bluuebunny/crossref_metadata_2025 huggingface dataset:
Alkylation of Phenols. II. The Selective Formation of Thymol from m-Cresol and Propylene with a γ-Alumina Catalyst
Authors: Nitta Masahiro , Aomura Kazuo , Yamaguchi Katsumi
Published: July 2006

The alkylation of m-cresol with propylene was carried out over a γ-alumina catalyst in a flow system under atmospheric pressure. It was found that the composition of the thymol mixture thus obtained was greatly ortho-rich. It was also observed that the catalytic activity varied with the temperature and the atmosphere for the calcination of the catalyst, whereas the selectivity for thymol formation was almost constant at about 90% at the reaction temperature of 250 °C. It has been established that thymol can be obtained selectively by vaporphase alkylation over a commercial γ-alumina catalyst under appropriate reaction conditions. Furthermore, the active sites of γ-alumina for this reaction were investigated by the poisoning technique with acids and bases. It was suggested that, for the alkylation, the Lewis-acid sites (surface aluminum) and the adjacent acid sites (surface hydroxyl) are necessary. The mechanism of the alkylation on those sites is also discussed.
Reactions in the Adsorbed Layer: Hydrogenation of Acetone on Nickel Catalysts
Authors: Miyata Hisashi , Minobe Mitsuhiko , Kubokawa Yutaka
Published: July 2006

The hydrogenation of acetone adsorbed and the dehydrogenation of isopropanol adsorbed on silica-supported nickel catalyst have been studied by following the changes of hydrogen pressure and the reaction products as well as the IR spectra of adsorbed species. It was found that the formation of isopropanol proceeds via a precursor composed of acetone and hydrogen. The activation energies of hydrogenation of acetone adsorbed and of dehydrogenation of isopropanol adsorbed were 11–13 and 4–8 kcal/mol, respectively. The activation energy of the desorption was 13 kcal/mol for isopropanol and 19 kcal/mol for acetone. From the results the potential energy change during the hydrogenation of acetone was determined.
The Magnetic Properties of Verdazyl Free Radicals. VI. ESR Studies of Pairs and Triadst of the Symmetrical Triphenylverdazyl Radical in the 1,3,5-Triphenylbenzene Matrix
Authors: Azuma Nagao , Ohya-Nishiguchi Hiroaki , Yamauchi Jun , Mukai Kazuo , Deguchi Yasuo
Published: July 2006

Single-crystal ESR studies have been carried out on symmetrical triphenylverdazyl (TPV) doped in a diamagnetic 1,3,5-triphenylbenzene (TPB) crystal at room temperature. There have appeared seven pairs of fine-structure absorptions in addition to the hyperfine splittings. Three out of the seven pairs have been assigned as zero-field splittings due to radical pairs, while the other three pairs have been identified as from radical triads. The six fine structure tensors have been determined through the angular variation of the resonance-field separations. The structures of the pairs and triads of TPV were discussed on the basis of the fine structure tensors, the crystal structures of TPB and TPV, and the spin distribution in the radical molecule, assuming that the unit cell of the mixed crystal with the radical concentration of less than 11.1% is identical with that of the host crystal, TPB. Within the limits of the X-ray examination, this assumption was found to be reliable. It was found that the molecular planes in each species are almost parallel to the bc-plane and that all the C-phenyl rings lie in the c-direction.
Electronic Spectra of Perylene Crystals
Authors: Tanaka Jiro , Kishi Tohru , Tanaka Masashi
Published: July 2006

The electronic absorption and emission spectra of α and β forms of perylene have been investigated. The lowtemperature spectra have been studied with the (001) plane, and adetailed vibrational analysis is presented. The reflection measurements with the (001) plane and the (110)or (1\bar10) plane are carried out, and the Kramers-Kronig transformation is carried out in order to obtain the absorption coefficient. The results present reasonable evidence for the existence of the intermolccular CT transition in the 27000 cm−1 region. The emission spectra at 4.2 K present several novel features of the mechanism of a monomer-like emission of the α-crystal.
Photochemical Reaction of Halo-1,3,5-triazines: Photo-triazinylation
Authors: Yamada Hideo , Shizuka Haruo , Sekiguchi Shizen , Matsui Kohji
Published: July 2006

Chloro-s-triazines or broma-s-triazines containing halogen and/or methoxy subsituents in the s-triazine nucleus gave the corresponding phenyl-s-triazines upon irradiation at 2537Å in the benzene.
Reaction of Chlorohydrocarbons. VI. Co-pyrolysis of Chloroethanes and Methanol on Activated Alumina
Authors: Shinoda Kiyonori
Published: July 2006

Co-pyrolysis of chloroethanes and methanol on activated alumina was carried out in order to elucidate the reaction mechanism. The reaction rate was of first order in chloroethanes in the presence of excess methanol. A linear free energy relationship was found to exist between the reactivities of chloroethanes (at 230°C) and Taft’s σ* constants, ρ* values for reactions of RCH3, RCH2Cl and RCHCl2 series were 0.24, 0.45 and 0.70, respectively. It could be assumed that a β-hydrogen of chloroethanes was abstracted by the nucleophilic attack of methanol, chlorine being removed at the same time. E2 reaction seems to dominate in co-pyrolysis of chloroethanes and methanol on activated alumina.
Reactions of Aryliminotriphenylphosphoranes with Sulfenes
Authors: Kawashima Takayuki , Inamoto Naoki
Published: July 2006

Aryliminotriphenylphosphoranes reacted with methanesulfonyl, ethanesulfonyl and α-toluenesulfonyl chlorides in the presence of triethylamine to give 1 : 2 adducts [α-(N-alkanesulfonyl-N-arylsulfamoyl)alkylidenephosphoranes] and the decomposition products, instead of 1 : 1 adducts [α-(N-arylsulfamoyl)alkylidenephosphoranes). They were obtained under ice-cooling, the structure being of betaine type. In the case of methanesulfonyl chloride, isomeric 1 : 2 adduct [α-(N-arylsulfamoyl)methanesulfonylmethylenephosphorane] was also obtained. 2-Propanesulfonyl chloride gave N-triphenylphosphonio-N-arylsulfamate instead of expected adduct. In the absence of triethylamine, α-(N-arylsulfamoyl) alkyltriphenylphosphonium chlorides were obtained in good yields. Possible mechanisms of these reactions have been discussed.
Metal Phosphinylides and Phosphinothioylides. I. Formation of Metal Diphenylphosphinylides and Diphenylphosphinothioylides and the Reactions with Some Organic Halides and Aldehydes
Authors: Emoto Tateki , Gomi Hideyuki , Yoshifuji Masaaki , Okazaki Renji , Inamoto Naoki
Published: July 2006

