bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical Resolution of (2-Aminoethyl)butylphenylphosphine and the Absolute Configuration Assigned on the Basis of Circular Dichroism Spectra of Its Palladium(II) Complexes
Authors: Kinoshita Isamu , Kashiwabara Kazuo , Fujita Junnosuke
Published: July 2006

(2-Aminoethyl)butylphenylphosphine was resolved with (+)D-di-μ-chlorobis[(S)-N,N-dimethyl-α-methylbenzylamine-2C,N]dipalladium(II), and the absolute configuration of the chiral phosphorus atom was assigned on the basis of the circular dichroism spectra of dichloro palladium(II) complexes with the resolved aminophosphine.
Application of the MTPA Method to Determination of Abusolute Stereochemistry. The Hydroxymethyl-substituted Chiral Carbon of Carbocycles
Authors: Sugimoto Yayoi , Tsuyuki Takahiko , Moriyama Yoshihiko , Takahashi Takeyoshi
Published: July 2006

Application of the MTPA method is extended to determination of the absolute configuration of primary alcohols such as furanoeremophilan-14-ol and 17β-(hydroxymethyl)androst-5-ene with a hydroxymethyl group on the chiral ring carbon atom of carbocycles.
Amine Base-catalyzed H-D Exchange Reaction of 2,3,4-Trimethyl-thiazolium Iodide in Methanol-d4
Authors: Yano Yumihiko , Tamura Yoshiharu , Tagaki Waichiro
Published: July 2006

The rates of amine base-catalyzed H-D exchange of 2-methyl hydrogens of 2,3,4-trimethylthiazolium iodide were measured in deuterated methanol by using following amines: α-picoline, imidazole, 2- and 4-aminopyridine. The results indicated that the reaction was subject to a general base catalysis. The solvent effect is also described.
Adsorption of Orthophosphate on a Synthetic Silica–Alumina
Authors: Tokunaga Shuzo , Shiokawa Jiro
Published: July 2006

The characteristics and mechanism of the adsorption of orthophosphate on a commercial synthetic silica–alumina, Neobead D, were studied. The adsorption rate increased with decrease in pH and increase in the dose of silica–alumina below the concentration of 4 g dm−3. The adsorption almost terminated in 24 h, but a very slow reaction was observed even after 3 d. The adsorption isotherm follows the Freundlich equation, the inflection in the log-log plot indicating difference in the adsorption mechanism between low and high phosphate concentrations. The adsorption capacity increased with decrease in pH, being the highest at an initial pH of 3.0. The silica–alumina exhibited buffer action, phosphate-free solutions of pH 4–10 showing pH of ca. 6 after 24 h. In coincidence with and in proportion to the adsorption, release of hydroxide, sulfate and silicate ions occurred in the reaction of initial pH of 4.7. The sum of the equivalents of the three anions released could well account for the moles of phosphate adsorbed. The adsorption thus proceeds mainly through the ion-exchange process between phosphate in solution and the anions on the solid, univalent phosphate ions taking part in the reaction.
Lifetimes of ortho-Positronium in Benzene Solutions of β-Diketonates of Iron(III) and Cobalt(III)
Authors: Endo Kazutoyo , Furukawa Michiaki , Yamatera Hideo , Sano Hirotoshi
Published: July 2006

The lifetimes of ortho-positronium (o-Ps) have been measured in benzene solutions of β-diketonates of iron(III) and cobalt(III). A trend in substituent effect on the acceleration of o-Ps decay has been found. A substituent such as trifluoromethyl, that tends to withdraw electrons from the chelate ring, greatly accelerated o-Ps decay; the greatest rate constant observed was 33.8×109 M−1 s−1 for tris(hexafluoroacetylacetonato)iron(III). An electron-releasing substituent such as t-butyl accelerated o-Ps decay to a lesser extent, e.g. 10.5×109 M−1 s−1for tris(dipivaloylmethanato)iron(III). The extent to which a complex accelerated o-Ps decay was largely related to the redox potential, which was observed by cyclic voltammetry. Complexes with phenyl substituents in the ligand showed slightly smaller effects than that suggested by their redox potentials.
Picosecond Spectroscopy Studies of the Intersystem Crossing of Aromatic Carbonyl and Nitro Compounds in Solution
Authors: Ohtani Hiroyuki , Kobayashi Takayoshi , Suzuki Kaoru , Nagakura Saburo
Published: July 2006

The build-up time constants of Tn←T1 transition bands were measured with 4-hydroxybenzophenone, Michler’s ketone, 2-nitrofluorene, 1-nitropyrene, and 9-nitroanthracene in solution with the aid of picosecond spectroscopy. All the compounds exhibit fast build-up of the Tn←T1 absorption with the time constants smaller than 100 ps. The picosecond kinetics of these nonfluorescent compounds are interpreted in terms of the electronic structures of initial and final states relevant to radiationless transitions.
Ab Initio Calculation of Force Constants of Hydroxylamine
Authors: Hamada Yoshiaki , Tsuboi Masamichi , Umeyama Hideaki
Published: July 2006

Ab initio molecular orbital calculation has been applied to hydroxylamine molecule to reach a reliable set of force constants by the use of the 4-31G basis set. This approach was found to be an enlightening way to solve a problem of the so far undeterminable amino twisting frequency. For this, the value of 1250±100 cm−1 was estimated. A few comments are also given on the theoretical and experimental values of force constants.
Hydration Numbers of Sodium Chloride in Dioxane–Water Mixtures and the Volume Change Accompanying Hydration
Authors: Okuwa Tsunemichi
Published: July 2006

The density and the ultrasonic velocity were measured for dioxane–water solutions of sodium chloride at 25 °C. The hydration numbers of sodium chloride were estimated and were compared with those determined by electricalconductivity measurements. The difference between them was discussed. The volume change caused by the dissociation of sodium chloride in a 60 wt % aqueous dioxane solution was determined from the data of the apparent molal volume. This value is in good agreement with that calculated from the excess ultrasonic absorption.
Polar Fluorescent State of 1- and 2-Acylanthracenes. II. The Perturbation of Protic Solvents
Authors: Tamaki Takashi
Published: July 2006

