bluuebunny/crossref_metadata_2025 huggingface dataset:
The Study of the Raman Band Shape of Sulfuric Acid and Proton Transfer
Authors: Ikawa Shun-ichi , Kimura Masao
Published: July 2006

The Raman bands of sulfuric acid and ammonium sulfate in aqueous solutions were observed in the S–O stretching region and were resolved into components with a Voigt profile. The concentration dependence of the half band-widths was examined. The 980 cm−1 band of SO42− in acidic solutions was determined to have a width of 8.0±0.3 cm−1 when unbroadened by any chemical process. In the concentration-half-width curve for this band, two conspicuous bends were found, at about 2 M and 8 M stoichiometric concentrations of H2SO4. It seems that the former bend is attributable to the disappearance of water clusters, and the latter, to the partial defect of the primary hydration shell of the oxonium ion. The interrelation between the half-widths of the 980 cm−1 and 1050 cm−1 bands suggests that the formation of the HSO4−·H3O+ ion pair is related to the spectroscopic lifetime of HSO4−.
Electric Dipole Moment of 4-Chloro-2,3-tetra-, penta-, and hexamethylene Quinoline
Authors: Dipti Miss , Rastogi Pushti Prakash
Published: July 2006

Electric dipole moments of 4-chloro-2,3-tetra-, penta-, and hexamethylene quinolines have been determined in benzene solution at a frequency of 1 MHz by Guggenheim method. The reported results indicate that these compounds are non-planar and the dipole moment increases with the increase in the size of substituted methylene ring.
Stability of Dextran Solutions
Authors: Aizawa Masuo , Suzuki Shuichi , Kuoka Tatuo , Nakajima Noriyasu , Iwao Yutaka
Published: July 2006

In order to clarify the accessibility of dextran to both water and dextran the onset of turbidity in dextran solution was studied by means of viscosimetry and near-infrared and PMR measurements. Mole fraction of monomeric and hydrogen-bonded water species in dextran solutions were calculated for various concentrations of dextran solutions from 2ν1+ν3 and ν1+ν2+ν3 bands where ν1, ν2, and ν3 are the fundamental vibrations of symmetric stretching, bending and asymmetric stretching, respectively. The extent of hydrogen bonds was estimated from PMR chemical shift of water proton. A dextran solution was characterized by a low concentration in monomeric water. An anomalous time dependence of viscosity and PMR chemical shift was observed for concentrated solutions. A mechanism has been proposed for gelation and the onset of turbidity, stress being laid on comparable accessibility of dextran to both water and dextran.
Temperature Dependence of the Dielectric Constants of Potassium-Chloranil Salt and Würster’s Blue Perchlorate
Authors: Ishii Kikujiro , Kaneko Katsumi , Kuroda Haruo
Published: July 2006

The dielectric constants of potassium-chloranil salt(K+CA−) and Wiirster’s blue perchlorate (WBP) were measured around their phase-transition temperatures in the X-band microwave region. In the case of K+CA−, a sudden increase in the dielectric constant was observed accompanying a change to the low-temperature phase. This is interpreted to arise from the change in electronic polarization associated with a marked increase in the intensity of the charge-transfer band in the near-infrared region. An anomalous peak and associated gradual changes were observed in the temperature dependence of the dielectric constant of WBP around the phase transition temperature. The difference in dielectric behavior of these two cases is discussed in relation to the optical absorption spectra and other properties of the crystals.
Lactone Carboxylic Acids. VIII. A Synthesis of γ-Substituted α-Aminobutyrolactones from Ethyl γ-Substituted α-Hydroxyaminoaconates
Authors: Torii Sigeru , Ukida Masasi , Kano Hiromichi , Furuta Takuya , Tanaka Hideo
Published: July 2006

The conversion of α-hydroxyaminoaconates 1a and 1b to α-aminoaconates 2a and 2c was described, involving a novel reduction of the α-hydroxyamines on treatment with p-toluenesulfonyl chloridep–yridine in 62.1–89.5% yields. In the case of the reduction of 1b  N-tosyloxy derivative 11b was isolated. α-Amino-γ-butyrolactones 3 and 4 could be obtained by hydrogenation of N-acetates of 2a and 2c. Ammonolysis of 2-hydroxy-2-butenolides 5a and 7a prepared from acid-hydrolysis of 1b also gave α-aminobutyrolactones 6, 8a, 8b, 9, and 10.
The Coordinative Behavior of the Ethereal Oxygen Atom in Cobalt, Nickel and Copper Complexes with Schiff Bases Obtained from Salicylaldehyde Derivatives and 2-(Aminomethyl)furan
Authors: Yamada Shoichiro , Yamanouchi Kuniko , Mori Wasuke , Kishita Michihiko
Published: July 2006

Cobalt(II), cobalt(III), nickel(II), and copper(II) complexes with N-(2-furylmethyl)salicylideneaminates (abbreviated as X–sal–fum) were synthesized. In addition to the M (X–sal–fum)2 type complexes, those of the formula Cu (X–sal–fum) Cl were obtained in crystals. The complexes Co (X–sal–fum)3 are six-coordinate, octahedral. The cobalt(II) complex is four-coordinate, tetrahedral and the nickel(II) complexes are four-coordinate, planar. In these complexes, the ligands X–sal–fum function as bidentates, the furan oxygen atom not being bound to the metal ions. The results are compared with those reported previously for related ligands. It is most likely that the complexes Cu(X–sal–fum)Cl consist of binuclear complexes with spin-spin interaction between copper(II)ions.
Stereoselectivities in Mixed Ligand Complexes of Cobalt(III), with l-Asparagine as a Ligand
Authors: Takenaka Hideto , Shibata Muraji
Published: July 2006

The [Co(ox)(l-aspNH2)(en)] complex as well as the [Co(l-aspNH2)3−n(l-asp)n]n− complexes (n=1,2) have been prepared and separated into their diastereoisomers by means of column chromatography. The structures of the isomers thus isolated have been characterized by their absorption, CD, and PMR spectra. Stereoselectivity in the [Co(ox)(l-aspNH2)(en)] complex has been found for the fac-Λ and mer-Δ isomers, and those in the [Co(l-aspNH2)3−n(l-asp)n]n− complexes, for the fac-Δ and mer-Λ isomers. These results have provided proof of the stereoselective effect due to the chelated l-aspar aginate ion.
Free Radicals Produced by γ Irradiation of Nitroalkanes in Frozen Glassy Acidic Solutions
Authors: Shiotani Masaru , Forchioni Alain , Chachaty Claude
Published: July 2006

