bluuebunny/crossref_metadata_2025 huggingface dataset:
The Derivation of the rs Structure by the Use of a Nondiagonal Weight Matrix for Rotational Constants
Authors: Hirose Chiaki
Published: July 2006

The use of a nondiagonal weight matrix in a least-squares analysis of the quantities which themselves are derived from another least-squares analysis is discussed in relation to the analysis of rotational constants in determining molecular geometry. The method is applied to the calculation of the rs structure of ethylene oxide, and the result is compared with those obtained by Kraitchman’s formula and by a least-squares fit by the use of a diagonal weight matrix.
Solution Properties of Phycocyanin. II. Studies of the Molecular Shape and Size by Using the Shell Model
Authors: Kotera Akira , Saito Takahide , Iso Naomichi , Mizuno Haruo , Taki Nobuo
Published: July 2006

The number-average molecular weight and intrinsic viscosity of phycocyanin, isolated from Porphyra tenera, have been determined by osmotic pressure and viscosity measurements at various values of pH and ionic strength. The molecular shape and size for phycocyanin aggregates were also discussed by comparing the experimental values of sedimentation coefficient and intrinsic viscosity with the calculated results obtained by using the shell model theory. It is shown that the aggregate of phycocyanin at pH 5.4 is a hexamer of molecular weight 256000 and the structure consists of six juxtaposed monomers. The monomer is a prolate ellipsoid of 35 Å in diameter and 105 Å length. This structure for the hexamer is consistent with the model proposed by Jennings. At pH 6.8, it is shown that the number-average molecular weight of phycocyanin depends on the ionic strength in solution.
A Semi-empirical Calculation of the Substituent Effects on 1H Chemical Shifts in Aromatic Side-chains
Authors: Niwa Jun
Published: July 2006

The diamagnetic contribution of the hydrogen atom, in the C–H bond and that from its bonded carbon have been semi-empirically expressed. By considering the “ring-current” effect in addition to such contributions, a semi-empirical expression has been obtained for 1H chemical shifts relative to the unsubstituted compound in substituted aromatic side-chains. The applicability of the expression has been examined for m- and p-substituted phenylacetylenes, styrenes, toluenes, and benzaldehydes.
Substitution and Hydrogen Bonding Effects on Fluorescence and Intersystem Crossing in Naphthaldehydes and Their Derivatives
Authors: Kitamura Michio , Baba Hiroaki
Published: July 2006

Absorption and fluorescence spectra, fluorescence and phosphorescence quantum yields and lifetimes of 1-and 2-naphthaldehyde and their derivatives have been measured in rigid glass solution at 77 K. Naphthaldehydes and acetonaphthones are non-fluorescent, whereas naphthoyl chlorides and methyl naphthoates are fluorescent. Upon formation of a hydrogen bond with ethyl alcohol, 2-naphthaldehyde and 2-acetonaphthone become fluorescent, and 1-naphthoyl chloride increases in fluorescence quantum yield by a factor of about 65. The rate constants for intersystem crossing in these three molecules decrease by about two orders of magnitudes as a result of hydrogen bonding. The decrease of the rate constants is attributed to elevation of the (n, π*) level and the resulting change in its position relative to the (n, π*) level. The experimental results are discussed in relation to the current theories of radiationless transition, and are found to conform to the theory in which both spin-orbit coupling and nuclear kinetic-energy operators are treated as the perturbation causing intersystem crossing.
Normal and Reverse Photochromism of 1-(β-carboxyethyl)-3,3-dimethyl-6′-nitrospiro[indoline-2,2′-2H-benzopyran] in Water–Dioxane
Authors: Namba Kenryo , Suzuki Shuichi
Published: July 2006

The photochromism of 1-(β-carboxyethyl)-3,3-dimethyl-6′-nitrospiro[indoline-2,2′-2H-benzopyran] (I) was studied in water-dioxane. It was found that (I) exhibits normal photochromism in dioxane and reverse photochromism on addition of water to the solution.
Synthesis of Arylethylenesulfonamides and Intramolecular Rearrangement of N-(Arylethylenesulfonyl)thioureas
Authors: Hasegawa Kiyoshi , Hirooka Syuzi , Sasaki Tadashi
Published: July 2006

The reactions of p- and p′- substituted N-(2,2-diarylethylenesulfonyl)- (8), N-[2-phenyl-2-(α-naphthyl)ethylenesulfonyl]- (9), and N-(p-nitrostyrene-1-sulfonyty)-N′-alkylthioureas (12) with bases afforded new intramolecularly rearranged N-alkyl-S-(2,2-diarylvinyl)- (13), N-alkyl-S-[2-phenyl-2-(α-naphthyl)vinyl]- (14), and N-alkyl-S-(p-nitrostyryl)isothioureas (15), respectively, p- and p′-Substituted 2,2-diarylethylene-N-methylsulfonamides (6) were treated with carbon disulfide and alkyl halides in the presence of a base to give alkyl 2,2-diarylvinyl trithiocarbonates (17). The order of reactivity of the sulfonylthioureas and -amides indicates that the rearrangement is retarded by electron-releasing p-substituents on benzene rings (Cl>H>CH3>OCH3).
Electron-transfer Kinetics of Transition-metal Complexes in Lower Oxidation States. Part III. Electrochemical Rate Constants for the Fe(II)/Fe(I) Redox Systems
Authors: Saji Tetsuo , Yamada Tamaki , Aoyagui Shigeru
Published: July 2006

The standard rate constants for the redox systems Fe(II)/Fe(I) are measured. They are about one tenth of those for the systems Fe(III)/Fe(II) and Cr(I)/Cr(0). The difference in the kind of molecular orbital occupied by the excess electron of the reductant species can account for the difference in the rate constant.
The Cycloaddition Reaction of Isobenzofuran with Fulvenes: The Formation of an endo-(6+4)π Adduct
Authors: Takeshita Hitoshi , Mori Akira , Sano Sansei , Fujise Yutaka
Published: July 2006

Isobenzofuran (I) was shown to react at 160 °C with 6,6-diphenylfulvene to give two endo-(2+4)π cycloadducts, an endo-1: 1-adduct and an endo-anti-endo-1: 2-adduct. On the other hand, I and 6,6-dimethylfulvene gave an endo-(6+4)π cycloadduct at room temperature.
The Reflection Spectra of Complex Salts of the Tetracyanoquinodimethane Anion Radical
Authors: Oohashi Yukako , Sakata Tadayoshi
Published: July 2006