The steady-state and time-resolved fluorescence spectra were measured for protic solutions of 1- and 2-acetyl- or 1- and 2-benzoylanthracenes at various temperatures. It has been demonstrated that the perturbation of protic solvents on the fluorescence spectra is caused by a combination of the orientational dipolar solvent-solute relaxation and the hydrogen bond interaction. Based on the time-dependent spectral shift and the temperature dependence of fluorescence polarization observed for 2-acylanthracene, the relaxation process of the excited solute has been supposed to involve the level inversion of dual fluorescent states, which respond differently to the solvation of the system.
Complex Formation and Ionization in 3,5-Dialkyl-4-hydroxybenzylidenemalononitrile in the Ground State, and Non-radiative Relaxation in the Excited State
Authors: Mizukoshi Hiroko , Itoh Michiya
Published: July 2006

The interaction of 3,5-dialkyl-4-hydroxybenzylidenemalononitrile (HO-BMN) with ethanol, pyridine, and triethylamine in hexane gives rise to a hydrogen bonding complex formation in a low concentration of ethanol (pyridine and triethylamine) at room temperature. For ethanol concentration >5 mol dm−3, the H-bonded complex exhibits further interaction with another ethanol (pyridine and triethylamine) molecule leading to the formation of anion form of this compound. However, no excited-state proton transfer was observed in several solvents. HO-BMN is fairly fluorescent in a solid solution of boric acid glass at room temperature, as well as in the rigid organic solution at 77 K, but almost non-fluorescent in fluid media at room temperature (φ≈10−4). The non-radiative process of HO-BMN in fluid media is discussed in terms of torsional relaxation of the excited state.
Topological Ligand Design. II. The Definition and Derivation of Extended and Complex Ligand Graphs
Authors: Takamoto Susumu
Published: July 2006

An extended ligand graph is a set of several points corresponding to donor atoms, where each pair of points is connected by n lines when these atoms are able to form n chelate rings with a metal ion. These graphs can cover all the ligands, but they may not express the geometrical patterns of some complicated ligands clearely enough for them to be discriminated. A complex ligand graph is a set of some main points and sub-points connected by sub-lines, where the main points, sub-points, and sub-lines correspond to donor atoms, carbon atoms forming chelate bonds, and chemical bonds among them respectively. All the complex ligand graphs can then be systematically derived from donor-atomic graphs, which are composed of only main points and main lines and are equivalent to the simple ligand graphs previously designed. Another designing method of ligands is proposed for a certain coordination sturcture. A complex ligand graph to which no more sub-points or sub-lines can be added is called a parent ligand graph. Then all the complex ligand graphs for such a coordination are derived from the parent ligand graphs by neglecting some sub-points or by removing some sub-lines successively.
Solution Properties of Phycocyanin. VI. The Characterization of the Phycocyanin Monomer
Authors: Saito Takahide , Iso Naomichi , Mizuno Haruo , Ozeki Fumiaki , Matsui Yoshiyuki
Published: July 2006

The monomer molecular weight of phycocyanin was determined by sedimentation equilibrium measurements in 6 mol/1 guanidine hydrochloride (GndCl) and by sodium dodecyl sulfate (SDS)–polyacrylamide gel electrophoresis. The former measurement gave the monomer molecular weight of 4.0×104. From the latter, the phycocyanin was found to be composed of two kinds of subunits, the molecular weights of which were 1.7×104 and 2.0×104. Assumimg that the phycocyanin monomer consists of two polypeptide chains, the molecular weight becomes 3.7×104. These values coincide with the value of 4.2×104 assumed in our previous works, which corresponds to onesixth of the hexamer molecular weight. The sedimentation coefficient, s25w, was 2.21 Svedberg unit, and the intrinsic viscosity in 6 mol/1 GndCl was 19.5 ml/g, at 25.0 °C. From these values, it was clear that the phycocyanin monomer was unfolded in the solvent.
A Plot of the pH vs. the Logarithm of the Titrant Volume in Potentiometric Titration. The Determination of Phenol in Water
Authors: Kamakura Katsuyoshi
Published: July 2006

The determination of phenol in water was successfully carried out by means of a new plot of the potentiometric titration data. The plot of the pH vs. the logarithm of the titrant volume gave a titration curve with an inflection between two linear portions, and the center of the inflection obtained by a graphical method was found to correspond to the equivalence point. In the titration of phenol, the data fitted well to the theoretical curve by taking into account the hydrolysis of the phenol ion. The mean of the results obtained from the apparent equivalence point in the concentration range of 1.0–7.7×10−3 mol dm−3 was 101.2% of the results obtained iodometrically after the bromination of phenol, and the precision of the results was ±2.7% (S.D.).
Kinetic Studies of the Acid Hydrolysis of Aquaoxo[N-(2-pyridylmethyl)iminodiacetato]vanadium(IV) and Aqua(nitrilotriacetato)oxovanadate(IV) in Aqueous Perchloric Acid Solution
Authors: Nishizawa Masato , Saito Kazuo
Published: July 2006

Acid hydrolysis of aquaoxo[N-(2-pyridylmethyl)iminodiacetato]vandium(IV) [VO(pmida)H2O], ([H+]=0.1–2.0 M, 1M=1 mol dm−3) and aqua(nitrilotriacetato)oxovanadate(IV) [VO(nta)H2O]−, ([H+]=0.2–2.0 M) has been studied by the stopped-flow method in aqueous perchloric acid solution at an ionic strength 2.0 (LiClO4). The pseudo first-order rate constant ko is dependent on the proton concentration. The rate formula is expressed by ko=(k1K1[H+]+k2K1K2[H+]2)⁄(1+K1[H+]+K1K2[H+]2). A simulation curve fitting treatment gave the figures: k1=0.02 and 0 s−1, k2=6 and 3000 s−1, K1=1.5 and 0.2 M−1, and K2=0.2 and 0.004 M−1 at 25 °C for [VO(pmida)H2O] and [VO(nta)H2O]−, respectively. These data indicate that the rate determining step corresponds to the dissociation of the second basal bond of the singly or doubly protonated oxovanadium(IV) complexes.
Reactions of CO2 with Cu(I) Alkoxides and Amides to Give Alkylcarbonato-, μ-Carbonato-, Hydrogencarbonato-, and Carbamato-copper Complexes
Authors: Yamamoto Takakazu , Kubota Minoru , Yamamoto Akio
Published: July 2006

