bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous Formation of a Polypyrrole Film and a Tantalum Oxide Layer by Electrochemical Oxidation
Authors: Park Young-seo , Yamamoto Kimihisa , Takeoka Shinji , Tsuchida Eishun
Published: July 2006

Electropolymerization of pyrrole on tantalum (Ta) electrodes was carried out in Britton-Robinson buffer solutions containing 0.1 M (1 M = 1 mol dm−3) potassium chloride (KCl) under galvanostatic conditions. A polypyrrole (PPy) film and a tantalum oxide (Ta2O5) layer are formed on a Ta electrode by one electrochemical oxidation process. The conditions of this simultaneous formation were investigated in respect with the current density, pyrrole concentration, pH, and total charge. Under certain conditions ([py] = 0.5 M, pH = 1.8, current density = 3.5 mA cm−2, charge 1 C), a 5.6 μm thick PPy film was efficiently formed on a homogeneous 45 nm thick Ta2O5 layer.
Removal of Phosphate from Dilute Phosphate Solution by an Iron Chitosan Complex to Be Used as an Oral Sorbent
Authors: Jing Shi-Bing , Yamaguchi Tatsuaki
Published: July 2006

The long-period administration of aluminum-containing phosphate binders for the treatment of hyperphosphatemia has been shown to carry the risk of aluminum accumulation associated with many bone diseases. An iron chitosan complex prepared by chitosan and iron(II) sulfate was examined as an alternative intestinal phosphate binder. In-vitro experiments have shown that the phosphate-binding capacity of iron chitosan increases with increasing the iron content of iron chitosan, the concentration of phosphate, and the pH of the solution. The phosphate-binding capacity of iron chitosan (iron content 32 mg g−1) was over 30 mg g−1 when 10 mg of iron chitosan was admitted to 10 ml of a phosphate solution of 10 mg dl−1 (pH 7.5) at 37 °C for 6 h. This value is much higher than those of aluminum hydroxide, calcium carbonate, etc., which were practically tried before. No elution of the iron from iron chitosan could be detected under these conditions.
Selective Permeation Properties of Inorganic Ions across a Hydrophobic Membrane
Authors: Igawa Manabu , Nishiura Rie , Mashiyama Noriyuki , Usuda Yoshimi
Published: July 2006

A hydrophobic membrane was prepared from poly(tetrafluoroethylene-co-hexafluoropropylene) by coating method to be a very thin membrane with a high water permeability. The permeation, the diffusion, and the distribution coefficients were measured by time lag method. The permeation coefficient of a salt decreased with the increase of the hydrophilicity of the salt, while hydrophilic salts are permeated readily by the coupling of water flux under a pressure gradient. The characteristic permeation properties of the hydrophobic membrane were caused by the hydrophobic hydration in the pores of the membrane and a hydrophilic ion has a low diffusion coefficient and a high distribution coefficient. The diffusion coefficient of potassium chloride increased with the increases of the temperature or the concentration, while the distribution coefficient had a minimum value at about 55 °C and decreased with the increase of the concentration. Some organics added to the source phase solution affected the hydration structure in the membrane, which changed the permeation properties of salts.
Crystal Structures and Molecular Packing of Tetrakis(alkylthio)tetrathiafulvalene (TTCn–TTF); Part I (n = 3,4,6)
Authors: Nakano Chikako , Mori Takehiko , Imaeda Kenichi , Yasuoka Noritake , Maruyama Yusei , Inokuchi Hiroo , Iwasawa Naoko , Saito Gunzi
Published: July 2006

The crystal structures of tetrakis(alkylthio)tetrathiafulvalene TTCn–TTF (n = 3, 4, 6) were determined by X-ray analysis. The structures of TTCn–TTF drastically changed between n = 3 and 4. The TTC3–TTF molecule has a boat-like shape, like that of TTC1–TTF and TTC2–TTF. On the other hand, the TTC4–TTF and TTC6–TTF molecules have chair-like shapes, like that of TTC5–TTF, and columnar structures with intermolecular effective overlaps between the central π-systems. These results can explain the drastic change in the electrical properties between n = 3 and 4.
Piezoelectric Admittance Measurements of Montmorillonite/Poly(vinyl alcohol) Composite Film-Coated Quartz Crystal Oscillators
Authors: Okajima Takeyoshi , Sakurai Hidetaka , Oyama Noboru , Tokuda Koichi , Ohsaka Takeo
Published: July 2006

The piezoelectric admittance measurements of montmorillonite/poly(vinyl alcohol) (PVA) composite film-coated quartz crystal oscillators were performed in air dried over silica gel, in an atmosphere of moisture with 100% relative humidity at 25 °C and in contact with Na2SO4 aqueous solutions. By use of the electrical equivalent circuit model conventionally proposed for a piezoelectric quartz crystal, the relevant circuit parameters; resistance R, inductance L, and capacitance C were evaluated as a function of the Na2SO4 concentration (0.01–1.0 M (1 M = 1 mol dm−3)). R was almost constant above ca. 0.35 M and increased with decreasing the concentration in the lower concentrations, while L and C were almost independent of the concentration. On the basis of the electrolyte concentration dependence of R, the structural change of the clay/PVA composite film due to swelling with the electrolyte is discussed in comparison with the results for the clay film.
A Magnetic Study of the Iron(III) Complexes of Polyols and Sugars in Aqueous Solution
Authors: Yokoi Hiroshi , Mori Yasuyoshi , Mitani Tsuyoshi , Kawata Satoshi
Published: July 2006

Plots of the effective magnetic moment (μeff) of the iron(III) ion against pH for aqueous iron(III) ion solutions of 1,2-ethanediol, 1,3-propanediol, glycerol, d-glucitol, d-fructose, two oligo-sugars, poly(vinyl alcohol) (PVA), and methyl cellulose at various concentration ratios of polyols or sugars to the iron(III) ion ([iron(III) ion] = 10.0 mM) at room temperature were obtained by the Gouy method. At low concentraion ratios, precipitation resulted at around neutral pH, where the concentration of polymers is expressed in terms of the monomeric residues. The pH range for precipitation became narrower as the ratio increased. However, the precipitates, once formed for the case of the former two diols, remained unchanged at any alkaline pH. During the course of the change in pH from 1 to 13, the μeff value in units of B.M. was initially ca. 6, but steeply decreased at around pH 2, and then leveled off at a constant value of ca. 3.6 in the pH range 3 to 10. It gradually rose to a value of 5–6 beyond pH 10 for the cases of glycerol, d-glucitol, and sugars. This fact, together with the ESR data obtained here, indicates that iron(III) ions exist as usual hydrated ions at pH 1–2, as some cluster like Fe(OH)3 at pH 3–10, and mostly as mononuclear ions coordinated to the alcoholic OH groups at a stronger base pH.
Esterification of Boric Acid with 1,2-Propanediol, 3-Amino-1,2-propanediol, and (±)-3-Dimethylamino-1,2-propanediol as Studied by 11B NMR Spectroscopy
Authors: Oi Takao , Takeda Takuya , Kakihana Hidetake
Published: July 2006

