bluuebunny/crossref_metadata_2025 huggingface dataset:
Raman Scattering Study on Coordination Structures of Cu(II)–l-Histidine(1: 2) in Aqueous Solutions
Authors: Itabashi Masao , Itoh Koichi
Published: July 2006

The pH and pD dependences of the Raman spectra of Cu(II)–l-histidine (1:2) and Cu(II)–l-histidine-d3−5 (1:2) were analyzed based on the pH titration data. Several ring vibrations of the imidazolyl group with cationic, neutral and anionic forms, the out-of-plane bending vibration of the bound carboxylate, and the Cu(II)–N stretching vibrations of the bound amino groups are used to study the chelation structures of the species taken by the solutions. From the results it was concluded that MHA2+, the major species below pH 3, assumes a glycine-like chelation structure with an unbound imidazolium cation. The results also indicate that the species MHA2+, which is prominent in the pH region 4.0–4.5, takes a mixed-type structure, in which one histidine molecule coordinates to Cu(II) as a terdentate ligand and another binds as a substituted glycine. MA2, the major species around pH 7, is determined to have the chelation structure in which two nitrogen atoms of the amino groups and two nitrogen atoms of the imidazole rings are bound to the Cu(II) ion in the square-planar trans position and at least one carboxyl group in the axial position.
Restricted SCF and MC-SCF Study of the Σ and II States of the Formyloxyl and Formylaminyl Radicals
Authors: Kikuchi Osamu
Published: July 2006

Open-shell restricted SCF and MC-SCF methods with the semi-empirical MINDO/3 approximation have been applied to the Σ and II states of the formyloxyl and formylaminyl radicals. In the MC-SCF formalism, the π→π* singly- and doubly-excited configurations are included. The optimized molecular structures and spin distributions predicted by the SCF and MC-SCF methods are compared. For the II state of formyloxyl, the restricted SCF method gives a distorted Cs structure as the most stable II structure, while the MC-SCF gives a symmetric C2V structure. The use of the MC wavefunctions is recommended for the evaluation of the molecular and electronic structures of these radicals, in which a doublet instability of the restricted SCF solution is expected to occur.
Hydrogenation Activity and Selectivity of Cobalt Boride and Cobalt Nickel Binary Boride Catalysts
Authors: Nitta Yuriko , Imanaka Toshinobu , Teranishi Shiichiro
Published: July 2006

Co–B catalyst has higher selectivity than Ni–B catalyst for the formation of α,β-unsaturated alcohols from α,β-unsaturated aldehydes and lower selectivity for the formation of olefins from acetylenes. The differences between the two catalysts can be ascribed to the differences in the adsorption strength of reactants on Co and Ni metals. The hydrogenation activities of the Co–Ni–B catalysts vary through a maximum, but the selectivities vary monotonously with nickel content. These features are explained in terms of the surface composition measured by XPS and of the surface area of the catalysts. The enrichment of nickel on the surface and the increase of the surface area are observed for the Co–Ni–B catalysts. Co–B catalysts modified by a small amount of metal salts (Fe, Cr, Cu, etc.) are more effective for the selective hydrogenation of α,β-unsaturated aldehydes than co-precipitated binary boride catalysts.
Catalytic Properties of Iron Oxides. II. Isotopic Exchange of Oxygen, Oxidation of Carbon Monoxide, and Reduction-Oxidation Mechanism
Authors: Sakata Kanji , Ueda Fumio , Misono Makoto , Yoneda Yukio
Published: July 2006

The reactivity and mobility of the lattice oxygen of iron oxide, in particular γ-Fe2O3, has been investigated by 18O-exchange with CO2 and CO oxidation by 18O2. The low mobility of the lattice oxygen is in agreement with the reduction-oxidation mechanism of γ-Fe2O3 bulk, which proceeds by Fe ion migration without diffusion of the lattice oxygen. The rapid diffusion of the Fe ion makes the redox cycles of γ-Fe2O3 easy and explains, together with the cation deficient structure, the high reactivity and selectivity of lattice oxygen. Thus, γ-Fe2O3may be regarded as a new prototype of selective catalyst for allylic oxidation.
Studies on the Polymerization of Acrolein Oxime. XIV. The Structure of 2,4,7-Trimethylperhydroisoxazolo[2,3-a]pyridine-2,7-dicarbaldehyde Dioxime
Authors: Ota Tadatoshi , Masuda Seizo , Kido Masaru
Published: July 2006

The thermal oligomerization of methacrylaldehyde oxime leads preferentially to two 2,4,7-trimethylperhydroisoxazolo[2,3-a]pyridine-2,7-dicarbaldehyde dioximes, which are comformationally isomeric with each other. The crystal structure of the α-form has been determined by means of X-ray diffraction. It is monoclinic, with the space group P21/a. The cell dimensions are a=7.858(3), b=13.186(6), c=17.259(6) Å, β=130.38(3)°, and Z=4. The molecules are linked by OH···O and OH···N intermolecular hydrogen bonds, with the O···O and O···N distances of 2.794(6) and 2.760(5) Å respectively. Since attempts of the crystallization of the β-form have been unsuccessful, the determination of its chemical structure was attempted by means of 13C-NMR spectroscopy and gas chromatography-mass spectrometry. The β-form is, at any rate, different from the α-form.
Restricted Rotation Involving the Tetrahedral Carbon. XXXIV. Stable Rotamers of 9-Arylfluorenes Carrying Oxygen-substituents in the Ortho Position of the Aryl Group
Authors: Nakamura Mikio , Oki Michinori
Published: July 2006

