bluuebunny/crossref_metadata_2025 huggingface dataset:
The Intermolecular Potential of Hydrocarbon Dimers as Examined by the Perturbation Theory Including Exchange Energy in the PPP Approximation
Authors: Fujita Hiroko , Imamura Akira
Published: July 2006

By using the perturbation method, including the exchange energy, the interaction potential curves for the intermolecular distances from 2.0 Å to 6.0 Å of the ethylene dimer, the butadiene dimer, the hexatriene dimer, and the benzene dimer were obtained. The matrix elements were evaluated in the Pariser-Parr-Pople approximation. Reasonable intermolecular potential curves were obtained for all the dimers studied. The analysis of the perturbation energy leads to the conclusion that the induction and dispersion energies and the exchange repulsion energy of the second order in the overlap integral give the potential minimum for the interaction of small molecules, such as ethylene or butadiene dimers, but for large molecules, such as benzene or hexatriene dimers, the exchange repulsion energy of the fourth order in the overlap integral should also be included in order to obtain the potential minimum. An important role of the charge transfer term was suggested for the chemical reaction; this was in agreement with the indications of previous researchers. The calculated depth of the potential minimum and the equilibrium molecular distance are in fairly good agreement with the experimental data.
The Magnetic Properties of Cu3Cl6(C6H7NO)2·2H2O
Authors: Miyoshi Hirokazu , Ohya-Nishiguchi Hiroaki , Deguchi Yasuo
Published: July 2006

From magnetic susceptibility and ESR measurements, it has been confirmed that polybis(μ-(2-picoline N-oxide)-chlorocopper(II)di-μ-chloro)diaquocopper, Cu3Cl6(C6H7NO)2·2H2O, consists of alternating linear chains with diamagnetic Cu2Cl4(C6H7NO)2 units and paramagnetic CuCl2·2H2O units joined by long Cu–Cl bonds. The two copper ions in the Cu2Cl4(C6H7NO)2 unit are coupled together very strongly by antiferromagnetic exchange interaction and occupy almost entirely the diamagnetic singlet state below room temperature. This interpretation is appropriately supported by the observation of a half-field resonance near 1600 Oe in the ESR spectrum of the powdered sample. On the other hand, the copper ion in the CuCl2·2H2O unit isolated magnetically can account for the ESR spectrum due to ΔM=±1 transition and magnetic susceptibility, following the Curie law. The magnetic susceptibility of the dehydrate compound, Cu3Cl6(C6H7NO)2, has also been measured.
The Dehydrogenation of Amines by Molten Metal Catalysts
Authors: Okano Kiyohisa , Saito Yasuo , Ogino Yoshisada
Published: July 2006

In order to investigate the catalytic activity of molten metal, experiments were carried out using the dehydrogenation of n-butylamine, benzylamine, and cyclohexylamine as test reactions. The molten zinc catalyst was thus found to show specially high activities and selectivities in all test reactions. The activity of the molten gallium catalyst for the dehydrogenation of n-butylamine was also considerable. However, the selectivity of this catalyst was somewhat lower than that of the molten zinc catalyst, and considerable amounts of dibutylamine were produced at lower reaction temperatures. The other molten metals were found to be almost inactive. That is, Pb, Cd, Sn, and Bi were inactive, while Tl and In were only slightly active.
Structure of the Vanadium-Potassium Catalyst during the Oxidation of Sulfur Dioxide and the Oxidation Mechanism
Authors: Kato Akio , Tomoda Katsuhiko , Mochida Isao , Seiyama Tetsuro
Published: July 2006

The structure of vanadium-potassium catalyst in gas mixtures of various compositions of SO2, SO3, and O2was investigated at 500, 550, and 600°C to elucidate the mechanism of SO2 oxidation on the catalyst. It was found that in the catalyst 50–70% of V(IV) is in VO2+-form, and the rest of the vanadium forms large vanadium-oxygen networks. It was also found that both the reduction of V(V) with SO2 and oxidation of V(IV) with oxygen are in equilibrium and the desorption of SO3 from the molten catalyst into gas phase seems to be the rate-determining step in SO2 oxidation. On the basis of this mechanism, the reaction rate of SO2 oxidation can be formulated as follows,

dSO3⁄dt=k′(SO3)=kPSO2·PO21⁄2.

For the sake of confirmation, the kinetics of SO2 oxidation (below 10% conversion) over vanadium-potassium catalyst was measured by a flow method at 500, 550, and 600°C over gas compositions of SO2=5∼24% and O2=10∼36%. It was found that the rate expression was correct.
Magnetic Properties of Some Iminoxyl Polyradicals. III. Exchange Interaction in Iminoxyl Biradicals
Authors: Nakajima Akira , Ohya-Nishiguchi Hiroaki , Deguchi Yasuo
Published: July 2006

The EPR spectra of TEMPAD and Sulfite biradicals in a dilute solution have been reasonably interpreted in terms of the variation in the ratio of the intra-molecular exchange interaction to the 14N hyperfine interaction. Comparing these spectra with the theoretical ones, the authors have estimated the intra-molecular exchange interactions as 10.0·A=2×10−2k and 3.0·A=5×10−3k respectively. The magnetic susceptibility of the TEMPAD biradical exhibits a broad maximum at a temperature of 16.5°K, while 50 and 75% TEMPAD diluted in corresponding diamine have no maximum in the temperature range measured. The magnetic susceptibility of the sulfite biradical also shows a broad maximum at 15.0°K, in spite of the weak intra-molecular exchange interaction. These results indicate that the origin of the short-range ordering is the inter-molecular exchange interaction between unpaired electrons in different molecules.
Molecular Structures of Acetyl Chloride and Acetyl Bromide as Determined by Gas Electron Diffraction
Authors: Tsuchiya Shuzo , Kimura Masao
Published: July 2006

