bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Monoaza Crown Ethers from N,N-Di[oligo(oxyalkylene)]amines and Oligoethylene Glycol Di(p-toluenesulfonates) or Corresponding Dichlorides
Authors: Maeda Hirokazu , Furuyoshi Shigeo , Nakatsuji Yohji , Okahara Mitsuo 
Published: July 2006

Abstract
Monoaza crown ethers were prepared in satisfactory yields by the one-step reaction between diethanolamine or N,N-di[oligo(oxyethylene)]amines and oligoethylene glycol di(p-toluenesulfonates) or corresponding dichlorides in t-butyl alcohol/dioxane in the presence of sodium or potassium t-butoxide. The reaction conditions in the preparation of monoaza 15- and 18-crown ethers were studied. Various monoaza crown ethers having substituents were also prepared and their properties were investigated.
Mass Spectra of Butyl Esters and N-Trifluoroacetyl Butyl Esters of Some Iminodicarboxylic Acids upon Electron Impact
Authors: Kawashiro Katsuhiro , Morimoto Shiro , Yoshida Hideyuki 
Published: July 2006

Abstract
Mass spectra (electron impact at 20 eV) of butyl esters and N-trifluoroacetyl (TFA) butyl esters of some iminodicarboxylic acids (IDCAs) were determined by gas chromatography-mass spectrometry. The IDCAs included iminodiacetic acid (1), 2-(carboxymethylamino)propionic acid (2), 3-(carboxymethylamino)propionic acid (3), 2,2′-iminodipropionic acid (4), 2,3′-iminodipropionic acid (5), 3,3′-iminodipropionic acid (6), N-methyliminodiacetic acid (7), and nitrilotriacetic acid (8). The mass spectra of the butyl ester derivatives are simple, exhibiting the corresponding molecular (M+) ions with the exception of 5. The α,α′-IDCAs (1, 2, 4, 7, and 8) are characterized by M+, M −101 (COOC4H9) (base peak), and M −157 (COOC4H9+C4H8) ions. The β,β′-IDCA (6) is characterized by a more complex spectrum with M+, M −73 (OC4H9), M −115 (CH2COOC4H9) (base peak), M −129 (OC4H9+C4H9), and M −171 (CH2COOC4H9+C4H9) ions. The α,β′-IDCAs (3 and 5) in general show spectra in which both ions characteristic of α,α′- and β,β′-IDCAs are observed. The addition of TFA to the imino nitrogens of 1–6 increases complexity of the resulting spectra. In these instances, although M+ ions are usually present, neither M −101 nor M −115 ions are base peaks. The fragmentation pathways of these two volatile derivatives of the IDCAs upon electron impact are discussed.
Photoresponsive Crown Ethers. 12. Photocontrol of Metal Ion Complexation with Thiacrown Ethers
Authors: Shinkai Seiji , Honda Yoshihiro , Ueda Kaori , Manabe Osamu 
Published: July 2006

Abstract
Thiacrown ethers with a photofunctional azolinkage were synthesized to control their binding ability by an on-off light switch: They are the N2S4 crowns capped with 2,2′-azopyridine (1) or azobenzene (2). The cis-trans isomerism occurred reversibly by photoirradiation. The binding ability, evaluated by solvent extraction, showed that (i) the order of the affinity for Hg2+ is N,N′-dibenzoylated N2S4 crown (4)≈photoirradiated 1&gt;trans-1&gt;photoirradiated 2&gt;trans-2, (ii) neither trans-2 nor 4 shows significant affinity toward heavy metal ions such as Cu2+, Co2+, Ni2+, and Pb2+, (iii) trans-1 has a slight affinity (Ex% 5.9%) for Cu2+,whereas photoisomerized 1 shows the remarkably enhanced affinity (Ex% 93.9%) with Cu2+, and (iv) such light-induced improvement is not seen for 2. The relatively poor binding ability of 2 and 4 is rationalized in terms of the unfavorable inside-out conformation of the N2S4 crown ring. The remarkable affinity change in cis-1 is probably due to the cooperative contribution of the thiacrown and the azopyridine cap constructing a new ligand site. 1 was used as a carrier for Cu2+ transport through a liquid membrane. It was found that the rate is efficiently accelerated by UV-light irradiation.
Dissolution States of Normal Alkane Derivatives with a Polar Group in Water
Authors: Nishino Nobuo , Morimoto Satoshi , Nakamura Masao 
Published: July 2006