Lithium diphenylphosphinylide or diphenylphosphinothioylide ([Ph2PX]Li; X=O, S), prepared from diphenylphosphine oxide or sulfide and n-butyllithium, reacted with methyl iodide, acetaldehyde and benzaldehyde to give the corresponding phosphine oxides or sulfides in good yields, indicating the formation of C–P bond. Formation of [Ph2PS]MgCl from diphenylphosphinothioyl chloride (1) and magnesium was confirmed by the similar reactions. When 1 was allowed to react with magnesium or sodium for a long time, diphenylphosphides ([Ph2P]M) were produced by desulfurization, together with [Ph2PS]M (M=MgCl, Na). Reaction of 1 with [Ph2PS]M gave tetraphenyldiphosphine disulfide through formation of P-P bond, while diphenylphosphinyl chloride and [Ph2PO]M reacted through formation of P–O bond. The difference has been explained by soft-hard-acid-base concept.
Metal Phosphinylides and Phosphinothioylides. II. Effects of Metals on the Reactions of [Ph2PX]M with Benzaldehyde and p-Benzoquinone
Authors: Goda Koshiro , Gomi Hideyuki , Yoshifuji Masaaki , Inamoto Naoki
Published: July 2006

Reactions of [Ph2PO]M with benzaldehyde gave benzyl benzoate and benzyldiphenylphosphine oxide (3) in the case of M=Na, 3, α-hydroxybenzyldiphenylphosphine oxide, benzyl alcohol, benzoin and benzil in the case of M=MgCl, and 3 in the case of M=ZnCl. Reactions of [Ph2PX]M with p-benzoquinone gave 2,5-dihydroxyphenyldiphenylphosphine oxide or sulfide and p-hydroxyphenyl diphenylphosphinate in the cases X=O, S and M=Li, MgCl, Al, and 1,4-phenylene bis(diphenylphosphinate) or bis(diphenylphosphinothioate) in the cases X=O, S and M=FeCl. The reaction mechanisms have been discussed.
Anomeric Effect in Sulfur Heterocycles Carrying Sulfur Substituents
Authors: Oki Michinori , Sugawara Tadashi , Iwamura Hiizu
Published: July 2006

Conformational analysis of 1,3,5-trithiane derivatives with sulfur-substituents was carried out with the aid of PMR spectra at various temperatures. 2-Phenylthio-1,3,5-trithiane exhibited the strong anomeric effect whereas 2-phenylthiothiane the moderate. This enhanced anomeric effect in trithiane derivatives was attributed to both the stabilization of the axial form and the destabilization of the equatorial form. cis-2,4-Bis(phenylthio)-1,3,5-trithiane was found to possess a diaxial conformation to a fair extent in support of the presence of the strong anomeric effect. Equilibration between cis and trans forms of 2,4-bis(phenylthio)-1,3,5-trithiane was carried out to show that the trans form was more stable than the cis. The barrier to inversion of trans-2,4-bis(phenylthio)-1,3,5-trithiane was obtained as ca. 11 kcal/mol.
Die Rolle des Oxydationseffekts bei der Lithentwicklung
Authors: Suga Tsuneo
Published: July 2006

Als Fortsetzung früherer Mitteilungen, in welchen der Autor auf die oxydative Wirkung der Oxydationsprodukte des Hydrochinons bei der Lithentwicklung hinwies, wurde hier der Oxydationseffekt eingehender untersucht und der Mechanismus der Lithentwicklung diskutiert, obwohl einige Arbeiten keinen Oxydationseffekt vertreten. Die Lithentwicklung hat eine beträchtliche Induktionsperiode, in der man keine Schwärzung bemerken kann. Durch physikalische Entwicklung, die der chemischen Entwicklung und dem Fixieren nachfolgte, bemerkte man eine sichtbare Schwärzung. Diese Versuchsmethode führte zu folgenden Ergebnissen. Während der Induktionsperiode konnte man das Wachstum von Entwicklungskeimen experimentell finden. Der Oxydationseffekt angesammelter Oxydationsprodukte auf die Entwicklungskeime wurde im Entwicklungsverlauf nach der Induktionsperiode als wirksam betrachtet. Während der Induktionsperiode wurde aber eine Oxydation der Entwicklungskeime durch die diffundierenden Oxydationsprodukte als Saumeffekt beobachtet. Durch die Feststellung des Oxydationseffekts ist die Folgerung über den Mechanismus der Lithentwicklung die gleiche wie in früheren Arbeiten, kann aber ausführlicher beschrieben werden.
The Methylation of Phenol and the Decomposition of Methanol on ZnO–Fe2O3 Catalyst
Authors: Kotanigawa Takeshi
Published: July 2006

As a result of a series of studies, ZnO–Fe2O3 catalysts have been shown to promote the selective methylation (k1) of phenol at the ortho position and also to promote the decomposition of methanol (k2). The activation energies were determined to be 22±2 kcal/mol for the methylation and 27 ±3 kcal/mol for the decomposition. The selectivity factor (S=k1⁄k2) of the simultaneous reaction was determined for five types of catalysts in order to estimate the most favorable catalyst for the methylation. The selectivity factor of these catalysts decrease with the rise in the calcination temperature. For example, the S on the catalysts calcined at 500 °C is approximately at unity but the S on the catalysts calcined at 800 °C is at about 0.4. These results suggest that the calcination using the present catalysts should be controlled at a low temperature.
The Formation and Collapse of Mixed Monolayer of Triolein and Tricaprylin
Authors: Nakagaki Masayuki , Funasaki Noriaki
Published: July 2006

