bluuebunny/crossref_metadata_2025 huggingface dataset:
The Electronic Absorption Spectra of Fatty Acid Mono-, Bi-, and Multilayers with Bivalent Metal Ions
Authors: Nagahira Yukio , Matsuki Kazunori , Fukutome Hideo
Published: July 2006

The electronic absorption spectra of fatty acid multilayers with bivalent metal ions were studied in the vacuum ultraviolet (VUV) to ultraviolet (UV) energy region below 8 eV; they are due to transitions in the carboxylic acid and metal carboxylate moieties. Infrared (IR) absorptions due to the C–O stretching vibration in the carboxylate moiety are also studied. Stearic acid multilayers without metal ions are shown to form hydrogen-bonded dimers. The spectra of multilayers with metal ions show a marked dependence on the subphase pH which is different for different kinds of adsorbed metal ions. Their VUV spectra are conspicuously dependent on the kind of metal ions adsorbed. All the multilayers with alkaline earth metals, metals of the 2B group, transition metals, Cu, and Pb have at least two bands in the VUV region, 7.3–6.3 eV. The polarization spectra of the Ba stearate multilayer suggest that the two transitions may be the intramolecular π-π* and n-π* transitions in the carboxylate anion moiety. The multilayers with Cu and Pb have another band in the UV region. The spectra of the UV bands of the Pb and Cu stearate mono-, bi-, and multilayers were studied. In the Pb stearate layers, the positions of the UV bands in the bi- and multilayers are the same, but those in the monolayers are at considerably shorter wavelengths. The positions of the UV band in the Cu stearate mono-, bi-, and multilayers are successively red shifted. The polarization spectra of the UV bands of the mono- and bilayers showed that they are charge-transfer bands between the Pb or Cu ion and the coordinated carboxylate moiety.
The Synthesis of Potassium Pentacyanohydroxochromate(III)
Authors: Sakabe Yuzuru , Matsumoto Yoshio
Published: July 2006

The crystals of K3[Cr(CN)5(OH)]·H2O have been obtained by making [CrCl(NH3)5]Cl2 react with KCN, followed by purification on a Sephadex gel column.
Ammonolysis of N-Acylpyroglutamic Acid. Permanganateoxidation of Peptides. II.
Authors: Torigoe Keisuke , Motoki Yoshiaki , Muramatsu Ichiro
Published: July 2006

The reaction of N-acylpyroglutamic acid with ammonia proceeds in two pathways. The one results in N-acylglutamine as a product, and the other in pyroglutamic acid and an amide formed from the N-acyl group. The ratio of the yields of the two reactions changes with the N-acyl group, being correlated with the acidity of the carboxylic acid from which the N-acyl group is derived, and also with the steric hindrance of the group.
A Simple Method for the Esterification of Carboxylic Acids Using Chlorosilanes
Authors: Nakao Ren , Oka Kunio , Fukumoto Tsugio
Published: July 2006

Various carboxylic esters, including some with bulky substituents, are prepared in good yields from carboxylic acids and alcohols under mild conditions by the use of trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, or tetrachlorosilane.
Carbon-13 Chemical Shifts of Polychlorobicyclo[2.2.1]heptene Derivatives
Authors: Sera Akira , Takagi Kazuhiro , Nakamura Michiko , Seguchi Kazuyoshi
Published: July 2006

The 13C chemical shifts of 5-substituted polychlorobicyclo[2.2.1]heptene derivatives were determined. The chlorine, 5-endo and 5-exo substituent effects on the chemical shifts were discussed. The differences in the C3and C7 chemical shifts are shown to be helpful for the identification of the endo and exo isomers. A possible operation of the interaction of pi electrons with a carbon-chlorine dipole is also discussed.
Studies on Heterocyclic Analogs of Azulene. VIII. Reaction of 2-Alkoxycyclohepta[6]pyrroles with Dimethyl Acetylenedicarboxylate
Authors: Abe Noritaka , Nishiwaki Tarozaemon
Published: July 2006

2-Alkoxycyclohepta[b] pyrroles reacted with dimethyl acetylenedicarboxylate to give tetramethyl 2-alkoxy-3H-2a-azacyclopenta[ef]heptalene-3,4,5,6-tetracarboxylates in benzene and dialkyl 2-(2-alkoxycyclohepta[b]pyrrol-1-yl)fumarate in alcoholic solvents.
Ketone Synthesis from Acid Chloride by Means of Organometallic Reagent Derived from R3Al–Cu(acac)2-PPh3 System
Authors: Takai Kazuhiko , Oshima Koichiro , Nozaki Hitosi
Published: July 2006

Reaction of acid chlorides or thiocarboxylic S-esters with the title reagent in tetrahydrofuran provides ketones in good to excellent yields. The coupling reactions with ally lie halides to form alkene derivatives are also disclosed.
Kinetic Studies on the Strictly Catalytic Acetylation of Mesitylene with Acetic Anhydride by HCl and Metal Chlorides in Acetic Acid
Authors: Yamanaka Tohr , Imai Takashi
Published: July 2006

On the acetylation of mesitylene (1, 0.5–1 mol dm−3) with acetic anhydride (Ac2O, 0.5–1.5 mol dm−3) at 30–90 °C in acetic acid as solvent, SbCl5, FeCl3, SnCl4, or ZnCl2 (each of 0.02–0.2 mol dm−3) under the co-catalytic effect of HCl (0–0.75 mol dm−3) showed a continuous catalytic activity. The product was exclusively 2′,4′,6′-trimethylacetophenone for conversions of 1 in the range of 0–90%. The reaction was first order with respect to 1 and Ac2O. The rate constants were proportional to 1–1.4th power of the concentration of the metal chloride. The apparent activation energy was 18.8 kcal mol−1 for all the catalysts. The catalytically active species are thought to be the conjugate acids from the metal chloride and HCl. Relative catalytic activities of the metal chlorides varied in parallel with their relative Lewis acid-strengths.
ESR and ENDOR Studies of Azulenophane Anion Radicals
Authors: Iwaizumi Masamoto , Fukazawa Yoshimasa , Kato Nobuo , Itô Shô
Published: July 2006

