bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Calorimetric Study of Ternary Zinc(II) Complexes with Chloride Ions and 2,2′-Bipyridyl in N,N-Dimethylformamide
Authors: Ishiguro Shin-ichi , Nagy László , Ohtaki Hitoshi 
Published: July 2006

Abstract
Formation equilibria of ternary zinc(II) complexes with chloride ions and 2,2′-bipyridyl (bpy) have been calorimetrically studied in N,N-dimethylformamide (DMF) containing 0.4 mol dm−3 (C2H5)4NClO4 as a constant ionic medium at 25 °C. Formation of binary (2,2′-bipyridyl)zinc(II) complexes has also been explored. The calorimetric data were satisfactorily explained in terms of formation of the ternary [ZnCl(bpy)]+ and [ZnCl2(bpy)] complexes together with the binary [Zn(bpy)n]2+ (n=1–3) ones, and their formation constants and enthalpies were determined. The formation of the ternary [ZnCl(bpy)]+ and [ZnCl2(bpy)] complexes is not so favorable in DMF. It is suggested that both [ZnCl(bpy)]+ and [ZnCl2(bpy)] complexes have the four-coordinate tetrahedral structure in DMF.
Cis-to-Trans Isomerization of Bis(diamine)bis(isothiocyanato)chromium(III) Thiocyanate in the Solid State
Authors: De Goutam , Suzuki Masatatsu , Uehara Akira 
Published: July 2006

Abstract
Solid-state thermal reactions of trans- and cis-[Cr(NCS)2(AA)2]SCN where AA is 1,2-ethanediamine (en) or 1,3-propanediamine (tn) were studied. Upon heating, both the cis- and trans-complexes lost half mole of diamine to convert into the double complex trans-[Cr(NCS)2(AA)2][Cr(NCS)4(AA)]. The anion moiety [Cr(NCS)4(AA)]− was isolated from the double complex. The thermal reactions are thus useful for easy preparation of [Cr(NCS)4(AA)]− complex, which has previously been obtained with difficulty from solution reactions.
Synthesis of 5-[(E)-1-Alkenyl]-3(2H)-furanones by the Stereoselective Dehydration with Me3SiCl
Authors: Sakai Takashi , Kohda Kazuhiko , Tsuboi Sadao , Utaka Masanori , Takeda Akira 
Published: July 2006

Abstract
The stereoselective dehydration of 5-(2-hydroxyalkyl)-3(2H)-furanones is accomplished conveniently by the treatment with Me3SiCl in acetonitrile to give 5-[(E)-1-alkenyl]-3(2H)-furanones.
A New Method for the Synthesis of 3,5-Disubstituted 2(5H)-Furanones. Synthesis of (±)-Acarenoic Acid
Authors: Tsuboi Sadao , Wada Hiroshi , Muranaka Koichi , Takeda Akira 
Published: July 2006

Abstract
Heating of 3,5-disubstituted 4-bromo-3-methoxycarbonyldihydro-2(3H)-furanones with NaI in 3-pentanone gave 3,5-disubstituted 2(5H)-furanones in 55.8–93.3% isolated yields. A total synthesis of (±)-acarenoic acid was established in 33% overall yield via 4 steps.
Synthesis of 5,8-Dihydroxy-2-methoxy-1,4-naphthoquinone Derivatives. A Major Naphthoquinone Moiety of Some of Naphthoquinone Antibiotics
Authors: Tanoue Yasuhiro , Terada Akira , Tsuboi Toshiyuki , Hayashida Takayuki , Tsuge Otohiko 
Published: July 2006

Abstract
6-Formyl- and 6-hydroxymethyl-5,8-dihydroxy-2-methoxy-1,4-naphthoquinones were, respectively, prepared from 2-formyl- and 2-hydroxymethyl-1,4,5,6,8-pentamethoxynaphthalenes which were synthesized as key intermediates of the new antibiotics containing 2-methoxynaphthazarin structure.
Synthesis and Spectroscopic Studies of 1,1′-(1,8-Naphthylene)di-1H-1,2,3-triazoles
Authors: Nagawa Yoshinobu , Honda Koichi , Nakanishi Hiroshi 
Published: July 2006

