bluuebunny/crossref_metadata_2025 huggingface dataset:
The Crystal and Molecular Structure of (N-Benzyl-l-alaninato)[N,N′-ethylenebis(α-methylsalicylideneaminato)]cobalt(III) Trihydrate
Authors: Kushi Yoshihiko , Tada Toshiji , Fujii Yuki , Yoneda Hayami
Published: July 2006

The crystal and molecular structure of the title complex (−)435-ΛRS-β2(mer)-[Co(α-Me-sal2en)(N-Bz-l-ala)]·3H2O, has been determined by single crystal X-ray analysis. The crystals are orthorhombic, space group P212121, with unit cell dimensions a=19.247(8), b=14.162(4), c=10.329(4) Å, and Z=4. The structure was solved by the heavy-atom method and refined by block-diagonal least-squares technique, using 1624 independent reflections, to the final R-value of 0.080. The molecular structure is of a ΛRS-cis-β2(mer) type in which two coordination sites of a distorted octahedron are occupied by the N-Bz-l-ala group and the others by the quadridentate α-Mesal2en Schiff-base ligand in a nonplanar configuration. The Co–O and Co–N bon lengths, 1.938(12) and 1.989(15) Å respectively, of the N-Bz-l-ala group are significantly longer than the usual values. The molecule is distinctly strained as shown by the bond angles of the ligands and those of the cobalt(III) coordination polyhedron. The water molecules form a hydrogen bonded chain linking phenolate and carboxylate oxygens of different molecules along the crystallographic c axis.
Potentiometric Study of Thermodynamic Parameters of Complexing of Lithium Ion–Basic Aprotic Solvents and Sodium Ion–Macrocyclic Polyethers in Acetonitrile
Authors: Nakamura Toshio , Yumoto Yasuke , Izutsu Kosuke
Published: July 2006

Formation constants of the 1 : 1 complexes of lithium ion in acetonitrile (AN) with DMF, DMSO, DMA, and HMPA and of sodium ion in AN with 15-crown-5 (15C5), 18-crown-6 (18C6), dibenzo-18-crown-6 (DB18C6), and cryptand 211 (Cryp 211), were determined at 10, 25, and 40 °C by potentiometric methods with a cationsensitive glass electrode. From the change of the formation constants with temperature, thermodynamic parameters ΔG298°, ΔH298° and −TΔS298°, were obtained. ΔG298°, ΔH298°, and −TΔS298° all in kJ mol−1, for Li+-solvent complexes were, respectively, −7.9, −9·0, +1·1 for DMF, −9.7, −10·1, +0·5 for DMSO, −10.0, −9·9, −0·1 for DMA, and −18.9, −15·8, −3·1 for HMPA, and those for Na+-macrocyclic polyether complexes, −28.4, −24·1, −4·5 for 15C5, −27.2, +1·6, −28·7 for 18C6, −28.6, −14·3, −14·2 for DB18C6, and −51.9, −53·8, +2·1 for Cryp 211. Some features about the roles of enthalpy and entropy terms in complexing have been discussed.
The Flow-injection Analysis of d-Glucose Using a Flow-cell with Immobilized Peroxidase and Its Application to Serum
Authors: Hara Tadashi , Toriyama Motohiro , Imaki Masakatsu
Published: July 2006

The d-glucose concentration in a serum sample of less than 0.01 cm3 could be continuously determined at the rate of about 20 samples/h by the use of a chemiluminescent reaction between luminol and hydrogen peroxide, a flow-cell with immobilized peroxidase, and a column with immobilized glucose oxidase. By immobilizing peroxidase as a chemiluminescent catalyst inside the flow-cell, simplification could be achieved with regard to apparatus, reagents and operation. The detection limit of hydrogen peroxide was about 5×10−6 mol dm−3, and the calibration curves for both hydrogen peroxide and d-glucose were approximately linear in the range of 5×10−5–1×10−3 mol dm−3, a range which corresponded to the glucose concentration, 0.1–18 mg cm−3, obtained by diluting serum to 50 times its initial volume.
A Calorimetric Study on the Relative Thermal Stability in Some Nickel(II) Complexes Containing N,N′- or N,N-Diethylethylenediamine
Authors: Tsuchiya Ryokichi , Uehara Akira , Ohtsuka Yoshiyuki
Published: July 2006

The enthalpy changes (ΔH) in the reaction of Ni(AA)2X2·nH2O type complexes with aqueous potassium cyanide were calorimetrically measured at 25 °C, where AA is N,N′-diethylethylenediamine (NN′-deen) or N,N-diethylethylenediamine (NN-deen); X is Cl−, Br−, I−, or NO3− ion; and n is 0 or 2. On the basis of the enthalpy data measured, the thermal stability was compared among chloride, bromide, iodide, and nitrate in the following each group of compounds: Ni(NN′-deen)2X2·2H2O, Ni(NN′-deen)2X2, Ni(NN-deen)2X2·2H2O, and Ni(NN-deen)2X2. The thermal stability was found to decrease in the order, chloride>bromide>nitrate>iodide in each group. Comparison of the enthalpy data between the chlorides of the NN′-deen and NN-deen complexes revealed the difficulty of anation in the latter rather than in the former. [Ni(NN-deen)2(H2O)2]Br2 was, when heated, converted into [Ni(NN-deen)2]Br2 without anation differing from the chloride. The difference was also discussed on the basis of the enthalpy data.
Orbital Tilting Due to Destabilizing Four-electron and Stabilizing Two-electron Orbital Interactions. An Elucidation of Exo-endo-nonequivalency of π-MO Extension of Norbornene
Authors: Ito Suketaka , Kakehi Akikazu
Published: July 2006

A new concept, “Orbital Tilting,” leading to hybridization change, was introduced on the basis of the destabilizing and the stabilizing secondary orbital interaction. The predominant π-MO extension of norbornene in the exo-direction was elucidated by application of the concept to the orbital system.
Photoreduction of Aminoanthraquinones by an Electron Transfer via the Upper Excited nπ* Triplet State
Authors: Inoue Haruo , Kawabe Kiyoshi , Kitamura Noboru , Hida Mitsuhiko
Published: July 2006

