bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immobilized β-Cyclodextrins. Preparation with Various Crosslinking Reagents and the Guest Binding Properties
Authors: Sugiura Izuru , Komiyama Makoto , Toshima Naoki , Hirai Hidefumi 
Published: July 2006

Abstract
β-Cyclodextrin (β-CyD) was immobilized by crosslinking with 1,2-ethanediol diglycidyl ether, 1,4-buthanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,3-butadiene diepoxide, 1,7-octadiene diepoxide, and epichlorohydrin. The molar ratio of the crosslinking residue to β-CyD (degree of crosslinking) for each macromolecular product was determined by the corresponding elemental analysis. The equilibrium constant K of complex formation of each crosslinking macromolecule for cresols, phenol, nitrophenols, and 2-naphthol was determined, respectively, by the use of electronic absorption spectroscopy in pH 4 and 10 (or 11) buffer solutions. The concept of a hydrophobic enhancement coefficient R was introduced in order to compare the effect of a hydrophobic crosslinking residue upon the complex formation of the immobilized CyD.
The Determination of the Selectivity Coefficient of Na+ versus Li+ on Prussian Blue Thin Film in Propylene Carbonate by Means of a Quartz Crystal Microbalance
Authors: Aoki Katsunori , Miyamoto Takeshi , Ohsawa Yasuhiko 
Published: July 2006

Abstract
The cation selectivity on a Prussian Blue (PB) modified electrode in propylene carbonate was examined by means of a quartz crystal microbalance. It was found that the selectivity coefficient of Na+ versus Li+ on the PB film was about 15.
Formation of Solvent-Separated Ion Pairs in Calixarene Ester–Alkali Picrate Complexes
Authors: Arimura Takashi , Kubota Michio , Matsuda Tsutomu , Manabe Osamu , Shinkai Seiji 
Published: July 2006

Abstract
Association constants (Ka) of calix[n]arene esters (1n: n=4, 6, 8) for alkali picrates have been determined in tetrahydrofuran and compared with the 1n-induced bathochromic shifts of the absorption maxima of alkali picrates. It has been established that (1) 1n’s mostly form the 1 : 1 complexes with alkali metal cations, (2) the Ka values for 1n are generally smaller than those for crown ethers, and (3) the certain M+–1n complexes are considerably solvent-separated because of the “encapsulation effect” of the calixarene cavity. This is the first example for the systematic investigation on the relation between Ka and the geometry of the calixarene ester complexes.
The Preparation of Stable Colloidal Poly(vinyl alcohol) Composites of Cu2O and Cu
Authors: Yokoi Hiroshi , Kadowaki Akihide , Ikoma Shuji 
Published: July 2006

Abstract
Stable colloidal particles of reddish brown Cu2O–PVA and grayish black Cu–PVA composites have been prepared by the reduction of green Cu2+–PVA complexes in aqueous solutions with hydrazine, at the [hydrazine]/[Cu2+] ratios of 1–3 and 15 or more respectively, where PVA represents poly(vinyl alcohol). The average diameters of the Cu2O and Cu particles in these composites have been estimated to be about 200 and 300 Å respectively from the half widths of the X-ray diffraction peaks for the corresponding powder samples.
The Magnetic Predissociation of the B3Π0+u State of the Iodine Molecule
Authors: Baba Masaaki , Kimura Misako , Tsuboi Toshiyuki , Kato Hajime , Nagakura Saburo 
Published: July 2006

Abstract
It is shown that the predissociation of I2 excited to the B3Π0+u state can occur through the coupling with the 24311Πu state by gyroscopic and Zeeman interactions. The interaction matrix elements between the B3Π0+u and 24311Πu states are shown to be nonzero, for the 24311Πu state is mixed significantly with the 24313Π1u state by the spin-orbit interaction. The v, J dependence of the magnetic-quenching ratios of the B3Π0+u−X1Σ+g fluorescence intensity has been measured and analyzed. The rate constants of the magnetic predissociation in the B3Π0+u state have also been evaluated. The magnetic-field dependence of the hyperfine structure has been measured by means of the Doppler-free intermodulated fluorescence method.
Synthesis of 4-[(E)-1-Alkenyl]-2-hydroxybutanolides and (Z)-4-Alkylidene-2-butenolides through Cycloadditions Using a Phosphorus-Functionalized Nitrile Oxide
Authors: Kanemasa Shuji , Nakagawa Norihiko , Suga Hiroyuki , Tsuge Otohiko 
Published: July 2006

