bluuebunny/crossref_metadata_2025 huggingface dataset:
The Molecular Structure of Dimethyl Sulfide
Authors: Iijima Takao , Tsuchiya Shuzo , Kimura Masao
Published: July 2006

The gas-phase molecular structure of dimethyl sulfide, (CH3)2S, has been investigated by means of electron diffraction. By a joint analysis of the diffraction results and the spectroscopic moments of inertia by Pierce and Hayashi, the structure parameters, the distances in rg and the angles in \varphiav, were determined (with parenthesized limits of error) to be as follows: S–C=1.807(2) Å, C–H=1.116(3) Å, ∠CSC=99.05(4)°, and ∠HCH=109.3(5)°. A tilt of 2.35° and the local C3v symmetry of the methyl groups were assumed. The isotope effects of deuterium substitution were examined, and the DCD angle was found to be larger than HCH in the zero-point average structure.
The Oxidation Activity and Acid-base Properties of V2O5-based Binary Catalysts
Authors: Ai Mamoru
Published: July 2006

The oxidation of cis-2-butene, butadiene, and acetic acid was carried out by using a series of V2O5–XnOm (atomic ratio=9 : 1) catalysts with more than twenty metal oxides (XnOm). The results were compared with the dehydration activity for isopropyl alcohol (IPA), as a measure of acidity, and with the ratio, dehydrogenation activity for IPA/dehydration activity for IPA, used as a measure of the basicity of catalyst. The activity for the oxidation of butadiene and that for the isomerization of butene are correlated with the acidity, and the activity for the oxidation of acetic acid with the basicity of the catalyst. The selectivity to maleic anhydride from butene and butadiene is scarcely influenced by the introduction of metal oxides. Butene is mainly oxidized to acetic acid as a result of C–C fission. The selectivity to acetic acid is enhanced when the catalyst is highly acidic, decreasing with increase in basicity. It is concluded that the introduction of metal oxides into V2O5 modifies the acid-base properties of the catalyst, inducing a change in oxidation activity and selectivity.
Structure of Aqueous Isomeric Butyl Alcohols—Sound Velocity Studies
Authors: Murthy N Manohara , Subrahmanyam S V
Published: July 2006

The effect of isomeric butyl alcohols on the temperature of sound velocity maximum in water (TSVM) was studied using a variable path interferometer working at 3 MHz. The structural contribution to the shift in TSVM, [ΔTstr]exp was evaluated for the butyl alcohols and the results are compared with those obtained from studies on the effect of these solutes on the temperature of adiabatic compressibility minimum and density maximum of water. The results indicate that the butyl alcohols enhance the hydrogen-bonded structure of water at low concentrations and at any given concentration, the order of increasing structural contribution to the shift in TSVM being t-butyl>s-butyl>isobutyl>butyl alcohols. The structural propensities of the butyl alcohols as revealed by TSVM studies are in line with the information obtained from the temperature of adiabatic compressibility minimum and density maximum studies. The results of the present study indicate that TSVM studies are useful in understanding the solution structure in aqueous mixtures.
The Synthesis of Greigite from a Polysulfide Solution at about 100 °C
Authors: Wada Hiroaki
Published: July 2006

Favorable synthesis conditions for greigite are examined in FeSO4·(NH4)2SO4–Na2S–Na2Sx systems at about 100 °C. It has been found that greigite formation is influenced by the pH adjustment and by the addition of sulfur. When the final pH is about 6.0 and the dissolved iron concentration is in the 10−3–10−1.5 M range, greigite is synthesized as a single phase. The unit-cell dimensions of greigite range from 9.840 to 9.877 Å, corresponding to variations in compositions between 45.4 and 42.9 atomic % Fe. The formula of synthetic greigite is represented as Fe3+xS4 (x=0–0.4).
One-dimensional System of Square-planar Bis(1,2-dicyanovinylene-1,2-dithiolato)metal Complexes. I. The Crystal Structure of [(C4H9)4N]2[Ni(mnt)2] and [(C2H5)4N][Ni(mnt)2]
Authors: Kobayashi Akiko , Sasaki Yukiyoshi
Published: July 2006

X-Ray crystal structure analyses of [(C4H9)4N]2[Ni(mnt)2] (I) and [(C2H5)4N][Ni(mnt)2] (II) {mnt: 1,2-dicyanovinylene-1,2-dithiolato C4N2S22−} have been carried out from the viewpoint of one-dimensional system. Crystals of (I) belong to triclinic system: a=12.360(6), b=11.138(12), c=9.833(9) Å, α=118.43(9), β=92.05(6), γ=91.91(6)°, space group P\bar1 with Z=1. The compound (II) forms monoclinic crystals, P21/a: a=20.018(18), b=16.079(9), c=7.118(6) Å, β=110.43(6)°, Z=4. Both structures, solved by the heavy-atom method, have been refined anisotropically by least-squares procedure to R=0.049 and 0.050 for (I) and (II), respectively. The bond distances of diamagnetic Ni(mnt)22− anion and paramagnetic Ni(mnt)21− anion are compared. A columnar structure was found in the structure of (II). The Ni(mnt)21− ions form a diadic unit, that is a repeating unit of two anions, within the columns. The electrical conductivity data are measured along the direction parallel to the Ni(mnt)21− stacks in the temperature range from room temperature to 373 K. This compound behaves as a semiconductor in this temperature range.
The Study of Thermochemical Hydrogen Preparation. III. An Oxygen-evolving Step through the Thermal Splitting of Sulfuric Acid
Authors: Dokiya Masayuki , Kameyama Tetsuya , Fukuda Kenzo , Kotera Yoshihide
Published: July 2006

The thermal decomposition of sulfuric acid is used as a step in the oxygen evolution in some thermochemical water-splitting cycles. The catalytic activity of metal oxides was studied in an attempt to find some suitable catalysts for sulfuric acid decomposition. The catalytic activity of SiO2, Al2O3, ZnO, CuO, NiO, CoO, Fe2O3, MnO, Cr2O3, V2O5, TiO2 was measured at high temperatures (800–870 °C and at atmospheric pressure. Iron(III) oxide was found to have the highest activity as a catalyst. Low catalytic activity was observed for the oxides (Al2O3, ZnO, NiO, CoO, MnO) which change to their sulfates under the present reaction conditions. Since the reaction conditions were very severe (more than 800 °C and in the presence of steam), a rapid decrease in both the specific surface area and the catalytic activity was observed. In order to avoid these disadvantages and in order to prepare practically useful catalysts, iron(III) oxide was pelletized and sintered (1000 °C, 6 h). Upon this procedure, this catalyst showed an almost constant activity for 120 hours’ reaction.
Synthesis and Absorption Spectra of the [Co(O–O)2(py)2]-type Complexes
Authors: Ida Yayoi , Fujinami Shuhei , Shibata Muraji
Published: July 2006