The surface pressure-area curves of mixed monolayers of triolein and tricaprylin and the equilibrium spreading pressures of these liquid mixtures were measured at 25 °C. The surface pressures of the monolayers of the pure components, triolein and tricaprylin, did not vary when the monolayer was compressed below its collapse area, but the surface pressure of their mixed monolayers increased with the compression; the surface pressure at a zero area agreed well with the value of the equilibrium spreading pressure. From the two curves, the one representing the relation between the collapse pressure and the composition of the mixed monolayer, and the other representing the relation between the equilibrium spreading pressure and the composition of the liquid mixture, the compositions of the mixed monolayer and the liquid mixture coexisting in the equilibrium were obtained. Consequently, it was found that the component whose collapse pressure was lower was richer in the liquid mixture than in the mixed monolayer, while the other component, whose collapse pressure was higher, was poorer in the liquid mixture than in the mixed monolayer. It was concluded, on the basis of the phase rule and thermodynamics for a plane interface, that triolein and tricaprylin form a regular mixture in the monolayer as well as in a liquid.
Solvent Extraction Studies of the Hydrolysis of Antimony(III) in Tracer Concentrations
Authors: Shoji Hitoshi , Mabughi Hisao , Saito Nobufusa
Published: July 2006

The hydrolysis of antimony(III) ions was investigated through solvent extraction with dithizone–carbon tetrachloride solutions. In a 3 M (H, Na)ClO4 solution, a tracer concentration of antimony(III) (<10−8M) was found in the form of a monovalent cation, Sb(OH)2+ or SbO+, and a neutral species, Sb(OH)3 or SbO(OH). The former is predominant in strongly acidic media, while the latter becomes abundant in the weakly acidicto-neutral region. One of the constants of successive hydrolysis, K1=[Sb(OH)2+][Sb(OH)3]−1[H+]]−1, was calculated from the distribution ratios, giving the result: logK1=1.236±0.06. The chemical composition of the extracted species was estimated to be Sb(HDz)3.
Intramolecular Hydrogen Bonding and Conformations of α,α-Dialkyl-and α-Alkyl-o-methoxybenzyl Alcohols
Authors: Yamashita Akihiko , Hara Katsuo , Aizawa Shigeko , Hirota Minoru
Published: July 2006

The stable conformations of α-alkyl- and α,α-dialkyl-o-methoxybenzyl alcohols were deduced by measurement of their infrared and PMR spectra. Population of these conformations was estimated from the intensities of the O–H stretching bands of the free and the hydrogen-bonded species. The O–H chemical shifts at infinite dilution (δOH∞) of the free and the hydrogen-bonded species were determined by plotting the δOH∞ values against population obtained from the infrared spectra. An anomalous behavior was observed with the α-alkyl-α-t-butyl alcohols, which might be due to a buttressing effect.
Preparation of 1,7-Disubstituted Indan Derivatives and Their Application to the Synthesis of Tricyclic Heterocyclic Compounds
Authors: Sakane Kazuo , Oda Shinichi , Haruki Eiichi , Otsuji Yoshio , Imoto Eiji
Published: July 2006

The Birch reduction of acenaphthene (1) followed by treatment of the reduction product with sodium ethoxide gave 2a,3-dihydroacenaphthene (3). The oxidation of 3 with hydrogen peroxide gave 2a,3,4,5-tetrahydroacenaphthene-4,5-diol (5). Further oxidation of 5 afforded various 1,7-disubstituted indan derivatives including 7-carboxyindan-1 -acetic acid (7). Two tricyclic N-heterocyclic compounds, 3,3a-dihydrocyclopent[de]quinolin-2(1H)-one (13) and 3,3a-dihydrocydopent[de]isoquinolin-1(2H)-one (17), were synthesized from 7.
A New Synthesis of α,β-Unsaturated Carboxylic Esters. The Condensation of Ethyl Lithiotrimethylsilylacetate with Carbonyl Compounds
Authors: Taguchi Hiroaki , Shimoji Katsuichi , Yamamoto Hisashi , Nozaki Hitosi
Published: July 2006

The key step of the title synthesis involves the conversion of ethyl trimethylsilylacetate to the corresponding enolate, 1, by treatment with lithium dicyclohexylamide in tetrahydrofuran at −78 °C. The condensation of 1 with aldehydes and ketones proceeds smoothly to afford the desired two carbon homologated unsaturated esters in excellent yields. The new process is extended with success to readily-enolizable carbonyl compounds and also to chalcone, which gives no trace of the Michael adduct in the present reaction.
Infrared Absorption Intensities of trans- and cis-Dichloroethylene
Authors: Tanabe Kazutoshi , Saëki Shinnosuke
Published: July 2006

Infrared absorption intensities of trans- and cis-dichloroethylene were measured in the vapor phase, and interpreted in terms of intensity parameters common to the isomers. In order to obtain L matrices, force constants common to the isomers were determined so as to attain the best fit between the observed and calculated frequencies of CHCl=CHCl, CDCl=CDCl and CHCl=CDCl. Using the L matrices thus obtained, intensity parameters were determined so as to attain the best fit between the observed and calculated intensities of CHCl=CHCl. As a result, the observed frequencies and intensities were satisfactorily represented in terms of the force constants and the intensity parameters common to the isomers.
A Study of the Inosine–Sodium Hydroxide–Water and Inosine–Potassium Hydroxide–Water Systems
Authors: Suzuki Yoshihisa , Toki Tadao
Published: July 2006

Solubility data have been obtained for the inosine–NaOH–H2O and inosine–KOH–H2O systems at 30 °C. Two different solid phases of the potassium salt of inosine (C10H11N4O5·K·H2O and C10H11.5N4O5·0.5 K·0.5 H2O) were found in the latter system, while only one solid phase of the sodium salt of inosine (C10H11N4O5·Na·2.5 H2O) was found in the former system. The hemi-potassium salt of inosine is incongruent and is decomposed by pure water, whereas the mono-alkaline-metal salts are stable. The solubilities of the two mono-alkaline-metal salts of inosine in water were determined at 0–50 °C and formulated as follows:

Na-salt, logS & = 0.01359·t+0.3997

K-salt, logS & = 0.00733·t+1.6513

where S represents the gram weight of the anhydrous salt per 100 g of water. The X-ray powder diffraction data of the above three salts are given.
Photoelectron Spectra of Substituted Benzenes
Authors: Kobayashi Tsunetoshi , Nagakura Saburo
Published: July 2006