The photoreduction of 2-piperidinoanthraquinone (1) by an electron transfer from hydroxide ion in aqueous 2-propanol was reinvestigated. The reaction proceeded actively on irradiation at 365 nm, but very weakly on irradiation at 420 nm. The fluorescence of 1 was not affected by hydroxide ion. 1,3-Cyclohexadiene as a triplet quencher retarded the photoreduction. All results revealed that the reactive state of 1 in the photoreduction is not the intramolecular excited CT state, but the upper excited nπ* triplet state. Kinetic studies indicated that the rate of deactivation from the T2(3nπ*) level of 1 is unusually slow (kd=1.7×108 s−1). The photoreduction via the upper excited T2(3nπ*) level was also observed in 1-amino- and 1-piperidinoanthraquinone, while 2-aminoanthraquinone did not exhibit any reactivity. Wavelength-dependencies (313 nm, 365 nm, and >420 nm irradiations) of the photoreductions were also observed.
Interaction of Amylose with Iodine. I. Characterization of Cooperative Binding Isotherms for Amyloses
Authors: Yamamoto Masako , Sano Takayuki , Yasunaga Tatsuya
Published: July 2006

The interaction of amylose with iodine was investigated as a function of degree of polymerization (DP) of amylose by amperometric titration, and the binding isotherms were obtained. The intrinsic equilibrium constant and cooperative parameter were determined with a one-dimensional Ising model for amyloses of various DPs. The inflection of the plot of the intrinsic equilibrium constant vs. DP observed at about DP 60 suggests that a helical segment of amylose consists of anhydroglucose residues less than 60. The discontinuity of the cooperativity at about DP 60 was interpreted by two kinds of cooperative effects, intra- and interhelical effects. These results suggest that the interrupted helix is a good model for the amylose structure in aqueous solution. The temperature dependencies of the cooperative parameters show that the cooperativity of amylose-iodine complexation is entropycontrolled.
The Determination of the Ratio of Two Kinds of Hydrogen in Metal Hydrides by Means of Pulsed NMR
Authors: Hayashi Shigenobu , Hayamizu Kikuko , Yamamoto Osamu
Published: July 2006

A method is proposed by which the composition of the two kinds of hydrogen with different diffusional behavior in metal hydrides can be determined accurately by means of 1H NMR; using the method, it is found that the energy difference between the two sites occupied by the two kinds of hydrogen is 7.9 kJ/mol in VH0.77.
Reduction by a Model of NAD(P)H. 36. First and Direct Evidence for the Multi-step Mechanism
Authors: Yasui Shinro , Nakamura Kaoru , Ohno Atsuyoshi , Oka Shinzaburo
Published: July 2006

Reductions of thiobenzophenone derivatives with a model compound of NAD(P)H, 1-benzyl-1,4-dihydronicotinamide (BNAH) or N-(α-methylbenzyl)-1-propyl-2,4-dimethyl-1,4-dihydronicotinamide (Me2PNPH), in a solvent containing an O-deuterated alcohol afforded products partially deuterated at their methine positions. The deuterium content depends both on the character of substituents in the substrate and on the polarity of solvent. In contrast, no incorporation of deuterium into the product was observed in the reduction of thiopivalophenone with BNAH or Me2PNPH under the same conditions. These results can be accounted for in terms of an electron transfer followed by a proton transfer from the model to substrate. This is the first and direct evidence for the ion radical-pair intermediacy for reductions by model compounds of NAD(P)H.
Effect of Molecular Size on the Association of p-Quinone Anion and Lithium Ion in N,N-Dimethylformamide
Authors: Nagaoka Tsutomu , Okazaki Satoshi , Fujinaga Taitiro
Published: July 2006

Ion pair formation effects of metal ions on the electro-reduction of p-quinones in N,N-dimethylformamide were studied systematically by polarography. The formation constants of 1 : 1 and 1 : 2 associates, as evaluated by the 1/F02-weighted least squares method, decrease with increase in the anion size.
Synthesis and Lithiation of 2-Alkylthio- and 2-Arylthio-1,3-dithiolanes
Authors: Tanimoto Shigeo , Oida Tatsuo , Ikehira Hideyuki , Okano Masaya
Published: July 2006

Several 2-alkylthio- and 2-arylthio-1,3-dithiolanes were synthesized by the reaction of 2-ethoxy-1,3-dithiolane with aliphatic and aromatic thiols in the presence of ZnCl2. The lithiation of 2-alkylthio-1,3-dithiolanes with butyllithium in tetrahydrofuran followed by the addition of alkyl halides gave unsymmetrical dialkyl trithiocarbonates in moderately good yields.
The Synthesis and Electrical Resistivities of Complexes of Cation–TCNQ–Salts with Crown Ethers, Cryptands, and 1,13-Di(8-quinolyl)-1,4,7,10,13-pentaoxatridecane
Authors: Matsuoka Katsumi , Nogami Takashi , Matsumoto Tsuruyoshi , Tanaka Hidekazu , Mikawa Hiroshi
Published: July 2006

Cation–TCNQ complexes with crown ethers, cryptands, and 1,13-di(8-quinolyl)-1,4,7,10,13-pentaoxatridecane were isolated. The cations include alkali-metal, and alkyl- and arylammonium ions. Nine types of complexes were isolated. These complexes are classified into two groups: complexes containing neutral TCNQ, and the complexes not containing neutral TCNQ. The electrical resistivities of the compaction samples were mainly measured at room temperature. The complexes containing neutral TCNQ were much more conductive than the other type of complexes; they exhibit resistivities of 8.2–103 Ω cm. The complexes of 1,13-di(8-quinolyl)-1,4,7,10,13-pentaoxatridecane contained methanol when we synthesized them from methanol solution.
Photoelectrochemical Reduction of Carbon Dioxide at p-Type Gallium Phosphide Electrodes in the Presence of Crown Ether
Authors: Taniguchi Yasuhiko , Yoneyama Hiroshi , Tamura Hideo
Published: July 2006

Reduction of carbon dioxide at p-type GaP photocathodes was investigated in lithium carbonate electrolytes. The reduction occurs in competition with hydrogen evolution and its current efficiency is enhanced by dissolving crown ether such as 15-crown-5 in the electrolyte. It is proposed that a chemical reaction pathway is involved in which the reduction of carbon dioxide is initiated by cathodically deposited lithium with formation of the anion radical of carbon dioxide.
Phosphinyl- and Phosphinothioylamino Acids and Peptides. VI. The Protection of the Hydroxyl Function in the Tyrosine Side-chain by the Dimethylphosphinothioyl Group
Authors: Ueki Masaaki , Inazu Toshiyuki
Published: July 2006