The anion radicals of syn- and anti-[2.2](2,6)azulenophane, (1) and (2), [2.2](1,3)azulenophane, (3), and [2](1,3)-azuleno[2]paracyclophane, (4), all produced by alkali metal reduction in various solvents, have been investigated by ESR and ENDOR spectroscopy. They exist in the ion pair with cations in the solutions, except for 4\ewdot which exists in 1,2-dimethoxyethane with Na+. Their ion pairing tendency is appreciably higher than that of the naphthalenophane anion radicals. The unpaired electron in these ion pairs localizes mostly on an azulene ring (in 1\ewdot, 2\ewdot, and 3\ewdot, close to a cation). The polarization effects due to the pairing with the cations are much larger than those in the naphthalenophane anion radicals, and increase in the order 1\ewdot≤2\ewdot≤3\ewdot, indicating that the smaller the inter-layer orbital overlap, the larger the polarizability. The unpaired electron of 4\ewdot localizes mostly on the azulene ring even in the free anion.
Theoretical and Experimental Studies of the Membrane Permeabilities to Ions in Liquid Membrane
Authors: Nomura Kazuo , Matsubara Akira , Kimizuka Hideo
Published: July 2006

A theory for the ion transport across liquid ion-exchange membrane was presented on the basis of nonequilibrium thermodynamics with the assumptions that the carrier ions and complexes were present only in the membrane phase, and that there was no volume flow and all chemical reactions were at equilibrium. The equations for “total” fluxes of membrane-permeable ions at steady state were derived from a set of the equations for “individual” fluxes of all mobile species present in the liquid membrane where the complexes were assumed to be partially dissociated. The “total” phenomenological coefficients were able to be expressed in terms of the “individual” coefficients. The diffusional and electroconductional membrane permeabilities to a selective ion in the liquid membrane–single electrolyte system were found to be in the same form as those in the fixed-site membrane–single electrolyte system, if the mean diffusion coefficient and mean mobility of the free species and its complex were used. The rate constants in the permeation process were also related to the diffusional membrane permeability. The experimental examination was made on a liquid cation-exchange membrane–aqueous single electrolyte system at 25 °C. The solution of calcium hexadecyl sulfate in 1-octanol and calcium chloride were used as the liquid membrane and the electrolyte, respectively. All the measured quantities were consistently interpreted by the presented theory.
Reduction-Reoxidation Behavior of Silver(I) Ions in X-Type Zeolites
Authors: Iwamoto Masakazu , Hashimoto Tsuneyasu , Hamano Toshikazu , Kagawa Shuichi
Published: July 2006

The reduction of Ag+ ions in X zeolites by hydrogen, the reoxidation of Ag atoms by oxygen, and the formation of silver particles were studied kinetically. The reduction is suggested to be a catalyzed reaction requiring an activation of hydrogen at some specific sites on the basis of the influence of exchange levels and hydrogen pressures on the reduction rates. At elevated temperatures the reduction of Ag+ ions proceeded quantitatively and resulted in formations of Ag particles with a diameter between 10 and 25 nm and of highly dispersed Ag clusters. The clusters were easy to be reoxidized by oxygen at 473 K or below, while the particles were difficult to revert into the zeolite matrix. The diameter of the Ag particles was dependent on the reduction temperature and ion-exchange level and independent on the reduction time. It is discussed that this is due to the slow nucleation and the fast nuclear growth of Ag particles.
Intermolecular Potential, Vibrational Spectra, and Structures of Amino Acid Crystals. I. Distortion of Molecules and Equilibrium Crystal Structure
Authors: Machida Katsunosuke , Kuroda Yoshihiro
Published: July 2006

A general method of the crystal packing optimization is developed for the molecular crystals consisting of non-rigid molecules. The intramolecular potential is described as a general harmonic force field in terms of a suitable set of internal symmetry coordinates, and the intermolecular potential as a sum of the pairwise atom-atom interaction terms. The adjustable structure parameters are those among the six cell constants, a, b, c, α, β, and γ, and the translations and the rotations of the molecules which maintain the crystal symmetry. The intermolecular force is separated into two parts, one of which determines the location of the center of mass and the orientation of the principal axes of each molecule and the other leads to a certain molecular distortion. The calculated distortion may be used, in addition to the difference between the calculated and the observed crystal structures, as a check point of the reliability of the model potential. The importance of this separation in the rigid molecule approximation is pointed out.
Sublimation Behavior of Tris(2,2,6,6-tetramethyl-3,5-heptanedionato)lanthanoid(III)
Authors: Amano Ryohei , Sato Akiko , Suzuki Shin
Published: July 2006

Two fundamental experiments (to determine vapor pressures and vacuum sublimation-recrystallizing temperature zones) were undertaken on a series of remarkably volatile and thermally stable lanthanoid(III) chelates of 2,2,6,6-tetramethyl-3,5-heptanedione (Ln(thd)3) in order to obtain information about their sublimation behavior. Vapor pressures of these chelates were measured from 100 to 150 °C by means of a modified Knudsen effusion technique. Vacuum sublimation-recrystallizing temperatures were determined by using a sublimation apparatus with a continuous temperature gradient along its sublimation tube. The obtained enthalpies of sublimation were classified into three groups (La to Gd, Tb and Dy, and Ho to Lu), and the vacuum sublimation-recrystallizing temperature zones were divided into two sets (La to Tb, and Dy to Lu). The Tb and Dy chelates were also found to change thermally from a dimeric form to a monomeric form at a definite temperature. These results are explained in terms of the two different crystallizing forms of Ln(thd)3 chelates. Furthermore, the regularity in their sublimation behavior is discussed as a function of the atomic numbers of the lanthanoid metals, using thermochemical considerations.
The Temperature Dependence of the Trapped and Averaged-valence State in Mono-oxidized Dialkylbiferrocenes
Authors: Iijima Sei’ichiro , Saida Ritsuko , Motoyama Izumi , Sano Hirotoshi
Published: July 2006

An interesting temperature dependence of the valence state was observed in the Mössbauer spectra of the mixed-valence salts of 1′,1'″-dialkylbiferrocenes, measured at various temperatures from 4.2 K to 300 K. A mechanistic consideration of the temperature dependence has been carried out assuming a conformational change of the monocation salts induced both by the variation in the temperature and by the kind of counter anion.
Oxidation-Reduction Properties of Mixed Oxides in the Cerium–Uranium–Oxygen System
Authors: Tagawa Hiroaki , Fujino Takeo , Watanabe Kenju , Nakagawa Yumiko , Saita K\={o}ji
Published: July 2006