9-(2-Hydroxy-1-naphthyl)fluorene, 9-(2-hydroxy-4,6-dimethylphenyl)fluorene, and their methyl ethers have been prepared. They give stable rotamers, sp and ap, at room temperature, ap forms of the hydroxylic compounds are favored over the sp and contrary is true for the methyl ethers. These results are attributed to the stabilization of the ap form of the hydroxylic compounds due to intramolecular OH···π interaction. Barriers to rotation are ca. 105 kJ mol−1.
Synthetic Studies of Rifamycins. II. Syntheses of Methyl 2,4,6,7-Tetradeoxy-4-C-methyl-3-O-methyl-α-l-arabino-heptopyranosid-6-ulose and Its Derivatives Utilizable in the Construction of the Rifamycin Ansa Chain Portion
Authors: Nakata Masaya , Ikeyama Yutaka , Takao Hideaki , Kinoshita Mitsuhiro
Published: July 2006

3,6-Dideoxy-3-C-methyl-2-O-methyl-d-galactopyranose(12) was prepared in 10 steps from methyl 4,6-O-benzylidene-3-deoxy-3-C-methyl-α-d-altropyranoside. 12 was converted into 4,5-di-O-acetyl-3,6-dideoxy-3-C-methyl-2-O-methyl-d-galactose, which was then condenced in ether with (methoxymethylene)triphenylphosphorane (generated from the phosphonium salt with the dimethylsulfinylmethanide anion in ether) to produce 5,6-di-O-acetyl-2,4,7-trideoxy-4-C-methyl-1,3-di-O-methyl-d-galacto-1-enoheptitol (16). The treatment of 16 with NBS in methanol, followed by the debromination of the resulting 2-bromo aldehyde dimethyl acetal with tributylstannane, deacetylation, and mild methanolysis afforded methyl 2,4,7-trideoxy-4-C-methyl-3-O-methyl-β-d-galacto-heptopyranoside(19), which then provided the title compound 20 upon Jones oxidation. The potential intermediates, the 1-lithio-1-(methyl 2,4-dideoxy-4-C-methyl-3-O-methyl-α-l-arabino-pentopyranos-5-yl)ethene and (E)-2-(methyl 2,4-dideoxy-4-C-methyl-3-O-methyl-α-l-arabino-pentopyranos-5-yl)propenylcopper intermediates, were prepared from 20  via the corresponding alkenyl iodide and (methyl 2,4-dideoxy-4-C-methyl-3-O-methyl-α-l-arabino-pentopyranos-5-yl)ethyne and were demonstrated to condense with benzaldehyde and ethylene oxide respectively.
Catalysis of the Hydrolysis of p-Nitrophenyl 1-Adamantaneacetate by Cyclodextrins
Authors: Komiyama Makoto , Inoue Shohei
Published: July 2006

The cleavage of p-nitrophenyl 1-adamantaneacetate was accelerated by β- and γ-cyclodextrins, which was in contrast with their deceleration of the cleavage of a sterically analogous substrate, p-nitrophenyl 1-adamantanecarboxylate. The presence and absence of a methylene group in these substrates absolutely governed the directions of the rate effects of the cyclodextrins. The specificity, explicitly showing that cyclodextrins are quite good models of enzymes, was attributed to the difference of the structures of the inclusion complexes of cyclodextrins with these substrates.
Formation of Chiral Aggregates of Acylamino Acids in Solutions
Authors: Sakamoto Kazutami , Hatano Masahiro
Published: July 2006

An alcoholic solution of optically active acylamino acid (AAA) was found to show a circular dichroism (CD) band at 212 nm. The CD band should be inherent to the solution system, since AAA and alcohol per se have no absorption band at this wavelength. The CD band intensity decreased on addition of urea and rise in temperature. This is attributed to the formation of chiral aggregate through hydrogen bonds among AAA molecules. Hydrophobic interaction seems to be of minor importance for the formation of the chiral aggregate in alcoholic solution, since the variation of the chain length in the acyl group or addition of myristic acid did not affect the magnitude of profile of the CD band. In aqueous solutions, salts of optically active AAA formed micelles with hydrophobic interactions among the molecules, and only in the case of optically active monosodium salt of N-acylglutamic acid (AGS) showed a CD band at 220 nm resulting from the formation of chiral hydrogen bonds at concentrations above the critical micelle concentration (CMC). This type of chiral aggregation may be caused by the existence of free carboxyl group in the optically active AGS molecule.
The Crystal and Molecular Structure of the Copper(I) Chloride Complex Containing p-Benzoquinone as a Ligand
Authors: Uechi Tetsuo , Yamaguchi Hiroko , Ueda Ikuhiko , Yasukouchi Kazuo
Published: July 2006

The crystal and molecular structure of the red compound, [(NH4)Cu3Cl4(C6H4O2)1.5·H2O], has been determined from 2115 X-ray diffraction data collected on an automated four-circle diffractometer. The crystals are monoclinic, with space group P21/c, and with four formula units in a unit cell of dimensions; a=7.308(5), b=11.593(7), c=18.359(9) Å, and β=90.16(3)°. The structure was solved by direct methods, and block-diagonal leastsquares refinements led to a final discrepancy index, R, of 0.035. The crystal structure is characterized by polymeric, beehive-like layers composed of Cu3Cl4− anions, and centro- and pseudocentrosymmetric p-benzoquinone molecules. Each of the p-benzoquinone molecules acts as a bridging ligand to the two trans Cu3Cl4− anions, with the Cu–C closest distances falling in the range from 2.047(5) to 2.086(5) Å. The NH4+ cations and the water molecules are accommodated by a roughly coplanar arrangement within the tunnel-like holes of the beehives, and the NH4+ cations are joined to the layers by intra- and interlayer hydrogen bonds of the N–H···O type. The Cu3Cl4− has a distorted cubane-type structure with one corner missing, and each Cu atom has a distorted tetrahedral coordination.
The Kinetics of the Polymerization of Silicic Acid
Authors: Shimada Kanichi , Tarutani Toshikazu
Published: July 2006