Reflection measurements of the pressed pellets of two 2 : 3 complex salts and six 1 : 2 complex salts of the tetracyanoquinodimethane (TCNQ) anion radical were carried out over the 5000–43000 cm−1 range by the use of Avery’s method. The polarized normal-incidence reflection was measured for the Ph3PCH3(TCNQ)2single crystal. The observed results were examined on the basis of the composite-system method. For 2 : 3 salts, the transition energy and the oscillator strength are interpreted by the use of the N-A-A model (N: TCNQo and A-A: TCNQ anion dimer); it is concluded that the interaction between the two components, N and A-A, is weak. In the solid-state spectra of 1 : 2 salts, the assignments were made by the use of the polarization results of the normal-incidence reflection of the Ph3PCH3(TCNQ)2 crystal. Besides the four transitions corresponding to those of 2 : 3 salts, two new CT bands with weak intensities were observed and assigned. Except for quinolinium(TCNQ)2, a spectral change correlative to the electrical conductivity was found in the 1 : 2 salts and discussed in relation to the extent of the delocalization of the negative charge of (TCNQ)2−. The spectrum of quinolinium(TCNQ)2 exhibits a remarkable intensity decrease compared with those of the other 1 : 2 salts.
Effects of Electrolytes on Properties on Black Films and Foam Stability of Aqueous Nonionic Surfactant Solutions
Authors: Yamanaka Teruko
Published: July 2006

The properties of black film, the surface tension of solution and the foam stability in the aqueous solutions of polyoxyethylene-type nonionic surfactants containing various electrolytes were studied. The additional tension \barΔ of black films showed a maximum and a minimum in the concentration range of electrolytes of 1×10−5–1 N. The concentration at this minimum shifted in accordance with the lyotropic series of anions. The surface tension was unaffected by the electrolyte of the concentration less than about 1×10−2 N, whereas \barΔ exhibited a maximum in this range. The overall rate of growth of the black film was found to be proportional to \barΔ over a wide range of electrolyte concentration. The effects of electrolytes on the foam stability were discussed being based upon the properties of the black films.
The Fluorometric Determination of Gallium in Aluminum Metal with 8-Quinolinethiol
Authors: Watanabe Kunihiro , Kawagaki Ky\={o}z\={o}
Published: July 2006

A method for the fluorometric determination of gallium in aluminum metal is presented which involves extraction with the methyl isobutyl ketone (MIBK) of the gallium 8-quinolinethiolate complex. The extracted complex has a greenish-yellow fluorescence, with an emission maximum at 505 nm. The maximum fluorescence intensity is obtained at a pH of the initial aqueous phase of around 3.3; the fluorescence remains stable for at least 2 hr. When 50 ml of a sample aqueous solution containing gallium and 0.2 ml of a 0.2% 8-quinolinethiol solution is subjected to extraction with 10 ml of MIBK, the quantity of gallium which can be present for determination in the sample solution amounts to 1 to 30 μg. For the removal of the interfering effects of zinc, cadmium, copper, and nickel on the fluorometric determination, gallium was extracted with isopropyl ether from a 7 M HCl solution. The relative error of this method was 5% for 0.019% gallium in aluminum metal.
Studies on the Hexagonal Hydrate of Molybdenum Trioxide. The Physical Properties of the Hydrate and Its Changes on Heat Treatments in Air, in Hydrogen, and in a Hydrogen–thiophene Mixture
Authors: Sotani Noriyuki
Published: July 2006

The hexagonal hydrate (I) of molybdenum trioxide, which has been newly found and reported, was studied by X-ray diffraction analysis, IR and NMR spectroscopies, and by other methods. Also studied was the change in (I) on heat treatments in air, in hydrogen, and in a hydrogen–thiophene mixture. The crystal was found to belong to a hexagonal system. The air-dried sample has about 0.46 mol of water. This water is included as a water molecule, not as hydroxyl. By the dehydration of (I), anhydrous molybdenum trioxide (I′), which has the same crystal structure as (I), is obtained. Another new form of (I′) is the hexagonal trioxide, which is hygroscopic and which easily absorbs water when standing in air. This (I′) is metastable and is irreversibly transformed to rhombic molybdenum trioxide(II) at 420–430 °C. In hydrogen and in a hydrogen-thiophene mixture, reduction and sulfurization occur in addition to transformation, which can be shown schematically as: (Remark: Graphics omitted.). Transformation in hydrogen and in the hydrogen–thiophene mixture proceeds faster than in air. Reduction occurs more quickly in the hydrogen–thiophene mixture than in hydrogen.
Studies of the Preparation and Physical Properties of Multivalent Metal Condensed Phosphates. Part XI. The Preparation of Various Aluminum Phosphates and Their Thermal Transformation
Authors: Tsuhako Mitsutomo , Hasegawa Kazuko , Matsuo Tsuneo , Motooka Itaru , Kobayashi Masamitsu
Published: July 2006

In the reaction of Al2O3 or Al(OH)3 with phosphoric acid, the conditions of the formation of the I and II types of aluminum dihydrogen tripolyphosphate, AlH2P3O10, and the A and B types of aluminum tetrametaphosphate, Al4(P4O12)3, were established. The I and II types of AlH2P3O10 were chiefly obtained at 300 °C; the formation of the I type predominated when the water content of the primary product was 15–30%, while the II type was more readily formed at a water content of 10–15%. Also, the I and II types were easily formed at vapor pressures of 1–5 atm. Al4(P4O12)3 was produced when the water content was less than 10% or more than 30%. On the other hand, the A and B types of Al4(P4O12)3 were easily formed at 500 °C; the A type was chiefly formed when the water content was below 10% or above 25%, while the B type was produced at the water content of 10–25%. The water content of the primary product is presumably due to the dehydration caused by the condensation of the P–OH. Thus water, effective for the formation of aluminum phosphates, is the structural water (P–OH). Further, the B type was liable to be formed on rapid dehydration, while the A type was more readily produced on slow dehydration. Accordingly, the formation of aluminum phosphate has been confirmed to be greatly dependent on the water content of the primary product and on the vapor pressure in the secondary heat treatment.
The Reaction of Aroyl Alkyl Carbonates with Isocyanates
Authors: Uchida Yuzuru , Kozuka Seizi
Published: July 2006

