bluuebunny/crossref_metadata_2025 huggingface dataset:
Regio- and Stereoselective Cross-aldol Reactions via Dialkylboryl Triflates
Authors: Inoue Tan , Mukaiyama Teruaki
Published: July 2006

New borylating reagents, (Bu2BOTf and 9-BBNOTf), were prepared in high yields. The triflates reacted with enolizable ketones in the presence of tertiary amines to generate selectively one of the regioisomers of vinyloxyboranes by the choice of the reagents (the dialkylboryl triflates and tertiary amines) under mild reaction conditions. Vinyloxyboranes thus generated showed remarkable reactivity toward aldehydes to give only one regioisomer of the corresponding cross-aldols in good yields. High stereoselectivity was also observed in these reactions.
Simple Topological Theory of Aromaticity for Annulenes and Radialenes
Authors: Aihara Jun-ichi
Published: July 2006

Simple theory of aromaticity for annulenes and radialenes is developed by means of generalized total π-electron energy indexes, and is used to rationalize thermochemical stability and diamagnetic susceptibility exaltation of these compounds.
The Reactions of 2-Phenyl-2H-1-benzopyrans and 2-Phenyl-4H-1-benzopyrans with Lead(IV) Acetate
Authors: Kurosawa Kazu , Yamaguchi Katsutoshi , Nagata Yasuyuki , Ohki Hisatake
Published: July 2006

The reactions of 7-methoxy-2-phenyl-2H-1-benzopyran and 7-methoxy-2-phenyl-4H-1-benzopyran with lead(IV) acetate gave 2-benzoyl-6-methoxybenzofuran and 6-acetoxy-3-methoxy-6-(3-oxo-3-phenyl-1 -propenyl)-2,4-cyclo-hexadien-1-one. The reactions of 7-methoxy-2-(p-methoxy-phenyl)-2H-1-benzopyran and 7-methoxy-2-(p-methoxyphen-yl)-4H-1-benzopyran with lead(IV) acetate also gave the corresponding benzofuran and cyclohexadienone. The reaction pathway is discussed.
The Energy Dependence of Selective Hydrogen Atom Abstraction by H(D) Atoms in the Photolysis of Neopentane–Ethane Mixtures at 77 K
Authors: Miyazaki Tetsuo , Guedes Selma Matheus Loureiro , Fueki Kenji
Published: July 2006

Selective hydrogen-atom-abstraction reaction by an H or D atom has been studied in a neo-C5H12–C2H6 (less than 1 mol%) mixture at 77 K by ESR spectroscopy. The H (or D) atom produced by the photolysis of HI (or DI) reacts with neo-C5H12 and C2H6 to form neo-C5H11 and C2H5 radicals. In order to obtain H atoms with different kinetic energies, the photolysis was performed with different lights of 313, 254, and 229 nm. The selective formation of the C2H5 radical by the reaction of the H (or D) atom with C2H6 becomes more effective with the decrease in the energy of the H (or D) atom. The formation of the neo-C5H11 radical by the reaction of the H (or D) atom with neo-C5H12 becomes more effective with the increase in the energy of the H (or D) atom.
Novel Synthetic Reactions Using Bis(2,2,2-trifluoroethoxy)diorganosulfuranes
Authors: Kitazume Tomoya , Ishikawa Nobuo
Published: July 2006

Alkoxy- or acyloxysulfuranes prepared in situ by the ligand exchange of bis(2,2,2-trifluoroethoxy)diorganosulfuranes with alcohols or carboxylic acids were found to behave as a potential alkylating or acylating reagent for the preparation of unsymmetrical sulfides, ketones, and esters.
The Crystal Structure of Tetra-μ-acetato-diruthenium Chloride
Authors: Togano Tadashi , Mukaida Masao , Nomura Terunosuke
Published: July 2006

The crystal structure of Ru2(OCOCH3)4Cl has been determined from visually estimated Cu Kα data. The crystal is composed of the dinuclear, carboxylato-bridged species Ru2(OCOCH3)4+ and the bridging chloride anions. The molecular structure is almost identical with that of the analogous butyrato complex, but the chloridebridged chains run parallel with the c axis only.
Studies on the Solvent Extraction of Metal Perchlorates. II. Extraction of Alkali Metal Perchlorates with Trioctylphosphine Oxide
Authors: Kusakabe Satoshi , Sekine Tatsuya
Published: July 2006

Solvent extraction of alkali metal ions in 1 mol dm−3 sodium perchlorate ionic media with trioctylphosphine oxide (TOPO) in hexane was measured. The extraction improved in the order Li(I)>Na(I)>K(I)>Rb(I)>Cs(I). This was explained in terms of the higher ability of solvation with TOPO of the smaller ions. The chemical form of the extracted species was M(TOPO)n+(ClO4)−, where n is three for Li(I), Na(I), and K(I) and three and four for Rb(I) and Cs(I).
Thermochromism of Metal Chelates with Triphenylmethane Complexons in Aqueous Solutions. III. Copper(II)–Methylthymol Blue and –Methylxylenol Blue Systems
Authors: Nakada Shoji , Yamada Mutsuo , Ito Tasuku , Fujimoto Masatoshi
Published: July 2006

Reversible thermochromisms of copper(II) complexes with 3,3′-bis[bis(carboxymethyl)aminomethyl]thymol-sulfonphthalein (Methylthymol Blue; MTB) and 3,3′-bis[bis(carboxymethyl)aminomethyl]-p-xylenolsulfonphthalein (Methylxylenol Blue; MXB) were studied in aqueous solutions. The thermochromisms of these complexes were primarily ascribed to the temperature-dependence of the protolytic equilibria between a complex species AH having an uncoordinated free phenolic hydroxyl group and a complex species A having a coordinated phenolate group: AH\ightleftarrowsA+H. The equilibrium constants K of the reactions at 25 °C were determined to be p(K/mol dm−3)=4.66 for Cu(II)–MTB and 4.78 for Cu(II)–MXB. The thermodynamic parameters ΔH and ΔS for the reactions were calculated to be 26±2 kJ mol−1 and −6±3 J K−1 mol−1 (298 K) for both complexes, respectively. The rate constants of the proton dissociation of the phenolic hydroxyl group in the complexes AH were estimated to be 1.6×105 and 1.8×105 s−1 for Cu(II)–MTB and Cu(II)–MXB, respectively. The thermodynamic and kinetic data are discussed in terms of the effects of the substituents in the ligand molecules on the thermochromism.
Preparation and Properties of Nitrosyl Complexes of Molybdenum
Authors: Tatsumi Takashi , Sekizawa Kazuhiko , Tominaga Hiroo
Published: July 2006