The use of the dimethylphosphinothioyl(Mpt) group for the protection of the hydroxyl function in the tyrosine side-chain was studied. N,O-Bis(Mpt)tyrosine was obtained directly by a Schotten-Baumann-type reaction of Mpt–Cl with tyrosine. The O-Mpt group was stable under acidic conditions, and it could be removed easily by alkaline hydrolysis or ester-exchange reaction. The usefulness of this new protecting group for the peptide synthesis was shown in the solid-phase synthesis of [d-Ala2, l-Leu5]-enkephalin(H–l-Tyr–d-Ala–Gly–l-Phe–l-Leu–OH) and its N-allyl derivative.
The Crystal and Molecular Structure of Cu(AlCl4)2
Authors: Kitajima Nobumasa , Shimanouchi Hirotaka , Ono Yoshio , Sasada Yoshio
Published: July 2006

The structure of copper(II) tetrachloroaluminum Cu(AlCl4)2 was determined by the single-crystal X-ray diffraction technique. The crystal is triclinic: a=6.582(6), b=7.362(5), and c=12.265(5) Å; α=89.99(5), β=85.97(6), and γ=89.77°; space group P\bar1 and Z=2. The structure was solved by the heavy-atom method and refined by applying the block-diagonal matrix least-squares technique on 2628 independent reflections up to a final R value of 0.110. The structure consists of closely-packed centrosymmetric Cu(AlCl4)2 molecules with copper atoms tetragonally coordinated. Structural difference between Cu(AlCl4)2 and Co(AlCl4)2 is described.
Circular Dichroism Spectra of fac(D)-[Co(a)(BC)(DDD)n+ Type Complexes with 1,4,7-Triazacyclononane, (2R)-2-Methyl-1,4,7-triazacyclononane, and 1,5,9-Triazacyclododecane
Authors: Fujinami Shuhei , Matsunami Yukio , Shibata Muraji
Published: July 2006

The complexes, [Co(l-val)(NH3)(tacn)]2+ (tacn=1,4,7-triazacyclononane), [Co(gly)(NH3)(Me-tacn)]2+ (Me-tacn=(2R)-2-methyl-1,4,7-triazacyclononane) have been prepared and separated into diastereomers by column chromatography. Six other complexes, [Co(a)(β-ala)(tacn)]n+ (a=CN−, NO2−, or NH3) and [Co(a)(gly)(tacdd)]n+ (a=NO2−, NCS−, or H2O; tacdd=1,5,9-triazacyclododecane) have also been prepared and resolved into enantiomers. By comparing the CD spectra of the l-valinato and the Me-tacn complexes with that of [Co(gly)(NH3)(tacn)]2+, the optical activities of [Co(a)(gly)(tacn)]+ are considered to be mainly derived from chiral arrangements of four kinds of donor atoms. The change from five-membered chelate ring to a six-membered one has slight influence upon the CD spectral shapes in the β-alaninato complex, but a large influence in the tacdd complexes.
Ion-pair Extraction of Nickel(II) and Copper(II) Complexes of 8-Hydroxy-7-nitroso-5-quinolinesulfonic Acid with Zephiramine
Authors: Ozaki Toyoko
Published: July 2006

The ion-pair extraction of nickel(II) and copper(II) complexes of 8-hydroxy-7-nitroso-5-quinolinesulfonic acid (H2NQS) with zephiramine(benzyldimethyltetradecylammonium chloride) was studied. It was found that slope analysis can be used to determine the mechanism of these ion-pair extraction systems, as well as the continuous-variation method for three component systems or the mole-ratio method by choosing appropriate extraction conditions. As a result, the equation of these extraction equilibria can be represented as:

M2++2HNQS−+2ZCl(o)\ightleftharpoonsM(NQS)2Z2(o)+2Cl−

The extraction constants and the exchange constants were calculated.
Pyrolytic Sulfurization Gas Chromatography. XI. An Improved Apparatus and Procedure for Practical Use
Authors: Hara Tadashi , Okui Fujio
Published: July 2006

With the objectives of reducing the time necessary for an analysis and of improving the precision and accuracy of the analysis value, the isothermal gas-chromatographic optimum conditions were investigated and established. By the present method, the time necessary for an analysis is reduced to 25 min, from 35 min under the previous conditions, and both precision and accuracy are further improved together with an improvement of the calculation method of the calculation factors used in the calculation of the atomic ratio between C, H, O, and N. Thus many standard samples, including some liquid ones which are newly examined in this study, can be analyzed within an absolute error of about ±0.2%.
Kinetics and Mechanism of Decompositions of N-Methyl-N′-aryl-N-nitrosoureas and Related Compounds in Aqueous Buffer Solution
Authors: Yoshida Kitaro , Yano Kazuyuki
Published: July 2006

The decomposition reactions of N-methyl-N′-aryl-N-nitrosoureas (1) and of N,N′-dimethyl-N′-aryl-N-nitrosoureas (2) were studied kinetically in phosphate buffer solution. All nitrosoureas 1 were easily hydrolyzed even under neutral conditions and the rates of hydrolysis were found to be proportional to the hydroxide ion concentration over pH range 5.4–7.6. General base catalysis by buffer components was negligible. The reaction was subjected to the elimination mechanism in which an abstraction of the ureido proton was involved as an initial step. On the other hand, nitrosoureas 2 had no significant reactivity under the same conditions.
Bis(2,4-pentanedionato)phenylchromium(III). Preparation and Reactions with Organic Carbonyl Compounds and Alcohols
Authors: Ito Takashi , Ono Tsukasa , Maruyama Kazunori , Yamamoto Akio
Published: July 2006