The process of the polymerization of silicic acid can be divided into three steps: (1) a reaction between monosilicic acids, (2) a reaction between monosilicic and polysilicic acids, and (3) a reaction between polysilicic acids. The rates of the reactions between monomer-monomer, monomer-polymer and polymer-polymer are most rapid at pH values around 9.3, 8.5, and 6.8 respectively. It is concluded that, above about pH 4, the polymerization due to Reactions 1, 2, and 3 proceeds mainly by a reaction between ionized and un-ionized silanol groups.
The Hydrothermal Preparation and Characterization of Platinum Metal Complexes with Ethylenediaminetetraacetic Acid and Propylenediaminetetraacetic Acid
Authors: Saito Masami , Uehiro Takashi , Yoshino Yukichi
Published: July 2006

A new method for hydrothermal syntheses of osmium(III), ruthenium(III), iridium(III), and rhodium(III) complexes with ethylenediaminetetraacetic acid (EDTA) and propylenediaminetetraacetic acid (PDTA) has been developed. More than ten new complexes have been obtained in good yields and characterized by measuring their magnetic susceptibilities, infrared and electronic spectra, and acid-base properties. The stereochemical behavior of the iridium(III) and rhodium(III) complexes has also been described.
Studies on Nucleosides and Nucleotides. VIII. Preparation and Reactions of Triphenylphosphoranediylnucleosides
Authors: Kimura Junji , Yagi Kentaro , Suzuki Hideyuki , Mitsunobu Oyo
Published: July 2006

The reaction of uridine, N4-benzoylcytidine, guanosine, and N6-p-toluoyladenosine with diethyl azodicarboxylate and triphenylphosphine resulted in the formation of the corresponding 2′,3′-O-(triphenylphosphoranediyl)-cyclonucleosides. On the other hand, adenosine afforded, under similar conditions, 3′,5′-O-(triphenylphosphoranediyl)adenosine (19). The difference can be explained in terms of the acidity of base moieties of the nucleosides. The reaction of 2′,3′-O-(triphenylphosphoranediyl)-O2,5′-cyclouridine, N4-benzoyl-2′,3′-O-(triphenylphosphoranediyl)-O2,5′-cyclocytidine, 2′,3′-O-(triphenylphosphoranediyl)-N3,5′-cycloguanosine, or N6-p-toluoyl-2′,3′-O-(triphenylphosphoranediyl)-N3,5′-cycloadenosine with nucleophiles and with electrophiles addorded the corresponding nucleoside derivatives with free 2′- and 3′-hydroxyl groups. Thus the 2′,3′-O-triphenylphosphoranediyl group serves as a protecting group which is readily removed during work-up of the reaction products. 19 reacted with phenyl isocyanate to give 5′-O-phenylcarbamoyladenosine and N6,5′-O-bis(phenylcarbamoyl)adenosine. The reaction of 19 with diphenylketene also afforded acyladenosines with free 2′- and 3′-hydroxyl groups. These results suggested that 3′,5′-O-triphenyl phosphoranediyl group activates the 5′-carbon atom of adenosine.
The Ultraviolet Spectrophotometric Determination of Iron with 2-Thenoyltrifluoroacetone in an Aqueous Solution Containing α-Hydro-ω)-dodecyloxynona(oxyethylene)
Authors: Taketatsu Tomitsugu , Sato Atsuko
Published: July 2006

2-Thenoyltrifluoroacetone is used as a spectrophotometric reagent for the iron(III) ion (0–1.5 (μg ml−1) in a 0.5% α-hydro-ω-dodecyloxynona(oxyethylene) aqueous solution at pH 3.2–3.8. The molar absorptivities of the iron(III) complex at 338, 388, and 500 nm are 4.75×104, 2.30×104, and 4.85×103 1 mol−1 cm−1 respectively. Many diverse ions do not interfere.
Binuclear Metal Complexes. XXXV. Synthesis and Magnetism of Binuclear Copper(II) Complexes with 3-[2-(Dialkylamino)ethylthio]-1-propanols
Authors: Mikuriya Masahiro , Okawa Hisashi , Kida Sigeo
Published: July 2006

Binuclear copper(II) complexes with 3-[2-(dialkylamino)ethylthio]-1-propanols, Cu[R2N(CH2)2S(CH2)3O]X (R=CH3, C2H5; X=NO3−, ClO4−), were prepared and their magnetic properties were investigated in the temperature range 80–300K. The magnetisms were interpreted in terms of the Bleaney-Bowers equation with exchange integral −J=450–495 cm−1, which is much larger than the values (−J=≈250 cm−1) for Cu[R2N(CH2)2NH(CH2)3O]X.
Metal Complexes Coordinating Pyridine Derivatives. I. Preparation and Circular Dichroism Spectra of cis-α Isomers of [(S)-N,N′-Bis(2-pyridylmethyl)propylenediamine]dihalogenochromium(III) and -cobalt(III) Complexes
Authors: Yamamoto Yukihiro , Shimura Yoichi
Published: July 2006

Several chromium(III) and cobalt(III) complexes with (S)-N,N′-bis(2-pyridylmethyl)propylenediamine (S-picpn) were prepared and their structures assigned. The [CoCl2(S-picpn)]+ complex was reassigned to have cis-α configuration. The Δ and Λ diastereomers of [CrX2(S-picpn)]+ of cis-α. configuration were obtained (X=Cl− and Br−) and their absorption and circular dichroism spectra were discussed.
Benzo-15-crown-5–Aluminium Chloride Complexes of Unusual Stability
Authors: Wada Fumio , Matsuda Tsutomu
Published: July 2006

Among twelve crown ethers of 12, 15, 18, and 21 rings only benzo-15-crown-5 and those with an electron-releasing substituent formed the complexes with aluminium chloride which were stable in methanol.
Solvent Effect on the Adsorption of 1-Octadecanol at Oil/Water Interface
Authors: Ikenaga Takayuki , Matubayasi Norihiro , Aratono Makoto , Motomura Kinsi , Matuura Ryohei
Published: July 2006