Abstract
This paper proposes a method by means of which the heat of solution at an infinite dilution of an organic compound in water, directly measured by means of calorimetry at a given temperature, is extended over a wide range of temperatures by the use of a phase diagram with water. The heat of solution at an infinite dilution in water over a temperature range from 290 to 350 K, which is estimated by this method for some alkanols and alkanoic acids, increases with a rise in the temperature and has a transition temperature from the exothermic region to the endothermic region which is close to the minimum dissolution temperature in the solubility curve in water for each substance. The increase in the heat of solution might be due to the breakdown of the iceberg formed around the alkyl group. The difference between the partial molar heat capacity at an infinite dilution and the molar heat capacity at the pure state, ΔScp\overset\ominus2, has its maximum at a certain temperature. The higher homolog shows a sharper curve with a lower maximum temperature. The curve of ΔScp\overset\ominus2vs. the temperature for 2- or 3-alkanol corresponds to that for the lower 1-alkanol. These facts reveal that a polar group, such as OH and COOH, would preferentially break the weaker structure of the iceberg within its breaking sphere, which structure should break down at a lower temperature.
Immunoassay Using a Metal-complex Compound as a Chemiluminescent Catalyst. IV. The Investigation of a Metal Porphine Complex as a Labeling Reagent
Authors: Hara Tadashi , Toriyama Motohiro , Miyoshi Hisayo , Syogase Shinji 
Published: July 2006

Abstract
Among the metal porphine and phthalocyanine complexes synthesized by the present authors, a iron(III) complex of 5,10,15,20-tetrakis(4-carboxyphenyl)porphine was found to be most sensitive for the chemiluminescence reaction of luminol–H2O2; it was successfully used in the determination of albumin as a protein model, with a detection limit of about 130pg.
Enantiodivergent Total Syntheses of Nanaomycins and Their Enantiomers, Kalafungins
Authors: Tatsuta Kuniaki , Akimoto Kohji , Annaka Masahiko , Ohno Yutaka , Kinoshita Mitsuhiro 
Published: July 2006

Abstract
The first, enantiospecific total syntheses of pyranonaphthoquinone antibiotics, nanaomycins D and A, and their enantiomers, kalafungin and 4-deoxykalafunginic acid are described by an “enantiodivergent” strategy from a common optically active intermediate, (1S,3RS,4S)-3,4-dihydro-5,9,10-trimethoxy-1-methyl-1H-naphtho[2,3-c]pyran-3,4-diol, which has been derived from l-rhamnose via condensation of 4-methoxy-3(phenylsulfonyl)-1(3H)-isobenzofuranone and methyl 3,4,6-trideoxy-α-l-glycero-hex-3-enopyranosid-2-ulose.
Topological Index and Thermodynamic Properties. III. Classification of Various Topological Aspects of Properties of Acyclic Saturated Hydrocarbons
Authors: Narumi Hideyuki , Hosoya Haruo 
Published: July 2006

Abstract
To elucidate the physical meaning of the structure-activity relationship of alkanes, correlation coefficients between 24 thermodynamic properties of hexane, heptane, octane, and nonane isomers and four different topological indices were calculated. These properties were classified into five different types depending on the signs and magnitudes of their correlation coefficients with the two indices, Z and p3. It is interpreted that Z and p3, respectively, represent the dynamical and static features of the topological properties of molecules. The merit of correlation pattern recognition is demonstrated.
The Theoretical Study of the Solvophobic Interaction
Authors: Ohba Masaharu , Arakawa Kiyoshi 
Published: July 2006