Abstract
The first 1,8-diheteroaromatic naphthalenes, 1,1′-(1,8-naphthylene)di-1H-1,2,3-triazoles (1), were synthesized by 1,3-dipolar cycloadditions of 1,8-diazidonaphthalene to acetylenic esters. The spectral properties of these compounds were studied and compared with those of the corresponding 1-(1-naphthyl)-1H-1,2,3-triazoles (2). The two triazole rings at the peri-positions in 1 are in a face-to-face arrangement according to the results of 1H NMR spectra. The UV spectra of 1 are almost identical with each other and show a red shift from those of corresponding 2. No significant spectral differences between 1 and 2 were observed in the IR spectra. The fragment ion with two azirine groups at the peri-position in the naphthalene ring was observed in the MS spectra of 1.
[2]Metacyclo- and [2]Paracyclo[2](1,3)ferrocenophanes
Authors: Hisatome Masao , Yoshihashi Masamichi , Yamakawa Koji , Iitaka Yoichi 
Published: July 2006

Abstract
[2]Metacyclo- and [2]paracyclo[2](1,3)ferrocenophanes (1 and 2) have been synthesized and characterized by means of X-ray diffraction and spectroscopy. The crystal data of the phanes were determined as follows: 1, monoclinic, P21 a=8.851(4), b=15.742(8), c=5.963(3) Å, β=109.76(5)°, Z=2; 2, orthorhombic, Pbca, a=15.308(8), b=24.716(12), c=8.034(4) Å, Z=8. The benzene rings of the both phanes are distorted in a similar manner to [2.2]cyclophanes but the planarities of the cyclopentadienyl (Cp) rings are maintained. The distance between the substituted Cp ring and the iron atom in 1 is considerably extended (1.678(4) Å) in comparison with ferrocene, whereas that of 2 (1.659(3) Å) is not. The 2-hydrogen of the Cp ring and the 9-hydrogen of the benzene ring in 1 are situated right above each other’s rings. In the 1H NMR spectrum of 1, the 2- and 9-protons shifted to highfield to a considerable extent (δ1.18 and 5.34, respectively) due to the diamagnetic anisotropic effects of the benzene and Cp rings. The electronic spectra of both phanes exhibited bathochromic shifts of the d–d absorption band of the iron (1, 451 nm, 2, 447 nm) as compared to [3]metacyclo- and [3]paracyclo[3](1,3)ferrocenophanes (each 442 nm), which were synthesized as reference compounds in this work.
ESR and FT-IR Studies for Coal Structures. Characteristics of Japanese Coals
Authors: Ito Osamu , Seki Hiroyuki , Iino Masashi 
Published: July 2006

Abstract
The ESR parameters (spin concentration, line width, g-value, and spin-lattice relaxation time) of various coals mined in Japan and in many foreign countries have been measured. Low spin concentrations, broad line widths, and long spin-lattice relaxation times have been recognized as characteristics of Japanese bituminous coals (e.g., Akabira, Miike, and Shin-yubari coals) compared with the foreign coals having similar carbon contents. The origins of these differences were interpreted by the aid of the FT-IR spectra. Low fractions of aromatic carbon and rich aliphatic groups of Japanese bituminous coals are closely related to the characteristics in the ESR parameters.
Crystal Structure and 35Cl NQR of Copper(II) Trichloroacetate Trihydrate
Authors: Kiriyama Hideko , Hashimoto Masao , Okuno Nanami 
Published: July 2006

Abstract
The crystal structure of the title compound has been determined by means of X-ray diffraction. The crystal data and the final R value are: Cu(CCl3COO)2·3H2O, monoclinic C2⁄c, a=23.082(3), b=6.253(1), c=9.726(2) Å, β=94.67(1)°, Z=4, R=0.049. The structure consists of monomeric Cu(CCl3COO)2(H2O)3 molecules, which are linked together by intermolecular O–H···O hydrogen bonds to form a layer parallel to (100). Each Cu(II) atom is coordinated by five oxygen atoms which form nearly a square pyramid; two oxygen atoms of two carboxylate ions and two water molecules form its basal plane and the remaining water molecule occupies the apical position. The mean basal Cu–O length is 1.961 Å and the apical one 2.183 Å. The Cu(II) atom is displaced from the basal plane by 0.110 Å toward the apical oxygen. Thermal analysis (DSC) disclosed two phase transitions at 163 and 207 K, their estimated molar enthalpies being about 0.4 and 0.7 kJ mol−1, respectively. At 77 K, 24 35Cl NQR signals are observed in the frequency range 38.7–40.3 MHz. The X-ray diffraction photographs for both low-temperature phases indicate the appearance of superstructures with less symmetrical space groups; the b spacing doubles below 207 K, while both b and c spacings double below 163 K.
Oscillatory Variation near the C–K Edge in the Photon W-Value of Ethylene
Authors: Suzuki Isao H , Saito Norio 
Published: July 2006