Abstract
A sequence of cycloadditions of (diethoxyphosphinyl)acetonitrile oxide with α,β-unsaturated esters, the Raney Ni reduction of the resulting cycloadducts, the Horner–Emmons olefination, and the carbonyl reduction with sodium borohydride leads to 5-[(E)-1-alkenyl]-3-hydroxy-4,5-dihydro-2(3H)-furanones which can be converted into (Z)-5-alkylidene-2(5H)-furanones in two steps.
Catalysis by Heteropoly Compounds. XIII. An Infrared Study of Ethanol and Diethyl Ether in the Pseudoliquid Phase of 12-Tungstophosphoric Acid
Authors: Lee Kwan Young , Mizuno Noritaka , Okuhara Toshio , Misono Makoto 
Published: July 2006

Abstract
Ethanol, diethyl ether, and water absorbed in, and their thermal desorption from, the pseudoliquid phase of 12-tungstophosphoric acid have been studied by means of infrared spectroscopy. For all three molecules, the state of the absorption of 6 molecules per anion, H3PW12O40·6R2O (R; C2H5 or H), was quite stable and the secondary structures were similar. The intensities of the C–H vibrations indicated that the methyl group of the ethanol molecules interacted with the anions and that its interaction became stronger as the amount of absorbed molecules decreased. In the thermal desorption of absorbed ethanol or diethyl ether, a protonated monomer and dimer as well as an ethoxy group were detected by means of infrared spectroscopy. These species are reaction intermediates of the dehydration of ethanol which were assumed previously (J. Am. Chem. Soc., 109, 5535 (1987)). It was also found that, upon the dehydration of H3PW12O40·6H2O, the proton which had been hydrogen-bonded to the oxygen atom of the water molecule ((H2O)2H+) migrated onto the bridging oxygen of the heteropoly anion (PW12O4O403−).
Interactions between the Tris(1,10-phenanthroline)iron(II) Cation and Anionic Surfactants: Diffusion and Conductance Studies
Authors: Tominaga Toshihiro , Maruyama Toru , Koshiba Takayuki , Yamamoto Yuroku 
Published: July 2006

Abstract
Tracer diffusion coefficients for the [Fe(phen)3]2+ cation (phen=1,10-phenanthroline) have been measured in aqueous solutions of sodium 1-hexane-, 1-octane-, 1-decane-, and 1-dodecanesulfonate (NaDSO) in concentration ranges below the critical micelle concentrations of the surfactants and at 298.2 K. The diffusion coefficient decreases with an increase in the concentration of the surfactants. At a fixed concentration, the diffusion coefficient decreases with an increase in the carbon number of the surfactants. The results are compared with our previous results in sodium dodecyl sulfate (NaDS) solutions. The conductivities of the NaDSO and NaDS solutions were also measured at 298.2 K in the presence and absence of [Fe(phen)3]SO4. In the presence of [Fe(phen)3]SO4, the molar conductivities of the surfactants first decrease, then increase, and finally decrease again with an increase in the concentration of the surfactants.
Thermal Isomerization of 1′,3′,3′-Trimethyl-8-nitrospiro[2H-1-benzopyran-2,2′-indoline]-6-carboxylic Acid
Authors: Nishimura Norio , Miyake Jun’ichi , Sueishi Yoshimi 
Published: July 2006

Abstract
The rates of thermal isomerization of 1′,3′,3′-trimethyl-8-nitrospiro[2H-1-benzopyran-2,2′-indoline]-6-carboxylic acid (6-COOH-8-NO2-SP) from its spiro form (SP) to its merocyanine form (MC) have been measured in some solvents and at high pressures. The equilibrium constants between these isomers at atmospheric pressure and at 30 °C are in the range of 0.25 to 2.52 depending on solvents. The activation volumes are 0.2–3.4 cm3 mol−1, while the reaction volumes are −7.9–−22.3 cm3 mol−1. Thus the volume profile was found to have a maximum, as predicted previously.
Comparison between Optical Properties of Sulfates and Hydrogensulfates in Halogen-Bridged Mixed-Valence Platinum(II, IV) Complexes
Authors: Matsushita Nobuyuki , Kojima Norimichi , Ban Toshiro , Tsujikawa Ikuji 
Published: July 2006

