bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of Hydroxoaquo- and Diol-Type Cobalt(III) Complexes with Analogues of Nitrilotriacetic Acid
Authors: Uehara Akira , Kyuno Eishin , Tsuchiya Ryokichi
Published: July 2006

The following hydroxoaquo- and diol-type cobalt(III) complexes were prepared: K[Co(OH)(α-abda)(H2O)]·2H2O (I), K[Co(OH)(vda)(H2O)]·1.5H2O (II), K[Co(OH)pgda(H2O)] (III), K2[nipda Co(OH)2Co nipda]·2H2O (IV), K2[(α-abda) Co(OH)2Co (α-abda)]·3H2O (V), K2[vda Co(OH)2Co vda]·3H2O (VI), K2[lda Co(OH)2Colda]·2H2O (VII) and K2[pgda Co(OH)2Co pgda]·2H2O (VIII), where α-abda, vda, pgda, nipda and lda are the abbreviations of d,l-α-amino-n-butyric-N,N-diacetate, l-valine-N,N-diacetate, d-α-phenylglycine-N,N-diacetate, nitriloisopropionicdiacetate and l-leucine-N,N-diacetate ions, respectively. From the measurements of electronic spectra, conductivities and coagulation values and the results of derivatography, it was found that the diol complexes IV–VIII were also formed from the correspoindng hydroxoaquo complexes in the thermal reaction process.
The Chromium(III) Complexes with Natural α-Amino Acids
Authors: Mizuochi Hisayuki , Uehara Akira , Kyuno Eishin , Tsughiya Ryokichi
Published: July 2006

The following chromium(III) complexes with natural α-amino acids were prepared: [Cr(α-ambut)3]·2H2O (red) (I), (−)546-[Cr(l-leu)3]·2H2O (red) (II), (+)546-[Cr(l-leu)3]·2H2O (red) (III), [Cr(l-glu)3]·2H2O (red) (IV), (+)546-[Cr(l-lys)2(H2O)2]Cl·3H2O (red) (V), [Cr(OH)(α-ambut)2(H2O)]·H2O (light purple) (VI), [Cr(OH)(l-val)2(H2O)]·H2O (light purple) (VII), [Cr(OH)(l-leu)2(H2O)]·H2O (light purple) (VIII) and [Cr(OH)(l-glu)2(H2O)]·H2O (light purple) (IX), where α-ambut, l-leu, l-glu, l-lys, and l-val are the basic forms of α-aminon-butyric acid, l-leucine, l-glutamine, l-lysine and l-valine, respectively. From the results of electronic and infrared absorption spectra, molar conductivities and behaviors toward ion exchangers, the composition and structures of the complexes were determined. The striking information obtained is that the complexes (I)–(IV) are considered to have all the β-form unlike the corresponding cobalt(III) complexes having both α- and β-forms. On the basis of ORD and CD measurements, the complexes (II), (III), and (V) were found to be optically active.
Studies of Peptide Antibiotics. XXIV. Synthesis of 4,4′-d-Alanine-gramicidin S
Authors: Lee Sannamu , Ohkawa Reiko , Izumiya Nobuo
Published: July 2006

In order to investigate the contribution to antibacterial activity of the d-phenylalanine residues at 4- and 4′-position in gramicidin S, 4,4′-d-alanine-gramicidin S (XX) and 4-d-alanine-semigramicidin S (XXI) were prepared and tested for antibacterial properties. XX exhibited recognizable activity though weaker than that of gramicidin S, whereas XXI showed no activity on any of the microorganisms tested.
The Reactions of α-Substituted Carbonyl-stabilized Sulfonium Ylides with Succinic Anhydride
Authors: Mukaiyama Teruaki , Hagio Katsuaki , Takei Hisashi , Saigo Kazuhiko
Published: July 2006

It was found that various kinds of α-substituted carbonyl-stabilized sulfonium ylides were conveniently prepared from the corresponding sulfonium salts by treating with 50% aqueous sodium hydroxide. The reactions of sulfonium ylides with succinic anhydride afforded furofuran derivative by one step procedure in yields ranging these from 5 to 14%. The structures of furofuran derivatives were confirmed by IR spectrum, NMR sepctrum, degradation, and its behavior toward alkali and acid.
Substituents Effects on the Azo-Hydrazone Tautomerism of 4-Arylazo-2,6-di-t-butylphenols
Authors: Manda Eiichiro
Published: July 2006

The substituents effects on the azo-hydrazone tautomerism of 4-arylazo-2,6-di-t-butylphenols in carbon tetrachloride were studied by means of infrared and visible spectra. The substituents effects on their absorption spectra were discussed. The azo tautomers are predominant in the tautomeric equilibria of 3′- and 4′-substituted derivatives. Considerable participations of the hydrazone tautomers are found in the equilibria of the 2′-substituted derivatives having substituents capable of forming intramolecular hydrogen bonding with hydrazone-hydrogen atom. In the equilibria of 2′,6′-disubstituted derivatives, the positions of the equilibria move some what to the azo side from those of the corresponding 2′-substituted derivatives.
Hydrogenation and Hydrogenolysis. XIII. The Hydrogenation of Ethyl 4-Methyl-1-cyclohexenyl Ether over Platinum Metal Catalysts
Authors: Nishimura Shigeo , Katagiri Mamoru , Watanabe Tetsuo , Uramoto Masayoshi
Published: July 2006

