bluuebunny/crossref_metadata_2025 huggingface dataset:
The Stereochemistry of Autoxidation of Methylcyclohexanes
Authors: Miyajima Shingo , Simamura Osamu
Published: July 2006

Autoxidation of 1, c-3, c-5- or 1, c-3, t-5-trimethylcyclohexane with oxygen in the presence of azobisisobutyronitrile at 60°C and subsequent reduction with lithium aluminium hydride gave 1, t-3, t-5- and 1, c-3, c-5-trimethyl-r-1-cyclohexanol in the same ratio of 1/0.85. Such an almost random attack of oxygen on both sides of intermediate methylcyclohexyl radicals was also observed in autoxidation of 1,2-dimethyl-, 1,4-dimethyl-, and 1,1,3,5-tetramethylcyclohexanes. Approximate relative reactivities of tertiary hydrogens in various steric environments in methylcyclohexanes towards abstraction were determined. Steric effects on the attack of oxygen and the abstraction of hydrogen are discussed.
Synthesis of Di-N-acetyl-di-N-benzyloxycarbonyl-O-cyclohexylidenestreptidine
Authors: Umezawa Sumio , Takahashi Yoshikazu , Tsuchiya Tsutomu
Published: July 2006

Reaction of streptidine with excess benzyloxycarbonyl chloride, followed by partial alkaline hydrolysis, gave di-N-benzyloxycarbonylstreptidine (1), which, by treatment with 3,4-dihydro-2H-pyran, gave a tetra-O-tetra-hydropyranyl derivative (3). Acetylation of 3 then gave a di-N-acetyl derivative (4), which was, after removal of the tetrahydropyranyl groups, allowed to react with 1,1-dimethoxycyclohexane to furnish di-N-acetyl-di-N-benzyloxycarbonyl-O-cyclohexylidenestreptidine (6). This is the first preparation of a useful intermediate for the synthesis of streptidine glycosides.
The Michael Reactions of Chloro-substituted-9,9′-bifluorenylidenes with Fluorenes and a Comparison with Analogous Halogen Compounds
Authors: Minabe Masahiro , Suzuki Kazuo
Published: July 2006

The Michael reactions of 2-chloro- and 2,7-dichloro-9,9′-bifluorenylidenes with fluorenes were investigated. Structures of these products were confirmed by syntheses through the well-established reactions of 9-lithiofluorenes and 9-bromo-9,9′-bifluorenyls. The formation of some abnormal compounds is explained by intermediary formation of 2,7-dichloro-9,9′-bifluorenylidene from the reaction of 9,9′-bifluorenylidene with 2,7-dichlorofluorene as with the bromo-derivatives. The corresponding fluoro- and iodo-series gave predominantly normal addition products. These differences are explained in terms of the inductive and steric effects of the halogen substituents.
Theoretical Study of Proton Chemical Shifts Induced by the Paramagnetic Anisotropy of Cobaltic Ion
Authors: Nakashima Yoshiaki , Sakaguchi Ushio , Yoneda Hayami
Published: July 2006

A new theoretical relation between proton and cobalt-59 chemical shifts in cobalt(III) compounds has been established on the assumption that the proton shift comes primarily from the anisotropy of the second-order paramagnetism of the central cobalt(III) ion. The additivity observed for cobalt-59 chemical shifts in solution is explained and applied to the problem of proton shifts. The relation between 1H and 59Co chemical shifts, coupled with this additivity, allows one to calculate the chemical shift of a proton under the influence of the paramagnetic anisotropy of a cobalt ion.
Proton Magnetic Resonance Spectra of Metal Ammine Complexes. III. Interpretation of the Chemical Shifts in Cobalt(III) Pentaammines
Authors: Nakashima Yoshiaki
Published: July 2006

The ammine proton chemical shifts of a series of compounds [CoX(NH3]n+ have been explained quantitatively. The shifts are ascribed to the paramagnetic anisotropy of central cobalt(III) ions. The discrepancies between the calculated and the observed shift values, though small, noted for the trans ammine protons of complexes with X=CN− and NO2− may be caused by large inductive effects of these ligands.
Theoretical Considerations of Lower Excited States of trans-Polyenecarbaldehydes. II. Radiative and Nonradiative Properties
Authors: Inuzuka Kozo
Published: July 2006

The spin-orbit coupling energies between the lowest 1(n,π*) and 3(π,π*) states, and between the lowest 1(π,π*) and 3(n,π*) states, for the four polyenecarbaldehydes were calculated using the results calculated within the framework of the conventional P–P–P SGF–MO–CI method. In the present paper, the general properties of the emission spectra of polyenecarbaldehyde are theoretically considered using the calculated results for the spin-orbit coupling energy and their lower electronic structure.
Ion-Molecule Reactions in Carbonyl Sulfide–Hydrocarbon Mixtures
Authors: Matsumoto Akira , Okada Satoshi , Misaki Toshiyuki , Taniguchi Setsuo , Hayakawa Teruo
Published: July 2006

Thermal energy ion-molecule reactions in carbonyl sulfide–hydrocarbon (methane, acetylene and propylene) mixtures were studied using a mass spectrometer equipped with a pulsed ion source. The rate constants for sulfur atom transfer, sulfur ion transfer and sulfur ion addition reactions were measured.
The Mechanism of the Selective Hydrogenation of 1,3-Butadiene on Copper Surfaces
Authors: Nishimura Eiji , Inoue Yasunobu , Yasumori Iwao
Published: July 2006

The hydrogenation of 1,3-butadiene on copper surfaces was studied in detail. A highly selective formation of 1-butene was observed in the range of temperatures from 27 to 76 °C; the initial rate of the formation was well expressed in terms of the partial pressures of hydrogen, ph and butadiene, ph, as v=kph⁄(1+Kpb)2 in the pressure range of 5–100 Torr. The reaction with D2 gave butene-d0 and -d1 as the main products, and the butadiene was partly exchanged with D2 during the hydrogenation. The microwave spectroscopic analysis revealed that the 1-butene produced consisted of CH2=CHCH2CH2D, CH2=CHCHDCH3, and CHD=CHCH2CH3, without even a trace of CH2=CDCH2CH3. Therefore, it was concluded that the reaction proceeds via the isobutenyl surface intermediate and that the dissociative adsorption of hydrogen is rate-determining. The structural analysis of the surface suggested that the stable lattice planes, such as (111), (100)3, and (110), are responsible for the reaction. The origin of the high 1-butene selectivity was discussed on the basis of the surface geometry and the proposed mechanism.
The Mechanism of the Hydrolysis of Condensed Phosphates. II. The Mechanism of the Degradation of Long-chain Polyphosphates
Authors: Watanabe Makoto , Sato Shoji , Saito Hajime
Published: July 2006