Abstract
The relation between a solvophobic interaction (SI) and a solute–solute radial distribution function is discussed. The SI is defined as the difference between the indirect part of the solute–solute potential of the mean force in a solvent and that in a “homomorphic” solvent. It was calculated using the RHNC-like integral equation of RISM-1 for a dilute solution of hard spheres in a solvent composed of polar hard dumb-bells. The existence of a SI was comfirmed in a simple system. The SI in this system proved to have originated from the effect of a dipole–dipole interaction between solvent molecules making the excluded volume of the solute molecules small. It was found that the strength of a SI decreases with increasing temperature. It was also shown that Ben-Nairn’s measure [J. Chem. Phys., 54, 1387 (1971)] gives an incorrect conclusion with respect to the temperature dependence of the SI of this system because it includes an excess factor irrelevant to a SI.
The Preparation and Some Properties of 1,4,7-Trithia[7]- and 1,5,9-Trithia[9]ferrocenophanes and Their Copper(I), Silver(I), Mercury(II), and Palladium(II) Complexes
Authors: Sato Masaru , Suzuki Kaoru , Akabori Sadatoshi 
Published: July 2006

Abstract
1,5,9-Trithia[9]ferrocenophane was prepared by the reaction of 1,1′-bis(3-chloropropylthio)ferrocene with sodium sulfide. The complexes of 1,5,9-trithia[9]ferrocenophane, along with 1,4,7-trithia[7]ferrocenophane, with copper(I), silver(I), mercury(II), and palladium(II) salts were prepared. Some interaction between the iron atom and the metal atoms coordinated to the thia-crown moiety was suggested from their spectral data in the solution for the complexes of 1,4,7-trithia[7]ferrocenophane with mercury(II) and palladium(II) salts and the complex of 1,5,9-trithia[9]ferrocenophane with silver(I) tetrafluoroborate.
Crystal Structure of the Mixed-Stacked Salt of Bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) and Tetracyanoquinodimethane (TCNQ)
Authors: Mori Takehiko , Inokuchi Hiroo 
Published: July 2006

Abstract
The crystal structure of the monoclinic form of (BEDT-TTF)(TCNQ) is determined by X-ray analysis. The donor (BEDT-TTF) and the acceptor (TCNQ) molecules are planar and form alternating stacks.
Temperature Dependence of the Reflectance Spectra of the Single Crystals of Bis(ethylenedithio)tetrathiafulvalenium Salts. α-(BEDT–TTF)3(ReO4)2 and α-(BEDT–TTF)2I3
Authors: Yakushi Kyuya , Kanbara Hirohisa , Tajima Hiroyuki , Kuroda Haruo , Saito Gunzi , Mori Takehiko 
Published: July 2006

Abstract
Polarized reflectance spectra were measured on the single crystals of α-(BEDT–TTF)3(ReO4)2 and α-(BEDT–TTF)2I3. The optical spectra of these materials were interpreted on the basis of a simple semimetallic band model, and the anisotropic character of the intermolecular interaction in these crystals was quantitatively examined by analyzing the observed spectra. The observed temperature dependence of reflectance spectrum reflects the change of the electronic structure accompanying the metal-insulator phase transition, and is consistent with our interpretation of the spectra.
Chemical Chameleons. Organosulfones as Synthetic Building Blocks
Authors: Trost Barry Martin 
Published: July 2006