Five bis (dicarboxylato)bis(pyridine)-type complexes, trans-[CoCO3ox(py)2]−, trans- and cis-[Co(ox)2(py)2]−, and trans- and cis-[Co(mal)2(py)2]−, have been isolated as crystals and characterized on the basis of the absorption spectra, the PMR spectra, etc. The trans isomers of the carbonatooxalato and bis(oxalato) complexes reveal spectra similar to that of the trans-[Co(CO3)2(py)2] complex synthesized previously; the splittings of the absorption bands are not observed in the I bands, but are observed in the II bands. On the other hand, the trans isomer of the bis(malonato) complex reveals no splittings in either the I band or the II band. The assignment of these absorption bands has been made from considerations based on the Angular Overlap Model.
Association Constants of Optically Active [Co(en)3]3+ with (+)-Tartrate and Fumarate Ions Determined from the Kinetic Data of Hydrogen-Deuterium Exchange
Authors: Fujita Miho , Yamatera Hideo
Published: July 2006

The hydrogen-deuterium exchange rates of Λ- and Δ-[Co(en)3]3+ were measured in D2O solutions containing (+)-tartrate ions. From the kinetic data, the ion-association constants of the Λ- and Δ-isomers with (+)-tartrate ions were determined to be 40 and 32 (I=0.1) respectively. Similar measurements with fumarate resulted in the association constant of 16 (I=0.1).
The Synthesis of Peptides by Means of Proteolytic Enzymes
Authors: Isowa Yoshikazu , Ohmori Muneki , Ichikawa Tetsuya , Kurita Hideaki , Sato Masanari , Mori Kaoru
Published: July 2006

Nagarse, papain, pepsin and thermolysin were found to catalyze the peptide bond formation between two amino acids or peptides, one protected with a suitable group at the amino group and the other at the carboxyl group. Experiments with various combinations of amino acids and dipeptides show specificity in the catalytic action in varying degree which depending on the nature of the enzyme. Since the condensation takes place efficiently under mild conditions, this method opens up a useful way for the synthesis of peptides.
The Enzymatic Synthesis of Protected Valine-5 Angiotensin II Amide-1
Authors: Isowa Yoshikazu , Ohmori Muneki , Sato Masanari , Mori Kaoru
Published: July 2006

An example of the use of proteolytic enzymes to facilitate the peptide synthesis by fragment condensation is provided for the preparation of protected valine-5 angiotensin II amide-1 using t-butoxycarbonylpeptides as a carboxyl component and a peptide ethyl ester as an amine component. The proteolytic enzymes used are papain, nagarse (subtilisin BPN′) and microbial metalloenzyme isolated from St. caespitosus. Papain-catalyzed condensation reaction afforded the corresponding oligopeptide in the ester form, whereas nagarse and microbial metalloenzyme-catalyzed condensation reactions afforded the products in the carboxyl free form. Assignment of the product was made on the basis of a comparison of physical properties with those of the peptide prepared by the solution method.
OH− as a Possible Cause of the Electron-donor Property of the ZrO2–TiO2 System
Authors: Esumi Kunio , Shimada Hiroaki , Meguro Kenjiro
Published: July 2006

The electron-donor property of the zirconia-titania system was investigated by means of the adsorption of TCNQ. The TCNQ anion radicals were formed as a result of electron transfer to adsorbed TCNQ from the zirconia-titania surface. The radical concentration on the zirconia-titania system decreased with a increase in the titania content, reached a minimum point at a titania content of 38%, and then increased with the further increase in the titania content. This behavior can explained by the relative amount of OH− sites, which must be proportional to both, or either one, the relative contents of the pure zirconia phase or the pure titania phase existing on the surface of the zirconia-titania system.
Electrochemical Fluorination of Ethanethiol
Authors: Baba Hajime , Kodaira Kazuo , Nagase Shunji , Abe Takashi
Published: July 2006

The electrochemical fluorination of ethanethiol has been carried out. A number of new fluoroalkyl sulfur compounds have been isolated and characterized.
The Synthesis of 3-Substituted Tropilidenes by the Dehydration of 1-Substituted 2,6-CycloheptadienoIs. A New Unambiguous Route
Authors: Takeuchi Ken’ichi , Maeda Takashi , Okamoto Kunio
Published: July 2006

3-Alkyl-, 3-aryl-, and 3-deuteriotropilidenes are prepared in 21–29% yields by the dehydration of the corresponding 1-substituted 2,6-cycloheptadienols with boric acid. The present method provides an unambiguous route to the title compounds.
The Effects of Solvents on the Electronic Absorption Spectrum of Sodium 4-Nitrophenoxide in the Presence of 15-Crown-5 Ether
Authors: Ueji Shinichi , Kitadani Masayuki
Published: July 2006

The electronic absorption spectrum of sodium 4-nitrophenoxide was determined in 21 solvents of varying polarities by the aid of the ability of 15-crown-5 ether to solubilize the salt in nonpolar solvents. These spectra showed a marked difference between hydroxylic solvents and nonhydroxylic solvents. A possible interpretation for this difference is presented.
The Interaction of Acridine Orange with Poly(S-carboxymethyl-l-cysteine)
Authors: Imae Toyoko , Ikeda Shoichi
Published: July 2006

The interaction of Acridine Orange with poly(S-carboxymethyl-l-cysteine) has been investigated by observing the solubility behavior, absorption spectra, and circular dichroism of the mixture. When the dye is added to aqueous solution of the polymer, the mixture is homogeneous at higher pH, but precipitation takes place at lower pH; the threshold pH ranges from 3.5 to 6, depending on the mixing ratio. For [P]/[D] 1 or less, the mixture is again homogeneous at very low pH between 4 and 2, when no salt is added. Various type of circular dichroism are induced for the homogeneous solutions, which are characteristic of the bound dye species on the polymer and the structure of dye–polymer complex. The binding of dye with the polymer is mainly caused by electrostatic effect, and the solubility of the mixture is interpreted by considering the ionization of polymer and the binding of dye to the polymer.
PMR Studies of the Phase Transition in N,N,N′,N′-Tetramethyl-p-phenylenediamine (Wurster’s Blue) Perchlorate
Authors: Inoue Motomichi , Kuramoto Hiroyoshi , Nakamura Daiyu
Published: July 2006