Carbon dioxide reacts with ROCu(PPh3)2 (R=C2H5, C6H5CH2; PPh3=triphenylphosphine) to produce ROCO2Cu(PPh3)2. Hydrolysis or thermolysis of the alkylcarbonatocopper(I) complexes gives a binuclear carbonatocopper(I) complex (PPh3)2CuOCO2Cu(PPh3)2, which is further converted into a hydrogencarbonatocopper(I) complex [HOCO2Cu(PPh3)2]n by the reaction with CO2 in moist solvents. The IR spectrum of [HOCO2Cu(PPh3)2]n shows association of the HOCO2Cu(PPh3)2 units through hydrogen bonds. The IR spectrum of [HOCO2Cu(PPh3)2]n also reveals that the mode of the association depends on conditions of the crystallization of the complex. The reaction of (PPh3)2CuOCO2Cu(PPh3)2 with CH3I gives (CH3O)2CO and the reaction of [HOCO2Cu(PPh3)2]n with C6H5NH2 affords C6H5NHCO2Cu(PPh3)2 in high yields. Carbon dioxide reacts also with an amidocopper(I) complex C6H5NHCu(PPh3)2 to yield a carbamatocopper(I) complex C6H5NHCO2Cu(PPh3)2. The reaction of CH3Cu(PPh3)2(diethyl ether)0.5 with CO2 in the presence of HN(C2H5)2 affords (C2H5)2NHCO2Cu(PPh3)2. The isocyanate group of phenyl isocyanate is inserted into the C2H5O–Cu bond of C2H5OCu(PPh3)2 to give a (ethyl N-phenylcarbamato)copper complex.
Asymmetric Transformation of α-Amino Acids Promoted by Optically Active Cobalt(III) Complexes. II. N-Methylalaninatocobalt(III) Complexes with Tetramines
Authors: Yamaguchi Motowo , Yano Shigenobu , Saburi Masahiko , Yoshikawa Sadao
Published: July 2006

The preparation and structural assignments of N-methyl-(S)- and -(R)-alaninatocobalt(III) complexes with a few chiral derivatives of 2,3,2-tet (=3,7-diazanonane-1,9-diamine) and triethylenetetramine are described. The hydroxide ion-catalyzed epimerizations of these complexes are examined at pH 10. In the N-methylalaninato complexes the isomer ratio for Λ-S/Λ-R ranged from 76/24 to 90/10. In the most favorable case where tetramine is 2(S)10(S)-4,8-diazaundecane-2,10-diamine (abbreviated as 2(S)10(S)-Me2-2,3,2-tet) the energy differences among the four possible diastereomers are discussed in relation to the prediction from strain energy minimization calculations.
Structure of a Guaioxide-type Sesquiterpene from “San-shion”
Authors: Hirota Hiroshi , Tanahashi Yoshiaki , Takahashi Takeyoshi
Published: July 2006

The structure including absolute stereochemistry of “LB”, one of the volatile constituents of “San-shion” (the roots of Ligularia species), was found to be (1S,4R,5S,7R,10R)-5,11-epoxyguaiane.
Studies of the Hydrous Titanium Oxide Ion Exchanger. V. The Stability of the Hydrogen Form in Air
Authors: Inoue Yasushi , Yamazaki Hiromichi
Published: July 2006

After being allowed to stand in air at room temperature, the exchanger in the hydrogen form showed an abrupt decrease in its ion-exchange capacity between 3 and 6 months after the preparation. This is attributable to the preferential destruction of the most acidic hydroxyl groups by dehydrating condensation.
Structural Dependence in a One-electron Transfer Process: Naphthalene peri Ketones
Authors: Sato Takeo , Kubo Masao , Nishigaki Kenji
Published: July 2006

The cyclic voltammetry of several naphthalene peri ketones was carried out in anhydrous DMF containing TBAP. The cathodic peak potential for carbonyl reduction was found to be shifted toward a more anodic potential when carbonyl, oxygen, and sulfur groups were present in the peri position. The controlled potential electrolysis of peri diketones gave an intramolecular coupling product via a bis-anion radical.
Electrolytic α-Bromination of Some α-Substituted Active Methylene Compounds
Authors: Torii Sigeru , Uneyama Kenji , Yamasaki Noritsugu
Published: July 2006

Electrolytic α-bromination of methyl α-substituted malonates and methyl α-substituted acetoacetates was accomplished in 73–84% yields in dichloromethane containing tetraethylammonium bromide as an electrolyte and sodium methoxide as an enolizing reagent.
Catalysis by Heteropolyacid. I. Polymerization Reaction of Benzyl Alcohols
Authors: Nomiya Kenji , Ueno Tetsuo , Miwa Makoto
Published: July 2006

Benzyl alcohol and its derivatives catalyzed by heteropolymolybdic acids such as H3PMo12O40 and H4SiMo12O40 have been found to polymerize, leading to the formation of polyaromatics. The properties of the polymers obtained and the function of catalysts have been studied.
On the Choice of Adsorptives for the Application of a Modified Dubinin-Radushkevich Equation
Authors: Stoeckli Fritz , Perret André , Huber Ueli
Published: July 2006

It is shown that great care has to be taken in the choice of the adsorptives for the assessment of microporosity and its heterogeneity. Methanol, for which selective interactions may occur, is not a suitable adsorptive to be used in the framework of the generalized Dubinin-Radushkevich equation proposed by Stoeckli.
Electron Spin Resonance of 2,2′-Bipyridyl, Dimethyl-2,2′-Bipyridyls, and 2,2′-Biquinolyl in their Phosphorescent Triplet States
Authors: Higuchi Jiro , Yagi Mikio , Iwaki Takashi , Bunden Makoto , Tanigaki Katsumi , Ito Takeshi
Published: July 2006