Reactions of some dpe(dpe=Ph2PCH2CH2PPh2) complexes of molybdenum with nitrosyl hexafluorophosphate (NOPF6) have been investigated. The reaction of MoH4(dpe)2 with NOPF6 in benzene-methanol affords two types of complexes, a protonated species, trans-[MoF(HNO)(dpe)2]PF6 (1a) and a non-protonated species, trans-MoF(NO)(dpe)2·1/2C6H6. From the nitroxyl complex 1a, a series of nitrosyl complexes has been obtained. Some nitrosyl complexes exhibit cis-trans isomerism. Reactions of the nitrosyl complexes with protonic acids afford the corresponding nitroxyl complexes or the anion substitution products. Cationic nitrosyl complexes are obtained by the reactions of Mo(CO)L(dpe)2 (L=N2 or C2H4) and Mo(C2H4)2(dpe)2 with NOPF6. Attempts were also made to prepare nitrosyl complexes of molybdenum by use of other nitrosylating agents.
The Sensitized Photooxidation of Methoxycycloheptatrienes. The Synthesis of α-, β-, and γ-Tropolones
Authors: Yagihara Morio , Kitahara Yoshio , Asao Toyonobu
Published: July 2006

The sensitized photooxidation of 7-methoxycycloheptatriene (7-methoxytropilidene) afforded [4+2] cycloadduct (2), tropone, benzaldehyde and their 2-methoxy derivatives. Thermal isomerization of 2 followed by the treatment with alumina yielded 4-methoxytropone. The photooxidation of 1-methoxytropilidene gave 4-hydroxytropone and o-methoxybenzaldehyde, and the photooxidation of 3-methoxytropilidene followed by the treatment with triethylamine afforded 3-methoxytropone, tropone, and o-methoxybenzaldehyde. Characterization of the products and the mechanisms of the reactions are discussed.
The Temperature Dependence of Carbon-13 Chemical Shifts of Retinal Isomers and Their Related Compounds
Authors: Hanafusa Yoshito , Toda Masakazu , Inoue Yoshio , Chûjô Riichiro
Published: July 2006

The temperature dependence of carbon-13 chemical shifts has been studied for retinal isomers, N-all-trans-retinylidenebutylamine(all-trans-NRB) and N-all-trans-retinylidenebutylammonium chloride (all-trans-NRB·HCl). The change in the chemical shift was discussed in terms of the temperature dependences of the polarizability and conformation of the polyene-chain. In 11-cis-retinal, the coplanarity between the two parts of polyene-chain separated by the cis bond increases with a lowering of the temperature. The equilibrium between 12-s-cis and 12-s-trans conformers in 11-cis-retinal was studied and it was shown the latter conformer is preferable at low temperatures. In all-trans-NRB and all-trans-NRB·HCl, the temperature dependences of the chemical shifts are similar to those in all-trans-retinal. The extents of the chemical shift changes are in the following order: NRB·HCl<NRB<retinal. This trend can be correlated with the order of the red shifts of the absorption spectra.
Additivity Parameters for Anodic Peak Potentials in [2.2]Metacyclophanes and Tetrahydropyrene Formation
Authors: Torizuka Koichi , Sato Takeo
Published: July 2006

The first anodic peak potentials Epa(O1) for sixteen [2.2]metacyclophanes were surveyed in order to correlate the peak potential with the number and position of the alkyl groups. The analysis of the data gives the additivity parameters, which call for cathodic shifts of 0.14 and 0.035 V per methyl group for R2 or R5 (5- or 13-position) and for substitution at the rest of the positions respectively. The controlled-potential electrolysis of the representative metacyclophanes gave excellent yields of the corresponding tetrahydropyrenes.
Hydrates of Organic Compounds. V. The Clathrate Hydration of Alcohols
Authors: Nakayama Haruo , Hashimoto Masayuki
Published: July 2006

A new method for examining the ability of a given substance to form a hydrate with the same structure as that of a reference substance has been established. By using this method, for a series of alcohols ranging from methyl alcohol to pentyl alcohol, including their isomers, the ability to form a clathrate hydrate of either Structure I or Structure II has been investigated. It has been found that: (1) methyl alcohol has the ability to form both Structure I and II hydrates; (2) ethyl alcohol has the ability to form a Structure II hydrate; (3) all C3-alcohols (propyl, isopropyl, allyl, and propargyl alcohol) can actually form Structure II hydrates with relatively high (around −10 °C) incongruent melting points, and (4) among the C4- and C5-alcohols, only t-butyl alcohol has the ability to form a Structure II hydrate. However, it is uncertain for methyl and ethyl alcohols whether they actually can form such hydrates even in the absence of a reference substance. These results strongly suggest that the size and/or shape limitation plays an important role in the formation of alcohol hydrates with a gas-hydrate structure, just as has been found for the formation of ether and ketone hydrates.
The Raman Spectra of Cobalt(III) Complexes. I. Differentiation between cis and trans Isomers of Bis(ethylenediamine)cobalt(III) Complexes
Authors: Kanamori Kan , Kawai Kiyoyasu
Published: July 2006

The Raman spectra of bis(ethylenediamine)cobalt(III) complexes have been studied with a view toward differentiating between the cis and trans configurations. It is shown that a correlation can be made between the configurations of the complexes and the intensity of the band due to the chelate-ring-deformation vibration, δ(cycle). Thus, trans isomers exhibit a strong and sharp band near 270 cm−1 due to this mode, while cis isomers exhibit no intense band at this frequency.
Branched-chain Sugars. XX. Kinetic Studies on the Epimerization of 1,2 : 5,6-Di-O-isopropylidene-3-C-nitromethyl-α-d-allofuranose
Authors: Sato Ken-ichi , Koga Kenji , Hashimoto Hironobu , Yoshimura Juji
Published: July 2006