The hydrolysis of long-chain polyphosphates (Graham’s salt) was carried out in water and dioxane-water solvents at various pHs in the range from 3.0 to 11.0 and at 30, 50, and 70 °C. The rates of the hydrolytic degradation of the polyphosphates into shorter chains and into trimetaphosphate obeyed the first-order kinetics with respect to the concentration of the polyphosphates. In acidic media, a small solvent effect was perceived on the rates of both the processes. On the other hand, in basic media the effect was very remarkable; that is, the rates of both the processes in the dioxane-water solvent were more rapid than in water. The results show that the rate of the hydrolysis of both the processes in basic media may be very dependent on the step of the nucleophilic attack of a water molecule on the phosphorus atom of phosphates, while in acidic media other factor, for example, the folding of the chains to a helix, may affect the overall rate. The activation energies for the two processes have been found to be 22–26 kcal/mol in the pH range from 3.0 to 7.0.
The Photochemical Reaction of Benzo[c]cinnoline. I. The Photoreduction and Subsequent Reactions in Acidified Alcohols
Authors: Inoue Hiroyasu , Sakurai Tetsuo , Tanaka Fujio
Published: July 2006

The photoinduced reaction of benzo[c]cinnoline (BCC) in strongly acidic aqueous alcohols, in which BCC exists in a monoprotonated form (BCCH+), was investigated. The initial step of the photoreaction was the hydrogen abstraction, which gave rise to 5,6-dihydroBCCH+, irrespective of the excitation wavelengths and the kind of alcohol (methanol, ethanol, or 2-propanol) used as a solvent. The subsequent reaction occurred upon irradiation by a light longer than 400 nm to afford 2,2′-diaminobiphenyl in ethanol, but not in methanol and 2-propanol. The 1-hydroxyethyl radical formed in the initial photoreduction appeared to participate in this reaction, donating its hydrogen atom to the ground-state 5,6-dihydroBCCH+. On the other hand, ultraviolet irradiation caused the subsequent photoreaction of 5,6-dihydroBCCH+, thus giving carbazole accompanied by the liberation of ammonia.
Photochemistry in the Adsorbed Layer. III. Photolysis of Acetone Adsorbed on Porous Vycor Glass
Authors: Anpo Masakazu , Hirohashi S\={o}zi , Kubokawa Yutaka
Published: July 2006

Photolyses of acetone adsorbed showed that the ratio of ethane to methane in the products as well as the kinetic isotope effect for the methane formation is much smaller than that in the gas phase photolysis. The methane formed from acetone-d6 contains a considerable amount of CD3H. Ethane formation is quenched more efficiently by nitric oxide than methane formation. It is proposed that there are two types of methyl radicals, i.e., long- and short-lived ones, the ethane resulting from the long-lived radicals. The results suggest that methane arises from hydrogen abstraction from surface OH groups as well as disproportionation reaction CH3+CH3CO→CH4+CH2CO, in addition to hydrogen abstraction from acetone molecules.
Reactions of Perfluoro-2-methyl-2-pentene and Octafluoroisobutylene with Arylamines
Authors: Ishikawa Nobuo , Nagashima Akira
Published: July 2006

Treatment of perfluoro-2-methyl-2-pentene with four moles of arylamine provided 1-aryl-2,4-bis(arylimino)-3-(1-arylimino-2,2,3,3,3-pentafluoropropyl)azetidine, 3-(N,N′-diarylamidino)-4-arylamino-2-(pentafluoroethyl)-quinoline and 2,4-bis(arylamino)-3-(1-arylimino-2,2,3,3,3-pentafluoropropyl)quinoline, depending on the basicity of the arylamine and on the solvent used. Octafluoroisobutylene also yielded similar azetidine and quinoline derivatives.
Comments on the Energy Calibration in X-Ray Photoelectron Spectroscopy
Authors: Kinoshita Shuichi , Ohta Toshiaki , Kuroda Haruo
Published: July 2006

The change of the contact potential difference between the sample and spectrometer was examined on the adsorbed carbon/Au system by observing the low kinetic energy limit of the X-ray photoelectron spectrum. Discussions are given on the use of the contamination carbon for energy calibration.
The Crystal Structures of Sterigmatocystin and O-Methylsterigmatocystin, Metabolites of the Genus Aspergillus
Authors: Fukuyama Keiichi , Hamada Kensaku , Tsukihara Tomitake , Katsube Yukiteru , Hamasaki Takashi , Hatsuda Yuichi
Published: July 2006

The crystal and molecular structures of sterigmatocystin and O-methylsterigmatocystin have been studied by the X-ray diffraction method. Both compounds crystallized in the space group P21 with Z=2. The cell dimensions are a=16.068, b=4.293, c=11.243 Å, and β=113.23° for sterigmatocystin, and a=8.835, b=16.769, c=5.403 Å, and β=109.21° for O-methylsterigmatocystin.
Phosphinidenes and Related Intermediates. V. Reactions of Phosphinylidenes with cis- and trans-Stilbene Oxides
Authors: Nakayama Shigenobu , Yoshifuji Masaaki , Okazaki Renji , Inamoto Naoki
Published: July 2006

Reactions of phenyl- and cyclohexylphosphinylidenes with trans-stilbene oxide gave trans-stilbene and 4-hydroxybutyl 2-hydroxy-l,2-diphenylethyl phosphonate derivatives. In the case of cyclohexylphosphinylidene, 2-cyclohexyl-3,4-diphenyl-1,2-oxaphosphetane 2-oxide was also formed. Reactions with cis-stilbene oxide gave cis-and trans-stilbenes.
Metal Phosphinylides and Phosphinothioylides. VI. Some Observations in Reactions of Diphenylphosphinic Chloride with Tetrahydrofuran in the Presence of Metal Chlorides
Authors: Goda Koshiro , Inamoto Naoki
Published: July 2006

