bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Electrolyte Effect on the Chemical Equilibria of Bis(β-diketonato)nickel(II) Complexes in Dimethyl Sulfoxide
Authors: Kudo Setsuko , Iwase Akio 
Published: July 2006

Abstract
The electrolyte effect on the homogeneous chemical equilibria of Ni(bfac)2, Ni(ftac)2, and Ni(ttac)2 in dimethyl sulfoxide has been studied by means of polarographic and ultraviolet spectral measurements, where bfac−, ftac−, and ttac− represent the enolate anions of benzoyltrifluoroacetone, 2-furoyltrifluoroacetone, and 2-thenoyltrifluoroacetone respectively. The chemical equilibria of these complexes in 0.05 mol dm−3 TBAP solutions found previously:
Ni(bi-L)2\ightleftharpoonsNi(bi-L)(uni-L)\ightleftharpoonsNi(bi-L)++L−\ightleftharpoonsNi(uni-L)++L−
shifted more to the right in the presence of one of the electrolytes (NaClO4, KClO4, RbClO4, CsClO4, TMAP, or TEAP) at the same concentrations as TBAP; bi- and uni- mean that the ligands coordinate to the metal as bidentate and unidentate respectively. Under the conditions of [NiL2]=1 mmol dm−3 and [MClO4]=0.05 mol dm−3, the molar fractions of the species of the Ni(bi-L)2 type decreased with an increase in the inverse of the cationic radii. Such a tendency was explained mainly in terms of the interaction between the π-electron system of Ni(bi-L)2 and those cations. For the same metal perchlorates, except NaClO4, the stability of Ni(bi-L)2 decreased in the order of: bfac−&gt;ftac−&gt;ttac−.
Double Diels-Alder Reaction of trans-3-Methylene-1,4-hexadiene and 1-Methyl-3-methylene-4-pentenyl Tosylate
Authors: Kanemasa Shuji , Sakoh Hirohiko , Wada Eiji , Tsuge Otohiko 
Published: July 2006

Abstract
A cross-conjugated triene, trans-3-methylene-1,4-hexadiene, is accessible from the Grignard reagent of chloroprene and methyloxirane via 1-methyl-3-methylene-4-pentenyl tosylate. The diene-transmissive Diels–Alder reaction of the triene and the stepwise sequence of double Diels–Alder reaction of the tosylate are investigated. Stereo- and regioselectivity of these reactions in the presence or absence of Lewis acid catalyst are discussed.
Kinetics and Mechanism of the Oxidative Deamination of Amines by Coenzyme PQQ
Authors: Itoh Shinobu , Kitamura Yutaka , Ohshiro Yoshiki , Agawa Toshio 
Published: July 2006

Abstract
Kinetic studies on the oxidative deamination of amines by coenzyme PQQ are carried out under anaerobic conditions. The reaction is first-order in the appearance of the reduced PQQ and in the total amine concentrations. A large kinetic isotope effect (kH⁄kD=7.24) in the oxidation of α,α-dideuteriobenzylamine indicates that the C–H bond cleavage is a rate-determining step. From the results of formation of two types of reduced PQQ (quinol and aminophenol) and low reactivities of secondary and tertiary amines, we propose the mechanism via covalent addition of the amine to the quinone followed by rate-limiting α-proton removal.
Vapor-Phase Isomerization of o-Chlorotoluene over H-Mordenite Treated with CF3Cl
Authors: Okazaki Susumu , Jouhouji Hirofumi 
Published: July 2006

Abstract
Vapor phase-isomerization of o-chlorotoluene was somewhat promoted by H-mordenite (HM). The catalytic activity was appreciably enhanced by treatment with CF3Cl and other chlorofluorocarbons such as CF2ClCF2Cl and CF2ClCF3. In particular, maintenance of the HM catalyst activity was remarkably improved by CF3Cl treatment. The CF3Cl-treated HM also promoted vapor phase isomerizations of p- and m-chlorotoluene. The catalytic activity was relatively long-lasting for the isomerization of p-chlorotoluene. Enlargement of the HM pore size on treatment with CF3Cl and other chlorofluorocarbons may contribute to increasing the catalytic activity and then maintaing it.
Analysis of Proton-Transfer Reaction in Aqueous Solutions of Butylamines by Ultrasonic Methods
Authors: Yoshida Yukio , Nishikawa Sadakatsu 
Published: July 2006