Aroyl alkyl carbonates were treated with isocyanates with or without addition of sodium methoxide and alkyl N-aroylcarbanilates were obtained as the major products. Based on 18O tracer study and catalytic effect of alkoxide ion, a base catalyzed ionic reaction process was confirmed for the mechanism of the carbanilate formation.
The Mannich Reaction of Alicyclic α-Diketones. A Novel Synthesis of 2-Hydroxy-3-methyl-2-cyclohexen-1-one
Authors: Ohashi Masao , Takahashi Tadashi , Inoue Seiichi , Sato Kikumasa
Published: July 2006

A new synthesis of 2-hydroxy-3-methyl-2-cyclohexen-1-one (1) is described. The Mannich reaction of cyclohexane-1,2-dione (2) or 2-morpholino-2-cyclohexen-1-one (3) with morpholine and formalin gave a Mannich base (4), which was then hydrogenolized to afford 1. However, the Mannich reaction of 1 merely gave a bis-Mannich base (22), which was then similarly hydrogenolized to afford 3,6-dimethyl-2-hydroxy-2-cyclohexen-1-one (7) along with 3,6-dimethyl-2-hydroxy-6-morpholinomethyl-2-cyclohexen-1-one (26); 2-hydroxy-3,6,6-trimethyl-2-cyclohexen-1-one could not be obtained under these conditions. The Mannich reaction of other alicyclic α-diketones and the hydrogenolysis of their Mannich bases are also described.
Coenzyme Models. II. Effect of Micellar Environments on the Acid-Catalyzed Hydration of 1,4-Dihydropyridine Derivatives
Authors: Shinkai Seiji , Ando Reiko , Kunitake Toyoki
Published: July 2006

An effect of micelles on the acid-catalyzed modification reaction of two dihydropyridines is reported in connection with the NADH function bound to alcohol dehydrogenase, and the hydration equilibrium of dihydronicotinamides was found to be quite susceptible to the ionic environment. The absorption maximum at 357 nm of 1-benzyl-1,4-dihydronicotinamide(NBzNH) was not affected by the presence of cationic micelles, while that of 1-lauryl-1,4-dihydronicotinamide(NLaNH) shifted by 5–6 nm to shorter wavelengths, probably due to the neighboring cationic charge. The hydration rates for dihydronicotinamides were prompted by NaLS micelle and retarded by CTAB micelle. The rate augmentation in the NaLS micelle, compared with the non-micellar system, was 1.7-fold for NBzNH and 33-fold for NLaNH. On the other hand, CTAB micelle pronouncedly depressed the hydration rate of NLaNH, which is 414-fold slower than in NaLS. The micelle of 1-lauryl-3-carbamoylpyridinium(NLaN), which forms the charge transfer complex with NLaNH, was found to inhibit the acid-catalyzed hydration more efficiently (1400-fold slower). Thus, it is suggested that the ammonium ion adjacent to the dihydronicotinamide group in alcohol dehydrogenase–NADH complex performs some biological functions.
Reaction of Group IV Organometallic Compounds. XXXII Modified Synthesis of Imidazolidines with N,N′-Bis(trimethylsilyl)-1,2-diamines
Authors: Suzuki Hiroharu , Ohashi Masayasu , Itoh Kenji , Matsuda Isamu , Ishii Yoshio
Published: July 2006

N,N′-Bis(trimethylsilyl)-1,2-diamines gave imidazolidine derivatives accompanied with the elimination of hexamethyldisiloxane in excellent yields by condensation reactions with carbonyl compounds under mild conditions. These reactions are regarded as the typical addition-elimination reaction of group IV organometallics.
The Photovoltaic Effect in Naphthacene–Gold Layers
Authors: Matsumura Michio , Uohashi Hiromichi , Furusawa Masaki , Yamamoto Naoto , Tsubomura Hiroshi
Published: July 2006

The photovoltaic effect in gold–naphthacene thin layers has been studied. By excitation in the region of the visible absorption band of naphthacene (2.4–3.0 eV), it was found that the photovoltage consists of two components; one with a short response time, caused by the electron transfer across the boundary between gold and naphthacene, and the other with a long response time, attributable to a diffusion process in the naphthacene film. The lifetime of carriers produced by the former process was estimated to be 0.08 s at least, decaying by the recombination of trapped holes in naphthacene with electrons in gold. Photovoltage was also observed in a region of wavelengths greater than the visible absorption band of naphthacene.
ESR Studies of the Structures and Spin-exchange Interactions of the Dimers of Nitro-substituted Salicylaldehyde Schiff-base Complexes of Copper(II) in Frozen Solutions
Authors: Chikira Makoto , Isobe Taro
Published: July 2006

The computer simulations of the ESR spectra for the triplet-state dimers of the title complexes in frozen solutions revealed that the dimeric structures change markedly upon nitro-substitutions at the positions of 3 or 5 in the phenyl-rings of the Schiff bases. It was also found that some of these nitro-substituted copper(II) complexes form 1: 1 molecular complexes with bis(N-salicylideneisopropylaminato)copper(II) in toluene. The dependence of the ESR spectral intensities for the ΔM=2 transitions upon the temperature in the range of 1.57–4.2 K indicated that the intra-dimer spin-exchange interactions are weakly anti-ferromagnetic (0.7–2.2 cm−1).
Photochemistry of peri-Substituted Naphthalenes. I. Photochemistry of Dimethyl 1,8-Naphthalenediacrylate
Authors: Honda Koichi , Yabe Akira , Tanaka Hideaki
Published: July 2006