A study was made on the kinetics of the epimerization of 1,2: 5,6-di-O-isopropylidene-3-C-nitromethyl-α-d-allofuranose in nitromethane to its 3-epimer in the presence of a small amount of sodium methoxide. The activation energy was found to be 75±8 kJ/mol, the intermediate in epimerization being 1,2: 5,6-di-O-isopropylidene-α-d-ribo-hexofuranos-3-ulose with use of the labelled compound.
Functionalization of trans-Decalm. IV. A Stereoselective Synthesis of dl-β-Costol, dl-Arctiol, and the Related Eudesmane Type Sesquiterpenes
Authors: Torii Sigeru , Inokuchi Tsutomu
Published: July 2006

The efficient synthetic procedures to dl-β-costol (1a), dl-arctiol (2), and the related eudesmane type sesquiterpenes are described. trans-8,8-Ethylenedioxy-4aβ-methyldecalin-2α-ol (6a), prepared from trans-1,1-ethylenedioxy-4aβ-methyl-Δ6,7-octalin by epoxidation and subsequent reduction of the epoxy ring, was converted into 1a as follows: (1) deacetalization of 6a followed with mesylation, giving 2α-methylsulfonyloxy-4aβ-methyldecalin-8-one (7b), (2) condensation of 7b with methyl sodiomalonate and subsequent Wittig reaction with methylenetriphenylphosphorane affording dimethyl (trans-4aβ-methyl-1-methylene-7β-decalinyl)malonate (9), (3) reduction of sodium salt of 9 with NaAl(OCH2CH2OMe)2H2. Oxidation of 1a with PCC gave dl-β-costsd. dl-Arctiol (2), structurally related to 1a, was prepared from trans-5,5-ethylenedioxy-8aβ-methyldecalin-2-one. Introduction of two equatorial substituents, such as hydroxyl and 1-hydroxy-1-methylethyl groups at the C-2 and C-3 carbons of 2, was carried out as follows: (1) methoxycarbonylation followed by methylation of the sodium salt of keto ester with MeLi, (2) subsequent reduction with lithium in liquid NH3, giving trans-5,5-ethylenedioxy-3β-(1-hydroxy-1-methylethyl)-8aβ-methyldecalin-2α-ol (14), and (3) deacetalization of 14 followed by the reaction with methylenetriphenylphosphorane. dl-Eudesma-4(14),7(11)-dien-8-one was also prepared from 2 by oxidation with PCC followed by dehydration and subsequent isomerization of double bond.
Production of Furan by Vapor-phase Oxidation of Crotonaldehyde Using Heteropoly Compounds as Catalysts
Authors: Ai Mamoru , Tsai Tian-hsi , Ozaki Atsumu
Published: July 2006

The synthesis of furan by direct vapor-phase oxidation of crotonaldehyde has been studied. It was found that heteropoly compounds such as 12-molybdophosphoric acid are more effective than the mixed oxide (MoO3–P2O5, P/Mo=1/12) as catalyst for furan formation, and that the cesium salt of 12-molybdophosphoric acid with a Cs/Mo atomic ratio of 1/12 is more effective than the 12-molybdophosphoric acid catalyst. The rate of furan formation increases with increase in steam concentration in the feed, but is nearly independent of oxygen and crotonaldehyde concentrations. The yield of furan increases by decreasing the crotonaldehyde concentration, attaining 60 mol% at a concentration of 0.17 vol% in the feed. The conversion of crotonaldehyde at maximum yield is 90–95%.
Relationship between Chemical Selectivity and Melting Points of Reacting Molecules
Authors: Endo Tadashi , Takeda Yukiko , Orii Toyohiko , Kuwahara Akio , Ohta Masahiro , Sakai Miyuki , Okada Reiko , Hashimoto Masao
Published: July 2006

A relationship has been found to exist between the selectivity (the ratio of an unsymmetrical disulfide to symmetrical one) in the oxidation of a pair of associating thiols, 1-acyl-3-(2-sulfhydrylethyl)urea (1) and 1-(p-N,N-dimethylaminophenyl)-3-(sulfhydrylacetyl)urea, and the melting point of 1 in cases where 1 belongs to a homologous series.
Reaction between Aluminium Trichloride and Oxygen in the Vapor Phase and Properties of the Aluminium Oxide Formed
Authors: Shoji Yuichi , Tatsumi Kimikazu , Matsuzaki Ryoko , Saeki Yuzo
Published: July 2006

The reaction between gaseous AlCl3 and oxygen occurs at above ca. 400 °C and proceeds appreciably above ca. 800 °C to form Al2O3 and chlorine. The Al2O3 formed is amorphous Al2O3 at 800 °C, γ-Al2O3 containing amorphous Al2O3 at 900 and 950 °C, and γ-Al2O3 at 1000 °C. The phase transition of the Al2O3 formed is discussed.
Mechanistic Interpretations of the Dye-sensitized Formation of Hydrogen Peroxide in an Aqueous Solution
Authors: Usui Yoshiharu , Kobayashi Ei-jurou , Kazami Akira , Sakuma Shinobu
Published: July 2006

Kinetic studies of the photosensitized formation of hydrogen peroxide and hyperoxide ions in a mixed aqueous solution of eosine, oxygen, and EDTA have been attempted on the basis of a switch-over of the primary processes, i.e., the so-called DD, DR, and DO mechanisms. The rate constants for reactions of E+···E− and E+···O2− intermediates with oxygen and EDTA were obtained. The yield of hydrogen peroxide via the DO-initiated mechanism was enhanced as much as one order of magnitude (≈0.012) by the addition of 0.15 mol dm−3 of sodium borate or sodium carbonate. The maximum yield, 0.08, of hydrogen peroxide was obtained in an aerated aqueous solution of 1.0×10−4 mol dm−3 of eosine, 5.0×10−2 mol dm−3 of EDTA, and 8.8×10−2 mol dm−3 of sodium borate.
Formation of Sr2SiO4 and SrSiO3 from Strontium Silicate Hydrate Prepared by the Alkoxy Method
Authors: Yamaguchi Osamu , Ito Yoshifumi , Shimizu Kiyoshi
Published: July 2006

Sr2SiO4 and metastable SrSiO3 were formed directly at low temperatures from 3SrO·2SiO2·3H2O prepared by the alkoxy method. The transformation of metastable into stable SrSiO3 was observed at 900–980 °C. A kinetic study was made on the formation of Sr2SiO4.
Raman Spectra of Cobalt(III) Complexes. II. Nitroammine Series of Cobalt(III) Complexes
Authors: Kanamori Kan , Morikawa Tsutomu , Kawai Kiyoyasu
Published: July 2006