Electron spin resonance (ESR) of phosphorescent triplet states of 2,2′-bipyridyl, 3,3′-, 4,4′-, 5,5′-, and 6,6′-dimethyl-2,2′-bipyridyls, and 2,2′-biquinolyl has been studied in ethanol glasses. For 2,2′-bipyridyl, the ESR spectrum of both the E and Z conformers was observed in poly(vinyl alcohol) films and their assignment was examined by changing the direction of applied magnetic field. Using such a technique, the stretched polymer-film method has been developed for determining the molecular conformations which are difficult to be estimated from zero-field splitting (ZFS) parameters obtained in rigid glasses. As a result, the conformations in the phosphorescent triplet states of molecules studied here are confirmed to be all E in ethanol glasses, even for a case with a relatively small E value.
Formation and Spectral Properties of Some Bis(β-diketonato)copper(II)–Diazole Complexes
Authors: Kogane Tamizo , Hirota Reiko
Published: July 2006

The reactions of bis(β-diketonato)copper(II) with pyrazole and imidazole gave the diazole adducts Cu(β-dik)2(Hdzl) (β-dik=β-diketonate anion; Hdzl=diazole) and/or the μ-diazolato complexes [Cu(β-dik)(dzl)]n (n=2,4,….). The complexation reactions are very sensitive to the nature of the diazole and to the reaction conditions, sometimes giving different products depending upon the solvent used. In chloroform, Cu(β-dik)2-pyrazole and Cu(β-dik)2-imidazole complexes exhibited characteristic absorption maxima at approximately 570 and 555 nm, respectively, which are much shorter than the λmax values of the starting Cu(β-dik)2 chelates.
Minimum-energy Conformation of Different Tropocollagen Models Calculated for Poly(Gly–Pro–Pro) by Considering Helical Constraints
Authors: Okuyama Kenji , Eto Haruaki , Nakaya Ikuo , Takayanagi Motowo
Published: July 2006

The minimum conformational energies for three helical models of tropocollagen were calculated by using energy functions and values of parameters obtained by Momany et al.. Three types of helical models containing 7/1, 10/1, and 12/1 helices were employed. Among the models with the 7/1 helix, only the conformation having the N(Gly1)···O(Pro2) type hydrogen bond was found to be energetically stable. Thus all the three helical models had the same type of hydrogen bond. The minimum-energy conformation of the 7/1 helix model was found to be more stable than those of the other two models by about 7 kcal/mol per tripeptide unit. This difference mainly came from the non-bonded energy terms of both intra- and inter-chains. Since the conformation of the 7/1 helix model was widely spread in the conformational space compared with those of the other models, it was concluded that the unit twist of the 7/1 helix model is well suited for peptide chains to conform a triplehelical structure. The above results strongly supported the 7/1 helix model for tropocollagen.
ECE Mechanism as a Tool for the Investigation of Unstable Metal Complexes. II. Current-Potential Characteristics for the Reversible Deposition of an Insoluble Species: Case of Electrochemical Reduction of trans-Dibromobis(ethylenediamine)cobalt(III) Complexes
Authors: Yamada Akifumi , Yoshikuni Tadatsugu , Kato Yoshikiyo , Tanaka Nobuyuki
Published: July 2006

Theoretical relations were derived for the ECE mechanism involving the reversible deposition of an insoluble species at constant potential (potentiostatic method). Assuming that the activity of deposit becomes equal to unity immediately after the beginning of electrolysis, current-potential relations were obtained for the case in which the first electron transfer step is irreversible and the second one, reversible. The method was used to study the acid hydrolysis of bivalent cobalt complex in the reduction of trans-dibromobis(ethylenediamine)cobalt(III) complex. The measurement made at 5 °C in 0.1 M acetate buffer solutions (pH 4.8) gave 0.4 s−1 for the acid hydrolysis of trans-dibromobis(ethylenediamine)cobalt(II) which was produced by the reduction of cobalt(III) complex.
Pyrolytic Sulfurization Gas Chromatography. VI. The Continuous and Simultaneous Determination of the Atomic Ratio between C, H, O, and N in Various Compounds
Authors: Hara Tadashi , Fujinaga Kaoru , Okui Fujio
Published: July 2006

The simultaneous determination of the atomic ratio between C, H, O, and N in various compounds including a metal organic chelate one has been presented in our previous papers. With the objective of reducing the analysis time, an apparatus by which a continuous and simultaneous determination of the atomic ratio between C, H, O, and N can be carried out has been newly designed and constructed. Using this apparatus, many samples can be treated continuously at the rate of about 20 min for one sample, with satisfactory results.
Metal Complexes of Amino Acids. XII. The Deuteration of α-Hydrogen Atoms in Cobalt(III) Complexes Containing α-Amino Carboxylates
Authors: Ama Tomoharu , Kawaguchi Hiroshi , Kanekiyo Makoto , Yasui Takaji
Published: July 2006

The second-order rate constants (rate=kD(base)[Complex][OD−]) for the deuterium exchange of α-methylene or α-methine protons in the amino carboxylato complexes, trans(O)-, C1-cis(O)-, and C2-cis(O)-[Co(gly)2(en)]+ and -[Co(gly)2(tn)]+, [Co(gly)(NH3)4]2+, [Co(gly)(en)2]2+, [Co(gly)(tn)2]2+, [Co(sar)(en)2]2+, and Λ- and Δ-[Co(l-ala)(en)2]2+, were determined by the 1H-NMR measurement. The major factors determining the deuteration rate of α-hydrogens in the amino carboxylate chelate are the geometry and charge of the complex, and the nature of the substituent bonded to the chelate ring to be deuterated; the minor factor is the chelate-ring size of the ligands other than amino carboxylate in a complex molecule.
Spin Exchange and Translational Diffusion of Nitroxide Radicals in Micelles. ESR Experiments and Spectra Simulation by Modified Bloch Equations
Authors: Aizawa Masayuki , Komatsu Tsuyoshi , Nakagawa Tsurutaro
Published: July 2006

