bluuebunny/crossref_metadata_2025 huggingface dataset:
Far-infrared Absorption of Non-dipolar Liquid Mixtures
Authors: Fujiwara Kenji , Ikawa Shun-ichi , Kimura Masao
Published: July 2006

Far-infrared absorptions of some non-dipolar liquid mixtures have been observed. The changes of the intensities with mixing ratio were examined on the basis of a formula derived for the difference between absorption intensities before and after mixing, to get information about the mixing state.
Kinetic Studies of the Proton-transfer of the Bivalent Anions of ortho-Hydroxy Azo Compounds in Dioxane–Water Media
Authors: Yoshida Noboru , Fujimoto Masatoshi
Published: July 2006

Kinetics of the proton-transfer reactions in dioxane-water media between hydroxide ion and the bivalent anions of 4-(2,4-dihydroxyphenylazo)benzenesulfonic acid (TPO) and 7-hydroxy-8-phenylazo-1,3-naphthalenedisulfonic acid (HPN) were studied by means of the temperature-jump method. For the change in the mole fraction of dioxane from 0 to 0.174, the acid-dissociation constant, Kac(s), was found to decrease from 1.07×10−11 to 5.25×10−14 mol dm−3 for HPN and from 1.32×10−12 to 7.08×10−15 mol dm−3 for TPO.
X-Ray Diffraction Studies on the Structures of Diammine- and Aquasilver(I) Complexes in Aqueous Solution
Authors: Maeda Masunobu , Maegawa Yoshiteru , Yamaguchi Toshio , Ohtaki Hitoshi
Published: July 2006

X-Ray diffraction studies were carried out for aqueous diamminesilver(I) nitrate, silver(I) perchlorate and nitrate solutions. The radial distribution curve of the diamminesilver(I) nitrate solution showed that the length of the Ag–NH3 bond is (2.22±0.02) Å. In the aqueous silver(I) perchlorate solution, a silver(I) ion is combined with two water molecules at a distance of (2.41±0.02) Å, the result being in good agreement with that obtained for the nitrate solution.
Enrichment of a Trace Amount of Manganese by the Mixed Resin Prepared from Finely Divided Anion and Cation Exchangers in the Presence of 4-(2-Pyridylazo)resorcinol
Authors: Abe Masutaro , Takei Noriko , Ohzeki Kunio , Kambara Tomihito
Published: July 2006

The enrichment of a trace amount of manganese(II) from sample water was carried out by the combined use of a mixture of finely divided cation and anion exchangers and 4-(2-pyridylazo)resorcinol (PAR). Manganese–PAR complex was effectively collected onto the mixed resin by batch method in the pH range 9.1–10.2. The manganese on the mixed resin was eluted into hydrochloric acid solution, extracted with 4-benzoyl-3-methyl-1 -phenyl-2-pyrazolin-5-one (BMPP) into MIBK and determined by atomic absorption spectrometry. The recovery of 3 μg of manganese from the synthetic sample solution (100–500 ml) was in the range 95–97%.
ortho-Disubstituted F-Benzenes. II. One-pot Syntheses of (F-Benzo)heterocyclic Compounds
Authors: Inukai Yoshinari , Sonoda Takaaki , Kobayashi Hiroshi
Published: July 2006

Convenient one-pot methods of converting F-benzene into substituted (F-benzo)furans, (F-benz)oxazole, -imidazolines, and -thiazoline are described. Ambident nucleophiles are generated in situ from ketone, amide, urea, thiourea, and their derivatives in the presence of sodium hydride. Enolate-anion nucleophiles are also generated in situ from silyl enol ethers in the presence of potassium fluoride in anhydrous DMF.
Induced Circular Dichroism of β-Cyclodextrin Complexes with Substituted Benzenes
Authors: Shimizu Hiroshi , Kaito Akira , Hatano Masahiro
Published: July 2006

The induced circular dichroism (ICD) of β-Cyclodextrin(β-CDx)-substituted benzene complexes was investigated. We observed the ICD on the absorption bands of achiral substituted benzene molecules, which is considered to be induced by the dissymmetric field of the chiral β-CDx host molecule. The electronic transitions which are polarized along the long axis of the substituted benzenes showed positive ICD, while the sings of the ICD of short-axis polarized transitions are negative. The rotational strengths of these inclusion complexes were calculated by the Kirkwood-Tinoco expression. From the comparison between the experimental and calculated results, it is concluded that these β-CDx complexes favor the axial inclusion in which the long axis of the substituted benzenes is parallel to the axis of the β-CDx cavity.
Simple and Practical Routes to 4,5-Benzocycloheptenone. Ring Enlargement of 3,4-Dihydro-2-ethoxynaphthalene and 2-Alkoxynaphthalenes with Dichlorocarbene
Authors: Uyehara Tadao , Ichida Akio , Funamizu Makoto , Nanbu Hirofumi , Kitahara Yoshio
Published: July 2006