Photoelectron spectra were measured in the region between 6 and 21 eV for aniline, N,N-dimethylaniline, phenol, anisole, benzonitrile, acetophenone, nitrobenzene, and their methyl derivatives. The observed spectra were interpreted in terms of their MO’s obtained by the CNDO/2 and EHMO methods, the methyl-substituent effect and the steric hindrance effect being considered. Both effects are essential for the reliable assignment of the observed photoelectron spectra. We found a general tendency that the interaction of the doubly degenerate highest occupied orbitals (e1g) of the benzene ring with the highest occupied orbital of a substituent group is important for the interpretation of the observed lower energy (7∼12 eV) bands. The only exceptional case is the nitrobenzenes in which the lowest vacant orbital of the substituent group is rather close to the highest occupied orbitals of the benzene ring and the interaction between them is important. The effects of the substituent groups upon the observed photoelectron spectra are classified into four types.
Formation of Long-Lived Highly-Excited States of H, C, and N Atoms by Low-Energy Electron Impact on CH3CN
Authors: Shibata Takemasa , Fukuyama Tsutomu , Kuchitsu Kozo
Published: July 2006

Long-lived excited states of hydrogen, carbon and nitrogen atoms (H**, C** and N**) produced by the electron bombardment of CH3CN in the energy range from 20 to 100 eV were detected as H+, C+ and N+ ions as a result of collisions with H2O. The appearance potential of H+ was observed to be about 3 eV lower than the threshold energy for He+ formed from He** with H2O (about 24.6eV). The C+ threshold energy was about the same as that for He+, while that for N+ appeared to be a few eV higher. This suggests that the H** species is mainly responsible for the formation of CH3CN− due to the electron bombardment of CH3CN observed by Sugiura and Arakawa, at least in the energy region below the He** threshold energy.
The Chemistry of α, N-Hydroxyamino Acids
Authors: Ahmad Afzal
Published: July 2006

α,N-Hydroxyamino acids have been shown to be unstable compounds. They disproportionate into corresponding α-amino acids and α-oximino acids below pH 7. This has been suggested to be a general reaction in all mono-substituted hydroxylamines.
The Basic Compound Produced in the γ-Radiolysis of Liquid Nitrogen Containing Hydrocarbons
Authors: Ishizaki Kaname , Sato Shin
Published: July 2006

The G-values of the basic compounds produced in the γ-radilysis of liquid nitrogen containing hydrocarbons have been measured by Conway’s method. The concentration dependence of the G-values suggests that the basic compounds observed are the products of the reaction between nitrogen atoms and the hydrocarbon radicals eventually formed in the system.
ESR Spectra of Radicals during Photolysis of Chloranil in Solutions
Authors: Yoshida Hiroshi , Kambara Yoshihiko , Rånby Bengt
Published: July 2006

ESR spectra were recorded during photolysis of chloranil in 2-propanol, ethanol, methanol and benzene at room temperature. The spectra observed from solution in alcohols are identified as due to neutral seqmiuinone radical. It is also suggested that excited chloranil abstracts a hydrogen from benzene.
Phase Diagrams of the Binary Systems of Some Metal β-Diketonates
Authors: Yoshida Isao , Kobayashi Hiroshi , Ueno Keihei
Published: July 2006

Phase diagrams of the binary systems consisting of some unchanged β-diketone chelates were determined. A combination of the chelate compounds which had the same coordination structures gave a mixed crystal system, and that of different coordination structures gave a eutectic system.
Electron Pairing Interaction and Electronic Spectra of Linear Polyene
Authors: Basu Sadhan
Published: July 2006

Assuming the pairing interaction which arises in Hartree-Fock-Bogolyubov formulation in manyelectron system, to be due to attraction between two electrons of opposite spin it has been shown that the longest wavelength singlet transition in linear polyenes will show convergence limit while the corresponding triplet transition will not.
Photochemistry of Acetophenone and Acetaldehyde in Ether Solvent —Formation of Diastereoisomeric Alcohols
Authors: Tokuda Masao , Hasegawa Miki , Suzuki Akira , Itoh Mitsuomi
Published: July 2006

Irradiation of acetophenone and acetaldehyde in tetrahydrofuran or diethyl ether gave the following diastereoisomeric alcohols, 1-phenyl-1-(2-tetrahydrofuryl)ethanol, 1-(2-tetrahydrofuryl)ethanol, 2-phenyl-3-ethoxy-2-butanol and 3-ethoxy-2-butanol.
ESR Study of γ-Irradiated Silk : Effect of Oxygen
Authors: Yoshioka Hisashi , Koide Naoto , Higashide Fukuji
Published: July 2006

The ESR spectra of silk γ-irradiated in a vacuum showed a doublet at room temperature and at −196 °C. The doublet turns to a singlet at g=2.006 by admission of O2. This is explained in terms of the formation of peroxide radicals.
The Circular Dichroism and Magnetic Circular Dichroism Spectra of Bis(stilbenediamine) nickel(II) Complexes
Authors: Arakawa Sumio , Nozawa Tsunenori , Hatano Masahiro
Published: July 2006

The temperature dependence of the absorption and circular dichroism spectra for [Ni((+)-stien)2](ClO4)2 is indicative of the equilibrium between the square planar (yellow) and tetragonal (violet) species in acetone solutions. On the other hand, the square planar species is predominant in a methanol solution, even at room temperature, in the case of [Ni(meso-stien)2](ClO4)2. The Cl− as a counter anion favored an equilibrium slightly displaced to the tetragonal species. The analysis of the CD and MCD bands suggests an ordering of the d-orbital energy levels of dx2–y2>>dz2>dxz,dyz>dxy.
The Photochemical Reaction of Benzofuran Derivatives with Benzophenone or Benzaldehyde
Authors: Kawase Yoshiyuki , Yamaguchi Seiji , Ochiai Hirokazu , Horita Hisanori
Published: July 2006

The photochemical reaction of 2-methyl-, 2,3-dimethyl-, 2,3-butano-, and 2-hydroxymethyl-benzofuran with benzophenone gave the corresponding oxetanes in yields higher than, or comparable to, those in the case of unsubstituted benzofuran, but in lower yields than in the cases of 3-methyl- and 2-isopropyl-benzofuran. The oxetanes were also produced by the reaction of 2-methyl-, 2,3-dimethyl-, and 2,3-butano-benzofuran with benzaldehyde, but these yields were not so high because of their instability. The reaction of 2-methoxycarbonyl-and 2-cyano-benzofuran with benzophenone or benzaldehyde gave dimers of the benzofurans, as in the case of 2-phenylbenzofuran.
Superacids and Their Derivatives. VI. Kinetics of the Cationic Ring-Opening Polymerization of Tetrahydrofuran Initiated by Ethyl 2,4,6-Trinitrobenzenesulfonate
Authors: Kobayashi Shiro , Nakagawa Tamotsu , Danda Hidenori , Saegusa Takeo
Published: July 2006