Abstract
The dependence of ethylene W-value on photon energy has been precisely measured in the region from 269 to 324 eV by using monochromatized synchrotron radiation. The W-value showed an oscillatory variation at the Cls→π* excited state as well as the C–K edge. A model has been proposed in which the inner-shell excitation gives rise to a change in the energy of the electron ejected from the molecule having absorbed a photon. It has been found that the model can reproduce the oscillatory variation feature of the W-value.
Lanthanoid Chirality as a Tool for Assignment of f–f Transitions. Tb3+ and Tm3+ Diglycolate
Authors: Karmakar Bhutnath , Chatterjee Prabir K , Basu Samita , Chowdhury Mihir 
Published: July 2006

Abstract
Although chiral studies have proved to be handy in the assignment of transitions in biological molecules, organic molecules and transition metal complexes, its potentiality for lanthanoid transition needs to be demonstrated. The paper explores the usefulness of CD studies in the assignment of lanthanoid transitions with two specific chiral single crystals–thulium diglycolate (Tm3+–DG) and terbium diglycolate (Tb3+–DG). It has been shown that chirality can distinguish ΔJ=0, ±1 transition from others. The need for studies under higher resolution has been pointed out.
Photochemical Reactions. 21. Sensitized Photooxygenation of N-Methylated 4-Aza-5-androsten-3-one and 4-Aza-5-androstene Steroidal Systems
Authors: Piniella Joan Francesc , Estapé Jordi , Lupón Pilar , Merino Luis , Puig Mariano , Bonet Juan-Julio , Briansó José Luis , Germain Gabriel 
Published: July 2006

Abstract
Two steroidal ene lactams, N-methyl-4-aza-5-androsten-3,17-dione and N-methyl-6-methoxy-4-aza-5-androsten-3,17-dione, and an enamine, N-methyl-4-aza-5-androsten-17β-ol, have been synthetized and their sensitized photooxygenations were investigated. The two ene lactams yield fragmentation compounds via the corresponding dioxetanes. Comparison with the previously reported behavior of an analogous N-unsubstituted ene lactam, seems to indicate that N-substitution is essential for the fragmentation to take place. On the other hand, the enamine yields a ketol. All results are briefly discussed from the mechanistic point of view.
Synthetic Photochemistry. XXXVIII. The Photorearrangement of the Tropone Endoperoxide, 6,7-Dioxabicyclo[3.2.2]nona-3,8-dien-2-one
Authors: Mori Akira , Takeshita Hitoshi 
Published: July 2006

Abstract
The photolysis of 6,7-dioxabicyclo[3.2.2]nona-3,8-dien-2-one produced six photolysates, including a cage γ-lactone which belongs to the same type of product as was characterized in each case of the photolysis of the endoperoxides derived from 2-aryl- and 2,7-diaryltropones by Mukai et al. The new products identified were 2,7-dioxabicyclo[3.2.2]nona-3,8-dien-6-one, a δ-lactone acetal, and 7-exoformyl-3-oxabicyclo[4.1.0]hept-4-en-2-one, a δ-lactone.
Fries Rearrangement of 1-Methoxy-4-(4-methyl-2- and -3-pentenoyloxy)benzenes
Authors: Tanoue Yasuhiro , Terada Akira 
Published: July 2006

Abstract
Not only rearrangement but also cyclization occurred in a Fries rearrangement of 1-methoxy-4-(4-methyl-2- and -3-pentenoyloxy)benzenes and gave 5,8-dihydroxy-4,4-dimethyl-3,4-dihydro-1(2H)-naphthalenone. The reduction and oxidation of the dihydronaphthalenone gave 5-hydroxy-8,8-dimethyl-5,6,7,8-tetrahydro-1,4-naphthalenedione and 8,8-dimethyl-7,8-dihydro-1,4,5(6H)-naphthalenetrione, respectively.
The Thermal Decomposition of Lithium Hydrogenphosphoramidate Trihydrate
Authors: Shimasaki Choichiro , Suzuki Hiroki , Toda Hiroshi 
Published: July 2006