The formation and the oxidation-reduction properties of mixed oxides in the Ce–U–O ternary system were examined by means of thermogravimetry and the X-ray diffraction technique. The mixed oxides were prepared by the reactions of CeO2 with U3O8 in air and in hydrogen. The composition of the products heated in air, followed by slow cooling to room temperature, was approximately expressed by this equation: yCeO2+(1–y)UO2.67. By X-ray diffraction, it was shown that the oxides formed at 1100 °C in air were mixtures of Ce0.6U0.4O2.3 and α-U3O8 in the y<0.6 range, while they were in single phases of solid solutions for y≥0.6. When the mixed oxides, MO2+X, where M indicates yCe+(1–y)U, were re-heated in air, weight loss due to oxygen liberation was observed above 500 °C, and it was enhanced with a rise in the temperature. The hydrogen reduction of the oxides proceeded in two steps; the first step was the reduction of MO2+X to MO2 below 600 °C, and the second one was the reduction of MO2 to MO2−X above 600 °C. The composition of the oxides obtained can be given by this equation: yCeO1.81+(1–y)UO2.00. Two separate linear relationships for the lattice parameter of the fluorite-type structure as a function of the cerium content were obtained; one is applicable to the solid solutions with y≤0.6, where the lattice parameter is nearly that of UO2, and the other to the solid solutions with y≥0.4. The latter obeys Vegard’s law between UO2 and CeO2. The oxides with y=0.4–0.6 were in the two-phase region of the solid solutions.
The Solution Chemistry of Organotin Compounds. I. A 1H NMR Study of the Complex Formation between Methyltin Trichloride and 4-Substituted Pyridines
Authors: Fujiwara Hideaki , Sakai Fumihiko , Takeyama Miyoko , Sasaki Yoshio
Published: July 2006

The formation of donor-acceptor complexes between MeSnCl3 and 4-substituted pyridines has been investigated by analyzing the concentration dependence of NMR parameters. The formation of 1(MeSnCl3):2(pyridine) and 1:1 complexes has been proved, and the equilibrium constants(K1 and K2) and complex formation shifts (ΔAB and ΔAB2) are determined for the successive formation of these complexes, logK1 and logK2 are in a good linear correlation with each other, and they have a tendency parallel with that of pKa of the pyridine derivative, suggesting a predominant contribution of σ-bonding in the donor-acceptor bond. Both ΔAB and ΔAB2 indicate a high-field shift on the formation of the complex, which is consistent with the expected electron transfer in the donor-acceptor bond. However, ΔAB varies inversely to the basicity of the pyridines; the anisotropy effect of the pyridine ring is suggested as the reason for this. The results are also discussed in relation to Hammett’s substituent constant.
The Thermal Decomposition of Sodium Nitrate and the Effects of Several Oxides on the Decomposition
Authors: Hoshino Yoshio , Utsunomiya Taizo , Abe Osami
Published: July 2006

The thermal decomposition of sodium nitrate and the effects of several oxides, such as silica, titania, zirconia, alumina, and magnesia, on the decomposition were studied up to 900 °C by means of the thermal analysis, gas analysis, and chemical analysis of the reaction products. The reaction of sodium nitrate and silica was especially investigated in some detail over a wide composition range. The thermal decomposition of sodium nitrate started at about 450 °C. The gases formed were O2, NO, and N2, the formation of N2 being detected above 680 °C The thermal decomposition of sodium nitrate was supposed to consist of the following three successive or concurrent reaction processes, according to the degree of the reaction: (I) the decomposition of sodium nitrate to nitrite and oxygen, (II) the first-order liquid-phase reaction, with some kind of quantitative relationship between nitrate and nitrite, and (III) the formation reaction of sodium oxide, expressed by the Avrami-Erofe’ef equation. The (II) and (III) reaction processes can be reasonably interpreted if the existence of the peroxide ion is assumed. Acidic oxides, such as silica and titania, were supposed to lower the activation energy of the (III) reaction process by forming stable salts with sodium nitrate and/or its intermediate reaction products. The effects of these oxides on the thermal decomposition of sodium nitrate could be interpreted by the relative scale of the acidity of oxides.
The Conformational Analysis of a Series of 4,8-Dimethyl-6-phenyl-5,6,7,8-tetrahydro-4H-1,3,2,6-dioxathiazocine 2-Oxides Using NMR
Authors: Nishiyama Tomihiro , Nakai Yasushi , Shishibori Hideaki , Yamada Fukiko
Published: July 2006

The title compounds were prepared, and their 1H- and 13C-NMR spectra were examined. On the basis of the data for the benzene–solute collision complexes and the magnitudes of the γ shifts, five isomeric conformations of the compounds were discussed.
The Methylation of Nucleic Acids. The Analysis of Methylated Ribonucleosides by Means of High-performance Liquid ODS–Silica Gel and Cation-exchange Chromatography
Authors: Tanabe Toshizumi , Yamauchi Kiyoshi , Kinoshita Masayoshi
Published: July 2006

The quantitative determination of adenosine, guanosine, inosine, cytidine, uridine, and their methylated derivatives was studied by means of a high-performance liquid chromatographic method using ODS–silica gel cation-exchange, and anion-exchange resins as column packings. The method was apphed to the analysis of yeast-RNA, which was methylated by trimethyl phosphate at pH 7 and 9.
Asymmetric Reduction of Aromatic Ketones with Reagents Prepared from NaBH4 and ZnCl2 in the Presence of 1,2 : 5,6-Di-O-isopropylidene-α-d-glucofuranose
Authors: Hirao Akira , Ohwa Masaki , Itsuno Shinichi , Mochizuki Hidenori , Nakahara Seiichi , Yamazaki Noboru
Published: July 2006

Asymmetric reduction of prochiral aromatic ketones using a freshly prepared complex derived from NaBH4, 1/3 equiv of ZnCl2, and 1,2 : 5,6-di-O-isopropylidene-α-d-glucofuranose (1) gives an excess of the corresponding (S)-alcohols in substantial optical yields (28–68%). The effects of the NaBH4/ZnCl2/1 ratio, temperature, solvent, structure of various monosaccharide derivatives, and the metal cation of the reagent on the optical yields were examined.
The Extraction of the Tungsten(VI)–Pyrocatechol Violet Complex with Tridodecylethylammonium Bromide
Authors: Shijo Yoshio , Shimizu Tokuo , Sakai Kaoru
Published: July 2006

The extraction equilibria and the fundamental conditions were studied for extracting the tungsten(VI)–Pyrocatechol Violet complex anion in a form of an ionic associate with tridodecylethylammonium salt in carbon tetrachloride. The ternary complex has an absorption maxima at 575 nm in the organic phase. The optimum pH range for the extraction is 4.8–5.6. The distribution ratio and the molar absorptivity are 3.3×102 and 4.7×104 dm3 mol−1 cm−1 respectively. The composition of the ternary complex is estimated to be WO2(PV)2(R3R′N)2.The extraction constant would be:

K ex=\frac[WO2(PV)2(R3R′N)2]o[WO2(PV)22−][R3R′N+]2.