The dependence of the ESR linewidth of hydrophobic radicals on their concentration in micelles is investigated in two solubilization systems at several temperatures. One system consists of 2,2,6,6-tetramethyl-4-benzoyloxy-1-piperidinyloxyl (BzONO) as a solubilizate and hexadecyltrimethylammonium bromide (CTAB) as a surfactant, and the other, of 2,2,6,6-tetramethyl-4-myristoyloxy-1-piperidinyloxyl (MyONO) and sodium dodecyl sulfate (SDS). The plot of the linewidth against the mole fraction of the radical is not represented by a straight line, as in the previous study. The propriety of the two kinds of models for the solubilization states of radicals which were proposed in the previous paper to explain the unusual shape of these plots is examined by spectra simulation with modified Bloch equations. As these models have proved to be inadequate, a new model taking account of the distribution of the radicals among the micelles is proposed. The simulation based on this model shows a good agreement with the experimental results. The translational diffusion coefficients of radicals in micelles are estimated on the basis of this model. Their values are in the range of (1.5–2.9)×10−11 m2/s.
Temperature Effect on Gas Phase Alkylbenzene Dealkylation
Authors: Perez Giorgio
Published: July 2006

Dealkylation of ethylbenzene, propylbenzene, and isopropylbenzene by radiolytically formed 2H3+ ions has been studied in the gaseous phase as a function of the irradiation temperature. The extent of the reaction, which increases with the temperature follows the order ethylbenzene < propylbenzene < isopropylbenzene. The Arrhenius plots of empirical observed rate constants are linear over the temperature range investigated (40—100 °C) and their slopes correspond to a difference of 12.5 and 10.0 kJ mol−1 between the activation energies for dealkylation of ethylbenzene and isopropylbenzene, and of ethylbenzene and propylbenzene, respectively.
Electrolytic Behavior of Some Divalent Transition Metal Halides in Propylene Carbonate Solution
Authors: Pandey Ram Nagina , Bapat M G
Published: July 2006

The results of conductance measurements of cobalt(II) perchlorate, cobalt(II) chloride, cobalt(II) bromide, and zinc(II) bromide in propylene carbonate at 25 °C are reported. The conductance data for Co(ClO4)2 in PC has been analyzed by Fuoss–Edelson method. The anomalous conductance behavior of CoCl2, CoBr2, and ZnBr2 in PC has been explained on the basis of equilibria MX2   MX+ + X−; MX2 + X−   MX−3; MX+   M2+ + X−; and MX+ + MX−3   (MX2)2. The equilibrium constants of 3MX2   M2+ + 2MX−3; and 2MX2   (MX2)2 equilibria for CoCl2, CoBr2, and ZnBr2 in PC have been calculated in the present investigation. The conductance data of these divalent transition metal halide solutions show the existence of dimers in PC.
Preparation and Characterization of trans- and cis-Anionobis(ethylenediamine)nitrosylruthenium(II) Complexes
Authors: Tomizawa Hiroshi , Miki Eiichi , Mizumachi Kunihiko , Ishimori Tatsujiro
Published: July 2006

In this study trans-[Ru(OH)(en)2NO]2+ (en = ethylenediamine) as well as trans- and cis-[RuX(en)2NO]n+ (X = Cl, Br, I, OAc (acetate), and NCS where n = 2; X = H2O where n = 3) were prepared. The complexes were characterized by IR, NMR, and UV-vis spectra. Although a decrease in the wave number of ν(NO) along with an increase in the π-donor ability of X was observed in the trans isomers, it was not observed in the cis isomers. In the 1H NMR spectra of all the complexes, the resonance signals due to methylene and the amine protons of the en were influenced by the magnetic anisotropy caused by the RuNO group. Two kinds of isomerization reactions were found to be involved in the preparation of the complexes: One was accompanied by a substitution reaction from OH− to X−; the other occurred after the substitution reaction. Moreover, ligand X was substituted immediately by OH− when sodium hydroxide was added to an aqueous solution of the complex; cis to trans isomerization then occurred for the cis isomer.
Stereoselective Preparation and Characterization of [Cr(amino acidato)2(amino acidato-N)(Me2SO)] Complexes
Authors: Oki Hisaya , Kitagawa Yoshiki , Nakata Ryuji
Published: July 2006

New complexes of the type [Cr(AA)2(AA-N)(Me2SO)], where AA stands for l-amino acidato ligands (valinato, isoleucinato, and leucinato) and AA-N represents monodentate l-amino acidato ligands with an amino nitrogen as a donor atom, were prepared by heating mixtures of Cr(NO3)3·9H2O and sodium salts of amino acids in Me2SO. For all the amino acids used, only complexes of the type (+)546-[Cr(AA)2(AA-N)(Me2SO)] were obtained. The presence of a Me2SO molecule as a ligand was shown by the IR spectra of the crystals of the complexes. The bis-type complexes with l-valine and l-isoleucine were converted to (−)546-isomers in MeOH and the resulting products were isolated. All the new complexes were confirmed to have facial configuration, [Cr(O)3(N)3] from their UV-vis absorption spectra, as well as the corresponding tris-type complexes, [Cr(AA)3].
Structure and Properties of (NEt4)2[MoIVO(α,2-toluenedithiolato)2]
Authors: Ueyama Norikazu , Kondo Mitsuru , Oku Hiroyuki , Nakamura Akira
Published: July 2006

A novel oxomolybdenum(IV) complex, (NEt4)2[MoIVO(α,2-toluenedithiolato)2], was synthesized and characterized by visible, Raman and 1H NMR spectroscopies. The complex crystallizes as (NEt4)2[MoIVO(α,2-toluenedithiolato)2]·Et2O in the space group Cc with a = 15.429(3), b = 16.618(2), c = 15.079(3) Å, β = 99.38(2)°, V = 3815(2) Å3, Z = 4, and Dcalcd = 1.315 g cm−3. The structure was solved and refinement based on 5975 reflections converged at R = 0.044and Rw = 0.052. The complex has an apical oxo and transbis(α,2-toluenedithiolato) structure with a tetragonal-pyramidal MoOS4 core. Inertness of the complex to trimethylamine-N-oxide is due to the narrow S(alkane)–Mo–S(alkane) angle preventing from its coordination to the trans position of Mo=O, and/or two strong Mo–S(alkane) bonds preventing a rearrangement from trans dioxo to cis dioxo structure.
Reactions of Diaminosulfoxonium Ylides with Aldehydes. Preparation of Cyclopropyldiaminosulfoxonium Salts
Authors: Okuma Kentaro , Sato Yasunari , Ohta Hiroshi , Yokomori Yoshinobu
Published: July 2006