The molecular structures of acetyl chloride and acetyl bromide have been investigated by the sector-micro-photometer method of gas-phase electron diffraction. The thermal average distances, rg, and the valence angles, \varphia, have been determined, with estimated limits of error, to be as follows: for acetyl chloride, rg(C=O)=1.187±0.003 Å, rg(C–Cl)=1.798±0.003Å, rg(C–C)=1.508±0.005 Å, \varphia(OCCl)=120.3°±0.6°, \varphia(CCCl)=112.2°±0.09°, and \varphia(CCO)=127.5°±0.9°; and for acetyl bromide, rg(C=O)=1.184±0.004 Å, rg(C–Br)=1.975±0.004 Å, rg(C–C)=1.518±0.008Å, \varphia(OCBr)=120.8°± 0.9°, \varphia(CCBr)=109.5°±1.2°, and \varphia(CCO)=129.7°±1.1°. The C=O distances in these molecules are shorter than those in acetaldehyde and acetone by about 0.02 Å. This may be attributed to the effect of a highly electronegative halogen atom adjacent to the carbonyl group.
Electronic Spectra and Structures of Organic π-Systems. VII. Electronic States of Benzoylium, Acryloylium, and Cinnamoylium Ions
Authors: Yoshida Zen-ichi , Kobayashi Tsunetoshi
Published: July 2006

The electronic states of benzoylium, acryloylium and cinnamoylium ions have been studied by a semiempirical ASMO LCAO SCF CI method including both π- and \barπ-systems.

The results suggest that the contribution of the canonical formula R−–\overset+CO or R–\overset+CO to the ground state in ketene should be smaller than that in benzoylium, acryloylium or cinnamoylium ion. The longest wavelength singlet-singlet transition of benzoylium or cinnamoylium ion is π–1π as in benzenediazonium ion, and that of acryloylium ion is π–1\barπ as in ketene, diazomethane and diazocyclopentadiene.
The Benzene-photosensitized Decomposition of Carbonyl Sulfide in a Cyclohexane Solution
Authors: Sato Shin , Miyamoto Hiroshi , Hirokami Shun-ichi , Tsunashima Shigeru
Published: July 2006

The decomposition of carbonyl sulfide photosensitized by benzene in the solution of cyclohexane has been investigated at room temperature. The quantum yield of CO formation, φCO, at an infinite concentration of COS was estimated to be 1.0. The COS concentration dependence of φCO corresponded well to that of the quenching efficiency of COS on benzene fluorescence. These results suggest that, of the two possible photosensitization processes:

C6H6(1B2u)+COS→C6H6+CO+S(1D)

and

C6H6(3B1u)+COS→C6H6+CO+S(3P),

the former is responsible for the formation of CO. The very small yield of cyclohexanethiol may be explained by the fact that benzene is an efficient catalyzer for the transition process, S(1D)→S(3P).
Amino Wagging of the tert-Butylamine in Ã Electronic State
Authors: Hirakawa Akiko Y , Miyazaki Hideyuki , Tsuboi Masamichi
Published: July 2006

Ultraviolet absorption spectra of two isotopic t-butylamines, (CH3)3CNH2 and (CH3)3CND2, have been observed in their gaseous state in the spectral region 2000–2500 Å. There is an electronic band, whose 0–0 band peaks are observed respectively at 2351.2 and 2334.9 Å. The vibrational structure of the band, caused by the amino wagging vibration, was analyzed. On the basis of the observed energy levels, the potential function of the excited molecule along the amino wagging coordinate was determined; it is nearly harmonic with a small positive quartic term. The dependence of intensity on the vibrational quantum number and the intensity ratio of the fundamental and the hot bands indicate that the equilibrium structure of the amino group is the same as that of methylamine; the angle between the C–N axis and the HNH plane has been determined to be 51± 4°.
Laser Photolysis Studies on the Formation of Solvated Ion Radicals in the Pyrene–N,N-Dimethylaniline System in Various Solvents
Authors: Taniguchi Yoshio , Nishina Yasuzo , Mataga Noboru
Published: July 2006

Formation of solvated ion radicals in the pyrene-N,N-dimethylaniline (DMA) system (which is a typical one showing heteroexcimer (HE) fluorescence) in various solvents has been studied by means of the laser photolysis and transient photoconductivity as well as transient absorption measurements. Ion radical formation due to the encounter collision between an excited pyrene and DMA in moderately as well as in strongly polar solvents has been established. This result is quite important in explaining the experimentally observed relation between the solvent dependent HE fluorescence quantum yield and decay time.
Copper(II) Chelates of 2,4,6-Heptanetrione and Its Homologues
Authors: Sagara Fumio , Kobayashi Hiroshi , Ueno Keihei
Published: July 2006

Copper(II) chelates of heptane-2,4,6-trione as well as its methylated derivatives such as 3-methylheptane-2,-4,6-trione, 3,5-dimethylheptane-2,4,6-trione, and 2-methoxy-2-heptene-4,6-dione have been synthesized. All the ligands gave 1 : 2 (metal ion: ligand) chelates. The first two ligands gave in addition binuclear 2 : 2 chelates. The fact that a 1 : 2 chelate was relatively easily converted into a 2 : 2 chelate and the conversion occurred more easily with the chelate of the first ligand than with that of the second one was interpreted by the steric effect of the methyl group. The structures of the 1 : 2 and 2 : 2 chelates were discussed on the basis of spectroscopic and other data. Reversible addition of heterocyclic bases to the 2 : 2 copper chelates was observed, and the coordinating structure of pyridine adduct was found to be of a pentacoordinate square pyramid.
Partial Pressures of Strontium and Strontium Oxide over Strontium Oxide Heated on Platinum
Authors: Asano Mitsuru , Yamamoto Yutaka , Sasaki Noriaki , Kubo Kenji
Published: July 2006

A quadrupole mass filter was used to determine the partial pressures of Sr(g) and SrO(g) over strontium oxide heated on a platinum-ribbon filament. The ion currents of 88Sr+ and 88Sr16O+ were measured while the filament temperature was continuously increasing at a heating rate of about 14°C/min; the calculations of the partial pressures were carried out by the integral method for Sr(g) and by the sensitivity-calibration method for SrO(g). The data are represented by:

logPSr(g)(atm)=6.633−\frac2.536×104T

in the temperature range of 1643–1851°K, and by:

logPSrO(g)(atm)=6.707−\frac2.793×104T

in the 1747–1850°K range. From the values of the partial pressures, the dissociation energy of strontium oxide was determined to be D0°(SrO)=96.2±0.9 kcal/mol by the third-law treatment and D0°(SrO)=102±5 kcal/mol by the second-law treatment.
The Apparent Molar Volumes of Tetraalkylammonium Halides in Liquid Sulfur Dioxide
Authors: Uosaki Kohei , Kondo Yasuhiko , Tokura Niichiro
Published: July 2006