The hydrogenation and hydrogenolysis of ethyl 4-methyl-1-cyclohexenyl ether (I) have been investigated with six unsupported platinum metals as catalysts at 25°C under atmospheric pressure of hydrogen. The hydrogenation of I in ethanol was accompanied by the formation of 4-methylcyclohexanone diethyl acetal (II), the extent of which depended on the nature of the catalyst metals. The ratio of the acetal formation to hydrogenation increased with respect to the catalyst metals in the sequence Os<Ru<Ir<<Rh<Pd<Pt. The amount of the hydrogenolysis to give methylcyclohexane increased in the order Pd≅Ru<<Os<Rh<Ir<<Pt at an initial stage of the hydrogenation in ethanol. This order in hydrogenolysis was explained in terms of the action of the ionized hydrogen on the catalyst surface and the olefin isomerization activity of the catalyst metals. The stereochemistry of the hydrogenation of I was also studied and the results were interpreted on the basis of the proposed mechanism. I was also hydro-genated in t-butyl alcohol and isopropyl ether as solvents and, except in a few cases, the proportion of hydrogenolysis decreased with solvent in the order ethanol>t-butyl alcohol>isopropyl ether. The stereoselectivity in ether formation did not differ much among the solvents except over palladium.
55Mn Nuclear Magnetic Resonance Studies of the Compounds with Manganese-Tin Bonds
Authors: Onaka Satoru , Miyamoto Takeshi , Sasaki Yukiyoshi
Published: July 2006

The nature of Mn–Sn bonds has been studied by 55Mn-NMR and IR spectroscopies of a series of compounds, R3−xXxSn–Mn(CO)5, where R is C6H5 or CH3 and where X is Cl or Br. Molecular orbital considerations have shown that the chemical shift of the 55Mn-NMR spectra is a measure of the σ-polarity of the L–Mn bond in L–Mn(CO)5-type complexes, and that the linewidth is mainly determined by the π-interaction between Mn and Sn. The π-interaction (back-donation from Mn to Sn) seems to be most pronounced in Br3Sn–Mn(CO)5 in the series of (CH3)3−xBrxSn–Mn(CO)5 compounds. The relationships among the chemical shift, the wave numbers of CO stretching modes, and the eqQ, are also shown.
The Catalytic Dehydrogenation, Dehydroxylation, and Dehydroxymethylation of Benzyl Alcohol. III. The Effect of Metal Chlorides as Additives
Authors: Ishige Masayoshi , Sakai Koji , Kawai Masatoshi , Hata Kazuo
Published: July 2006

This paper will describe the reaction of benzyl alcohol in the presence of various kinds of modified stabilized nickel catalysts, which had been prepared from the mother catalyst by treating it with solutions of appropriate metal chlorides. The catalytic activities of each modified catalyst for the formation of benzene, toluene, and benzaldehyde were compared in terms of the fH,fCH3, and fCHO values; the selectivities for the formation of benzene and toluene against that of benzaldehyde, SH and SCH3, were also evaluated. In general, the formation of toluene and benzene was greatly affected both by the kind and by the amount of metal chlorides used as additives. The reaction was promoted by the addition of a proper quantity of alkali metal chloride. In the cases of the reactions by lowlymodified catalysts, the decreasing order of the fH and fCH3 values according to the kind of metal ion adsorbed on the catalyst was as follows: Na+≥K+>Co2+>Ca2+>Cd2+>Ba2+>Hg2+>Cu2+. On the other hand, in the higher degrees of modification, the corresponding order of the fH and fCH3 values was altered to be as follows: K+>Na+>Co2+>Cd2+>Ba2+≥Ca2+>Cu2+>Hg2+. With regard to the modified nickel catalysts treated with 0.08 n solutions, it was found that the sequence of the fH and fCH3 values due to the kind of metal ion was roughly correlated with that of the atomic numbers of the corresponding metals. The results are discussed in connection with the general concept of catalytic chemistry.
The Preparation and Thermal Decomposition of Alkyl Acyl Dithiol- and Trithiocarbonates. A Convenient Method for the Synthesis of Thiolesters
Authors: Yoshida Hiroshi , Ogata Tsuyoshi , Inokawa Saburo
Published: July 2006

New alkyl acyl dithiol- and trithiocarbonates (1 and 2) were prepared from acid chlorides and tetramethylammonium alkyl dithiol- and trithiocarbonates (3 and 4). 1 and 2 decomposed at around 100°C to give the corresponding thiolesters in good yields. The kinetic studies of the decomposition of 1 and 2 showed that, in o-dichlorobenzene, the decomposition reaction was first order and that it proceeded via a four-membered intramolecular cyclic mechanism.
Methylation of Phenol over Metallic Oxides
Authors: Kotanigawa Takeshi , Yamamoto Mitsuyoshi , Shimokawa Katsuyoshi , Yoshida Yuji
Published: July 2006

Methylation took place only at ortho position of phenol under ah atmospheric pressure at 350°C when the reaction was carried out over an MO–Fe2O3 catalyst containing Cu, Mg, Ca, Ba, Zn, Mn, Co, or Ni each as M. The aromatic fraction in liquid products was only o-cresol and 2,6-xylenol and products substituted at para and meta positions could not be obtained. However, gasification of methanol took place simultaneously as a side reaction. From the relation between methylation and gasification, the catalytic activity was found to be effective in the order Cu>Zn>Ba>Ca>Co>Mn>Mg>Ni. Deactivation of these catalysts was observed before the reaction reaches a steady state. The thermogravimetric curve of the used catalyst was measured. From thermal analysis the reduction of the catalyst seems to be a cause of deactivation in addition to deposition of carbonaceous materials onto the catalyst surface. The used catalysts were reclaimed through the process of Scheme 1.
Macro Rings. III. The Synthesis of [2.1.1.1]Paracyclophane
Authors: Kawato Toshio , Inazu Takahiko , Yoshino Tamotsu
Published: July 2006

Two new macrocyclic compounds, I and II, which incorporate, respectively, four or eight benzene rings and intervening methylene bridges attached to their para positions, were synthesized. The UV, IR, and NMR spectra of these paracyclophanes were compared with a corresponding open-chain compound, III.
Solid Complex Formation of Aminomalonic Acid with Glycine
Authors: Kinugasa Toshio , Nishijo Juziro , Hashizume Genzo , Imanishi Isamu
Published: July 2006