In order to study the effect of solvent on the adsorption at interfaces, interfacial tension was measured as a function of temperature and compositon for the systems of water and solutions of 1-octadecanol in cyclohexane, cyclohexene, mesitylene, toluene, and benzene. The interfacial density of 1-octadecanol and the entropy and energy of interface formation were calculated thermodynamically. It was found that cyclohexane causes a significant adsorption of 1-octadecanol and marked decreases in the entropy and energy changes, giving rise to phase transition from expanded to condensed film, while benzene, toluene, and mesitylene cause only a slight adsorption and small decrease in thermodynamic quantities. Cyclohexene was found to give rise to an intermediate adsorptive behavior of 1-octadecanol. The results were interpreted in terms of the mutual solubility between water and solvents and that of 1-octadecanol in the solvents.
Effect of Pressure on Proton Jumps in Methanol at 25 °C
Authors: Nakahara Masaru , Kumo-oka Yoshio , Osugi Jiro
Published: July 2006

Conductivities of HCl and KCl in methanol containing traces (0.12 to 0.40 mol%) of water have been measured in the concentration range of ≈0.4 to ≈5 mmol dm−3 at 25 °C up to 2000 kg cm−2. The limiting equivalent conductance (Λ°) for HCl and KCl decreased with increasing pressure. The excess proton conductance due to the proton-jump mechanism has been measured by Λ°(HCl)−Λ°(KCl) and found to increase with increasing pressure in nearly and absolutely pure methanol. The acceleration of proton jumps by pressure indicates that the rotation of methanol molecules about the longer molecular axis becomes faster at higher pressure. This anomaly is attributed to distortion with pressure of hydrogen bonds in methanol and to an increase in the repulsive field exerted by the proton on the molecule to rotate.
A Conductance Study of Alkali Metal Ion-15-Crown-5, 18-Crown-6, and Dibenzo-24-crown-8 Complexes in Propylene Carbonate
Authors: Takeda Yasuyuki , Yano Hisao , Ishibashi Masayuki , Isozumi Hiroshi
Published: July 2006

The formation constants, KML+, for 1:1 complexes of 15-crown-5 (15C5), 18-crown-6 (18C6), and dibenzo-24-crown-8 (DB24G8) with alkali metal ions and the limiting ionic molar conductivities, λ°, of the complexed cations in propylene carbonate have been determined at 25 °C conductometrically. The KML+ value series about the same alkali metal ion among the crown ethers are given in the order 18C6>>DB24C8>15C5. The KML+ sequences of the alkali metal ions with 15C5, 18C6, and DB24C8 are Li+>Na+>K+>Rb+>Cs+, K+>Na+>Rb+>>Cs+, and Na+>K+>Rb+≥Cs+, respectively. The indication is that the ability of the alkali metal ions to form complexes with the three crown ethers is not always affected primarily by the relative sizes of the alkali metal ions and the crown ether cavity. In each case of 18C6 and DB24C8 the λ° values of the alkali metal ions are nearly equal, while in the case of 15C5 there are considerably differences, suggesting that in the former case the charge of the alkali metal ion trapped in the crown ether cavity is effectively shielded. This is not true in the latter case.
The Crystal Structures of the α and β Forms of Dl-Methionine
Authors: Taniguchi Tomohiko , Takaki Yoshito , Sakurai Kiichi
Published: July 2006

The crystal structures of the α and β forms of Dl-methionine have been refined by block-diagonal least-squares calculations using three-dimensional X-ray data to R=0.118 and 0.088 respectively. The structures of both the forms are essentially the same as those previously reported by Mathieson (Acta Crystallogr., 5, 332 (1952)).
Preparation and Solid-phase Thermal Reactions of Hexaamminechromium(III) Amino Polycarboxylates under Quasi-isothermal and -isobaric Conditions
Authors: Tsuchiya Ryokichi , Uehara Akira , Kobayashi Kazuhiko
Published: July 2006

The following hexaamminechromium(III) amino polycarboxylates were prepared: [Cr(NH3)6]Naedta·3H2O, [Cr(NH3)6]Napdta·6H2O, [Cr(NH3)6]HK3Cl(nta)2·2H2O and [Cr(NH3)6]KCl(nta)·2H2O, where edta, pdta and nta denote ethylenediaminetetraacetate, propylenediaminetetraacetate and nitrilotriacetate ions, respectively. Their thermal reactions in the solid-phase were examined by Q-derivatography (quasi-closed system; quasi-isothermal and -isobaric conditions) and D-derivatography (open system; dynamic conditions). The reactions in open system were too complicated to yield uniform intermediates. On the other hand, each reaction step in the quasi-closed system was definite and reproducible, the products obtained in each reaction step being remarkably pure.
Synthesis and Spectroscopic Investigations of Some Binuclear Organotin(IV) Complexes of Malonobis(salicylidenehydrazide) and Crystal Structure Study of [(C2H5)2Sn]2[OC6H4CH=NNCO]2CH2
Authors: Degaonkar Manju P , Puranik Vedavati G , Tavale Sudam S , Gopinathan Sarada , Gopinathan Changaramponnath
Published: July 2006

The Schiff base, [HOC6H4CH=NNHCO]2CH2 [H4L], derived from the condensation of salicylaldehyde and malonodihydrazide, reacted with organotin chlorides to yield binuclear complexes of the type R2Sn[L]SnR2, where R=CH3–, C2H5–, C4H9–, C6H5–, CH3CO2CH2CH2–, and C6H5CH2–. The complexes were characterized and the structure assigned on the basis of their elemental analysis, IR, 1H, 13C, 119Sn NMR spectral, and X-ray crystallographic data. In these complexes, the ligand functions as a flexibly bridging tetrabasic hexadentate moiety binding two tin atoms through ONO donor atoms and both tin atoms are in trigonal bipyramidal environment.