Abstract
An overview of the duality of function of organosulfones as nucleophiles in basic media and electrophiles in Lewis acidic media, a change of reactivity for which they have been dubbed “chemical chameleons,” is presented. In the first phase, transition metal catalysts activate allyl sulfones towards displacements. Use of palladium, molybdenum, and nickel catalysts allow stabilized anions to effect displacement; copper catalysts allow non-stabilized nucleophiles to be used. The use of the anion stabilizing and leaving group abilities of sulfones created a novel three carbon intercalation and a novel cyclocontraction-spiroannulation in which β-hydroxy sulfones participate in a Lewis acid catalyzed pinacol rearrangement. The lability of allyl and tertiary sulfones towards Lewis acids creates a wide array of electrophilic reactions such as Friedel–Crafts type cyclizations, intermolecular alkylations with organoalanes and enol silyl ethers, and ring expansions. The ability to design novel reagents for synthesis based upon this dual reactivity of organosulfones is illustrated by the use of an alkoxy-bis(phenylsulfonyl)methane as a synthon for a carbonyl 1,1-dipole.
Excimer Formation and Intramolecular Self-Complexation of Double-Armed γ-Cyclodextrin
Authors: Hamada Fumio , Murai Koichi , Ueno Akihiko , Suzuki Iwao , Osa Tetsuo 
Published: July 2006

Abstract
Circular dichroism and fluorescence studies of γ-cyclodextrin bearing two naphthyl moieties (1) suggest that 1 exists as two intramolecular self-complexation forms in water-rich solutions with one or two of the naphthyl moieties included in its cavity. Upon addition of (−)-borneol as a guest, 1 forms a 1 : 1 host–guest complex, exhibiting slightly diminished excimer and circular dichroism bands. Ethylene glycol converts the intramolecular complexes into a relaxed form, in which two naphthyl moieties dangle outside the cavity.
(Remark: Graphics omitted.)
A New Type of Two-Dimensional Organic Conductors: Alkylammonium Bis[1,2,5]thiadiazolotetracyanoquinodimethanides
Authors: Suzuki Takanori , Kabuto Chizuko , Yamashita Yoshiro , Mukai Toshio , Miyashi Tsutomu , Saito Gunzi 
Published: July 2006

Abstract
Anion radical salts of bis[1,2,5]thiadiazolotetracyanoquinodimethan (BTDA) containing forty kinds of alkylammonium ions were prepared whose molar ratios are unique for each cation and changed from 1:1 (2A–2L) to 2:3 (2M–2Z), 1:2 (2a–2m), and 2:5 (2n) with elongation of the side chains. The electrical conductivities of the salts are largely affected by the molar ratio and the spatial requirement of cations (ρRT 3.1 Ω cm for 2a and 4.2×106 Ω cm for 2L), and some of the salts exhibit high electrical conductivities (ρRT 3.1–8.3 Ω cm for 2a–2e) with small anisotropy (ρ⁄⁄ 1.7 Ω cm, ρ⊥ 21.6 Ω cm for a single crystal of 2g). Three salts (2A, 2M, and 2g) showed semiconducting temperature dependence of electrical conductivity with the activation energies of 0.12–0.20 eV. The X-ray study of three kinds of the salts (2A, 2g, and 2m) revealed that two-dimensional networks are formed by S–N≡C interactions (3.12–3.33 Å) of BTDA anion radicals. The crystals of 2A and 2g showing higher conductivities consist of two-dimensionally expanded “ribbon” networks accompanied with equally spaced columnar stackings while molecules are pairing to form dyads in 2m which exhibits lower conductivity.
The Synthesis of 1,3-Dithiolan-2-ones On the Reaction of Oxiranes with Carbon Disulfide under High Pressure
Authors: Taguchi Yoichi , Yasumoto Masahiko , Shibuya Isao , Suhara Yasuo 
Published: July 2006

Abstract
An equimolar reaction of 2-hexyloxirane with carbon disulfide in hexane was run in the presence of triethylamine under 800 MPa at 100 °C for 20 h, and gave 63% of 4-hexyl-1,3-dithiolan-2-one (3a), 21% of 4-hexyl-1,3-dithiolane-2-thione (1a) and 5% of 5-hexyl-1,3-oxathiolan-2-one (4a). Hexane, benzene, and diisopropyl ether were good solvents for the reaction. The reaction of a variety of oxiranes with carbon disulfide produced 1,3-dithiolan-2-ones as the main products under 500 MPa at 100 °C for 20 h. Upon a reaction of 2-hexyloxirane with carbon disulfide, 5-hexyl-1,3-oxathiolane-2-thione (2a), and 2-hexylthiirane (5a) were produced during the first stage of reaction. The formation of 1a and 4a began immediately, whereas, the formation of 3a required a long induced period. A feasible mechanism for the formation of 3a is proposed to be a rearrangement of 2a in the presence of triethylamine, free from carbon disulfide.
A Convenient Synthesis of 4-(Perfluoroalkyl)pyrimidines and 4-(Perfluoroalkyl)tetrahydropyrimidines
Authors: Uno Hidemitsu , Matsushima Yuji , Tasaka Tadataka , Suzuki Hitomi 
Published: July 2006