It was found by X-ray analysis that aminomalonic acid forms a solid complex with glycine in a molar ratio of 1 : 1 on crystallization from an aqueous solution. DTA-TGA of the solid complex at a heating rate of 1.0°C/min in air showed that the solid complex decarboxylates at higher temperature, but more slowly than aminomalonic acid and that both endothermic and following exothermic peaks which were distinctly observed in the region of decarboxylation of aminomalonic acid at temperatures 108–140°C are only slightly observed at 168–175°C. Activation energies in the thermal decomposition of aminomalonic acid and the solid complex, caluculated from themogravimetric curves, were 69.4 kcal/mol and 21.3 kcal/mol, respectively. The results indicate that aminomalonic acid is thermally more stabilized than the acid itself by forming the solid complex with glycine.
Proton Spin-Lattice Relaxation Studies of Intermolecular Interactions in Acetic Acid Solution
Authors: Sato Kazuo , Nishioka Atsuo
Published: July 2006

Proton spin-lattice relaxation measurements were carried out by the rapid-passage method on the hydroxyl and methyl protons of acetic acid in carbon tetrachloride, benzene-d6, and chloroform-d in order to investigate the effect of the self-association of acetic acid on the spin-lattice relaxation. It was found that there exists a maximum of the relaxation rate in carbon tetrachloride, and two maxima in benzene-d6 and chloroform-d, on dilution with a solvent. This relaxation behavior was attributed to the change in the self-association mechanism of acetic acid. We tried to keep the proton-density constant in all solution in order to avoid any ambiguity arising from the change in density by using the analogous deuterated compounds.
Syntheses of a New Series of Transition Metal Chelates of Diphenylphosphinothioylthiourea Anion
Authors: Ojima Iwao , Onishi Takaharu , Iwamoto Toschitake , Inamoto Naoki , Tamaru Kenzi
Published: July 2006

New thiourea derivatives, 3-diphenylphosphinothioyl-1 -phenylthiourea (PTTU-A), 3-diphenylphosphinothioyl-1,1-diethyl thiourea (PTTU-B), and 3-diphenylphosphinothioyl-1,1-dimethylthiourea (PTTU-C) were found to behave as bidentate ligands with transition metal ions such as Ni(II), Pd(II), Co(II), and Cu(II) to give a series of novel metal chelates. The structures of these complexes are discussed on the basis of magnetic susceptibilities, infrared spectra, electronic spectra, powder X-ray diffraction patterns and elemental analyses. Tentative assignments of two metal-sulfur stretching vibrations in the far infrared spectra were made for Ni-PTTU and Pd-PTTU, which have square-planar configurations. However, the structures of the Cu-PTTU complexes could not be determined by these methods because of the instability of the complexes. They were confirmed by electronic and ESR spectroscopies.
Some Displacement Reactions of Neopentyl Type Bromide Derived from Thujopsene
Authors: Ito Masaaki , Abe Kazuo , Takeshita Hitoshi , Yatagai Mitsuyoshi
Published: July 2006

The reaction of thujopsene with gaseous hydrogen bromide at low temperature affords a 48% yield of neopentyl type bromide. The reactivity of the homoallyl bromide was inspected. First, the neopentyl type bromide was derived to a diethyl widdryl malonate in order to demonstrate the reaction which indicates the involvement of homoallylcyclopropylcarbinyl ion system. The malonate was converted to a carboxylic acid and then to isomeric lactone. To demonstrate the reaction which suggests the retention of carbon frame work in the reaction, the reaction of the neopentyl bromide was extended to Grignard reaction. The Grignard reagent reacted with cyclohexanone gave a tertiary alcohol, whereas a dimeric hydrocarbon was also obtained through the Wurtz type condensation. The tertiary alcohol was converted to a dehydrated hydrocarbon and then a glycol.
Electronic Structure of Lone Pairs. III. H2S2, H2O2, N2H4, and Diimides
Authors: Yamabe Hiroko , Kato Hiroshi , Yonezawa Teijiro
Published: July 2006

The electronic structure, the electronic transition, and the interaction of lone pairs of H2S2, H2O2, and N2H4 for several dihedral angles are studied by the semi-empirical ASMO SCF method, and their dependencies on the dihedral angle is discussed. Also, the interaction of the lone pairs of diimides, N2H2, N2F2, and (CH3)2N2, the relative stability of the cis forms and of their trans form, and the electronic transition energies of these molecules are calculated. The stable forms of N2H2 and (CH3)2N2 are calculated to be of the trans form, but that of N2H2 is the cis form. An energy component analysis of these compounds has been made. The main factor in the lack of stability of the cis form of N2H2 is shown to be the core-core repulsion term, Vnn. On the other hand, in H2S2 and N2H4 not only the Vnn term but also the electrostatic interaction term, \oversetocc\underseti,jΣ(2Jij−Kji), contributes to their instability.
Cleaning Effects of the Reactant in the Liquid-phase Isomerization of m-Xylene over a Silica-Alumina Catalyst under Pressure
Authors: Takaya Haruo , Todo Naoyuki , Hosoya Tadasuke , Minegishi Toshio , Yoneoka Mikio , Oshio Hideki
Published: July 2006

The activity of silica-alumina catalyst in the isomerization of m-xylene was measured at the temperatures of 290°C, 320°C, 380°C, and 430°C in the liquid phase under a pressure of 300 kg/cm2. The observed activities were considerably higher than those in vapor-phase reactions, moreover even after 20 days practically no decline in the activity was observed except for the measurements at 430°C. This superior ability of the catalyst in the liquid phase can be ascribed to the cleaning effect of the liquid reactant: in the liquid-phase reaction the high-boiling by-product, which, in vapor-phase reactions, diminishes the activity because of its strong adsorptivity on the surface sites, is successively dissolved in the reactant; therefore, more surface sites are constantly available for the isomerization. This interpretation was substantiated by the following results: 1) when the reaction was operated in the liquid phase, about eighteen times as much high-boiling by-product was obtained as in the vapor phase; 2) the activity in the liquid-phase reaction was much higher than that in the vapor phase; 3) the decreased activity caused by the interruption of the flow was regenerable when the flow was resumed; 4) the addition of the high-boiling by-product to the reactant m-xylene resulted in a considerable decrease in the activity. In addition, the identification of the components in the high-boiling by-products was carried out by means of mass and NMR spectroscopic studies.
Topological Index. A Newly Proposed Quantity Characterizing the Topological Nature of Structural Isomers of Saturated Hydrocarbons
Authors: Hosoya Haruo
Published: July 2006