The powder PMR spectra of [TMPD]+(ClO4)− were recorded in the temperature range 110–300 K. The spectra observed above 140 K consist of two widely separated simple absorption curves of intensity ratio approximately equal to 3 : 1. Spin densities on the carbon and nitrogen atoms of the cation radical were evaluated from the observed field shift ascribable to the Fermi contact interaction. The spin density distribution of the radical ion changes at the transition temperature of 189 K.
Reactions of Benzyne–Silver Cation Complex with Substituted Benzenes
Authors: Tabushi Iwao , Yamada Hidenori , Yoshida Zenichi , Oda Ryohei
Published: July 2006

The presence of silver perchlorate changed the products in the reaction of benzyne with substituted benzene (anisole, toluene, chlorobenzene or methyl benzoate) to increase biphenyl and/or benzylidyne trifluoride derivatives by the sacrifice of benzobicyclo[2.2.2]octatriene derivatives. In the case of toluene, o-methylbiphenyl (15) and 6-methylbenzocyclooctene (14) were considered to be formed via common intermediate. These results were well explained by an assumption of benzyne–silver cation complex. From competition experiments, it was concluded that benzyne-silver cation complex assumed here had a stronger electrophilicity than benzyne itself.
Linear-sweep Voltammetry and the Simultaneous Determination of Purine Bases and Their Nucleosides in the Glassy Carbon Electrode
Authors: Yao Toshio , Wasa Tamotsu , Musha Soichiro
Published: July 2006

Adenine, adenosine, guanine, and guanosine were voltammetrically oxidized in a glassy carbon electrode in aqueous solutions, but at different potentials. In general, the nucleosides were oxidized at more positive potentials than their bases. The bases and their nucleosides were strongly adsorbed on the surface of the glassy carbon electrode at the pH values around neutrality, so that the concentration vs. anodic peak current curves were not linear. The adsorption on the electrode was very dependent on the pH, and at pH values below 4 good linear relationships were observed between the anodic peak current and the concentration. The differences between the peak potentials of each of the purine bases and their nucleosides were most pronounced at pH 2–4. Consequently, it was possible to determine simultaneously both in mixtures of the purine bases and their nucleosides by using Britton-Robinson buffer as a supporting electrolyte in the pH range of 2–4. The proposed method is simple and rapid, since no prior treatment or separation procedure is required.
Reaction of Ru(II)-EDTA in Sodium Formate–Formic Acid Solutions
Authors: Shimizu Kunio
Published: July 2006

When [RuIII(Hedta)(H2O)] was reduced at mercury electrode in sodium formate–formic acid solutions, the reduced species gradually became polarographically inactive. The final product of the deactivation reaction was isolated and identified as Na2[RuII(edta)(CO)]. The kinetics follows the second-order rate equation, −dc1⁄dt=kobsd c1 c2, where c1=[[RuII(Hedta)(H2O)]−]+[[RuII(edta)(H2O)]2−] and c2=[HCOO−]+[HCOOH]. The kobsd value was found to be expressed by k [H+]/(KA+[H+]), where KA (=3.28×10−4 mol dm−3) and KR (=6.92×10−4 mol dm−3) are the acid-dissociation constants of formic acid and [RuII(Hedta)(H2O)]−, respectively, with k=1.01×10−5 s−1 at 25 °C (ionic strength=0.5 mol dm−3). Several possible mechanisms for the reaction were discussed. Probably the reaction proceeds through the formation of an intermediate involving one formate anion followed by dehydration and rearrangement.
Restricted Rotation Involving the Tetrahedral Carbon. XX. Barriers to Rotation and 13C NMR Spectra of 9-(2-Alkylphenyl)fluorene Derivatives
Authors: Nakamura Mikio , Nakamura Nobuo , Oki Michinori
Published: July 2006

A series of 9-(2-alkylphenyl)fluorene derivatives are prepared and their internal rotation about the C9–Car bond is examined. Those which have a methyl, an ethyl, or an isopropyl group in 2′ position exist as a mixture of sp and ap forms, showing coalescence phenomena in the NMR spectra at high temperatures. The barriers to rotation of these compounds are obtained by the usual DNMR method. 9-(2-t-Butylphenyl)fluorene, in contrast, is found to exsist exclusively as an sp form and thus the barrier to rotation must be determined by measuring the rates of conversion from the unstable ap form which is successfully obtained by the protonation of the corresponding lithium fluorenide at low temperatures. The barriers to rotation of the compounds are alike except for the t-butyl compound. The difference is explained in terms of the conformation of the alkyl group in the ground and the transition state for rotation. The 13C NMR data also exhibit a large steric interaction between the alkyl group and the fluorene ring.
The Photosensitized Oxygenation of Furanoeremophilanes. II. The Preparation and Stereochemistry of the Isomeric Hydroperoxides and the Corresponding Lactones from Furanofukinin and Furanoeremophilane
Authors: Naya Keizo , Nogi Noboru , Makiyama Yasuo , Takashina Hideo , Imagawa Takashi
Published: July 2006

The dye-sensitized oxygenation of furanofukinin, and furanoeremophilane, in methanol gave, quantitatively, crystalline mixtures of two isomeric hydroperoxides each consisting of a pair of 8α-methoxy-12β-hydroperoxy and 8β-methoxy-12α-hydroperoxy derivatives respectively. The hydroperoxides were readily transformed to the corresponding lactones with acetic anhydride-pyridine through dehydration. The stereochemistry of the hydroperoxides and the corresponding lactones has been elucidated by spectral and chemical methods according to a previously outlined generalization. Further, furanofukinin, furanoeremophilane, and 8β-hydroxyeremophilenolide, have been synthesized from petasalbin, fukinone, and an epimeric mixture of 8α- and 8β-methoxy lactones, respectively.
The Ethylation of Nucleic Acid-Bases with Triethyl Phosphate
Authors: Tanabe Toshizumi , Yamauchi Kiyoshi , Kinoshita Masayoshi
Published: July 2006