Ethyl 2,4,6-trinitrobenzenesulfonate (“trinitate”, EtOTn) was found to induce the ring-opening polymerization of tetrahydrofuran (THF). Kinetic studies of the THF polymerization by EtOTn initiator were carried out in CH2Cl2 solution by NMR spectroscopy. The instantaneous concentrations of the counteranion of the propagating oxonium species (1) and monomer were directly determined at the same time by the NMR measurement. The rate constants of initiation (ki) and propagation (kp(i)) due to 1 were obtained. Upon the view of kp(i) values with various initiators, it was concluded that the kp(i) values are changed significantly depending on the nature of the counteranion.
Hetera-p-carbophanes. IV. The Effect of Rigidity on the Chemical Shifts of Protons in Ansa Chains and Barriers to Rotation of Dioxadioxo[n]paracyclophanes
Authors: Sakamoto Kazuhiko , Oki Michinori
Published: July 2006

A series of dioxadioxo[n]paracyclophanes with or without methyl groups at the benzene ring were prepared and their PMR spectra compared with those of open-chain analogs as well as with those of paracyclophanes. Rigidity of the ansa chain was found to be an important factor in determining the chemical shifts of the ansa chain protons in addition to the ring current effect. Measurement of the PMR spectra at various temperatures revealed that the chemical shifts of the benzylic protons drifted to a small extent according to temperatures and the phenomenon was attributed to the change of solvation. Barriers to rotation of the aromatic rings in 615 and 616 were obtained as 23.3 and 11.0 kcal/mol, respectively. The barrier was discussed from the stand point of rigidity of the ansa chain.
The Crystal and Molecular Strucure of Arabinofuranosyladenine Hydrochloride
Authors: Hata Tadashi , Sato Sadao , Kaneko Masakatsu , Shimizu Bunji , Tamura Chihiro
Published: July 2006

Crystals of arabinofuranosyladenine hydrochloride are monoclinic, space group P21 with a=6.47, b=15.56, c=6.87 Å, and β=111.6°. Intensity data were collected on a four-circle diffractometer with Mo-Kα radiation. The structure was solved by means of Patterson and Fourier methods and refined using block-diagonal least-squares technique. The final R-factor for 1681 observed reflections is 4.5%. The sugar conformation is C3′-endo and the C(5′)–O(5′) bond is gauche to both C(4′)–O(1′) and C(4′)–C(3′). The torsional angle about the glycosidic C–N bond is anti, with χCN=29.3°. The hydrogen-bond scheme is similar to those found in several salts of nucleosides and deoxynucleosides.
Quenching of Excited Mercury Atoms(63P1 and 63P0) in Molecular Collisions
Authors: Horiguchi Hiroyuki , Tsuchiya Soji
Published: July 2006

The lifetime of Hg(63P0) in a gaseous mixture of Ar and N2 with quenching molecules (Q) was measured by monitoring the decay of the Hg(63P0) concentration following the excitation of Hg by pulsed 253.7 nm radiation. The lifetime in the absence of Q was reduced with the increase in the N2 pressure, being inversely proportional to the total pressure. This can be attributed to the deactivation by impurities involved in the gas and that by collision on the wall of the reaction cell. Deactivation due to impurities is dominant at a total pressure higher than 50 Torr. With quenchers in the mixture, the lifetime measurement gave the quenching cross-section of Hg(63P0). In addition, the measurement of the stationary concentration of Hg(63P0) made it possible to determine the rate for each of the processes 63P1→63P0 and 63P1→61S0. Based on the observed ratio, α=σ2(63P1→61S0)/σ2(63P1→61S0), quenching molecules are classified into three groups. The first group consists of N2O, O2, C2H4, C3H6, and C2H2 with α1.2 These molecules deactivate Hg(63P) to form their triplet states. The second group (CO, NO, H2, C3H8, i-,n-C4H10, and C(CH3)4) in which α≈4 makes the quenching via a short-lived complex (Hg–Q)*. The last group (CH4 and C2H6) has a value of α larger than 100. This is caused by a weak interaction between potential surfaces of Hg(63P)+Q and Hg(61S)+Q.
Metal Complexes of Amino Acids. V. μ-Aminocarboxylato Bi- and Tri-nuclear Complexes of Cobalt(III)
Authors: Yasui Takaji , Ama Tomoharu , Morio Hideki , Okabayashi Minahiro , Shimura Yoichi
Published: July 2006

Some new binuclear and trinuclear complexes containing μ-aminocarboxylato ligands, [(NH3)5Co(OCORNH2)Co NO2(acac)2](ClO4)2 (R=CH2, (CH2)2, and CH(CH3) for glycinato, β- and Dl-alaninato ligands) and [en2Co{(OCORNH2)Co NO2(acac)2}2]ClO4 (R=CH2 and (CH2)2), have been prepared and characterized on the basis of their elemental analyses, visible and ultraviolet absorption, infrared, and PMR spectra. It was concluded that the NH2 end of the μ-aminocarboxylato bridge occupies a coordination position trans to the NO2ligand, and the COO ends of two μ-aminocarboxylato bridges in the trinuclear complex occupy positions trans to each other.
Synthesis of Chelating Agents. XI. Synthesis and Chelating Behavior of Diaxial trans-Decahydronaphthylene-trans-2,3-dinitrilotetraacetic Acid
Authors: Yano Tairoku , Kobayashi Hiroshi , Ueno Keihei
Published: July 2006

Diaxial trans-decahydronaphthylene-trans-2,3-dinitrilotetraacetic acid (D[A.A]TA) was synthesized by carboxymethylation of diaxial trans-decalin-trans-2,3-diamine. The acid dissociation constants as well as chelate stability constants for alkaline earth metal ions were determined by potentiometric titration. The probable structure and chelating behavior of D[A.A]TA in aqueous solutions were discussed in reference to some related complexane ligands.
Heat of Evaporation of Polyoxyethylene Dodecyl Ethers
Authors: Nakamura Masao , Eda Kazuo , Kosiyama Kiiti
Published: July 2006