A topological index Z is proposed for a connected graph G representing the carbon skeleton of a saturated hydrocarbon. The integer Z is the sum of a set of the numbers p(G,k), which is the number of ways in which such k bonds are so chosen from G that no two of them are connected. For chain molecules Z is closely related to the characteristic polynomial derived from the topological matrix. It is found that Z is correlated well with the topological nature of the carbon skeleton, i.e., the mode of branching and ring closure. Some interesting relations are found, such as a graphical representation of the Fibonacci numbers and a composition principle for counting Z. Correlation of Z with boiling points of saturated hydrocarbons is pointed out.
Molecular Structure of Piperazine as Studied by Gas Electron Diffraction
Authors: Yokozeki Akimichi , Kuchitsu Kozo
Published: July 2006

A study of piperazine by means of gas electron diffraction has given the following structural parameters (the rg distances and the angles based on the rα structure) with estimated limits of error: C–C=1.540±0.008 Å, C–N=1.467±0.004 Å, ∠C–C–N=110.4±0.8°, ∠C–N–C=109.0±0.8°, C–H=1.110±0.008 Å and ∠H–C–H=109·1±5°; the molecule takes a chair conformation. The C–C distance is nearly equal to that in cyclohexane, and the C–N–C angle is slightly smaller than the C–C–N angle. These angles agree with those predicted by an SCF-CNDO/2 method.
A Fermi Resonance with ν6 of Acetonitrile
Authors: Matsuura Hiroatsu
Published: July 2006

The rotation-vibration spectrum of ν6 of acetonitrile measured by Nakagawa et al. has been reanalyzed by taking account of the Fermi resonance between the states |v6=1> and |v7=1, v8=1>. The previous assignment of Q branches by Amat et al. has been revised on the basis of the obtained values of band constants. The following band constants have been determined for the ν6 band: ν0=1447.9 cm−1, ζ=−0.305 and αA=0.046 cm−1. From the value of the resonance operator, the magnitude of the cubic force constant k678 has been estimated to be about 30 cm−1.
The Ruthenium-Catalyzed Hydrogenation of Aromatic Amines Promoted by Lithium Hydroxide
Authors: Nishimura Shigeo , Kono Yutaka , Otsuki Yoshiharu , Fukaya Yoshio
Published: July 2006

The effects of the addition of various alkaline substances on the ruthenium-catalyzed hydrogenation of aromatic amines have been investigated at raised temperature and pressure. The addition of lithium hydroxide was shown to be the most effective for rapid and selective hydrogenation of aromatic amines. The effect of various solvents on the hydrogenolysis of carbon-nitrogen bonds has also been studied in the hydrogenation of m-xylene-α,α′-diamine and N,N-dimethyl-p-phenylenediamine. Generally, the hydrogenation was fast and the amount of the hydrogenolysis was small in secondary alcohols. Typical examples of the syntheses of alicyclic amines are given.
The Chemical Behavior of Low Valence Sulfur Compounds. VII. The Oxidation of Ammonium Sulfide and Ammonium Sulfite with Compressed Oxygen in Aqueous Ammonia Solution
Authors: Naito Kunishige , Okabe Taijiro
Published: July 2006

The oxidation of ammonium sulfide and ammonium sulfite with compressed oxygen in aqueous ammonia soultion was studied in order to confirm the formation of ammonium sulfamate. Ammonium sulfite is easily oxidized to ammonium thiosulfate through polysulfides with oxygen and further to ammonium sulfamate and ammonium sulfate. Suitable conditions for producing ammonium sulfamate were found to be: initial concentration of ammonium sulfide 2.0 mol/l, temperature 100°C, concentration of ammonia 12 mol/l, concentration of cupric ion 0.1 mol/l and oxygen pressure 50 kg/cm2. Though ammonium sulfite is wholly oxidized to ammonium sulfate under the same conditions, it is partially oxidized to ammonium sulfamate besides sulfate in the presence of cupric ion under high concentration of ammonia. The mode of oxidation might differ from that of ammonium thiosulfate, ammonium sulfide and elemental sulfur because of no formation of polythionate as an intermediate.
Charge-Transfer Interaction and Fluorescence in Some Tetracyanobenzene Complexes
Authors: Kobayashi Takayoshi , Yoshihara Keitaro , Nagakura Saburo
Published: July 2006

Fluorescence lifetimes and quantum yields were measured for some tetracyanobenzene complexes with benzene and its methyl derivatives, and the radiative and nonradiative rate constants were determined under various conditions. The results show that the low fluorescence intensities of the complexes in nonpolar fluid media are due to small radiative rate constants and that nonradiative processes become important for the complexes in polar fluid media. From the theoretical consideration of the observed radiative transition probability, it is found that the geometry and the charge distribution in the excited equilibrium state are greatly different from those in the excited Franck-Condon state for the complexes in fluid media at room temperature and that the degree of the charge-transfer in the former state amounts to 96–100%, while it is only 12–45% in the latter state. The stabilization energy due to the reorientation was obtained from the temperature dependence of the fluorescence spectrum.
Effects of para-Substituents on the Rates of Inversion of Biphenyl Derivatives. I. 5,7-Dihydrodibenzo[c,e]thiepins
Authors: Oki Michinori , Iwamura Hiizu , Yamamoto Gaku
Published: July 2006