The apparent molar volumes, Φv, of tetraalkylammonium halides, R4NX (R=Me, Et, n-Pr, and n-Bu; X=Br− and I−), have been determined in liquid sulfur dioxide at several concentrations, and from these values the apparent molar volumes at an infinit dilution, Φv°, have been obtained for these salt at 25°C. The results indicate that, for all the salts, the Φv vs. \sqrtc curves are almost straight over the concentration ranges studied. The slopes of the plots have large positive values for all the salts in this solvent. In order to study the ion-solvent interaction, the apparent molar volumes of the individual ions at an infinit dilution have been determined from those values by Conway’s method. While the Φv° values of tetraalkylammonium ions are similar to those in other solvents, the Φv° values of bromide and of iodide ions in this solvent are quit small compared with those in other solvents. The results can be explained in terms of a strong anion-solvent interaction in liquid sulfur dioxide resulting from the formation of a charge-transfer complex of the halide ion with sulfur dioxide.
Linear Conjugated Systems Bearing Aromatic Terminal Groups. VII. Syntheses and Electronic Spectra of 1,1′- and 2,2′-Dipyrenylpoly-ynes
Authors: Nakasuji Kazuhiro , Akiyama Shuzo , Nakagawa Masazumi
Published: July 2006

1,1′- and 2,2′-Dipyrenylpoly-ynes (In and IIn, n=1–6) have been synthesized. It was found that the bathochromic shift of the longest-wavelength absorption maxima (λL) according to the increase in the number of acetylenic bond (n) can be well expressed by the following formulas:

In:λL=3.7n1.7+430 (nm in toluene)

In:λL=12.6n1.4+327 (nm in toluene)
Linear Conjugated Systems Bearing Aromatic Terminal Groups. VIII. Syntheses and Electronic Spectra of Bis(4-biphenylyl)- and 2,2′-Difluorenylpoly-ynes
Authors: Nakasuji Kazuhiro , Akiyama Shuzo , Nakagawa Masazumi
Published: July 2006

In order to get further information on the effect of terminal groups on the spectral regularity of diarylpoly-ynes, we carried out the syntheses of bis(4-biphenylyl)poly-ynes (In, n=1–6) and 2,2′-difluorenylpoly-ynes (IIn, n=1–4 and 6). The bathochromic shift of the longest-wavelength absorption maxima (λL) along with the increase in n was found to be expressed by the following empirical formulas:

In:λL=24.0n1.1+304 (nm in tetrahydrofuran)

IIn:λL=9.0n1.5+350 (nm in tetrahydrofuran)

The spectral behavior of bis(4-biphenylyl)poly-ynes (In) strongly supported the relationship λL∝n in diphenylpoly-ynes.
Asymmetric Reactions. VII. Stereoselectivities in Phenyllithium and Grignard Reactions with Tetrahydrofurfural Derivatives
Authors: Yoshimura Juji , Ohgo Yoshiaki , Ajisaka Katsumi , Konda Yaeko
Published: July 2006

Stereoselectivities in the phenyllithium and phenylmagnesium bromide reactions with tetrahydrofurfural (1), its diacetate (2) and 5,5-dimethyl-(S)-tetrahydrofurfural (3) were examined, in order to clarify the cause of anomalous stereoselectivity of Grignard reactions with N-substituted 2,3-O-isopropylidene-d-glyceraldimine and the carbonyl analogue (giving erythro product predominantly). The presumption that the anomalous stereoselectivity might be caused by coordination ability of magnesium to C3-oxygen, together with C1-oxygen or C1-nitrogen, and C2-oxygen, was solidified from the present results that no stereoselectivity difference was observed between both reactions with substrates having no C3-oxygen. Detailed discussion on the stereoselectivity differences between substrates was also made.
The Microwave Spectrum of Dimethyl Sulfone
Authors: Saito Shuji , Makino Fumio
Published: July 2006

The microwave spectra of normal and 13C-isotopic species of dimethyl sulfone have been investigated, and the rotational constants of both species have been determined. The following r0-structural parameters have been determined: r(C–S)=1.777±0.006Å, r(S–O)=1.431±0.004Å, ∠CSC=103°17′±10′, and ∠OSO=121°1′±15′, assuming that r(C–H)=1.091Å and ∠HCH=109°34′. The variations in the structural parameters among the related alkyl sulfides, alkyl sulfoxides, and alkyl sulfones have been discussed. The dipole moment has been determined to be μ=4.432±0.041 D along the b axis. This value is consistent with the results of a bond-moment calculation based on the dipole moment of dimethyl sulfoxide.
Low-Frequency Raman Spectra and Phase Transition of the 1,2-Dichloroethane Crystal
Authors: Ozora Akira , Nakagawa Tsugito , Ito Mitsuo
Published: July 2006

In order to study the phase transition of 1,2-dichloroethane crystal at 177°K, the low-frequency Raman spectra were measured at various temperatures, and normal coordinate analysis was carried out. It was found that the phase transition is of rotational type in which the librational motion of the molecule about the axis passing through two chlorine atoms of the molecule changes into a nearly free rotation about the same axis.
Studies of Salt Solution Aerosols. VIII. The Effect of Humidity on the Stability of Spray-dried Na2SO4 Aerosol and an Estimate of the Particle Density
Authors: Ueno Yasuo , Sano Isamu
Published: July 2006

The aerosols obtained by spraying an aqueous Na2SO4 solution of concentrations ranging from 0.1 to 10% by weight were dried by a furnace at 200 to 800°C and were then subjected to stirred aging at room temperature in an atmosphere of 90% relative humidity or less; the variations in both mass concentration and particle size were then measured with the lapse of time.