31P-NMR data showed a formation of a stable 1 : 1 complex between diphenylphosphinic chloride (1) and aluminum chloride. The effect of common chloride ion on the reaction of 1 with tetrahydrofuran in the presence of zinc or cuprous chloride supported a cationic mechanism in the former case, and no free radical but homolytic mechanism in the latter.
An Analytical Study of pre-Inca Pigments, Dyes, and Fibers
Authors: Kashiwagi K Maresuke
Published: July 2006

The total analysis of 800-year-old Peruvian pigments with regard to the inorganic elements was carried out; some typical pigments, like mercury sulfide and iron oxide, are shown. Some characteristic pre-Inca (6–7 th century Tiahaunaco and 13–14 th century Chancay) dyes including cochineal, indigo, and probably logwood were identified from old fabrics by means of absorption spectroscopy and also chromatographic analysis. Two kinds of fiber constituting those fabrics were also investigated, and a few chemical analyses, including that of the amino-acid composition of protein fiber and that of the extent of the degradation of old cellulose fiber, were made.
Formation Constants of Dibenzo-18-crown-6 Complexes with Alkali Metal Ions in DMSO, DMF, and PC at 25°C
Authors: Matsuura Niro , Umemoto Kisaburo , Takeda Yasuyuki , Sasaki Atsuko
Published: July 2006

The formation constants (Kf) for the 1 : 1 complexes of dibenzo-18-crown-6 (DBG) with alkali metal ions in DMSO (dimethyl sulfoxide), DMF (N,N-dimethyl formamide), and PC (propylene carbonate) have been determined conductometrically. The formation constant sequences of the alkali metal ions with DBG in DMSO, DMF, and PC are K+>Rb+>Cs+≅Na+>>Li+, K+>Rb+>Cs+>Na+>Li+, and K+>>Na+>Rb+>Cs+>Li+ respectively. The Kf value series about the same alkali metal ion among these nonaqueous solvents are given in the order of DMSO<DMF<PC. These results show that the selectivity of DBC toward the alkali metal ions is dependent on the ionic diameter and the ring-hole size of DBC, and that the donor number of the organic solvent as a component factor is important in determining the process of the formation of the DBC complexes constant.
Theoretical Calculations of the Raman Intensities by the Vibronic Method. II. The In-plane Vibrations of Ethylene
Authors: Shinoda Hiroyuki
Published: July 2006

The values of the transition moment of Raman scattering have been calculated according to the formula derived from the vibronic method. The calculations have been performed for the in-plane vibrational modes of ethylene determined by three different sets of force constants. The electronic wave functions were calculated by the CNDO/2-CI method. From the relative Raman intensities of three A1g-vibrations of ethylene in the respective cases, it was found that the Raman intensities are sensitive to the vibrational modes. Also, the Raman intensities of ethylene were calculated by the polarizability method in order to compare the results with those obtained from the vibronic method. From the results of these calculations, the conclusions of the previous work have been confirmed.
The Crystal and Molecular Structure of Silver(I) N,N-Diethyldithiocarbamate
Authors: Yamaguchi Hiroko , Kido Azuma , Uechi Tetsuo , Yasukouchi Kazuo
Published: July 2006

The crystal structure of silver (I) N,N-diethyldithiocarbamate was determined by the X-ray diffraction method. The crystals are monoclinic, with the space group P21/c, and with two hexameric molecules in a unit cell with dimensions of a=10.90±0.02, b=24.72±0.01, c=11.51±0.02 Å, and β=125.8±0.1°. The structure was solved by a heavy-atom method and was refined by block-diagonal least-squares methods to a final R-value of 0.029 for 2108 observed reflections. The structure consists of hexameric molecules, [AgS2CN(C2H5)2]6. The hexameric structure was essentially consistent with Hesse’s preliminary result (1960). The terminal silver atom in one molecule is bridged by a sulfur atom to that in the adjacent hexamer, forming a chain structure along the a axis. All the silver atoms are connected to five atoms (either 1Ag and 4S or 2Ag and 3S). The dithiocarbamate ligands are classified into three types: bidentate, intra-, and inter-molecule tetradentate.
Lanthanide Induced Shifts of the PMR Spectra of Polyaza-aromatic Compounds
Authors: Nagawa Yoshinobu , Ono Makoto , Hirota Minoru , Hamada Yoshiki , Takeuchi Isao
Published: July 2006

The LIS’s were determined with the equimolar mixtures of two monoaza-aromatic compounds, and the relative coordinating ability of each ligand was estimated from these LIS’s. The coordinating ability index is defined as the ratio of the complexed species of the monoaza-aromatics to that of pyridine, and is proved to be transferable to the nitrogen atom of similar steric circumstances. Thus, Eu(fod)3 induced shifts of the protons in several unsymmetrical naphthyridines and related heterocycles were estimated by the sum of the induced shifts of the corresponding monofunctional equivalents weighted by the relative abundances of the complexed species which were obtained from the coordinating ability measurements. The method is applicable to other bifunctional compounds of rigid conformation.
Charge-transfer Interaction in Supercooled Melts of Some Derivatives of N-Picrylaniline
Authors: Matsunaga Yoshio
Published: July 2006

Supercooled melts of N-picrylaniline and its derivatives, the molecules of which consist of electron-donating and -accepting moieties, are colored more deeply than the crystals. Many of them exhibit glass transitions.
Ultrasonic Absorption Mechanism in an Aqueous Solution of Isopropyl Alcohol
Authors: Nishikawa Sadakatsu , Mashima Mitsuo , Yasunaga Tatsuya
Published: July 2006

Ultrasonic absorption measurements in an aqueous solution of isopropyl alcohol were made in the frequency range from 5 to 220 MHz and in the concentration range from 3 to 10 M. The excess absorption which is characteristic of a single relaxation process was observed. The mechanism of the excess absorption was interpreted in terms of a reaction expressed by AB\ightleftharpoonsA+B, where A and B are monomeric molecules of alcohol and water respectively. The rate constants for forward and backward reactions were determined from the concentration dependences of the relaxation frequencies. The results obtained were compared with those of aqueous solutions of other alcohols which had already been published.
The Crystal Structure of Bis[1-(2-thiazolylazo)-2-naphtholato]iron(II)–Chloroform(2/3)
Authors: Kurahashi Masayasu , Kawase Akira
Published: July 2006