The scavenging of paramagnetic species by nitroalkanes formed during the γ irradiation of aqueous 6.4 molar sulfuric acid glasses has been studied by using ESR. Nitroalkanes give rise to RNO2H radiclas, the nitrogen hyperfine coupling of which has the values A⁄⁄N=48 G and A⊥N=18 G with g⁄⁄=2.0035 and g⊥=2.0075. The RNO2H yields for 0.5 molar solutions of nitromethane and 2-nitro-2-methyl-propanol are G\simeq4 and G\simeq3, respectively. G(SO4−+OH.) is roughly idenpendent of the nitroalkane concentration. These results are interpreted as the scavenging of hydrogen atoms due to the energetic recombination of non-hydrated primary species (H2O+, OH., e−) according to an assumption of Hamill.
Semiempirical Molecular Orbital Considerations of the Electronic Structures of Transition Metal Complexes. I. Dioxygen Nickel Complexes
Authors: Tatsumi Kazuyuki , Fueno Takayuki , Nakamura Akira , Otsuka Sei
Published: July 2006

The electronic structure of Ni(O2)(HNC)2 as a model of “side-on” coordinated dioxygen nickel complexes has been investigated by the INDO method. Calculations show that the square-planar geometry is more stable than the pseudotetrahedral form in accord with the observed structure of Ni(O2)(t-BuNC)2. The central nickel atom possesses an approximately zerovalent configuration: (3d)8.5 (4s)0.5 (4P)1.0. The dioxygen-nickel bonding is effected primarily through the donation and back–donation of electrons in which the O2 πu and πg* orbitals parallel to the molecular plane participate. It is predicted that both the Ni–O and O–O bondings tend to have greater covalent bond strengths as the electron-attracting ability of the ligand isocyanide increases. Attempts are made to assign the electronic spectra.
Semiempirical Molecular Orbital Considerations of the Electronic Structures of Transition Metal Complexes. II. Acetylene- and Azo-Nickel Complexes
Authors: Tatsumi Kazuyuki , Fueno Takayuki , Nakamura Akira , Otsuka Sei
Published: July 2006

The electronic structures of zerovalent nickel π complexes, Ni(HC≡CH)(HNC)2 and Ni(trans-HN=NH) (HNC)2, have been investigated by the INDO method. Both complexes are found to favor the square-planar geometry, in accord with the observed structures of Ni(C6H5C≡CC6H5)(t-BuNC)2 and Ni(C6H5N=NC6H5)(t-BuNC)2. Ni(trans-HN=NH) (HNC)2 is predicted to be more stable than Ni(cis-HN=NH)(HN)2. The increment in the C–C and N–N bond lengths effected by the complexation seems to well reflect the net effects of σ donation and π back-donation. For the isocyanide N–C bond, an approximately linear relationship is found to hold between the calculated bond index and the observed force constant. It is suggested that both the Ni–C(of acetylene) and Ni–N(of diimide) bondings tend to have greater covalent bond strengths as the electron-releasing ability of the isocyanide ligand increases.
A Systematic Study of the Yields of γ-Radiolysis Products in C1, C2, and C3-Chlorofluorocarbons
Authors: Tominaga Takeshi , Fukumizu Takefumi , Aoyama Takashi , Okuda Akihiko , Makide Yoshihiro
Published: July 2006

In the presence of bromine as a scavenger, the yields of the radiolysis products in eleven kinds of C1–C3 chlorofluorocarbons were investigated by means of gas chromatography. The G-values for the rupture of bonds in radiolysis were found to correlate with the halogen composition and the structure of their molecules. The G-values for the C–Cl (or C–F) bond rupture generally appear to increase with the number of chlorine (or fluorine) atoms in the chlorofluorocarbons; there was a marked difference between the G-values for the C–Cl rupture in each pair of structural isomers of chlorofluoroethanes. A striking selectivity in bond rupture was observed between the two C–C bonds in the chlorofluoropropanes.
Donor–Acceptor Interactions in the Ground State of the Systems Forming Heteroexcimers in the Excited State
Authors: Okada Tadashi , Mataga Noboru
Published: July 2006

Several systems which form heteroexcimers in the excited state were forced to aggregate in low temperature rigid matrices, and their absorption, fluorescence excitation and emission as well as fluorescence rise and decay curves were determined. The results indicate the existence of several kinds of donor-acceptor pairs emitting heteroexcimer fluorescence at different wavelengths. Temperature dependence of absorption spectra of those systems in liquid solutions were examined, and collisional enhancement of the absorption intensity was observed.
The Viscosity of Tetraphenylphosphonium and -arsonium Halides in Water
Authors: Takaizumi Katsuko , Wakabayashi Toshiki
Published: July 2006

A viscometer, the inside of which was thoroughly coated by silicon grease, was prepared because it is difficult to measure precisely the viscosities of aqueous solutions of tetraphenylonium salts by means of a usual flow-type viscometer because of the characteristic peculiar to these solutions, that they make the glass wall water-repellent and water droplets tend to adhere to it. By comparing the relative viscosities on sucrose and LaCl3 in water obtained by the coated viscometer with those found in the literature, it was confirmed that the viscometer operates adequately. The viscosities of Ph4PCl, Ph4PBr, Ph4PNO3, Ph4AsCl, and Ph4AsBr in water have been measured at 15, 25, and 35 °C. The ionic B-coefficients determined at 25 °C are 1.09 mol−1 for both cations, while the ionic activation energies for viscous flow are +4.98 and +5.02 kJ/mol for Ph4P+ and Ph4As+ respectively.
Magnetic Circular Dichroism Studies on o-, m-, and p-Nitroanilines and o-, m-, and p-Aminobenzoic Acids
Authors: Kaito Akira , Tajiri Akio , Hatano Masahiro
Published: July 2006