The heat of evaporation has been measured by the vapor pressure method for polyoxyethylene dodecyl ethers, C12H25(OC2H4)nOH (n=0, 1, 2, 3, and 4). It has been deduced that the polyoxyethylene chain is in a cyclic state in the vapor phase due to the intramolecular hydrogen bonding of the terminal OH group with an oxygen atom in the chain.
Field Ionization of Highly-excited Helium and Hydrogen Atoms Produced by Electron Impact
Authors: Shibata Takemasa , Fukuyama Tsutomu , Kuchitsu Kozo
Published: July 2006

The ionization of long-lived highly-excited helium atoms produced by electron impact was observed using an electrostatic field up to 8.3 kV/cm; the decrease of the He+ intensity produced by collisions of He** with H2O was measured as a function of the field strength using a mass filter. By use of the theory of Bailey et al., the principal quantum numbers of the highly excited He were estimated to range from 16 to 40. A similar but slower decrease of H+ due to H** atoms produced by electron impact on H2O was also observed.
The Properties of the Liquid Nitron Nitrate Membrane Electrode
Authors: Tateda Akira , Murakami Hiroko
Published: July 2006

The preparation and properties of the nitron nitrate nitrobenzene liquid membrane electrode, which is responsive to nitrate ions, are described. Special attention is given to the selectivity characteristics. High selectivities for NO3− over NO2−, C2H3O2−, Cl−, CrO42−, and SO42− were observed.
The Solid-State Spectra of Several Rhodizonates
Authors: Aihara Jun-ichi
Published: July 2006

The charge-transfer transitions between the anions were observed in the absorption spectra of alkalimetal rhodizonates in the solid state. Ammonium ions enhanced the electronic transition of this kind, whereas the solid-state spectrum of the barium salt was similar to the solution spectrum of the rhodizonate ion.
The Tautomerism of 2-Amino-5-nitrosotropone
Authors: Imafuku Kimiaki , Takata Yasuyoshi , Matsumura Hisashi
Published: July 2006

It was confirmed that 2-amino-5-nitrosotropone (II) exists in its tautomeric form (lIb) by the measurement of its dissociation constant and UV spectra.
Kinetic Studies on Olefin Epoxidation by Peroxo Molybdenum Complex (MoO(O2)2HMPT)
Authors: Arakawa Hironori , Morooka Yoshihiko , Ozaki Atsumu
Published: July 2006

Oxidation of olefin by peroxo molybdenum complex selectively yields epoxide at room temperature. The nature of the interaction of olefin with molybdenum and that of the peroxo molybdenum complex has been investigated in terms of coordination constant K of olefin and rate constant k2 of decomposition of the peroxo molybdenum-olefin complex, attention being paid to the substituent effect of olefin. The coordination constant increases with the extent of alkyl substitution on double bonded carbon, a tendency opposite to that on Pd(II), or Rh(I). The coordination state of olefin on molybdenum seems to differ from that on Pd(II) or Rh(I), for which π-back donation of metal d-electron is accepted to play an important role. The coordination complex on molybdenum is accordingly assigned to a π-complex with some electron donated to molybdenum. A remarkable steric effect of alkyl substituent is observed, disclosing a difference from the oxidation of uncoordinated olefin. Since k2 increases with K, revealing a similar substituent effect of olefin, the peroxo oxygen seems to be electrophilic, and the peroxo oxygen-molybdenum bond seems to be rather covalent than ionic, thus giving rise to epoxidation.
A Study of the Inosine–Hydrochloric Acid–Water and Inosine–Sulfuric Acid–Water Systems
Authors: Suzuki Yoshihisa , Toki Tadao
Published: July 2006

Solubility data have been obtained for the inosine–HCl–H2O and inosine–H2SO4–H2O systems at 5°C. The acid hydrolysis of inosine was satisfactorily prevented under the present conditions. Three new acid salts of inosine have been obtained: (1) C10H12N4O5·HCl·(l/2)H2O in the A-form, (2) C10H12N4O5·HCl·(1/2)H2O in the B-form, and (3) C10H12N4O5·H2SO4·2H2O. Their X-ray powder diffraction data are given. All of them are incongruent and decomposed by pure water; however, they are stable in air during storage at room temperature.
The Singlet-Triplet Absorption Spectra of Heterocyclic Amine iV-Oxides. II. Pyridine N-Oxide Derivatives
Authors: Yamakawa Masumi , Ezumi Kiyoshi , Mizuno Yoshiko , Kubota Tanekazu
Published: July 2006

The singlet-triplet absorption spectra of various pyridine N-oxide derivatives with an electron-donating substituent have been observed by applying the oxygen-intensification technique. The nature of the lowest triplet (T1 states of these N-oxides and the substituent effect on the T1 state of pyridine N-oxide have been discussed experimentally and theoretically. The T1 states of the above substituted pyridine N-oxides were assigned to a π-π* transition of a 3La (CT) nature; 3A1 for the p-substituted pyridine N-oxides. All the singlet-triplet absorption bands as well as the singlet π-π* bands recorded here show a blue shift in polar solvents; this phenomenon is also discussed. Last, the mutual relation between the contact charge-transfer bands and the singlet-triplet absorption bands, both enhanced by compressed oxygen, has been discussed, since, for pyridine N-oxides with p-N(CH3)2, p-OCH3, and m-NH2, we could not record the singlet-triplet absorption band clearly.
Synthesis of Chelating Agents. X. Chelating Behavior of 1,2-Diamines with Specific Configurations: cis- and Diequatorial trans-Diamino-trans-decalins, cis- and trans-Diaminotetralins and 3,3-Dimethyl-1,2-diaminobutane
Authors: Yano Tairoku , Kobayashi Hiroshi , Ueno Keihei
Published: July 2006