Abstract
The thermal decomposition of lithium hydrogenphosphoramidate trihydrate LiHPO3NH2·3H2O was investigated by means of DTA–TG, X-ray diffraction analysis, IR, 31P NMR, and compositional analysis. The decomposition proceeds via an anhydrous phase, a newly found intermediate phase, and polyphosphates to lithium metaphosphate. The activation energies of the dehydration of the water of crystallization and of the polymerization reaction for the thermal decomposition were estimated to be 96.2 and 105.4 kJ mol−1 respectively.
Determination of Mercury by Graphite Furnace Atomic Absorption Spectrometry after Ion-Pair Extraction with Zephiramine in Small Scale
Authors: Okamoto Yasuaki , Kumamaru Takahiro , Hara Shigeki , Matsuo Hiroshi , Kiboku Mitsuo 
Published: July 2006

Abstract
A simple procedure for the determination of mercury(II) by graphite furnace atomic absorption spectrometry is described. Mercury(II) was extracted as tetradecyldimethylbenzylammonium (Zephiramine) thiocyanatomercurate(II) into diisobutyl ketone (DIBK) by using a 10-cm3 centrifuge tube, and an aliquot of the organic extract was directly pipetted out from the upper layer in the centrifuge tube and injected into the graphite furnace. The heating temperature program by ramp mode and the background correction by means of a 2-channel type atomic absorption spectrometer gave satisfactory results.
ESR Spectroscopic Study of Triphenylmethyl-Substituted Thioaminyl Radicals: N-(Triphenylmethylthio)alkylaminyls and -arylaminyls
Authors: Miura Yozo , Isogai Mamoru , Kinoshita Masayoshi 
Published: July 2006

Abstract
The title radicals, generated by hydrogen-atom abstraction from the corresponding N-(triphenylmethylthio)alkylamines and -arylamines, have been studied by means of ESR spectroscopy. The alkylaminyls were transient in solution at room temperature, while the arylaminyls persisted for a long period under the same conditions. The ESR parameters are discussed by comparing them with those for structurally related aminyls.
Application of the Flow Injection Analysis Based on Iodometry to the Determination of Ozone Decomposition Rate
Authors: Onari Yasuo 
Published: July 2006

Abstract
The determination of ozone decomposition rate by flow injection analysis (FIA) was investigated. Under the conditions studied a sampling rate was about 43 samples/h, and the pseudo-first-order kinetic plot of the obtained data showed a good linearity. This FIA method seems to be useful for kinetic measurement of ozone decomposition in water.
Improved Spectrophotometric Determinations of Cobalt(II) and Nickel(II) with Zincon in the Surfactants Micellar
Authors: Mori Itsuo , Fujita Yoshikazu , Fujita Kinuko , Tanaka Takeshi , Yano Yukari , Asada Makiko 
Published: July 2006

Abstract
Reactions between Zincon and cobalt(II) in the presence of N-hexadecylpyridinium chloride (cationic surfactant), and between Zincon and nickel(II) in the presence of poly(vinyl alcohol) (nonionic surfactant) are discussed in terms of the development of simple, sensitive and improved spectrophotometric determinations of cobalt(II) and nickel(II). The calibration graphs were rectilinear in the ranges 0–2.2 μg 10 cm−3 cobalt(II) with a Sandell sensitivity of 0.00015 μg cm−2 at 550 nm and 0–42.0 μg 10 cm3 nickel(II) with that of 0.0047 μg cm−2 nickel(II) at 470 nm. The proposed methods were relatively sensitive in comparison with the methods in the absence of surfactants with apparent molar extinctions of 4.6×105 for cobalt(II) and 2.4×104 dm3 mol−1 cm−1 for nickel(II). Separative assays of cobalt(II) and various metals (nickel(II), zinc(II), copper(II), and iron(III)) were possible by selections of analytical wavelengths, respectively.
Trace Determination of Indium by Electrolytic Preconcentration and Open Circuit Stripping via Localized Galvanic Cells
Authors: Jaya Sambamoorthy , Rao Talasila Prasada , Rao Gollakota Prabhakara 
Published: July 2006