Abstract
Vinyl perfluoroalkyl ketones formed in situ from the reactions of perfluoroalkyllithiums with ethyl acrylate can easily be trapped with thiouronium and amidinium salts to give 4-(perfluoroalkyl)tetrahydropyrimidines in moderate to good yields. Similarly, ethynyl perfluoroalkyl ketones generated in situ can be converted to 4-(perfluoroalkyl)pyrimidines, although the yields are low.
Absorption Spectra and Dynamics of the Triplet State in p-Terphenyl Powder Systems: a Diffuse Reflectance Laser Photolysis Study
Authors: Koshioka Masanori , Mizuma Hirokazu , Imagi Keiji , Ikeda Noriaki , Fukumura Hiroshi , Masuhara Hiroshi , Kryschi Carola 
Published: July 2006

Abstract
A microcomputer-controlled nanosecond diffuse reflectance laser photolysis system was developed and applied to p-terphenyl powder systems. The triplet absorption spectrum of microcrystalline powders is broader and red-shifted compared to the molecular triplet state in solution. Possible contributions of an optical artifact and an impurity were rejected by examining powder systems doped with naphthacene and diluted with NaCl as well as poly(methyl methacrylate). p-Terphenyl adsorbed on silica gel and included in β-cyclodextrin gave different triplet spectra, which are interpreted in terms of conformational structure of p-terphenyl. Decay processes and an oxygen effect are also discussed.
Reversible Color Changes of Polydiacetylene Induced by Monomer Solid Phase Transition
Authors: Araya Kotaro 
Published: July 2006

Abstract
Color change associated with solid phase transition is observed in the diacetylene derivatives, partially polymerized 4,6-decadiyne-1,10-bis(propylurethane). Moreover, the temperature of this color change can be altered by mixing with other derivatives.
Acute and chronic toxicity of nitrate to early life stages of lake trout (Salvelinus namaycush) and lake whitefish (Coregonus clupeaformis)
Authors: McGurk Michael D. , Landry François , Tang Armando , Hanks Chris C. 
Published: July 2006

Abstract
The acute and chronic toxicity of the nitrate ion (NO−3) to the embryos, alevins, and swim-up fry of lake trout (Salvelinus namaycush) and lake whitefish (Coregonus clupeaformis) were tested in laboratory aquaria. The acute (96-h) median lethal concentration (LC50) for swim-up fry was 1,121 mg NO3-N/L for lake trout and 1,903 mg NO3-N/L for lake whitefish. The chronic (˜130–150-d) LC50s for embryos to swim-up fry were 190 and 64 mg NO3-N/L, respectively. Sublethal effects on developmental timing and fry body size were observed at concentrations of 6.25 and 25 mg NO3-N/L, respectively, in the chronic tests. These results confirm that the Canadian nitrate water-quality guideline of 2.9 mg NO3-N/L, which was derived from chronic tests on a temperate-zone amphibian, is applicable to the early life stages of two species of Arctic fish. However, it does not support use of the guideline for acute exposures during early life stages of salmonid fish or for acute or chronic exposures to adult fish, which are relatively insensitive to nitrate.
Functional stability of microbial communities from long-term stressed soils to additional disturbance
Authors: Tobor-Kapłon Maria A. , Bloem Jaap , de Ruiter Peter C. 
Published: July 2006