The reaction of diaminosulfoxonium ylides with aldehydes gave the corresponding cyclopropyldiaminosulfoxonium salts in good yields when 1,8-diazabicyclo[5.4.0.]undec-7-ene (DBU) was used as a base. These ylides reacted with aldehydes to give the corresponding betaines, which resulted in the formation of vinylsulfoxonium salts. The additional ylides reacted with these salts to afford cyclopropylsulfoxonium salts. The reaction of these salts with potassium hydroxide is also described.
Addition of Hydrogen Halides to 1,2-Dialkylpyrrolium Cations
Authors: Sigalov Mark V , Toyota Shinji , Oki Michinori , Trofimov Boris A
Published: July 2006

Although it is believed that addition of an acid to 2-substituted pyrroles produces 5-protonated pyrrolium ions and further reaction is prevented by the stability of the product, this work shows that further addition of hydrogen halides takes place to the pyrrolium ion to produce 2-substituted 4-halo-4,5-dihydro-3H-pyrrolium ions in general. In the case where the 1-alkyl group is a 1-bromoethyl, addition of hydrogen bromide gives one stereoisomer preferentially, of which conformation was determined by NOE experiments to be two C–Br bonds anti with each other, relative stereochemistry being R*and S*. The results are discussed on the thermodynamic stability and/or the kinetic preferences of the products. Generality of the addition of hydrogen bromide to the pyrrolium ion was tested with 1,2-dimethylpyrrole, which gave a kinetically favored isomeric addition product that isomerized to a thermodynamically favored 4-bromo-1,2-dimethyl-4,5-dihydro-3H-pyrrolium bromide on standing.
Electrosynthesis of 5-Chloro- and 5-Azido-4-pyrazole Carboxylic Acid at the Nickel Hydroxide Electrode
Authors: Abdel-Azzem Magdi , Zahran Magdi
Published: July 2006

Pyrazole derivatives are valuable intermediates for drugs and agrochemicals. The literature seems to be almost devoid of suitable methods, from environmental point of view for the preparation of simple pyrazole carboxylic acid derivatives which could be prepared from aldehydes with oxidizing agents such as NaClO4. These reagents are partially toxic and large scale conversions create waste disposal problems. A clean oxidation technique would be the indirect electrochemical oxidation at the nickel hydroxide anode. Until recently there have been few examples of oxidation of heterocyclic aldehydes to the corresponding acids. We represent here an electrochemical method for oxidizing 5-chloro-4-pyrazole carbaldehyde (1) and 5-azido-4-pyrazole carbaldehyde (2) to their corresponding acids (3 and 4) at a nickel hydroxide anode in good yields (80—85%) (Scheme 1).
Tetrahydro-4(1H)-pyrimidinone Ring Formation of Bellenamine, a Biogenic Amine, with Carbonyl Compounds
Authors: Ikeda Yoko , Gomi Shuichi , Naganawa Hiroshi , Ikeda Daishiro , Kondo Shinichi
Published: July 2006

Bellenamine, (R)-3,6-diamino-N-(aminomethyl)hexanamide in a neutral aqueous solution at 37 °C formed a new tetrahydro-4(1H)-pyrimidinone compound, N1,N3-methylenebellenamine by the reaction with self-generated formaldehyde. The structure was elucidated by NMR spectral analyses. Two tetrahydro-4(1H)-pyrimidinone compounds, N1,N3-methylenebellenamine and (R)-6-(3-aminopropyl)tetrahydro-4(1H)-pyrimidinone (tentatively named cyclized bellenamine) were synthesized from bellenamine and d-β-lysinamide, respectively, with an equimolar amount of formalin in good yields. However, formation of a 5-membered ring 4-imidazolidinone compound by the reaction of l-lysinamide with formalin was a very low yield. Reaction of bellenamine with acetaldehyde gave a mixture of four diastereomeric aldol adducts. By the reaction with acetone or diacetone alcohol, two stereoisomeric diacetone adducts, (2R,9aS)- and (2R,9aR)-2-(3-aminopropyl)-8,8,9a-trimethyloctahydro-4H-pyrimido[1,6-a]pyrimidin-4-one, were obtained. Although these adducts were difficult to separate, the (2R,9aR) diastereomer was more stable than the other in acidic aqueous solution.
Lewis Acid-Catalyzed Hetero-Diels–Alder Reactions of Methyl 2-Oxo-3-alkenoates with Alkenes
Authors: Sera Akira , Ohara Meguru , Yamada Hiroaki , Egashira Emiko , Ueda Naohiro , Setsune Jun-ichiro
Published: July 2006

Lewis acid-catalyzed cycloadditions of 4-substituted methyl 2-oxo-3-butenoates and -3-pentenoates with alkenes took place with high regio- and stereoselectivities to afford substituted 6-methoxycarbonyl-3,4-dihydro-2H-pyrans in good to moderate yields. None of the ene products were produced. Similar reactions of methyl 3-phenyl-2-oxo-3-butenoate with alkenes afforded both the corresponding 3,4-dihydro-2H-pyrans and a dimeric cycloadduct of the diene component. The regio- and stereoselectivities of the present inverse-electron-demand cycloadditions indicated that the reactions proceeded through a concerted exo transition state.
Synthesis and Properties of Sterically-Protected 2-Azulenylphosphaethenes. II. 2-(1-Azulenyl)- and 2-(2-Azulenyl)-1-(2,4,6-tri-t-butylphenyl)phosphaethenes
Authors: Ueno Tetsuya , Yasunami Masafumi , Yoshifuji Masaaki
Published: July 2006

