiro , Noda Isao , Kawamura Takashi
Published: July 2006

Electron spin resonance (ESR) studies were made on various radicals formed from formamide, acetamide, N-methylformamide, N-methylacetamide, N,N-dimethylformamide and propionamide by hydrogen abstraction with hydroxyl radicals produced by the reaction of hydrogen peroxide and titanium trichloride in aqueous solution, using a rapid flow technique. In each case, except for formamide, various π-electron radicals were found. For formamide, N-methylformamide, and N,N-dimethylformamide, carbamoyl and its methyl substituted σ electron radicals were detected. The g factor of the σ electron radical is qualitatively discussed.
Detection of Sulfur Monoxide in the Pyrolysis of Ethylene Episulfoxide by Microwave Spectroscopy
Authors: Saito Shuji
Published: July 2006

Microwave spectroscopy has been applied to the study of the pyrolysis of ethylene episulfoxide in the vapor phase. The rotational lines of SO in the electronic ground state, 3Σ−, were observed with a good signal-to-noise ratio. The pyrolyzed sample of ethylene episulfoxide was analyzed semi-quantitatively by the use of the microwave spectra. It turned out that ethylene episulfoxide really decomposed into ethylene and sulfur monoxide. The mechanism of the thermal decomposition is discussed in detail.
The Charge-transfer Bands in the Crystal Spectra of Molecular Compounds of Tetramethylbenzidine and Those of Benzidine
Authors: Amano Takako , Kuroda Haruo , Akamatu Hideo
Published: July 2006

The polarized absorption spectra in the 280–1100 mμ region have been observed for the single crystals of eight molecular compounds which involve N,N,N′,N′-tetramethylbenzidine and benzidine as the electron donor and p-chloranil, TCNQ, 1,3,5-trinitrobenzene, and p-benzoquinone as the electron acceptor. The donor and acceptor molecules are not in the ionic states in the ground states of these molecular compounds, in spite of the low ionization potentials of tetramethylbenzidine and benzidine. The observed spectra are composed of absorption bands associated with intramolecular transitions in the constituent molecules and those associated with the charge transfer from the donor to the acceptor. It was found that the polarization of the second charge transfer band is almost perpendicular to that of the first one in the case of chloranil and TCNQ, compounds of benzidine and tetramethylbenzidine. In other cases, the first and second charge transfer bands were confirmed to be polarized nearly parallel to each other as in a usual charge transfer molecular compound.
Emission Spectrographic Analysis of Metal Solid Samples with Plasma Jet Flame. I. Application of Nitrogen Plasma Flame
Authors: Hirokawa Kichinosuke , Gotô Hidehiro
Published: July 2006

A small plasma jet burner for direct excitation of metal solid samples was developed. The optimum operating conditions are as follows; d.c. arc current about 15 A, flow rate of nitrogen tangentially introduced gas about 1.5–2 l/min, and that of atomizer gas about 3.5–4 l/min. The limit of detection of some elements were determined with solution samples. Satisfactory-calibration curves were also obtained for analyses of alloying elements in some solid form alloys.
Electronic Structure of Lone Pairs. I. Azine Compounds and Quinones
Authors: Yonezawa Teijiro , Yamabe Hiroko , Kato Hiroshi
Published: July 2006

Molecular orbital investigations of the electronic structures of lone pairs of some azine compounds and quinones are carried out by the Hückel method and the extended Hückel method for σ and π electron systems. The delocalization and the s–p mixing of lone pairs are investigated. Qualitative discussions of the splitting of the lone-pair levels and the calculated n-π* transitions of these compounds are made. It is revealed that the Hückel method, which does not include direct interactions, gives an incorrect prediction for the symmetry of the energy levels of pyridazine. After comparative discussions, it is concluded that the lone paris couple with each other directly “through-space” as well as “through-bond.”
Photo-Aryl Coupling and Related Reactions. III. The Transannular Dehydrogenation of [2.2]Metacyclophane Induced by Iodine
Authors: Sato Takeo , Wakabayashi Meiko , Hayashi Shigenari , Hata Kazuo
Published: July 2006

The ultraviolet irradiation of [2.2]metacyclophane (I) with iodine in a cyclohexane solution was shown to afford 4,5,9,10-tetrahydropyrene (II), which, on further dehydrogenation, was led to 4,5-dihydropyrene and pyrene. The transannular reaction leading to II occurred much more rapidly than the subsequent dehydrogenation reactions. Thus II was obtainable in an optimum yield of 62% by the irradiation of I in the presence of an equimolar amount of iodine and an excess of sodium bicarbonate. By ESR and UV spectral studies, 253.7 mμ light was found to be responsible for the transannular reaction.
Basicity of Dimethyl Sulfoxide in an Aqueous Solution as Measured by the Spectrophotometric Indicator Method
Authors: Wada Goro
Published: July 2006