It is given by logKex=13.56. Many foreign cations can be masked with CyDTA.
The Reaction of 2-Ethoxy-1,3-dithiolane with Carbonyl Compounds
Authors: Jo Shigeo , Tanimoto Shigeo , Oida Tatsuo , Okano Masaya
Published: July 2006

The reaction of 2-ethoxy-1,3-dithiolane with carbonyl compounds such as aldehydes and ketones was investigated. The reaction proceeded smoothly in the presence of the HgCl2-catalyst to afford 2-substituted and 2,2-disubstituted 1,3-dithiolanes. The reaction also offers an interesting alternative to the previously reported methods of synthesizing 1,3-dithiolanes which involve the acid-catalyzed reaction of carbonyl compounds with 1,2-ethanedithiol.
Intramolecular Cyclization of Nerol and the Related Attack of (Z)-Allylic Alcohol Moiety on the Terminal Olefin Linkage as Induced by TiCl4–PhNHMe Complex. Synthesis of Nezukone
Authors: Itoh Akira , Saito Tadashi , Oshima Koichiro , Nozaki Hitosi
Published: July 2006

Nerol was cyclized to terpinyl chloride or bromide in the presence of TiX4–PhNHMe (1 : 1) complex (I, X= Cl, Br) in dichloromethane at −23 °C, geraniol being converted into geranyl halide by simple halogenation. Terminally modified derivatives YCH2C(Me)=CHCH2CH2CMe=CHCH2OH (Y=SiMe3, SnBu3) of (2Z,6E) configuration were cyclized by treatment with I to afford limonene in high yields and 100% selectivity. Cyclization of (2Z) isomers of CH2=CR–CH2CH2CMe=CHCH2OH (R=H, Me, Cl) produced seven-membered carbocyclic products in fair yields. The novel procedure has been utilized in the synthesis of nezukone from (2E)-3-isopropyl-2,6-heptadien-1-ol involving five steps.
Tellurium-catalyzed Carbonylation of Amines with Carbon Monoxide
Authors: Kambe Nobuaki , Kondo Kiyoshi , Ishii Hideo , Sonoda Noboru
Published: July 2006

Carbonylation of amines with carbon monoxide was catalyzed by tellurium to produce corresponding urea derivatives, formamides, and molecular hydrogen. The urea formation proceeds according to the equation; 2RNH2+CO→(RNH)2CO+H2. The successful achievement of the catalytic formation of urea derivatives would be due to the thermal instability of hydrogen telluride which decomposes to generate elemental tellurium and hydrogen. The formation of formamides and hydrogen was found to be suppressed by the addition of nitrobenzene which did not affect the urea formation. Effects of the reaction time, temperature, pressure of carbon monoxide, and additives on this carbonylation reaction are discussed.
Reactivities of Stable Rotamers. VI. Manifestation of Differential Reactivities of the Methyls in a t-Butyl Group in Radical Halogenations
Authors: Seki Shigetaka , Morinaga Tsutou , Kikuchi Hiromi , Mitsuhashi Tsutomu , Yamamoto Gaku , Oki Michinori
Published: July 2006

The methyls in a t-butyl group are shown to exhibit different reactivities in radical halogenations, if rotation about a (CH3)3C–CXY2 bond is frozen. Barriers to rotation of halogenated 9-t-butyl-1,2,3,4-tetrachlorotriptycenes are obtained as ΔH\eweq  ca. 32 kcal/mol. The cause of the selectivity in chlorination with sulfuryl chloride was discussed by obtaining reactivity data with a variety of compounds and halogenating reagents. It is concluded that the neighboring group participation of the peri-halo substituent is responsible for the observed selectivity.
Kinetic and Equilibrium Studies on Substitution Reactions of the Chlorobis(β-diketonato)manganese(III) Complexes with Other β-Diketones
Authors: Ito Yoshiaki , Kawaguchi Shinichi
Published: July 2006

The MnCl(β-dik)2 complexes, where β-dik stands for an anion of acetylacetone, benzoylacetone, and dibenzoylmethane, were confirmed to have the five-coordinate structure in dichloromethane and their adduct formation constants with various donor solvents were measured. Equilibria and kinetics of substitution reactions of MnCl(β-dik)2 with other β-diketones were determined by the spectrophotometric method and the mechanism for these reaction is proposed.
Singlet-excitation Migration in Pure Liquid Methyl- and Ethylnaphthalenes
Authors: Ohno Takeshi , Kato Shunji
Published: July 2006

The fluorescence quenching of solvent molecules and solute molecules was studied in the alkylnaphthalene solvents. The singlet-excited states of the solvent molecules were quenched by 1,4-bis(trichloromethyl)benzene with the rate parameter of 2.8×1010 mol−1 dm3 s−1 at 45 °C. This rate parameter is twelve times as great as that of the solute, dibenz[a,c]anthracene, in the solvent, 1-methylnaphthalene. The diffusion constant of the excitation migration of the solvent molecule is calculated to be larger (0.35×10−4 cm2 s−1 at 45 °C) than that (0.03×10−4 cm2 s−1) of the solute. The temperature coefficient (22 kJ/mol) of the excitation migration is too small to explain the migration mechanism on the hypothesis of the “successive association-dissociation reaction of excimer” proposed by Birks. The presence of a short-range exciton in the liquid is likely.
An Ab Initio Calculation of the Electronic Structure of the [Co(CN6)]3− Ion
Authors: Sano Mitsuru , Hatano Yasuyo , Kashiwagi Hiroshi , Yamatera Hideo
Published: July 2006