Several sterically-protected 2-(1-azulenyl)- and 2-(2-azulenyl)-1-(2,4,6-tri-t-butylphenyl)phosphaethenes were synthesized as kinetically-stabilized crystalline compounds by the phospha-Peterson reaction of the corresponding 1- and 2-formylazulenes with lithium (2,4,6-tri-t-butylphenyl)trimethylsilylphosphide. On the basis of the 31P NMR spectral data, the 1-azulenyl group is believed to be more electron-donating than the 2-azulenyl group. The bathochromic shift of the n–π* transition of the 1-azulenyl derivatives relative to the parent azulene and N-(1-azulenylmethylene)-2,4,6-tri-t-butylaniline indicated that the 2-phosphaethenyl group has an electron-donating nature in contrast to the electron-withdrawing nature of the iminomethyl group.
Synthesis, Properties, and Crystal Structure of a 1,1′-Bis(ethoxycarbonyl)trichotomine Derivative
Authors: Irikawa Hajime , Enomoto Masanori , Shimoda Yoshinori , Atsumi Tadashi , Okumura Yasuaki , Iijima Kinya
Published: July 2006

On an oxidative dimerization in dichloromethane containing diisopropylamine, methyl 1-ethoxycarbonyl2,5,6,11-tetrahydro-3-oxo-3H-indolizino[8,7-b]indole-5-carboxylate gave a trichotomine derivative bearing ethoxycarbonyl groups on C1 and C1′. In the presence of triethylamine, the initially formed trichotomine derivative changed to a blue compound, which had the skeleton of the trichotomine derivative and a =CH–CH= group. The X-ray crystallographic analysis of the trichotomine derivative showed the torsion around the central C–C double bond, and the dihedral angle of the adjacent two five-membered rings was 30.0°. This torsion is due to the steric interactions between the ethoxycarbonyl groups and the amido carbonyl groups, and might explain the difference of the λmax between the trichotomine derivative (690 nm) and the blue compound (633 nm).
Structure Analyses of Nickel(II) Complexes Bound to Copolymersof 2-Acetyl-5-(4-vinylbenzyloxy)phenol, Acrylamide,and 2,2′-Methylenediacrylamide by EXAFS and XANES
Authors: Sato Mitsunobu , Fujii Yuki , Yamamura Takeshi , Yano Shigenobu
Published: July 2006

The coordination of the nickel(II) centers bound to the titled polymers were determined by EXAFS and XANES as being of the octahedral Ni(avp)2(H2O)2 type in both template and non-template polymers.
Tranformations of Gypsum to Calcium Sulfate Hemihydrate andHemihydrate to Gypsum in NaCl Solutions
Authors: Imahashi Masayuki , Miyoshi Towako
Published: July 2006

The transformations of gypsum to calcium sulfate hemihydrate and hemihydrate to gypsum were carried out in NaCl solutions containing a small amount of strontium ions in order to elucidate their mechanisms. The values of the apparent partition coefficient of strontium between solution and solids were followed during the transformations and the gypsum and hemihydrate crystals were observed by SEM. The results showed that the transformations progressed by a dissolution-reprecipitation process.
Photolysis of (2,4,6-Tri-t-butylphenyl)bis(trimethylsilyl)phosphine
Authors: Yoshifuji Masaaki , Shimura Kazuho , Toyota Kozo
Published: July 2006

The photolysis of (2,4,6-tri-t-butylphenyl)bis(trimethylsilyl)phosphine in benzene gave products suggesting homolytic P–C bond cleavage followed by rearrangement and coupling.
Intramolecular Photocyclization in Quinone-Bearing Oligopeptides
Authors: Tamiaki Hitoshi , Hashimoto Masakazu , Maruyama Kazuhiro
Published: July 2006

The photoexcited anthraquinone moiety (AQ) of (N-acetylglycyl)oligopeptide-linked anthraquinones in acetonitrile abstracted intramolecularly the hydrogen in the α-methylene of glycine to give a sole isomeric ring-closure product. Site-selectivity was produced mainly by a difference in the spatial distance between the C=O of AQ and reactive CH2.
A Synthesis of Senecionine, a Representative of Hepatotoxic, Macrocyclic Pyrrolizidine Alkaloids of Retronecine Type
Authors: Niwa Haruki , Sakata Tomoyo , Yamada Kiyoyuki
Published: July 2006

Described is a synthesis of (−)-senecionine, the best-known hepatotoxic, 12-membered pyrrolizidine alkaloid of retronecine type. Integerrinecic acid lactone methyl ester was converted into protected senecic acid, which was regioselectively coupled with (+)-retronecine, achieving the first synthesis of (−)-senecionine.
Elkem Uses Optimization in Redesigning Its Supply Chain
Authors: Ulstein Nina Linn , Christiansen Marielle , Grønhaug Roar , Magnussen Nick , Solomon Marius M.
Published: July 2006

Elkem’s silicon division is the largest supplier of silicon metal and ferrosilicon in the world. With the slowdown in the global economy that started in 2000, the corporation decided to improve the efficiency of its supply chain network and evaluate its product portfolio. To help the division manage this process, we developed a strategic-planning model. This mathematical-programming model addresses decisions pertaining to future plant structure, including possible closures, new plant acquisitions, and investments in production equipment. The silicon division has used the model and its scenario analysis capabilities extensively to obtain important benefits. The company agreed to a restructuring process, which included reopening a closed furnace and investing $17 million in equipment conversion. Overall, as a result of the restructuring plan, Elkem expects a significant and sustained improvement in yearly revenue for the silicon division.
Vehicle Routing and Staffing for Sedan Service
Authors: Günlük Oktay , Kimbrel Tracy , Ladanyi Laszlo , Schieber Baruch , Sorkin Gregory B.
Published: July 2006