Stability constants were determined at 25 °C for the metal chelates of racemic cis- and diequatorial trans-2,3-diamino-trans-decalins, cis- and trans-2,3-diaminotetralins and 3,3-dimethyl-1,2-diaminobutane (BEDA), where Cu(II), Ni(II) and Zn(II) are metal ions. Alicyclic trans-diamines afforded 1 :1 complexes more stable than those with cis-isomers, regardless of the metal ions. Stability of the metal chelates with BEDA is comparable to that of the trans-diamines. The difference in stability of the trans- and cis-diamine complexes increased in the order Cu-, Zn- and Ni ions. Upon formation of 1 : 2 complexes, it became greater with Ni ion, but practically no difference was observed with the others. An explanation was given on the basis of stereochemistry of the diamines and coordination structures of the divalent metal ions.
Binuclear Metal Complexes. XIII. Syntheses and Magnetic Properties of Thiocyanato-Bridged Binuclear Copper(II) Complexes
Authors: Ichinose Tomoko , Nishida Yuzo , Okawa Hisashi , Kida Sigeo
Published: July 2006

Three binuclear copper(II) complexes, Cu2(fsal-NMe2)(NCS)3, Cu2(fsal-NEt2)(NCS)3 and Cu2(fsal-pa)(NCS)3, have been synthesized and characterized, where Hfsal-NMe2, Hfsal-ENt2 and Hfsal-pa denote the Schiff bases prepared by the condensation reaction of 2,6-diformyl-4-methylphenol with N,N-dimethylethylenediamine, N,N-diethylethylenediamine and 2-pyridylmethylamine, respectively. It was demonstrated that the complexes essentially consist of a binuclear unit of the thiocyanato-bridged skeleton, (Remark: Graphics omitted.). The cryomagnetic properties could be explained on the basis of the equation for the tetranuclear cluster formed with two binuclear units linked by the out-of-plane bonding. The magnetisms and structures of the complexes were discussed in comparison with those of the Cu2(fsal–NR2)X3 (X=Cl, Br).
Six-coordinate Copper(II) Complexes Derived from the Reactions of Bis(acetylacetonato)- and Bis(ethyl acetoacetato)-copper(II) with Some Bidentate Nitrogen Bases
Authors: Kurauchi Takeo , Matsui Masanori , Nakamura Yukio , Ooi Shun’ichiro , Kawaguchi Shinichi , Kuroya Hisao
Published: July 2006

Green-to-blue six-coordinate mixed complexes, Cu(acac)2(en) and Cu(etac)2(diamine)(acac=acetylacetonate anion; etac=ethyl acetoacetate anion; diamine=ethylenediamine, trimethylenediamine, 2,2′-bipyridine or 1,10-phenanthroline) have been isolated by the reactions of the respective parent β-diketonate with the corresponding diamine in dry dichloromethane. On the other hand, the reaction of Cu(acac)2 with en in the mole ratio of one-to-two in dichloromethane saturated with water has resulted in purple crystals of Cu(acac)2(en)2·2H2O. This compound has been shown by X-ray analysis to consist of a square-planar copper(II) cation, coordinated by two ethylenediamine molecules, and two planar acetylacetonate anions, the plane of which is not perpendicular to, but slanted against, the CuN4 plane. One oxygen atom of the anion participates in the N–H···O hydrogen bonding with an NH2 group of the ethylenediamine molecule, while the other occupies the axial position of Cu(en)22+ (Cu···O: 2.79(1) Å). Therefore, the compound can be designated by the formula [Cu(en)2]·(acac)2·2H2O. The water hydrogen atoms seem to take part in the hydrogen bonding with the anion oxygen atoms.
Circular Dichroism Spectra of Cobalt(III) Complexes Containing Amino-Alcohols
Authors: Nishide Toshikazu , Ogino Kazuko , Fujita Junnosuke , Saito Kazuo
Published: July 2006

Several cobalt(III) complexes containing amino-alcohol (amOH) chelate rings, [Co(amOH)(NH3)4]X3, [Co(amOH)(en)2]X3 and [Co(amOH)(R-chxn)2]X3 (en=ethylenediamine, chxn=trans-1,2-diaminocyclohexane, X−=Cl−, Br− or ClO4−, amOH=2-aminoethanol, 2-amino-1-propanol, 1-amino-2-propanol, etc.) were synthesized and separated into optical isomers. Their circular dichroism (CD) spectra change remarkably by the change in pH of the solution. The changes were ascribed to the dissociation of the alcoholic proton of coordinated amOH. The complexes containing a deprotonated chiral amO− chelate ring exhibit strong vicinal CD bands in the first and second absorption band region. The signs and the magnitudes of these CD bands seem to depend mainly on the conformation of the amO− chelate ring.
Abnormal Benzo Substituent Effect on Free Radical Formation Process. A Local Symmetry Effect
Authors: Tabushi Iwao , Yoshida Zen-ichi , Aoyama Yasuhiro
Published: July 2006

Relative stabilities of 1-bicyclo[2.2.2]octyl (9), 1-benzobicyclo[2.2.2]-octenyl (10), 1-dibenzobicyclo[2.2.2]octadienyl (11), and 1-tribenzobicyclo[2.2.2]octatrienyl(12) radicals were obtained by means of the relative rates of the free radical bromine abstraction from the corresponding bridgehead bromides by a silyl radical. It was found that 9 and 12 were more stable than expected. The observed order of stability 9>10>12>11 can not be explained by the usual concepts alone. The extra stabilization of 9 or 12 (or destabilization of 10 or 11) was interpreted in terms of the local symmetry (or local asymmetry) of these radicals.
The Photochemical Raction of 2-Alkoxy-1,4-naphthoquinones with Olefins. II. The Formation of Tetrahydropyran-ring Compounds
Authors: Otsuki Tetsuo
Published: July 2006

The photochemical reaction of 2-alkoxy-1,4-naphthoquinones with numerous types of olefins was investigated. The reaction was found to proceed smoothly in possible combinations of quinones and olefins to give photo-addition compounds in good yields. The structure of the addition compounds was determined to be 10 by their elemental analyses, mass, IR, PMR, and chemical reactions. The photo-addition reaction is characterized by the formation of a tetrahydropyran ring. This type of photo-addition reaction has not been previously known. The scope and limitations of the new photochemical reaction were described.
Spectrophotometric Studies of the Acidities of Dichlorophene and Hexachlorophene
Authors: Inoue Hiroyasu , Asaoku Naomi
Published: July 2006