Abstract
Syntheses and optical properties of some new halogen-bridged mixed-valence platinum complexes analogous to Wolffram’s Red Salt, [Pt(en)2][PtBr2(en)2](HSO4)4 (PBHS), [Pt(en)2][PtI2(en)2](HSO4)4·4H2O (PIHS), and [Pt(en)2][PtX2](en)2](SO4)2·6H2O {X=Br(PBSW), I(PISW)}, are reported. The powder X-ray diffraction pattern shows that PBHS is isomorphous with [Pt(en)2][PtCl2(en)2](HSO4)4 (PCHS), and that PBSW and PISW are isomorphous. The hydrogensulfates PBHS and PIHS crystallize from an aqueous sulfuric acid solution, whereas the sulfates PBSW and PISW crystallize from an aqueous solution. The single crystal absorption spectra of PBHS, PIHS, PBSW, and PISW have been investigated at 4.2 K. The intense optical absorption due to intervalence charge-transfer transition from Pt(II) to Pt(IV) has been observed for the light polarized parallel to the Pt chain axis (E//chain). From the comparison of the energy of the intervalence charge-transfer absorption edges in PBHS, PBSW, and PISW, one can conclude that the influence of the substitution of the counterions HSO4− with SO42− on the Pt(II)–Pt(IV) mixed-valence state is no less better than that of the substitution of the bridging halogen. The role of the counterion on the mixed-valence state is explained by the hydrogen bond network (Pt–NH···counterion···HN–Pt) on individual chains.
An X-Ray Diffraction Study on the Structure of Solvated Cadmium(II) Ion and Tetrathiocyanatocadmate(II) Complex in N,N-Dimethylformamide
Authors: Ozutsumi Kazuhiko , Takamuku Toshiyuki , Ishiguro Shin-ichi , Ohtaki Hitoshi 
Published: July 2006

Abstract
The structure of solvated cadmium(II) ion and the tetrathiocyanatocadmate(II) complex in N,N-dimethylformamide (DMF) has been determined by means of X-ray diffraction at 25 °C. The radial distribution curve for a cadmium(II) perchlorate DMF solution is well explained in terms of the presence of the octahedral [Cd(dmf)6]2+ complex with the Cd–O bond length of 229.6(4) pm, which is practically the same as that within [Cd(dmso)6]2+ in DMSO and [Cd(H2O)6]2+ in H2O. It is also found that the tetrathiocyanatocadmate(II) complex has a tetrahedral structure, [Cd(NCS)3(SCN)]2−, with three Cd–N and one Cd–S bonds, the distances being 223(2) and 257(2) pm, respectively. The coordination structure of the complex in DMF is different from that found in aqueous solution, [Cd(NCS)2(SCN)2]2−.
Polymer Reagents Derived from Sodium p-Styrenesulfonate: N-Methyl-N-nitroso-p-styrenesulfonamide and p-Styrenesulfinic Acid Polymers
Authors: Kamogawa Hiroyoshi , Kitamura Tomoo 
Published: July 2006

Abstract
N-Methyl-N-nitroso-p-styrenesulfonamide (1) was synthesized starting with sodium p-styrenesulfonate (3). Monomer 1 and sodium p-styrenesulfinate (2), also synthesized starting with 3, were polymerized and polymer of 2 was converted to corresponding free acid (9). The function of polymer of 1 as the reagent attaching the CH2 group to the carbonyl carbon by insertion and that of polymer 9 as the catalyst for cis→trans isomerization were investigated for various compounds, including cyclohexanone and benzaldehyde and ethyl oleate. The effects of these polymer reagents as compared with those of the corresponding model compounds were discussed.
The Preparation of Poly(3-methoxy-2,5-thiophenediyl) with Iron(III) Chloride and Its Properties
Authors: Tanaka Susumu , Kaeriyama Kyoji 
Published: July 2006