The photochemical reactions of dimethyl 1,8-naphthalene diacrylate (I) in solution are found to be cis,trans isomerization and concomitant intramolecular cycloaddition through a triplet state (ET is ca. 40 kcal/mol). Cyclization reaction gives naphtho[1′,8′]bicyclo[3.1.1]hept-2-ene-6-exo,7-endo-dimethyl dicarboxylate (VI), its 6-endo, 7-endo substituted isomer (VII) and cis-anti-naphtho[1′,8′]bicyclo[3.2.0]hept-2-ene-6,7-dimethyl carboxylate (II) in a ratio of ca. 85: 10: 5. Predominant formation of crossed adducts is discussed, taking into consideration the ground-state conformations of (I). Biradical mechanism is proposed for the cyclization to explain the stereochemistry of the crossed products.
The Formation and Structure of Copper(II) Complexes with Cyclodextrins in an Alkaline Solution
Authors: Matsui Yoshihisa , Kurita Toyoaki , Yagi Masao , Okayama Tetsuo , Mochida Kazuo , Date Yoshio
Published: July 2006

Copper(II) forms a 2: 1 complex with cyclodextrin in an alkaline solution. The complexes with α- and β-cyclodextrins were isolated from solutions by the addition of ethanol. They are labile, and, upon heating, the Cu(II) is reduced to Cu(0). The role of the hydroxide ion was examined by means of potentiometrie and conductometric titrations; it was found that the reaction of 1 mol of α-cyclodextrin with 2 mol of Cu(OH)2consumes 2 mol of the hydroxide ion, whereas 3 mol of the hydroxide ion are consumed for the reaction of β-cyclodextrin. Polarimetric measurements showed that the optical rotation of cyclodextrin changes from dextrorotatory to levorotatory upon the formation of the Cu(II)-cyclodextrin complex. It was suggested, with a molecular model, that the two pairs of C2 and C3′ secondary hydroxyl groups of contiguous glucose units are cross-linked by the Cu(OH−)2Cu ion bridge in the α-cyclodextrin complex and by Cu(OH−)(O2−)Cu ion bridge in the β-cyclodextrin complex. Furthermore, the circular ring of cyclodextrin may be distorted to the ellipsoidal form by the complex formation, causing a pronounced change in the optical rotation.
Normal Vibrations of Benzenesulfonate and Benzene-d5-sulfonate Ions
Authors: Uno Toyozo , Kuwae Akio , Saito Yutaka , Machida Katsunosuke
Published: July 2006

Infrared and Raman spectra of sodium benzenesulfonate and its fully C-deuterated derivative have been recorded in the solid state and in the aqueous solution. The normal coordinate analysis has been made for C6H5SO3− and C6D5SO3− ions based on the C2V symmetry. A valence force field was assumed and the force constants were refined by the least squares method. It was found that the diagonal force constants for the CH out-of-plane bending vibrations at the ortho and the para positions are greater than the corresponding constant for the meta position. This result reflects well the effect of the electron attractive substituent in monosubstituted benzene derivatives. The force constants obtained were transferred to p-toluenesulfonate ion successfully.
The Proof of a Triplet Ground State in the N,N′-Di-t-butyl-m-phenylenebinitroxide Biradical
Authors: Mukai Kazuo , Nagai Hiroshi , Ishizu Kazuhiko
Published: July 2006

The magnetic susceptibility of the N,N′-di-t-butyl-m-phenylenebinitroxide biradical has been measured in the temperature range from 60 to 300 K. The susceptibility follows the Curie-Weiss law, with a paramagnetic Curie constant of 0.90±0.04 K·-emu/mol and a Weiss constant of −19±2 K. This susceptibility suggests that the ground state of the biradical is a triplet and that an intramolecular pure triplet approximation, 2J>>kT, is reliable in the temperature region below 300 K. The negative Weiss constant is due to the negative exchange interaction, J′<0, between the triplets.
Studies of Bivalent Metal Chelates of 2-Aminomethylpyridine
Authors: Noji Masahide , Kidani Yoshinori , Koike Hisashi
Published: July 2006

Bivalent metal chelates of 2-aminomethylpyridine (abbreviated as 2AMP), M(2AMP)2X2 (M=Cu, Ni, Co, and Zn ion; X=Cl−, Br−, I−), were synthesized in ethanol. The magnetic moments and the diffuse reflectance spectra were measured. The Cu(2AMP)2X2 complexes (X=Cl− and Br−) were considered to have a monomeric distorted octahedral structure. The Ni(2AMP)2X2 complexes (X=Cl−, Br−, I−) were also suggested to have an octahedral structure. However, for Co(2AMP)2Br2 and Co(2AMP)2I2 a tetrahedral and a square planar structure were proposed on the basis of their magnetic moments of 4.20 and 2.78 B.M. respectively. The infrared spectra of the chelates were analysed in relation to their structures; a good relationship was found between the structures and the far-infrared spectra.
Induced Circular Dichroism of Benzyl Chromophores Bound to Helical Polypeptides
Authors: Nomori Hiroyuki , Tsuchihashi Nobuaki , Takagi Shoji , Hatano Masahiro
Published: July 2006

Extrinsic optical activity was observed for symmetric side chain chromophores in helical polypeptides. Poly-β-benzyl-l-aspartate, poly-β-p-nitrobenzyl-l-aspartate and poly-γ-p-nitrobenzyl-l-glutamate gave induced circular dichroism in the wavelength regions corresponding to the absorption bands of the benzyl and the p-nitrobenzyl chromophores of the side chains in their dilute solutions. Moreover, poly-γ-benzyl-d-glutamate gave induced circular dichroism due to the benzyl chromophore in its concentrated solutions which formed a liquid crystalline phase. The extrinsic optical activity thus observed was explained as the consequence of the loss of the rotational freedom of the chromophores relative to the α-helical structure and to the cholesteric helical structure of the polypeptides.
The Reaction of 1,2,4,5-Tetrazines with 2-Phenyl-1-azirine. The Synthesis of 2H-1,2,4-Triazepine Derivatives
Authors: Takahashi Masahiko , Suzuki Norimoto , Igari Yoshihiko
Published: July 2006

The Reaction of 3,6-disubstituted 1,2,4,5-tetrazines (1a–c) with 2-phenyl-1-azirine (2) afforded 3,7-disubstituted 6-phenyl-2H-1,2,4-triazepines (5a–c) in good yields.
ESR and ENDOR Studies of Hindered Internal Rotation of Higher Alkyl Groups in 4,4′-Dialkylbiphenyl Anion Radicals
Authors: Nemoto Fujito , Shimoda Fumio , Ishizu Kazuhiko
Published: July 2006