It has been found that dichlorophene (bis-(2-hydroxy-5-chlorophenyl)methane) and hexachlorophene (bis-(2-hydroxy-3,5,6-trichlorophenyl)methane) have abnormally high acidities as compared with the corresponding reference compounds, i.e., 2-methyl-4-chlorophenol and 2,4,5-trichlorophenol respectively. The values of pKa for the first and second ionizations of dichlorophene in a mixed solvent of ethanol and water (1 : 1) were determined to be 9.10 and 13.1, and those of hexachlorophene, to be 5.87 and 11.9, at 18 °C. On the basis of the infrared spectra, these observations could be interpreted in terms of the additional stabilization of the resulting monoanions of these bis-phenolmethanes by means of the intramolecular hydrogen bondings between the OH and O− groups.
α,β-Unsaturated Carboxylic Acid Derivatives. VI. New Synthesis of N-Acyl-α-dehydroamino Acid Esters
Authors: Shin Chung-gi , Nanjo Katsumi , Ando Eiichi , Yoshimura Juji
Published: July 2006

A new synthetic route to α,β-unsaturated N-acyl-α-amino acid esters (N-acyl-α-dehydroamino acid esters) is described. The dehydroamino acid esters were prepared by the dehydration of α-(N-acylhydroxyamino) acid esters (10), derived from the acylation of α-hydroxyamino acid esters (2 and 6), and by the elimination of carboxylic acid from α-(N-acyl-O-acetyl), α-(N,O-diacetyl, dipropionyl and diethoxycarbonyl-hydroxyamino) acid esters, obtained by the acylation of 2, 6 and 10, in the presence of triethylamine.
Factors Affecting: the Line-width of Nitrogen Superhyperfine Structure in the ESR Spectra of Copper(II) Complexes
Authors: Nonaka Yasuomi , Tokii Tadashi , Kida Sigeo
Published: July 2006

ESR spectra were measured for several series of copper(II) complexes in an attempt to find the best-observable condition for 14N-superhyperfine structure. It was demonstrated that in addition to the temperature and the dilution factors the line-width of 14N-superhyperfine structure is broadened out by the following factors; 1) deviation from square planar configuration around a copper ion, i. e., deformation to elongated octahedron or square pyramid due to weak bonding along the tetragonal axis and/or distortion of coplanality of the coordination bond effected by some steric condition, and 2) the presence of protons that can couple with an unpaired electron and 14N-nuclei.
The Thermal Polycondensation of Glycine in the Presence of Urea
Authors: K\={o}zai Yasuaki , Ikeda Yoshiyuki , Yoshida Masakazu
Published: July 2006

After the discovery of the polycondensation of glycine to form the glycine oligomer by heating in the presence of urea in a sealed tube, we investigated in order to establish the optimum reaction conditions as well as to study the reaction mechanism. The optimum conditions are attained when a mixture of 0.0133 mol (1 g) of glycine and 0.0016 mol (0.1 g) of urea is heated at about 160 °C for 20–30 hr. Under these conditions, an oligomer, composed of glycine units, with a polymerization degree of 17–18 is obtained with a 50–52% yield. The mechanism of oligomer formation is considered to be as follows: first, the urea is melted and part of it is used for converting the glycine to the corresponding amide. The glycinamide thus formed and the glycine dissolve locally in the molten urea, resulting in condensation between them. A repetition of the condensation leads to longer peptide chains.
Methylene Analogs of Cyclobutenedione. VIII. The Oxidation of 1-Halo-and 1,2-Dihalo-3,4-bis(diphenylmethylene)cyclobut-1-enes
Authors: Toda Fumio , Monden Fumio , Ohi Mitsuru
Published: July 2006

The ether peroxide-catalyzed oxidation of 1-chloro- (X) and 1,2-dichloro-3,4-bis(diphenylmethylene)cyclobut-1-enes (V) afforded two ring-opened products, XI and VI respectively. However, neither X nor V was oxidized by photooxidation. By the photooxidation, 1-bromo- (XVI) and 1,2-dibromo-3,4-bis(diphenylmethylene)cyclobut-1-enes (II) were converted to cyclobutanones, XIII and I respectively. Although II was inert to the peroxide-catalyzed oxidation, XVI was oxidized by this procedure. Nevertheless, the main product of the latter reaction was the cyclobutanone (XIII). The mechanisms of these reactions were described.
Dye-sensitized Photolysis of Diazonium Compounds in the Presence of Thioacetamide
Authors: Inoue Eiichi , Kokado Hiroshi , Ikawa Tsuneo , Yamase Toshihiro , Inoue Yasuo
Published: July 2006

Effects of solution pH and molecular oxygen on the quantum yields of methylene blue-sensitized photolysis of diazonium salt have been studied in aqueous solutions, using thioacetamide as an activator. The quantum yield increased with an increase in pH when other parameters were kept constant. The presence of oxygen at pH (<7) promoted dye sensitization, but at pH (>7) dominance of the pathway of oxygen quenching of the excited dye triplet caused its suppression. The polymerization of acrylamide in the deaerated solution was readily initiated by dye-sensitized photolysis. A mechanism involving an electron transfer to diazonium cation from unprotonated semimethylene blue formed by a photoredox reaction between excited triplet dye and thioacetamide was in line with these observation.
Magnetic Susceptibilities of Octacoordinated Uranium (IV) Complexes
Authors: Yoshimura Tetsuhiko , Miyake Chie , Imoto Shosuke
Published: July 2006

Magnetic susceptibility measurements were carried out on octacoordinated uranium(IV) complexes, such as tetrakis(acetylacetonato)uranium (IV), tetrakis(trifluoroacetylacetonato)uranium (IV), tetrakis(benzoylacetonato)uranium(IV), tetrakis(dibenzoylmethanato)uranium(IV), tetrakis(thenoyltrifluoroacetonato)uranium(IV), tetrakis(cupferronato)uranium(IV), and uranium(IV)tetrachloride, in the temperature range from room temperature to the temperature of liquid nitrogen or liquid helium. The Curie-Weiss law holds above the temperature of liquid nitrogen, with a magnetic moment of 3.5–2.92 BM. For the latter two complexes, a temperature-independent paramagnetism was observed in the low temperature range; the other complexes also seemed to show the same trend. We tried to interpret the magnetic behavior on the basis of the crystal-field model of the square antiprism structure or the dodecahedron structure of the complexes.