Uracil, thymine, cytosine, adenine, and guanine were alkylated by triethyl phosphate in a homogeneous aqueous phase at 60–80 °C, giving the corresponding ethyl derivatives in considerable yields. The reactivity order on the ethylating site in each base was found to be as follows; uracil, thymine, and cytosine: N-1>N-3; adenine: N-9≈N-3>N-7, N-1; guanine: N-1>N-7>N-3, N-9.
Colloid Titration Behavior of the Maleic Acid–Methyl Vinyl Ether Copolymer
Authors: Kokufuta Etsuo , Iwai Shinji
Published: July 2006

The colloid titration of the maleic acid–methyl vinyl ether (MA–MVE) copolymer with trimethylammonium glycol chitosan iodide (MGCH) was carried out at various pH values. The mechanism of the formation of the polyion complex between the MA–MVE copolymer and the MGCH ions was discussed.
The Formation of the N-bound Hydroxyiminoacetylacetonato Ligand by the Reaction of Nitrosyl in Bis(2,2′-bipyridine)chloronitrosylruthenium(II) with Acetylacetone
Authors: Mukaida Masao , Yoneda Masakazu , Nomura Terunosuke
Published: July 2006

Nitrosyl in [RuCl(bpy)2NO]2+ reacts with Hacac, giving the N-bound hydroxyiminoacetylacetonato ligand(hia, CH3COC(NO)COCH3−) under mild conditions. The reaction product, [Ru(hia)(bpy)2(H2O)]X (X=ClO4, PF6), was characterized on the basis of its IR spectra, including those of the 15N-complex.
The Photochemical Sulfenylation of Hindered Phenols with Diaryl Disulfides
Authors: Fujisawa Tamotsu , Kojima Takakazu
Published: July 2006

The photochemical reaction of diaryl disulfides with 2,6-disubstituted phenols was investigated. The reaction with highly hindered phenols proceeded appreciably upon irradiation with a high-pressure mercury lamp, giving rise to 4-arylthio-2,6-disubstituted phenols. The reaction was initiated by the homolytic scission of the disulfides.
A Simple Method for the Synthesis of 5-Methyloxazolo[4,5-c]quinolin-4(5H)-ones
Authors: Merchant J R , Shirali S S
Published: July 2006

A general and simple method for the synthesis of oxazolo[4,5-c]quinoline-4(5H)-ones by heating 3-amino-4-hydroxy-2-quinolone hydrochloride with aromatic acids in the presence of PPA has been described. The structures are based on spectral and analytical data.
Oxidation of Biphenylene with Ammonium Cerium(IV) Nitrate. A Convenient Route to Biphenylene-2,3-dione
Authors: Sato Masaru , Fujino Harutoshi , Ebine Seiji , Tsunetsugu Josuke
Published: July 2006

Biphenylene was directly oxidized with ammonium cerium(IV) nitrate to give biphenylene-2,3-dione in moderate yield, along with 2-nitrobiphenylene and 3-nitro-biphenylen-2-ol.
Interactions of Calcium Ions with Carbohydrates: X-Ray Diffraction and NMR Spectroscopic Studies on the Potassium Salt and the Calcium Salt of d-Clucaric Acid
Authors: Taga Tooru , Kuroda Yoshihiro , Osaki Kenji
Published: July 2006

The crystal structure of potassium d-glucarate was determined by X-ray analysis. The conformation of the glucaric anion in the potassium salt differs from that of the dianion in the crystal of the calcium salt. The proton magnetic resonance spectra of the solutions of the potassium salt and the calcium salt show that the glucarate solution is an equilibrium mixture of the two conformers observed in the crystals. Studies on the induced shifts by adding europium nitrate to the acidic solution indicate that the europium ions are selectively bound to the potassium type conformer. Calcium sequestant by the glucaric acid in alkaline solutions should occur when calcium ions bind the calcium type conformers in a dianionic state.
Synthesis of New Heptacyclic Propellanes
Authors: Tobe Yoshito , Omura Hirofumi , Kunai Atsutaka , Kimura Koji , Odaira Yoshinobu
Published: July 2006

The heptacyclic propellanes, 8 and 9, having two propellane rings in each molecule, were synthesized by the stepwise photocycloaddition of bicyclo[4.3.0]non-1(6)-en-7-one (1) to cyclohexadiene or cyclooctadiene followed by the Wolff-Kishner reduction of the resulting propellanones 6 and 7. The photosolvolytic behavior of some of the cycloadducts is also described.
Four Isomers of the Bis(ethylenediamine)sarcosinatocobalt(III) Ion: Separation, Identification, and Characterization
Authors: Fujita Miho , Yoshikawa Yuzo , Yamatera Hideo
Published: July 2006

All four possible isomers of the bis(ethylenediamine)sarcosinatocobalt(III) ion, [Co(sar) (en)2]2+, were separated chromatographically on the column of an SP-Sephadex cation exchanger, and their absorption, circular dichroism, and 13C NMR spectra were measured. The more stable pair of isomers were identified as Δ-[Co(S-sar) (en)2]2+ and Λ-[Co(R-sar) (en)2]2+, while the less stable pair were Δ-[Co(R-sar) (en)2]2+ and Λ-[Co(S-sar) (en)2]2+. The Δ-[Co(S-sar) (en)2]2+ isomer in an aqueous solution showed mutarotation which can be ascribed to a change in configuration (epimerization) about the sarcosinato nitrogen atom. In equiribrium at 25°C, the mixture consisted of 84.8% of the Δ(S) isomer and 15.2% of the Δ(R) isomer. From this result, the free-energy difference between the isomers was estimated to be 4.26 kJ mol−1. The presence of the less stable isomers, which were not found by Buckingham et al., was also confirmed by the 13C NMR measurements.
Photochemical Ethoxycarbonylmethylation of Toluene with Ethyl Chloroacetate
Authors: Ogata Yoshiro , Hayashi Eiji
Published: July 2006

UV irradiation of a toluene solution of ethyl chloroacetate under N2 gave an isomeric mixture of ethyl tolylacetates: ortho, 5.2%, meta, 9.6%, para, 0.9% and a trace of diethyl succinate. The reaction under air increased the yields of all the products. Addition of AlCl3 also increased the yields, especially that of ortho; i. e.; 17.9%; meta, 26.5%; para, 10.6%.
Solvent Effects upon Dynamic Behavior of Intramolecular Heteroexcimers
Authors: Okada Tadashi , Saito Takashi , Mataga Noboru , Sakata Yoshiteru , Misumi Soichi
Published: July 2006