Abstract
Soluble and conductive poly(3-methoxy-2,5-thiophenediyl) was obtained by the chemical oxidation of 3-methoxythiophene with iron(III) chloride. The resulting polymer was found to be in a doped state, since it contained 0.1–0.2 counterions (FeCl4− and Cl−) per monomeric unit. This means that the oxidation is a convenient method for preparing conductive polymers in one step. We also obtained a poly-MOT solution and film in a state doped to a great extent, showing no π–π* transition band and a high stability in air. An undoped polymer film was prepared by the electrochemical reduction of the doped film. The undoped film had a π–π* transition band at 2.3 eV, indicating that the effective conjugation length of the polymer could be assumed to be the same as that of the poly(3-methoxythiophene) prepared electrochemically.
Reactions of Sodium Salts of Tosylhydrazones of 2- and 3-Thiophenecarbaldehydes, 1-Methyl-2-pyrrolecarbaldehyde, and Furfural with Acrylonitrile
Authors: Saito Katsuhiro , Sato Tatsuji , Ishihara Hiraku , Takahashi Kensuke 
Published: July 2006

Abstract
Reactions of the sodium salts of tosylhydrazones of several heteroaromatic aldehydes with an equimolar amount of acrylonitrile afforded the corresponding cyclopropane derivatives as the major products accompanied by small amounts of pyrazole derivatives. On the other hand, reactions using ten-molar equivalents of acrylonitrile gave pyrazole derivatives as major products.
Molecular Structures of Diarylcyclobutanes Associated with Reactivities in Ring-Cleavage Reactions: Implications of Conformationally Controlled Through-Bond Coupling
Authors: Shima Kensuke , Kimura Jun , Yoshida Kouhei , Yasuda Masahide , Imada Kiyohisa , Pac Chyongjin 
Published: July 2006

Abstract
Molecular structures of diarylcyclobutanes (1–6) have been determined by single-crystal X-ray analyses. Although the distances and angles of the cyclobutane rings are relatively normal, the torsional angles between the aryl ring and the plane involving the ipso carbon and the aryl-substituted carbons of cyclobutane ring are close to 90° in cases of 1–4, but very small (2.3–11.3°) in cases of 5 and 6; conformations of the aryl substituents are highly restricted by the rigid tricyclic structure or by nonbonding interactions between the vicinal substituents in the cis configuration. Restricted conformations are closely related to the different reactivities of the cyclobutane in photochemical, thermal, and radiation-induced ring-splitting reactions. The structure-reactivity relationships are discussed in terms of the conformation-controlled π–σ orbital interactions associated with the capabilities of the π electron systems in through-bond coupling.
Photochemical Reactions of Aromatic Compounds. XLVI. Stereochemical Reaction Courses in the Photolytic Ring-Cleavage Reactions of Diarylcyclobutanes: Implications of Conformation-Controlled Orbital Interactions in the Excited-State Chemistry
Authors: Pac Chyongjin , Go-an Kazuyoshi , Yanagida Shozo 
Published: July 2006

Abstract
The photolyses of cis-transoid-cis-cyclobutadiindene (1), cis-2-phenylcyclobut[a]indene (2), cis-1,2-diphenylcyclobutane (3), the trans isomer (4), and its dimethyl (5) and tetramethyl (6) derivatives have been investigated to explore stereoelectronic factors controlling the excited-state reaction courses for the ring cleavages. The symmetric ring cleavage occurs regiospecifically in the cases of 1–3 and with 98% specificity in the case of 4. The photolysis of 5 results in both the symmetric and the asymmetric cleavages in a ca. 1 : 3 ratio accompanied by substantial losses of stereointegrity in the olefin formation, and the regiospecific asymmetric cleavage occurs in the case of sterically more congested 6. The ring-cleavage efficiencies systematically decrease in the order 1&gt;2&gt;3&gt;4&gt;5&gt;6 and reveal negative temperature dependences, particularly in the cases of 1, 5, and 6. The features of the reactions are in parallel with stable conformations and conformational mobilities of the aryl groups associated with different π–σ orbital interactions, while the spectroscopic properties of the cyclobutanes are essentially identical with those of benzene chromophores with little electronic perturbation. The photolytic ring-cleavage reactions are discussed in terms of crossing from the localized 1π,π* state to a σ* hypersurface, in which conformation-controlled orbital interactions play important roles. The final products are formed via a pericyclic minimum which might be biradicaloid in nature.
Design and Synthesis of Macromonocyclic Polyamines Composed of Natural Methylene Arrays
Authors: Iwata Masaaki , Kuzuhara Hiroyoshi 
Published: July 2006