Ester formations of borate ion with 1,2-propanediol, 3-amino-1,2-propanediol, and (±)-3-dimethylamino-1,2-propanediol and stabilities of the formed esters were studied by 11B NMR spectroscopy. For each of the boric acid–diol systems, esters with the 1 : 1 mole ratio of borate ion and diol and with the 1 : 2 mole ratio were formed. In each of the amino–diol–containing systems the 1 : 1 ester was in fact composed of two esters; one from a borate ion and a diol molecule and the other from a borate ion and a protonated diol. Similarly, the 1 : 2 ester consisted of two esters; one from a borate ion and two diol molecules and the other from a borate ion and two protonated diols. The stability constants of the esters formed were calculated based on the peak areas of the signals of the boron species on the 11B NMR spectra. The stability of an ester was strongly correlated with the electronegativity of the anchor moiety of the diol; a higher electronegativity in general yielded a more stable ester.
Bis(1-methylimidazole)iron(II) Complexes of Porphyrins Substituted with Highly Electron-Withdrawing CF3 Groups: Electronic Spectra with Split Q-Bands and MCD Spectra with Unusual Features
Authors: Yoshimura Tetsuhiko , Toi Hiroo , Inaba Shinji , Ogoshi Hisanobu
Published: July 2006

The bis(1-methylimidazole)iron(II) complexes of porphyrins substituted with one, two, or four CF3 groups at pyrrole β-positions of a porphyrin have been studied by electronic absorption and magnetic circular dichroism (MCD) spectroscopies. The splittings of Q-bands observed in the electronic spectra of the complexes may arise from asymmetrical electronic effects of the highly electron-withdrawing CF3 group on the porphyrin periphery. The ratio of absorption intensity (ε(α)/(ε(β)) decreased with an increase of the number of CF3 group, suggesting the decrease of a splitting in HOMOs. The MCD spectra of the bis(1-methylimidazole)iron(II) porphyrin complexes were markedly sensitive to the porphyrin peripheral substituents. The MCD spectra in Soret region successively changed in shape with the number of CF3 group on porphyrin periphery and consequently were apparently inverted in sign, which can be explained by the shift of maximal wavelength accompanied by a change in intensity.
AlCl3–N,N-Dimethylaniline: A Novel Benzyl and Allyl Ether Cleavage Reagent
Authors: Akiyama Takahiko , Hirofuji Hajimu , Ozaki Shoichiro
Published: July 2006

A combination system of AlCl3–N,N-dimethylaniline was found to cleave benzyl ethers readily to give parent alcohols in excellent yields. The system also cleaved allyl as well as methyl ethers. Numerous functional groups such as benzoyloxy, phenylthio, and olefinic double bond were not affected. Comparisons of AlCl3–N,N-dimethylaniline and AlCl3–anisole were described.
Thermotropic Liquid Crystals Based on Chito-Oligosaccharides. 1. Synthesis of Chitobiose Octaalkanoates and Chitotriose Undecaalkanoates and Their Thermal Properties
Authors: Sugiura Makoto , Minoda Masahiko , Watanabe Junji , Fukuda Takeshi , Miyamoto Takeaki
Published: July 2006

This paper deals with the preparation of two series of chito-oligosaccharide derivatives, chitobiose octaalkanoates, and chitotriose undecaalkanoates, in which the amino- and hydroxyl groups were blocked with alkyl pendants of differing lengths via an ester linkage. By differential scanning calorimetry(DSC) and optical microscopic observations, these compounds were found to exhibit an enantiotropic mesophase at temperatures ranging from ca. 50 °C to ca. 200 °C. The texture of the mesophases were similar to those of the discotic columnar liquid crystals formed by the cellobiose and cellotriose equivalents. However, the amido group in the chito-derivatives seems to stabilize the mesophase to an appreciable extent, bringing about higher temperatures and a longer temperature span of the mesophase than those of the cello-equivalents.
Photosensitized Oxygenation of Olefins with Zinc Tetraphenylporphine-1,4-Diazabicyclo[2.2.2]octane Complex
Authors: Sakuragi Masako , Ichimura Kunihiro , Sakuragi Hirochika
Published: July 2006

In the presence of a proper amount of amines such as 1,4-diazabicyclo[2.2.2]octane (DABCO) and piperidine, zinc tetraphenylporphine (ZnTPP) works as a not only apparently more effective but also more photoresistant sensitizer for singlet-oxygen oxygenation of olefins than in the absence of the amines. This is ascribed to the facts that ZnTPP forms a 1 : 1 complex with DABCO, and that DABCO coodinated to ZnTPP has no ability to quench singlet oxygen, as revealed by detection of singlet oxygen phosphorescence and product distributions in oxygenation of d-limonene, 1,2-dimethylcyclohexene, and 1-phenylcyclobutene.
Energy- and Electron-Transfer Pathways in the Triplet-Sensitized Photolysis of N-(1-Naphthoyl)-O-(p-toluoyl)-N-phenylhydroxylamine with Substituted Benzophenones
Authors: Sakurai Tadamitsu , Utsumi Kazuo , Ohkita Akira , Nakamura Makoto , Inoue Hiroyasu
Published: July 2006

Quantum-yield and thermodynamic analyses of the triplet-sensitized photolysis of the title hydroxylamine (NT, 1) with 4,4′-bis(dimethylamino)benzophenone (BAB), 4-dimethylaminobenzophenone (DAB), 4,4′-dimethoxybenzophenone (DMB), and 3,3′-bis(trifluoromethyl)benzophenone (BFB) suggest that the BAB- and DAB-sensitized reactions proceed by a preferential electron-transfer pathway within a triplet-exciplex intermediate, formed between the triplet-state sensitizer and the ground-state NT, to give N-phenyl-1-naphthalenecarboxamide (2) and p-toluic acid (3). On the other hand, the energy-transfer pathway in this exciplex intermediate, eventually forming 2 and 3, as well as toluene (4), predominates for reactions sensitized with DMB and BFB having fewer electron-donating substituents than does the dimethylamino group of BAB and DAB. The finding that benzil, both excited singlet and triplet states of which lie below those of NT, brings about a sensitized photolysis to afford the same fragmentation products, provides strong evidence for the existence of a triplet-exciplex intermediate. In addition, evidence concerning the operation of an electron-transfer mechanism in our sensitized photolysis comes from an observation that the photolysis of NT sensitized with N,N,N′,N′-tetramethylbenzidine, the excited state of which is one of the most powerful one-electron reductants, gives the same product distribution as does that obtained by the BAB- and DAB-sensitized reactions.
Perfluoroalkylation of Olefins by Electrooxidation of Perfluoroalkanoic Acids: Relations between Product-Selectivity and Current Density and Structures of Olefins
Authors: Uneyama Kenji , Watanabe Shunsuke , Tokunaga Yukio , Kitagawa Kouichi , Sato Yasuhiro
Published: July 2006