The MCD and UV spectra of o-, m-, and p-nitroanilines and o-, m-, and p-aminobenzoic acids were measured. Some ambiguous absorption bands, which strongly overlap each other, can be separated in the MCD spectra. The Faraday B terms were calculated using wave functions obtained from the Pariser-Parr-Pople (PPP) method; the values are in good agreement with the experimental values derived from the MCD spectra. The spectral assignments are discussed not only by comparing the excited states of nitroanilines and aminobenzoic acids with those of benzene itself, but also by taking account of the electron migration between the benzene ring and the substituent groups. On the other hand, it turns out from the measurements of the MCD spectra that the zwitterion, C6H4(NH3+)CO2−, exists in aqueous solutions of o- and m-aminobenzoic acids.
Reactions of Recoil 80Br Activated by the (n, γ) Process with Some Gaseous Cyclanes (C4–C6)
Authors: Saeki Masakatsu , Tachikawa Enzo
Published: July 2006

The reactions of 80Br from the (n,γ) process with cyclanes (C4–C6) have been systematically investigated. The primary products formed by the 80Br-for-H reaction were excited and underwent at least two modes of unimolecular decomposition. One was the elimination of the H80Br molecule, and the other was the cleavage of the ring, giving the corresponding bromo-olefin and olefin. The former process was important particularly in the lower-pressure end. Thus, the reaction was easily suppressed by increasing the pressure. However, the latter process showed a different feature; that is, the yields of the decomposition products stayed at an almost constant level over the whole pressure range studied. This indicates that a highly excited product decomposes preferentially through a ring-cleavage reaction. When the total organic yield from each reaction system was plotted against the carbon number of the reactant molecules, a linear correlation was obtained. After some possible consideration, it was concluded that the life of the intermediate complex might play a more important role in the reaction of 80Br with cyclanes than the other factors. Some considerations about the radiolysis of the reactant molecule are also mentioned.
Photocyclization of Diphenylmaleonitrile in the Crystalline State
Authors: Ichimura Kunihiro , Watanabe Shoji
Published: July 2006

Diphenylmaleonitrile shows polymorphism. The crystals are photochromic and afford 9,10-dicyanophenanthrene and 9,10-dihydro-9,10-dicyanophenanthrene after prolonged irradiation. The rates of photodecomposition and properties such as photochromism, absorption and fluorescence spectra depend upon the crystal form. Photochromism results from the formation of the 4a,4b-dihydrophenanthrene which is successively converted into the photoproducts.
Ring-enlargement of Methoxynaphthalenes with Dichlorocarbene to Benzotropone Derivatives
Authors: Sato Masaru , Tsunetsugu Josuke , Ebine Seiji
Published: July 2006

The dichlorocarbene addition to various di- and trimethoxynaphthalenes has been investigated systematically. It has been found that the carbene addition is oriented by the 1-methoxyl group to the 3,4-double bond and by the 2-methoxyl group to the 1,2-double bond of naphthalene nucleus, and that the spontaneous cyclopropane ring-opening of the intermediate carbene-adducts leads to the preferencial formation of 2,3-benzotropone over 4,5-benzotropone derivatives. The steric effects by methoxyl group seem not to be significant in either the carbene-addition or ring-opening reaction.
Kinetics on the Carbonylation of Cyclohexene in a Methanol Solution Catalyzed by Palladium(II) Chloride–Triphenylphosphine
Authors: Yoshida Hajime , Sugita Nobuyuki , Kudo Kiyoshi , Takezaki Yoshimasa
Published: July 2006

Methyl cyclohexanecarboxylate was obtained in high yields by the carbonylation of cyclohexene in a methanol solution using palladium(II) chloride–triphenylphosphine as the catalyst. The effects of variables, such as initial concentration of palladium(II) chloride, pressure of carbon monoxide, and temperature, upon the rate of carbonylation were examined kinetically. A probable reaction mechanism is proposed.
New Cross Aldol Reactions. Titanium Tetrachloride-promoted Reactions of Silyl Enol Ethers with Carbonyl Compounds Containing A Functional Group
Authors: Banno Kazuo
Published: July 2006

It was found that, in the presence of titanium tetrachloride, silyl enol ethers selectively react with aldehyde or ketone function of various carbonyl compounds containing another functional group giving the corresponding cross aldols in good yields. The present cross aldol reaction was successfully applied to the synthesis of arturmerone, one of the volatile principles of turmeric oil.
Cation, Solvent, and Substituent Effects on the Optical Spectra of Alkali Metal Salts of Arylthiolate Anions
Authors: Miyashita Tokuji , Aoki Takao , Matsuda Minoru
Published: July 2006

The optical spectra of the alkali metal salts of arylthiolate anions have been studied in the two aprotic solvents, tetrahydrofuran (THF) and dimethylformamide (DMF). In the former solvent the position of the absorption maxima depends on the size of the counter cations, even at low temperatures (−72 to −76 °C); nearly linear relationships were observed between the inverse of the alkali metal radius (rc) and the wave number of the transition (\ ildeνmax) for both room and low temperatures. The intercepts for the extrapolation of both lines for 1/rc→0 agree with the \ ildeνmax of the ion pairs observed in DMF at room temperature, and the absorption maxima for this solvent are independent of the size of the counter cations. Thus, the existence of contact ion pairs in THF over the temperature range investigated and that of the solvent-separated ion pairs in DMF at room temperature were revealed. In the latter solvent, however, a hypsochromic shift was observed on lowering the temperature. The substituent effect of arylthiolate anions and the solvent effect of dimethoxyethane and dioxane on the absorption maxima are also discussed. From an inspection of optical spectral data it has been suggested that negative charge of arylthiolate anions is localized mainly on the sulfur atom.
Studies of the Surface of Titanium Dioxide. III. The Electrical Conduction and the Hydrogen Uptake
Authors: Iwaki Toru , Miura Masaji
Published: July 2006

The changes in the electrical conductance and the hydrogen uptake of titanium dioxide were examined with the introduction of hydrogen at 250–500 °C. The former was found to approach the equilibrium rapidly, compared with the latter above 350 °C.
Rapid Qualitative and Quantitative Microanalysis of Organic Substances by Means of a Glass-ring Oven Technique. III. Determination of a Trace Amount of Brucine in Strychnine Nitrate
Authors: Chiba Atsushi
Published: July 2006

A rapid and highly selective method for the microdetermination of brucine in strychnine nitrate by the ring oven technique is presented. Nitric acid was used as a developing solution and color reagent. The detection limit was 0.2 μg, and the time needed for the determination about 5 min.
Morpholinobenzoquinones: Synthesis and Reactions
Authors: Omote Yoshimori , Komatsu Toshihiko
Published: July 2006