Solid and aqueous Raman spectra of the nitroammine series of cobalt(III) complexes, [Co(NO2)n(NH3)6−n](3−n)+ (n=1–6), have been measured for the region of 1500–100 cm−1. The assignments of the Raman bands due to the skeletal vibrations of the complexes have been made on an empirical basis and compared with those of the infrared bands in the literature.
A Potentiometric Study on Complex Formation of Silver(I) Ion with Glycine and β-Alanine in Aqueous Solution
Authors: Ohtaki Hitoshi , Zama Masayuki , Koyama Hidemi , Ishiguro Shin-ichi
Published: July 2006

The complex formation of silver(I) ion with glycine and β-alanine was studied at 25 °C in an aqueous solution containing 3 mol dm−3 LiClO4 as a constant ionic medium by means of potentiometric titrations. At a relatively low pH region, the AgHL+ complex (L− represents glycinate and β-alaninate ions) was formed, in which the silver ion was coordinated with the carboxyl group of the ligands. At a medium pH range, the AgL and AgL2− complexes were formed. From the formation constants of the complexes, it is suggested that the silver ion within the complexes may be coordinated with the amino group of the ligands and the interaction between the metal ion and the carboxyl group within the complexes is so weak that the interaction does not appreciably stabilize the complexes. At the highest pH region, the hydrolyzed species Ag(OH)L− was formed.
Reaction of Bis(dimethylglyoximato)(pyridine)styrylcobalt(III) Derivatives with Arenesulfenyl Chloride
Authors: Tada Masaru , Shinozaki Hiraku , Miura Kyo
Published: July 2006

cis-Styryl and trans-styryl-type cobaloximes, having a para-substituent on the styrene moiety, give the corresponding cis- and trans-(styrylthio) benzene derivatives in excellent yields by the reaction with 2,4-dinitrobenzenesulfenyl chloride. The substitution proceeds stereospecifically with retention of configuration except for the case of cis(p-cyanostyryl) cobaloxime.
A Facile Synthesis of 1,2-Divinylcycloalkanols and Their Behavior in the Oxy-Cope Rearrangement
Authors: Kato Tetsuya , Kondo Hisao , Nishino Masaki , Tanaka Minoru , Hata Go , Miyake Akihisa
Published: July 2006

The reaction of 2-chlorocycloalkanones with vinylmagnesium chloride gives 1,2-divinylcycloalkanols. Divinylation proceeds via a rearrangement of initially formed 2-chloro-1-vinylcycloalkanols to 2-vinylcycloalkanones followed by further vinylation of 2-vinylcycloalkanones. Thermal sigmatropic rearrangement of 1,2-divinylcycloalkanols gives 5-cycloalken-1-ones in good yields. The influence of the size of rings on the reaction pathways is discussed.
Transformation of D : A-Friedo-18β-lup-19-en-3-one into D : B-Friedo-18β,19αH-lup-5-en-3β-ol and a Comment on the Structure of Guimarenol
Authors: Yokoyama Yasushi , Moriyama Yoshihiko , Tsuyuki Takahiko , Takahashi Takeyoshi , Itai Akiko , Iitaka Yoichi
Published: July 2006

D:A-friedo-18β-lup-19-en-3-one was transformed into D:B-Friedo-18β,19αH-lup-5-en-3β-ol by two routes, 1) bromination-dehydrobromination of an enol benzoate of D:A-friedo-18β,19αH-lupan-3-one and 2) BF3·Et2O-catalyzed backbone rearrangement of 3β,4β-epoxy-D:A-friedo-18β, 19αH-lupane. The 18βH,19αH-configuration in these D:A- and D:B-friedo-type lupane derivatives was determined by means of X-ray diffraction for a 3α,4α-epoxide derived from D:A-friedo-18β,19αH-lupan-3β-ol. The synthetic D:B-friedo-18β,19βH-lup-5-en-3β-ol was found to be not identical with guimarenol isolated from Ceropegia dichotoma.
The Application of Magnetic Circular Dichroism to the Study of the Tautomerism of Cytosine and Isocytosine
Authors: Kaito Akita , Hatano Masahiro , Ueda Toru , Shibuya Susumu
Published: July 2006

The MCD and absorption spectra of cytosine and isocytosine and their N-substituted derivatives were measured in the wave-number region of 30000–50000 cm−1. On the basis of the experimental results, the tautomerism of cytosine and isocytosine was discussed. The transition energies, the oscillator strengths, and the Faraday B terms of the tautomeric forms of cytosine and isocytosine were calculated within the framework of the intermediate neglect of the differential overlap(INDO) approximation. The calculated results are in good agreement with the experimental data.
The Rate Constants of the Reactions of the Metastable Nitrogen Atoms, 2D and 2P, and the Reactions of N(4S)+NO→N2+O(3P) and O(3P)+NO+M→NO2+M
Authors: Sugawara Ko-ichi , Ishikawa Yo-ichi , Sato Shin
Published: July 2006

The pulse-radiolysis technique was used for the measurement of the quenching rates of the metastable nitrogen atoms, 2D and 2P, both in nitrogen and in helium. The rate constants obtained for N(2D) were (1.3±0.2)×10−14 cm3 molecule−1 s−1 (1 cm3 molecule−1 s−1=6.022×1017 m3 mol−1 s−1) in nitrogen and (4.6±0.4)×10−17 in helium; these values were larger than those for the higher energy metastable nitrogen atoms, N(2P), (3.3±0.3)×10−17 in nitrogen and (4.2±1.3)×10−18 in helium. The room temperature rate constants of the reactions of these atoms with nitrogen monoxide and with ethylene were also measured. All of these rate constants were found to be of the order of 3×10−11 cm3 molecule−1 s−1. The rate constants of the reactions, N(4S)+NO→N2+O(3P) and O(3P)+NO+M→NO2+M, were also measured and compared with literature values.
Interaction of 9-Aminoacridinium and 10-Methylacridinium Cations with Polyelectrolytes, with Emphasis on the Bound-dye Spectra
Authors: Yamaoka Kiwamu , Takatsuki Mineo , Nakata Kinya
Published: July 2006