Abstract
Ultrasonic absorption has been measured in an aqueous solution of s-butylamine over the frequency range 6.5–220 MHz and the concentration range 0.0115–3.18 mol dm−3 at 25 °C. The single relaxational phenomenon observed in a range less than 1 mol dm−3 was found to be associated with a perturbation of the equilibrium; R-NH3++OH− (Remark: Graphics omitted.) R-NH3+···OH−. The rate constants of the forward and backward reactions, k12 and k21, have been determined to be 2.1×1010 s−1 mol−1 dm−3 and 1.8×108 s−1, respectively. It was also determined that the next step, R-NH3+···OH− (Remark: Graphics omitted.) R-NH2+H2O, which had been thought to have a considerable influence on the first step, was not very effective regarding the ultrasonic absorption observed in the MHz frequency range. The equilibrium constant in the second step, K32, has been determined to be 3.5×10−2. The standard volume change of the reaction has been calculated to be 26 cm3 mol−1 from the concentration dependence of the maximum excess absorption per wavelength. The relaxation observed in a range greater that 1 mol dm−3 has been estimted to be associated with a molecular aggregation reaction. An ultrasonic study in an aqueous solution of butylamine has also been performed in order to determine the rate constants associated with a proton-transfer reaction at 25 °C.
Chemical Effectiveness of Elastic and Inelastic Energy Loss of He+, Ar+, and Xe+ Ions Bombarding Solid Potassium Nitrate
Authors: Ohno Shin-ichi , Furukawa Katsutoshi , Soga Takeshi 
Published: July 2006

Abstract
Decomposition of crystalline potassium nitrate due to He+-, Ar+-, and Xe+- ion bombardment was studied in the energy range from 20 to 100keV. The cross sections for producing nitrite ions were for the first time determined to be 5.7×10−20m2, 12.6×10−20, and 22.0×10−20m2 for 100keV He+, Ar+, and Xe+ ion, respectively. Comparing the values of these cross sections with the rate of an elastic and inelastic energy loss of these incident ions, which were calculated on the basis of the theory of Lindhard et al., it may be concluded that inelastic energy is about five times more efficient than elastic energy for the decomposition of the solid potassium nitrate.
Benzo-15-crown-5 Linked Spirobenzopyran. I. Photocontrol of Cation-Binding Ability and Photoinduced Membrane Potential Changes
Authors: Sasaki Hiroshi , Ueno Akihiko , Anzai Jun-ichi , Osa Tetsuo 
Published: July 2006

Abstract
Benzocrown ether-linked spirobenzopyran (1) and its analogue (2) which has no crown ring were synthesized. The binding abilities of 1 for alkali metal cations (Na+, K+, Rb+, Cs+) were found to change by UV light irradiation, while 2 did not bind these cations before and after UV light irradiation. The plasticized poly(vinyl chloride) (PVC) membrane entrapping 1 or 2 showed photoinduced potential changes reversibly by UV and visible light irradiation. In the membranes of both 1 and 2 showed normal photochromism of spirobenzopyran. In the case of 1, the magnitude of the photoinduced potential change depended upon kind and concentration of alkali metal cations. However, the magnitude of photoinduced potential change of the membrane entrapping 2 was hardly affected by kind and concentration of alkali metal cations. The results are explained in terms of cooperative action of both crown ether and spiropyran.
Hydrogen Atom Transfer Reaction through Partial Charge-Transfer Triplet Complex. Chloranil and Mesitylene System
Authors: Kobashi Harumichi , Okada Tadashi , Mataga Noboru 
Published: July 2006

Abstract
Mechanism and kinetics of hydrogen atom transfer reaction from mesitylene (M) to triplet chloranil (3CA) in 1,2-dichloroethane (DCE) at room temperature have been studied by means of picosecond (ps) and nanosecond (ns) laser flash photolysis techniques. It was found that the hydrogen transfer resulting in the formation of chloranil semiquinone radical (CAH·) proceeded through a partial charge-transfer (CT) triplet complex between 3CA and M as an intermediate. No ion-pair formation was observed. The triplet complex showed transient absorption bands in the visible and near infrared regions. The association constant (KT=28 dm3 mol−1) and lifetime (τC=32 ns) of the complex were estimated from a kinetic analysis for 3CA quenching. From these results, combined with those of the quantum yield of CAH· formation, the first order rate constants for the hydrogen transfer and intersystem crossing in the triplet complex were estimated to be (1.7 and 1.4)×107 s−1, respectively.
The Synthesis of 3-Aryl-5-dialkylamino-1,4,2-dithiazol-1-ium Salts
Authors: Shibuya Isao , Yonemoto Katsumi 
Published: July 2006