Two 4-morpholino-1,2-benzoquinones (5-t-butyl- and 5-methyl-) have been prepared by the oxidation of the corresponding catechols with silver oxide. The quinones were then condensed with o-phenylenediamine to give phenazines.
Pyrolysis of S-[2-(Phenylthio-, Phenylsulfinyl-, and Phenylsulfonyl)ethyl]-N-p-tosylsulfilimine
Authors: Furukawa Naomichi , Hatanaka Toshifumi , Harada Katsumasa , Oae Shigeru
Published: July 2006

The β-substituent effect on the rate of Ei reaction was investigated by using S-(2-phenylthio-, phenylsulfinyl-, and phenylsulfonyl)ethyl]-N-p-tosylsulfilimines. The reactivity lies in the order of β-substituents: Ph-SO2>PhSO>PhS>Ph. From this and the kinetic isotope effect, the rate determining step is the intramolecular β-hydrogen abstraction by the N-p-tosyl group.
Tri(hetero)substituted Carbonium Ions. XII. A Novel Ring Expansion of 1,3-Dithiolanyiium Salts into 1,3-Dithia-4-cyclohexene (1,3-Dithiine) System
Authors: Hiratani Kazuhisa , Nakai Takeshi , Okawara Makoto
Published: July 2006

Pyrolysis of 2-dialkylamino-4-bromomethyl-4-methyl-1,3-dithiolanylium bromides (2) readily prepared by bromination of the S-(2-methylallyl) dithiocarbamates afforded the six-membered 2-alkylimino-5-methyl-1,3-dithiines (4) in good yields. A reasonable mechanism for the novel ring expansion is presented.
Substituent Effects for the Benzene Ring on Solvolysis of 3,4-Benzotricyclo[4.3.1.01,6]dec-3-en-2-yl p-Nitrobenzoate
Authors: Ohkata Katsuo
Published: July 2006

Preparations of anti-4′-substituted 3,4-benzotricyclo[4. 3. 1. 01,6]dec-3-en-2-yl p-nitrobenzoates (1a–d) are described. The solvolysis of these esters was examined in 80% aqueous acetone. The rates were relatively high but the sensitivity to substituents on the benzene ring was low in comparison with other secondary systems. It is considered that σ-participation rather than π-conjugation might contribute to the rate accelerative effect. In the presence of a base, 1a–d gave anti-alcohol (12a–d) (13 to 17%), syn-alcohol (13a–d) (31 to 78%), and tert-alcohol (14a–d) (5 to 54%). The product distributions are explained in terms of a nonclassical homonaphthalenium cation (24).
Heat of Ion Exchange Reaction as Determined by Means of Flow Micro-Calorimetry. I. Cation Exchange in Aqueous System
Authors: Morimoto Tetsuo , Naono Hiromitu , N\={o}so Kuniji , Shigetomi Yasumasa
Published: July 2006

The applicability of flow micro-calorimetry to the measurement of ion exchange heat was investigated by use of H-form resin of Dowex 50W×4 having a low degree of cross-linking. It was found that: accurate measurement of ion exchange heat can be performed by means of flow micro-calorimetry; the data obtained include additional heat effects such as heats of invasion and dilution; the effects can be exactly analyzed experimentally and eliminated for calibrating the data of pure ion exchange heat. The ion exchange heat thus obtained for the H-form resin and alkali metal ions was found to agree with the results obtained by means of heat of immersion measurements.
Photochemistry of Cyclobutanes. I. Photolysis of Naphthalene peri-Fused Cyclobutanes in Rigid Media. Photocleavage from an Upper Triplet State
Authors: Honda Koichi , Yabe Akira , Tanaka Hideaki
Published: July 2006

The photocleavage reaction of naphthalene perp-fused cyclobutanes (I–IV) in rigid media is found to proceed from one (or several) of the upper triplet states. Nearly planar cyclobutanes (I–III), which were photocleaved in fluid solutions to yield acenaphthylene and 1,2-ethylenedicarboxylic acid derivatives, afford 1,8-naphthalenediacrylic acid derivatives in addition to the above products by irradiation in rigid media. Twisted cyclobutane (IV), which is considerably stable to irradiation in fluid solutions, was also photocleaved in rigid media to give dimethyl 1,8-naphthalenediacrylate. An NMR study shows that the formation of these diacrylic acid derivatives from I–IV in rigid media is considerably stereospecific. The yield ratio of diacrylic acid derivatives to acenaphthylene formed in the photolysis of I–III is independent of the viscosity of the solvents, i.e., of the matrix rigidity, but depends on other properties of the rigid solvents. A concerted mechanism is proposed for the photocleavage reaction of I–IV in rigid media in order to explain the photochemistry different from that in fluid solutions.
Hydrogen Bonding Systems Containing Hydrogen Fluoride. III. Infrared Frequency Shifts and CNDO/2 Calculations on HF-Carbonyl Compound Complexes
Authors: Tsuda Mitsunori , Touhara Hidekazu , Nakanishi Koichiro , Watanabe Nobuatsu
Published: July 2006

CNDO/2 calculations were carried out for the hydrogen bonded complexes between hydrogen fluoride (HF) and a series of organic compounds having a carbonyl group as a proton acceptor. Infrared spectral measurements were also made to obtain the frequency shifts of H–F stretching vibration, ΔνHF, for the same complexes in dilute carbon tetrachloride solution. Optimum geometry was obtained on the assumption of planar complex. For all the carbonyl compounds used, the interatomic angles, ∠C–O···H, were 120°–123° for the most stable conformation. The changes in the distance between H atom and F atom, ΔRHF, were in good correlation with ΔνHF obtained from IR spectra. Calculated hydrogen bond energies were also in good correlation with ΔνHF, though their absolute values were somewhat larger than those derived from experimental observations. This indicates that the CNDO/2 calculations give relatively correct enthalpy values for the hydrogen bond complexes of a given donor with a series of molecules having a common acceptor group. Other correlations of ΔνHF with properties expected to change with the hydrogen bond formation were also confirmed. These include the energies of each bond obtained by the partitioning of the total energy and the force constant of H–F bond. The electron population on the oxygen atom and other atoms participating in the hydrogen bond formation, the charge transfer, ionization potentials and dipole moment enhancements were also calculated and discussed in terms of the measure of hydrogen bond strength.
An INDO-MO Study of the Conformations and Electronic Structures of HCHOH+, CH3CHOH+, (CH3)2COH+, HCO2H2+, CH3CO2H2+, and CH3OH2+
Authors: Ohkubo Katsutoshi , Yoshida Toshiaki , Tomiyoshi Katsumi
Published: July 2006