The basic nature of dimethyl sulfoxide (DMSO) has been known in water, and so has its pKa value, which varies somewhat according to the measuring methods. In the present work, a spectrophotometric method employing thymol blue and o-nitroaniline as indicators was applied; the thermodynamical pKa° value of DMSO was determined to be −1.04 at 25°C. Since there is no dependence of pKa° upon the temperature, the proton transfer from water to DMSO in water is likely to be athermal.
Heat of Immersion of Titanium Dioxide in Water. I. The Effect of the Hydration Treatment of Titanium Dioxide
Authors: Morimoto Tetsuo , Nagao Mahiko , Omori Teiji
Published: July 2006

On anatase and rutile, three samples which differ in the extent of hydration treatment have been prepared, and the surface area, the water content, and the heat of immersion have been measured. The hydration treatment of the sample increases the water content of the sample and lowers the sintering temperature. These facts suggest that the condensation dehydration of surface hydroxyl groups from the facing surfaces of contacting particles is effective for sintering. The plot of the heat of immersion vs. the pretreatment temperature shows a maximum at about 400°C, and the heat of immersion is larger in the sample subjected to heavy hydration treatment. The heat of surface hydration, calculated from the plot of the heat of immersion vs. the water content, does not vary with the hydration treatment; it averages 25.2 and 19.0 kcal/mol H2O for anatase and rutile respectively.
The Chromium(III) Complexes with Anthranilicdiacetic Acid
Authors: Tomita Takeshi , Kyuno Eishin , Tsuchiya Ryokichi
Published: July 2006

The following chromium(III) complexes containing the anthranilicdiacetic acid (ATDA) were prepared: [Cr(atda)*(H2O)2]·3H2O (reddish-violet) (I), K[Cr(OH)(atda)(H2O)] (bluish-violet) (II), [Cr(atda)(phen)*]·3H2O (red) (III), [Cr(atda)(dipy)*·2H2O (red) (IV), [Cr(atda)(en)*]·2H2O (red) (V) and K[Cr(atda)(acac)*] (violet) (VI). From the results of electronic spectra, molar conductivities, chemical and thermal analyses and IR spectra, it was concluded that the Complexes I, II and VI belong to the [CrO5N], and III, IV and V belong to the [CrO3N3] type. ATDA in all these complexes obtained was found to behave only as a quadridentate ligand. The values of the effective magnetic moments were found to be 3.7–3.9 B. M., nearly equal to the spin-only values of the tervalent chromium. \oindent(* atda, phen, dipy, en and, acac are the basic forms of anthranilic acid, o-phenanthroline, 2,2′-dipyridyl, ethylenediamine and acetylacetone respectively.
Circular Dichroism of Chromium(III) Complexes. I. l-Tartrato Complexes. Their Stereospecific Formation and Spin-forbidden Absorption Bands
Authors: Kaizaki Sumio , Hidaka Jinsai , Shimura Yoichi
Published: July 2006

Two novel mixed chromium (III) complexes containing l-tartrates and 2,2′-dipyridyl or 1,10-phenanthroline have been prepared, and their electronic absorption and circular dichroism spectra and the rotatory dispersion have been measured in the region of near-infrared to ultraviolet. From the construction of molecular models and from the comparison of the CD bands of the present complexes with those of the resolved oxalato complexes, (−)546-K[Cr(ox)2(dip)]·3H2O and (−)546-K[Cr(ox)2(phen)]·4H2O, it has been concluded that the present complexes have a binuclear structure in which two Cr(III) ions are bridged by two tetradentate l-tartrato ligands and that the absolute configuration of the binuclear complexes is Λ(C2)-Λ(C2). Their formation is completely stereospecific and their formulae are represented by Ba[Cr2(l-tart2H)(dip)2]2·9H2O and NH4[Cr2(l-tart2H)(phen)2]·6.5H2O. The absolute configurations of several complexes which commonly belong to a general type, cis-[Cr(O)4(N)2] have been determined on the basis of circular dichroism studies of the present binuclear complexes. The circular dichroism in the spin-forbidden absorption band region have also been measured and discussed.
The Three-dimensional Structure of Macromolecules. I. The Conformation of Ethylene Polymers by the Monte Carlo Method
Authors: Suzuki Keizo , Nakata Yoshiro
Published: July 2006