Abstract
N-(Dialkylthiocarbamoylthio)arenecarboxamides, prepared by acylation of the corresponding S-dialkylthiocarbamoyl-substituted sulfenamides, cyclized with dehydration in a strong acidic media to form a number of 3-aryl-5-dialkylamino-1,4,2-dithiazol-1-ium salts in good yields.
Biomimetic Application of Natural Valinomycin and Nonactine Ionophores to Artificial Transport of Amino Acid Salts
Authors: Tsukube Hiroshi , Takagi Kentaro , Higashiyama Tatsuo , Iwachido Tadashi , Hayama Naomi 
Published: July 2006

Abstract
Biological valinomycin and nonactine ionophores showed new and interesting transport abilities for important amino acid salts in the biomimetic membrane systems, which are of biological interest and of practical significance.
Complex Formation between Heptylviologen and Cyclodextrin
Authors: Kodaka Masato , Fukaya Toshio 
Published: July 2006

Abstract
Complex formation between heptylviologen (1) and cyclodextrins (α and β) was confirmed indirectly. The absorption and circular dichroism (CD) spectra of p-nitrophenolate aqueous solution containing α- or β-cyclodextrin were changed, when 1 was added to the solution. Contrary to 1, methylviologen (3) did not give the spectral changes.
Cyclic Peptides. XXII. Synthesis of [2-Amino-2,3-dehydrobutanoic Acid4]AM-Toxin I
Authors: Mihara Hisakazu , Aoyagi Haruhiko , Ueno Tamio , Kato Tetsuo , Izumiya Nobuo 
Published: July 2006

Abstract
To investigate the role of the side chain of the 2,3-dehydroalanine (ΔAla) residue at position 4 in a cyclic tetradepsipeptide phytotoxin AM-toxin I on necrotic activity for apple leaf, [2-amino-2,3-dehydrobutanoic acid4] AM-toxin I was synthesized by two different routes. This analog showed no toxic activity, indicating that the side chain of the ΔAla residue can not be handled without loss of the activity.
Practical Synthesis of 1,1′-Binaphthyl-2-carboxylic Acids via Side Chain Oxidation of 2-Methyl-1,1′-binaphthyls
Authors: Miyano Sotaro , Okada Shin-ichi , Suzuki Toshiyuki , Handa Shigeru , Hashimoto Harukichi 
Published: July 2006

Abstract
Four 1,1′-binaphthyl-2-carboxylic acids were obtained in 38–53% isolated yield via three-stage oxidation of 2-methyl-1,1′-binaphthyls, that is, i) NBS-bromination to benzylic bromides, ii) treatment with sodium salt of 2-nitropropane to aldehydes, and iii) KMnO4–oxidation to carboxylic acids.
A Convenient Synthesis of (±)-Dimorphecolic Acid and Its Analogs
Authors: Tsuboi Sadao , Maeda Seiji , Takeda Akira 
Published: July 2006

Abstract
Dimorphecolic acid, self-defensive substances in rice plant against rice blast disease, and its analogs were prepared stereoselectively by the reaction of (2E,4Z)-2,4-decadienal with Grignard reagents.
The Formation Process of Hydrous Gallium(III) Oxide Particles Obtained by Hydrolysis at Elevated Temperatures
Authors: Hamada Shuichi , Bando Koji , Kudo Yoshiyuki 
Published: July 2006