Visible and UV absorption spectra of two dyes, 9-aminoacridinium (AA) and 10-methylacridinium (MeA) cations, were measured at 25 °C in the presence of three different polyelectrolytes—sodium salts of poly(p-styrenesulfonate) (NaPSS), polyphosphate (NaPP), and polyacrylate (NaPA)—for polymer residue-to-dye ratios from zero to near unity. The optical titration curves of AA-polyanion systems showed a slightly sigmoidal curvature. The method of extended principal component analysis was applied to the experimental spectra of the AA–NaPSS, –NaPP, –NaPA and MeA–NaPSS systems. Only two absorbing component dyes, i.e., bound and unbound, were verified to exist in each system. The equilibrium constant of the binding between dye and polyanion, the pure spectrum of bound dye, and the adjustable parameter α, by which the sigmoidal titration curve is characterized, were determined. In each of the above systems, the bound-dye spectrum behaves in opposition to the common notion of “metachromasy,” showing a bathochromic shift without any new band. The spectra of MeA changed only moderately by the addition of NaPSS. The ultrafiltration of the MeA–NaPP and –NaPA solutions confirmed that most of the MeA cations remain unbound.
The Micelle-promoted Selective Hydrolysis of Anionic and Nonionic Ester Substrates by Hydroxamic Acids and Histidine Derivatives
Authors: Ueoka Ryuichi , Matsuura Hidehiko , Nakahata Syuji , Ohkubo Katsutoshi
Published: July 2006

The hydrolyses of anionic 3-nitro-4-acyloxybenzoic acid (S2−–S16−) and nonionic p-nitrophenyl carboxylate (S2–S16) substrates catalyzed by hydroxamic acids (C6–C12) and histidine derivatives (AcetHis and LauHis) were performed with and without alkyltrimethylammonium (DTAC, CTAB, and OTAC) surfactants at pH 7.45. The present reaction was characterized by the selectively efficient hydrolysis of the same substrate of S6− or S10 by the comicellar Cm (m=8, 10, or 12)–CTAB (or OTAC) or LauHis–CTAB (or OTAC) catalysts. Relevant factors to such a selective hydrolysis of a specific substrate by the comicellar catalysts were discussed by taking notice of the electrostatic-charge-attraction force, steric hindrance, and hydrophobic interaction. The investigation of the binding constants in the present micellar reaction system demonstrated the importance of an appropriate hydrophobic interaction between a substrate and micelles for the selective rate enhacement of ester-hydrolysis.
Phase Transitions in N-Propylpyridinium–TCNQ Ion-radical Complex Salts
Authors: Murakami Mutsuaki , Yoshimura Susumu
Published: July 2006

N-Propylpyridinium (TCNQ)x crystallized in two complex salts (x=2, 2.5), both of which displayed initial irreversible and subsequent reversible first-order phase transitions with a sharp discontinuity in the electrical conductivity. The reversible transitions of both salts are essentially the same in spite of their differences in stoichiometry. The transitions were accompanied by crystal structure changes; the changes in the physical properties were ascribed to the crystalline distortion in both the one-dimensional TCNQ chain and the motion of the cation molecules. The high-temperature phase was metallic, with a zero activation energy for conduction; the source of the metallic behavior was also discussed. The electronic and infrared absorption spectra suggest that the high-temperature modification has a less distorted stacking of TCNQ molecules in the column.
The Heats of Solution of Optically Active Compounds and the Corresponding Racemic Compounds
Authors: Matsumoto Masayuki , Amaya Kazuo
Published: July 2006

The heats of solution of crystalline amino acids and hydroxy acid in water at 298.15 K were measured with a twin isoperibol calorimeter. It was found, as was expected from the theory, that the difference in the heat of solution between optically active compounds and their corresponding racemic compounds was appreciably large compared with the heat of mixing of concentrated aqueous solutions of d- and l-optical isomers.
Thermal Decomposition Reactions of Analogous Penta-amminenitrosylcobalt(III) Complexes
Authors: Miyokawa Kikuo , Masuda Hakaru , Masuda Isao
Published: July 2006

The thermal behavior of five complexes, [Co(NH3)6]Cl3 (1), [Co(NH3)5NO2]Cl2 (2), [Co(NH3)5NO]Cl2 (3), [(NH3)5Co–N(O)–NO–Co(NH3)5]Cl4·2H2O (4), and [(NH3)5Co–NO–ON–Co(NH3)5]Cl4·4H2O (5), has been investigated. The pyrolysis-gaschromatographic technique has been successfully applied to the N2- and N2O analyses of the gases evolved on the pyrolysis of the complexes. The thermal decomposition of these complexes is characterized predominantly by the reduction process of Co(III) to Co(II). In the simple nitrosyl 3, the NO− group reduces the Co(III) ion and dissociates as NO. As for the remaining complexes, a thermally induced transient-state tends to dissociate H+ from the coordinated ammonia as follows : CoIII–NH3→[CoIII–NH2δ−···Hδ+]→CoII+NH2+H+. The NH2 species is subsequently decomposed as NH2→2/3NH3+1/6N2. Moreover, H+ is captured by an anionic species and/or the NH3 present in the system, that is, by Cl− and NH3 forming NH4Cl in the case of 1, by NO2− and NH3 forming NH4NO2, which then decomposes to N2 and H2O, in 2, and by N2O22− forming H2N2O2, which then decomposes to N2O and H2O, in 4. The 5 complex undergoes an exothermic decomposition, affording a larger amount of N2 and N2O than those to be expected from the above stoichiometry, suggesting an oxidative behavior of the bridged, dimeric (–NO–ON–)2− group towards ammonia.
The Conformations of 2-Phenylpropionaldehyde and Some Aliphatic Ketones. The Possible Importance of the CH/π and CH/n Interactions in Determining the Molecular Geometry of a Mobile System
Authors: Zushi Shoji , Kodama Yoshio , Nishihata Ken , Umemura Koshiro , Nishio Motohiro , Uzawa Jun , Hirota Minoru
Published: July 2006