Ab  initio LCAO MO SCF calculations were carried out on [Co(CN)6]3−. The character of the wave-functions was discussed in terms of the orbital-mixing rule. The radial distribution of electron density obtained from molecular orbital (MO) calculation was compared with that obtained from X-ray experiments. On the ionization from a metal d-orbital, a significant electronic relaxation was shown to occur, which makes Koopmans’ theorem invalid. The calculated excitation energies without a configuration interaction showed a qualitative correspondence with the absorption spectrum.
The CD Spectra of Carbonato Complexes of the [Co(CO3)(O,O)(N)2]− and [Co(CO3)(N)4]+ Types and Related Diaqua Complexes
Authors: Tsuji Kenshi , Fujinami Shuhei , Shibata Muraji
Published: July 2006

Five carbonato complexes, [Co(CO3)(ox)(tn)]−, cis-[Co(CO3)(ox)(py)2]−, cis·cis-[Co(CO3)(NH3)2(py)2]+, cis-[Co(CO3)(en)(py)2]+, cis-[Co(CO3)(NH3)2(bpy)]+, and two related complexes, cis-[Co(ox)(NH3)2(en)]+ and cis-[Co(mal)(NH3)2(en)]+, have been prepared and resolved. The solution CD spectra of these resolved complexes and those of diaqua complexes derived from the carbonato complexes have been measured. The CD spectral comparison in the first absorption band (T1g-band) region has suggested a relation in the sign of the Cotton peak between each of the carbonato complexes and the corresponding diaqua complex. Based on this relation, the assignments of the absolute configurations for the present complexes have been established.
Spectrophotometric Determination of Iron(III) with N,N′-Bis(2-hydroxybenzyl)ethylenediamine-N,N′-diacetic Acid
Authors: Katsuyama Tetsuo , Kumai Toshihiko
Published: July 2006

N,N′-Bis(2-hydroxybenzyl)ethylenediamine-N,N′-diacetic acid (hbed) reacts with iron(III) to form a red complex having an absorption maximum at 485 nm. The iron(III) complex is so stable that the maximum absorbance of the solution is constant over the pH range from 2.5 to 13.2 and a large excess of reagent is not necessary. Beer’s law is obeyed up to 1.6×10−4 mol dm−3 (9 μg cm−3) of iron(III). The molar absorption coefficient is 3.95×103 1 cm−1 mol−1, and the relative standard deviation for determination of 3.5 μg cm−3 of iron was 0.29%. The molar ratio of iron(III) to hbed was found to be 1 : 1. The effect of 32 diverse ions was examined; only colored aqua metal ions interfere. The present method was applied to the determination of iron in aluminium alloys.
Wet Oxidation of Water-soluble Polymers
Authors: Imamura Sei-ichiro , Tonomura Yoshiaki , Kawabata Nariyoshi , Kitao Takane
Published: July 2006

Wet oxidation of various water-soluble polymers was carried out with particular attention given to the reactivity of polyethylene glycol. Polymers with high molecular weight were more reactive than their low molecular weight analogues or monomer models. It is suggested that the high reactivity of the polymers can be attributed to the ease of an intramolecular hydrogen abstraction in the propagation step of oxidation. Bio-degradability of the polymers was highly improved by wet oxidation. Wet oxidation is especially effective for the treatment of waste water containing water-soluble polymers.
Peroxomonophosphoric Acid Oxidation. V. A Kinetic and Mechanistic Study of Oxidation of Aminobenzoic Acids in Acid Medium. Double Bell Shaped pH Rate Profile
Authors: Panigrahi Ganesh Prasad , Panda Abhina Kumar
Published: July 2006

Anthranilic acid and p-aminobenzoic acid were oxidized with peroxomonophosphoric acid in aqueous acid medium to the corresponding azoxy derivatives. Suitable rate laws for the double bell shaped pH rate profile were derived and rationalized on the basis of protonation of the amino group and ionization of the carboxyl group. The mechanism of oxidation involves the nucleophilic attack of nitrogen on the electrophilic peroxo oxygen. The reactivity of different peroxomonophosphoric acid species has been estimated.
Monophotonic Ionization Mechanism of N,N,N′,N′-Tetramethyl-1,6-pyrenediamine in Acetonitrile Solution
Authors: Nogami Takashi , Mizuhara Toshio , Kobayashi Naoki , Aoki Masaaki , Akashi Takao , Shirota Yasuhiko , Mikawa Hiroshi , Sumitani Minoru
Published: July 2006

Monophotonic ionization of N,N,N′,N′-tetramethyl-1,6-pyrenediamine (TMPDA) in acetonitrile was studied by means of ns laser photolysis and transient photocurrent measurement. The time dependences of the absorption of TMPDA cation radical and of the photocurrent were different. Photoionization thus occurs through an ionpair state.
The Separation of Solutes with Different Diffusion-coefficients by Two-layer Convection
Authors: Kamakura Katsuyoshi
Published: July 2006

When a two-layer system which consists of water (upper layer) and an aqueous solution (lower layer) is heated from one side and cooled from the opposite side, a convection starts in each layer. The empirical formula for mass transfer between the convections was studied for a system of water containing a mixture of solutes; the flux of a solute in the mixture was found to be proportional to the square root of the diffusion coefficient of the solute. Therefore, solutes with different diffusion-coefficients can be separated by two-layer convection.
A New Route to Vitispiranes
Authors: Kato Tetsuya , Kondo Hisao
Published: July 2006

Diastereoisomeric vitispiranes have been synthesized from 2,6,6-trimethyl-1-(3-oxo-1-butenyl)-1,3-cyclohexadiene by five-step reactions including photooxy-genation.
1,3-Dioxolane Bearing Perfume and Herbicide Aldehyde Residues
Authors: Kamogawa Hiroyoshi , Haramoto Yuichiro , Nakazawa Terumi , Sugiura Harumitsu , Nanasawa Masato
Published: July 2006

4-Methacryloyloxymethyl-1,3-dioxolanes substituted at the 2 position with perfume and herbicide aldehyde residues were synthesized either by acetalization or by transacetalization involving 2,3-dihydroxypropyl methacrylate. The effect of the 2-substituent of the dioxolane ring on the rate of hydrolysis was remarkable.
Substituent Effect on the N–H Stretching Absorptions of 2-(Substituted anilino)pyridines
Authors: Hirota Minoru , Kobayashi Kunio
Published: July 2006