By employing the results thus obtained and by making some assumptions, the density of the particle in dried aerosols was calculated to be several tenths of one gram per cc, which is smaller by a factor of 3 to 4.5 than the bulk density of solid Na2SO4; further, the amount of water which the dried particle might hold if kept in a humidified atmosphere was estimated, with the finding that the density of a particle would decrease with increase in its water content; for example, the density of the particle with composition of Na2SO4·10H2O would be 0.32 g/cc, smaller by a factor of 4 to 5 than the bulk density. In addition, the influence of water vapor on the stability of the dried aerosols was studied; it was found that the higher the humidity, the greater the rate of coagulation.
Hydrogen Exchange Reactions between Olefins or an Olefin and Molecular Hydrogen over Alumina Studied by Microwave Spectroscopy
Authors: Sakurai Yuzo , Onishi Takaharu , Tamaru Kenzi
Published: July 2006

The exchange reaction between propylene and deuterium was studied over alumina. The rate of the reaction was expressed by Vex=k[PD2]0.5[PPro]0.0. In the initial stages of the reaction the cis- and trans-1 -d1 species of propylene were the only products of the exchange reaction, but the concentration of the 3-d1 species increased continuously as the reaction progressed. The activation energy for the exchange reaction was about 8.2 kcal/mol.

Propylene-cis-d1 was reacted over alumina, and the variation in the deuterium distribution of the propylene was followed by microwave spectroscopy. Isotope scrambling and “double-bond migration” occurred to considerable extents, while cis-trans equilibration between the two C1 hydrogen positions proceeded even faster. In the reaction of propylene-3-d1 the isotope mixing and “double-bond migration” were considerably slower than those of the cis-1-d1 species. Cis- and trans-1-d1 species were formed in equal amounts. The possible mechanism of these reactions is discussed on the basis of the results obtained.
Energy Transfer Concerning the Lowest Triplet State of Tetracyanobenzene with Methyl-Substituted Benzenes
Authors: Kobayashi Takayoshi , Nagakura Saburo
Published: July 2006

The quantum-yield ratios of phosphorescence to fluorescence and the phosphorescence lifetimes were measured for the charge-transfer complexes of tetracyanobenzene with methyl-substituted benzenes. By combining the observed results with the fluorescence quantum yields and lifetimes reported previously, the upper and lower limits of the rate constants for the intersystem crossing and for the radiative and non-radiative energy-transfer processes from the lowest triplet state to the ground state were obtained with the complexes. The intersystemcrossing rate constant of tetracyanobenzene was found to be decreased by the complex formation. This tendency was explained by the mixing of the charge-transfer configuration with the appropriate singlet and triplet states of the component molecules. The phosphorescence radiative rate constant was found to be determined by the contribution of the higher excited singlet configurations of each complex to the phosphorescent state. The temperature dependence of the phosphorescence-quenching rate constant was determined, and the activation energy of the process was interpreted as being due to intramolecular out-of-plane bending vibrations.
Polarized Absorption Spectrum of the Second S→T Transition of Phenazine Crystals
Authors: Mikami Naohiko , Ito Mitsuo
Published: July 2006

Polarized absorption spectrum of the second S→T transition of phenazine single crystal was measured at 4.2°K. The transition moments of the individual vibronic bands were determined uniquely from their polarization characteristics. The 0—0 band at 20470 cm−1 was found to be polarized along the N-N axis of the molecule and assigned as 3B3u←1Ag(n-π*) transition. The vibronic bands other than the 0？0 band was found to be exclusively polarized along the long axis of the molecule, and they were assigned as the vibronic bands induced by a nontotally symmetric vibration in the 3B3u state. The possible routes of vibronic spin orbit coupling mechanism are discussed on the basis of the observed results.
An Additional Formation of CH280BrBr via a Kinetic-energy-independent Process in the Highly Moderated 80mBr-CH4 Systems
Authors: Numakura Kenshi , Saeki Masakatsu , Tachikawa Enzo
Published: July 2006

The moderator effect of Kr on the reaction of (I.T.)-activated 80Br with CH4 has been examined, keeping the ratio of Br2/CH4 at 0.02 or 0.05. The yield of CH280BrBr shows a slight decrease at the beginning of moderation and then tends to increase with further moderation. These facts suggest an additional formation of CH2-80BrBr via a thermal ionic process in highly-moderated systems. When the concentration of Br2 is varied in the system containing 10 cmHg of CH4 and from 40 to 36 cmHg of Kr, the yield of CH280BrBr first increases and then decreases, showing a broad maximum. This dependence not only partly explains the inconsistence of the present results with those previously reported, but also suggests the competition of two types of reaction in its formation. One must be the reaction of a radioactive radical with Br2, leading to the formation of CH280BrBr:

·CH280Br+Br2→CH280BrBr.

The other type of reaction is a scavenging reaction of Br2 for the reacting 80Br atom.
The Crystal and Molecular Structure of meso-2,4-Pentanediol Borate
Authors: Kuribayashi Shunsuke
Published: July 2006

The crystals of meso-2,4-pentanediol borate are monoclinic with a space group of C2/c. There are eight molecules in the unit cell with dimensions of: a=15.36, b=13.53, c=7.68 Å, and β=113.3°. The crystal structure was determined by the X-ray method. The final discrepancy index is 0.121 for 1030 non-zero reflections. The molecule has a six-membered ring composed of one boron, three carbon, and two oxygen atoms. The borate group and the two carbon atoms of the pentane group are nearly co-planar. The five carbon atoms are also co-planar, and they are in trans positions. The molecule was proved to be of the meso type.
Mercury-Photosensitized Decomposition of Ethylbenzene
Authors: Mikuni Hitoshi , Takase Azuma , Murano Motohiro , Takahasi Makoto
Published: July 2006