ESR and ENDOR spectra were obtained for the anion radicals of 4,4′-diisopropylbiphenyl, 4,4′-dicyclohexylbiphenyl and 4,4′-dicyclopentylbiphenyl. Both the β- and γ-proton coupling constants of the alkyl groups were precisely determined. The temperature dependence of the β-proton splittings of the alkyl groups were investigated. According to the Heller-McConnell relationship for hyperconjugation, a4β=(B0+B2cos2θ)ρ4π, the positive temperature dependence of the alkyl β-proton splitting was adequately interpreted utilizing a revised model with restricted rotation. The rotational potential barrier and the energy difference of the two equilibrium states obtained were 1.2 and 0.5, 1.2 and 0.6, and 1.2 and 0.6 kcal/mol for the 4,4′-diisopropyl-, 4,4′-dicyclohexyl-, and 4,4′-dicyclopentylbiphenyl anions, respectively. The energy difference of the non-bonding interatomic interaction was calculated in terms of the Lennard-Jones 6–12 potential. Excellent agreement is found between the experimentally-determined value of the potential barrier and that calculated theoretically. ENDOR observations carried out for 4,4′-dicyclohexyl- and 4,4′-dicyclopentylbiphenyl anion radicals in solution demonstrated that γ-protons revealed two different hyperfine coupling constants. These hyperfine coupling constants were assigned to the stereochemically different γ-protons. The ratio of these γ-protons splittings suggest that hyperconjugation plays an important role in producing a spin density of the γ-protons as has been proposed for explanations of the β-proton splittings.
The Photochemical Decomposition of Benzenediazonium o-Carboxylate in Several Solvents
Authors: Kato Masahiko , Tamano Taizo , Miwa Toshio
Published: July 2006

The photochemical decompositions of benzenediazonium o-carboxylate (1) in water, ethanol, acetone, and dichloromethane were studied. In every case, the initial loss of molecular nitrogen to give a zwitterion (3) and/or a diradical (4) was the primary process. In the solvents which are susceptible to hydrogen abstraction by a radical (ethanol and acetone), reduction takes place to give benzoic acid, through 4, in a good yield. In water, from which a hydrogen atom is less easily abstracted homolytically, salicylic acid was the main product (24%), while benzoic acid was the minor one (9%). In CH2Cl2, the reduction product (benzoic acid, 20%) and biphenylene (10%) were formed. The formation of the latter compound prompted us to study the photochemical decomposition of 1 in CH2Cl2 in the presence of tropone. This reaction gave cycloaddition products, (11) and (12), in 3.2 and 0.7% yields respectively.
Stereospecific [2π+2π+2π] Cycloaddition Reaction of Norbornadiene
Authors: Tabushi Iwao , Yamamura Kazuo , Yoshida Zen-ichi , Togashi Atsushi
Published: July 2006

[2π+2π+2π] cycloaddition reaction of cis- or trans-disubstituted olefinic dienophiles (4a–4e) to bicyclo[2.2.1]hepta-2,5-diene (1, norbornadiene) was found to be stereospecific. The cycloadducts obtained, 4,5-disubstituted tetracyclo[4.2.1.0.2,903,7]nonane (5,6) conserved the original stereochemistry in the dienophiles, strongly suggesting the presence of homo-conjugation in 1. A striking contrast between cycloaddition reaction of quadricyclane (a valence bond isomer of 1) and that of norbornadiene was understood by application of the principle of orbital symmetry conservation to these cycloadditions.
Kinetic Studies of the Thiol-catalyzed Rearrangement of N-Phenylsulfonyl Thione S-Imide
Authors: Tamagaki Seizo , Sakaki Keishi , Oae Shigeru
Published: July 2006

The N-phenylsulfonyl thione S-imide(I) of 1,2-dithiole-3-thione reacted catalytically with various thiols to afford the corresponding rearranged N-phenylsulfonyl-1,2-benzodithiole-3-imine(II) with the extrusion of the elemental sulfur together with a minor amount of reduced benzotrithione. A kinetic study of the rearrangement of I with thiobenzoic acid was performed, and a plausible mechanism is discussed.
The Effect of the Pressure on the Electrical Conductivity of Zinc Sulfate in Water
Authors: Taniguchi Yoshihiro , Watanabe Takashi , Suzuki Keizo
Published: July 2006

The electrical conductivity of ZnSO4 in water was measured at high pressures up to 3000 kg/cm2 and at 25 °C. The dissociation constant of the ion pair (Km) increased with an increase in the pressure. The volume change (ΔV°) accompanying the dissociation was −8.0±0.5 ml/mol at 25 °C. The distance of the closest approach (å) of the ion pair, calculated using the observed Km value and the theoretical equation of Bjerrum, increased with an increase in the pressure. In view of these ΔV° and a values, the ion pair of ZnSO4 was assumed to be of the solvent-separated type. It was also concluded that the number of water molecules separating the ions constituting an ion pair increases with an increase in the pressure.
Kinetic Analysis of the Transitory Overshooting of the H+ Concentration in the Cation-exchange Membrane System
Authors: Takeguchi Noriaki , Horikoshi Isamu , Tanaka Shigeo
Published: July 2006

Overshooting with respect to the H+ concentration was studied quantitatively. Systems of two species of cation and one species of anion were studied for example, the 0.2 M-NaCl (initial, s-side) : Collodion-Polystyrene sulfonic acid membrane: 0.02 M-NaCl+0.002 M-HC1 (1-side, constant). The volume of the 1-side solution was greatly larger than that of the s-side solution. The composition of the former was not altered measurably by the transport of ions across the membrane. Because the cation-exchange membrane used was not highly selective, both cation and anion were permeable. The final composition of the s-side solution became equal to the composition of the 1-side solution. In the course of changes toward the final equilibrium, the H+ or HCl concentration temporarily reached far above the final value. An analytical interpretation with two parameters was given, in which the concentration of the most slowly movable ion in the membrane, Cl−, was assumed to decrease monotonously. Moreover, the concentration of next slowly movable ion, Na+, was assumed to change as a result of the force which tends to bring the system toward the imaginary Donnan equilibrium. The Na+concentration at the imaginary Donnan equilibrium toward which the s-side solution is approaching at any given instant was obtained as follows. The (H+ concentration)/(Na+ concentration) ratio at the equilibrium is the same as the corresponding ratio in the 1-side. Moreover, the total concentration of H+ and Na+ at the imaginary Donnan equilibrium is equal to the existing Cl− concentration in the s-side solution.
Preparation and Stereochemistry of the Cobalt(III) Complexes with N,N′-Polymethylenedi(salicylideneamine) and Its Related Compounds
Authors: Ebina Fujio , Kyuno Eishin , Uehara Akira , Tsuchiya Ryokichi
Published: July 2006