A single crystal diffraction study of the complex, [(C2H5)2Sn]2(OC6H4CH=NNCO)2CH2, confirms the structure to be binuclear. The crystals are monoclinic, space group I2/a with a = 12.312(2), b = 11.526(2), c = 18.858(2) Å, β = 94.69(2)°, volume = 2667.1(7) Å3, Z = 4, Dc = 1.718 g cm−3. The final discrepancy factors are R = 0.042, Rw = 0.055 for 1698 observed reflections. Half of the molecule is bridged to the other half by two fold symmetry via C(13) atom. The tin atom has distorted trigonal bipyramidal coordination with two oxygens occupying axial positions while two ethyl groups and azomethine nitrogen occupy the equatorial positions. The two ethyl groups coordinated to tin are cis to each other.
SO-Photoextrusion of 7-Thiabicyclo[2.2.1]hept-2-ene 7-Oxides
Authors: Thiemann Carolin , Thiemann Thies , Li YuanQiang , Sawada Tsuyoshi , Nagano Yoshiaki , Tashiro Masashi
Published: July 2006

The photoextrusion of the SO-bridge of 7-thiabicyclo[2.2.1]hept-2-ene 7-oxides is discussed. An analysis of all the major by-products in the exemplary case of the photo reaction of 3a is given. The existence of intermediate dienes 4 has been established. Data on a comparative photoextrusion of an epithio-bridge of 7-thiabicyclo[2.2.1]-hept-2-ene (6) are provided.
Quinolinium Fluorochromate (QFC), C9H7NH[CrO3F]: An Improved Cr(VI)-Oxidant for Organic Substrates
Authors: Chaudhuri Mihir K , Chettri Shiv K , Lyndem Synjukta , Paul Pradip C , Srinivas Pendyala
Published: July 2006

Yellow-orange crystalline quinolinium fluorochromate (QFC) is easily prepared in a nearly quantitative yield by the interaction of quinoline with CrO3 and hydrofluoric acid in 1 : 1.5 : 1 molar ratio. The reagent is stable. Compared with pyridinium fluorochromate (PFC), the new reagent is more soluble in organic solvents and less acidic. QFC in CH2Cl2 readily oxidizes primary, secondary, and allylic alcohols to the corresponding carbonyls, benzoin to benzil, and anthracene and phenanthrene to anthraquinone and 9,10-phenanthrenequinone, respectively. Oxidations work well also in a variety of sensitive environments, e.g. isopropylidene functionality and trimethylsilyl ethers. Organic sulfides are transformed to sulfoxides at room temperature. The facile oxidation of triphenylphosphine to triphenylphosphine oxide by QFC in CH2Cl2 or CH3CN provides a clear evidence for an oxygen-transfer reaction. The reduced product of QFC, isolated after such reactions, has been ascertained to be C9H7NH[CrO2F], a chromium(IV) species. The advantages of QFC have been highlighted.
Halogenation Using N-Halogenocompounds. II. Acid Catalyzed Bromination of Aromatic Compounds with 1,3-Dibromo-5,5-dimethylhydantoin
Authors: Eguchi Hisao , Kawaguchi Hideichiro , Yoshinaga Sachiyo , Nishida Akiko , Nishiguchi Takeshi , Fujisaki Shizuo
Published: July 2006

Ring bromination of aromatic compounds using 1,3-dibromo-5,5-dimethylhydantoin in dichloromethane is promoted by the addition of strong acids. Both organic and inorganic acids whose pKa values are lower than -2 showed the promoting effect. This acid-catalyzed bromination is both practical and effective, even for aromatics having electron-withdrawing substituents.
Catalytic Polymerization of Aniline and Its Derivatives by Using Copper(II) Salts and Oxygen. New Type of Polyaniline with Branched Structure
Authors: Toshima Naoki , Yan Hu , Ishiwatari Mariko
Published: July 2006

The catalytic polymerization of aniline and its derivatives was performed by stirring the solution of the corresponding monomer and copper(II) salts (50/5, mmol/mmol) in acetonitrile and water (1/1, v/v) under oxygen at room temperature for 24 h. Among copper salts, CuBr2 and CuCl2 are more active than the others. In each case the copper salts do not work as a stoichiometrical oxidant but work as a catalyst, which can be proved on the basis of turn-over-frequency. The polymers isolated were characteristic of polyaniline with an Emeraldine structure, although a small amount of branched structures were by-produced by an addition reaction at ortho-position. Thus, heat treatment of the polymer at 284 °C results in partial decomposition to produce the stable polymer and aniline. Although the resulting polymer had an Emeraldine type structure, a strong doping effect on its electroconductivity was not observed, probably because of the amorphous morphology. The UV-vis spectra of the reaction solution have suggested that the catalytic polymerization of aniline proceeds through the formation of the copper(II) complex of aniline.
Preparation and Characterization of T-Cage-Type S-Bridged RhIIICdII Polynuclear Complexes with 2-Aminoethanethiolate
Authors: Konno Takumi , Kageyama Yuichi , Okamoto Ken-ichi
Published: July 2006

The reaction of fac(S)-[Rh(aet)3] with Cd(NO3)2 in water gave a T-cage-type S-bridged RhIII4CdII3 complex with a “defective” [Cd3HO]5+ core, [{Rh(aet)3}4Cd3HO](NO3)5 (1). The corresponding T-cage-type RhIII4CdII4 complex with a “complete” [Cd4O]6+ core, [{Rh(aet)3}4Cd4O](NO3)6 (2), was formed by the reaction of fac(S)-[Rh(aet)3] with a mixture of Cd(NO3)2 and CdO in water. These complexes were characterized by a combination of X-ray diffraction and spectroscopic methods.
Preconcentration of Indium(III) by Coprecipitation with Gallium Phosphate for Electrothermal Atomization Atomic Absorption Spectrometry
Authors: Kagaya Shigehiro , Ueda Joichi
Published: July 2006