Electrooxidation of perfluoroalkanoic acids RfCO2H (Rf = CF3, C3F7, C7F15 together with CHF2, CH2F) in the presence of electron-deficient olefins (methyl acrylate, methyl methacrylate, acrylamide, and acrylonitrile) provided perfluoroalkylated products. The electrolysis was conducted in MeCN–H2O (7 : 1) using platinum electrodes in an undivided cell. Dimerization of methyl acrylate accompanying perfluoroalkylation, occurs in 40–50% yield under 20 mA cm−2 current density. 1,2-Addition of trifluoromethyl or difluoromethyl radicals to carbon-carbon double bond predominates in acrylamide under the high current density (100–200 mA cm−2). On the other hand, 1,2-addition of trifluoromethyl and acetamido groups and 1,2-addition of trifluoromethyl and hydroxyl groups occur in the low current density ( < 5 mA cm−2) electrolysis of methyl methacrylate.
Magnetic Properties of Cobalt(II) and Nickel(II) Benzoate Adducts with Quinoline Analogues
Authors: Emori Shuji , Shima Chiemi
Published: July 2006

Various cobalt(II) and nickel(II) 3-substituted benzoate adducts with quinoline, 4-methylquinoline, and quinoxaline were prepared. They were then characterized by means of magnetic susceptibility and IR spectroscopy. The variation in their magnetic moments is discussed in terms of the basicities of the benzoate ligands as well as the coordinate-bond lengths between the benzoate oxygen and metal atoms. For the nickel(II) compounds, the formation of weak nickel(II)–nickel(II) bonding is suggested.
Synthesis and Magnetisms of Oxamido– and Oxamato-Bridged Binuclear Nickel(II)-Copper(II) Complexes
Authors: Ohba Masaaki , Shiozuka Michito , Matsumoto Naohide , Okawa Hisashi
Published: July 2006

Oxamido- and oxamato-bridged binuclear nickel(II)–copper(II) complexes [CuL1Ni(Me6[14]aneN4)](ClO4)2·H2O (1), [CuL2Ni(Me6[14]aneN4)]ClO4 (2), and [CuL3Ni(Me6[14]aneN4)]ClO4 (3) have been synthesized and characterized, where Me6[14]aneN4 = rac-(5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, H2L1 = N,N′-bis(2-pyridylmethyl)oxamide, H3L2 = N-methyl-N′-(4-methyl-6-oxo-3-azahept-4-enyl)oxamide, H3L3 = N-(4-methyl-6-oxo-3-azahept-4-enyl)oxamic acid. The cryomagnetic susceptibilities (4.2–300 K) were well reproduced by the equation derived from H = −2JSNi·SCu (SNi = 1, SCu = 1⁄2) with the J values −78.2 cm−1, −64.5 cm−1, and −72.8 cm−1 for (1), (2), and (3), respectively.
Synthesis of Water-Soluble Lanthanide Porphyrin Sandwich Complexes: Bis(tetrapyridylporphyrinato) Cerium(IV), [Ce(tpyp)2], and Bis(tetramethylpyridylporphyrinato) Cerium(IV), [Ce(tmpyp)2]
Authors: Jiang Jianzhuang , Machida Ken-ichi , Adachi Gin-ya
Published: July 2006

A reaction of tris(acetylacetonato) cerium(III), [Ce(acac)3], with tetrapyridylporphyrinato dilithium, Li2tpyp, produces a water-soluble sandwich complex bis(tetrapyridylporphyrinato) cerium(IV), [Ce(tpyp)2], in appreciable yield, which is followed by the same water-soluble sandwich complex bis(tetramethylpyridylporphyrinato) cerium(IV), [Ce(tmpyp)2], formed by methylation of the tpyp ligand in [Ce(tpyp)2].
Thermal Behavior and Mass Spectra Aspects of 1,3,5-Triazine Derivatives Based on Isocyanuric Acid
Authors: Shimasaki Choichiro , Nakayama Hiroaki , Iwaki Akiko , Tsukurimichi Eiichi , Yoshimura Toshiaki , Hasegawa Kiyoshi
Published: July 2006

Eleven 1,3,5-triazine derivatives were investigated by the use of a thermal-analysis techniques. These compounds showed a remarkable difference in pyrolytic behavior and decomposed thermally by a cleavage of the triazine ring and the liberation of water, isocyanic acid, and carbondioxide. The pyrolysis products were separated and identified by a gas chromatograph coupled to a mass spectrometer. All of the obtained information led to the proposal of a thermal degradation mechanism for the triazine derivatives, which is presented here. The main pyrolysis and fragmentation by electron impact mechanisms were classified into four categories, respectively.
Molecular Structures of Dimeric Reduction Products of Pulegone
Authors: Kikuchi Mitsuko
Published: July 2006

The molecular structures of “isobishydropulegone” and “Harries–Roeder ketol,” isomers of “bishydropulegone,” which are dimeric reduction products of pulegone, were determined as being (1S, 3′aR, 4R, 6′R, 7′aS)-7′a-hydroxy-2′,2′,3′,3′,4,6′-hexamethylspiro[cyclohexane-1,1′-octahydroinden]-2-one and (1R, 3′aS, 4R, 6′R, 7′aS)-7′a-hydroxy-2′,2′,3′,3′,4,6′-hexamethylspiro[cyclohexane-1,1′-octahydroinden]-2-one respectively by the analysis of the two-dimentional NMR spectra.
Stereoselective Decomposition of Pyrazolines Containing Trifluoromethyl Groups
Authors: Nishida Masakazu , Hayakawa Yoshio , Matsui Masaki , Shibata Katsuyoshi , Muramatsu Hiroshige
Published: July 2006