The N–H stretching frequencies of the title compounds were determined precisely. These amines have two absorption bands in the N–H stretching region owing to the existence of the rotational isomers. Their frequencies were plotted against the Hammett σ-constants of the substituents, giving a negative ρ-value. The results gave support to the planar (sp2) conformation of the exo-cyclic nitrogen atom.
A Selective Monodehydration of C4−14-α,ω-Alkanediols with Stearic and/or Palmitic Acids
Authors: Yamanaka Tohr , Imai Takashi
Published: July 2006

The formation of monoesters of the C4−14-α,ω-alkanediol(1) with stearic and/or palmitic acids and the consecutive pyrolysis of the monoesters to an ω-alken-1-ol(2) were effected at 320–350 °C under 260–760 mmHg** in a backmix flow reactor of a constant volume equipped with a fractionating column, through which the unchanged 1 was partially recycled. The selectivity in the preparations of 2(C6, C10, and C14) was greater than 79%.
Regiospecific Synthesis of 3-Alkylfurans and 3-Alkylthiophenes via Organoboranes
Authors: Akimoto Itaru , Sano Masahiro , Suzuki Akira
Published: July 2006

The reaction of bromine or iodine with ate-complexes obtained from trialkylboranes and 3-lithiofuran or 3-lithiothiophene gives the corresponding 3-alkylfurans or 3-alkylthiophenes in good yields, respectively.
The Equilibrium and the Vibrational Spectra of the t-Butylamine–Chloroform System
Authors: Kanesaka Isao , Izumi Mitsue , Mitsuishi Misaki , Kawai Kiyoyasu
Published: July 2006

The thermodynamic constants, ΔH° and ΔS°, of the t-butylamine (TBA)–chloroform-d system in carbon tetrachloride are obtained from the analysis of the Raman intensities observed in the C–D stretching region of chloroform-d, while the ΔH° on the associated species of TBA·CDCl3 and (TBA)2·CDCl3 are evaluated to be −14.2 and −22.6 kJ/mol respectively. The IR or Raman spectrum of a solid sample, adjusted by the rapid cooling of a gaseous or liquid one respectively, with the TBA: chloroform ratio of ≈1 is compared with that of TBA in the gaseous, liquid, or solid state; it is confirmed, on the basis of the assignments of the observed frequencies, that the solid sample consists almost entirely of the associated species of TBA·CHCl3. Only one associated species of (TBA)2·CHCl3 is also obtained by the crystallization of the gaseous sample with the molar ratio of 2.0. The NH2 group vibrations in TBA·CHCl3 or (TBA)2·CHCl3 are related intimately in their frequencies and band shapes to those in gaseous or solid TBA respectively.
The Thermal and Hydrothermal Behavior of Silica-adsorbed Magnesium Hydroxide
Authors: Muraishi Haruto
Published: July 2006

Silica-adsorbed Mg(OH)2 was treated thermally and hydrothermally. The resulting change in the adsorption layer was followed, and the effects of the adsorbed silica on the change in the bulk (Mg(OH)2, MgO) were examined. (1) Thermal treatment: The dehydration temperature of Mg(OH)2 increased with an increase in the amount of silica adsorbed, and it was higher by 25 °C for Mg(OH)2 adsorbing silica above 0.4 mmol/g than for pure Mg(OH)2. The amorphous silicate of the adsorption layer on the Mg(OH)2 surface was transformed into forsterite (Mg2SiO4) and chain or sheet-like silicate over the temperature range of 870–1100 °C, and the presence of the silica inhibited the sintering and crystallite growth of the MgO grains. At 1400 °C, these products were all transformed into forsterite, and the presence of the silica had little effect on the crystallite growth. (2) Hydrothermal treatment: Below 360 °C, the amorphous silicate on the surface crystallized as serpentine (Mg3Si2O5(OH)4), and the crystallite growth of Mg(OH)2 was inhibited. Above 420 °C, on the other hand, the silicate was transformed into forsterite through serpentine-like silicate, and the crystallite growth of Mg(OH)2 was promoted. The change in the crystallite size of the bulk by the treatment was interpreted mainly in terms of the behavior of the silicate on the surface.
Transition-metal Complexes of Pyrrole Pigments. XVII. Preparation and Spectroscopic Properties of Corrole Complexes
Authors: Murakami Yukito , Matsuda Yoshihisa , Sakata Kazunori , Yamada Sunao , Tanaka Yasuhiro , Aoyama Yasuhiro
Published: July 2006

Nickel(II), copper(II), and cobalt(III) complexes were prepared with corroles; 2,3,7,8,12,13,17,18-octaethylcorrole (OEC), 2,3,17,18-tetramethyl-7,8,12,13-tetraethylcorrole (MEC), and 8,12-bis[2-(ethoxycarbonyl)ethyl]2,3,7,13,17,18-hexamethylcorrole (PMC). For the coordination with nickel and copper ions, the corroles acted as dianionic ligands to yield electrically neutral complexes. These complexes exhibited metalloporphyrin-like electronic spectra, while they showed spectra which bear a much closer resemblance to those for metalloporphyrins as the anionic complexes were formed upon addition of alkali. The corroles coordinate to tervalent cobalt as trianionic ligands to form neutral complexes, which were reduced to the corresponding cobalt(II) complexes with sodium hydroborate. These reduced species gave a unique set of g-values (g1>>g2>g3) for the complexes of macrocyclic ligands with conjugated double bond system. The plausible coordination geometry as well as the structural properties of the corrole ligands has been discussed.
Elementary Patterns in Protein–Nucleic Acid Interactions. II. Crystal Structure of 3-(Adenin-9-yl)propionamide
Authors: Takimoto Midori , Takenaka Akio , Sasada Yoshio
Published: July 2006