Gallium phosphate coprecipitates quantitatively 0.5—7.5 μg of indium(III) from 100—500 cm3 of water at pH 2.5—6.0 and from the same volume of sea water at pH 3.5—6.0. The detection limit (signal/noise = 2) is 0.3 ng cm−3 of indium(III) in 500 cm3 of the initial sample solution.
CODELCO, Chile Programs Its Copper-Smelting Operations
Authors: Pradenas Lorena , Zúñiga Jorge , Parada Víctor
Published: July 2006

CODELCO’s Chuquicamata Copper Smelter, located in Chile, must meet an environmental standard established in 2002 that limits the sulfur emissions from the copper-production process. This regulation placed new restrictions on the production process, and consequently the heuristic criteria based on years of operator experience no longer resulted in high production levels. We developed a model to maximize production while respecting metallurgic, operational, environmental, and other restrictions. We created two methods of planning daily activities for the plant. We developed a client-server tool that displays optimization results graphically and numerically based on data on operational conditions recorded in real time and data input manually. The smelter has used the system since March 2003. We found an increase in the quantity of copper concentrate processed of 25.4 percent.
Niver Lines: A System-Dynamics Approach to Tanker Freight Modeling
Authors: Dikos George , Marcus Henry S. , Papadatos Martsin Panagiotis , Papakonstantinou Vassilis
Published: July 2006

Managers can improve their investment decisions in a cyclical market, such as the tanker market, by using system-dynamics models. We developed and implemented a system-dynamics model for the tanker market for Niver Lines. We combine entry, exit, and lay-up decisions, and determine the flow of transportation supply. Then, we compare supply and demand and calibrate the system. We derived time-charter rates from the interaction of supply and demand using historical data from 1980 through 2002. Our results reveal the key factors that affect tanker rates and unforeseen dynamics. The model is a powerful tool for modeling the impact of changes in various factors on time-charter rates.
Incentive Schemes for Attended Home Delivery Services
Authors: Campbell Ann Melissa , Savelsbergh Martin
Published: July 2006

Many companies with consumer direct service models, especially grocery delivery services, have found that home delivery poses an enormous logistical challenge because of the unpredictability of demand coupled with strict delivery windows and low profit margin products. In this paper, we examine the use of incentives to influence consumer behavior to reduce delivery costs. We propose optimization models for two forms of incentives and demonstrate their value and impact through simulation studies. We conclude with a presentation of insights resulting from our efforts.
The development of insomnia within the first year: A focus on worry
Authors: Jansson Markus , Linton Steven J.
Published: July 2006

Objectives: The aim of this investigation was to study the relationships between sleep‐related worry and subjective sleep perception as a function of stage of chronicity.

Design: A cross‐sectional study consisting of 136 individuals with a short history of insomnia was used.

Methods: The 136 participants were grouped to form two different levels of chronicity based on their duration of insomnia: short (3–7 months; n = 69) and long (>7–12 months; n = 67). Two domains of sleep‐related worry (sleeplessness and health) were used as predictors of subjective sleep perception (sleep onset latency, time awake after sleep onset, and total sleep time).

Results: The association between worry for sleeplessness and subjective sleep perception was significantly different across the stages of chronicity. In the group with a short duration of insomnia, worry for sleeplessness was not related to subjective sleep perception. Worry for sleeplessness was however a significant predictor of subjective sleep perception in the group with a long duration of insomnia (unique variance: 33% on sleep onset latency, 19% on time awake after sleep onset, and 13% on total sleep time). Even if marked differences were observed between the two groups, worry for health was not significantly different across stages of chronicity on subjective sleep perception.

Conclusions: This suggests that the role of sleep‐related worry to subjective sleep perception may increase over time. Given that worry was a mechanism with an increasingly stronger impact over time, this supports the idea that worry is a potential mechanism related to the development of insomnia.
Preanalytical variability: the dark side of the moon in laboratory testing / Präanalytische Variabilität: die Schattenseite klinischer Laboruntersuchungen
Authors: Lippi Giuseppe , Guidi Gian Cesare , Mattiuzzi Camilla , Plebani Mario
Published: July 2006

Remarkable advances in instrument technology, automation and computer science have greatly simplified many aspects of previously tedious tasks in laboratory diagnostics, creating a greater volume of routine work, and significantly improving the quality of results of laboratory testing. Following the development and successful implementation of high-quality analytical standards, analytical errors are no longer the main factor influencing the reliability and clinical utilization of laboratory diagnostics. Therefore, additional sources of variation in the entire laboratory testing process should become the focus for further and necessary quality improvements. Errors occurring within the extra-analytical phases are still the prevailing source of concern. Accordingly, lack of standardized procedures for sample collection, including patient preparation, specimen acquisition, handling and storage, account for up to 93% of the errors currently encountered within the entire diagnostic process. The profound awareness that complete elimination of laboratory testing errors is unrealistic, especially those relating to extra-analytical phases that are harder to control, highlights the importance of good laboratory practice and compliance with the new accreditation standards, which encompass the adoption of suitable strategies for error prevention, tracking and reduction, including process redesign, the use of extra-analytical specifications and improved communication among caregivers.
Estimating Sockeye Salmon Smolt Flux and Abundance with Side-Looking Sonar
Authors: Mueller Anna-Maria , Degan Don J. , Kieser Robert , Mulligan Tim
Published: July 2006