A phenylchromium complex CrPh(acac)2 (1) (acac=2,4-pentanedionato ligand) was prepared from Cr(acac)3 and AlPh3·Et2O. Complex 1 reacts with acetone to give benzene, 2-phenyl-2-propanol, and mesityl oxide and is converted into a hydroxo complex [Cr(OH)(acac)2]2. The mechanism involving the insertion of the carbonyl group of acetone into the Ph–Cr bond giving an alkoxo intermediate is proposed. Reactions of 1 with esters proceed similarly to give diphenylmethanol derivatives and alkoxochromium complexes. Complex 1 reacts with ROH to give benzene and alkoxo complexes [Cr(OR)(acac)2]n [n=1 or 2) which were characterized by means of IR spectra, elemental analyses, molecular weight measurements, magnetic susceptibilities, and chemical reactions. The reactions of 1 with β-dicarbonyl compounds yield corresponding mixed chelate complexes Cr(β-dic)(acac)2, where β-dic=diethyl malonato and 1-ethoxy-1,3-butanedionato ligands.
The Crystal and Molecular Structure of 1-(2-Amino-4-pyrimidinyl)-β-carboline
Authors: Yokomori Yoshinobu , Sekido Kiyotane , Wu Tian-Shung , Tien Hsien-Jun , Hirokawa Sakutaro
Published: July 2006

An alkaloid extracted from a small evergreen tree, Annona montata, was identified as 1-(2-amino-4-pyrimidinyl)-β-carboline monohydrate by the X-ray method. The crystal data are; a=20.699, b=4.453, c=15.720 Å, and β=112.16°; space group, P21/c; Z=4. The structure was solved by the direct method and refined by the least-squares method to the final R value of 0.109 for 1451 independent reflections. The water molecule is connected to four nitrogen atoms by hydrogen bonds. Two of them are in different groups; one is in the five-membered ring of the β-carboline skelton, and the other is in the pyridine of the β-carboline skelton. The fifth hydrogen bond connects two nitrogen atoms, one of which is in the amino group, and the other, in the pyrimidine skelton.
Salt Effects on the Intramolecular Cannizzaro Reaction of Phenylglyoxal. Specific Acceleration by Calcium Ion
Authors: Okuyama Tadashi , Kimura Kazumasa , Fueno Takayuki
Published: July 2006

Effects of added salts on the rate of alkaline rearrangement of phenylglyoxal to mandelic acid were examined in aqueous solution at 30 °C. The reaction showed positive salt effects. Specific acceleration was found with some metal ions, the efficiency decreasing in the order Ca2+>Tl+>Sr2+>Ba2+.
Analysis of the Excess Gibbs Energies of Binary Mixtures Using Non-randomness Factors Determined from Excess Volume Data
Authors: Kato Masanao
Published: July 2006

An analytical equation for the excess Gibbs energies of mixtures was derived on the basis of the non-random two-liquid model, which was applied to the derivation of an analytical equation for excess volumes proposed by the present author. The derived equation involves new adjustable parameters of intermolecular interaction. The validity of the equation was examined for 13 binary mixtures by using the non-randomness factors determined from the excess volume data, and it was shown that the calculated excess Gibbs energies were in good agreement with the observed values. The sequence of the values of the interaction parameters seems to be reasonable.
The Structure of the Cyclodextrin Complex. XIII. Crystal Structure of β-Cyclodextrin–1,4-Diazabicyclo[2.2.2]octane Complex Tridecahydrate
Authors: Harata Kazuaki
Published: July 2006

The crystal structure of β-cyclodextrin–1,4-diazabicyclo[2.2.2]octane complex tridecahydrate was determined by the X-ray method. The crystal is monoclinic with the space group P21, Z=2, a=15.395(2), b=16.598(1), c=15.441(2) Å, and β=117.35(1)°. The structure was solved by inspection of a Patterson map and a trial-and-error method combined with the rigid-body least-squares technique and refined by the block-diagonal least-squares method to the final R-value of 0.048 for 5649 reflections (sinθ⁄λ<0.61). The β-cyclodextrin molecule is in the shape of a distorted and truncated heptagonal pyramid. Two of seven primary hydroxyl groups are in a gauche-trans conformation, the others being in a gauche-gauche conformation. Secondary hydroxyl groups form intramolecular hydrogen bonds between adjacent glucose residues. The guest 1,4-diazabicyclo[2.2.2]octane is almost fully included in the cavity of β-cyclodextrin. Its methylene groups are in van der Waals contact with the methine groups and the glycosidic oxygen atoms at the interior surface of β-cyclodextrin, while two nitrogen atoms form hydrogen bonds with a water molecule and a secondary hydroxyl group of the neighboring β-cyclodextrin. β-Cyclodextrin molecules are arranged nearly parallel to the crystallographic ac plane to form a corrugated sheet of molecular layer. All of the thirteen water molecules fill vacant spaces between the molecular layers, forming a hydrogen-bond network in the crystal.
New Potent Neuroleptic Drugs of Benzamide Derivatives. I. Crystal and Molecular Structure of N-[(2RS, 3RS)-1-Benzyl-2-methyl-3-pyrrolidinyl]-5-chloro-2-methoxy-4-methylaimnobenzamide
Authors: Furuya Toshio , Iwanami Sumio , Takenaka Akio , Sasada Yoshio
Published: July 2006

The crystal and molecular structure of the title compound has been determined by the X-ray diffraction method. The crystal is monoclinic, space group P21/c, a=11.694(1) Å, b=12.117(1) Å, c=14.482(1) Å, β=100.01(1)°, and Z=4. The structure was solved by the direct method and refined by a block-diagonal least-squares procedure to a final R value of 0.082. An intramolecular hydrogen bond between the amide nitrogen and the methoxyl oxygen atoms forms a new six-membered ring fused with the benzene ring. Structural features are discussed in relation to neuroleptic activity.
Phase Transition in Concentrated Latices and the Electrical Double Layer on Their Surfaces
Authors: Furusawa Kunio , Yamashita Satoshi
Published: July 2006

The phase diagrams of monodisperse latices were constructed under the various conditions. The variable of the phase diagrams, the particle size, the surface charge densities of the latices, the counter-ion valences, and the medium temperature were taken up. The results, especially, the coexistent/ordered boundary curves were analysed in terms of the closed packing of the effective particle volumes which consisted of the latex particles which were surrounded by the electrical double layer. The value of 1.5 kT ergs of electrical repulsion, when used as a criterion in the DLVO potential to back-calculate the weight fraction of solid contents as a function of KCl concentration, yields a curve that is very similar to the experimental boundary curve. The same agreement was found in the curves mapped out for the other latices with a different particle size and a different surface charge density using KCl as an electrolyte. In the boundary curve constructed using MgCl2, however, the agreement with the analyses was not enough where the divalent cation would be adsorbed preferentially on their surfaces as a Stern layer charge. The temperature effect could be reasonably explained by the same procedure.
Ruthenium-catalyzed Reduction of Carbonyl Compounds Using Formic Acid
Authors: Watanabe Yoshihisa , Ohta Tetsuo , Tsuji Yasushi
Published: July 2006