In order to study adenine-amide interactions, 3-(adenin-9-yl)propionamide has been synthesized and its crystal structure examined. The crystals are monoclinic, the space group being P21/a, with unit-cell dimensions of a=25.668 (1), b=8.025 (1), c=4.684 (1) Å, β=103.54 (1)°, and Z=4. The adenine bases are linked along the two-fold screw axis through the hydrogen bonds, N(6)H···N(1) and N(6)H···N(7). The amide group is hydrogen-bonded to N(3) of adjacent adenine moiety, the distance NH···N(3) being 3.055 Å. The model fitting by computer graphics indicates that this binding scheme could be an elementary interaction pattern between the amide group in protein and adenine in the minor groove of double helical DNA.
Energy Conversion and Storage in Solid-state Photogalvanic Cells
Authors: Hada Hiroshi , Takaoka Kazuchiyo , Saikawa Masahiko , Yonezawa Yoshiro
Published: July 2006

The solid-state photogalvanic cells involving photochemically deposited metals as active materials are presented. As these cells have many excellent features as compared with usual photogalvanic cells in which both the cathodic and anodic materials are dissolved in solution, they will promise a novel storage system for the conversion of solar energy to electrical energy. A typical two-compartment cell: TiO2, aqueous Ce(SO4)2–Ce2(SO4)3||aqueous AgNO3, Pt could be charged by the irradiation of 300–400 nm light on TiO2. The deposited silver on a platinum black storage electrode has almost the same electrochemical properties as the silver metal electrode and is capable of recharging after a nearly complete discharge.
Use of Propagators in the Hückel Model. II. Propagators in Terms of Trigonometrical Functions
Authors: Aono Shigeyuki , Ohmae Takayuki , Nishikawa Kiyoshi
Published: July 2006

The propagators of the chain molecules with and without the bond alternation are expressed in terms of trigonometrical functions. These expressions are convenient to practical manipulations. For exercises, the total energy, charge density and bond order are calculated.
Raman Scattering and Phase Transition of Ammonium Nitrates
Authors: Akiyama Kenji , Morioka Yoshiyuki , Nakagawa Ichiro
Published: July 2006

Polarized Raman spectra of single crystals are observed for the room-temperature phase NH4NO3(IV). The spectra in the low-frequency lattice vibration region as well as in the internal vibration region are well interpreted based on D2h13 structure. Raman spectra of powdered samples are measured at various temperatures covering whole phases NH4NO3 I–V. A characteristic feature of Raman spectrum is clarified for each phase. An abrupt spectral change occurs in the phase transition, indicating a first order transition. The splitting of Ag and B1g components of ν3 (asymmetric stretching mode of NO3− ion) in NH4NO3 is quite large, due to the strong interionic interaction between NH4+ and NO3− ions.
Raman Scattering and Phase Transition of NH4NO3–KNO3 Mixed Crystals
Authors: Akiyama Kenji , Morioka Yoshiyuki , Nakagawa Ichiro
Published: July 2006

NH4NO3–KNO3 mixed crystals, (NH4)xK1−xNO3 (x=0.88, 0.75, and 0.61), are prepared by evaporation of aqueous solutions of ammonium nitrate and potassium nitrate. Polarized Raman spectra of single crystals of mixed crystals are observed at room temperature and are interpreted based on the NH4NO3(III) type D2h16 structure. Raman spectra of powdered samples are examined at various temperatures and it is shown that the NH4NO3-(IV) type phase which is a room-temperature phase of NH4NO3 is not realized in the mixed crystals. In (NH4)0.88-K0.12NO3, NH4NO3(III) type is converted to NH4NO3(V) type around −120 °C. In the spectra of high-temperature phase of mixed crystals, only one broad band in the region 100 cm−1 −120 cm−1 is observed, which corresponds to KNO3(I) or KNO3(III) type structure.
Absorption Spectra of New Oxomolybdenum(V) Complexes of Tetraphenylporphyrin with Univalent Ligands
Authors: Imamura Taira , Numatatsu Takayuki , Terui Masashi , Fujimoto Masatoshi
Published: July 2006

New tetraphenylporphyrin complexes, MoO(tpp)X (X=F, Br, BF4, NCO, N3, and NCS), are easily prepared from the complex, MoO(tpp)OC2H5, where TPP denotes meso-tetraphenylporphyrin. The complexes are confirmed to contain a central oxomolybdenum(V) group based on the IR and the ESR measurements. The visible absorption spectra of the complexes in dichloromethane have three main peaks, the Soret band, the α and the β bands. The degree of red shifts of the corresponding absorption maxima is found to increase in the order: X=OC2H5<BF4\simeqF<NCO<N3<NCS<Cl<Br, accompanied with the same order of the change in the ratio εα/εβ. The correlation is also observed between the red shifts of the absorption peak around 330 nm and those of the Soret band. The complexes, MoO(tpp)X, are classified to d-type hyperporphyrin.
Reaction Process between Zinc Oxide and Sulfur Dioxide in the Presence of Carbon
Authors: Yajima Akimasa , Matsuzaki Ryoko , Saeki Yuzo
Published: July 2006

The reaction products obtained by heating a mixture of ZnO and carbon in a SO2 stream at various temperatures were examined. The possible reactions during the above process were also examined. When a mixture of ZnO and carbon was heated in a SO2 stream, the formation of ZnS was observed above 600 °C. At 800 °C, all the ZnO used was converted to ZnS. Sulfur was also obtained outside the heating zone, and its amount increased markedly above ca. 750 °C. The ZnS formed was a mixture of α-ZnS and β-ZnS regardless of the reaction temperature. The process of formation of ZnS can be represented as follows: the reaction between carbon and SO2 occurs at first to form sulfur. Above ca. 600 °C, the reaction between ZnO and the sulfur occurs to form ZnS. In addition to these reactions, the reduction of ZnO with carbon occurs slightly to form zinc, which then reacts with sulfur to form ZnS.
Catalytic Polarographic Wave of Fe(II) in Neutral Thiocyanate Solutions at Dropping Mercury Electrode
Authors: Himeno Sadayuki , Saito Atsuyoshi
Published: July 2006