The reaction of (Z)- and (E)-6,6,6-trifluoro-4-trifluoromethyl-4-hexen-3-ones (1) with diazomethane afforded the corresponding cis- and trans-pyrazolines (2), respectively. Photochemical and thermal decompositions of the r-3, t-4-bis(trifluoromethyl)pyrazoline gave selectively r-1, t-2-bis(trifluoromethyl)-1-propionylcyclopropane (3) and 3,4-bis(trifluoromethyl)-2-ethyl-4,5-dihydrofuran (4). On the other hand, those transformations of the r-3,c-4-isomer of the pyrazoline gave a mixture of the r-1,c-2-isomer of 3, 4, and 4,5-bis(trifluoromethyl)-5-hexen-3-one (5).
Novel Synthesis of 2-Phosphinoylphospholane 1-Oxide Derivatives
Authors: Miyamoto Yasushi , Yamashita Mitsuji , Oshikawa Tatsuo
Published: July 2006

Reactions of 2-phospholene 1-oxides with N-bromoacetamide in aqueous organic solvent produced 2-bromo-3-hydroxyphospholane 1-oxides, which reacted with sodium salts of dialkyl phosphonates to afford novel 2-phosphinoylphospholane 1-oxide derivatives. A 4-phosphin-oyl-2-phospholene derivative was also prepared.
Oxidative Chlorination of 1,10-Phenanthroline and Its Derivatives by Phosphorus Pentachloride in Phosphoryl Chloride
Authors: Yamada Masaki , Nakamura Yoshio , Hasegawa Tadashi , Itoh Akinobu , Kuroda Shigeyasu , Shimao Ichiro
Published: July 2006

Some of aromatic hydrogens of 1,10-phenanthroline and its derivative, 1,10-propano-bridged 1,10-phenanthroline-2,9(1H,10H)-dione, were oxidatively substituted by chlorine atoms with excess amount of phosphorus pentachloride in phosphoryl chloride to give the polychlorinated products.
Topological Indices of Unbranched Catacondensed Benzenoid Hydrocarbons
Authors: Hosoya Haruo , Gutman Ivan , Nikolic Jasmina
Published: July 2006

The topological indices σ (recently proposed by Merrifield and Simmons) and Z (put forward by one of the present authors, Bull. Chem. Soc. Jpn., 44, 2332 (1971)) of unbranched catacondensed benzenoid hydrocarbons are examined and their dependence on molecular structure is established. Approximate formulas are deduced, enabling an easy and accurate calculation of σ and Z.
ENDOR Study of the Cation Radicals of Vitamin E Derivatives. Relation between Antioxidant Activity and Molecular Structure
Authors: Mukai Kazuo , Uemoto Yuichi , Fukuhara Masami , Nagaoka Shin-ichi , Ishizu Kazuhiko
Published: July 2006

An ENDOR study of vitamin E derivatives was carried out. The molecular structures of the cation radicals of models for vitamin E derivatives were determined by means of ENDOR. The relation between the antioxidant activity and the molecular structure of vitamin E was discussed.
The Intramolecular Structure of Oxonium Ion in Concentrated Aqueous Deuterochloric Acid Solutions
Authors: Kameda Yasuo , Uemura Osamu
Published: July 2006

Time-of-flight (TOP) neutron diffraction experiments have been carried out for pure liquid D2O and concentrated aqueous deuterochloric acid solutions (DCl)x(D2O)1−x (x = 0.10, 0.23). The errors due to the inelasticity effect on the molecular structure in the solution were markedly reduced by the TOF measurement at the small scattering angle (2θ=44°). From the least square fit of the theoretical intramolecular interference function to the observed one, the internuclear distances, rOD and rDD, and the root mean square displacements, lOD and lDD, in both D3O+ and D2O molecules were determined as follows; rOD = 1.04(4) Å, rDD = 1.63(5) Å, lOD = 0.07(2) Å and lDD = 0.12(6) Å for D3O+, and rOD = 0.983(5) Å, rDD = 1.55(4) Å, lOD = 0.067(8) Å, and lDD = 0.12(4) Å for D2O. The bond angle ∠DOD in D3O+ was also calculated to be 103°. The trigonal pyramidal structure of oxonium ion in the liquid phase has been lead through this investigation.
Preparation and Characterization of Cobalt(III) Complexes Containing 1,1′-Bis(diphenylphosphino)ferrocene (dppf) or 1,1′-Bis(dimethylphosphino)ferrocene (dmpf) as a Bidentate Ligand, and Molecular Structures of [Co(acac)2(dmpf)]B(C6H5)4 and [Co(dtc)2(dmpf)]B(C6H5)4 (acac = 2,4-pentanedionate ion, dtc = dimethyldithiocarbamate ion)
Authors: Adachi Masahiro , Kita Masakazu , Kashiwabara Kazuo , Fujita Junnosuke , Iitaka Naoyuki , Kurachi Saeko , Ohba Shigeru , Jin Dou-man
Published: July 2006

Four new complexes, [Co(acac or dtc)2(dppf or dmpf)]X (X = BF4, B(C6H5)4) have been prepared and characterized by absorption and 1H NMR spectra, and electrochemical measurements. The [Co(acac)2(dppf)]+ complex exhibits the first d-d band at much lower energy than that of [Co(acac)2(dppe)]+ (dppe = 1,2-bis(diphenylphosphino)ethane), while the other complexes give the bands at similar energies to those of the corresponding diphosphine complexes. The structures of two dmpf complexes have been determined by the X-ray diffraction method. Crystal data are: [Co(acac)2(dmpf)]B(C6H5)4 (1), monoclinic, P21/a, a = 20.366(4), b = 13.513(2), c = 16.860(2) Å, β = 108.09(2)°, V = 4411(1) Å3, Z = 4, R = 0.041 for 5774 reflections. [Co(dtc)2(dmpf)]B(C6H5)4 (2), monoclinic, C2/c, a = 33.573(7), b = 10.148(1), c = 31.039(6) Å, β = 123.13(1)°, V = 8856(2) Å3, Z = 8, R = 0.044 for 6323 reflections. In these complexes dmpf functions as a bidentate chelate ligand with the Co–P bond distances of 2.250(1)–2.257(2) Å and the P–Co–P chelate angles are 101.09(4)° in 1 and 102.3(1)° in 2. The trans influence of the phosphino donor group is observed on the Co–O (ca. 0.04 Å) and Co–S (ca. 0.03 Å) bond distances.
Free Radical Alkylation of 1,3-Dimethyluracils and Caffeine with Benzoyl Peroxide
Authors: Itahara Toshio , Ide Naoko
Published: July 2006