Solvent effects upon fluorescence quantum yields, fluorescence rise and/or decay curves of p-(CH3)2NC6H4–(CH2)n–(9-anthryl) (n=1, 2, 3) and p-(CH3)2NC6H4–(CH2)n–(1-pyrenyl) (n=1, 2, 3) have been investigated in detail. It is concluded that the sandwich structure is not necessary for the intramolecular charge transfer in polar solvents and that the mechanism of intramolecular heteroexcimer formation in polar solvents is different from that in nonpolar solvents.
The Structure and Reactions of Imidoyl Triphenylphosphonium Methylides
Authors: Yoshida Hiroshi , Ogata Tsuyoshi , Inokawa Saburo
Published: July 2006

Twenty-five imidoyl triphenylphosphonium methylides III were prepared from triphenylphosphonium methylide and imidoyl chlorides or imidates in moderate yields. The configration of these ylides was assigned on the basis of NMR spectroscopic studies. N-Tosyl substituted ylides showed no reactivity toward aldehydes, whereas N-aryl substituted ylides could be converted easily into α,β-unsaturated ketimines in good yields. The reaction of III with carbon disulfide was also studied.
The Components of Petasites japonicus Maxim. IV. The Structure of Petasitin
Authors: Takagi Ichiro , Tazuke Yasuhito , Naya Keizo
Published: July 2006

Petasitin, a component isolated from a wild variety of Petasites japonicus Maxim., has been shown to be 3α-[(Z)-2-methyl-2-butenoyloxy]-11-hydroxyeremophila-6,9-dien-8-one, and has been synthesized from the known isopetasin by photosensitized oxygenation.
Substituent Effects in the Diels-Alder Reaction of Substituted Benzynes with Hexamethylcyclohexa-2,4-dienone
Authors: Oku Akira , Matsui Akira
Published: July 2006

The Diels-Alder reaction of unsymmetrically substituted benzynes that had been generated from 3-Me-, 4-Me-, 5-Me-, 6-Me-, 3,4-Me2-, 3-NO2-, 4-NO2-, 5-NO2-, and 3-Cl-benzenediazonium-2-carboxylates, with hexa-methylcyclohexa-2,4-dienone gave a mixture of 5- or 6-substituted-1,2,3,4,10,10-hexamethyl-1,4-dihydro-1,4-. ethanonaphthalene-9-one (Type 7) and its 8- or 7-substituted isomer (Type 8). The 7/8 isomer ratios varied from 1.0 to 2.0 depending substantially on the size and the position of substituents of the benzynes and also on the temperature and the solvent. The ratios were the same when two positionally isomeric acids, i.e., 3- and 6-, or 4- and 5-substituted acids, were used as the precursors. Thus, the identity of the benzynes generated from these paired isomeric precursors was proved, ruling out the possibility of an inherent memory effect of the precursors. The factor that controls the isomer ratios is discussed in terms of the steric repulsive interaction between the substituents of benzynes and the gem-dimethyl groups of the dienone.
Backbone Rearrangement of 3β,4β-Epoxyfriedelane. A Formation of Germanicol and Solvent Effects
Authors: Tori Motoo , Tsuyuki Takahiko , Takahashi Takeyoshi
Published: July 2006

In the reaction of 3β,4β-epoxyfriedelane with boron trifluoride etherate in benzene, a backbone rearragement proceeds up to D/E rings, giving germanicol as the main product, together with D:B-friedo-olean-5(10)-en-3β-ol, D:B-friedo-olean-5-en-3β-ol, and β-amyrin. The reaction product ratio of this reaction in various solvents was examined by HPLC.
Photo-induced Electricity Generated by Thin-layer Photogalvanic Cells Containing Thionine and Iron(II) Salt
Authors: Shigehara Kiyotaka , Nishimura Masatoshi , Tsuchida Eishun
Published: July 2006

The photogalvanic effects of thionine and Fe(II) salt systems were studied by use of thin-layer photocells. Three systems of the cell components, i.e., SnO2/thionine–Fe(II) aq/Pt, SnO2/thionine–Fe(II)-gelatinized reagent/Pt, and SnO2/polymeric thionine membrane–Fe(II)/Pt, were compared. The photopotential ΔE and the photocurrent I were the largest in the third system. It was concluded that the excellent ability of the polymeric thionine system to generate the photo-induced electricity is due to the strong electrostatic repulsion between Fe3+ and the semi-species bound to the cationic polymers, since the repulsion diminished the short-circuit in a solution or the bulk-backward reaction with Fe3+. The electron-recycling in a solution took place not only through the transportation of Fe3+ to the cathode, but also through the electron-exchange reaction between Fe2+ and Fe3+  via hydrogen bonds.
The Preparation of Trivalent Metal Chelates with Some N3O3-Type Ligands
Authors: Takahashi Mariko , Takamoto Susumu
Published: July 2006

Iron(III), chromium(III), and cobalt(III) chelates with 1,4,7-triazacyclononane-N,N′,N″-triacetate, 1,4,7-triazacyclodecane-N,N′,N″-triacetate, and 2-(aminomethyl)-2-methyl-1,3-propanediamine-N,N′,N″-triacetate were synthesized and characterized by means of the electronic absorption spectra in an aqueous solution. As they are noncharged chelates with a C3 symmetry, their spectra resemble those of facial tris(glycinato) complexes.
The Formation and Extraction Equilibria of Several Manganese(II) β-Diketonates and Their Trioctyl-Phosphine Oxide Adducts
Authors: Sekine Tatsuya , Murai Ryokichi , Takahashi Kazuhiko , Iwahori Shigehisa
Published: July 2006

From the distribution ratio of manganese(II) between carbon tetrachloride containing various amounts of β-diketone (HA) and trioctylphosphine oxide (TOPO), and an aqueous 1 mol dm−3 perchlorate solution at 25 °C, the formation constants for the aqueous chelates and the TOPO adducts of the MnA2, and the partition constants for the MnA2 chelates were determined. The constants were then compared with those of other divalent metal ions.
Electronic Structures and Spectra of Azulenophenalenes
Authors: Koyanagi Tsuguo , Shin Yuko , Yamaguchi Hiroyuki
Published: July 2006