Carbonyl compounds were hydrogenated to the corresponding alcohols in excellent yields using formic acid with a ruthenium complex at 125 °C for 3 h. 2-Propanone was reduced to 2-propanol by RuCl2(PPh3)3–HCOOH system in 94% yield with 98% selectivity. 3-Pentanone, cyclohexanone, acetophenone, and propiophenone were hydrogenated to the corresponding alcohols in 86, 78, 84, and 86% yields respectively. The ketone having the bulkier alkyl groups showed lower reactivity. The catalytic activity was found to decrease in the order RuCl2(PPh3)3, RuHCl(PPh3)3, RuHCl(CO)(PPh3)3, and RuH2(PPh3)4.
Intramolecular 1,3-Dipolar Cycloadditions and Intramolecular Ene Reactions of 2-(Alkenyloxy)benzaldehyde Arylhydrazones
Authors: Shimizu Tomio , Hayashi Yoshiyuki , Kitora Yoshitaka , Teramura Kazuhiro
Published: July 2006

2-(3-Aryl-2-propenyloxy)benzaldehyde (or 1-naphthaldehyde) arylhydrazones undergo an intramolecular cycloaddition reaction via their 1,3-dipolar tautomers, azomethine imines, to the alkenyl group. Initial cycloadducts were converted to dehydrogenated compounds under the reaction conditions. On the other hand, introduction of cyano or ethoxycarbonyl groups instead of the aryl group into 3-position of the ortho propenyloxy group gave 3-cyanomethyl-4-chromanone arylhydrazones or the corresponding ethoxycarbonyl derivatives, respectively. The formation of these hydrazones was interpreted in terms of intramolecular ene reaction. The course of the reactions depends on the nature of the alkenyl substituents.
Restricted Rotation Involving the Tetrahedral Carbon. XLIII. Buttressing Effect on Rotational Barriers in Bromine-substituted 9-(2-Methoxy-4,6-dimethylphenyl)fluorenes
Authors: Aoki Masahiro , Nakamura Mikio , Oki Michinori
Published: July 2006

9-(2-Methoxy-4,6-dimethylphenyl)fluorenes carrying one or two bromo groups on the phenyl ring were prepared and the buttressing effect on the rotational barrier about the C9–Cph bond were investigated. The free energies of activation for rotation were 26.5, 25.9, and 27.2 kcal/mol at 56 °C for 3-bromo, 5-bromo, and 3,5-dibromo compounds, respectively. The buttressing effect was enhanced when the bromo group was next to the methoxyl group relative to that given to the methyl group. The results were attributed to the fact that a methoxyl group, which gives its steric effect by the oxygen atom in the normal cases, has to take conformations, not coplanar with the phenyl ring, caused by the presence of the bromo group.
The Influence of Molecular Conformation on the Electronic Relaxation Processes. Biphenyl in Solution
Authors: Fujii Tsuneo , Komatsu Shigeru , Suzuki Satoshi
Published: July 2006

The fluorescence spectra of biphenyl in an isopentane and methylcyclohexane mixture, in propylene glycol, and in glycerol have been observed as a function of temperature and excitation wavelength. The temperature dependence of the fluorescence spectra is interpreted in terms of the intramolecular geometric relaxation. The fluorescence spectra of biphenyl have been observed in various solvents at room temperature. The Ham effect was found in the biphenyl fluorescence.
The Interaction of a Neutral Polymer with Small Ions in Solution. II. The Binding of Alkali Metal Ions to Poly(oxyethylene) in Several Organic Solvents
Authors: Awano Hiroshi , Ono Katsumichi , Murakami Kenkichi
Published: July 2006

The conductivities for several solutions of alkali metal salts, such as potassium thiocyanate, containing poly(oxyethylene) (POE) have been measured as functions of the POE concentration, Cp. A decrease in the conductivity with an increase in Cp has been observed, particularly in methanol, acetonitrile, propylene carbonate, and sulfolane. For these systems, the binding of the cation has been evaluated from the decrease in conductivity and analyzed by a method based on the one-dimensional lattice model. As well as the solvent effects, the effects of the salt concentration and the effect of the alteration of salt on the binding constant have been discussed.
The Conversion of Methanol into Hydrocarbons over Dodecatungstophosphoric Acid
Authors: Baba Toshihide , Sakai Junya , Watanabe Hideki , Ono Yoshio
Published: July 2006

Dodecatungstophosphoric acid (TPA) is a very effective catalyst for the conversion of methanol into hydrocarbons. The effects of the reaction parameters, such as the temperature or the methanol partial pressure, were therefore examined. The kinetic features of the conversion over TPA are quite different from those over ZSM-5 zeolites. This difference is caused by the unique nature of the conversion over TPA; methanol molecules are sorbed and undergo the conversion in the bulk of solid TPA.
Syntheses of Sodium-Calcium Zeolites at Atmospheric Pressure and 80 °C. I. Reagents Used: Na4SiO4, Al(OH)3, Ca(NO3)2
Authors: Katsuki Kazuko , Majima Kyunosuke
Published: July 2006

Sodium-calcium zeolite minerals were synthesized in an electric oven at 80 °C for 1–5 weeks from suspensions of a suitable combination of the starting materials, which had a chemical composition of 2nNa2O·2CaO·Al2O3·nSiO2·xH2O(4≤n≤20, x=83–610). All of the synthetic products were obtained as massive products in the gel. X-Ray and IR analyses and a quantitative analysis of the principal ingredients showed these massive products to be well-crystallized hydroxycancrinites which contained 0–4.9% calcium oxide.
Sublimation Behavior of Actinoid Chelates of 2,2,6,6-Tetramethyl-3,5-heptanedione
Authors: Amano Ryohei , Sato Akiko , Suzuki Shin
Published: July 2006