INDO-SCF calculations were performed on several protonated compounds, HCHOH+ CH3CHOH+, (CH3)2COH+, HCO2H2+, CH3CO2H2+, and CH3OH2+, and also on the corresponding parent molecules in order to investigate their conformations and electronic structures. Geometric optimization resulted in reasonable conformations as compared with the previous ab initio calculations and in sufficient magnitudes of the energy differences between the rotational isomers in comparison with the NMR observations. The change in the electronic structures of the parent molecules due to protonation is also discussed by paying attention to the polarization caused by electron delocalization, hybridization at the proton-bound oxygen atom, the protonation energy, and the ionization potentials.
Solvolysis of 2,3-Cyclopenteno-4H-homochromen-4-ol Acetate: Comparison with the Corresponding Carbocyclic System
Authors: Yamaoka Hiroshi , Ohkata Katsuo , Hanafusa Terukiyo
Published: July 2006

A novel secondary cyclopropylphenylmethyl acetate was prepared from a chromone skeleton via homochromone derivatives in order to study solvolytic behavior. Reduction of the cyclopropyl ketone (homochromone) with lithium aluminum hydride in ether to the corresponding secondary alcohol, was found to be highly stereospecific giving only one of the geometrical isomers. The alcohol was converted into its acetate and subjected to solvolysis in 80% acetone–water. The acetate was hydrolyzed at the rate of 3×10−5 s−1 (25 °C) undergoing alkyloxygen fission. This rate constant was as high as the most reactive secondary esters in solvolyses ever reported, and about 20 times as high as the corresponding carbocyclic ester by estimation of the same leaving group. Product studies were undertaken in the presence of sodium hydrogencarbonate, and seven-membered hemiacetal was obtained in good yield. The structural characteristics of the homochromenol ester in the solvolysis are discussed and benzohomopyrylium ion, an extremely delocalized homoaromatic species, is proposed as an intermediate carbocation.
A Light Scattering Study of the Hydrolytic Behavior of Zirconium(IV) and Niobium(V) in a Hydrochloric Acid Solution
Authors: Shiokawa Yoshinobu , Sato Akiko , Suzuki Shin
Published: July 2006

The hydrolytic behavior of zirconium(IV) and niobium(V) in a hydrochloric acid solution was studied using light scattering measurements. It is found that the species of zirconium(IV) have a degree of polymerization of 3 and a charge per monomer unit of 1.5 in a 1.5 M hydrochloric acid solution with [Cl−]=1.7 M. Also, it was found that for a chloride ion concentration of 11 M, the species of niobium(V) are monomeric in 8–11 M hydrochloric acid and colloidal below 8 M. The effect of standing time of the hydrochloric acid solution of niobium(V) was also investigated.
Binuclear Metal Complexes. XV. Copper(II) and Nickel(II) Complexes of Binucleating Ligands Derived From 3-Formyl-salicylic Acid and Diamines
Authors: Tanaka Mitsunori , Kitaoka Michiyo , Okawa Hisashi , Kida Sigeo
Published: July 2006

Copper(II) and nickel(II) complexes of the 3-formylsalicylic acid-diamine Schiff bases, H4fsaen, H4fsapn, H4fsatn, H4fsaph, and H4fsach, where en, pn, tn, ph, and ch denote ethylenediamine, propylenediamine, trimethylenediamine, o-phenylenediamine, and 1,2-cyclohexanediamine respectively, have been obtained and characterized. Binuclear copper(II) complexes, Cu2(fsaen)·2H2O, Cu2(fsapn)·2H2O, Cu2(fsatn)·2H2O, Cu2(fsaph)·H2O, and Cu2(fsach)·2H2O, show a strong antiferromagnetic spin-exchange interaction between metal ions, −2J values being more than 555 cm−1. It was revealed that Ni2(fsaen)·3H2O, Ni2(fsapn)·3H2O, Ni2(fsaph)·5H2O, and Ni2(fsach)·3H2O are novel binuclear complexes composed of one paramagnetic and one diamagnetic nickel(II) ions. On the other hand, Ni2(fsatn)·5H2O is a binuclear complex of paramagnetic nickel(II) ions. Its magnetism obeys the Curie-Weiss law in the range from liquid nitrogen temperature to room temperature with the Weiss constant of −40 K.
Successive Spectrophotometric Determination of Palladium and Platinum
Authors: Mizuno Kingo , Miyatani Giroku
Published: July 2006

The absorbance of the water soluble red complex of palladium(II) and 4-(2-pyridylazo)resorcinol (PAR) was measured at 513 nm. Coned hydrochloric acid and tin(II) chloride were added to an aliquot of the red solution, and both the palladium complex and the excess of PAR were decolorized by the reduction of the azo radical of PAR. The absorbance of the platinum complex with tin(II) chloride was measured at 403 nm.
Kinetics of Ligand Substitution Reaction of Some Aminopolyacetatonickel(II) Complexes with Reference to Activation Parameters
Authors: Funahashi Shigenobu , Tanaka Motoharu
Published: July 2006

The substitution reactions of some Ni(II)–L complexes (L: ethylenediamine-N,N′-diacetate, edda2−·, nitrilo-triacetate, nta3−·, iminodiacetate, ida2−) with 4-(2-pyridylazo)resorcinol (H2par) have been studied spectrophoto-metrically at I=0.10. Rate constant k (mol dm−3, s) at 25°C, activation enthalpy ΔH\eweq/kJ mol−1 and activation entropy ΔS\eweq/J K−1 mol−1 are respectively: 1.7×103, 58.5 and 12.5 for k[Ni2+][Hpar−]; 4.0×102, 51.8 and −22 for k[Ni(nta)−][Hpar−]; 1.0×103, 41.8 and −46 for k[(par)Ni(edda)][Hpar−]; 2.7×10−4, 109 and 30 for k[(par)Ni(edda)2−]; 5.1×103, 88 and 17 for k[(par)Ni(Hedda)−]; 1.7×103, 122 and 226 for k[Ni(ida)][Hpar−]. In terms of activation parameters some discussions are made on the effect of coordinated ligands on the lability of leaving ligands and pre-equilibrium involving partial dissociation of leaving ligands.
Photolysis of Organic Azides. II. The Photolysis of 2,2′-Diazido-biphenyl in Rigid Matrices at Low Temperatures
Authors: Yabe Akira , Honda Koichi
Published: July 2006