The crystals of bis[1-(2-thiazolylazo)-2-naphtholato]iron(II)-chloroform (2/3) are triclinic, with unit-cell dimensions of: a=12.509(7), b=11.911(6), c=10.460(4) Å, α=86.97(3), β=97.24(4), and γ=103.48(7)°, Z=2 for [FeII(C13H8N3OS)2]·1.5CHCl3, space group P\bar1. The complex is diamagnetic, and the iron atom is surrounded octahedrally by two terdentate ligands in the mer configuration.
Aromatic Nucleophilic Substitution. VI. 1H Nuclear Magnetic Resonance Evidence for the Rearrangement of 1,3-to 1,1-Anionic σ Complex in the Reactions of 1-Dialkylamino-2,4-dinitronaphthalenes with Potassium Alkoxides
Authors: Sekiguchi Shizen , Fujisawa Shigeru , Ando Yumiko
Published: July 2006

By use of NMR spectroscopy the rearrangement of 1,3- to 1,1-anionic σ complex (Meisenheimer complex) in the reactions of 1-dialkylamino-2,4-dinitronaphthalenes (dimethylamino-, diethylamino-, and N-methyl-N-butylamino, piperidyl) with potassium alkoxides in DMSO has been studied. The alkoxides used are potassium methoxide, ethoxide, isopropoxide, and t-butoxide. In the reactions of 1-dialkylamino-2,4-dinitronaphthalenes with the alkoxides the rearrangement could be spectrometrically analyzed. However, in the reaction of 1-dimethylamino-2,4-dinitro naphthalene with potassium t-butoxide the rearrangement was too fast to be clearly analyzed.
A New Synthesis of the Pungent Principles of Ginger —Zingerone, Gingerol and Shogaol—
Authors: Banno Kazuo , Mukaiyama Teruaki
Published: July 2006

The pungent principles of ginger —zingerone, gingerol and shogaol— are synthesized starting with vanillin in good yields by utilizing the Lewis acid-promoted cross aldol reaction in each key step.
Thermal Decarbonylation of Tropone
Authors: Amano Akira , Mukai Toshio , Nakazawa Tomoo , Okayama Kiyoaki
Published: July 2006

Thermal reaction of tropone has been studied at temperatures ranging from 420 to 490 °C and at residence times ranging from 1.5 to 6.9 s using a conventional flow apparatus. Tropone undergoes first-order unimolecular decarbonylation. The value of kinetic parameters for this reaction are evaluated as being: A=1014.2s−1, Ea=54.1 kcal mol−1, ΔS\eweq=2.8 eu, ΔH\eweq=52.6 kcal mol−1, and ΔG\eweq=50.6 kcal mol−1. These values indicate that the decarbonylation takes place by one-step concerted mechanism via a norcaradienone-like transition complex. The latter complex is characterized by a partial transannular C2–C7 bond formation and concerted elongation of C1–C2 and C1–C7 bonds in tropone. The proposed transition complex is in conformity with reported thermal behavior of 1,3,5-cycloheptatriene as well as with molecular orbital symmetry theory.
Viscosity B Coefficients for Di- and Trialkylammonium Chlorides in Aqueous Solutions
Authors: Tamaki Kunio , Kushida Mitsuyoshi , Ohara Y\={o}ko
Published: July 2006

The viscosity B coefficients of the Jones-Dole equation for di-n-alkylammonium chlorides (methyl to butyl) and tri-n-alkylammonium chlorides (methyl to propyl) in water at 25 °C were determined, and the effect of structural changes in the solvent water induced by the alkyl-substituted ammonium ions is discussed.
The Cycloaddition of 1,2,4,5-Tetrazines with Indoles. The Formation of 5H-Pyridazino[4,5-b]indoles
Authors: Takahashi Masahiko , Ishida Hiroyuki , Kohmoto Masao
Published: July 2006

The cycloaddition of 3,6-disubstituted 1,2,4,5-tetrazines (1) with indoles (2) gave 1,4-disubstituted 5H-pyridazino[4,5-b]indoles (4).
Infrared Absorption Spectrum of Gaseous CF3CO Radical; Recording on a Rapid-Scan Infrared Spectrometer
Authors: Kozuka Muneteru , Isobe Taro
Published: July 2006

A rapid-scan infrared spectrometer capable of scanning the region from 5000 to 650 cm−1 in 200 μs was constructed and successfully applied to study CF3CO radical produced by flash photolysis. Four absorption bands of the radical were detected at 1574, 1338, 1115, and 1024 cm−1 for scanning started 25 μs after the firing of a Xe flash tube. They were tentatively assigned to the CO stretching, CF3 stretching (a species), CF3 stretching (e species), and CC stretching vibrations, respectively.
Finite Element Approach to the Vibrational Schrödinger Equation of Diatomic Species
Authors: Arai Hideyuki , Kanesaka Isao , Kagawa Yukio
Published: July 2006

The finite element approach was successfully applied to the vibrational Schrödinger equation of diatomic species. An O2 molecule with a harmonic potential and an Ar2 molecule with a Lennard-Jones potential were examined and their eigen values and the associated eigen function were obtained. The calculated eigen values of the O2 molecule agree with those expected. In the case of the Ar2 molecule the calculated eigen values agree with those experimentally obtained when Lennard-Jones parameters are ε=115.1 (cm−1) and σ=3.35 (Å). This verifies the validity of the present approach.
The Crystal Structure of the Intermolecular Complex between 9-Ethyladenine and Indole
Authors: Kaneda Tsuguhiro , Tanaka Jiro
Published: July 2006

The crystal structure of a 1: 1 complex of 9-ethyladenine and indole has been determined by the X-ray method. The crystal system is monoclinic with the space group of P21/c. The cell dimensions are a=15.712(2), b=8.098(1), c=11.838(1)Å, and β=103.90(1)°C. Adenines form walls made of double layer. An overlap of adenines is found between layers. The adenine molecule in the front layer is found to be joined by the hydrogen bond with the molecule in the back layer. An intermolecular hydrogen bond is found between adenine and indole rings. The significance of these observations in the interaction of adenine with tryptophan in biological systems is discussed.
Topological Index as Applied to π-Electronic Systems. IV. On the Topological Factors Causing Non-Uniform π-Electron Charge Distribution in Non-Alternant Hydrocarbons
Authors: Gutman Ivan , Yamaguchi Tamië , Hosoya Haruo
Published: July 2006