Several 3,9-disubstituted 5,7-dihydrodibenzo[c,e]thiepins were synthesized and temperature dependence of their NMR spectra was examined. All the substituted derivatives showed a lower energy barrier to inversion than the unsubstituted one. The effects of the substituents on the energy barrier may be interpreted in terms of resonance stabilization and/or out-of-plane bending of the axis bond at the transition state.
Molecular Structure and Phase-shift of Tetramethyllead as Studied by Gas Electron Diffraction
Authors: Oyamada Takeo , Iijima Takao , Kimura Masao
Published: July 2006

The molecular structure of tetramethyllead has been determined by the sector-microphotometer method of gas-phase electron diffraction. The structure parameters determined by a least-squares analysis on molecular intensities are, with estimated limits of error, as follows; rg(Pb–C)=2.238±0.009 Å, rg(Pb–H)=2.72±0.06 Å, rg(C···C)=3.66±0.07 Å, and rg(C–H)=1.08±0.02 Å. The experimental cut-off point was nearly 37 in q value for the 42.0 keV electrons; this was not in sufficient agreement with the theoretical value as calculated from the Thomas-Fermi-Dirac potential for Pb and from the Hartree-Fock potential for C. Moreover, the experimental background showed a significant deviation from its theoretical counterpart in the region of small q values. This discrepancy has not been accounted for even by the use of scattering factors based on a relativistic SCF calculation, or by the correction for the polarization effect available at present.
Molecular Structure of Dimethyltin Dichloride as Studied by Gas-electron Diffraction
Authors: Fujii Hideji , Kimura Masao
Published: July 2006

The molecular structure of dimethyltin dichloride was determined by the sector-microphotometer method of electron diffraction to be as follows: rg(Sn–Cl)=2.327±0.003 Å, rg(Sn–C)=2.108±0.007 Å, and rg(C–H)=1.113±0.020 Å, and all the valency angles were near 109.5°. In comparison with the Sn–Cl distances in the series of Sn(CH3)4−nCln, as determined previously by the same method, a regular bond contraction in going from Sn(CH3)3Cl to SnCl4, as pointed out previously by Skinner and Sutton, was ascertained.
Effects of para-Substituents on the Rates of Inversion of Biphenyl Derivatives. II. 2-Isopropyl-2′-methoxybiphenyls
Authors: Oki Michinori , Yamamoto Gaku
Published: July 2006

Nine 4,4′-substituted 2-isopropyl-2′-methoxybiphenyls were synthesized and temperature dependence of the NMR spectra of these compounds was examined. The effects of the substituents on the energy barrier to inversion of the biphenyl skeleton can be interpreted in terms of both resonance stabilization and out-of-plane bending of the axis bond at the transition state. In the latter, an electron-donating substituent makes the bond bendig easier and lowers the barrier, whereas an electron-withdrawing group raises the barrier.
Correlation between the Transition Temperature and the Rotational Potential Barrier in Plastic Crystals
Authors: Chihara Hideaki , Koga Yoshikata
Published: July 2006

A linear retationship was found between the transition temperature of plastic crystals and potential energy barrier hindering molecular rotation determined below or above the transition point, with the slope of the line 7.5 R and 4.1 R, respectively, where R is the gas constant. Consideration of the distribution of molecules between the librational and the rotational states showed that the transition starts to occur cooperatively when the fraction of the rotating molecules reaches a value of 1/60 and concludes with a value of 1/3. The model gives the entropies of transition which reasonably agree with the observed values.
Gas Chromatography of Aluminum, Gallium, and Indium β-Diketone Chelates
Authors: Utsunomiya Kei
Published: July 2006

The gas-chromatographic behavior of aluminum(III), gallium(III), and indium(III) chelates with various β-diketones was investigated. The β-diketones studied were acetylacetone and 8 synthesized, alkyl-substituted acetylacetones, benzoylacetone, dibenzoylmethane, trifluoroacetylacetone and its 5 synthesized alkyl derivatives, hexafluoroacetylacetone, benzoyltrifluoroacetone, furoyltrifluoroacetone, and thenoyltrifluoroacetone. The trifluoromethyl group increases the volatility of the chelates, while the aromatic group tends to decrease the volatility. In the alkyl-substituted acetylacetone series, the retention time of the chelates increases with an increase in the molecular weight, but it does not depend upon the volatility. On the other hand, the retention of the chelates containing the trifluoromethyl group is almost inversely correlated with the volatility.
The Determination of the Amount of Oxygen in Molten Copper-Nickel and Copper-Silver Alloys by the EMF Method
Authors: Tsukahara Iwao
Published: July 2006

Using the following solid oxide-electrolyte galvanic cells, Pt/air//ZrO2 (+CaO) O//(in Cu–Ni alloy)/Mo and Pt/air//ZrO2 (+CaO) O//(in Cu–Ag alloy)/Mo, the electromotive forces of the cells have been measured as a function of the oxygen concentration in copper-nickel or -silver alloys at oxygen concentrations ranging from several ppm to 1000 ppm, at 1210°C for copper-nickel alloys and at 1100°C or 1200°C for copper-silver alloys respectively. The activity coefficient of oxygen has been determined from the electromotive force for the alloy systems investigated. In the case of copper-nickel, the activity coefficient of oxygen decreases with an increase in the nickel concentration and also with a decrease in the oxygen concentration. The solubility of oxygen in the copper-nickel alloy has also been measured at 1210°C by the use of the following galvanic cell, Pt/air//ZrO2(+CaO)//O(in Cu–Ni alloy), NiO/Mo.
Electrolyses of 2,2-Dichloro-3-phenylcyclopropanecarboxylic Acids in Hydroxylic Solvents with a Platinum Anode
Authors: Takeda Akira , Wada Satosi , Murakami Yasuo
Published: July 2006