The direct, triplet-sensitized, and low-temperature photolyses of 2,2′-diazidobiphenyl have been studied. The direct irradiation afforded 4-azidocarbazole, and the triplet sensitization resulted in the predominant formation of the azo dimer, accompanied by a low yield of benzo[c]cinnoline. The photolysis in a rigid matrix at 77 K afforded benzo[c]cinnoline quantitatively. The mechanism for its preferential formation in low-temperature matrix photolysis is discussed, and we propose a biphotonic process involving a dinitrene via a mononitrene.
Reaction of Alkyl Halides with Mercury(II) Salts in Tetrahydrofuran. A Facile Preparation of 4-Alkoxybutyl Acetates and Chlorides
Authors: Watanabe Nanao , Uemura Sakae , Okano Masaya
Published: July 2006

The reaction of primary and secondary alkyl iodides and bromides with Hg(OAc)2 and HgCl2 in tetrahydrofuran (THF) affords the THF-incorporated compounds (1), RO(CH2)4X [X=OAc and Cl, respectively], in good yields. When HgBr2 and aqueous or alcoholic Hg(ClO4)2 were used as mercury(II) salts, the yields of 1(X=Br, OH, and OR′) were low. Similar treatment with HgI2 gave scarcely any 1. A reaction scheme which involves O-alkyltetrahydrofuranium ion as the intermediate is proposed for the formation of 1.
CIDNP Investigation of Aminyl Radicals Formed by Thermolysis of Triazenes
Authors: Albert Klaus , Dangel Karl-Michael , Rieker Anton , Iwamura Hiizu , Imahashi Yuzo
Published: July 2006

Thermolysis of asymmetric triazenes Ar–N=N–NH–R 1 produces anilines Ar–NH2  2, hydrocarbons R–H 3, and N-alkylated anilines Ar–NH–R 4 as the main reaction products. 1H- and 13C-CIDNP experiments show polarization of nuclei in Ar–NH2, Ar–NH–R, R–H and some additional products (especially ring alkylated anilines). These observations are in agreement with the formation of an intermediate radical pair [Ar–NH··R] which must have been formed via homolysis of the tautomeric form ArNH–N=N–R 1′. Temperature-dependent 13C-NMR spectra show a rapid equilibrium between 1 and 1′ at room temperature and above, the tautomeric form 1 being predominant. From the CIDNP spectra the signs of the 1H and 13C hyperfine couplings of aminyl radicals Ar–NH and alkyl radicals R. have been determined.
Photolyses of Ethyl Azidoformate in Cyclic Ethers
Authors: Torimoto Noboru , Shingaki Tadao , Nagai Toshikazu
Published: July 2006

Ethoxycarbonyl nitrene, generated by the photolysis of ethyl azidoformate (I), were inserted preferentially into the α C–H bonds of cyclic ethers. The α C–H bonds of cyclic ethers were much more reactive than the corresponding C–H bonds of hydrocarbons for the insertion of the nitrene. In addition, the reactions in cyclic ethers with an alkyl group at the α-position gave unsaturated alkoxyurethanes via a cleavage of the ring C–O bond. It was found that the nitrene insertion into the α C–H bonds of cis- and trans-2,5-dimethyltetrahydrofurans proceeded non-stereospecifically, while the insertion into the C–H bonds of hydrocarbons proceeded stereospecifically. The formation of the alkoxyurethanes can be explained by a mechanism in which an O–N ylide is included as an intermediate of the nitrene reaction; the non-stereospecific insertion of the nitrene give support to this mechanism.
The Reaction of Arylthallium(III) Compounds with Metal Nitrite. Synthesis of Nitroarenes.
Authors: Uemura Sakae , Toshimitsu Akio , Okano Masaya
Published: July 2006

Arylthallium(III) compounds react smoothly with various metal nitrites such as NaNO2, KNO2, and AgNO2in trifluoroacetic acid to give nitroarenes in good yields. It has been clarified that the reaction proceeds through substitution of thallium moiety by nitroso group at the (ipso) position where thallium was attached previously to aromatic ring to give nitrosoarenes, followed by their oxidation to nitroarenes.
Reaction of Carboxylic Acids with Dioxygen Complexes: A Mechanistic Aspect of the Reaction
Authors: Muto Shigeaki , Kamiya Yoshio
Published: July 2006

The reaction of carboxylic acids with dioxygen complexes MO2(PPh3)2(M=Pt, Pd) at low temperature gives rise to the selective formation of H2O2 and the corresponding dicarboxylato complexes characterized by their physical properties. It is suggested that the reaction can be influenced by either the capability of reactant for coordination to metal center or the stability of resulting metal complex. An equimolar addition of CH2ClCOOH to the dioxygen complexes in the presence of triphenylmethyl bromide at ca. −70 °C gives triphenylmethyl hydroperoxide and the corresponding monocarboxylato complexes in good yields, indicating that the reaction of organic acids with MO2(PPh3)2 proceeds by stepwise mechanism.
Studies in Heterocyclics. VI. Synthesis of Thiazolo-Benzo-Triazepines
Authors: Mahajan M P , Sondhi S M , Ralhan N K
Published: July 2006

2-Imino-3-(o-aminoaryl)-4-thiazolines (II) gave thiazolo-benzotriazepines(I) on condensation with various aliphatic carboxylic acids. Both N-acyl(III) and N,N′-diacyl derivatives(IV) were isolated, and the monoacyl derivatives (III) were also cyclized to thiazolo-benzo-triazepines.
Photochemistry in the Adsorbed Layer. VII. Steric Hindrance in the Type II Cleavage of Adsorbed Alkyl Eetones
Authors: Anpo Masakazu , Kubokawa Yutaka
Published: July 2006