AbstractFunctional stability, measured in terms of resistance and resilience of soil respiration rate and bacterial growth rate, was studied in soils from field plots that have been exposed to copper contamination and low pH for more than two decades. We tested whether functional stability follows patterns predicted by either the “low stress–high stability” or the “high stress–high stability” theory. Treatments consisting of soils with no or high copper load (0 or 750 kg/ha) and with low or neutral pH (4.0 or 6.1) were used. Stability was examined by applying an additional disturbance by heat (50°C for 18 h) or drying–rewetting cycles. After heating, the respiration rate indicated that the soils without copper were less stable (more affected) than the soils with 750 kg/ha. Bacterial growth rate was more stable (resistant) to heat in the pH 6.1 than in the pH 4.0 soils. Growth rate was stimulated rather than inhibited by heating and was highly resilient in all soils. The respiration rate was less affected by drying–rewetting cycles in the pH 4.0 soils than in the pH 6.1 soils. Bacterial growth rate after drying–rewetting disturbance showed no distinct pattern of stability. We found that the stability of a particular process could vary significantly, depending on the kind of disturbance; therefore, neither of the two theories could adequately predict the response of the microbial community to disturbance.
Estimating the combined toxicity by two-step prediction model on the complicated chemical mixtures from wastewater treatment plant effluents
Authors: Ra Jin Sung , Lee Byoung Cheun , Chang Nam Ik , Kim Sang Don 
Published: July 2006

Abstract
The toxicities of chemical mixtures containing 10 compounds, detected in wastewater treatment plant (WWTP) effluents, were investigated using Daphnia magna in a two-step prediction (TSP) model. The 10 chemicals determined by gas chromatography/mass spectrometry in WWTP effluents included three groups: Three acetylcholinesterase inhibitors, six narcosis inhibitors, and one seedling root inhibitor. In the first step, a concentration addition (CA) model was used to predict the mixture toxicities for the three component groups with similar modes of action; in the second step, an independent action (IA) model was used for the newly developed concentration–response curves from the three CA predictions. The CA predictions did not show a statistically significant difference from the observed results with respect to the three groups of chemicals, whereas the IA model did not conform to the experimental results. Therefore, the concentration–response curves obtained from the mixture toxicity tests in each group was considered as a single curve and applied in the next step of the mixture toxicity prediction. However, the observed toxicity of the 10-chemical mixture showed large differences from the results of the IA and CA model predictions, whereas the TSP model predicted the toxicity well and with statistical significance (p = 0.0501, n = 17). This suggests that the TSP model would provide a valid prediction for a randomly selected chemical mixture having various modes of action if the concentration–response function for an individual component is obtained.
Tolerance of nitrifying bacteria to copper and nickel
Authors: Fait Gabriella , Broos Kris , Zrna Sharyn , Lombi Enzo , Hamon Rebecca 
Published: July 2006

AbstractEvidence is mounting that soil microorganisms can become increasingly tolerant to metals on exposure. However, in situ investigations regarding the effects of metals, particularly Cu and Ni, on specific soil functions/communities are still limited in number. Here, we investigated whether preexposure of nitrifying bacteria to Cu or Ni can induce increased tolerance to these metals. We also investigated whether changes in the tolerance of populations exposed to Cu under field conditions (long term) or in a laboratory-spiked soil (short term) occur. The method used was specifically designed to avoid possible confounding factors because of aging of metals in soil. Sterilized soils were enriched with different concentrations of Ni or Cu and were inoculated with the same soil that was either uncontaminated or had been contaminated previously with metals. Nitrification was measured after 28 d. In the laboratory-spiked soil, the exposed nitrifier community showed an increased tolerance to Ni but not to Cu. However, we found an increased tolerance to Cu in the case of a nitrifying community exposed to Cu for nearly 80 years under field conditions. These results indicate that the capacity of nitrifying bacteria to adapt to at least some metals is a widespread phenomenon. However, acquisition of tolerance to Cu may be more difficult, or require more time, compared with tolerance to Ni.