The ground-state electronic properties and electronic spectra of azuleno [5, 6, 7-cd]phenalene (I) and azuleno[1, 2, 3-cd]phenalene (II), which are isomers of the potent carcinogen benzo[a]pyrene (III), have been investigated by using the SCF screened potential MO CI method in combination with the variable bond-length technique. From the calculated C–C bond lengths and the position dependence of the SCF screened potential, it may be concluded that molecules I, II, and III are all both aromatic and polyolefinic. The electronic spectra of I, II, and III predicted using the screened potential are in better agreement with the experimental values than those calculated using the bare potential.
A Potentiometric Study on Complex Formation of Cadmium(II) and Lead(II) Ions with Ethylenediaminetetraacetic Acid
Authors: Oyama Noboru , Matsuda Hiroaki , Ohtaki Hitoshi
Published: July 2006

The complex formation of cadmium(II) and lead(II) ions with ethylenediaminetetraacetic acid (EDTA) has been studied potentiometrically in a 1.0 M NaClO4 medium at 25.0 °C by using glass and metal–amalgam electrodes. The results were explained in terms of the formation of the complexes of MHqL with q=3, 2, 1, and 0 for both metals. The corresponding formation constants were determined: for the Cd–EDTA system, logβ101=14.25±0.02, logβ111=17.41±0.02, logβ121=19.71±0.02 and logβ131=21.35±0.02; for the Pb–EDTA system, logβ101=16.50±0.05, logβ111=19.78±0.02, logβ121=21.35±0.02 and logβ131=22.50±0.02, where βpqr=[MpHqLr(2p+q−4r)+]/[M2+]p[H+]q[L4−]r and L denotes the unprotonated molecule of EDTA. The protonation constants of unprotonated EDTA were found to be logβ011=8.63±0.02, logβ021=14.99±0.02, logβ031=17.63±0.02, logβ041=19.87±0.02, logβ051=21.54±0.02, and logβ61=22.70±0.02.
Reactions of the Cation Radicals of Aromatic Diamines with Their Parent Molecules or Aliphatic Amines
Authors: Sakata Tadayoshi , Hiromoto Mitsuo , Yamagoshi Tomoko , Tsubomura Hiroshi
Published: July 2006

The chemical reactions of the cation radicals of some aromatic diamines with their parent molecules, aliphatic amines or sodium hydroxide have been studied spectroscopically. In the case of the cation radical of p-phenylenediamine (PPD), the main products are Bandrowski’s base (BB) and PPD, p-benzoquinone diimine being found as an intermediate. This reaction are found essentially to be a disproportionation of PPD+ to BB and PPD in which bases added enhance the reaction rate. The thermodynamical quantities of the initial step of the reaction, proton transfer from PPD+, are estimated and the reaction mechanism is discussed. The reaction of the cation radical of N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD) with triethylamine (TEA) gives the parent molecule, TMPD. This reaction is concluded to be caused by an electron transfer from TEA to TMPD+ followed by a reaction of TEA with a large negative free energy change. The reaction between the cation radical of N,N-dimethyl-p-phenylenediamine and its parent molecule has also been studied.
Mechanism of the Chemiluminescence of Lucigenin. II. The Charge-transfer Structure of Lucigenin and Reduction of 10,10′-Dimethyl-9,9′-biacridinium Dication by Electron Transfer from Nucleophiles
Authors: Maeda Koko , Kashiwabara Toshi , Tokuyama Mizue
Published: July 2006

Lucigenin (10,10′-dimethyl-9,9′-biacridinium dinitrate, DBA2+2NO3−) was found to be a CT complex between DBA2+ and NO3−. In the reaction of lucigenin with several nucleophiles in the absence of molecular oxygen or oxidizing agents the following four types of products were obtained, depending upon the relative power of the nucleophiles to donate electrons to DBA2+: (1) salts of DBA2+ (DBA2+2X−) which are the CT complex between DBA2+ and the nucleophiles, such as Cl−, Br−, SCN−, and I−, (2) the cation radical DBA\underset.+ produced by one-electron transfer from nucleophiles, such as C6H5COCH2− and CH3COCH2−, to DBA2+, (3) the biradical DBA\underset.2 produced by two-electron transfer from nucleophiles such as OH−, CN−, CCl3−, and C6H5S− and (4) 10,10′-dimethyl-9,9′-bi(dihydroacridinylidene) produced from DBA\underset.2. Only the nucleophiles of (3), which produced DBA\underset.2 brought about the luminescence of lucigenin in the presence of oxygen, and DBA\underset.2 also showed luminescence in organic solvents in the presence of oxygen. From these findings it was concluded that the first process of the chemiluminescent reaction of lucigenin was the electron transfer reduction of DBA2+ by the nucleophiles to form the biradical DBA\underset.2.
A Synthesis of 3′-Deoxybutirosin B
Authors: Watanabe Isamu , Ejima Akio , Tsuchiya Tsutomu , Ikeda Daishiro , Umezawa Sumio
Published: July 2006

3′-Deoxybutirosin B (13) was prepared from 3′-deoxyparomamine (1), d-ribose and (S)-4-amino-2-hydroxybutyric acid (AHBA). The synthesis involves replacement of the 6′-hydroxyl group of 3′-deoxyparomamine with azido group, 1,6-carbamate ring formation, condensation with tri-O-(p-nitrobenzovl)-α,β-d-ribofuranosyl bromide, selective cleavage of the carbamate ring, and acylation of the free amino group at C-1 with AHBA.
Absorption Spectra of Bis(sulfito) and Bis(thiosulfato) Complexes of Cobalt(III)
Authors: Akamatsu Keiji , Hidaka Jinsai , Shimura Yoichi
Published: July 2006

It has been shown that the near ultraviolet “specific band” of a trans isomer of bis(sulfito) or bis(thiosulfato) cobalt(III) complexes is more bathochromic than the corresponding cis isomer. The cis-[Co(SO3)2(en)2]− complex was optically resolved and its circular dichroism spectrum reported.
Pseudohalogen Chemistry. V. Homolytic Addition of Thiocyanogen Chloride to Some Haloalkenes on Irradiation with UV Light
Authors: Guy Robert G , Pearson Ian
Published: July 2006