The decomposition of ethylbenzene sensitized by Hg(3P1) was studied in gas phase. Hydrogen, methane and ethane were obtained as the main gaseous products. Their rates of formation were determined as a function of the pressure of ethylbenzene or xenon. To decide whether methyl or ethyl radical is the primary product in the photolysis, ethylbenzene-β-d1 was photolyzed. It was concluded that methyl radical is the primary product, since methane-d1 and ehane-d2 were obtained as products. A probable reaction mechanism is proposed to interpret the effect of pressure and light intensity on the rate of formation of ethane and methane. It is suggested that a biphotonic process is involved, which can explain the fact that the rate of formation of ethane is proportional to the square of light intensity.
Conductometric Determination of Ion-association Constants for Magnesium and Nickel Sulfates in Aqueous Solutions at Various Temperatures between 0°C and 45°C
Authors: Katayama Shunzo
Published: July 2006

Thermodynamic equilibrium constants for the ion-association in aqueous solutions of magnesium and nickel sulfates were determined by electrical conductivity measurements at various temperatures between 0°C and 45°C. The standard Gibbs energy and the enthalpy and entropy for the reaction M2++SO42−\ightleftharpoonsM2+·SO42− (M: Mg or Ni) were then calculated from the temperature-dependence of the ion-association constants. The values obtained are as follows: ΔG°298=−2.91 kcal mol−1, ΔH°=2.04 kcal mol−1, and ΔS°298=16.6 cal deg−1 mol−1 for Mg2·SO42−; and ΔG°298=−3.10 kcal mol−1, ΔH°=1.27 kcal mol−1, and ΔS°298=14.7 cal deg−1 mol−1 for Ni2+·SO42−.
Orbital Symmetry Control in the Interaction of Three Systems
Authors: Fujimoto Hiroshi , Kato Shigeki , Yamabe Shinichi , Fukui Kenichi
Published: July 2006

Some perturbation equations for calculating the interaction energy of three independent systems have been derived in the frame of the simple Hückel MO approximation. The results of the numerical calculation of some typical interactions of three conjugated systems are presented in order to show the effect of the orbital symmerty upon the interaction energy. The role of the d orbitals of transition-metal catalysis olefin metathesis is examined.
Kinetics of Oxygen Exchange between Selenate Ions and Water
Authors: Okumura Akiko , Okazaki Nobukazu
Published: July 2006

The rate of oxygen exchange between selenate ions and solvent water has been measured by using oxygen-18 as a tracer. At 30°C in the concentration range of [H2SeO4]=0.57–1.5 M, and at 80°C in the region of pH=1.0–2.3, the rate may be expressed as R=k1[H+][HSeO4−]. The values of the energy and entropy of activation are 23.1 kcal/mol and −5.0 e.u.(80°C) at pH=1.12, and 21.8 kcal/mol and −9.9 e.u.(30°C) at [H2SeO4]=1.64 M. An A–2 mechanism has been suggested for this path. Above ca 1.5 M H2SeO4, an additional rate term proportional to [H2SeO4]2 comes into play.
14N Nuclear Quadrupole Resonances of 2-Aminopyrimidine
Authors: Negita Hisao , Shibata Kaoru , Kubo Tsuneo
Published: July 2006

Four nuclear quadrupole resonance (NQR) lines due to 14N nuclei of the ring nitrogens in 2-aminopyrimidine were paired for the powder sample by use of a frequency-modulated spectrometer and a Helmholtz coil for the Zeeman field (H). NQR parameters e2Qq=3707.2 kHz and η=0.0646 were obtained for one nitrogen, and e2Qq=3759.6 kHz and η=0.0329 for the other. Moreover, the frequency of the lower line of a pair of lines for the amino nitrogen was predicted from the shift of the higher line subjected to the Zeeman field in a single crystal. The region around the expected position was carefully swept and a very weak line was found at 2357.8 kHz. Thus e2Qq=3428.0 kHz and η=0.2488 were deduced for the amino nitrogen. The quadrupole coupling constant for the amino nitrogen in 2-aminopyrimidine was smaller than that for the amino nitrogen in 2-aminopyridine. The asymmetry parameter for the amino nitrogen in 2-aminopyrimidine was smaller than that for the amino nitrogen in 2-aminopyridine and roughly equal to that for the amino nitrogen in aniline.
The Adiabatic Compressibility of Nonelectrolyte Aqueous Solutions in Relation to the Structures of Water and Solutions
Authors: Endo Harumi
Published: July 2006

The sound velocity (V) and density of aqueous solutions of urea, dimethylurea, thiourea, acetamide, acetone, and dimethylformamide have been measured, and the adiabatic compressibility (β) has been calculated at various concentrations (μ: mole fraction). The β-μ curves and V-μ curves at various temperatures have a common intersection at the fixed concentrations of μcβ and μcV respectively. At these concentrations, the compressibility (βc) and the sound velocity (Vc) of a solution are independent of the temperature over a certain range. When βc is plotted against the mole ratio, rcβ=(water)/(solute) at μcβ, the plots for acetyl-derivatives fall on one straight line, and those for urea-derivatives, on another line. In the cases of acetone and ethanol, the rcβ values of these solutes coincide with the number of water molecules constituting the framework of the solid clathrate hydrate. Also, for the other aqueous solutions, it may be reasonable to conclude that the rcβ value corresponds to the number of water molecules constituting some other type of liquid-clathrate hydrate characteristic of each solute.
Structure of Ethylene Oxide Oligomer Complexes. IV. Infrared Study of CH3O(CH2CH2O)mCH3–HgCl2 Complexes
Authors: Iwamoto Reikichi
Published: July 2006

Infrared spectra of CH3O(CH2CH2O)mCH3 (m=1–4) in their crystalline complexes with HgCl2 have been measured. There is no significant regular variation of band frequencies depending upon m. Molecular conformations of the compounds in the complexes have been concluded to be CH3–O\undersetT–CH2\undersetG–CH2\undersetT–O\undersetT–CH2\underset\barG–CH2\undersetT–O–CH3 for m=2 and CH3–O\undersetT–CH2\undersetG–CH2\undersetT–O\undersetT–CH2\underset\barG–CH2\undersetT–O\undersetT–CH2\undersetG–CH2\undersetT–O–CH3 for m=3 from molecular structures for m=1 and 4.
Magnetic Properties of Some Iminoxyl Polyradicals. V. EPR Studies of the TEMPAD Biradical
Authors: Nakajima Akira
Published: July 2006