Abundance estimates of out-migrating sockeye salmon Oncorhynchus nerka smolts are used to prepare preseason forecasts of adult returns and to set escapement goals. Here we describe a method for estimating smolt flux and abundance that uses side-looking sonar. This method more efficiently covers the river cross section and is logistically easier to deploy than up-looking sonar systems. To account for the skewed vertical distribution of smolts, we used a recently developed model for correcting echo integration bias associated with nonuniform target distribution. The correction is based on adjusting the integrated beam pattern for a given distribution of targets relative to the transverse cross section of the beam. We compared the results with estimates derived from video data and modeled the effect of three vertical distributions of smolts and three transducer pitch angles. The model estimated correction factors that ranged from 0.6 to 2.6. Correction factors were greater than 1 (which indicates negative bias in conventional echo integration) for smolt distributions skewed toward the edge of the beam and less than 1 (which indicates positive bias in conventional echo integration) for distributions skewed towards the center of the beam. For the scenarios modeled, the effect of the transducer pitch angle was small between the horizontal and −0.6° but increased nonlinearly as the angle increased. We conclude that, in the given application and at shallow transducer pitch angles, the bias in conventional echo integration is small and predictable enough to be corrected.
A Comparison of Methods for Sampling round Goby in Rocky Littoral Areas
Authors: Diana Christine M. , Jonas Jory L. , Claramunt Randall M. , Fitzsimons John D. , Marsden J. Ellen
Published: July 2006

Invasion of the round goby Neogobius melanostomus in the Great Lakes has prompted investigation into qualitative and quantitative sampling strategies. Design of an optimal sampling strategy to monitor expanding round goby populations should consider the accuracy, precision, and associated costs of gears and their deployment strategies. The goal of this study was to compare three common, low-cost, readily available gear types used to sample round goby (gill nets, minnow traps, and trotlines) in terms of catch rates, size selectivity, and bycatch. During fall assessments, baited minnow traps were the most effective at collecting round goby, followed by trotlines and monofilament gill nets. Minnow traps were more selective of small round goby, while trotlines and gill nets were more selective of larger individuals. Bycatch associated with minnow traps and trotlines was lower than that associated with gill nets. Seasonal variation in gear effectiveness was apparent: during spring, gill nets caught 216 round goby and minnow traps caught none, while during the fall only 11 round goby were captured in gill nets and 868 were captured in minnow traps. During summer assessments, diel movements were evident, as gill nets set during periods of low or no light captured more round goby than those set during the day. The cost-benefit analysis indicated that passive gears had lower scores (i.e., were more cost-effective) than active gears. The financial cost of the three gears indicated that the cost per round goby varied among gears and seasons. Our results demonstrated that baited minnow traps set overnight were the most efficient, easily deployed, cost-effective gear and exhibited less variable catch rates during late summer and fall than either gill nets or trotlines.
A Comparison of Methods for Sampling Fish Diversity in Shallow Offshore Waters of Large Rivers
Authors: Lapointe Nicolas W. R. , Corkum Lynda D. , Mandrak Nicholas E.
Published: July 2006

Few studies of fish assemblages have been conducted in large rivers owing to the difficulties of sampling such complex systems. We evaluated the effectiveness of six different gear types (seine nets, boat electrofishers, hoop nets, Windermere traps, trap nets, and minnow traps) in sampling the fish assemblage at 30 sites in the shallow offshore waters of the middle Detroit River in July and August 2003. A total of 2,449 fish representing 38 species in 15 families were captured by seining (1,293 fish, 29 species), boat electrofishing (398 fish, 23 species), hoop nets (524 fish, 26 species), and Windermere traps (234 fish, 14 species). Trap nets and minnow traps were not effective in sampling offshore littoral sites. Significantly higher fish species richness and abundance were obtained and more unique species were captured by seine nets than by any other gear type. When effort is constant, the highest richness and abundance are obtained by seine nets. Windermere traps produced significantly lower abundance and richness than all other gear types, but proportionally more benthic species. Total species accumulation rates were not markedly reduced when Windermere trap data were excluded. Use of additional Windermere traps at each site could increase abundance, but samples taken by Windermere traps had the lowest rarefied richness among gear types at any level of abundance. Nonmetric multidimensional scaling showed that seine-net catches, which were dominated by midwater schooling species (brook silverside Labidesthes sicculus, emerald shiner Notropis atherinoides, and mimic shiner N. volucellus), were most dissimilar from Windermere trap catches, which were dominated by centrarchids. Seine nets were the most effective gear for sampling offshore waters.
Effects of Suspended Sediment on the Escape Behavior and Cover‐Seeking Response of Juvenile Chinook Salmon in Freshwater
Authors: Korstrom Jillian S. , Birtwell Ian K.
Published: July 2006

In laboratory experiments, we quantified the innate adaptive escape behavior and cover‐seeking response of juvenile Chinook salmon Oncorhynchus tshawytscha exposed to elevated levels of turbidity and suspended sediments for a duration predicted to elicit sublethal effects. Treatment fish were held for 48 h at 10°C in a sediment slurry (30,000 mg/L; 50,000 nephelometric turbidity units [NTU]) made up of about 46% clay (<0.002 mm), 46% silt (<0.053 and >0.002 mm), and 8% fine sand (<2.00 and >0.053 mm). The behavioral response of individual control and treatment fish was then examined in clear water (1.9 NTU) through the use of a performance challenge test. Challenge tests can determine the sublethal effects of contaminants on an organism's ability to adapt and survive in its environment. The behavioral avoidance response was characterized as the amount of time in which individual fish swam out of the field of view and sought cover. The tendency of fish to escape to shelter, the time to swim from an open, well‐lit space into shade beneath overhead cover, and the trajectory of each escape response were recorded by a video camera coupled to a digital recorder. The ability of sediment‐exposed Chinook salmon to escape to cover was impaired relative to that of control fish: There was a significant increase in stuporous behavior and a significant reduction in cover‐seeking response in the sediment‐exposed fish. Treatment fish were slower to seek cover from intense light and displayed erratic swimming behavior. These results suggest that even a relatively brief (48‐h) exposure to elevated levels of suspended sediment could indirectly jeopardize survival in the wild, as such overt performance and behavioral changes would probably render juvenile Chinook salmon more conspicuous and therefore more susceptible to avian and aquatic predators.
Growth Modulation Alters the Incidence of Early Male Maturation and Physiological Development of Hatchery‐Reared Spring Chinook Salmon: A Comparison with Wild Fish
Authors: Larsen Donald A. , Beckman Brian R. , Strom Charles R. , Parkins Paul J. , Cooper Kathleen A. , Fast David E. , Dickhoff Walton W.
Published: July 2006