The topological factors which cause non-uniform π-electron charge distribution in non-alternant hydrocarbons (NAH′s) are discussed. For estimating and analyzing the net-charge density a novel topological index, topological charge density, QrT, is proposed. It is defined as QrT=Re(FG,r(1)), the real part of FG,r(y)=Δr,r(iy)⁄Δ(iy), where Δ(x) is the secular determinant of graph G and Δr,r(x) is its adjunct with row r and column r struck out. This quantity QrT, corresponding to the Coulson net charge density Qr=1−qr, is related with the topological indices \widetildeZG and \widetildeYG which are defined in terms of the coefficients of the characteristic polynomial of graph G. As all the newly proposed indices can be enumerated graphically, one can easily estimate the net-charge densities of NAH′s.
Preparative and Magnetic Studies of Several Binuclear Copper(II) Alkanoate Complexes with Salicylideneamines
Authors: Tokii Tadashi , Muto Yoneichiro
Published: July 2006

Compounds with the stoichiometry of Cu(5-R″-sal·N–R)R′COO (5-R″-sal·N–=·\overset2O·C6H3(\overset5R″)·\overset1CH=N–; R= methyl, phenyl, o-tolyl and p-tolyl; R′=ethyl, monochloromethyl and dichloromethyl; R″=H, CH3 and Cl) have been prepared, and their magnetic and spectral properties have been studied. The magnetic and IR spectral data of the compounds where R=methyl and o-tolyl, R′=dichloromethyl, and R″=H indicate that they have phenolic oxygen-bridged dimer units in their crystals. On the other hand, a carboxylate-bridged binuclear structure is postulated for the other complexes on the basis of magnetic and IR spectral data. It has been observed that, in the latter group of complexes, both the −2J(singlet-triplet separation) and νmax (ligand-field transition energy) values decrease in the order of Cu(Sal·N–R)C2H5COO>Cu(Sal·N–R)ClCH2COO>Cu(Sal·N–R)Cl2CHCOO, where Sal·N–=·\overset2O·C6H4·\overset1CH=N–. The preparation and characterization of the Cu(Sal·N–R)HCOO·DMF compounds (R=p-tolyl and p-chlorophenyl; DMF=N,N-dimethylformamide) are also reported.
Kinetic Study on Dimerization of Chlorotris(triphenylphosphine)rhodium(I) in Benzene
Authors: Ohtani Yoshimi , Fujimoto Masatoshi , Yamagishi Akihiko
Published: July 2006

The monomer-dimer equilibrium of RhCl(PPh3)3 in benzene has been studied with a stopped-flow apparatus under He gas pressure. The decomposition rate of a dimer, [RhCl(PPh3)2]2, obeys pseudo-first-order kinetics with respect to the concentration of PPh3, whereas the formation rate of a dimer obtained by diluting an equilibrium solution with benzene depends on the equilibrium concentration of a monomer, a dimer and PPh3 in a complexed manner. The kinetic results are consistent with the following mechanism; 2RhCl(PPh3)3\ightleftarrowsRhCl(PPh3)2+RhCl(PPh3)3+PPh3\ightleftarrows[RhCl(PPh3)2]2+2PPh3.
Study of Organo(2,2′-bipyridine)nickel Complexes. III. NMR Studies on the Interaction of Dialkyl(2,2′-bipyridine)nickel with Solvents and Olefins
Authors: Yamamoto Takakazu , Nakamura Yoshiyuki , Yamamoto Akio
Published: July 2006

The 1H-NMR spectra of NiR2(bpy)(bpy=2,2′-bipyridine; R=CH3, C2H5, and C3H7) and Ni(C2H5)2(bpy)–olefin systems (olefin=acrylonitrile and acrylaldehyde) have been studied in a temperature range from −70 °C to 80 °C. The temperature dependence of the chemical shifts of ethyl and 2,2′-bipyridine protons of Ni(C2H5)2-(bpy) in non-aromatic solvents (acetonitrile, N,N-dimethylformamide, acetone and tetrahydrofuran) is analyzed on the basis of the formation of 1: 1 solvent-solute complex. The formation constant of the 1: 1 comples, K1, and the thermodynamic parameters ΔF1°, ΔH1°, and ΔS1° are given. The NMR spectra of NiR2(bpy) in aromatic solvents show the aromatic induced solvent shifts, and the chemical shifts of CH2 and CH3 of Ni(C2H5)2(bpy) coincide at 76 °C in benzene to give a sharp singlet peak. The 13C-NMR spectrum of Ni(C2H5)2(bpy) in benzene shows a triplet at 10.63 ppm (CH2, J(13C–H)=132 Hz) and a quartet at 15.97 ppm (CH3, J(13C–H)=128 Hz). The formation constant of Ni(C2H5)2(bpy)(olefin), K2, and the thermodynamic parameters, ΔF2°, ΔH2°, and ΔS2° have been obtained from the temperature dependence of the NMR spectra of the Ni(C2H5)(bpy)–olefin systems. The values of the chemical shift differences between CH2 and CH3 (Δ=δCH2–δCH3) for Ni(C2H5)2(bpy), Ni(C2H5)2-(bpy) (acrylaldehyde), and Ni(C2H5)2(bpy)(acrylonitrile) are −0.30, 0.94 and 0.83, respectively. The increase of the values of Δ by the coordination of the electronegative olefins with nickel is regarded as indicating the increase of the electronegativity of nickel due to the back-donation from nickel to the olefin.
Alkaloids of Rhazya stricta Decaisne: Studies on Rhazinaline and Geissoschizine
Authors: Chatterjee Asima , Banerji Avijit , Majumder Priyalal , Majumder Rekha
Published: July 2006

Chemical investigation of the basic principles of the leaves of Rhazya stricta Decaisne led to the isolation of a number of indolic bases. The studies on two of these, viz., rhazinaline and geissoschizine are described. Rhazinaline, a new alkaloid, has been characterised as 16-formyl-16-epistrictamine. A detailed spectroscopical study of geissoschizine, which had not been previously isolated from a plant source, was carried out confirming the previous structural assignment. The isolation of this alkaloid from a plant source is important from a biogenetic viewpoint, since geissoschizine is one of the key preformed intermediates in the biosynthesis of C19–C20 indole alkaloids.
Rearrangement of 5-Isopropenyl-2-norbornene to 5-Methyl-3a,4,7,7a-tetrahydro-1H-indene
Authors: Iwase Shoji , Nakata Michihiro , Hamanaka Sawako , Ogawa Masaya
Published: July 2006