Abstract
Hydrous gallium(III) oxide was produced as monodispersed spherical particles by forced hydrolysis in the presence of sulfate ions, though they partially dissolved and recrystallized. The rate of the reaction degree was empirically expressed under the given conditions as dα⁄dt=1.60α2⁄3(1−α)0.874, where α is the reaction degree. Polymeric hydroxo complexes were confirmed to act as precursors of the monodispersed spherical particles, judging from the fractional changes of the monomeric and polymeric species during the hydrolysis. The role of sulfate ions in the formation of hydrous gallium(III) oxide particles was discussed.
Three-Dimensionally-Modified Tetracyanoquinodimethanes and Their Charge-Transfer Complexes with Tetrathiafulvalene Derivatives Having a Wide Range of Ionicity
Authors: Nakasuji Kazuhiro , Nakatsuka Masakatsu , Yamochi Hideki , Murata Ichiro , Harada Shigeharu , Kasai Nobutami , Yamamura Kimiaki , Tanaka Jiro , Saito Gunzi , Enoki Toshiaki , Inokuchi Hiroo 
Published: July 2006

Abstract
Eight different 1:1 charge-transfer(CT) complexes were prepared using tetrahydrobarreleno-tetracyanoquinodimethane(THBTCNQ), dihydrobarreleno-tetracyanoquinodimethane(DHBTCNQ), monobenzobarreleno-tetracyanoquinodimethane(MBBTCNQ), and dibenzobarreleno-tetracyanoquinodimethane(DBBTCNQ) as tetracyanoquinodimethane(TCNQ)-type acceptors, and tetrathiafulvalene(TTF), bis(tetramethyene)-tetrathiafulvalene(OMTTF), and tetramethyl-tetrathiafulvalene(TMTTF) as TTF-type donors. The complexes can be classified into three distinct groups, I–III, on the basis of the magnitude of both the degree of CT and the electrical resistivity of compacted powders. Group-I complexes are characterized by a small band gap semiconductivity and moderate CT, group-II complexes by low conductivity and small CT, and group III complexes by low conductivity and complete CT. The stacking mode of the three groups of complexes are discussed, by comparing the electronic absorption spectra of the three groups of CT complexes with those of the complexes for which the crystal structures are known. A crystal structure analysis of OMTTF–DBBTCNQ revealed that it is the first example of a highly ionic CT complex of a TTF–TCNQ type with a regular mixed stacking mode. These three groups of complexes containing bulky acceptor groups will be of theoretical interest in studying the crystal properties of organic CT complexes.
Mössbauer Spectroscopic Studies of Mercury(II) Chloride Adducts with Binuclear Metallocenes
Authors: Watanabe Masanobu , Motoyama Izumi , Sano Hirotoshi 
Published: July 2006

Abstract
Biferrocene and ferrocenylruthenocene react with HgCl2 to give very stable adducts. Large quadrupole splitting values (2.93 mm s−1 for biferrocene–2HgCl2 and 2.99 mm s−1 for ferrocenylruthenocene–5HgCl2, both at 78 K) indicate the presence of a direct interaction between the Fe and Hg atoms. The stabilities of their adducts suggest a chelating effect between the Fe and Fe or Fe and Ru atoms in biferrocene or ferrocenylruthenocene, respectively.
The Syntheses, Properties, and Crystal and Molecular Structures of the Lanthanoid Mixed-Complexes of O,O′-Diisopropyl Dithiophosphate and Dimethyl Sulfoxide: [Ln{(C3H7O)2PS2}3{(CH3)2SO}2] (Ln=La or Nd), and [Eu{(C3H7O)2PS2}2{(CH3)2SO}3][Eu{(C3H7O)2PS2}4]
Authors: Imai Takashi , Nakamura Masao , Nagai Kiyofumi , Ohki Yoshiyuki , Suzuki Yasuo , Shimoi Mamoru , Ouchi Akira 
Published: July 2006