Electrolysis of 2,2-dichloro-3-phenylcyclopropanecarboxylic acid (1a) in hydroxylic solvents such as methanol and acetic acid, or in aqueous methanol with acetic acid in excess, was carried out with a platinum anode. Solvolysis rather than coupling was found to occur yielding 3,3-dichloro-1-phenylallyl methyl ether (4a) or 3,3-dichloro-1-phenylallyl acetate (5a), or both, depending on the solvent. Electrolysis of 2,2-dichloro-3-methyl-3-phenylcyclopropanecarboxylic acid (1b) in aqueous methanol gave ether 4b. Structural characterization of the products was also discussed.
Chemical Constituents of Alnus sieboldiana (BETULACEAE) II. The Isolation and Structure of Flavonoids and Stilbenes
Authors: Asakawa Yoshinori
Published: July 2006

Four new flavonoids with an unsubstituted B-ring, alnusin, alnetin, alnustin, and alnustinol, isolated from Alnus sieboldiana were established to be 3,5,7-trihydroxy-6-methoxyflavone (1), 5-hydroxy-6,7,8-trimethoxyflavone (2), 5-hydroxy-3,6,7-trimethoxyflavone (3), and 3,5,7-trihydroxy-6-methoxyflavanone (15) respectively. Some previously-known flavonoids, chrysin (4), izalpinin (5), tectochrysin (6), pinocembrin (16), pinobanksin (17), strobopinin (19) and naringenin (20), and some stilbenes, pinosylvin (24), pinosylvin monomethyl ether (25), and pinosylvin dimethyl ether (26), were identified along with the above new flavonoids.
The Crystal and Molecular Structure of Miyaconitine Hydrobromide Dihydrate
Authors: Shimanouchi Hirotaka , Sasada Yoshio , Takeda Tatsumichi
Published: July 2006

The structure of an Aconitum alkaloid, miyaconitine, C23H29O6N, has been determined by the X-ray analysis of crystals of the hydrobromide dihydrate, which are monoclinic with four formula units in a unit cell of the dimensions; a=10.41, b=13.85, c=9.63 Å and β=113.8°; space group, P21 The structure was solved by the heavy-atom method and was refined by the least-squares method. The final R index was 0.151. The absolute configuration was determined using the anomalous dispersion effect of the bromine atom. It was thus established that miyaconitine is a novel type of Aconitum alkaloid.
The Reactions of Grignard Reagents with Transition Metal Halides: Coupling, Disproportionation, and Exchange with Olefins
Authors: Tamura Masuhiko , Kochi Jay K
Published: July 2006

The reactions of transition metal halides (Mn, Fe, Co, Ni, Pd, Cu, and Ag) with the low-molecular-weight alkyl Grignard reagents in tetrahydrofuran and diethyl ether, especially in the presence of styrene were reinvestigated. An alkyl transition metal species formed in situ by metathesis decomposed to a dialkyl (oxidative dimerization) or to an alkene and an alkane (oxidative disproportionation). Silver(I) and copper(II) were particularly effective in oxidative dimerization of primary alkyl groups. Alkyl groups which contain no β-hydrogen were also coupled by iron, cobalt, nickel, palladium, and copper(I) halides with varying degrees of efficiency. Oxidative disproportionation was generally the more common route to decomposition for alkyl groups which have β-hydrogens. It seemed to proceed directly via a bimolecular interaction of alkylmetals or indirectly by elimination of a hydrido-metal species. If the latter added to an alkene reversibly, exchange was observed between Grignard reagent and alkene. Styrene was reduced to ethylbenzene during the reaction both in tetrahydrofuran and in diethyl ether in varying yield with transition metal halide and Grignard reagent. In addition to alkyl exchange, dehydrogenation of the ethereal solvent by active (reduced) metal species complicated the stoichiometry of decomposition as measured by the value of the empirical parameter, Q,(R). The selection of transition metal in addition to the temperature, solvent and triphenylphosphine was effective variables in promoting the efficiency of the exchange process.
Imidazole Catalyses in Aqueous Systems. VIII. Spontaneous Hydrolysis and Michaelis-Menten-type Catalytic Hydrolysis of Phenyl Esters in the Presence of Cholic Acid and Its Histamine Derivative
Authors: Shinkai Seiji , Kunitake Toyoki
Published: July 2006

Spontaneous hydrolyses of cationic and anionic phenyl esters in the presence of cholic acid (VI) and their catalytic hydrolyses with a histamine amide of cholic acid (VII) were investigated using a pH-stat at 30°C in 1.0m aqueous KCl. The rates of spontaneous hydrolysis decreased by 30–70% upon binding of substrates with cholic acid. The variation of the apparent binding constant (7-3650m−1) was considered to reflect the magnitude of hydrophobic forces between cholic acid and substrates, although the values may have to be corrected for the possible involvement of self-association of cholic acid molecules. Imidazole derivative VII catalyzed the hydrolysis of phenyl esters according to Michaelis-Menten kinetics. The long methylene chain in the substrate molecule contributed appreciably to the binding of substrate with cholic acid and its derivative. The magnitude of substrate binding with VII appears to be comparable to the true binding constant with cholic acid. The intracomplex rate constants did not differ much from those expected with other enzyme-like catalysts. Thus, the steroid ring seems to provide a non-specific hydrophobic binding site for the substrates used.
The Conversion of Some Alkylxanthates to the Corresponding Trithiocarbonates. The Nucleophilic Reaction of −SCSSR
Authors: Yoshida Hiroshi , Ogata Tsuyoshi , Inokawa Saburo
Published: July 2006

The reaction of O-methyl-, ethyl-, and benzylxanthates with a catalytic amount of triethylamine in the presence of excess carbon disulfide gave the corresponding trithiocarbonate in good yields. The products were formed by the nucleophilic reaction of −SCSSR with xanthates. The kinetic study showed the following order of nucleophilicity toward xanthates in DMF:

−SCOSMe>−SCSSMe>Me3N
Studies of the Synthesis of Furan Compounds. XXV. 2-[2-(5-Nitro-2-furyl)-1-(4-cyanophenyl)vinyl]-1,3,4-oxadiazoles and -1,3,4-thiadiazoles
Authors: Hirao Ichiro , Kato Yasuhiko
Published: July 2006