Preparation of two series of the cobalt(III) complexes, Na[Co(CN)2(SB)] and [Co(acac)(SB)], was carried out. CN, acac and SB respectively refer to cyanide anion, acetylacetonate anion and the quadridentate Schiff base anion, N,N′-polymethylenedi(salicylideneamine), N,N′-polymethylenedi(α-methylsalicylideneamine) or N,N′-polymethylenedi(2-hydroxy-1-naphthylmethyleneamine). Efforts to obtain Na[Co(CN)2(SB)] only containing the last Schiff base were unsuccessful. It was concluded from their PMR spectra that, for the dicyano complexes, the structure changes from a trans-form to a cis-one via a distorted trans-form, whereas for the acetylacetonato complexes, it changes from a distorted cis-β-form to an undistorted one with an increase in the length of carbon chain in the bridged polymethylene group of the Schiff bases.
Autoxidation of Atactic Polypropylene and Related Alkanes. Rates and Reactivities toward Peroxy Radicals
Authors: Niki Etsuo , Kamiya Yoshio
Published: July 2006

Rates of autoxidations of atactic polypropylene, polystyrene, and several alkanes in solution initiated by azobiscyclohexanecarbonitrile were measured at 90 °C in the absence and presence of added hydroperoxide and the reactivities toward tert-butylperoxyl and tetralylperoxyl radicals were measured. Atactic polypropylene was found to be oxidized faster than expected from the related alkanes. On the other hand, polystyrene was quite resistant to autoxidation. The relative reactivities of secondary and tertiary hydrogens toward t-butylperoxyl radical were obtained as 1: 9.7 and that for primary hydrogen was estimated to be quite small. The observed reactivity of 2,2,4-trimethylpentane was much smaller than the calculated reactivity from the results of simple alkanes, whereas the observed reactivity of atactic polypropylene was higher than the calculated one. The high reactivity of atactic polypropylene for oxidation and toward peroxyl radicals was interpreted as being due to a fast intramolecular propagation. Tetralylperoxyl radical was 3.6 times as reactive as t-butylperoxyl radical toward both atactic polypropylene and 2,6,10,14-tetramethylpentadecane.
An MO Theoretical Investigations of the Electronic Spectra of Divalent Sulfur Compounds
Authors: Sakai Hideki , Yamabe Tokio , Kato Hiroshi , Nagata Shinichi , Fukui Kenichi
Published: July 2006

The singlet transition energies and oscillator strengths of several divalent sulfur compounds are calculated by the semi-empirical ASMO–SCF method. It is shown that the UV absorption bands with transition energies of 5–6 eV observed in these sulfur compounds can be assigned to n-σ1*, n-σ2*, or σ-σ1*, implying that the 3d orbitals of the sulfur atom do not play an important role in these electronic transitions or may contribute absorption bands with higher transition energies.
Aromatic Substitution of Olefins. XXII. Unusual Reaction of p-Bromostyrene with Benzene in the Presence of Palladium(II) Acetate
Authors: Tanaka Hidetsugu , Fujiwara Yuzo , Moritani Ichiro , Teranishi Shiichiro
Published: July 2006

The reaction of p-bromostyrene with benzene in the presence of palladium(II) acetate gave unexpected bibenzyl (2) and trans-stilbene (3) in 12% and 5% yields respectively, in addition to the usual substitution product (1, 47%). This result shows that dehalogenation and subsequent hydrogenation accompany the aromatic substitution of olefins when both iodides and bromides are used.
Studies of the π→π* Absorption Bands of α-Santonin
Authors: Kuboyama Akira , Sato Yoshikuni , Kobayashi Fumio
Published: July 2006

The π→π* S–S absorption spectra of α-santonin in solutions up to the vacuum UV region were obtained. Based on the results of the MO calculations, the observed four π→π* bands of α-santonin could be favorably assigned.
Extinction Coefficients of Maleate and Fumarate Radical Anions and Relative Yield of cis-trans Isomerization in Methanol Glass at 77 K
Authors: Torikai Ayako , Nakano Fumio , Fueki Kenji , Kuri Zen-ichiro
Published: July 2006

The photoisomerization of the γ-rayinduced maleate radical anion (DEM−) to the fumarate radical anion (DEF−) has been studied. The molar extinction coefficients of DEM− and DEF− have been determined to be 2.43×104 1 mol−1 cm−1 and 3.40×104 1 mol−1 cm−1 respectively. The yield of the isomerization from DEM− to DEF− is found to be 0.95.
The Phase Transition of Bismuth(III) Oxide Prepared by the Thermal Decomposition of Bismuth Sulfate
Authors: Matsuzaki Ryoko , Masumizu Hagio , Saeki Yuzo
Published: July 2006

The phase transitions of α-Bi2O3 prepared by the thermal decomposition of Bi2(SO4)3 on heating and cooling are revealed. The phase transition on cooling is remarkably affected by the existence of a small amount of SO4, such as 0.05%, in the Bi2O3.
A Kinetic Study on the Complex Formation of Iron(III) with o-Cresolsulfonphthalein: A Quinoidal Complex
Authors: Nakayama Hiroaki , Fujimoto Masatoshi
Published: July 2006

The kinetics of the 1: 1 complex formation of Fe(III) with o-Gresol Red is studied. The reaction scheme is quite different from that for the monophenolato complexes of Fe(III), and interpreted by the formation of a quinoidal complex.
The ESR Spectra of the Anthanthrene and Binaphthylene Dioxide Cation-radicals
Authors: Ikegami Kôichi , Matsunaga Yoshio , Osafune Kazuteru , Osawa Eiji
Published: July 2006