An addition of dichlorocarbene generated by a phase-transfer reaction, to 3,4-dihydro-2-ethoxynaphthalene gave 7,7-dichloro-6-ethoxy-2,3-benzobicyclo[4.1.0]hept-2-ene, from which 4,5-benzocycloheptenone was derived in preparative yield. 2-Methoxy- and 2-ethoxynaphthalene were converted into 2-chloro-4,5-benzotropone in 33 and 66% yield, respectively, by treatment with large excess of ethyl trichloroacetate arid sodium methoxide.
Studies on the Syntheses of Sesquiterpene Lactones. III. Improved Synthesis of Vulgarin
Authors: Ando Masayoshi , Tajima Kiyoshi , Takase Kahei
Published: July 2006

An improved synthesis of vulgarin is described. Epoxidation of 1-oxo-5αH,6β,11βH-eudesm-3-en-6,13-olide and successive treatment of the resulting epoxide with silica gel gave vulgarin. Oxidation of 1-oxo-5αH,6β,11βH-eudesm-3-en-6,13-olide with air or oxygen gas gave 4α-hydroperoxy-1-oxo-5αH,6β,11βH-eudesm-2-en-6,13-olide and 4β-hydroperoxy-1-oxo-5αH,6β,11βH-eudesm-2-en-6,13-olide, which were transformed into vulgarin and C4-epivulgarin, respectively.
The Base-catalyzed Tautomerization of Acetylacetone in Organic Solvents. The Correlation of the Catalytic Coefficient with the Partition Coefficient
Authors: Watarai Hitoshi , Suzuki Nobuo
Published: July 2006

The keto-enol tautomerization rate of acetylacetone catalyzed by triethylamine or tributylamine was observed in eight organic solvents, and the catalytic coefficient for each process of the ketonization and enolization was obtained. A remarkable solvent effect on the catalysis was discussed following the linear free-energy relationship between the catalytic coefficient and the liquid-liquid partition coefficients of the keto and enol forms. It was concluded that, in the homogeneous base-catalysis, the solvent affects the free-energy change of the transition state more greatly than those of the keto and enol forms. On the contrary, in the heterogeneous catalysis by the silica surface, the free-energy change of the keto and enol forms was suggested to be the main factor governing the kinetic solvent effect.
NMR Studies on Zerovalent Metal π-Complexes of Dibenzylideneacetone. II. Structure and Pt–H Coupling in the Binuclear Platinum Complex
Authors: Tanaka Hisao , Kawazura Hiroshi
Published: July 2006

The NMR analysis on the olefinic protons of the binuclear complex Pt2[(C6H5CH=CH)2CO]3 was conducted on the deuteriated compounds Pt2[(C6D5CH=CH)2CO]3, Pt2[(C6D5CD=CH)2CO]3, and Pt2[(C6D5CH=CD)2CO]3. Examination of the various 1H NMR parameters revealed the individual characteristics of the six coordinated olefins of three dibenzylideneacetone ligands with respect to the metal-olefin bonding and coordination geometry. The three ligands which triply bridge the two Pt atoms are composed of one s-cis,cis ligand which is distant from the Pt atoms and of two s-cis,trans ligands which are close to the Pt atoms. Asymmetry in the coordination, which is caused by the gliding of the olefinic double bond to the metal atom, becomes greater as the olefinic moiety approaches the metal atom more closely. The major transmission route of the Pt–olefinic proton coupling is attributable to metal to olefin π-back bonding.
Trimethylenediamine Complexes. VII. Optically Active Mixed-Ligand Cobalt(III) and Chromium(III) Complexes Containing Trimethylenediamine and the Acetylacetonate Anion
Authors: Nakano Mamoru , Kawaguchi Shinichi , Kawaguchi Hiroshi
Published: July 2006

The [M(acac)(tn)2]2+ and [M(acac)2(tn)]+ complexes (M=Co and Cr) have been prepared and resolved by (R,R)-tartratoarsenate(III) and hydrogen-(R,R)-di-O-benzoyltartrate, respectively. On the basis of the CD-spectral studies in comparison with the corresponding ethylenediamine complexes, the absolute configurations of (+)589-[Co(acac)(tn)2]2+, (−)589-[Co(acac)2(tn)]+,(+)589-[Cr(acac)(tn)2]2+, and (−)589-[Cr(acac)2(tn)]+ were all assigned to Λ. Electronic spectra of these complexes and proton NMR spectra of the cobalt(III) complexes are also reported.
11B-NMR Study of the Complex Formation of Borate with Catechol and l-Dopa
Authors: Yoshino Kazuo , Kotaka Masahiro , Okamoto Makoto , Kakihana Hidetake
Published: July 2006

In the solution of catechol and borax at pH 11, the equilibria between catechol and the monomeric borate anion to form the 1 : 1 and 2 : 1 (catechol: boron) anionic complexes have been demonstrated by the existence of 11B-NMR signals for the two complexes and the monomeric borate anion. In the solution of l-dopa and borax at pH 11, however, the signal for the 2 : 1 anionic complex was not observed, though it was observed below pH 7. By the 11B-NMR spectra at pH 6.5, the complex formation constants, logK1 and logK2, have been estimated as 3.9 and 4.4 for catechol, and as 4.3 and 5.0 for l-dopa, respectively.
p-Styrenesulfinic Acid and Its Polymer as Reactants
Authors: Kamogawa Hiroyoshi , Inoue Hideaki , Fukuyama Hiromoto , Nanasawa Masato
Published: July 2006