Reaction of 1,3-dimethyluracil and 1,3,6-trimethyluracil with benzoyl peroxide in cyclohexane, ethyl acetate, and acetonitrile gave the corresponding 5-alkyl-1,3-dimethyluracils, although a steric effect of the methyl group at 6-position complicated the reaction. On the other hand, a similar treatment of 1,3-dimethylthymine led to alkylation of the methyl group at 5-position. The reaction of caffeine gave 8-alkylcaffeines and alkyl acetates were used as favorable solvents with respect to synthesis of 8-alkylcaffeines.
Simultaneous Generation of t-BuO· and t-BuOO· from the Decomposition of 2,2-Bis(t-butyldioxy)propane. A New Synthetic Method for Introducing a t-BuOO Group into Organic Molecules
Authors: Watanabe Yasumasa , Ohta Kenjiro , Suyama Shuji
Published: July 2006

A free-radical synthetic method for introducing a t-BuOO group into various organic substrates has been developed using 2,2-bis(t-butyldioxy)propane (1a) which can efficiently give two oxygen-centered radicals, t-BuO· and t-BuOO·, by thermolysis. The thermal reaction of 1a with cumene afforded the desired dialkyl peroxide, t-butyl 1-methyl-1-phenylethyl peroxide, in good yield (53% based on 1a reacted) together with an appreciable amount of a dimer, 2,3-dimethyl-2,3-diphenylbutane, as a by-product. The addition of t-BuOOH increased the yield of the dialkyl peroxide to as high as 82%, by suppressing the dimer formation ( < 10%). Also, reaction with isobutyronitrile and isopropyl methyl ketone gave good yields of dialkyl peroxides. The present method makes it possible to prepare unsymmetrical dialkyl peroxides containing functional groups, if the substrates are good hydrogen donors.
Electronic Absorption and Phosphorescence Spectra of 2-Acetylfuran. Conformations in the Ground and Excited Triplet States
Authors: Okubo Jun , Hoshi Toshihiko , Ono Isao , Watanabe Seiichi , Kobayashi Michio , Inoue Hiroyasu
Published: July 2006

The electronic absorption and phosphorescence spectra of 2-acetylfuran were measured in various media at room and low temperatures. It was found that 2-acetylfuran exists as an equilibrium mixture of the O–O s-cis and O–O s-trans conformers in polyethylene (PE) film. Here, the O–O s-trans conformer was considered to be a major species, and the O–O s-cis conformer a minor species in a nonpolar medium such as PE. On the other hand, in a polar medium such as poly(vinyl alcohol), 2-acetylfuran existed almost completely as the s-cis conformer. The 0–0 phosphorescence bands of the O–O trans- and cis-species were at 447 and 427 nm in PE, respectively. The S1 states for both conformers are nπ* in character, while the T1 states are π π*.
A Stereocontrolled Synthesis of (4aS, 8aR)-(+)-7,7- Ethylenedioxy-4,4,8a-trimethyloctahydro-2(1H)-naphthalenone
Authors: Kato Michiharu , Watanabe Masataka , Masuda Yoshiaki
Published: July 2006

A stereocontrolled synthesis of (4aS, 8aR)-(+)-7,7-ethylenedioxy-4,4,8a-trimethyloctahydro-2(1H)-naphthalenone, which will act as a versatile building block for the asymmetric synthesis of natural products possessing a trans-1,1,4a-trimethyldecalin unit, was accomplished starting with (1R,4S,5R)-(+)-4,6,6-trimethyl-4-vinylbicyclo[3.1.1]-heptan-2-one, readily accessible from (+)-nopinone.
Treatment of Dimethoxyparacyclophanes with Ammonium Cerium(IV) Nitrate
Authors: Takeshita Michinori , Tsuzuki Hirohisa , Tashiro Masashi
Published: July 2006

The treatment of dimethoxy[n]paracyclophanes (n = 7–12) (5), [2]paracyclo[2]thiophenophane (13), and dimethoxy[2.2]paracyclophane (8) with CAN in MeCN–water afforded 2,4-cyclohexadien-1-ones 9, [8]paracyclophanedione 10, the ring-opened esters 11, and ketones 12. When the n value of 5 was 7, 8, or 9, rearrangement of the methylene bridge occurred and 9 was obtained as the main products. With the n value of 12, quinone 10 was the main product. Whereas, treatment of 13 with CAN afforded the ring-opened ester 14 as the sole product. These results show that formation of 9 is dependent on the strain of the paracyclophanes. Epoxide A was proposed as an intermediate of these reactions.
Catalytic Conversion of Diethyl Tartrate into Pyruvate over Silica-Supported Potassium Disulfate
Authors: Sugiyama Shigeru , Fukunaga Sadao , Kawashiro Katsuhiro , Hayashi Hiromu
Published: July 2006

Potassium hydrogensulfate (KHSO4), which melts at a lower temperature of 197 °C, was adapted for vapor-phase fixed-bed flow operations as a silica-supported potassium disulfate (K2S2O7/SiO2) to afford 60% ethyl pyruvate continuously from the tartrate at 300 °C. The catalyst was effective for the intramolecular dehydration of glycol moieties, much less active for hydrolysis of esters, and capable of converting enol- to keto-form for the intermediate oxalacetate in favor of pyruvate. A TGA analysis revealed that KHSO4 was converted to K2S2O7 at 300 °C, this was in consistent with the XRD analysis.
Crystal Structures and Molecular Packing of Tetrakis(alkylthio)tetrathiafulvalene (TTCn–TTF); (Part II) (n = 7,9,11)
Authors: Nakano Chikako , Mori Takehiko , Imaeda Kenichi , Yasuoka Noritake , Maruyama Yusei , Inokuchi Hiroo , Iwasawa Naoko , Saito Gunzi
Published: July 2006

The crystal structures of tetrakis(alkylthio)tetrathiafulvalene (TTCn–TTF) with long alkyl chains (7 ≤ n ≤ 11) can be divided into two different groups (Form I and Form II) according to the difference in the arrangement of the alkyl chains. Although the crystals of TTC7–TTF exhibit two phases (triclinic and monoclinic), the stacking manner of these phases is nearly the same, Form II. TTC9–TTF crystallizes in two different forms: Form I (the triclinic phase) and Form II (the monoclinic phase). The TTC11–TTF crystal only adopts the Form I structure. Although the molecules in both forms have chair-like shapes and columnar structures, the alkyl chains in the Form I crystals are arranged parallel to each other, resulting in more strongly fastened packing than in the case of the Form II crystals. These results are associated with changes in the electrical resistivities and activation energies of TTCn–TTF over the range of large n.
Equation of State of the Fluid Defined by the Modified Buckingham (exp-6) Potential Derived by Molecular Dynamics Simulations
Authors: Kataoka Yosuke
Published: July 2006