Abstract
A general synthetic method applicable to acyclic and cyclic polyamines was developed. The methodology was exemplified by systematical synthesis of twelve macromonocyclic polyamines, 1 ([17]N4) through 12 ([35]N8), composed of the combination of four natural polyamine segments, spermidine, spermine, thermine, and thermospermine. These twelve designed macrocycles are exhausted numbers of possible structures defined by three arbitrarily chosen criteria concerning with methylene chain arrays and nitrogen content (four to eight). The common elements of the structural characteristics were analyzed and were found to be reduced to readily available three classes of simple N,N′-ditosylalkanediamines derived from diamines and triamine. Nitrogen content was increased systematically through the reaction of N,N′-ditosylalkanediamine with one of three ω-phthalimidated electrophiles followed by regeneration of the same functionality at symmetrical both terminals as the starting materials via a series of transformation reaction, in excellent yields. Tractable formamide intermediate profits the facile synthesis of acyclic polyamines with long chains. Cyclization was achieved, under high dilution conditions, through the reaction of α,ω-bis(tosylamide) with α,ω-ditosylates in DMF in the presence of cesium carbonate. The cyclization occurred in practical synthetic yields even in the formation of multi-membered ring when the shorter electrophile and the longest α,ω-bis(tosylamide) reacted.
Synthesis of S-Methyl 2-Hydroxyalkanethioates, 2-Hydroxyalkanoic Acids and Related Compounds via the Addition Reaction of Tris(methylthio)methanide Ion to Alkanals
Authors: Orito Kazuhiko , Seki Yoshikatsu , Suginome Hiroshi , Iwadare Tsukasa 
Published: July 2006

Abstract
In connection with the studies on biological activities on myrmicacin and related compounds, the synthetic method for 2-hydroxyalkanoic acids and the corresponding 1,2-diols was studied. The addition reaction of tris(methylthio)methyllithium to the aldehydes (propanal–dodecanal) gave the corresponding 1,1,1-tris(methylthio)-2-alkanols 1a–j. Treatment of 1 with mercury(II) chloride–mercury(II) oxide in water–acetone afforded S-methyl 2-hydroxyalkanethioates 2a–j, and in methanol methyl 2-hydroxyalkanoates 3c–j were obtained. Reduction of the thioates 2 with lithium aluminium hydride gave 1,2-diols 4c–j and saponification produced the corresponding 2-hydroxyalkanoic acids 5c–j.
Deuterium Isotope Effect on the Rate of Ligand Exchange between Tetrakis(acetylacetonato)thorium(IV) and Free Acetylacetone in CD3CN
Authors: Fujiwara Naoshi , Nakagawa Tomoe , Tomiyasu Hiroshi , Fukutomi Hiroshi 
Published: July 2006

Abstract
A deuterium isotope effect on the rate of acetylacetonate exchange between tetrakis(acetylacetonato)thorium(IV), Th(acac)4, and free acetylacetone in CD3CN has been examined by means of 1H NMR technique. The second-order rate constant, k, which is expressed as a function of the observed first-order rate constant, kobsd, and the concentration of acetylacetone in the enol form, [acetylacetone]enol, by k=kobsd/[acetylacetone]enol was determined for the reaction of deuterated acetylacetone, Dacac, as well as undeuterated acetylacetone, Hacac. The ratio of second-order rate constants for Hacac and Dacac, kH⁄kD, was approximately 9. This large deuterium isotope effect strongly supports a mechanism proposed in a previous paper that the proton transfer process is the rate determining step of the whole reaction.
Indirect Electrooxidation by Using Ruthenium Tetraoxide and Chloride Ion as Recycling Mediators. Optimization for the Oxidation of Diisopropylidene-d-glucose to the Ulose
Authors: Torii Sigeru , Inokuchi Tsutomu , Matsumoto Shigeaki , Saeki Takeaki , Oki Tsunehei 
Published: July 2006