The electrochemical behavior of Fe(II) in neutral thiocyanate solutions has been investigated at a dropping mercury electrode (DME). It was found that Fe(II) in neutral thiocyanate solutions gave a catalytic polarographic wave at potentials prior to the main Fe(II) reduction wave. The mechanism of the catalytic process involves the chemical reduction of thiocyanate ions with Fe(OH)2,aq at the electrode surface. Controlled potential electrolysis suggests that the reduction of thiocyanate ions proceeds with the formation of sulfide and cyanide ions. Sulfide ions produced at the electrode surface can react with Fe(II) diffusing to the electrode to form FeS. The discharge of this is responsible for the catalytic current, while cyanide ions have no essential role in the catalytic process. The effects of surface active substances and iodate ions on the catalytic wave are also discussed.
Oxidized Rubredoxin Models. Iron(III) Complexes of Z–Cys–Ala–Ala–Cys–OMe and Z–Ala–Cys–OMe
Authors: Ueyama Norikazu , Nakata Michio , Nakamura Akira
Published: July 2006

Oxidized rubredoxin models using Fe(III) ion and cysteine-containing peptide as Z–Cys–Ala–Ala–Cys–OMe were synthesized in solution and characterized by the absorption, CD, MCD, and EPR spectra. The Fe(III)/Z–Cys–Ala–Ala–Cys–OMe complex exhibits similar CD spectra as well as absorption, MCD, EPR spectra to native oxidized rubredoxin. Thus, the model complex has a similar electronic configuration and core structure to that of native protein. From the comparison with the result of Fe(III)/Z–Ala–Cys–OMe complex, the tetrapeptide complex probably has a relatively stable chelate structure with the hairpin turn conformation of the tetrapeptide.
Reaction of Dimeric Copper(II) Acetate with Pyridine and Quinoline Bases in Dioxane
Authors: Hasegawa Kazuo , Nakasuka Noriyuki , Tanaka Motoharu
Published: July 2006

Copper(II) acetate reacts with pyridine and quinoline bases in dioxane giving rise to adduct compounds, which were characterized by UV and EPR techniques. The reaction is formulated as follows:

Cu2(OAc)4+L\oversetK21\ightleftharpoonsCu2(OAc)4L,

where L denotes a free base and K21 is an adduct formation constant. Values of K21 range from 12 for quinoline or 2-picoline to 146 mol−1 dm−3 for 4-ethylpyridine. A linear free energy relationship is observed between the adduct formation and the protonation of bases in water except for sterically crowded bases.
Synthetic Studies of Rifamycins. III. The Partial Synthesis of Rifamycin Ansa-chain Compounds from Their Degradation Products
Authors: Nakata Masaya , Sakai Toshiya , Tatsuta Kuniaki , Kinoshita Mitsuhiro
Published: July 2006

The ansa-chain compound methyl [methyl 2,4,6,8,10,11,12,13,14-nonadeoxy-4,6,8,10,14-penta-C-methyl-3-O-methyl-l-manno-β-d-galacto-(11E,13Z)-11,13-pentadecadienopyranosid]uronate (1a) and its (R)-2-bromo derivative, 1b, were transformed into the corresponding 7,9-diacetate 3a and 3b or the 7,9-acetonide 7a and 7b. The ozonolysis of 3a or 3b gave methyl 7,9-di-O-acetyl-2,4,6,8,10-pentadeoxy-4,6,8,10-tetra-C-methyl-3-O-methyl-l-manno-β-d-galacto-undecodialdopyranoside-(1,5) (4a) or its (R)-2-bromo derivative (4b) respectively. The Wittig condensation of 4b with (methoxycarbonylmethylene)triphenylphosphorane, followed by debromination with tributylstannane, afforded methyl [methyl-7,9-di-O-acetyl-2,4,6,8,10,11,12-heptadeoxy-4,6,8,10-tetra-C-methyl-3-O-methyl-l-manno-β-d-galacto-(E)-11-tridecenopyranosid]uronate (6a). The diisobutylaluminium hydride reduction of 6a, followed by acetonation, gave methyl 2,4,6,8,10,11,12-heptadeoxy-7,9-O-isopropylidene-4,6,8,10-tetra-C-methyl-3-O-methyl-l-manno-β-d-galacto-(E)-11-tridecenopyranoside-(1,5) (10a). The allylic alcohol, 10a, was converted into the allylic bromide, 12a, which then yielded the triphenylphosphonium bromide, 13a. The Wittig condensation of the reactive ylide generated from 13a with methyl pyruvate afforded a 4 : 5 mixture of 7a and its 13E-isomer. The partial synthesis of 1a was accomplished by the selective hydrolysis of the 7a isolated from the mixture.
Synthetic Studies of Rifamycins. IV. The Synthesis of Rifamycin Ansa-chain Compound Using Carbohydratet
Authors: Nakata Masaya , Takao Hideaki , Ikeyama Yutaka , Sakai Toshiya , Tatsuta Kuniaki , Kinoshita Mitsuhiro
Published: July 2006

3-O-Benzyl-2,4,7-trideoxy-5,6-O-isopropylidene-2,4-di-C-methyl-l-glycero-d-galacto-heptose (6) was synthesized through 16 steps from 4,6-O-benzylidene-3-deoxy-3-C-methyl-α-d-altropyranoside (7). The condensation of 6 with methyl 2,4,6,7-tetradeoxy-6-lithio-4-C-methyl-3-O-methyl-α-l-arabino-(E)-6-heptenopyranoside, derived from 7, afforded a mixture (25) of methyl 9-O-benzyl-2,4,6,8,10,13-hexadeoxy-11,12-O-isopropylidene-4,8,10-tri-C-methyl-3-O-methyl-6-methylene-l-glycero-d-galacto-β-d-galacto-tridecopyranoside and its α-l-altro epimer in a 61% yield. The debenzylation of 25 by hydrogenolysis with palladium black, followed by homogeneous hydrogenation with tris(triphenylphosphine)chlororhodium(I) and the chromatographic isolation of the desired diastereomer, gave, after acetylation, methyl 7,9-di-O-acetyl-2,4,6,8,10,13-hexadeoxy-11,12-O-isopropylidene-4,6,8,10-tetra-C-methyl-3-O-methyl-l-threo-l-manno-β-d-galacto-tridecopyranoside-(1,5) (3) in a 19% yield. The hydrolysis of 3 followed by periodate oxidation and Wittig condensation with (methoxycarbonylmethylene)triphenylphosphorane, affords in a 79% yield, methyl [methyl 7,9-di-O-acetyl-2,4,6,8,10,11,12-heptadeoxy-4,6,8,10-tetra-C-methyl-3-O-methyl-l-manno-β-d-galacto-(E)-11-tridecenopyranosid]uronate, which is convertible into the title compound.