The EPR of pure and diluted crystals of bis(2,2,6,6-tetramethylpiperidine-4)azine-1,1′-dioxyl (the TEMPAD biradical) was studied. From the spectra of the diluted cyrstal, the intra- and inter-molecular dipole-dipole interactions were identified. The crystal-field parameters of the intra-molecular coupling determined for the EPR spectra were: |D|⁄hc\simeq0.00477 cm−1 and |E|⁄hc\simeq0.00032 cm−1 and two kinds of principal axes were found. As the z-axis of the intra-molecular dipole-dipole coupling is in the direction connecting two N–O bonds in a molecule, the TEMPAD molecules in a unit cell may be said to occupy two different sites. The crystal-field parameters of the inter-molecular dipole-dipole coupling were determined to be: |D′|⁄hc∼0.012 cm−1 and |E′|⁄hc∼0.003 cm−1 and the z-axis of the tensor was in the direction of the a-axis. The assumed molecular-stack model could account for the aforementioned results. The EPR spectra of the pure TEMPAD biradical are one symmetrical Lorentzian line in all the directions; the angular dependence of the peak-to-peak linewidths was explained by means of the term of the inter-molecular dipole-dipole interaction obtained from the spectra of the diluted crystal using the three-dimensional Anderson-Weiss formula. The exchange parameter for the best-fit curve was of the order of magnitude of the weak exchange interaction estimated roughly from the small Weiss constant appearing in the paramagnetic susceptibility of the diluted crystals.
The Salting-out Adsorption of Isomeric Butyl Alcohols by Macroreticular Resin
Authors: Hishinuma Kie , \={O}ki Hideo , Kurokawa Y\={o}ichi , Yui Norio
Published: July 2006

The salting-out adsorption of isomeric butyl alcohols on Amberlite (200) type designated as the macroreticular ion-exchange resin (MR type) was studied. On the basis of the difference in the salting-out effect of isomers, the separation of the isomer mixture in a dilute aqueous solution was attempted by using an aqueous ammonium sulfate solution as an eluent and the MR resin as a stationary phase. It seems that MR resin as the stationary phase is inadequate for the salting-out chromatography of isomeric butyl alcohols.
Formation of Uranium Nitride by the Reaction of Uranium Hydride with Nitrogen and Ammonia
Authors: Tagawa Hiroaki
Published: July 2006

The hydrogenation of uranium metal and the nitrogenation of uranium and its hydride with either nitrogen or ammonia have been studied using thermogravimetry. The reactions were examined at different pressures of hydrogen, nitrogen, and ammonia. The reaction of uranium with hydrogen takes place at 200°C and proceeds quickly above 210°C. The conversion curve depends greatly on the hydrogen pressure. In the reaction of the hydride with nitrogen, the weight gain occurs at about 160°C and becomes fast above 240°C. The reaction is shown to proceed in two steps: the formation of the mononitride and that of the sesquinitride. The reaction between uranium hydride and ammonia begins at 150°C and becomes rapid above 300°C. The reaction proceeds monotonously, and no step is observed. The nitrogenation behavior of uranium hydride with ammonia is found to be quite different from that in reaction with nitrogen.
The Determination of Beryllium in Several Alloys by Means of Atomic Absorption Spectrophotometry
Authors: Nakahara Taketoshi , Munemori Makoto , Musha Sôichirô
Published: July 2006

The atomic absorption spectrophotometric determination of beryllium in aqueous solutions and the effect of some water-miscible organic solvents were studied in a nitrous oxide-acetylene flame, using a Perkin-Elmer Model 303 atomic absorption spectrophotometer. The beryllium atomic absorptions were measured at the 234.9-nm resonance line of beryllium. The sensitivity for beryllium was 0.03 ppm for a 1% absorption. With the exception of palladium and silicon, none of the elements interfered with the determination of beryllium. Phosphoric acid caused an enhancement, while hydrochloric and nitric acids had a slight depressing effect. Furthermore, there seems to be a tendency for organic solvents with a higher ratio of the number of carbon atoms to that of oxygen atoms to cause greater enhancements in beryllium absorption, though there are a good number of exceptions. The atomic absorption method was applied to the determination of beryllium in several aluminum-, copper-, and magnesium-base alloys, with satisfactory results.
Effects of Pressure on the Chemical Properties of Solid Surface. VI. The Surface Acidity of the Compressed Zinc Sulfate
Authors: Kawakami Takeshi , Usui Akira , Ogino Yoshisada
Published: July 2006

In order to clarify the mechanism of the acidity change due to compression, zinc sulfate was compressed under various pressures, ranging from 0 to 7000 kg/cm2, and the surface acidity was measured and compared with the data of the structural change in the sample. According to the experimental results, the surface acidity varied on compression. At lower compacting pressures (P∼2500 kg/cm2), the content of weak acid (H0=1.5–3.3) was high and that of the strong acid was poor. These facts were explained by the higher content of anion-water, or heptahydrate, in the sample. In the pressure region of P=2500<5500 kg/cm2, the acidity-pressure curve showed a maximum at 4500 kg/cm2. Further, in this pressure range, the acidity-pressure curve paralleled well the respective curves of the X-ray peak width of hexahydrate pressure, the relative intensity of the IR v1(SO42−)-pressure, and the half width of the IR v3(SO42−)-pressure. It was considered that the acidity change in this pressure range is caused by the change in the content of the distorted structural unit of hexahydrate in the sample. In the highest pressure range, the content of weak acid was found to increase, whereas the content of strong acid was found to decrease. These results were discussed by considering the increased inclusion of tetrahydrate in the sample.
A Study of the Catalytic Partial Oxidation of Hydrocarbons. XVI. The Effect of the Bi2O3 Content in the MoO3-Bi2O3-P2O5 Catalysts on the Oxidation of Various Olefins, Acids, and Aldehydes
Authors: Ai Mamoru , Suzuki Sadao
Published: July 2006