The Monte Carlo method is employed on a high-speed digital computer in order to generate non-intersecting random chains simulating polymer molecules. For this purpose the GT-model of polyethylene is used. Suitable potential functions are used to calculate the energy and the probability of each chain conformation thus generated. The nonbonded-interaction energy is calculated by the Lennard-Jones “6–12” potential function. The average dimensions are then calculated by using this energy. It is suggested that the hydrogen atoms contribute largely to the statistical properties of the ethylene polymers.
Syntheses and Properties of Metal Chelates of Ethanediylidenetetrathiotetraacetic Acid (ETTA) and Some Other Thioglycolic Acid Derivatives
Authors: Ouchi Akira , Ohashi Yayoi , Takeuchi Toshio , Yoshino Yukichi
Published: July 2006

Some new metal chelate compounds of ethanediylidenetetrathiotetraacetic acid (H4ETTA), Co2L·5H2O, Cu2L·4H2O, Zn2L·3H2O, Ni2L·6H2O, and FeHL·3.5H2O, where H4L is H4ETTA, were obtained. The infrared spectra and other properties of these compounds were compared with those of the metal complexes of other thioglycolic acid derivatives, some of which are also new compounds. Judging from the wave numbers of the stretching bands, the carboxyl group of these complexes can be said to be rather ionic. Though the bond is not very strong, thioglycolic acid derivatives seem to bond with the central metal ion with both the sulfur atom and the carboxyl group.
A New Synthesis of Aziridines from β-Amino Alcohols with Triphenylphosphine Dibromide
Authors: Okada Itaru , Ichimura Kunihiro , Sudo Rokuro
Published: July 2006

The reaction of β-amino alcohols with triphenylphosphine dibromide was found to give the corresponding aziridines in good yields. The reaction opened a new route to the synthesis of aziridine compounds which seems to be more convenient than the Gabriel and Wenker methods. In the ring closure of ephedrine, a Walden inversion was observed. A possible mechanism is suggested.
Charge-Transfer Interaction in Linear Chain Molecular Crystals
Authors: Sakata Tadayoshi , Nagakura Saburo
Published: July 2006

The charge-transfer interaction is investigated theoretically for linear chain systems in molecular crystals. The charge-transfer excitation energy is shown to diverge in crystals by the usual configuration interaction method considering only one-molecule excitation. In order to overcome this difficulty, the second quantized Hamiltonian is solved with the Bose approximation for the charge-transfer exciton. Consequently, reasonable results are obtained for the stabilization of the ground state due to the contribution of many virtual excitons, for the electric dipole moment of the ground state, and for the transition moment of a charge-transfer excitation. The results correspond well to those by Mulliken’s theory for an electron donor-acceptor pair. The second quantization model is also applied in the extended form to crystals of charge-transfer complexes and ionic radicals of complex stoichiometry. The lower excited states in these crystals are understood as the coupled ones of the one-site and two-site charge-transfer configurations.
Studies on the Separation of Rare Earths. Determination of the Optimum Concentration of Ligand Ion Used in Electromigration
Authors: Ohyoshi Emiko
Published: July 2006

An attempt to determine the optimum concentration of ligand ion for the separation of adjacent pairs of rare earth elements by electromigration was made using the method employed for the determination of the stability constant of complex. To examine the theory, separation of lanthanum and cerium, and cerium and praseodymium was carried out using α-hydroxyisobutyric acid as a complexing agent. From the results, factors necessary for the separation of all kinds of rare earth elements were discussed.
Studies of Phenylxanthyl and Its Analogues by Electron Spin Resonance
Authors: Maruyama Kazuhiro , Yoshida Masaharu , Murakami Katsuya
Published: July 2006

Phenylxanthyl, phenylthioxanthyl, phenylselenoxanthyl, 9-phenylfluorenyl, dioxadehydrocoranthryl, and their derivatives were studied by the electron spin resonance (ESR) technique, and the odd-electron distribution in the radicals was examined. From the results, the angle between the plane of the phenyl group and the plane of the rest of the molecule was estimated at about 63°. Since these radicals are in equilibria with their dimers, heat of reaction in the system was also determined on two of them. Some discussion of the correlation between the heat of reaction and the molecular shape was undertaken.
Deamination of Methylenecyclopropylcarbinylamine. The Formation of a Vinyl Cation by Carbon-Carbon Bond Cleavage
Authors: Nishimura Akio , Ohta Masaki , Kato Hiroshi
Published: July 2006