When irradiated with UV light, thiocyanogen chloride reacts with haloalkenes containing 1–4 halo substituents yielding α-chloro-β-thiocyanato compounds. Addition to unsymmetrical alkenes is regioselectively antiMarkownikov. A radical-chain mechanism, involving SH2 displacement on the sulfur atom of thiocyanogen chloride and chlorine atoms as the adding/chain-carrying species, is proposed.
Ullmann Condensation Reaction of Haloanthraquinone Derivatives with Amines in Aprotic Solvents
Authors: Arai Sadao , Yamagishi Takamichi , Ototake Satoshi , Hida Mitsuhiko
Published: July 2006

Cuprous catalysts were more effective than cupric ones in the Ullmann condensation of haloanthraquinones with amines in aprotic media. In the presence of Cu(I) catalyst, amines with a hydroxyl group (3-amino-1-propanol and 2-aminoethanol) were more reactive than the higher basic butylamine.
Magnetic Circular Dichroism of the Thulium and Erbium Ethyl Sulfate Nonahydrate Crystals
Authors: Kato Yoshifumi , Nakaya Toshikazu , Nagai Toshiyuki
Published: July 2006

The magnetic circular dichroism and absorption spectra of the thulium and erbium ethyl sulfate nonahydrate crystals have been measured at low temperatures, down to 18 K. The analyses are made for five absorption bands of Tm(C2H5SO4)3·9H2O; the bands from the ground state, 3H6, to the excited states 3F3, 3F2, 1G4,1D2, and 3P1 of Tm3+, and for four bands of Er(C2H5SO4)3·9H2O; the bands from the ground state, 4I15⁄2, to the excited states 4S3⁄2, 4F5⁄2, 4F3⁄2, and 2G9⁄2 of Er3+. With the aid of the information about energy levels already obtained, the g values of the crystal levels relevant to absorptions are derived from the Faraday parameters; these are in good agreement with those obtained by other methods.
A Semi-empirical NDDO Method for All-valence-electron Systems. I. Hydrocarbons
Authors: Kikuchi Osamu
Published: July 2006

A semi-empirical NDDO method is applied to the evaluation of the molecular geometries and excitation energies of a variety of hydrocarbons, both saturated and conjugated, and of the heats of reactions among these hydrocarbons. Two-center electron repulsion integrals are evaluated by the simple formulae derived from the corresponding theoretical formulae. The off-diagonal core matrix elements and core-core repulsion energies are estimated empirically. It is shown that the method gives good estimates of the molecular geometries and excitation energies and permissible values for the heats of reactions.
The Infrared Band Shapes of Methyl Iodide in Solutions
Authors: Ikawa Shun-ichi , Fukushi Kohji , Fujiwara Kenji , Kimura Masao
Published: July 2006

The infrared band shapes of methyl iodide in solutions were simulated by the superposition of the Lorentzian functions. The a1-type band was well repoduced by a single Lorentzian function. Its half-width was reasonably explained by the reorientational and vibrational relaxations. The e-type band was reproduced by two Lorentzian functions; one represents the central main peak of the band, while the other is much broader and appears like a background. The half-width of the former was nearly proportional to the Q-branch line spacing in the gas spectrum, while that of the latter seems to be related to the A1-E-type Coriolis coupling.
The Effect of the Deuterium Substituent on the Anomalous Phase Transition of the Crystalline Galvinoxyl Radical
Authors: Mukai Kazuo , Mishina Tadashi , Ishizu Kazuhiko , Deguchi Yasuo
Published: July 2006

Two kinds of deuterium substituents of the galvinoxyl radical have been synthesized, and the effect of the deuterium substitution on the anomalous phase transition of the crystalline galvinoxyl radical at 82 K has been studied. The results, investigated by means of ESR and magnetic susceptibility measurements, indicate that the effect was not strong enough to induce any observable change in the transition.
Photochemical Study of the Alkylammonium Molybdates. III. Preparation and Properties
Authors: Yamase Toshihiro , Ikawa Tsuneo
Published: July 2006

Six alkylammonium molybdates which we have prepared were examined for photochemical and photochromic properties in a solid and in an aqueous solution. The white crystals were reddish brown or violet when irradiated with UV light. Five compounds of the six were photochromic under aerobic conditions. The thermal return to the white color was slow, taking several hours at room temperature. The irradiation of the aqueous solution (pH 4.3–6.5) by UV light caused a blue coloration; the quantum yield increased with an increase in the molybdate concentration. A UV-induced coloration in both solid and solution was ascribable to the photoreduction of Mo(VI) to Mo(V). The blue form in the aqueous solution possesses several unique characteristics, including: (1) g=1.926 and a=52 G in its ESR spectrum; (2) the oxidation of Mo(V) to Mo(VI) upon exposure to oxygen, with an accompanying bleaching, and (3) thermochromism (blue form\leftrightarrowsgreenish yellow form) with ΔHr≈15 kcal/mol.
Hydrocracking of Tetralin on Supported Nickel–Tungsten Catalysts
Authors: Yamadaya Shoko , Oba Masaaki , Miki Yasuo
Published: July 2006

The hydrocracking of tetralin was carried out over supported nickel–tungsten (NiO 3%, WO3 20%) on silica–alumina, alumina, and silica catalysts at a hydrogen pressure of 100 atm and in the temperature range from 325 to 375 °C. The total conversion of tetralin and the product composition of hydrocracking were measured for the catalysts. The influence of pretreatment of the catalysts with H2 and H2S on the conversion and product composition was investigated for each catalyst. The hydrocracking of decalin was also carried out under the same conditions. It is found that the hydrocracking of tetralin proceeds along two reaction paths: (A) hydrogenation to decalin followed by conversion to methylperhydroindenes and C10-naphthenes, (B) isomerization to methylindans followed by cracking to butylbenzene. The selectivity of each reaction path and the catalytic properties are discussed.
Molar Excess Enthalpies of α,ω-Alkanediol Monoalkyl Ether+Heptane Systems at 298 K
Authors: Kimura Fumio , Murakami Sachio , Fujishiro Ryoichi , Toshiyasu Yoshio
Published: July 2006