5-Amino-2-[2-(5-nitro-2-furyl)-1-(4-cyanophenyl)vinyl]-1,3,4-oxadiazoles and -1,3,4-thiadiazoles have been synthesized from 3-(5-nitro-2-furyl)-2-(4-cyanophenyl)acrylic acid according to a procedure previously described. All of these compounds exhibit strong antibacterial activity against Staphylococcus aureus, but they exhibit a weak activity, or almost no activity, against the other microorganisms tested.
Conformations of the Esters. II. The Conformation of Alkyl Acetates
Authors: Oki Michinori , Nakanishi Hiroshi
Published: July 2006

Alkyl acetates which carry secondary and tertiary alkyl groups have been found to have bifurcated bands in the carbonyl region of the infrared spectra. The origin of the bifurcated bands has been studied carefully, and it has been concluded that the Fermi resonance is the most probable origin of the phenomenon.
Photolytic and Thermal Decompositions of 5-Substituted 1,2,3,4-Thiatriazoles in the Presence of Olefins. Reactions of Sulfur Atoms
Authors: Okazaki Renji , Okawa Kazumi , Wajiki Seiji , Inamoto Naoki
Published: July 2006

Photochemical decompositions of 5-phenyl- and 5-amino-1,2,3,4-thiatriazoles in the presence of cyclohexene or tetramethylethylene led to the formation of the corresponding episulfide, the production of which has been explained in terms of sulfur atom reactions with the olefins. Kinetic measurements revealed the limitation of the reactions as a synthetic method of an episulfide from an olefin. Mechanism of the episulfide formation was briefly discussed. Thermal decompositions of these thiatriazoles in the presence of olefins gave rise to no episulfides.
On the Factors Determining the Molecular Arrangement in Crystalline Ethylene
Authors: Hashimoto Masao , Hashimoto Michiko , Isobe Taro
Published: July 2006

The orientation-dependent potential energy of the ethylene crystal was calculated using a somewhat modified expression for the dispersion energy in the case of non-axially symmetric molecules. It was concluded that the main force which determines the angle between the bc plane and the C=C bond axis in the ethylene crystal is the dispersion; on the other hand, it is the quadrupole-quadrupole interaction which determines the angle between the ab plane and the C=C bond axis. The expected molecular arrangement in the crystalline ethylene belongs to the space group P21/n, this is consistent with the conclusion obtained from the spectroscopic data.
Solvent Effect on the Vibrational Structures of the Fluorescence and Absorption Spectra of Pyrene
Authors: Nakajima Akira
Published: July 2006

The anomalously large Ham effect observed in pyrene has been studied in various solvents at room temperature by measuring the fluorescence and absorption spectra. As in the case of benzene, the Ham bands of pyrene were assigned to the 0–0 and ag-vibration bands. This was confirmed by fluorescence polarization measurement. The correlation of the intensities of the fluorescence and absorption bands to solvent polarities is discussed.
The Catalytic Dehydrohalogenation of Haloethanes on Solid Acids and Bases
Authors: Mochida Isao , Anju Yasuhide , Yamamoto Hiroko , Kato Akio , Seiyama Tetsuro
Published: July 2006

The elimination reactions of haloethanes and halopropanes on solid acids and bases, including a series of metal sulfates supported by silica gel, were studied at 300°C by means of the pulse technique in order to clarify the mechanism of the catalytic dehydrohalogenation. The trans-1,2-dichloroethylene/cis-1,2-dichloroethylene (trans-1,2/cis-1,2) selectivities from 1,1,2-trichloroethanes as well as the activities of the metal sulfates supported by silica gel were well correlated with the electronegativities of the metal ions. Generally speaking, the rates of the dehydrochlorination from chloroalkanes were nearly equal to those of the dehydrobromination from bromoalkanes on the solid acids, but the latter were larger than the former on solid bases. The reactivities of the alkylhalides on solid acids and bases were examined from the electronic view-point, and we tried to correlate them with some reactivity indexes. A kinetic isotope effect with regard to hydrogen was observed on solid bases, but not on solid acids, in the dehydrobromination of 1,2-dibromoethane. From these facts, it was concluded that the dehydrohalogenation proceeds through a carbonium-ion mechanism on solid acids and via an E2 step-by-step mechanism on solid bases.
Theoretical and Experimental Considerations of the Direct Photo-Isomerization and Chemistry of 1,3-Pentadiene
Authors: Inuzuka Kozo , Becker Ralph S
Published: July 2006

Potential energy curves as a function of the angle of twist around single and double bonds have been calculated for piperylene (1,3-pentadiene). Also, direct-excitation cis→trans photoisomerization and trans→methycyclobutene photochemistry have been investigated as a function of the temperature. The theoretical analysis strongly indicates that the cyclobutene is formed photochemically from the trans-s-cis isomer which is created thermally from the trans-homer in the ground state (not by photoisomerization). The temperature-dependency data support this conclusion. The theoretical data also indicate that there is a small barrier to photoisomerization around the double bond in the first excited singlet (and triplet) state. The temperature-dependency data also support this conclusion. The potential energy curves are in harmony with the known emission (none exists), photoisomerization, and internal-conversion data for the cis- and trans-piperylenes. The emission properties of model cyclic diene steroids are compared with those expected from linear dienes, and the emission results of the former are interpreted within the theoretical framework developed.
Metal Complexes with Amino Acid Amides. III. Geometrical Structures and Electronic Spectra of Bis(α-amino-acid-amidato)palladium(II), nickel(II) and Copper(II)
Authors: Komorita Takashi , Hidaka Jinsai , Shimura Yoichi
Published: July 2006