Vacuum sublimation-recrystallizing temperatures were determined for a tracer amount of actinoid chelates of 2,2,6,6-tetramethyl-3,5-heptanedione in order to obtain information about their sublimation behavior. The influence of the amount of sample (in tracer scale or in milligram scale) on its sublimation-recrystallizing temperature was also examined. The sublimation-recrystallizing zone temperature of the tracer amount of chelate was lower than that of the milligram amount. In addition, the sublimation-recrystallizing zone temperatures of the actinoid chelates were found to be in the following sequence: UO22+>Am(III), Cm(III)>Th(IV), Np(IV), Pu(IV)>Cf(III). These results suggest that the sublimation technique can be applied to separate the actinoid elements in a carrier-free state.
Stepwise Reduction of Samarium and Ytterbium in the Polarographic Reduction Process in the Presence of 1,4,7,10,13,16-Hexaoxacyclooctadecane
Authors: Yamana Hajimu , Mitsugashira Toshiaki , Shiokawa Yoshinobu , Suzuki Shin
Published: July 2006

Polarographic reduction of La, Pr, Nd, Sm, Gd, Dy, Er, and Yb was investigated in the aqueous solutions containing 1,4,7,10,13,16-hexaoxacyclooctadecane (18-CROWN-6). It is shown that Sm(III) and Yb(III) are reduced stepwisely via the divalent state in the presence of 18-CROWN-6. The divalent state is stabilized by the complex formation with 18-CROWN-6.
The Oxidation Behavior of Various Organic Compounds on the Determination of Chemical-oxygen Demand by Means of Flow-injection Analysis with Acidic Permanganate
Authors: Korenaga Takashi , Ikatsu Hisayoshi , Moriwake Tosio
Published: July 2006

Forty-five organic compounds have been oxidized with an acidic permanganate solution under various oxidation conditions. In an attempt to determine the standard substance for chemical oxygen demand (COD), their oxidation behavior is analyzed in detail with respect to the reaction temperature and the reaction time by means of flow-injection analysis using ammonium iron(II) sulfate as the internal standard. The compounds used are classified into three groups according to the oxidation values obtained by the standard CODMn method. The results show that the compounds with oxidation values of more than 50% are easily oxidized with acidic permanganate, even under relatively mild conditions; those with oxidation values of 5–50% are severely influenced by the reaction temperature and the reaction time, and those with oxidation values of less than 5% are seldom oxidized at below 100 °C or for less than 30 min. As a standard substance for COD, it has been established that a mixture of the compounds has to be properly chosen from the aforementioned three groups according to the oxidation behavior of the water sample. The addition of silver nitrate to the oxidation system accelerates the oxidation reaction with acidic permanganate, whereas that of phosphoric acid suppresses the oxidation of organic compounds.
A Comparative Study on the Synthesis and Ion-exchange Behaviour of Tin(IV) Salts of Different Heteropolyanions. Separations of Metal Ions on Tin(IV) Boratomolybdate Columns
Authors: Ashfaq Nabi Syed , Siddiqi Zia Mahmood , Farooqi Wajahat Umar
Published: July 2006

Various samples of tin(IV) boratomolybdate, tin(IV) boratotungstate, tin(IV) boratophosphate, tin(IV) arsenatoborate and tin(IV) boratosulfate has been synthesized by mixing aqueous solutions of appropriate reagents in different volume ratios at pH=1. One of the samples of tin(IV) boratomolybdate has been studied in greater detail for its ion-exchange capacity, thermal and chemical stability, pH-titration and chemical composition. A comparison of few properties of tin(IV) boratomolybdate has been made with other tin(IV) salts of different heteropolyanions. Distribution coefficients of 24 metal ions on tin(IV) boratomolybdate in water, nitric acid, water–dioxane, and nitric acid–dioxane systems have been determined. The effect of temperature on the sorption behaviour of metal ions has also been studied. It has been found that Kd value increases in general with the increase in temperature. The differential selectivity of metal ions on tin(IV) boratomolybdate reveals that tin(IV) boratomolybdate is a useful ion exchanger for the separation of metal ions. As a result ten important separations have been quantitatively achieved on the columns of this ion-exchange material.
The Promotion Effect of Rare Earth Oxides on the Hydrogenation of Carbon Monoxide over Rh–Al2O3 Catalyst
Authors: Takita Yusaku , Yoko-o Tamiyasu , Egashira Naoyoshi , Hori Fumiaki
Published: July 2006

The addition of Dy2O3, Nd2O3, Yb2O3, La2O3, or Gd2O3 to the Rh–Al2O3 catalyst enhanced the activity of the hydrogenation of CO to methane. There was the linear relationship between the carbon skeleton propagation of the hydrocarbons formed and the basicity of the rare earth oxides.
The Color Isomerism of Oxovanadium(IV) Complexes with Tetradentate Schiff Base
Authors: Kasuga Kuninobu , Nagahara Takeo , Yamamoto Yasuo
Published: July 2006

An oxovanadium(IV) complex with N,N′-bis(1-methyl-2-bromo-3-oxobutylidene)ethylenediamine gave green and yellow forms in the solid state, depending upon the solvents used for recrystallization. A polymeric structure was proposed for the yellow form.
Substitution Reaction of In-plane Ligand in Bis(dimethylglyoximato)cobalt(II) Complex with N,N′-Disalicylideneethylenediamine
Authors: Mita Keisuke , Hotta Kazuhiko , Watanabe Shoji
Published: July 2006

A spectrophotometric study of the reaction Co(dmgH)2+salenH2→Co(salen)+2 dmgH2, in which dmgH2 is dimethylglyoxime and salenH2 is N,N′-disalicylideneethylenediamine, was carried out in methanol at 22 °C. The reaction rate decreased with increased amounts of added pyridine, and reached a stationary value at the molar ratio [pyridine]/[Co(dmgH)2]=1. The form of the rate expression was d[Co(salen)]/dt=k[Co(dmgH)2] where the rate constant k=0.023 min−1.
CIDNP Studies of the Oxidation of N-(p-Tolylsulfonyl)-N′-triphenylmethylhydrazine
Authors: Yoshida Masato , Yano Akira , Kobayashi Michio
Published: July 2006