The type I selectivity in the photolysis of adsorbed alkyl ketones is larger for 3-methyl-2-pentanone than for 2-pentanone. Such behavior can be explained by the concept that the type II cleavage is more hindered for the former owing to a steric hindrance arising from the presence of a solid surface.
A Theoretical Analysis of Rotational Isomerism; CNDO/2 Calculations of i-PrSMe, i-PrSEt, i-Pr–S–n-Pr, and (i-Pr)2S
Authors: Ohsaku Masaru , Bingo Norihisa , Eida Kanzo , Murata Hiromu
Published: July 2006

CNDO/2 calculations of i-PrSMe, i-PrS-Et, i-Pr–S–n-Pr, and (i-Pr)2S gave the stable conformations of these molecules and the optimized angles of φ(CSC) of the first three molecules considered.
Reaction Process between Cobalt Tungstate and Chlorine
Authors: Nishihara Hisao , Matsuzaki Ryoko , Saeki Yuzo
Published: July 2006

The reaction between CoWO4 and chlorine proceeds above about 585 °C to form WO2Cl2 and CoCl2. In the presence of carbon, the reaction proceeds above about 345 °C to form CoCl2 and WO3, the WO3 subsequently reacts with chlorine to form WO2Cl2 and WOCl4.
Gamma-Rays Treatment of Odorous Compound in Water
Authors: Irie Setsuko , Kato Norio , Kinoshita Shosaku
Published: July 2006

γ-Rays treatment of earthy odors in public water supplies due to the metabolites in Lake Biwa was studied. The odorous compound was isolated from the metabolites and was identified to be geosmin by the use of gas chromatographmass spectrometer. The effect of additives and competition reaction with p-nitroso-N,N-dimethylaniline revealed that geosmin is decomposed effectively by hydroxyl radical produced by the radiolysis of water.
Apparatus for Thermal Analytic Microscopy and Its Application to Cholesteryl Nonanoate
Authors: Kunihisa Kazuko Sasaki , Hagiwara Seiichi
Published: July 2006

The phase transitions of cholesteryl nonanoate were studied by means of a newly constructed apparatus for thermal analytic microscopy incorporating a thermoelement. It was possible to determine the heat of mesophase transitions more accurately. The transition values of cholesteryl nonanoate on cooling were obtained with the same accuracy as those on heating. The heat of the smectic-solid transition was obtained by slow cooling, which suppressed the supercooling. The vortices caused by cholesteric spherulites, which are similar to those of cholesteryl octanoate, change to circular arrangements of batonnets in the smectic phase. Color changes were observed at the cholesteric-smectic transition in extremely thick specimens. The relations between texture, color, and heat at the cholesteric-smectic transition of cholesteryl nonanoate are discussed.
An Application of H0,max for Estimating the Catalytic Action of Solid Acids and Bases in the Isopropylation of m-Cresol
Authors: Yamanaka Tohr
Published: July 2006

A method of estimating the acid-base property of the active sites in terms of the correlation between the catalytic activities of various solids and their H0,max values is presented. The H0,max denotes an H0 value of the strongest acidic sites and/or conjugate acids of the strongest basic sites. The types of catalytic actions over oxides, hydroxides, a sulfide, sulfates, phosphates, tungstates, and multi-component solid acids in the liquid-phase isopropylation of m-cresol without a solvent were classified into three groups: via a carbonium ion, via a carbanion, and concerted actions. The selectivity for the ortho-isopropylation over every catalyst increased with the increase of H0,max, and this effect of H0,max was explained by the orientation of the adsorbed m-cresol on the catalyst surface.
Catalytic Properties of Metal Sulfates Supported on γ-Al2O3 in the Liquid-Phase Isopropylation of m-Cresol with Propylene
Authors: Yamanaka Tohr
Published: July 2006

γ-Al2O3 was impregnated with various metal sulfates, calcined, and used as catalysts in the liquid-phase isopropylation of m-cresol at 250–300 °C, with the propylene pressure in the range from 15 to 79 kg/cm2. The catalytic activities of the sulfates were in the order: Al2(SO4)3>ZnSO4≈NiSO4>FeSO4>CuSO4>Li2SO4≈ none≈CaSO4>Na2SO4. The order of the selectivity Φ for ortho-isopropylation over para-isopropylation was opposite to that of the catalytic activity. FeSO4/Al2O3 catalysts resulted in the best Φ value and fairly high activity, which were independent of the calcination temperature over the range of 300–500 °C. The formation of Brønsted acidic sites with 1≤H0≤3 as catalytically-active sites was estimated for the FeSO4/Al2O3 and ZnSO4/Al2O3 catalysts.
The Dual Fluorescence Nature of Some N-Monosubstituted Salicylamides
Authors: Kondo Michio
Published: July 2006

Dual fluorescence from N-methylsalicylamide (1) in alcoholic solutions was observed under excitation by 280 nm light, and was ascribed to two different molecular species: one with and the other without intramolecular proton transfer in the lowest excited singlet state. Some related compounds having two identical chromophores showed similar dual emission spectra with weak emission bands at shorter wavelengths. This fact was explained as being due to the intramolecular energy transfer between the two chromophores in the excited state. From the temperature dependence of the intensity ratio of the two emission bands for these compounds, the difference between the activation energies for the two emissive states was estimated.
A Study of trans Influence in Methylmercury(II) Compounds by Means of Vibrational Analysis
Authors: Iwasaki Noriko
Published: July 2006

Force constants K(Hg–C) were evaluated for a series of methylmercury compounds: CH3HgX (X=CH3, F, Cl, Br, I, CN, SCN, As(CH3)3, SCH3, SHgCH3, and S(HgCH3)2). It was found that K(Hg–C) increases in the following order of X: S(HgCH3)2(1.86)<I(2.27)<SCH3(2.33)=CH3(2.330)<As(CH3)3(2.37)≤Br(2.377)≤SHgCH3(2.38)≤Cl(2.382)<SCN(2.39)<F(2.55)<CN(2.61 md/Å). This order coincides, except for the cases of CN and As(CH3)3, with the order of increase in the first ionization potential of X for X=I, SCH3, CH3, Br, Cl, and F. Since this effect of X upon K(Hg–C) is regarded as a vibrational trans influence, this order was compared with that of the coupling constants in NMR, J(199Hg–13C) and J(199Hg–1H), and with the order of the bond-dissociation energy of CH3HgX into ·CH3 and ·HgX.
A Kinetic Study of the Chromium(II) Reduction of Several (Amino acid)pentaamminecobalt(III) Complexes
Authors: Ogino Hiroshi , Tsukahara Keiichi , Tanaka Nobuyuki
Published: July 2006