We present the optimization component of a decision support system developed for a sedan service provider. The system assists supervisors and dispatchers in scheduling driver shifts and routing the fleet throughout the day to satisfy customer demands within tight time windows. We periodically take a snapshot of the dynamic data and formulate an integer program, which we solve to near optimality using column generation. Although the data snapshot is stale by the time a solution is computed, we are able to solve the integer program quickly enough that the solution can be adopted after minor modifications are made by a fast local-search heuristic. The system described in this paper is currently in use and has improved the provider’s productivity significantly.
A Tabu Search Algorithm for a Routing and Container Loading Problem
Authors: Gendreau Michel , Iori Manuel , Laporte Gilbert , Martello Silvano
Published: July 2006

This article considers a combination of capacitated vehicle routing and three-dimensional loading, with additional constraints frequently encountered in freight transportation. It proposes a tabu search algorithm that iteratively invokes an inner tabu search procedure for the solution of the loading subproblem. The algorithm is experimentally evaluated both on instances adapted from vehicle routing instances from the literature and on new real-world instances.
Efficient Circulation of Railway Rolling Stock
Authors: Alfieri Arianna , Groot Rutger , Kroon Leo , Schrijver Alexander
Published: July 2006

Railway rolling stock is one of the most significant cost components for operators of passenger trains. The efficient circulation of rolling stock is therefore one of the main objectives pursued in practice. This paper focuses on the determination of appropriate numbers of train units of different types together with their efficient circulation on a single line. To utilize the train units on this line in an efficient way, they are coupled to or uncoupled from the trains in certain stations according to the passengers’ seat demand in peak and off-peak hours. Because coupling and uncoupling train units must respect specific rules related to the shunting possibilities in the stations, it is important to take into account the order of the train units in the trains. This aspect strongly increases the complexity of the rolling stock circulation problem. This paper presents a solution approach based on an integer multicommodity flow model with several additional constraints related to the shunting processes at the stations. The approach is applied to a real-life case study based on the timetable of NS Reizigers, the main Dutch operator of passenger trains.
A case series to pilot cognitive behaviour therapy for women with urinary incontinence
Authors: Garley Ailyn , Unwin Jennifer
Published: July 2006

Objective. Psychological factors have been identified with respect to female urinary incontinence. However, there is limited research regarding psychological interventions. The effectiveness of cognitive behaviour therapy (CBT) as a treatment for women with urinary incontinence was investigated.

Design. The study adopted an AB case series design with a follow‐up phase.

Methods. Ten women with urinary incontinence each attended individual sessions. The Hospital anxiety and depression scale (HADS) and Incontinence Quality of Life (I‐QOL) were administered pre‐treatment, post‐treatment, and 3‐months post‐treatment. Participants kept weekly records of bladder functioning. An unstandardized client satisfaction questionnaire was administered at 3‐months post‐treatment.

Results. Anxiety and depression, as measured by the HADS did not show any significant changes. Improvements in incontinence‐related quality of life reached statistical significance at the post‐treatment administration and were maintained at the 3‐months post‐treatment follow‐up. Significant changes in bladder functioning were not apparent until the 3‐month post‐treatment follow‐up. The satisfaction questionnaires suggest that the participants found the intervention of value.

Conclusions. The findings of this study tentatively suggest that incontinence‐related quality of life might be improved by involvement in a CBT intervention. Some modest improvements occurred in bladder functioning. Further research is required to confirm these findings.
Augmenting the theory of planned behaviour with the prototype/willingness model: Predictive validity of actor versus abstainer prototypes for adolescents' health‐protective and health‐risk intentions
Authors: Rivis Amanda , Sheeran Paschal , Armitage Christopher J.
Published: July 2006

Objectives. The present research tested: (a) whether prototype perceptions and descriptive norms from the prototype/willingness model (PWM; Gibbons, Gerrard, Blanton, & Russell, 1998) enhance the prediction of adolescents' intentions to engage in health‐protective and health‐risk behaviours after variables from the theory of planned behaviour (TPB; Ajzen, 1991) and past behaviour have been taken into account and (b) whether images of the type of person who engages in a health behaviour (actor prototypes) and images of the type of person who does not engage in a health behaviour (abstainer prototypes) have equivalent predictive validity.

Design. An experimental design with a single between participants factor (actor versus abstainer prototype) was employed.

Method. Participants in this study were 247 school pupils who completed measures of TPB variables, PWM variables and past behaviour in relation to three health‐protective and three health‐risk behaviours.

Results. Findings indicated that PWM variables accounted for a significant proportion of the variance in behavioural intentions after TPB variables and past behaviour had been taken into account (Mean ΔR2 = .05). Perceived similarity to prototypes was the most consistent additional predictor of intention. Actor and abstainer prototypes exhibited equivalent predictive validity.

Conclusions. The present research suggests that variables from the PWM, especially prototype similarity, enhance the predictive validity of the TPB. The findings also provide new evidence that acquiring the characteristics of both health and risk images may be goals among adolescents and suggest that both healthy and risky prototypes constitute useful cognitive targets for interventions.
Despite its strong transactivation domain, transcription factor FOXM1c is kept almost inactive by two different inhibitory domains
Authors: Wierstra Inken , Alves Jürgen
Published: July 2006

FOXM1c (MPP2) is an activating transcription factor with several nuclear localization signals, a forkhead domain for DNA binding, and a very strong acidic transactivation domain. Despite its very strong transactivation domain, FOXM1c is kept almost inactive by two different independent inhibitory domains, the N-terminus and the central domain. The N-terminus as a specific negative-regulatory domain directly binds to and thus inhibits the transactivation domain completely. However, it lacks any transrepression potential. In contrast, the central domain functions as a strong RB-independent transrepression domain and as an RB-recruiting negative-regulatory domain. The N-terminus alone is sufficient to eliminate transactivation, while the central domain alone represses the transactivation domain only partially. This hierarchy of the two inhibitory domains offers the possibility to activate the almost inactive wild type in two steps in vitro: deletion of the N-terminus results in a strong transactivator, while additional deletion of the central domain in a very strong transactivator. We suggest that the very high potential of the transactivation domain has to be tightly controlled by these two inhibitory domains because FOXM1 stimulates proliferation by promoting G1/S transition, as well as G2/M transition, and because deregulation of such potent activators of proliferation can result in tumorigenesis.