The conformations have been studied by means of NMR spectroscopy, largely by the computer simulation of the lanthanoid-induced shifts, for a series of aliphatic carbonyl compounds with the following structures: CH3CH(C6H5)CO–R; R=H, CH3, C2H5, i-C3H7, and t-C4H9. It has been suggested that two rotamers are important in the conformational equilibria of these ketones, in which the R–C–C–C6H5 dihedral angle is ca. 30° and ca. 90°. The relative stability of the above two rotamers has been found to depend on the nature of the alkyl group, R. The results have been discussed in light of the possible weak attractive forces, the CH/π and CH/n interactions.
Dynamic Behavior and Nature of Active Sites Directly Observed by Means of Photoluminescence Spectroscopy
Authors: Iwasawa Yasuhiro , Ogasawara Sadao
Published: July 2006

The dynamic behavior and properties of the active sites (Types I, II, and III) of SiO2-supported Mo catalysts during a redox reaction with H2 or O2 (in connection with a general two-stage redox mechanism) were observed directly by means of a photoluminescence technique.
Catalysis by Heteropolyacid. V. Catalytic Alkylation of Toluene by Mixed-coordination type, H4[SiMo12−nWnO40], Heteropolyacid
Authors: Nomiya Kenji , Saijoh Hidehiko , Miwa Makoto
Published: July 2006

To compare the specific difference between molybdenum and tungsten ions on the catalytic reaction, we investigated the alkylation of toluene with benzyl chloride by mixed-metal heteropolyacids, H4[SiMo12−nWnO40] (n=0, 1, 10, and 11). Molybdenum-rich compound is more active than tungsten-rich one.
The Direct Alkylamination of 1-Aminoanthraquinone Promoted by Cobalt(II) Chloride
Authors: Yoshida Katsuhira , Matsuoka Masaru , Yamashita Yoshio , Nagamori Shoichi , Kitao Teijiro
Published: July 2006

The reaction of 1-aminoanthraquinone with primary aliphatic amines in the presence of cobalt(II) chloride under atmospheric oxygen preferentially gave the corresponding 1-amino-4-(alkylamino)anthraquinones. The reaction did not proceed with aqueous ammonia, bidentate amines, secondary aliphatic amines, and primary arylamines. While, with alicyclic amines the reaction mainly afforded 1-amino-2,4-bis(alkylamino)anthraquinones.
Kinetics and Mechanism of Ligand Exchange of Tris(acetylacetonato)iron(III) in Acetylacetone
Authors: Kido Hiroaki , Saito Kazuo
Published: July 2006

Tris(acetylacetonato[2-14C])iron(III) undergoes ligand exchange in acetylacetone at 4–16 °C without side reactions. The exchange rate is expressed by Rate=(ka+kb[H2O])[complex]([complex]≈0.01 M, [H2O]≈0.05 M), and the rate constant (10.2 °C) and activation parameters are ka=(8.9±1.2)×10−4 s−1, ΔH\eweq=14.4±0.9 kcal mol−1, ΔS\eweq=−22±3 cal K−1 mol−1 and kb=(2.22±0.20)×10−2 M−1 s−1, ΔH\eweq=16.9±0.4 kcal mol−1, ΔS\eweq=−6.1±1.3 cal K−1 mol−1 (1 cal=4.18 J, 1 M=1 mol dm−3). No deuterium isotope effect on the rate. The rate-determining steps seem to correspond to the formation of intermediates containing a one-ended acac− and an Hacac molecule (the ka path), and the anion and a water molecule (the kb path), by the SN2 mechanism.
Syntheses and Reactions of Optically Active Alkoxyaminosulfonium Salts
Authors: Okuma Kentaro , Minato Hiroshi , Kobayashi Michio
Published: July 2006

The optically active methoxymorpholino-p-tolylsulfonium salt has been synthesized by the reaction of optically active N-p-toluenesulfinylmorpholine with methyl trifluoromethanesulfonate. The sulfonium ion methylated benzylethylphenylamine and benzyl ethyl sulfide with asymmetric induction to give the optically active benzylethylmethylphenylammonium ion and benzylethylmethylsulfonium ion respectively. The optically active methoxymorpholino-p-tolylsulfonium salt and diaminosulfonium salts have been prepared in a one pot reaction between N-p-toluenesulfenyImorpholine and 1-chlorobenzotriazole with methanol in the presence of 1-menthol at −80 °C.
Catalytic Property of Calcined Iron Sulfate Treated with Hydrogen Chloride in Alkylation of Toluene and Benzene with Alkyl Chlorides
Authors: Arata Kazushi , Hino Makoto , Yabe Katsumasa
Published: July 2006

Alkylation was carried out at room temperature over catalysts prepared by calcination of FeSO4, Fe2O3, and Fe(OH)3 in the air at various temperatures and subsequent exposure to HCl at room temperature for 20 min. The FeSO4–HCl catalysts heat-treated at 700 and 750 °C showed very high activity and selectivity, the other catalysts except for the sulfate treated at 800 °C being almost inactive. The FeSO4(700 °C)–HCl catalyst was found to consist of FeCl3 and α-Fe2O3 by means of Mössbauer effect, the absorption peak areas being 14 and 86% for portions of iron based on the chloride and oxide, respectively. The results of DTA and TGA experiments suggest that the coordinate bond of water molecule on FeCl3 of the FeSO4(700 °C)–HCl catalyst is stronger than that on FeCl3 of the FeSO4 (600, 800, and 900 °C)–HCl and commercial FeCl3. The FeSO4(700 °C)–HCl catalyst showed a much higher activity than pure FeCl3. The iron(III) chloride formed by reaction of HCl and α-Fe2O3 obtained by thermal decomposition of the sulfate at 700 or 750 °C was found to be a very strong Lewis acid catalyst.
The Crystal and Molecular Structure of Tetracyclo[6.4.3.0.02,7]pentadec-4-en-13-one
Authors: Koshibe Shigeru , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami
Published: July 2006

The X-ray molecular structure of the photocycloadduct of bicyclo[4.3.0]non-1(6)-en-7-one with 1,4-cyclohexadiene has been determined. The crystals belong to the monoclinic system, space group P21/c, Z=4, a=8.108(1), b=8.836(1), c=7.095(1) Å, and β=95.38(1)° at 22 °C; a=7.975(1), b=8.760(1), c=16.949(2) Å, and β=94.85(1)° at −160 °C. The structure was solved by the direct method and refined by the least-squares procedure to R=0.052 (22 °C) and 0.053 (−160 °C) for 1777 and 2349 non-zero reflections respectively. The ring junction between the four- and six-membered rings is trans. The molecule has the cis-anti-trans structure. No essential difference is observed between the molecular structure at 22 °C and −160 °C except for the thermal motions.
The Deuteron Magnetic Resonance of Tin(II) Chloride Dihydrate Single Crystals in High- and Low-temperature Phases
Authors: Kiriyama Hideko , Nakamura Osamu
Published: July 2006