The vapor-phase oxidation of various kinds of olefins, acids, aldehydes, etc. was carried out in a flow system over a series of MoO3–Bi2O3–P2O5 catalysts with different Bi/Mo ratios (P/Mo=0.2 atomic ratio) under fixed reaction conditions, in order to elucidate how the oxidation of these compounds is affected by the Bi2O3 content in the catalysts. The oxidation activity for these compounds varies in different individual manners as the Bi2O3 content increases. The results were interpreted successfully on the basis of the acid-base nature of the reactant and the catalyst. Then, the relationship between the character of the partial oxidations and the nature of the catalysts was discussed.
The Condensation Reactions of 5-Azidotropolone Derivatives with Active Methylene Compounds
Authors: Horino Hiroshi , Toda Takashi
Published: July 2006

The reactions of 5-azidotropolone (I), its methyl ether (II), and tosylate (XIII) with active methylene compounds were investigated. Several tropolones and azulenes which possess the 1,2,3-triazole ring as a substituent were obtained. The order of reactivities in these reactions were found to be: tropolone tosyl groups>azido groups>tropolone methyl ether groups. The direction of the addition of the azido groups to active methylene compounds was also clarified.
The Reaction of O,O′-Diethyl α-Lithiomethylphosphonate with Organic Dihalides
Authors: Oshima Koichiro , Shirafuji Tamio , Yamamoto Hisashi , Nozaki Hitosi
Published: July 2006

The reactions of the α-lithio derivative of diethyl methylphosphonate with various organic halides are described. The half-reduction of gem-dihalocyclopropanes has been achieved with this reagent. The same reagent gives bibenzyl and tetraphenylethane from benzyl bromide and benzhydryl chloride respectively. The deprotonation-metallation process is observed in the reactions of cinnamyl chloride and of trans-β-bromostyrene, in which 3-chloro-1,6-diphenyl-1,5-hexadiene and 1,4-diphenyl-3-buten-1-yne are produced respectively.
Derivatives of Cyclic Disulfides. II. Alkaline Hydrolysis of 1,2-Dithiaacenaphthene S-Oxide
Authors: Tamagaki Seizo , Hirota Hiroo , Oae Shigeru
Published: July 2006

The alkaline hydrolysis of 1,2-Dithiaacenaphthene S-oxide has been investigated kinetically, its reactivity being compared with that of its open-chain analog, phenyl benzenethiolsulflnate. The rate was found to be of first order with respect to both hydroxide and the ester. 1,2-Dithiaacenaphthene S-oxide was found to be hydrolyzed 103 times more slowly than the open-chain analog in an alkaline medium. The reduced reactivity was interpreted on the basis of structural rigidity.
New Agents for t-Butyloxycarbonylation and p-Methoxybenzyloxycarbonylation of Amino Acids
Authors: Nagasawa Takeshi , Kuroiwa Katsumasa , Narita Kouichi , Isowa Yoshikazu
Published: July 2006

A new method for the preparation of t-butyloxycarbonyl amino acids and p-methoxybenzyloxycarbonyl amino acids has been devised. The former was obtained in satisfactory yields from amino acids and t-butyl S-4,6-dimethylpyrimid-2-ylthiocarbonate prepared from t-butyl alcohol and (4,6-dimethylpyrimid-2-ylthio)corbonyl chloride in dry pyridine, and the latter was also obtained from amino acids and p-methoxybenzyl S-4,6-dimethylpyrimid-2-ylthiocarbonate from p-methoxybenzyl alcohol and (S-4,6-dimethylpyrimid-2-ylthio)carbonyl chloride. These t-butyloxycarbonylation and p-methoxybenzyloxycarbonylation of amino acids are more convenient than the usual methods.
Effects of Pressure on the Chemical Properties of Solid Surfaces. VII. Surface Basicities of Some Compressed Carbonates and Related Compounds
Authors: Baba Shoe , Ogino Yoshisada
Published: July 2006

In order to investigate the effect of the compacting pressure on the surface basicities of solids, experiments were carried out by employing various carbonates, hydroxides, and oxides of alkali metals and alkaline earth metals as samples. That is, compacting pressures ranging from 0 to 15000 kg/cm2 were applied to these samples, and the changes in the surface basicities were observed using an indicator method. It was observed that the surface basicities of various solid vary on compression. Further, the respective basicity change in cadmium carbonate, calcite, and aragonite could be explained by the change in the surface area of each of these samples. On the other hand, the basicity changes of both strontium carbonate and barium carbonate could be explained thus only with difficulty. From the results of the X-ray-diffraction study and the electron-diffraction study, the changes in the crystal structures of these samples were suspected of causing the basicity changes due to compressions. According to the results of infrared spectroscopic studies, changes in the symmetry around carbonate ions in the sample crystals were considered to be the cause of the basicity changes in strontium cabonate and barium carbonate.
Total Syntheses of Antimycin A3 and Its Diastereomer
Authors: Kinoshita Mitsuhiro , Aburaki Shinpei , Wada Masao , Umezawa Sumio
Published: July 2006

Natural antimycin A3 (1A) and its diastereomer (1B) were synthesized. By the syntheses, the correlations between configurations of the enantiomeric 2-butyl-4-hydroxy-3-isovaleryloxypentanoic acids present in the dilactone moieties of 1A and 1B, and those of natural (+)blastmycinone (+)7a and its enantiomer (−)7a were confirmed. The absolute configuration of 1B was also determined.
Adsorption of Organic Polymers on Platinum Electrode
Authors: Ohsaka Tetsuya , Abe Yasuyuki , Yoshida Tadashi
Published: July 2006