Abstract
Two types of the mixed complexes indicated in the title have been synthesized, and their crystal and molecular structures of the lanthanum (1) and the europium (2) complexes have been determined by the X-ray diffraction method. Both 1 and 2 are monoclinic, space group P21⁄n, and Z=4. 1, a=17.354(7), b=23.336(4), c=10.955(2) Å, β=96.04(2)°, final R value calculated from 4870 reflections is 0.069; 2, a=29.846(7), b=20.070(3), c=14.057(3) Å, β=92.13(2)°, final R value calculated from 7811 reflections is 0.077. In 1, the central metal atom is octa-coordinated, and is in a dodecahedral geometry, where all O,O′-diisopropyl dithiophosphato ligands (iPr2dtp) span m-edges of the dodecahedron, chelating through both of the respective sulfur atoms. Dimethyl sulfoxide (dmso) ligands occupy the apexes of the other m-edge. In 2, the europium(III) metal atom of the cationic species is hepta-coordinated and is in a pentagonal-bipyramidal geometry where two oxygen atoms of dmso ligate from respective ends of the axis and one oxygen atom of the remaining dmso from the equatorial direction. The central metal atom of the anion is octa-coordinated and is in a dodecahedron; where all m-edges are spanned by iPr2dtp ligands. The solid and the acetonitrile solution of 2 is orange in color due to the charge-transfer band (λmax=415 nm; εmax=1.5×102 dm3 mol(Eu)−1 cm−1).
Isomerism of the Metal Complexes Containing Multidentate Ligands. X. [CoN6]3+-Type Complexes Containing H2N(CH2CH2NH)nH (n=0–4)
Authors: Yoshikawa Yuzo , Kato Nobuyuki , Kimura Yuito , Utsuno Shunji , Natu Gopal N 
Published: July 2006

Abstract
The preparation, separation, and characterization of isomeric complexes of type [CoN6]3+, containing one, two, or three molecules of NH3, en, dien, trien, and tetren (n=0, 1, 2, 3, and 4, respectively for H2N(CH2CH2NH)nH) are reported. All the possible five stereoisomers for [Co(NH3)(en)(dien)]3+ and six stereoisomers for [Co(en)(trien)]3+ have been successfully isolated, but only three of four possible geometrical isomers could be obtained for [Co(NH3)(tetren)]3+. These were characterized by electronic, circular dichroism (CD), and 13C{1H} NMR spectroscopy. Conformational analyses were, also, carried out and the stability, or formation of each isomer at the equilibrium state, is discussed from the calculated strain-energy data and experimental formation ratios.
Organopalladium(II) Complexes Containing Carbon-Bonded Heterocycles as a Ligand
Authors: Isobe Kiyoshi , Nanjo Kazuharu , Nakamura Yukio , Kawaguchi Shinichi 
Published: July 2006

Abstract
Oxidative addition reactions of 2-chloropyridine, 2,6-dichloropyridine, 2-chloropyrazine, and 2-chlorobenzothiazole with tetrakis(triphenylphosphine)palladium(0) gave [{PdCl(R)(PPh3)}2] or trans-[PdCl(R)(PPh3)2] depending on the nature of the carbon-bonded heterocycles R. They are all stable and the chloride ligand is readily replaced by other halides and pseudohalides. These novel organopalladium(II) complexes were characterized by the analytical and molecular-weight data together with IR, 1H NMR and 13C NMR spectra, and the 2-pyridyl-bridged dinuclear structure of [{PdBr(C5H4N-C2)(PPh3)}2] was previously revealed by X-ray analysis. Both of the dinuclear and mononuclear 6-chloro-2-pyridylpalladium(II) complexes catalyze the cross coupling reaction between 2,6-dichloropyridine and methylmagnesium bromide to afford 2-methyl-6-chloropyridine selectively. The mononuclear 6-chloro-2-pyridylpalladium(II) complexes react with carbon monoxide to form the acyl complexes.
Perfluoropropylation of Furans, Thiophenes, and Pyridines with Bis(heptafluorobutyryl) Peroxide
Authors: Sawada Hideo , Yoshida Masato , Hagii Hidehiko , Aoshima Kazuyoshi , Kobayashi Michio 
Published: July 2006

Abstract
Bis(heptafluorobutyryl) peroxide (1) smoothly reacted with furans and thiophenes under mild conditions to regioselectively give 2-perfluoropropylfurans and thiophenes in high yields. Mechanistically, reactions with furans or thiophenes are considered to be initiated by one-electron transfers from substrates to 1. On the other hand, the perfluoropropylation of pyridine was proceeded by the usual free-radical substitution to a pyridinium salt by a heptafluoropropyl radical produced by the homolytic decomposition of 1.
13C and 1H NMR of α-Arylnitrones. Substituent Effects on the α-Position of α-(p-Substituted Phenyl)nitrones
Authors: Yijima Chino , Tsujimoto Toshio , Suda Kohji , Yamauchi Masashige 
Published: July 2006