Molecular dynamics simulations have been performed in a wide range of the temperature-density space. The calculated energy and pressure were fitted to obtain the equation of state of the modified Buckingham (exp-6) potential system. This potential function has three parameters; the size, energy, and steepness parameters in the exponential repulsion term. The Helmholtz free energy measured from the ideal gas was expanded in a series of temperature, density, and the steepness parameter. The liquid-gas critical point was examined as a function of the steepness parameter. The liquid–vapor phase boundary was compared with that of the Lennard–Jones fluids. The results reveal how entropy, energy and pressure depend on the steepness parameter.
X-Ray Structural Study of trans-[CoCl2(232N415)]ClO4 (232N415 = 1,4,8,11-Tetraazacyclotricosane)
Authors: Kawano Shigeki , Ohba Shigeru , Tsuchimoto Masanobu , Fujita Junnosuke
Published: July 2006

The structures of two isomers of trans-[CoCl2(232N415)]+ in the perchlorate salt have been determined by single-crystal X-ray diffraction. Symmetry in the coordination of the macrocyclic ligand, 232N415, around the cobalt atom is absent for both isomers, and they are called C1 and C1′ isomers. C1 isomer, (1): monoclinic, space group P21/n, a = 14.600(2), b = 21.643(3), c = 8.298(1) Å, β = 100.78(1)°, V = 2575.8(6) Å3, Z = 4, R = 0.063 for 2446 observed unique reflections. C1′ isomer, (2): monoclinic, space group P21/n, a = 19.579(2) b = 7.423(1), c = 19.636(2) Å, β = 115.68(1)°, V = 2571.9(4) Å3, Z = 4, R = 0.068 for 2416 reflections. The fifteen-membered chelate ring takes a pseudo-skew form in 1 and a pseudo-envelope form in 2, as the result of the different disposition of the C atoms bonded to two N atoms of the ring, 1trans and 2cis. The Co–N bond lengths in the fifteen-membered ring are from 2.011(6) to 2.026(9) Å, which are longer by ca. 0.05 Å than the other Co–N distances in the complex cations.
Peri-Selective Cycloaddition Reactions of 3-Methoxycarbonyl-2H- cyclohepta[b]furan-2-one with 6,6-Dimethylfulvene
Authors: Yasunami Masafumi , Kitamori Yoichiro , Kikuchi Ikue , Ohmi Hajime , Takase Kahei
Published: July 2006

The cycloaddition reaction of 3-methoxycabonyl-2H-cyclohepta[b]furan-2-one with 6,6-dimethylfulvene was carried out under refluxing in ethanol, benzene, or xylene. The [4+2] cycloadduct was formed as a major product in ethanol or benzene together with the minor [8+2] cycloadduct. On the other hand, the [8+2] cycloadduct was formed as a single product in xylene. The [4+2] cycloadduct was completely changed to the [8+2] cycloadduct under refluxing in xylene by a retro–Diels–Alder reaction, a re-cycloaddition reaction followed by spontaneous decarboxylation. The structure of the [8+2] cycloadduct was clearly confirmed by chemical transformation to methyl 3-isopropyl-1H-cyclopent[a]azulene-9-carboxylate which was obtained by the hydride reduction of methyl 3-isopropylidene-3H-cyclopent[a]azulene-9-carboxylate.
Diastereoselectivity and Reaction Pathway of the Reactions of Benzaldehyde with Allylic Iodides in the Presence of Sn or Pb
Authors: Yamataka Hiroshi , Nishikawa Kazuyoshi , Hanafusa Terukiyo
Published: July 2006

The relative reactivity and stereoselectivity were determined in the Sn- or Pb-promoted reactions of substituted benzaldehydes with 3-iodo-1-propene and 1-iodo-2-butene. The reactivity data suggested that the reactions go through a direct nucleophilic addition mechanism. No indication of the occurrence of electron transfer was obtained by the dehalogenation probe experiment. The diastereoselectivity was low in the Sn/THF system but was high in Pb/DMF. Large solvent effects were observed in the erythro selectivity for the Sn-promoted reaction; erythro : threo ratio was 31 : 69 in CH2Cl2 and 84 : 16 in HMPA.
The Structure around the Nitrite Ion in Concentrated Aqueous Solutions
Authors: Kameda Yasuo , Arakawa Hiroshi , Hangai Katsuaki , Uemura Osamu
Published: July 2006

The hydration structure and intra-ionic geometry of NO2− in a 10 mol% NaNO2 solution in D2O have been determined by the time-of-flight neutron diffraction. Measurements were made with two solutions which are identical in all respects except for the isotopic substitution of nitrogen atom. It appears that there exist 3.7 ± 0.5 water molecules coordinated to NO2− with the intermolecular distance r(N···D) = 2.71 ± 0.02 Å. The intramolecular bond distance rNO and the root mean square amplitude lNO in NO2− have precisely been determined.
The Optical Properties of the Bc2DDQ Crystal and Its Solid Phase Reaction
Authors: Tanaka Masashi , Murata Shizuaki , Takeuchi Hideo , Matsuo Susumu
Published: July 2006

Benzo[c]cinnoline (Bc) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) give a charge-transfer (CT) complex with the formula Bc2DDQ. The reflection spectra of the crystal of the Bc2DDQ complex were measured and the charge-transfer degree in the Bc2DDQ complex was estimated to be about 18%. This crystal exhibits a solid-phase reaction at 138 °C. Its thermal reaction was studied by the differential scanning calorimetry, thermogravimetry and the GC/MS spectra as well as the IR and ESR spectra and the temperature dependence of the magnetic susceptibility.
An NMR Study of the Carbanions Produced from Triphenylethylene and Its Methyl-Substituted Derivatives
Authors: Fujiwara Hideaki , Yoshino Akihiro , Yokoyama Yukihiro , Takahashi Kensuke
Published: July 2006

The triphenylethylene dianion, which was produced by reducing triphenylethylene with metallic potassium in THF, was characterized by 1H and 13C NMR spectroscopy. The 1H spectrum was assigned by making spectral comparisons with those of dianions having methylphenyl groups. The 1H and 13C NMR data showed that two geminal phenyl rings were magnetically equivalent. This result indicated that a rapid rotation exists around the bond at room temperature. Extra charge distributions in the dianion were estimated; these are discussed together with the data for the other carbanions.
An Isomeric Series of Thiophene-Fused Tetracyanoquinodimethanes. I. Preparation and Physico-Chemical Properties
Authors: Kobayashi Keiji , Gajurel Chhabi L , Umemoto Kisaburo , Mazaki Yasuhiro
Published: July 2006