The deuteron magnetic resonance spectra of SnCl2·2D2O single crystals have been measured from 208 to 300 K in order to elucidate the static and dynamic structures of water molecules in connection with the phase transition occuring at 234 K. The deuteron quadrupole coupling constants (asymmetry parameters) were determined at 208 K for four non-equivalent water deuterons. These values are 194.2±0.3 (0.066±0.004), 193.2±0.5 (0.112±0.003), 223.3±0.4 (0.206±0.003), and 244.0±0.4 kHz (0.058±0.003), depending largely on the hydrogen-bond strength or the D···O distance. The deuteron arrangements deduced from the EFG tensors agreed well with the ordered structure reported by an earlier ND study. The dynamical process of deuterons responsible for the high-temperature disordered structure was analyzed with the aid of the ND results and was ascribed to a combination of the flip motion of water molecules about each two-fold axis and their rotational motion around each pseudo-three-fold axis.
Precise Complexometric Coulometric Titration of Disodium Dihydrogen Ethylenediaminetetraacetate Dihydrate and Aluminium
Authors: Tanaka Tatsuhiko , Hotta Kousei , Yoshimori Takayoshi
Published: July 2006

The purity of recrystallized disodium dihydrogen ethylenediaminetetraacetate dihydrate was determined accurately by titration with zinc ion coulometrically generated from an amalgamated zinc anode. The reagents used were of 99.446% ±0.002% homogeneity when the sample was dehydrated and stored in a hygrostat (relative humidity, ca. 58% at 20 °C) over 1 year. Aluminium of high purity (99.99%) was coulometrically titrated with the purified reagent. Aluminium was allowed to react with a certain amount of the reagent, excess of the reagent being titrated with zinc ion anodically generated. The end point was determined potentiometrically using a mercury electrode. The purity was found to be 99.976% with a standard deviation of 0.010% for 6 degree of freedom. Cause of the lower result (0.01%) is discussed.
A Cation-exchange Study of Cerium(III) and Thulium(III) Tartrate Complexes
Authors: Ohyoshi Emiko , Ohyoshi Akira
Published: July 2006

The tartrate complexes of Ce(III) and Tm(III) were studied by the cation-exchange method, where a series of solutions prepared so as to keep the [Htart−] value nearly constant, while the [tart2−] value was varied, was used for the estimation of the protonated complexes. Three kinds of complexes, M(Htart)2+, M(Htart)(tart), and M(tart)2−, were found in the lower pH region of the solutions.
A Convenient Synthesis of Telluronium Ylides
Authors: Tamagaki Seizo , Akatsuka Ryuji , Kozuka Seizi
Published: July 2006

Several telluronium ylides were readily prepared by mixing the corresponding telluroxides and a variety of active methylene compounds in CHCl3 at ambient temperature or under reflux. Arylselenonium ylides could also be obtained in a similar way.
Kinetics and Mechanisms of Ligand Exchange Reactions of Tris(acetylacetonato)-chromium(III), -cobalt(III), -ruthenium(III), and -rhodium(III) in Acetylacetone
Authors: Kido Hiroaki
Published: July 2006

Tris(acetylacetonato[2-14C])-cobalt(III), -chromium(III), -ruthenium(III), and -rhodium(III) undergo ligand exchange in acetylacetone (Hacac) at 85–190 °C without decomposition of the complexes. The exchange rate is proportional to the complex concentration, and the first-order rate constant k0 decreases in the sequence Co(III)>Cr(III)>Ru(III)>Rh(III), k0⁄10−5 s−1 being 2.4 (93 °C), 5.6 (117 °C), 9.5 (158 °C), and 2.4 (185 °C), respectively. The activation enthalpies and entropies and deuterium isotope effect on k0 are significantly different between the Co(III) and the Cr(III), Ru(III) and Rh(III) complexes. An intermediate involving an one-ended acetylacetonate and a solvent molecule(Hacac) is concluded to be formed in the rate-determining step. The SN1 and the SN2 mechanism are assigned to the exchange reactions of the Co(III) complex and the others, respectively, for the rate-determining steps.
New Effective Nickel(II) Catalysts for the Cross-coupling of an Aryl Grignard Reagent with Aryl Halide
Authors: Ibuki Eiichi , Ozasa Shigeru , Fujioka Yasuhiro , Okada Motofumi , Terada Katsutoshi
Published: July 2006

It has been found that seventeen nickel complexes of the Ni–O4, Ni–S4, Ni–O2N2, Ni–O3N3, Ni–N4, Ni–N6, and Ni–(C5)2 types exhibit a high catalytic activity for the selective cross-coupling reaction of an aryl Grignard reagent with aryl iodide, which make possible the synthesis of unsymmetrical aromatics of a high purity and in a high yield.
Synthesis of 1-Substituted 3-(Dialkylaminoalkoxy)-4,5,6,7-tetrahydro-1H-indazoles
Authors: Soga Takeo , Niwa Hirosuke , Shiraishi Takanori
Published: July 2006

4,5,6,7-Tetrahydro-3-indazolone was prepared by catalytic hydrogenation of 3-indazolone, and its reaction with dialkylaminoalkyl chloride was studied. In addition, a number of 1-substituted 3-(dialkylaminoalkoxy)-4,5,6,7-tetrahydro-1H-indazoles were prepared.
Grignard Reaction of Peroxides Containing Neighboring Nitrogen Atom
Authors: Okubo Masao , Komatsu Takutomo , Tsuruta Ky\={o}ko , Sonoda Yasuyo
Published: July 2006

The substituent effect on the reaction of bis(2-aryl-1,2,3,4-tetrahydro-1-isoquinolyl) peroxide with PhMgBr as well as the product obtained on the reaction of 2-p-tolyl-1,2,3,4-tetrahydro-1-isoquinolyl t-butyl peroxide with PhMgBr were interpreted in terms of the coordination of the neighboring nitrogen atom to Mg atom.
A Nephelometric Analysis of Mercury(II) with Potassium Salt of α,α′-Bis(dithiocarboxyoxy)-p-xylene
Authors: Yamamoto Daijiro , Tsukada Masamichi , Hirota Yasuaki , Mizuno Haruo
Published: July 2006