The Diels-Alder reaction between cyclopentadiene and isoprene gave predominantly endo- and exo-5-isopropenyl-2-norbornenes and also cis-5-methyltetrahydro-1H-indene produced from the endo-product by Cope rearrangement.
The Structure of the Cyclodextrin Complex. III. The Crystal Structure of the α-Cyclodextrin-Sodium Benzenesulfonate Complex
Authors: Harata Kazuaki
Published: July 2006

The crystal structure of the α-cyclodextrin-sodium benzenesulfonate complex, which has a channel-type structure, was determined by X-ray analysis. The crystals were orthorhombic with the space group of P21212, cell dimensions of a=21.832(3), b=16.529(2), and c=8.356(1) Å, and Z=2. The structure was determined on the basis of 2894 diffractometer data and refined by the block-diagonal least-squares methods to the final R-value of 0.069. The benzenesulfonate anion is arranged in the channel which is formed by the stack of α-cyclodextrin rings along the c axis. The benzene ring is located in the cavity, while the sulfonato group is hydrogen-bonded to the primary hydroxyl groups of the adjacent α-cyclodextrin molecule. The space outside the channel is filled with water molecules and sodium ions, and the hydrogen-bonding network is formed. The energy of the complex formation was calculated for two possible structures of the 1 : 1 complex in an aqueous solution.
Preparation and Stereochemistry of a New Isomer (Λ-cis-β) of Cobalt(III) Complexes with (3S,8S)-3,8-Dimethyl-1,4,7,10-tetraazadecane
Authors: Saburi Masahiko , Sato Teiji , Yoshikawa Sadao
Published: July 2006

Carbonatocobalt(III) complex of (3S,8S)-3,8-dimethyl-1,4,7,10-tetraazadecane((3S,8S)-dimetrien) was prepared from trans-[CoCl2(3S,8S)-dimetrien)]ClO4 by treating with carbonate or hydrogencarbonate ion. The carbonato complex was assigned to the Λ-cis-β configuration, a novel geometry for the (3S,8S)-dimetrien complexes. The visible absorption, circular dichroism, and proton magnetic resonance data were obtained for the Λ-β and other carbonato complexes. Preparation and assignment of dinitrocobalt(III) complex with (3S,8S)-dimetrien are given. The relative stabilities of the four isomers of (3S,8S)-dimetrien complexes (Λ-cis-α, Λ-cis-β, Δ-cis-β, and trans) are discussed qualitatively.
Studies of the Mixed Amino Acid Complexes of Cobalt(III). IV. Magnetic Circular Dichroism Spectra of the [Co(ox)x(gly)y(en)z] Complexes
Authors: Matsuoka Nobuko , Shimura Yoichi
Published: July 2006

Magnetic circular dichroism (MCD) spectra of a series of sixteen complexes of the [Co(ox)x(gly)y(en)z] type have been measured. The MCD intensity increases with increasing number of the coordinated carboxylato groups. A negative MCD band whose shape is similar to the corresponding absorption band was observed in the first d-d absorption band region. This negative band is assigned to the “B” term, in which the “A” term is swamped. A positive and a negative MCD band appear in the second d-d absorption band region. The origin of the positive band is discussed.
pH-Dependency of Photocyclization of Diarylfumaronitriles
Authors: Ichimura Kunihiro , Watanabe Shoji
Published: July 2006

The photocyclization of diarylfumaronitriles in aqueous ethanol is influenced by pH. The product ratio of 9,10-dihydro-9,10-dicyanophenanthrenes (IV) decreases with decrease in pH. Discussion is given on the acid-catalyzed isomerization of the 4a,4b-dihydrophenanthrenes to IV from results of observation of the colored intermediate.
Studies of Sulfonyl Radicals. II. Relative Reactivities of Addition Reactions of Sulfonyl Free Radicals to Vinyl Monomers
Authors: Takahara Yoshiyuki , Iino Masashi , Matsuda Minoru
Published: July 2006

Addition reactions of various vinyl monomers towards the free methanesulfonyl and arenesulfonyl radicals have been investigated. Relative reactivities of p-methylstyrene (M2) to styrene (M1) towards methane- and para-substituted benzenesulfonyl radicals are hardly affected by the kind of sulfonyl radical, suggesting that an unpaired electron of methanesulfonyl and arenesulfonyl radicals is localized mainly on sulfonyl groups. Relative reactivities obtained with vinyl monomers were correlated to Hammett’s σp values with ρp=−3.6 and also to Alfrey-Price’s e values, indicating that sulfonyl radicals are strongly electrophilic. The highest selectivity of the benzenesulfonyl radical, obtained in the comparison of the selectivity of a number of radicals in addition reactions towards three representative monomers (Table 5), also supports the above conclusion.
The Bromination and the Mercuration of Bis(dimethylglyoximato)(styryl)pyridinecobalts(III), Styryl-type Cobaloximes
Authors: Shinozaki Hiraku , Kubota Minoru , Yagi Osamu , Tada Masaru
Published: July 2006

cis and trans-p-Cyanostyryl(pyridine) cobaloximes (I and II) and cis and trans-p-methoxystyryl(pyridine)cobaloximes (V and VI) were prepared by the reaction of the reduced form of cobaloxime, bis(dimethylglyoximato)(pyridine) cobalt(I), with cis and trans-p-cyanostyryl bromides and with cis and trans-p-methoxystyryl bromides, respectively. The styryl-type cobaloximes thus obtained retained the stereochemistry, cis or trans, of the starting bromides. The bromination of these styryl-type cobaloximes (I, II, V, and VI) and of the cis and trans-styryl(pyridine)cobaloximes (III and IV) in polar or non-polar solvents gave styryl-type bromides with the retention of configuration. The mercuration of these cobaloximes with mercury(II) acetate in DMF gave styryl-type mercurials, again retaining the original configuration.
The Formation and Reaction of Carbonyl Ylide. The Copper Chelate-catalyzed Decomposition of 1-(Diazoacetyl)fluorenone in the Presence of Ethylenic and Acetylenic Compounds
Authors: Ibata Toshikazu , Motoyama Tadayuki , Hamaguchi Masashi
Published: July 2006

1,3-Dipolar cycloadducts were obtained by the copper chelate-catalyzed decomposition of 1-(diazoacetyl)fluorenone in the presence of acetylenic and ethylenic dipolarophiles. The reaction proceeded via intermediate carbonyl ylide (3), which has been generated by the carbene-carbonyl reaction of 2. The cycloaddition of 3 with ethylenic dipolarophiles was determined to proce d stereospecifically.
The Photochemical Sulfenylation of Halides with Organic Disulfides
Authors: Fujisawa Tamotsu , Ohta Hiromichi
Published: July 2006