The deamination of methylenecyclopropylcarbinylamine, prepared from ethyl methylenecyclopropanecarboxylate via the corresponding amide, gave acetylcyclopropane, methylenecyclopropylcarbinol, and 3-methylenecyclobutanol. On the basis of these results and the deuterium distribution of the deamination products of methylenecyclopropylcarbinylamine-α,α-d2, the homoallylic (III) and cyclopropylvinyl (VIII) cations are proposed as intermediates.
Charge Transfer Interaction between 2,3-Dichloro-5,6-dicyano-p-benzoquinone and Substituted Benzenes
Authors: Srivastava R D , Prasad G
Published: July 2006

Charge transfer complexes between 2,3-dichloro-5,6-dicyano-p-benzoquinone and various methyl and phenyl substituted benzenes have been studied. The spectral characteristics and equilibrium constants of o-, m-, and p-xylenes and those of o-, m-, and p- terphenyls are reported. The results have been interpreted in terms of Mulliken’s charge transfer theory. From the spectral data, the electron affinity of 2,3-dichloro-5,6-dicyano-p-benzoquinone has been estimated to be 1.974 eV. The energy of the first CT band has been found to be related to the ionization potential of the donors by the expression hϑCT=0.7ID−3.86.
2-Substituted Imino-1,3-dithiolanes. Their Thermal Ring-isomerizations and Reactions with Epoxides
Authors: Ueno Yoshio , Nakai Takeshi , Okawara Makoto
Published: July 2006

Thermal ring-isomerization and reactions with epoxides of 2-substituted imino-1,3-dithiolanes (I) were studied. The methylimino (Ia) and ethylimino derivatives (Ib) were found to be ringisomerized to the corresponding 3-alkyl-1,3-thiazolidine-2-thione (V) at about 200°C, while the phenylimino compound (Ic) was not isomerized even under more drastic conditions. The influence of various additives including Lewis acids was also examined. In contrast to the oxygen analog of I, these imino compounds were not polymerized with Lewis acids, and catalysis of any additives on isomerization was not observed. The possibility that I thermally dissociated into methyl isothiocyanate and ethylene sulfide followed by their recombination to V would be excluded by the observation that the reaction of alkyl isothiocyanate with ethylene sulfide at 150°C afforded I in good yield. Reactions of I with epoxides were carried out regarding the isomerization mechanism. All these imino compounds reacted with epoxides to give the 2-oxazolidone derivatives (III) in good yield. Mechanisms of the ring-isomerization and formation of III have been suggested, and the difference in reactivity between I and its oxygen analog has been discussed.
Determination of the Molecular Structures of AsF3 and AsCl3 by Gas Electron Diffraction
Authors: Konaka Shigehiro , Kimura Masao
Published: July 2006

The thermal-average distances and mean amplitudes of AsCl3 and AsF3 have been determined by gas electron diffraction. The sources of experimental errors have been discussed in detail. The observed molecular parameters are rg(As–Cl)=2.1621±0.0033 Å, θg(ClAsCl)=98°34′±34′, l(As–Cl)=0.0470±0.0024 Å, l(Cl–Cl)=0.0945±0.0063 Å, rg(As–F)=1.7089±0.0016 Å, θg(FAsF)=95°53′±22′, l(As–F)=0.0433±0.0022 Å, and l(F–F)=0.0689±0.0044 Å. The results have been compared with the structures of other trihalides of the Vb-group elements.
Polarography of Halides in Dimethylformamide. II. The Iodide Ion, the Triiodomercurate Ion, and Mercuric Iodide
Authors: Matsui Yoshihisa , Kurosaki Yukio , Date Yoshio
Published: July 2006

The polarographic behavior of the iodide ion, the triiodomercurate ion, and mercuric iodide at the dropping mercury electrode was investigated in dimethylformamide, using d.c. polarography, controlled potential electrolysis, and oscillographic polarography with a multi-triangular voltage sweep. The iodide ion gives two well-defined anodic waves: the first wave corresponds to the reversible oxidation of mercury to the triiodomercurate ion, and the second, to the reversible oxidation of mercury to mercuric iodide. A maximum arises on the reduction wave of the triiodomercurate ion, but it is suppressed by the addition of a small amount of polyvinyl chloride. The oscillographic polarograms and electrocapillary curves suggested that the iodide ion, like the triiodomercurate ion and mercuric iodide, is strongly adsorbed on the dropping mercury electrode. The maximum on the wave due to the reduction of the triiodomercurate ion to mercury and the iodide ion was ascribed to the convection of the mercury drop, which was itself probably caused by the abrupt desorption of the iodide ion formed successively with an increase in the negative potentials. The adsorption phenomena of the corresponding bromides and chlorides are also discussed.