The ESR spectra of the anthanthrene and binaphthylene dioxide cation-radicals were recorded and analysed.
On the Trimorphism of 7-Hydroxy-3-(p-methoxyphenyl)-4,6-dimethyl-1-indanone
Authors: Takatori Masayuki , Kanomata Kazuko
Published: July 2006

The reaction of 2′-hydroxy-4-methoxy-3′,5′-dimethylchalcone with anhydrous AlCl3 in benzene gave three kinds of crystals having different melting points. It is concluded that the crystals are three modifications of 7-hydroxy-3-(p-methoxyphenyl)-4,6-dimethyl-1-indanone on the basis of their mutal transformations, IR spectra and X-ray analysis.
The Synthesis of the Benzofuro[2,3-b]benzofuran Derivative
Authors: Nanbu Mutsumu , Momonoi Kaishû , Oguro Susumu , Kawase Yoshiyuki
Published: July 2006

The synthesis of 2,9-dimethoxybenzofuro-[2,3-b]benzofuran from its 5a,10b-dihydro-compound was carried out by bromination with N-bromosuccinimide, followed by dehydrobromination. The attempted preparation of 2,9-dimethyl-, 2,9-dichloro-, and 2,4,7,9-tetrachloro-derivatives was unsuccessful.
α-(3-Phenoxymethyl-7-oxo-4-thia-2,6-diazabicyclo[3,2.0]hept-2-ene-6-yl)-α-isopropenylacetates, Useful Intermediate from Penicillin to Cephalosporin
Authors: Tanida Hiroshi , Muneyuki Ryonosuke , Tsushima Tadahiko
Published: July 2006

Reaction of α-[2-(Benzothiazol-2-yl)-dithio-3-phenoxyacetamido-4-oxoazetidin-1-yl]-α-isopropenylacetates with phosphorus pentasulfide afforded the title compound. The first step in this reaction is suggested as an intramolecular nucleophilic attack of the thioamide function, initially resulted from the 3-acetamido groups, towards the disulfide-sulfur at the 2 position.
The Triplet State of Acenaphthenequinone Crystals Studied by Means of Zeeman Spectroscopy
Authors: Sano Mizuka , Narisawa Takatoshi , I’haya Yasumasa J
Published: July 2006

The origin peak for the lowest singlet-triplet absorption transition of acenaphthenequinone crystals has been observed at 17981.7 cm−1 at 4.2 K. From the direction of the polarization and the Zeeman intensity pattern at 50 kOe, the lowest triplet-state configuration is identified as 3B1(nπ*). The transition to the state from the ground state gains its intensity from the z-polarized 1A1(ππ*)–1A1 transition through the y-component in the spin-orbit interaction.
Apparent Molal Volumes of n-Alkylammonium Chlorides and Sodium n-Alkanecarboxylates in Dilute Aqueous Solutions
Authors: Sakurai Masao , Komatsu Tsuyoshi , Nakagawa Tsurutaro
Published: July 2006

The densities of dilute aqueous solutions of two homologous organic salts, RNH3Cl and RCOONa, where R varies from H to n-octyl, have been measured at 5, 25, and 45 °C using a buoyancy technique. The apparent molal volumes, φv, of the salts and the limiting partial molal volumes, \barV°, of the individual ions have been evaluated. The contributions of a methylene group to the partial molal volume, \barV°(CH2), as estimated from the \barV° data for longer-chain salts, are nearly the same for both series: approximately 15.3, 15.9, and 16.5 ml/mol at 5, 25, and 45 °C respectively. Compared to these values, on the other hand, the \barV°(CH2) estimated for shorterchain RNH3Cl is larger and that for shorter-chain RCOONa is smaller. The second derivative of the \barV° with respect to the temperature, ∂2\barV°⁄∂T2, which is often regarded as a useful measure of structural effects, is almost independent of the chain length for longer-chain homologues. The concentration dependence of φv does not always vary in a regular manner with the chain length. The present results suggest that the volumetric behavior of aqueous organic electrolyte solutions is more complicated than has previously been believed.
The Reaction of 3H-1,2-Benzodithiole-3-thione with Diphenyldiazomethane
Authors: Tamagaki Seizo , Ichihara Ryoichi , Oae Shigeru
Published: July 2006

3H-1,2-Benzodithiole-3-thione (35S=C<) reacted with diphenyldiazomethane in the presence of copper-(II) acetylacetonate to afford the corresponding 4,5-benzo-3-diphenylmethylene-1,2-dithiole with a predominant extrusion of the exocyclic sulfur atom, while with its selenium analog the exclusive loss of in-ring sulfur was observed, resulting in the formation of the selenium-migrated 4,5-benzo-3-di-phenylmethylene-1,2-thiaselenole.
Infrared and Raman Spectra and Rotational Isomerism of 1,4-Pentadiene
Authors: Inagaki Fuyuhiko , Sakakibara Masaaki , Harada Issei , Shimanouchi Takehiko
Published: July 2006

Rotational isomerism of 1,4-pentadiene has been studied. Normal frequencies have been calculated for the low frequency vibrations of four possible rotational isomers. From the change in the spectra in the gaseous, liquid, glassy, and solid states, it has been concluded that the two skew-skew forms (SS and SS′) and the cis-skew form (CS) are stable in the liquid and gaseous states, the SS and SS′ forms coexist in the glassy state, and only the SS form remains in the solid state. It has also been found that the energy difference among the three isomers in liquid state is not appreciably large.
Presumptive Structures of Activated Complexes of Polarographic Redox Reactions of Unsaturated Organic Compounds. I. Polarographic Reductions of Aromatic Hydrocarbons, Aromatic Aldehydes, and Quinones
Authors: Ueda Yo , Ono Yukio
Published: July 2006

Activated complexes of the polarographic reductions of unsaturated organic compounds were assumed to be formed by the interaction of the π-molecular orbital of each compound with a hypothetical atomic orbital of the electrode employed. Linear correlations were obtained between the mutual differences in the polarographic half-wave reduction potentials of a series of unsaturated organic compounds and the respective differences in the π-stabilization energies calculated on the basis of the presumed structures of activated complexes. These linear relationships were considered to lend experimental support to the propriety of the presumed structures of the activated complexes of the polarographic reductions of unsaturated organic compounds.
Analysis of the Elution Curve in Eluting Lutetium from Cation-Exchanger with α-Hydroxyisobutyric Acid
Authors: Kubota Masumitsu
Published: July 2006