The reaction of organic disulfides with aryl radicals photochemically generated from aryl halides was investigated. Diaryl sulfides were obtained from diaryl disulfides when the radiation was provided by a low-pressure mercury lamp, while dialkyl disulfides afforded alkyl aryl sulfides whether the radiation source was a low- or a high-pressure mercury lamp.
Rotational Isomerism and Intermolecular Interaction in the Liquid Phase
Authors: Fujiyama Tsunetake , Kakimoto Masao
Published: July 2006

The Raman intensities of some fundamental lines of 1,2-dichloroethane and 1,2-dibromoethane and related molecules with internal rotation axes were observed at various temperatures. The observed relative intensities were corrected for some systematic errors expected in the intensity measurement. The importance of a local-field effect was emphasized. The van’t Hoff plot of the observed intensity ratios of the trans and gauche isomers showed the existence of strong intermolecular interactions in the liquid phase. The intermolecular interaction energy in the liquid phase was theoretically estimated from both the macroscopic and microscopic points of view. The usefulness of a dipole-dipole interaction model was emphasized.
Equilibrium Dialysis Studies of the DNA-Acridine Complexes
Authors: Kubota Yukio , Eguchi Yoshio , Hashimoto Kazumasa , Wakita Masaaki , Honda Yumi , Fujisaki Yasuo
Published: July 2006

The strong binding of acridine dyes with DNA was studied by means of equilibrium dialysis. Ten acridine derivatives were used to elucidate the effect of the dye structure on the nature of strong binding. In the strong binding, up to one dye molecule per 4–6 nucleotides was bound with the change of free energy in 5–9 kcal mol−1. The introduction of bulky groups to the 10 or 3,6-positions of the acridine ring led to a marked decrease in both the association constant and the maximum number of binding sites per DNA phosphate. These findings suggest that, when a dye molecule is intercalated, the dye is located in such a way that the bulky groups attached to the acridine ring produce some steric hindrance to the binding.
Studies of Iron(II) Complexes with Several Schiff Bases: New Examples of 5T2-1A1 Equilibrium
Authors: Maeda Yonezo , Takashima Yoshimasa , Nishida Yuzo
Published: July 2006

Iron complexes with the Schiff bases of quinolinecarbaldehyde and pyridinecarbaldehyde were prepared. Mössbauer spectra and magnetic susceptibilities of the compounds, Fe(pipa)2(NCS)2, Fe(pa)2(NCS)2, Fe(pot)2(NCS)2·1/2CHCl3, Fe(ppt)2(NCS)2, Fe(ppca)2(NCS)2, and Fe(ppa)2(NCS)2 were studied in the temperature range between 298 and 27 K. It was found that these complexes showed an incomplete 5T2-1A1 transition in the solid. The compound Fe(poca)2(NCS)2 also showed a similar phenomenon. The observations of the behavior of the various complexes indicated that the magnetic changeover from spin-paired to spin-free would be closely associated with a modification of the crystal lattice. The FeL′Cl2(L′: the Schiff bases of quinolinecarbaldehyde) were found to have distorted tetrahedral structures.
The Kinetic Study of the Oxidation Reaction of the Tris(2,2′-bipyridine)cobalt(II) Ion and the Ethylenediamine-N,N,N′,N′-tetraacetato cobaltate(II) Ion by the Peroxodisulfate Ion
Authors: Ohashi Kousaburo , Matsuzawa Morito , Hamano Eichi , Yamamoto Katsumi
Published: July 2006

The kinetics of the oxidation of CoII–EDTA and CoII(bpy)32+ by the peroxodisulfate ion (S2O82−) in acidic media have been studied spectrophotometrically; EDTA and bpy represent ethylenediamine-N,N,N′,N′-tetraacetic acid and 2,2′-bipyridine respectively. The stoichiometry of the reactions of CoII–EDTA with the peroxodisulfate ion was 2CoII–EDTA+S2O82−=2CoII(edta)−+2SO42−. The rate for the oxidation of CoII–EDTA by the peroxodisulfate ion is independent of the concentration of CoII–EDTA, but first-order dependent with respect to the peroxodisulfate-ion concentration. The rate law is d[CoII(edta)−]/dt=2k[S2O82−]. The rate-determining step must be the decomposition of S2O82− into 2SO4\ewdot. The first-order rate constant, the activation enthalpy, and the activation entropy are 5.5×10−8 s−1, 24 kcal mol−1, and −12 eu respectively at pH 3.60, 25 °C, and I=0.50 (NaClO4). Two moles of CoII(bpy)32+ are oxidized by one mole of the peroxodisulfate ion. For the oxidation of CoII(bpy)32+, the following reaction path and rate law were proposed:

& Co^II(bpy)_3^2++S_3O_8^2-\oversetk_e\ightleftarrows[Co^II(bpy)_3^2+·S_2O_8^2-]\xrightarrowkCo^II(bpy)_3^3++SO_4^2-+SO_4^\ewdot

& Co^II(bpy)_3^2++SO_4^\ewdot\xrightarrowfastCo^III(bpy)_3^3++SO_4^2-

& \fracd[Co^II(bpy)_3^3+]dt=\left{\frac2k·K_e1+K_e[S_2O_8^2-]\ight}[S_2O_8^2-][Co^II(bpy)_3^3+]_T

At pH 3.60, 25 °C, and I=0.50 (Na2SO4), the rate constant, k, and the equilibrium constant, Ke, are 0.53 s−1 and 5.6 M−1 respectively. The difference in the rate law and mechanism between CoII–EDTA and CoII–(bpy)32+ may come from the difference in charge on the cobalt(II) complexes.
Halogenation and Nitration of Some Mixed Ligand Acetylacetonato cobalt(III) Complexes
Authors: Kuroda Kashiro , Yoshitani Kouzou , Kunigita Kazufumi , Kamiiba Yukiko , Watanabe Kiyokatsu
Published: July 2006