The 13C-CIDNP spectra were observed during the oxidation of N-(p-tolylsulfonyl)-N′-triphenylmethylhydrazine. The formation of sulfone and sulfinic ester as recombination products in a solvent cage was established from the signs of polarization.
Information Chemistry and Molecular Evolution of Protein. Evolutionary Tree of Calmodulin
Authors: Iida Yôichi
Published: July 2006

The amino acid sequences of calmodulin, one of calcium-binding proteins, taken from bovine brain, scallop, sea anemone, and tetrahymena were compared to examine its molecular evolution. By the use of maximum parsimony method, its evolutionary tree was constructed, It was found that this protein has changed much more slowly than have such proteins as cytochrome c.
Anormalous Halogen to Dimethylamino Replacement with N,N-Dimethylformamide Catalyzed by Ethylenediamine or 2-Aminoethanol
Authors: Yamamoto Hiroshi
Published: July 2006

1- And 2-chloroanthraquinone and 2-amino-4-chloro-6-hydroxypyrimidine exclusively gave the dimethylamino derivatives upon heating in DMF at 90 °C in the presence of ethylenediamine or ethanolamine. A possible reaction pathway for this unusual exchange reaction was discussed.
Copper(II) Halide Catalyzed Cyclopropanation of Olefins Involving Dehydrobromination of Bromomalonic Ester by Amine
Authors: Kawabata Nariyoshi , Yanao Shinji , Yoshida Jun-ichi
Published: July 2006

The reaction of olefins with bromomalonic ester and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) proceeded in the presence of a catalytic amount of copper(II) halide to give 1,1-bis(alkoxycarbonyl)cyclopropane derivatives. DBU was converted into DBU-hydrobromide during the reaction. The reaction was electrophilic and proceeded nonstereospecifically.
Phase Transitions of the 1 : 2 Complex of N-Ethyl-N-methylmorpholinium and 7,7,8,8-Tetracyanoquinodimethan, MEM(TCNQ)2 above Room Temperature
Authors: Kobayashi Hayao
Published: July 2006

The thermal expansion coefficient, the electrical conductivity, and the crystal structure (at 325 K) of MEM(TCNQ)2 were examined. A new phase transition was observed at 315 K, where the thermal expansion coefficient jumps. This second-order transition may be triggered by the molecular motion of MEM cations and can be regarded as a precursor of the first-order transition around 62 °C. The molecular motion of MEM cations reduces the electrostatic lattice energy and leads to a structural change. The structural instability of TCNQ columns around 335 K is not attributable to the electron-electron correlation effect in the one-dimensional system, but to the change in the energy balance between the charge-transfer interaction and the electrostatic energy.
Freezing-Thawing Hysteresis Phenomena of Biological Systems by the New Method of Proton Magnetic Resonance
Authors: Suzuki Ei-ichiro , Nagashima Nobuya
Published: July 2006

An automatic recording system was developed for unfrozen water content and spin-spin relaxation time measurements as continuous functions of temperature, by using a broad-line pulsed NMR spectrometer and a minicomputer. The advantages of this system are that the exact quantitative measurements can be done by calibrating the nonlinearity of the NMR sensitivity, and that for high sensitivity temperature measurement the thermocouple with special device is directly immersed in a sample. Three types of freezing-thawing hysteresis phenomena, (1) recrystallization of solute(hydroxy-l-proline, d-mannitol) and refreezing of released hydrated water molecules in frozen aqueous solutions, and (2) hysteresis as the characteristic feature of gels(gelatin, αsl-casein), and (3) supercooling of capillary water in water-insoluble materials(zein, yeast RNA, cellulose) were analysed. The usefulness of this system as an analytical instrument of hydration properties of biological materials is emphasized.
Polarized Raman Spectrum of Maleic Anhydride Crystal
Authors: Ishibashi Yoshimi , Shimada Ryoichi , Shimada Hiroko
Published: July 2006

The polarized Raman spectrum of the maleic anhydride single crystal was studied. Prominent polarization behavior of the Raman bands was observed. Assuming the oriented gas model, the relative intensities of the non-totally symmetric intramolecular vibrations in various polarized Raman spectra were studied based on the data of the crystal structure. The assignments of the fundamental vibrational frequencies for maleic anhydride were reinvestigated through the polarization behavior of the Raman bands as well as the normal coordinate calculation.
Temperature Dependence of Raman Spectra of Pyridine in Hydrogen Bonding Solvents
Authors: Fukushima Kunio , Yamaji Masahiro
Published: July 2006

Raman spectra of pyridine in solvents of various hydrogen bonding powers were recorded and frequency shifts of some bands were measured. With methanol as solvent, Raman spectra recorded at temperatures between 128 and 293 K exhibit a remarkable change with temperature. Results are interpreted on the basis of possible existence of a σπ-complex.
Thermochemical Studies on Thioacetamide and Tetramethylthiourea. Estimation of Stabilization Energies Due to Interaction between Thiocarbonyl Group and Neighbouring Nitrogen Atom
Authors: Inagaki Sadayasu , Murata Shigeo , Sakiyama Minoru
Published: July 2006

Standard energy of combustion at 298.15 K and standard enthalpy of sublimation as a function of temperature were determined for thioacetamide and tetramethylthiourea by oxygen bomb combustion calorimetry and sublimation calorimetry. Derived standard enthalpies of formation in crystalline and gaseous states at 298.15 K are −(70.6±1.1) and (12.7±1.2) kJ mol−1, respectively, for thioacetamide, and −(38.3±2.3) and (44.7±2.4) kJ mol−1, respectively, for tetramethylthiourea. Stabilization energies of these molecules were evaluated by estimating the standard enthalpies of formation in gaseous state for the hypothetical reference structures by use of the group contribution method.
The Structure and Properties of the Triaquahexakis(methylthioacetato)dineodymium(III) Polymer, [Nd2(C3H5SO2)6(H2O)3]n, and the Same-ligand Complexes of Lanthanoid Elements
Authors: Kondo Satoshi , Shimoi Mamoru , Ouchi Akira , Takeuchi Toshio
Published: July 2006