Square planar complexes of [ML2] type were synthesized, where M=Pd2+ and Ni2+ for L=l-valine-, l-phenylalanine- and l-proline-amidate anions, and M=Pd2+, Ni2+ and Cu2+ for L=l-leucinemethylamidate anion and for L2=trimethylenediamine-N,N′-diisobutyric acid amidate dianion; the last ligand is a tetradentate one and gives exclusively cis type complexes. Cis and trans isomers were isolated and identified for each of the l-valinamidato and the l-prolinamidato palladium complexes. All the other complexes were inferred to be trans isomers from examination of the electronic absorption and circular dichroism spectra. Common solvent effects of the ligand field bands were clearly observed between the trans palladium and trans nickel complexes. A similar empirical relationship was also found between the ligand field bands of the trans palladium complexes and those of the corresponding cis isomers. The spectral behavior of the bis(l-amino-acid-amidato)-copper(II) complexes was not so easily related to that of the corresponding nickel or palladium complexes. The ligand field bands of the palladium, nickel, and copper complexes were tentatively assigned.
Infrared Absorption Spectra and Normal Coordinate Analysis of Metal-Dl-α-Serine Chelates
Authors: Inomata Yoshie , Inomata Tadaaki , Moriwaki Takao
Published: July 2006

The infrared absorption spectra of Dl-α-serine and four metal-Dl-α-serine chelates have been investigated from 4000 to 200 cm−1. A normal coordinate analysis has been accomplished for the metal chelates as a 27-body problem and an approximate description of the vibrational mode has been assigned to the observed frequencies. The frequency separation between carboxylate antisymmetric and symmetric stretching vibrations and values of the bond-stretching force constants for the metal-nitrogen bonds have been found to decrease in the order Pt(II)>Pd(II)>Cu(II)>Ni(II). These facts show that the hydroxy group in the β-position of Dl-α-serine has no influence on the order of metal-ligand bond strength, which order has been already found in aliphatic α-amino acids chelates having no hydroxy group in the β-position. Two species of copper chelates have been prepared. Though the infrared spectrum of one of them is similar to that of the nickel(II) chelate, that of the other species is different. This fact may be explained by assuming that the copper ion has been coordinated with the hydroxy group in the latter.
Inclusion Compounds of Some Charge-Transfer Complexes
Authors: Ohmasa Masatake , Kinoshita Minoru , Akamatu Hideo
Published: July 2006

The charge-transfer complex of benzidine and tetracyano-p-quinodimethane has been shown to form an inclusion compound with certain molecules such as dichloromethane, dibromomethane and acetone. The molecular volumes of these guest substances are all smaller than 75 cm3/mol, while the substances which are not included have a molecular volume larger than 80 cm3/mol. Besides the size, the molecular shape is also considered to be a primary factor for the formation of the inclusion compound. The heat of formation of the inclusion compound with dichloromethane as a guest was determined to be 11.1±1 kcal per mole of the guest substance by the thermochemical measurements. Similar inclusion compounds were also obtained, when 3,3′-diaminobenzidine, 3,3′-dichlorobenzidine and o-tolidine were used in place of benzidine.
Electronic Properties of Benzidine·TCNQ System
Authors: Ohmasa Masatake , Kinoshita Minoru , Akamatu Hideo
Published: July 2006

The benzidine·tetracyano-p-quinodimethane (TCNQ) system forms two types of charge-transfer complexes; one (I) containes some sort of solvent molecules, while the other (II) does not. The electronic properties of I have been found to be unusual in many respects compared to II which shows the properties expected from those of ordinary charge-transfer complexes. I and II did not exhibit ESR absorption, if they were well-grown crystals. However, when they were pulverized to fine powder, I showed a strong absorption while II did not. The visible range absorption spectra of I and II consisted of three main bands, but all the bands of I were found to be shifted to longer wavelengths compared to those of II. In addition to these bands, two shoulders were found in the spectrum of I. The shoulders were considered to be due to the ion radicals produced from benzidine and TCNQ. The electrical resistivities are again quite different from one another. The resistivity of I was found to be 103–105 ohm cm at room temperature, the value being dependent on the kind of the solvent molecules included, while that of II was 2×109 ohm cm. The activation energy for conduction was smaller for I (0.1–0.2 eV) than for II (0.34 eV).
Distribution of Nickel across the Thickness of Al Anodic Oxide Films Sealed in Nickel Sulphate Solutions
Authors: Campanella Luigi
Published: July 2006

The distribution of nickel across the thickness of Al anodic oxide films, produced in 15.5% w/v H2SO4 as electrolyte and sealed in nickel sulphate solutions, is determined and an approximate confirmation of the conical shape of pores is obtained.
The Effect of Consecutive Complex Formation on the Separation of Rare Earths by Electromigration
Authors: Ohyoshi Emiko
Published: July 2006

The effect of a complexing agent with which rare earths consecutively form complexes on the separation of an adjacent pair of rare earths by electromigration was investigated. By assuming the complexes ML and ML2 to be formed, the relation of the separation factor, the difference in the zone mobility of the two rare earths, to the ligand-ion concentration was derived and examined for the separation of the La-Ce and Ce-Pr pairs by using nitrilotriacetic acid (NTA), which is known to form the ML and ML2 complexes with rare earths. It is found that the separation factor is affected not only by the difference in the first (k1) or the second (k2) consecutive formation constant of the two elements to be separated, but also by the value of the k1/k2 ratio.
Studies of the Synthesis of Furan Compounds. XXII. Synthesis and Antibacterial Activity of 5-[2-(5-Nitro-2-furyl)-1-(2-furyl)vinyl]-2-amino-1,3,4-thiadiazole and Its Related Compounds
Authors: Kato Yasuhiko
Published: July 2006

In continuing our study of the relationship between structures and antibacterial activity, 5-[2-(5-nitro-2-furyl)-1-(2-furyl)vinyl]-2-amino-1,3,4-thiadiazole and related derivatives have been synthesized. Their structures were confirmed by their chemical reactions and by their UV, IR, and NMR spectra. 1,3,4-Thiadiazole and its related derivatives show significant antibacterial activity.