In six kinds of mixed ligand acetylacetonatocobalt(III) complexes ((NH3)4-, (en)2-, α-trien-, β-trien-, fac(N)-i-dtma-, and mer(N)-i-dtma-complexes), the methine hydrogen of the coordinated acetylacetonate ion has been substituted with chlorine, bromine, and iodine, and in five of them excepting the mer(N)-i-dtma complex, it has been substituted with a nitro group. The halogenated and the nitrated complexes were isolated and identified by means of electronic absorption spectra and NMR spectra. The effects of the substitutions on the properties and the characteristics of the substitution reactions are described and discussed.
Equilibria of Complex Formation in Aqueous Solution between Lead(II) and Thallium(I) Ions, and Cyclic and Linear Poly ethers
Authors: Kodama Mutsuo , Kimura Eiichi
Published: July 2006

logK, ΔH and ΔS values were polarographically determined for the interaction in aqueous solution of Pb2+ and Tl+ ions with a cyclic polyether, 1,4,7,10,13,16-hexaoxacyclooctadecane(18-crown-6), and a linear polyether, tetraethylene glycol dimethyl ether (tetraglyme). The stability constant of a 1:1 Pb2+ complex with the macrocyclic ligand is four figures higher than that with the linear ligand. This macrocyclic effect is explained in terms of entropy.
Preparation and Reactions of 4-Alkoxy-2,2-bis(trifluoromethyl)thietanes and 5-Alkoxy-3,3-bis(trifluoromethyl)dithiolanes
Authors: Kitazume Tomoya , Otaka Toru , Takei Ryutaro , Ishikawa Nobuo
Published: July 2006

4-Alkoxy-2,2-bis(trifluoromethyl)thietanes, 3 (R=Me and Et), were prepared by the reactions of 2,2,4,4-tetrakis(trifluoromethyl)-1,-dithietane with alkyl vinyl ethers in a KF–DMF system. A bimolecular condensation product, bis[4,4-bis(trifluoromethyl)thietan-2-yl]ether, 5, was obtained by the treatment of 3 with concentrated sulfuric acid. On the other hand, when treated with sulfur in DMF in the presence of diethylamine, 3 gave 5-alkoxy-3,3-bis(trifluoromethyl)-1,2-dithiolanes, 8, in rather good yields. Several reactions of these thietanes and 1,2-dithiolanes, including those with butyllithium, were examined.
Carbonization of Aromatic Hydrocarbons. II. Carbonization of Modified Pyrene in the Presence of Aluminum Chloride
Authors: Mochida Isao , Fukuda Noriyoshi , Maeda Keiko , Takeshita Kenjiro
Published: July 2006

The carbonization of four hydrogenated and two methylated pyrene derivatives in the presence of aluminum chloride was investigated to elucidate the effects of the slight structural perturbation on the carbonization properties of pyrene. Hexahydropyrene was found to give coke having a needle-like structure via similar carbonization steps as naphthalene followed. In contrast, dihydropyrene formed coke of a mosaic structure for the most part. Although 1-methylpyrene produced coke with a needle-like structure, in part, reductively methylated pyrene was converted to a mosaic structure as was pyrene. In the case of needle-coke formation, the carbonization process of hydrogenated and methylated pyrene followed the steps of appearance, growth and coalescence of anisotropic spheres where the reaction started at a lower temperature and proceeded more moderately compared with the case of pyrene. It is thus indicated that a partially lowered aromaticity of pyrene may favor its carbonization into needle coke.
The Solubilities and Kraft Points of Fatty Acid Soaps of Odd Carbon Numbers
Authors: Ogino Keizo , Ichikawa Yukinori
Published: July 2006

The solubilities of sodium soaps of odd carbon-number fatty acids were measured at various temperatures and the Kraft points of the soaps were determined from the phase diagrams showing the temperature dependence of equilibria among monomers, micelles, and hydrated solid. It was found that the Kraft points were related with the carbon numbers of the fatty acids in a zig-zag curve.
Preparation and Geometrical Isomers of Cobalt(III) Complexes with Tridentate O–S–O Ligand Thiodiacetate or 3,3′-Thiodipropionate
Authors: Kanamori Kan , Sudani Tokiko , Kawai Kiyoyasu
Published: July 2006

cis(S)-fac- and trans(S)-fac-Isomers of bis(thiodiacetato)cobaltate(III), trans(O)-mer-, s-cis(O)-fac- and u-cis(O)-fac-isomers of (thiodiacetato)(diethylenetriamine)cobalt(III) and trans(O)-mer-isomer of (3,3′-thiodipropionato)(diethylenetriamine)cobalt(III) were prepared. Their geometrical configurations were assigned on the basis of their absorption and PMR spectra. The stereochemistry of the Co(III) complex with a tridentate ligand thiodiacetate is similar to that of the Co(III) complex with iminodiacetate.
The Vibrational Spectra and Rotational Isomerism of Chloro(chloromethyl)silanes
Authors: Sera Keiichi , Suehiro Keigo , Hayashi Michiro , Murata Hiromu
Published: July 2006

The infrared spectra of chloro(chloromethyl)methylsilanes ClCH2SiCl3−n(CH3)n (n=0–2) in the liquid and crystalline states and a part of the Raman spectra in the liquid state have been measured. It has become apparent that, for ClCH2SiCl2CH3 and ClCH2SiCl(CH3)2, two rotational isomers coexist in the liquid state, while only one isomer persists in the crystalline state. The fundamental vibrations for these molecules have been assigned, and the normal vibrations have been calculated on the basis of a modified Urey-Bradley force field. The solvent effects and the calculation of the normal vibrations have indicated that the gauche form for ClCH2SiCl2CH3 and the trans form for ClCH2SiCl(CH3)2 persist in the crystalline state. For ClCH2SiCl3, the barrier height, V3(SiCl3), has been estimated to be 4.6 kcal/mol from the torsional force constant.
The Partial Molar Volumes of Normal Alkanols in Aqueous Sodium Dodecyl Sulfate Solutions
Authors: Manabe Masahiro , Shirahama Keishiro , Koda Masaharu
Published: July 2006

The partial molar volumes of normal alkanols (CmH2m+1OH, m=1–10) in aqueous sodium dodecyl sulfate solutions were measured by a dilatometric method at 25 °C. For the alkanols (m=4–8), different constant partial molar volumes appeared below and above the CMC value, whereas no such difference was observed for lower alkanols (m=1–3), and for higher alkanols (m=8–10) the partial molar volumes above the CMC value are nearly identical with their own molar volumes. The partition coefficient of the alkanols between the bulk and micellar phases is estimated on the basis of the volumetric results.