Abstract
Various factors related to the yield and selectivity for the indirect electrooxidation of diisopropylidene glucose (1) to the ulose 2 with ruthenium tetraoxide (RuO4) and chloride ion are investigated. The following is found to be optimum conditions: pH, ca. 10: solvent system, carbon tetrachloride and t-butyl alcohol (ca. 9 : 1); current density, 10–40 mA cm−2; temperature, 20–40 °C; catalyst amount, 2 mol% of RuO2·2H2O (based on 1). The optimized electrolysis affords the desired 2 in 90% yield along with a trace of the cleavaged product 3 (0.2%) by an overoxidation.
Tellurodicarbonic Acid Diesters; Preparation and Properties
Authors: Suzuki Hitomi , Nishioka Yoshinobu 
Published: July 2006

Abstract
Title compounds were obtained as reasonably stable to labile oily substances by reacting alkyl carbonochloridates with sodium telluride under phase-transfer conditions at room temperature or in dry N,N-dimethylformamide under ice-cooling.
Silica-Supported Heteropoly Acid Catalyst for Liquid-Phase Friedel–Crafts Reactions
Authors: Izumi Yusuke , Natsume Noriko , Takamine Harumi , Tamaoki Ikuyo , Urabe Kazuo 
Published: July 2006

Abstract
Silica-supported Keggin-type heteropoly acids such as 12-tungstophosphoric, molybdophosphoric, and tungstosilicic acids efficiently catalyzed Friedel–Crafts alkylation and acylation reactions of aromatic hydrocarbons with 1-octene, benzyl chloride and benzoyl chloride in the liquid phase. The catalytic activity of heteropoly acid was generally enhanced when supported on silica. Silica-supported tungstosilicic acid worked as an insoluble heterogeneous catalyst even to the acylation of p-xylene with benzoyl chloride or benzoic anhydride, though deactivation was observed during repeated use. Considering that supported p-toluenesulfonic acid, an ordinarily used typical strong protonic acid, was far less active than the supported heteropoly acid, the high catalytic efficiency revealed by heteropoly acid appears to be due to a unique property of heteropoly anion which can stabilize alkyl and acyl cations as the reaction intermediates.
Ionic Association of Mixed Nickel(II) Chelates in Alcohols, Ketones, and Nitrobenzene
Authors: Ito Kazuaki , Yamamoto Yuroku 
Published: July 2006

Abstract
The conductances of mixed nickel(II) chelates, [Ni(acac)(N,N,N′,N′-tmen)]X (where acac=2,4-pentanedionato, N,N,N′,N′-tmen=N,N,N′,N′-tetramethylethylenediamine, and X−=ClO4− or NO3−), in alcohols {ethanol (EtOH), 1-propanol (n-PrOH), 2-propanol (i-PrOH), and 1-butanol (n-BuOH)}, ketones {acetone (Me2CO), methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK)}, and nitrobenzene (PhNO2) were measured at 25 °C. The obtained ionic association constants (Ka) of [Ni(acac)(N,N,N′,N′-tmen)]ClO4 which were derived by using the extended Fouss–Hsia function indicated that (1) the perchlorate complex is a normal type of uni-uni-valent electrolyte and (2) it is more dissociated than [Co(acac)2(N,N,N′,N′-tmen)]ClO4 in EtOH, n-PrOH, and n-BuOH. Walden products of the cations suggest that the nickel(II) chelate cation in the alcohols is present as an octahedral form with the coordination of two solvent molecules. On the other hand, Ka of [Ni(acac)(N,N,N′,N′-tmen)]NO3 are much larger than those of [Ni(acac)(N,N,N′,N′-tmen)]ClO4. This can be ascribed to the coordination of a nitrate ion to the nickel(II) ion. The effect is large and approximately the same in the ketones and PhNO2, though small in EtOH, n-PrOH, and n-BuOH due to the coordination of solvent molecules.