The adsorption behavior of polyvinylpyrrolidone (PVP), polyethyleneglycol (PEG), and alkylphenoxy polyethoxy ethanols (Triton X) on a smooth platinum electrode was investigated by observation of the inhibition effect on the electrosorption of hydrogen and oxygen in the potential range between hydrogen and oxygen evolution. The adsorption of PVP, PEG, and Triton X on platinum always took place within the potential range from −0.20 to 1.25 V vs. SCE, the inhibition effect on the electrosorption of hydrogen and oxygen being distinctly shown. The order of inhibition of these adsorbates was Triton X>PVP>PEG. The inhibition effect became larger in most cases with decreasing mean molecular weight of adsorbate. In contrast to the case with a mercury, the adsorbates were oxidized or reduced on the platinum electrode in the adsorption range, the anodic peak due to oxidation being distinctly revealed in the case of PEG.
Ultraviolet Spectra of Hydrazide Solutions and Their Hydrolysis. I. Hydrolysis of Formhydrazide in Acid Solutions
Authors: Mashima Mitsuo , Ikeda Fujiko
Published: July 2006

The protonation constant 1.99 of formhydrazide (pKBH+) has been obtained from measurements of its ultraviolet absorption in dilute sulfuric acid. From the absorption in concentrated sulphuric and perchloric acids, the apparent first-order rate constants of acid-catalyzed hydrolysis have been determined. The reaction mechanism of rate-determining steps has been proposed by means of the plots of Zucker-Hammett and Bunnett.
Ultraviolet Spectra of Hydrazide Solutions and Their Hydrolysis. II. Hydrolysis of Formhydrazide in Alkaline Solutions
Authors: Mashima Mitsuo , Ikeda Fujiko
Published: July 2006

The aparent first-order rate constants of the base catalyzed hydrolysis of formhydrazide have been determined by ultraviolet absorption measurements. Three cases of hydrolysis applicable to three different ranges of NaOH concentrations were recognized. The activation entropies have been calculated from the change of rate constant with temperature. The effects of solvent basicity and temperature on the absorption spectra have also been studied.
The Crystal and Molecular Structure of Piperazinium Terephthalate, (H2NC4H8NH2)2+(O2C·C6H4·CO2)2−
Authors: Kashino Setsuo , Sasaki Minoru , Haisa Masao
Published: July 2006

Piperazinium terephthalate has been prepared and examined by X-ray analysis. The compound crystallizes in the monoclinic space group P21⁄c with two formula units in a unit cell. The cell dimensions are: a=9.45, b=8.30, c=8.33 Å, and β=117.3°. The structure was determined by the Patterson method from the data collected with CuKα radiation on Weissenberg photographs, and refined by the block-diagonal least-squares method with anisotropic temperature factors for non-hydrogen atoms and fixed isotropic ones for hydrogen atoms. The final R value is 0.108 for 941 non-zero reflections. Acid and base moieties occupy the positions of center of symmetry in the cell. Two N+−H…O− hydrogen bonds (2.612 and 2.737 Å) link a nitrogen atom of piperazine with two carboxyl oxygens of the acids related by c glide plane to form a three-dimensional hydrogen bond network, in which each oxygen atom accepts one hydrogen bond. The coordination around the nitrogen atom is nearly tetrahedral. The piperazine ring takes a chair form. The twisting angle between the carboxyl group and the benzene ring plane is 17.3°.
Molecular Structure of Nortricyclene Studied by Gas Electron Diffraction
Authors: Bohn Robert K , Mizuno Kazumi , Fukuyama Tsutomu , Kuchitsu Kozo
Published: July 2006

The molecular structure of nortricyclene (tricyclo[2.2.1.02,6]heptane) has been studied by gas phase electron diffraction. The average values of the bond distances and their limits of error are: rg(C–C)=1.532±0.003 Å and rg(C–H)=1.114±0.011 Å. It is further shown that rg(C3–C4)=1.554±0.013 Å, rg(C1–C2)+rg(C2–C3)=3.042±0.010 Å, and ∠C1–C7–C4=96.9±0.5°.
Molecular Vibrations and Force Fields of Alkyl Sulfides. VI. Methyl Ethyl Sulfide and Its Deuterated Compounds, and Diethyl Sulfide
Authors: Ohsaku Masaru , Shiro Yuji , Murata Hiromu
Published: July 2006

Deuterated methyl ethyl sulfides, CD3SCH2CH3 and CH3SCD2CD3, were prepared, and their infrared spectra were recorded in the gaseous, liquid, and solid states. The normal coordinates of methyl ethyl sulfide, its deuterated analogues, and diethyl sulfide have been treated by the use of a modified Urey-Bradley potential field. The conformational analyses of these sulfides were made by the aid of the calculations. In the gaseous and liquid states, two forms (T and G) have been confirmed to exist for CH3SCH2CH3, and three forms (TT, TG, and GG), for CH3CH2SCH2CH3. In the solid state, CH3SCH2CH3 or CH3CH2SCH2CH3 exists in one form: T or TT. The observed infrared frequencies were compared with the calculated frequencies and were fully assigned.
Ionic Mobility of Some Inorganic Ions in Mixed Solvents from Electromigration on Paper
Authors: Lahiri M M , Seal B K , Mukherjee S K
Published: July 2006

Measurements of ionic mobilities of a number of cations and anions in nonaqueous and mixed solvents were made from electromigration on filter paper, and the apparent advantages of the ionophoretic method over other modern techniques have been explained. The values so obtained have been corrected for (a) electroosmotic and (b) tortuosity (i.e., ‘added migration path length’) effects, in order to compare them with those in free solution. Considering the combined effect of dielectric constant and viscosity the ionic mobilities obtained by the electrophoretic method are considered to be of correct order of magnitude. The ionic mobilities at constant dielectric constant when plotted against reciprocal of viscosity show a slight deviation from linearity.
Transmission of Substituent Effects through Oxygen and Sulfur Atoms. III. The Ionization Equilibrium Constants of Ring-substituted cis-β-Phenoxyacrylic Acids
Authors: Kajimoto Okitsugu , Kobayashi Masaru , Fueno Takayuki
Published: July 2006

cis-β-Phenoxyacrylic acid and several of its ring-substituted derivatives were prepared, and their ionization constants were determined in 50% ethanol–water at 25 °C. The Hammett ρ value for the ionization of these acids, 0.439, is smaller than that reported for cis-β-phenylthioacrylic acids, 0.531. The greater efficiency of the sulfur atom in transmitting the substituent effects is explainable in terms of the “through-conjugation” of the sulfur atom in the thioacrylate anions formed.