Potassium salt of α,α′-bis(dithiocarboxyoxy)-p-xylene (abbreviated as K2-XDX) was synthesized as a chelating agent with p-xylene-α,α′-diol, carbon disulfide, and potassium hydroxide. Since a mercury(II)–XDX chelate complex suspension scattered pearl-blue light strongly because of the formation of a colloidal solution, the nephelometric analysis of small amounts of mercury(II) was undertaken. The calibration curve was found to be linear in the two ranges of 0.03–1.00 and 0.50–25.00 μg cm−3 of the mercury(II) ion respectively, but no suitable masking agents for interfering metal ions were found. The mole ratio of mercury(II) to XDX in the complex was found to be 1 to 1. These data for the complex suggested that XDX and mercury(II) combined alternately to form the (–Hg–XDX–)n complex. The molecular weight of this complex could be calculated as about 2×107 from the Zimm plot on the basis of the light-scattering method.
Optical Resolution by Preferential Crystallization and Replacing Crystallization of Dl-Allothreonine
Authors: Miyazaki Hideya , Morita Hiroyuki , Shiraiwa Tadashi , Kurokawa Hidemoto
Published: July 2006

The ternary solubility diagram, X-ray diffraction pattern, and infrared spectra have suggested that Dl-allothreonine [Dl-aThr] exists as a conglomerate. The optical resolution by successive preferential crystallization gave both d- and l-aThr of 95% optical purities in 9—13% degrees of resolution. The successive replacing crystallization was more successfully achieved by the coexisting 4-hydroxy-l-proline, as an optically active cosolute, in a racemic supersaturated solution. d-aThr of 94% optical purity was allowed to crystallize preferentially without seeding d-aThr in 24% degree of resolution, whereas l-aThr of 81% optical purity from the mother liquor was allowed to crystallize by seeding l-aThr in 22% degree of resolution. Recystallization of the obtained d- and l-aThr from water gave an optically pure form.
Facile Synthesis of Linear and Angular 2-Methylfurobenzopyranone
Authors: Rao Y Jayaprakash , Krupadanam G L David
Published: July 2006

A route for the synthesis of 2-methylfurobenzopyranone by the oxidative cyclization of sodium salt of 7-hydroxy-6 or 8-allyl-4H-[1]benzopyran-4-one using PdCl2(PhCN)2 complex has been developed.
Performance and Design of Mobility Allowance Shuttle Transit Services: Bounds on the Maximum Longitudinal Velocity
Authors: Quadrifoglio Luca , Hall Randolph W. , Dessouky Maged M.
Published: July 2006

We develop bounds on the maximum longitudinal velocity to evaluate the performance and help the design of mobility allowance shuttle transit (MAST) services. MAST is a new concept in transportation that merges the flexibility of demand responsive transit (DRT) systems with the low-cost operability of fixed-route bus systems. A MAST system allows buses to deviate from the fixed path so that customers within the service area may be picked up or dropped off at their desired locations. However, the main purpose of these services should still be to transport customers along a primary direction. The velocity along this direction should remain above a minimum threshold value to maintain the service attractive to customers. We use continuous approximations to compute lower and upper bounds. The resulting narrow gap between them under realistic operating conditions allows us to evaluate the service in terms of velocity and capacity versus demand. The results show that a two-vehicle system, with selected widths of the service area of 0.5 miles and 1 mile, is able to serve, respectively, a demand of at least 10 and 7 customers per longitudinal mile of the service area while maintaining a reasonable forward progression velocity of about 10 miles/hour. The relationships obtained can be helpful in the design of MAST systems to set the main parameters of the service, such as slack time and headway.
Post‐traumatic stress disorder and illness perceptions over time following myocardial infarction and subarachnoid haemorrhage
Authors: Sheldrick Russell , Tarrier Nicholas , Berry Elisabeth , Kincey John
Published: July 2006

Objectives. This study investigated post‐traumatic stress disorder (PTSD) symptoms and illness perceptions in people who suffered the acute medical trauma of a myocardial infarction (MI) or a subarachnoid haemorrhage (SAH). The study tested hypotheses regarding changes in PTSD symptoms and illness perceptions over time, associations between PTSD and illness perceptions and cognitive predictors of PTSD.

Design and method. The study employed a longitudinal design and measured the illness perceptions and PTSD symptoms of an MI group (N = 17) and a SAH group (N = 27). Data were collected within 2 weeks of admission (T1), 6 weeks after admission (T2) and 3 months after admission (T3). Statistical analysis was undertaken to examine associations between illness perceptions and PTSD and to examine cognitive predictors of PTSD.

Results. The prevalence of PTSD within the total acute medical trauma sample was 16% at 2 weeks, 35% at 6 weeks and 16% at 3 months. Illness perception factors of identity, timeline (acute/chronic), consequences and emotional representation were strongly correlated with PTSD at all three time points. PTSD symptoms and illness perceptions were shown to have changed over time. The results also showed that several illness perception factors are significant predictors of PTSD.

Conclusions. Both PTSD symptoms and illness perceptions changed significantly over time following an MI or SAH. Illness perception factors are significant predictors of PTSD.
Fuzzy Clustering of Raman Spectral Imaging Data with a Wavelet-Based Noise-Reduction Approach
Authors: Wang Yu-Ping , Wang Yong , Spencer Paulette
Published: July 2006

Raman spectral imaging has been widely used for extracting chemical information from biological specimens. One of the challenges is to cluster the chemical groups from the vast amount of hyperdimensional spectral imaging data so that functionally similar groups can be identified. In this paper, we present an approach that combines a differential wavelet-based data smoothing with a fuzzy clustering algorithm for the classification of Raman spectral images. The preprocessing of the spectral data is facilitated by decomposing them in the differential wavelet domain, where the discrimination of true spectral features and noise can be easily performed using a multi-scale pointwise product (MPP) criterion. This approach is applied to the classification of spectral data collected from adhesive/dentin interface specimens where the spectral data exhibit different signal-to-noise ratios. The proposed wavelet approach has been compared to several conventional noise-removal algorithms.