Previous studies conducted at the Cle Elum Spring Chinook Salmon Supplementation Hatchery in Washington State demonstrated that 37–49% of the male Chinook salmon Oncorhynchus tshawytscha released from this facility in its first years of operation precociously matured at age 2 rather than the more typical age 4. We examined the effects of altering seasonal growth rate on the incidence of age‐2 male maturation in an experimental subset of that population and compared their physiological development (size, growth rate, condition factor, whole‐body lipid, gill Na+,K+‐ATPase activity, and plasma insulin‐like growth factor‐I [IGF‐I]) with that of both hatchery (production) and wild fish. Altering summer and autumn rations resulted in four growth trajectories with the following size and precocious male maturation rates: The high summer—high autumn growth trajectory produced fish averaging 25 g and 69% precocious maturation; the high summer—low autumn trajectory yielded fish that averaged 18 g and exhibited 58% precocious maturation; the low summer—high autumn trajectory produced 18‐g fish with 51% precocious maturation; and the low summer—low autumn trajectory yielded fish averaging 16 g and 42% precocious maturation. Production fish averaged 22 g and exhibited a 53% precocious maturation rate. The high summer growth treatments and production fish were largest among all groups and had higher plasma IGF‐I, adiposity levels, and precocious male maturation rates than did the low summer growth treatments. Wild fish were significantly smaller and leaner and had much lower plasma IGF‐I levels than all other groups. Gill Na+,K+‐ATPase activity was not different between groups, suggesting that there was no differential effect on smoltification. Growth modulation reduced the precocious male maturation rate by 39% among experimental treatments and by 21% between production fish and the low—low treatment. However, the maturation rate and adiposity of hatchery fish differed markedly from those of wild fish, suggesting that more dramatic alterations of rearing regime may be required to further reduce the prevalence of this phenotype in cultured fish.
Reduced Streamflow Lowers Dry‐Season Growth of Rainbow Trout in a Small Stream
Authors: Harvey Bret C. , Nakamoto Rodney J. , White Jason L.
Published: July 2006

A wide variety of resource management activities can affect surface discharge in small streams. Often, the effects of variation in streamflow on fish survival and growth can be difficult to estimate because of possible confounding with the effects of other variables, such as water temperature and fish density. We measured the effect of streamflow on survival and growth of rainbow trout Oncorhynchus mykiss in a small stream in northwestern California by manipulating the flow entering four of eight enclosed stream sections (9.0–15.3 m long) containing one pool and 2.5–4.0 m of upstream riffle habitat. In the four manipulated experimental units, we reduced inflow by 75–80% over a 6‐week period in summer 2003. Flow diversion substantially decreased water velocity in riffle–pool transition areas but did not strongly affect habitat volume or water temperature. Fish in control units grew about 8.5 times as much as those in units with reduced streamflow; however, discharge manipulation did not affect survival, which exceeded 90% in both treatments. The input of invertebrate drift to pools within control units greatly exceeded the input into units with reduced streamflow; the concentrations of drifting invertebrates differed to a lesser extent between control and manipulated units. Managers concerned about salmonid populations in small streams should consider dry‐season streamflow to be a key variable affecting fish growth.
Thermal decomposition of ammonia. N2H4-an intermediate reaction product
Authors: Dirtu Daniela , Odochian Lucia , Pui Aurel , Humelnicu Ionel
Published: July 2006

The paper reports the thermal decomposition of ammonia under dynamic conditions at 800°C in a quartz reactor. Its purpose is to confirm the homogeneous-heterogeneous degenerated branched chain mechanism established in previous studies, which assume the formation of N2H4 as a molecular intermediate; this paper identifies hydrazine as a product of thermal decomposition using FT-IR and UV-VIS spectroscopies.
Practical Aspects of Radioligand Binding
Authors: McKinney Michael , Raddatz Rita
Published: July 2006

Radioligand binding has been used for many years to identify new binding sites, characterize receptors, and identify novel ligands. Although various techniques have been developed to improve the efficiency of preparing the biological source of the receptors and for detecting bound radioligand, the principles of the assays remain the same. This unit reviews theory and provides examples of the parameters that can be calculated from radioligand binding data to characterize ligand‐receptor interactions. The important aspects of assay development and validation that allow meaningful interpretation are discussed. The selection of a radioligand, buffer and other assay components is critical to developing a useful binding assay. The nature of the binding interaction can also be probed by varying assay conditions.
Head‐Out Plethysmography in Safety Pharmacology Assessment
Authors: Renninger Jonathan P.
Published: July 2006

The importance of the ability to accurately evaluate respiratory function in animals has been underscored by the classification of the respiratory system as a vital organ system by regulatory agencies in the United States, the European Union, and Japan. A comprehensive assessment of respiratory function should include an evaluation of ventilatory function, including rate and volume measurements, overall pulmonary ventilation (i.e., minute volume), and lung function, including resistance to lung airflow. A volume‐displacement, head‐out, plethysmograph chamber is widely considered the most accurate method for measuring respiratory flows and volumes in small animals because it allows direct assessment of both volume and rate as well as resistance to lung airflow, a predictor of airway constriction or obstruction. Direct assessment of airway resistance is important because mild to moderate increases are generally not detected as changes in ventilatory patterns. This unit describes a method for evaluating ventilatory and lung function in conscious rats.
Synthesis of Amino Acid Phosphoramidate Monoesters via H‐Phosphonate Intermediates
Authors: Choy Cindy J. , Drontle Dan P. , Wagner Carston R.
Published: July 2006

Diphenyl phosphite and bis(N,N‐diisopropylamino)chlorophosphine are used as phosphitylating reagents to generate H‐phosphonate monoesters. These H‐phosphonate intermediates are subsequently oxidized with iodine to generate the 5′‐nucleoside amino acid phosphoramidates.