Abstract
A galvanic stripping analysis procedure is described for the trace determination of indium(III). The determination involves the reoxidation of predeposited indium on the mercury-film-coated glassy carbon electrode in open circuit position (in the absence of external potential or current input or oxidant in solution). The reoxidation of indium was shown to occur due to the formation of localized galvanic cells. The time of reoxidation (stripping) was found to be proportional to the concentration of indium present in the solution (1 to 100 ppb). The details of the development of such a procedure and its possible application to determination of indium in zinc deposits and aluminium alloys are discussed.
Phenomenological Relationship between the Fluidity and Tracer-Diffusion in Concentrated Electrolyte Solutions
Authors: Tanaka Kazuko , Tamamushi Reita 
Published: July 2006

Abstract
An attempt has been made to correlate the mobility of component species with the fluidity of the solution over a wide range of concentration in aqueous solutions. A good linear correlation was observed between the relative fluidity and the relative tracer-diffusion coefficient of Cl− in aqueous solutions of LiCl, NaCl, MgCl2, CaCl2, and NiCl2, particularly at higher concentrations over 2 mol kg−1. The correlation for the cations was very similar to that of water in aqueous solutions of such electrolytes. The feature of these plots presents that the structural properties of concentrated electrolyte solutions are reflected on these correlations.
Hydrophobic Vitamin B12. V. Electrochemical Carbon-Skeleton Rearrangement as Catalyzed by Hydrophobic Vitamin B12: Reaction Mechanisms and Migratory Aptitude of Functional Groups
Authors: Murakami Yukito , Hisaeda Yoshio , Ozaki Toshiaki , Tashiro Takako , Ohno Teruhisa , Tani Yutaro , Matsuda Yoshihisa 
Published: July 2006

Abstract
The carbon-skeleton rearrangements as catalyzed by heptamethyl cobyrinate perchlorate, [Cob(II)7C1ester]ClO4, were investigated under electrochemical conditions. The controlled-potential electrolysis of 2,2-bis(ethoxycarbonyl)-1-bromopropane, which is considered to be a model substrate for methylmalonyl–CoA mutase, was catalyzed by [Cob(II)7C1ester]ClO4 in N,N-dimethylformamide to give the rearrangement product, 1,2-bis(ethoxycarbonyl)propane, as a major one at −1.5V vs. SCE in the presence of acetic acid and at potentials more cathodic than −1.8V vs. SCE without acetic acid in the dark. The electrochemical carbon-skeleton rearrangement was postulated to proceed via formation of anionic intermediates. The electrolyses of 1-bromo-2-cyano-2-ethoxycarbonylpropane, 2-acetyl-1-bromo-2-ethoxycarbonylpropane, and 1-bromo-2-[(ethylthio)carbonyl]propane with [Cob(II)7C1ester]ClO4 also afforded the corresponding carbon-skeleton rearrangement products. The results indicated that substrates with two electron-withdrawing groups placed on the β-carbon atom with combinations of one carboxylic ester and one of carboxylic ester, acetyl, and cyano moieties readily gave the corresponding rearrangement products which were derived from individual migration of the substituent groups. Substrates with only one of the electron-withdrawing groups, carboxylic ester, acetyl, and cyano, did not give any rearrangement product but a substrate with one thioester group afforded the corresponding rearrangement product. The migratory aptitude of electron-withdrawing groups was found to decrease in the order: COSR&gt;COR&gt;COOR&gt;CN. Both electronic character and steric bulkiness of the migrating groups are apparently reflected on this tendency, even though relative contributions of these effects are much dependent on the nature of β-substituents.
Effect of Molybdenum Codeposition on the Thermal Properties of Electroless Ni–B Alloy Plating Films
Authors: Osaka Tetsuya , Koiwa Ichiro , Yamada Keizo , Nishikawa Masao , Usuda Masahiko 
Published: July 2006