Four isomeric benzodithiophene analogs of 11,11,12,12-tetracyano-9,10-anthraquinodimethane have been prepared via a TiCl4 mediated condensation of the corresponding quinone and malononitrile. The reduction potential of these isomers was interpreted in terms of the resonance energies for the neutral and radical anion species. These new acceptor compounds, except for 4,8-bis(dicyanomethylene)-4,8-dihydrobenzo[1,2-c:4,5-c′]dithiophene, formed crystalline charge-transfer complexes with tetrathiafulvalene, among which the complex of 4,8-bis(dicyanomethylene)-4,8-dihydrobenzo[1,2-b:4,5-b′]dithiophene particularly exhibited a high room-temperature conductivity of 4.78 S cm−1.
An Isomeric Series of Thiophene-Fused Tetracyanoquinodimethanes. IV. Crystal Structure of 2 : 3 Charge-Transfer Salt with Tetraethylammonium
Authors: Yasui Masanori , Hirota Masamichi , Endo Yuji , Iwasaki Fujiko , Kobayashi Keiji
Published: July 2006

The crystal structure of the charge-transfer salt of one of the isomeric thiophene-fused TCNQs, 4,8-bis(dicyanomethylene)-4,8-dihydrobenzo[1,2-b : 4,5-b′]dithiophene (1), with tetraethylammonium has been determined by the X-ray method. Crystals of 2C8H20N+·(3C16H4N4S2)2− belong to monoclinic system, P21/n, Z = 2, a = 10.944(2), b = 28.765(8), c = 9.244(2) Å, β = 90.00(2)°, V = 2910(1) Å3, Dx = 1.381 Mg m−3 and Dm = 1.36(2) Mg m−3. The final R value is 0.064 for 4224 observed reflections. Two independent molecules, A and B, of 1 stack to form infinite columns along the a axis as ABBABB··· manner. The separations of the molecular planes are 3.47 and 3.39 Å, for A···B and B···B, respectively. The columns are linked side-by-side with short S···S contacts of 3.570(3) and 3.529(3) Å. From the comparison of the bond lengths of TCNQ frameworks A shows the neutral character, while B shows anionic structure.
Kinetics of the Forward and Reverse Na(I)–H(I) and K(I)–H(I) Exchanges on Antimony(V) Arsenatophosphate Cation Exchanger
Authors: Varshney Krishna Gopal , Khan Asif Ali , Khan Ashfaq Rabbani
Published: July 2006

Kinetic studies have been made on antimony(V) arsenatophosphate cation exchanger, for the forward and reverse Na(I)–H(I) and K(I)–H(I) exchange processes. On the basis of such studies the self diffusion coefficients, energies of activation, and entropies of activation have been evaluated.
Electrical Properties and Sinterability for Lithium Germanium Phosphate Li1+xMxGe2−x(PO4)3, M = Al, Cr, Ga, Fe, Sc, and In Systems
Authors: Aono Hiromichi , Sugimoto Eisuke , Sadaoka Yoshihiko , Imanaka Nobuhito , Adachi Gin-ya
Published: July 2006

The electrical properties and sinterability were studied for Li1+xMxGe2−x(PO4)3, M = Al3+, Cr3+, Ga3+, Fe3+, Sc3+, and In3+ systems. Due to the closer ionic radius of Al3+ and Cr3+ compared to that of Ge4+, those M3+ ions easily substitute the Ge4+ site. Larger cations, such as Ga3+, Fe3+, Sc3+, and In3+, were difficult to substitute the Ge4+ site. The ionic conductivity and sinterability improved with an increase in x for all of the M3+-substituted systems. In particular, an Al3+- or Cr3+-substituted system shows higher conductivity; the maximum conductivity is 2.4 × 10−4 S cm−1 at 298 K for Li1.5Al0.5Ge1.5(PO4)3. The enhancement in the conductivity is attributed to a decrease in the porosity and a lowering of the activation energy in the grain boundaries. The activation energy for Li+ ion conduction of the bulk component was 0.38 eV for Li1+xMxGe2−x(PO4)3 electrolytes, and was almost independent of M3+ substitution.
Study of Equilibria and Kinetics of the Interactions of Iron(III) with 8-Hydroxyquinoline and 8-Hydroxyquinoline-5-sulfonic Acid in HClO4–NaClO4 Media
Authors: Das Asim Kumar
Published: July 2006

The equilibria and kinetics of the reaction of iron(III) with 8-hydroxyquinoline (oxine) and 8-hydroxyquinoline-5-sulfonic acid under the condition of 1 : 1 chelate formation at different temperatures (35–45 °C) and ionic strength I = 1.0 mol dm−3 (NaClO4 + HClO4) have been studied. A dual path mechanism involving both Feaq3+ and Fe(OH)aq2+ species and the undissociated ligand (LH2+, LH2±) is consistent with the experimental observations under the experimental condition. The different rate constants have been deternined from the attainment of the equilibrium from both directions i.e., from the study of complex formation at low acid concentration and from the study of decomposition of the complex in presence of higher acid concentration. The results obtained from the both studies are found comparable within the experimental error limit. The results conform to kobsd/B = k1[H+] + k2Kh where,

; Kh = hydrolysis constant of Feaq3+, k1 and k2 are the forward second order rate constants of Feaq3+ and Fe(OH)aq2+ respectively and Q is the equilibrium constant of the reaction, Fe3+ + LH2+ FeL2+ + 2H+ where LH2+ represents the protonated form of the ligand, 8-hydroxyquinoline and a similar reaction occurs for 8-hydroxyquinoline-5-sulfonic acid (LH2±). Thermodynamic parameters for each of the steps have been determined. The results are compared with those of recent findings in the interaction of cerium(IV) with these ligands in perchloric acid media. Fe(OH)aq2+ appears to react through a purely dissociative fashion (Eigen–Tamm mechanism) and its characteristic water exchange rate has been found, as a rough estimate. On the other hand Feaq3+ appears to react through the associative interchange (Ia) mechanism. The equilibrium constants (Q) obtained spectrophotometrically have been compared with those obtained from kinetic studies.
Utilization of Enzymatic Digestion for the Study of the Macromolecular Effect in Complexation Processes. Protonation and Copper Coordination Equilibria of Hyaluronate and Its Fragments
Authors: Burger Kálmán , Sipos Pál , Illés János
Published: July 2006