The elution behavior of lutetium from a cation-exchange column with α-hydroxyisobutyric acid solution (pH 3.77) was studied as a function of column distribution ratio of lutetium, flow rate, temperature and amount of lutetium. The elution curve fitted the normal distribution when the flow rate was smaller than 40 cm hr−1 for 0.14 M of the eluant, 60 cm h−1 for 0.12 M and 120 cm h−1 for 0.10 M. However, the normal distribution and constancy of the peak position could not be maintained when the amount of lutetium exceeded 200 μg cm−2. Within the range 15–35 °C, the peak position appeared late and the elution curve became sharper with temperature rise, but the diffusion coefficients remained constant. The value of the height equivalent to the theoretical plate was determined from the position and width of the elution peak which varied as a function of the flow rate. The diffusion coefficients of lutetium ions in the ion-exchange resin and the solution were calculated to be 2.6×10−7−6.4×10−9λ″ cm2s−1 and 4.2×10−5λ″ cm2s−1, respectively, according to Glueckauf’s theoretical equation, where λ″ is the column distribution ratio of lutetium ions. The experimental results make it possible to construct an elution curve for any column distribution ratio of lutetium in the range 2–20, temperature and flow rate.
The Preparation of Several Copper(I) and Silver Polyfluoroalkanethiolates and of Polyfluoroalkyl Aryl (or Alkyl) Sulfides
Authors: Kitazume Tomoya , Ishikawa Nobuo
Published: July 2006

2,2,4,4-Tetrakis(trifluoromethyl)-1,3-dithietane (1) in the KF-DMF system was treated with hexafluoropropene in the presence of CuBr to give copper(I) 1,1,2-tris(trifluoromethyl)tetrafluoropropanethiolate (4). A similar reaction of 1 with alcohols in the presence of CuBr or AgNO3 gave copper(I) (6) and silver 1-alkoxy-1-trifluoromethyl-2,2,2-trifluoroethanethiolate (7) respectively. These copper(I) and silver polyfluoroalkanethiolates condensed with aryl or alkyl iodides to afford 1,1,2-tris(trifluoromethyl)-tetrafluoropropyl (8) and 1-alkoxy-1-trifluoromethyl-2,2,2-trifluoroethyl aryl(or alkyl) sulfides (9).
Isolation and Circular Dichroism of the Isomers of Dicyanobis[(R,R)-1,2-cyclohexanediamine] and bis[(S)-propylenediamine]cobalt(III) Complexes
Authors: Kashiwabara Kazuo , Yamanaka Toshimasa , Saito Kazuo , Komatsu Naoto , Hamada Nobuhiro , Nishikawa Hiroaki , Shibata Muraji
Published: July 2006

Three isomers of trans- and cis-[Co(CN)2{(R,R)-1,2-cyclohexanediamine}2]+ and five isomers of the corresponding (S)-propylenediamine complexes have been isolated by chromatography with Dowex 50W-X8 and SP-Sephadex columns, their geometrical structures being assigned on the basis of the ligand field absorption and PMR spectra. Isomers of cis-[Co(CN)2{(S)-propylenediamine}2]Cl, which have different placement of methyl groups of (S) -propylenediamine, gave different methyl PMR resonances with different chemical shifts. The absolute configuration of the isomers was determined from the circular dichroism in the first spin-allowed d-d and the charge transfer band region. The configurational and the vicinal effect have been discussed.
Photochemical Reactions between Dibromomaleic Anhydride and N-Phenylpyrrole
Authors: Matsuo Taku , Mihara Satoru
Published: July 2006

With the irradiation of dibromomaleic anhydride and N-phenylpyrrole, photosubstitution and photocyclization took place in succession to yield pyrrolo[1,2-a]quinoline-4,5-dicarboxylic anhydride as the final product. On the basis of energy-transfer experiments, both of the reactions were concluded to proceed via triplet species. Solvent effects were carefully examined and the presence of polar reaction intermediates was proposed to account for the solvent-dependent deactivation process.
An Alternative Synthesis of (+)-1,7-Dimethyl-4-endo-isopropyl-8-syn-(2-hydroxyethyl)bicyclo[3.2.1]oct-6-ene, the Key Intermediate for the Synthesis of (+)-Sativene and (+)-Cyclosativene
Authors: Hagiwara Hisahiro , Miyashita Masaaki , Uda Hisashi , Yoshikoshi Akira
Published: July 2006

The title compound, the key intermediate for the synthesis of (+)-sativene and (+)-cyclosativene, has been synthesized through the alternative route starting with (−)-carvone.
The Reaction of Open-chain Unconjugated Dienes with Palladium Acetate. Dependence of the Products on Disposition of the Two Double Bonds
Authors: Adachi Nobuo , Kikukawa Kiyoshi , Takagi Makoto , Matsuda Tsutomu
Published: July 2006

The reaction of open-chain unconjugated dienes with palladium acetate in acetic acid was investigated with particular reference to the behavior of the two double bonds in the course of the acetoxylation. 1,5-Hexadiene produced 3-acetoxymethylenecyclopentane (64%), but 2,6-octadiene bearing two terminal methyl groups gave open-chain acetoxylated products: 3-acetoxy-1,6-octadiene (46%) and 7-acetoxy-2,5-octadiene (47%). The reactions of 1,6-heptadiene and diallyl ether are found to proceed via abnormal anti-Markovnikov addition to afford cis and trans 1-acetoxy-1,6-heptadienes (63%) and γ-acetoxyallyl allyl ethers (84%), respectively. No participation of the second double bond has been observed in the reaction of 1,7-octadiene. The behaviors of these dienes to palladium acetate can be reasonably explained by assuming the formation of π,σ-palladium species possessing a stable pseudo-six membered ring.
Absolute Stereochemistry of Farfugin A
Authors: Tada Masahiro , Moriyama Yoshihiko , Tanahashi Yoshiaki , Takahashi Takeyoshi
Published: July 2006

4,6-Dimethylcoumarin (3) was converted to an enantiomer (1b) of farfugin A, via a levorotatory carboxylic acid (5b). This led to the absolute configuration (1a) for farfugin A.