A kinetic study of the chromium(II) reduction of (O-bonded amino acid)pentaamminecobalt(III) complexes has been carried out in acid solutions. The second-order rate constants in M−1 s−1 (1 M=1 mol dm−3) at 25 °C and I=1.0 M (NaClO4) for α-alanine, phenylalanine, α-aminoisobutyric acid, β-alanine, β-aminobutyric acid, γ-aminobutyric acid, and ε-aminohexanoic acid complexes are 1.8×10−2, 1.5×10−2, 2.4×10−3, 7.5×10−2, 5.0×10−2, 1.22×10−1, and 1.49×10−1 respectively. The values of ΔH\eweq lie in the range of 6.4–7.7 kcal mol−1 (1 cal=4.184 J), and those of ΔS\eweq, in the range of −42–−37 cal K−1 mol−1, except for the α-aminoisobutyric acid complex, the ΔH\eweq and ΔS\eweq values of which are 11.4 kcal mol−1 and −32 cal K−1 mol−1 respectively. The role of the amino acid ligands in the inner-sphere electron-transfer reactions is discussed.
Oxidation of Acetaldehyde Catalyzed by Cobalt(II) Tetraphenylporphyrin
Authors: Tezuka Meguru , Sekiguchi Osamu , Ohkatsu Yasukazu , Osa Tetuo
Published: July 2006

Cobalt(II) tetraphenylporphyrins catalyzed the autoxidation of acetaldehyde giving peracetic acid quantitatively. The p-substituents of phenyl groups of tetraphenylporphyrin influenced the catalytic activity, cobalt(II) tetra(p-methylphenyl)porphyrin being remarkably active. The effect of the base added into the reaction system was such that an appropriate quantity of the base gave rise to a maximum rate of oxidation. The rate equation was determined experimentally. From the results of kinetics and ESR study, it was concluded that an oxygen molecule activated through the electron transfer from a cobalt(II) ion abstracted the hydrogen of acetaldehyde to initiate the autoxidation.
The Association Constants of Hexaamminechromium(III) and Tris(ethylenediamine)chromium(III) Ions with Several Univalent Anions in Aqueous Solutions
Authors: Takahashi Tatsuo , Koiso Takefumi
Published: July 2006

The thermodynamic ion-association constants of hexaamminechromium(III) and tris(ethylenediamine)chromium(III) with several univalent anions were determined in aqueous solutions at 25.0 °C. The logKcon values obtained by the conductometric method are 1.37 for [Cr(NH3)6]3+–Cl−, 1.58 for [Cr(en)3]3+-Cl−, 1.57 for [Cr(NH3)6]3+–Br−, 1.50 for [Cr(en)3]3+–Br−, 1.53 for [Cr(NH3)6]3+–NO3−, and 1.49 for [Cr(en)3]3+–NO3−. The log KSP values obtained by the spectrophotometric method are 1.65 for [Cr(en)3]3+–Cl−, 1.46 for [Cr(en)3]3+–Br−, and 0.90 for [Cr(en)3]3+–ClO4−; the value for [Cr(en)3]3+–ClO4− could be indirectly calculated from the apparent ion-association constant of [Cr(en)3]3+–Br− determined in the solutions containing both bromide and perchlorate ions. Though the detailed comparison of the ion-association constants obtained in this study was limited, it could be concluded that the Kcon values were in relatively good agreement with the Ksp values obtained on the given ion-pairs and that the ion-association constants of chromium(III) complex cations with several univalent anions are slightly less than those of the corresponding cobalt(III) complex cations with their anions.
The Photochemical Reaction of 1,2-Naphthoquinones with Aldehydes. II. The Photo-addition Reactions of Aliphatic Aldehydes to 1,2-Naphthoquinones
Authors: Takuwa Akio
Published: July 2006

3-Acyl-1,2-naphthalenediols and 1,2-naphthalenediol monoacyl esters were obtained from the photochemical reactions of 1,2-naphthoquinones with aliphatic aldehydes. 3-Halogeno-1,2-naphthoquinones gave the corresponding 1,2-naphthalenediol monoacyl esters, 3-acyl-1,2-naphthalenediols, which are the same products as those from the photochemical reactions of 1,2-naphthoquinone with those aldehydes and 3-halogeno-4-acyl-1,2-naphtoquinone when they were irradiated in aldehydes. 3-Methyl-1,2-naphthoquinone, however, gave the corresponding 1,2-naphthalenediol monoacetate and 3-methyl-4-acetyl- 1,2-naphthoquinone when it was irradiated in acetaldehyde. These photochemical reactions were applicable for syntheses of 3-acyl-1,2-naphthalenediols and 1,2-naphthalenediol monoacyl esters.
Doubly Charged Ion Mass Spectra of Monosubstituted Aromatic Compounds
Authors: Sakurai Hiroshi , Tatematsu Akira , Nakata Hisao
Published: July 2006

The 2E doubly charged ion mass spectra of twelve simple monosubstituted aromatic compounds were recorded. The spectral pattern of these compounds can be classified into three types. When the substituent is strongly electron-donating such as the amino or dimethylamino group, a very intense molecular ion peak appears, no fragment ion peak being observed. Phenol, anisole, toluene, and chlorobenzene show both molecular and fragment ion peaks in varying intensities. The parent benzene itself behaves similarly. Only fragment ion peaks were observed for nitrobenzene and aromatic carbonyl compounds such as benzaldehyde, acetophenone, methyl benzoate, or benzoic acid. The major fragmentation reactions are discussed.
Catalytic Dehydration of Ethers on Nickel Oxide–Silica–Alumina
Authors: Imai Hisao
Published: July 2006

The dehydration of diethyl ether was studied on synthetic nickel oxide–silica–alumina catalysts in the temperature range of 340–400 °C and at pressures less than 50 Torr. It was found that ethylene, butenes, water, and small amounts of carbon monoxide and methane were formed on the catalysts of lower nickel content. The rate constant for the formation of butenes showd a maximum on the catalyst of 10 atom% nickel. The mechanism of the formation of the butenes was discussed by studying the catalytic dehydration of various ethers.