The effect of enzymatic digestion on the proton and copper(II) binding ability of hyaluronate (HYA), a macromolecular polyelectrolyte, and its fragments were studied via potentiometry. The degree of depolymerization was measured by spectrophotometry. The log Kapp vs. α functions (where α is the mole fraction of dissociated carboxyl groups in the samples) and the protonation group constants were determined in the native and enzymatically partly and completely decomposed samples. The two different data treatments led to the same chemical consequences. The interaction between copper(II) and HYA was found to be less dependent on the degree of depolymerization than that between H+ and HYA, the results indicating an almost negligible role of longrange electrostatic forces in the copper(II)–HYA interaction. All the investigations demonstrated that enzymatic digestion can be used advantageously for the characterization of the macromolecular effect in coordination processes.
Dynamic NMR as a Nondestructive Method for the Determination of Rates of Dissociation. XX. Secondary Isotope Effect on Kinetic Basicity of Amine Ligands in Boronate–Amine Complexes and Ammonium Salts
Authors: Toyota Shinji , Oki Michinori
Published: July 2006

Secondary isotope effects on the kinetic basicity of amine ligands in boronate-amine complexes and ammonium salts were first determined by taking advantage of the rate constants of the dissociation of the amine ligands measured by the dynamic NMR method. The basicities of amine ligands are enhanced by the α-deuterations in the both compounds and the isotope effect caused by a deuterium is larger in the boronate complexes than the ammonium salts. These isotope effects are discussed on the basis of the inductive and steric effects.
Studies on Fused 2(1H)-Pyridenethiones: New Routes for the Synthesis of Fused 1H-Pyrazolo[3,4-b]pyridines and Fused Thieno[2,3-b]pyridines
Authors: Al-Kaabi Sharifa Soltan , Elgemeie Galal Eldin Hamza
Published: July 2006

A synthesis of fused 1H-pyrazolo[3,4-b]pyridines and fused thieno[2,3-b]pyridines utilizing fused 2(1H)-pyridinethiones as starting components is described. The structures of the products were assigned and confirmed on the basis of their elemental analysis and spectral data.
Studies on Fused β-Lactams: Synthesis of 1-Aza Analogs of Cephem
Authors: Sharma S D , Kaur Verinder , Bhutani Punita , Khurana J P S
Published: July 2006

Annelation of 2-methylthio-3,4-dihydropyrimidine (3) with two moles of phenoxyacetyl chloride in presence of triethylamine did not yield the expected β-lactam (6) and instead the N-acylated compound 5a was obtained. Various N-acylated pyrimidines 5a–d also failed to yield any β-lactam. However, β-lactam ring has been conveniently grafted on to 2-methylthio-3,6-dihydropyrimidines 9a–d, 12 by annelating them with in situ prepared aryloxyketenes to furnish novel 1-aza analogs of cephem 10a–e and 13.
Terminal–Terminal Types of Liquid Crystals. III. Thermal and Electrooptical Behavior of Liquid Crystalline Bis[urethane]s
Authors: Sugiyama Kazuo , Kato Koichi , Shiraishi Kohei
Published: July 2006

Novel terminal-terminal types of liquid crystalline bis[urethane]s 3, prepared from (S)-2-methylbutyl 4-[4-(11-hydroxyundecyloxy)benzylideneamino]cinnamate 2 and various diisocyanates, were studied by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Bis[urethane]s 3c obtained from 1,3-diisocyanatobenzene and 3d from 2,4-diisocyanatotoluene exhibit a smectic state, while bis[urethane]s 3a obtained from 1,6-diisocyanatohexane, 3b from bis(4-isocyanatophenyl)methane and 3e from 2,6-diisocyanatotoluene show no mesophases. It was found from IR spectroscopic results that inter- and intramolecular hydrogen bondings due to N–H and C=O of urethane bonds play an important role in the formation of mesophase. The dual-frequency drive, based on light scattering driven by the application of an a.c. current at different frequencies, was studied in the smectic A state of 3c and 3d: τr at 0.1 Hz are 0.84 and 0.25 s, τr at 1 kHz are 9.75 and 8.95 s for 3c and 3d, respectively.
Formation of Zinc Oxide by Homogeneous Precipitation Method
Authors: Fujita Kazumi , Matsuda Keizo , Mitsuzawa Shunmei
Published: July 2006

The process of ZnO formation depends on the concentration of ZnCl2 and the (CH2)6N4/ZnCl2 molar ratio(R), and there are two routes leading to ZnO: One is its direct formation, and the other is via Zn5Cl2(OH)8 as an intermediate.
Bis{2-(dimethylphosphino)ethane-1-thiolato}-nickel(II), -palladium(II), and -platinum(II) Complexes, and Molecular Structure of the Nickel(II) Complex
Authors: Kita Masakazu , Yamamoto Takashi , Kashiwabara Kazuo , Fujita Junnosuke
Published: July 2006

Bis{2-(dimethylphosphino)ethane-1-thiolato} complexes Ni(II), Pd(II), and Pt(II) were newly prepared, and the molecular structure of the Ni(II) complex was determined by X-ray analysis to have a square planar trans(P,P) geometrical configuration. The 1H, 13C, and 31P NMR spectra of the complexes in CDCl3 indicate a trans(P,P) structure for the nickel(II) and palladium(II) complexes and a cis(P,P) one for the platinum(II) complex.
X-Ray Crystal Structure of Silver(I) Complex with 1,3-Bis(8-quinolylthio)propane
Authors: Yuchi Akio , Shiro Motoo , Wada Hiroko , Nakagawa Genkichi
Published: July 2006

An X-ray crystal structure has been determined for a silver(I) complex with 1,3-bis(8-quinolylthio)propane (BQTP), Ag(BQTP)NO3. Since a conformational sequence of sc-ap-ap-sc, inherently preferred by the S–C–C–C–S back-bone, is kept in the silver(I) complex, BQTP does not coordinate to a single metal ion, but forms polymeric complexes. Crystal data: monoclinic, space group P21/c, a = 27.011(8), b = 7.962(1), c = 20.270(5) Å, β = 110.41(3)°, V = 4086(2) Å3, Z = 8, R = 0.037 for 5211 reflections.
Fluorescence Quenching in {Ln[Fe(CN)6]·nH2O}x (Ln = Eu(III) or Tb(III))
Authors: Sakamoto Masatomi , Matsuki Kimihiro , Ohsumi Rie , Nakayama Yusuke , Matsumoto Akira , Okawa Hisashi
Published: July 2006

Fluorescent properties of cyanide-bridged Ln(III)–Fe(III) complex assemblies, {Ln[Fe(CN)6]·nH2O}x (n = 4 for Ln = Eu; n = 5 for Ln = Tb), have been investigated in solid state in comparison with those of the 1 : 1 mixtures of K3[Fe(CN)6] and LnCl3·6H2O (Ln = Eu, Tb). Fluorescence of Eu(III) and Tb(III) is almost completely quenched in the complexes but little quenched in the mixtures.