Abstract
Substituent effects on the 13C and 1H NMR chemical shifts of the α-position of various α-(p-substituted phenyl)nitrones, α-phenyl-N-(1-cyano-2-methylpropyl)nitrones (1), α-phenyl-N-methylnitrones (2), and α-phenyl-N-phenylnitrones (3), have been investigated and the obtained results have been compared with data related to N-(p-substituted benzylidene)anilines (4) and reported data for p-substituted styrenes (5). The chemical shifts of the α-arylnitrones are well correlated with substituent constants by means of a linear combination of two empirical parameters, σi and σπ. Inductive effects predominate at the α-carbon but resonance effects predominate at the α-hydrogen.
X-Ray Photoelectron Spectroscopy of Rare Earth Halides
Authors: Uwamino Yoshinori , Tsuge Akira , Ishizuka Toshio , Yamatera Hideo 
Published: July 2006

Abstract
Rare earth (RE) halides (fluorides, chlorides, bromides, and iodides) have been studied by X-ray photoelectron spectroscopy. The binding energies (BE’s) of the RE 3d and 4d peaks for the chlorides, bromides, and iodides are related to the atomic charge calculated on the basis of Pauling’s scale of electronegativity (Pauling charge). Except for Y and Lu, the observed RE 3d and 4d BE’s for the fluorides are lower than those expected. For Y and Lu, the observed RE 3d and 4d BE’s for all halides are related to the Pauling charge. For the fluorides and chlorides, the BE’s of the ligand peak show variations with increasing atomic number of RE’s and a specific “tetrad effect” is observed in plots of BE versus RE atomic number and versus 1/R (where R is the mean distance from the ligand atom to the neighboring RE atom), except for the BE’s of the F 1s peaks from the light RE fluorides. For the iodides and bromides, no or little characteristic variations are seen in the BE’s of I and Br.
Catalytic Action of Iron and Manganese Ions in the Photochemically-Induced Oxidation of d-Fructose with Atmospheric Oxygen
Authors: Araki Koji , Shiraishi Shinsaku 
Published: July 2006

Abstract
d-Fructose is susceptible to photochemically-induced oxidation by atmospheric oxygen in the presence of a catalytic amount of iron or manganese cations in a neutral to weakly basic pH range. Metal hydroxide does not precipitate from a solution in this pH range because of the high sequestering ability of d-fructose. Upon irradiation of Pyrex-filtered light, d-fructose degraded into d-erythrose and other fragments. This reaction is shown to proceed by coupling with an oxidation-reduction cycle involving a metal cation, i.e., the photooxidation of d-fructose by M(III) and the subsequent reoxidation of the resultant M(II) by atmospheric oxygen.
Kinetics and Mechanism of the Extraction of Nickel(II) with 3-Mercapto-1,5-Diphenylformazan in the Presence of 1,10-Phenanthroline or Pyridine
Authors: Ohashi Kousaburo , Shoji Hidetoshi , Yamamoto Katsumi 
Published: July 2006

Abstract
The kinetics and mechanism of the extraction of nickel(II) with 3-mercapto-1,5-diphenylformazan (dithizone, Hdz) into chloroform in the presence of 1,10-phenanthroline (phen) or pyridine (py) were studied in the presence of 0.1 mol dm−3 or 0.2 mol dm−3 NaNO3 at 25 °C. For the nickel(II)–dithizone–1,10-phenanthroline system, the rate-determining steps were the competitive reactions of nickel(II) with dithizonate and with 1,10-phenanthroline in an aqueous phase. The second-order rate constants for the formation of [Ni(dz)]+ and of [Ni(phen)]2+ were determined to be (6.0±0.4)×103 mol−1 dm3 s−1 and (3.4±0.2)×103 mol−1 dm3 s−1 respectively. It was suggested that [Ni(phen)]2+ is more reactive toward dithizonate than toward 1,10-phenanthroline in an aqueous phase. The formation of [Ni(phen)2]2+ retards the extraction of nickel(II) with dithizone. For the nickel(II)–dithizone–pyridine system, the rate-determining step is probably the reaction of [Ni(py)]2+ with dithizonate in an aqueous phase. The second-order rate constant for this reaction was determined to be (1.7±0.3)×105 mol−1 dm3s−1.