The crystal and molecular structure of the title complex has been determined by the X-ray diffraction method. The crystal was triclinic, space group P\bar1, a=12.80(1), b=16.65(1), c=8.659(9) Å, α=104.6(1), β=93.7(2), γ=107.5(1)°, Z=2, DX=1.892(3), Dm=1.91(2) Mg m−3, μ(Mo Kα)=3.45 mm−1, and the final R value was 0.051 for 3577 reflections. The coordination number of both neodymium atoms is nine, although the coordinated atoms around one neodymium atom are arrayed in a tri-capped trigonal prism, and those around the other neodymium atom, in a mono-capped tetragonal antiprism. The neodymium atoms are arrayed on a linear chain bridged by the ligand; however, no metal-metal interaction is observed. The corresponding complexes of cerium(III), praseodymium(III), and europium(III) form isomorphous crystals with the title complex, but the complex of lanthanum(III) has the formula of ML3·4.5H2O (HL=(methylthio)acetic acid), and the complexes of dysprosium(III) and ytterbium(III), ML3·2H2O.
Conductometric Study of Ion-Ion and Ion-Solvent Interactions. III. Conductances of Silver Acetate in Acetonitrile–Water Mixtures at 25 °C
Authors: Raju U G Krishnam , Sethuram Bangalore , Rao T Navaneeth
Published: July 2006

Conductances of the solutions of silver acetate in 10 to 90% (w/w) acetonitrile–water mixtures were measured at 25 °C. The molar conductances at infinite dilution and association constants were calculated, using the Fuoss-Hsia equation with Fernandez-Prini coefficients. There was no association in 10 and 20% acetonitrile. The logKA  vs. 1/D plot was a straight line with negative intercept in accordance with the modified Denison-Ramsey theory of ion-pair formation. Walden products were also calculated. From these results it was concluded that silver ions are preferentially solvated by acetonitrile whereas acetate ion is hydrated in acetonitrile–water mixtures.
The Crystal and Molecular Structures of Tetronolide
Authors: Hirayama Noriaki , Kasai Masaji , Shirahata Kunikatsu , Ohashi Yuji , Sasada Yoshio
Published: July 2006

Tetronolide is an aglycone moiety of novel antitumor antibiotics tetrocarcins. The space group of the crystal is P212121 with a=20.138(3), b=22.680(3), c=7.848(1) Å and Z=4. The structure was solved by direct methods and refined by the block-diagonal least-squares using 3577 independent reflexions. The final R value was 0.085. It is established that tetronolide is [1R-(1R*,3R*,4R*,4aR*,6aR*,7E,10R*,11E,12aS*,13R*,16aR*,20aR*,20bS*)]-1,2,3,4,4a,6a,9,10,12a,13,16,20,20a,20b-tetradecahydro-4,10,13,21-tetrahydroxy-1,3,7,11,20a-pentamethyl-18,20-dioxo-18H-16a,19-metheno-16aH-benzo[b]naphth[2,1-j]oxacyclotetradecin-15-carbaldehyde or its enantiomer.
Adsorption of Surface Active Agents on Coals
Authors: Esumi Kunio , Meguro Kenjiro , Honda Hidemasa
Published: July 2006

The interactions between surface active agents and coals with various carbon contents were studied by measuring adsorption isotherms and zeta potentials. A characteristic adsorption behavior was observed for the coals among three different surface active agents, but no correlation was found between the adsorption and the carbon content of the coal.
Copper(II) Complexes of Schiff Bases Derived from Histamine or 2-(2-Aminoethyl)pyridine and 2,3-Butanedione or 4-Hydroxy-4-methyl-2-pentanone
Authors: Abe Masahiro , Nakao Yasuo , Suzuki Shinnichiro , Kimura Masazo , Nakahara Akitsugu
Published: July 2006

Copper(II) complexes of Schiff bases derived from histamine or 2-(2-aminoethyl)pyridine and 2,3-butanedione or 4-hydroxy-4-methyl-2-pentanone were prepared and characterized by elemental analyses, electronic and ESR spectra, and polarographic half-wave potentials. The relationship between structure of the chelates and the reduction potentials of copper(II) in these complexes was discussed in some detail.
Chemical Studies on the Mistletoe. IV. The Structure of Isoglucodistylin, a New Flavonoid Glycoside Isolated from Taxillus kaempferi
Authors: Sakurai Atsushi , Okada Kyoji , Okumura Yasuaki
Published: July 2006

A new flavonoid glycoside, isoglucodistylin was isolated from Taxillus kaempferi, and (2R,3S)-taxifolin 3-β-d-glucopyranoside was assigned to this substance from studies on the hydrolysis products and on the isomerization products, and from analyses of the carbon-13 NMR spectra.
The Behavior of Carbon Black in a Detergent Solution
Authors: Yoneyama Yuji , Ogino Keizo
Published: July 2006

The behavior of carbon black (CB) in a detergent (sodium dodecyl sulfate (SDS): 20%, zeolite: 20%, sodium silicate: 5%, sodium carbonate: 3%, sodium (carboxylatomethyl)cellulose (CMC): 1%, sodium sulfate: 51%) solution is discussed in terms of the ζ-potential and potential energy of interaction. The ζ-potential of CB in each solution of SDS, various builders, and the detergent was measured by microelectrophoresis. The potential energies between CB and fabrics (nylon and cellulose), between CB and clay, and between CB and zeolite were calculated by the use of the theory of heterocoagulation. The potential energy between one CB particle and another CB particle was calculated by the use of D-L-V-O theory. The ζ-potential was increased by the addition of builders, except sodium sulfate. The high negative ζ-potential of CB in the detergent solution resulted from the effect of builders. From the potential energies, it became evident that 1) CB in the detergent solution deposits with difficulty onto fabrics; 2) The CB coagulates with zeolite only with difficulty; 3) The CB coagulates with clay or CB.
The Isomerization of Butenes over KC8
Authors: Tsuchiya Susumu , Misumi Takatoshi , Ohuye Noriyuki , Imamura Hayao
Published: July 2006

The isomerization of butenes over KC8 has been investigated. The double-bond-migration and the cis-trans isomerization took place over KC8, but the skeletal isomerization could not be observed. From the rates of reactions and the selectivity ratios, all six of the relative rate constants and the activation energies of reaction were determined. The reaction paths on the triangular graph calculated from the rates constants show the cis-convex-type profile, which suggests one of the catalytic characteristics of KC8.