Enthalpies of mixing of some α,ω-alkanediol monoalkyl ether(ADAE)+heptane systems were measured at 298 K, and limiting partial molar excess enthalpies of ADAE at infinite dilution, x→0lim  HE⁄x(1−x), were estimated. The ADAE used were CH3O(CH2)nOH (n=2, 3, 4), C2H5O(CH2)nOH (n=2, 3), C3H7O(CH2)nOH (n=2, 3), and C4H9O(CH2)2OH. The values of x→0lim  HE⁄x(1−x), obtained were compared with those of normal alcohols, and discussed in the light of the intramolecular hydrogen bond contained in ADAE. The enthalpic contribution due to the intramolecular hydrogen bond in ADAE is estimated to be about 10 kJ mol−1.
Heat Capacity of Potassium p-Chloranil Anion Radical Salt between 13 and 330 K
Authors: Kosaki Akio , Sorai Michio , Suga Hiroshi , Seki Syûzô
Published: July 2006

The heat capacity measurement for an organic free-radical salt, potassium p-chloranil, revealed a first-order phase transition at Tc=260.01 K. In spite of a first-order nature, the pre- and the post-transitional effects are remarkable. The enthalpy and the entropy of transition were determined to be ΔH=2796 J mol−1 and ΔS=11.06 JK−1 mol−1, respectively. The magnetic contribution to ΔS is only 2.23 JK−1 mol−1 when a dimeric configuration with a singlet-triplet spin equilibrium is assumed in the low temperature phase and a monomeric behavior of radicals with spin doublet is assumed above Tc. The present phase transition bears a close resemblance to a spin-Peierls transition in a linear chain system. The infrared spectrum at 120 K indicates a possible formation of dimers in the low temperature phase of this salt. A phenomenological model for the present phase transition is presented.
Acidic Properties of SiO2–MoO3 and MoO3, and Their Catalytic Activities
Authors: Maruyama Kazumasa , Hattori Hideshi , Tanabe Kozo
Published: July 2006

MoO3, SiO2, and SiO2–MoO3 of different compositions were prepared and their surface and catalytic properties examined. A large number of acid sites were generated by mixing SiO2 with MoO3, while each component oxide by itself did not exhibit any appreciable acidic properties. The oxidizing property of MoO3 was enhanced by mixing with SiO2. No new compounds were detected in the oxide mixture by X-ray diffraction. The activity for depolymerization of 2,4,6-trimethyl-1,3,5-trioxane correlated well with the surface acidity. In the isomerization of 1-butene, both MoO3 and SiO2–MoO3 were active. The active sites on MoO3 were poisoned by CO2 but not by NH3, while those on SiO2–MoO3 were poisoned by NH3 but not by CO2.
Crystal Field Levels of Neodymium and Erbium Ethylsulfate Nonahydrates
Authors: Kato Yoshifumi , Nagai Toshiyuki , Saika Apollo
Published: July 2006

The energy levels of the Nd3+ ion in Nd(C2H5SO4)3·9H2O and of the Er3+ ion in Er(C2H5SO4)3·9H2O are calculated within the 4fN configuration by the tensor operator method. The Hamiltonian containing a configuration interaction is diagonalized for the free ion levels and complete J-mixing is performed for the crystal field levels. The experimental “free-ion” energy levels of Nd3+ and Er3+ are fitted with a mean deviation of 70.8 cm−1 for 19 terms and 78.2 cm−1 for 22 terms, respectively. The crystal field parameters obtained for Nd(C2H5SO4)3·9H2O and Er(C2H5SO4)3·9H2O yield a mean deviation of 3.6 cm−1 for 43 levels and 3.6 cm−1 for 50 levels, respectively. The calculated Zeeman splitting factors (g values) in the direction along the crystal principal axis are in fair agreement with the experimental values.
Quantitative Analysis of Hydrogen in Titanium with an Ion Microanalyzer
Authors: Okajima Yoshiaki , Aizawa Yukiyoshi , Suzuki Katsumi , Sugawara Yasushi
Published: July 2006

Quantitative analysis of hydrogen in titanium was investigated with an ion microanalyzer. Argon ions as primaries were accelerated at a voltage of 10 kV. The diameter and the current of the beam were 1 mm and 2 μA, respectively. A mass spectrum was measured at 2×10−7 Torr. It was found that the intensity ratio of m⁄e=49(48TiH+) and 46(46Ti+) can be used for the determination of hydrogen in titanium. A linear relation was obtained between the intensity ratio and hydrogen concentration determined by the standard vacuum fusion method. The present method was applied to determine the hydrogen concentration in the surface layer of a sample treated by cathodic polarization. It was observed that hydrogen concentrations in the surface layer were much higher than those in the bulk of the sample.
Phase Equilibria in Sm2O3–V2O3–V2O5 System at 1200 °C
Authors: Kitayama Kenzo , Katsura Takashi
Published: July 2006

The phase equilibria in the Sm2O3–V2O3–V2O5 system was established at 1200 °C. In this system, Sm2O3, Sm10V2O20, SmVO3, SmVO4, V2O3, V3O5, V4O7, V5O9, V6O11 and VO2 were stable and Sm10V2O20, SmVO4, V2O3, and VO2 had the non-stoichiometry. On the basis of the phase equilibria, the Gibbs free energy for the reactions, SmVO3+1⁄2O2=SmVO4 and 4 Sm2O3+2 SmVO3+O2=Sm10V2O20, were determined to be −30.4±0.1 and −76.8±0.1 kcal, respectively. Also, standard Gibbs free energies of oxidation of various vanadium oxides were calculated.
Palladium(II) Complexes of 2,2,6,6-Tetramethylpiperidine N-Oxyl Radical
Authors: Okunaka Masaaki , Matsubayashi Gen-etsu , Tanaka Toshio
Published: July 2006

2,2,6,6-Tetramethylpiperidine N-oxyl radical (CH3)4C5H6NO· (TMPNO·) reacts with palladium dichloride to give complexes of both anionic and cationic TMPNO; [PdCl(TMPNO)]2 (I) and [TMPNO+]2[Pd2Cl6]2− (II). I further reacts with dimethylsulfonium phenacylide or triphenylphosphine (L) to afford a mononuclear complex of the PdCl(TMPNO)(L) type. II undergoes a facile reaction with acetone to yield bis(N-acetonyl-N-hydroxy-2,2,6,6-tetramethylpiperidinium)hexachlorodipalladate, [(CH3)4C5H6\overset+N(OH)CH2COCH3]2[Pd2Cl6]2−. Configurations of these complexes are described.