Abstract
Electroless Ni–Mo–B alloy films from a bath using dimethylamine–borane(1/1) (DMAB) as a reducing agent were investigated. Only a small amount of Mo-complex addition to the bath decreased the boron content and increased the molybdenum content drastically. The maximum molybdenum content and maximum resistivity under as-plated conditions were obtained as 22.1 wt% and 322 μΩ cm respectively. Such a high resistivity is characteristic of Ni–Mo–B alloy films. Both crystallized and amorphous states of Ni–Mo–B alloy films, whose Mo contents were above 20 wt% with a small amount of boron, were prepared by controlling the Mo-complex concentration in the bath. The heat change properties of Ni–Mo–B alloy films were quite different from those of the electroless Ni alloy films reported previously. The resistivity of Ni–Mo–B alloy films after heat treatment at 500 or 600 °C became higher than that of those created under as-plated conditions. The structure transformation of Ni–Mo–B alloy films after heat treatment was quite different from that of ordinary electroless Ni alloy films. The Ni–Mo–B alloy film after heat treatment was confirmed by TEM observation to show a mosaic-like structure. Therefore, it was thought that such a high resistivity and such thermal properties of Ni–Mo–B alloy films are caused by such a mosaic-like structure.
Influence of Br− Concentration on (Br)+-Mediated Indirect Electrooxidation of Alcohols to the Corresponding Carbonyl Compounds
Authors: Takiguchi Tsuyoshi , Nonaka Tsutomu 
Published: July 2006

Abstract
Current efficiency for the (Br)+(positive bromine species)-mediated indirect electrooxidation of alcohols to the corresponding carbonyl compounds decreased with increase in Br− concentration in dichloromethane and aqueous acidic solutions, while no concentration dependence was observed in an aqueous neutral solution. These facts suggested a general and practical guideline for the indirect electrooxidation, i.e. low Br− concentration is favorable in an electrolytic solution of low nucleophilicity. It was also found that the kind of (Br)+ species formed anodically in the absence of the alcohols in dichloromethane clearly depended on charge(Q) passed as follows: Br3− at Q≤2⁄3F mol−1 (1F=96480 C), Brn− (n&gt;3) at 2⁄3&lt;Q&lt;1F mol−1, and Br2 at Q=1F mol−1. Among these species, Br3− and Br2 seemed to be the weakest and strongest oxidizing agents, respectively. Lower efficiency for the indirect electrooxidation in higher Br− concentration was rationalized as due to more predominant formation of Br3− and/or Brn− with smaller n values.
Photochemical Stability of Polycyclic Aromatic Hydrocarbons in the Interstellar Medium
Authors: Aihara Jun-ichi 
Published: July 2006

Abstract
The astronomical IR spectra of molecular origin have been attributed to compact polycyclic aromatic hydrocarbons. This interpretation can be rationalized in terms of the percent resonance energies of the excited-state species. In general, large compact polycyclic aromatic hydrocarbons are not only thermodynamically stable but also photochemically stable. These hydrocarbons have large percent resonance energies in the excited state, and are expected to survive the rough conditions in space. In contrast, relatively small aromatic hydrocarbons are greatly destabilized when they are excited electronically or deprived of two π electrons.
Clogging and Gel-Layer Formation during Membrane Filtration and Its Effect on Analytical Data
Authors: Igawa Manabu , Yoshida Takeshi , Ohtake Chiaki , Hayashita Takashi 
Published: July 2006

Abstract
Clogging and gel-layer formation during membrane filtration affect the concentration of ions in the filtrate as well as the concentration of suspended solids. The flow rate analysis and the observation of the filter surface with a scanning electron microscope show that a gel-layer is formed subsequently after the clogging. Humic acids, fulvic acids, metal hydroxides, and soft particles dispersed in natural waters cause the clogging and hence the gel-layer formation. Cross-flow filtration decreases the rate of the clogging and the gel-layer formation and gives little rise to the filtration effects on analytical results.
Preparation and Characterization of U2O2F7
Authors: Asada Kameo , Ema Keiko , Iwai Takashi 
Published: July 2006

Abstract
Reaction of UO2F2 with UF5 at 400 °C under UF6-pressure of 3 atm followed by evaporation of excess UF5 has yielded a greenish white residue. Its X-ray diffraction pattern and infrared spectrum are sufficiently unique to establish that this material is a true compound. Its chemical formula has been shown to be U2O2F7, on the grounds of chemical analysis and thermal decomposition. The oxygen content was determined directly by means of 18O isotopic dilution method based on the combustion of the samples with BrF5.