The free-radical aqueous polymerizations of p-styrenesulfinates (Na, K, NH4, NHEt3-salts) provided watersoluble polymers with high molecular weights at low conversions. The polymers contained 62–84% of the sulfinate unit and indicated half-oxidation potentials ranging from 340 to 415 mV. The nucleophilic reactions of the sodium polysulfinate [poly(sulfinic acid)] prepared from cross-linked polystyrene are highly dependent upon the swelling nature of the solvent. The reactions consisting of (A) simple displacements with activated halomethyl groups, (B) reductive additions to quinonoid compounds such as TCNQ and alizarin, and (C) displacements of the activated aromatic nitro groups, e.g., of 2,4,7-trinitrofluorenone have been investigated and the results compared with those of p-toluene and p-styrenesulfinates. The effect of the solvent on the reaction rate is in the order: DMSO>DMF>HMPA.
The Low-Energy π,π* S-S Absorption Spectra of 1,4-Dimethyl-and 1,4-Dichloroanthraquinones
Authors: Kuboyama Akira
Published: July 2006

The very broad absorption band of 1,4-dichloroanthraquinone, which corresponds to the allowed 1B2uπ,π* band of anthraquinone (AQ), is shown to consist of two π,π* bands with comparable intensities. The band which corresponds to the 1Ag forbidden band of AQ is at longer wavelengths than the band corresponding to the 1B2u band of AQ. MO calculations were made, and MCD spectra and 77 K absorption spectra were measured. The very broad absorption band of 1,4-dimethyl-AQ can probably be similarly interpreted. The strong visible π,π* bands of 1,4- and 1,5-disubstituted AQ’s are shown to arise from the 1Ag and 1B2u bands of AQ, respectively.
A Study of the Spin-Lattice Relaxation Time, T1, of Coal-derived Oil
Authors: Yoshida Tadashi , Maekawa Yosuke , Uchino Hiroyuki , Yokoyama Susumu
Published: July 2006

The spin-lattice relaxation time, T1, of carbons was measured for various types of carbons in ring-type fractions separated from coal-derived oil. The T1 for most carbons in the coal-derived oil was less than 2 s because of the existence of free radicals, while the T1’s of aromatic non-protonated carbons in the monocyclic and bicyclic aromatics fractions were approximately 12–15 s. The effects of a relaxation reagent on the T1 were also discussed.
Synthesis of Some 3-Methylbut-2-enylated 1,3,5-Trihydroxyxanthones
Authors: Gujral Vinod , Gupta S R
Published: July 2006

1,3,5-Trihydroxyxanthen-9-one reacts with 2-methylbut-3-en-2-ol in presence of a catalytic amount of BF3-etherate to yield a mixture of 1,3,5-trihydroxy-2,4-bis-(3-methylbut-2-enyl)xanthen-9-one, in poor yield, identical with natural 8-desoxygartanin along with 1,3,5-trihydroxy-4-(3-methylbut-2-enyl)xanthen-9-one (3), in good yield, and 1,3,5-trihydroxy-2-(3-methylbut-2-enyl)xanthen-9-one (4) in poor yield. Compounds 3 and 4, the probable biogenetic precursors of 6-desoxyisojacareubin and 6-desoxyjacareubin, have been reported to occur in nature as such but were characterised as their dimethyl ethers. Compounds 3 and 4 on oxidative cyclisation with DDQ, gave 6-desoxyisojacareubin and 6-desoxyjacareubin respectively, completely identical with authentic natural samples.
Structural Studies of Commensurate Peierls State of Rb1.67[Pt(C2O4)2]·1.5H2O
Authors: Kobayashi Akiko , Sasaki Yukiyoshi , Kobayashi Hayao
Published: July 2006

X-Ray examination, chemical analyses and electrical conductivity measurements have been conducted on the partially oxidized platinum complex Rb1.67[Pt(C2O4)2]·1.5H2O (RbDOX). The cell constants are a=12.690(10), b=17.108(14), c=11.357(3) Å; α=102.04(4), β=115.17(3), γ=43.58(4)°, and the space group is P\bar1. The planar bis(oxalato)platinate ions stack along the crystallographic b axis and the Pt atoms form a sixfold distorted chain. RbDOX is the first example of a sixfold structure. Three independent Pt–Pt distances are 2.717(3), 2.830(3), and 3.015(3) Å. The Pt–Pt distance of 2.717 Å is the shortest spacing so far observed in partially oxidized platinate salts and shorter than the 2.77 Å interatomic separation in Pt metal itself. The oxalate ligands are staggered (46°, 55°, 80°) with respect to the ligands directly above and below them along the chain. Sixfold modulated superstructure of RbDOX is confirmed as the newly found commensurate Peierls structure based on agreement with the period of the Peierls distorted superlattice determined by the degree of partial oxidation. The calculation of Coulomb energy shows that RbDOX has a crystal lattice in which the interchain Coulomb energies are at a minimum indicating the strong tendency of the anti-phase ordering of the nearest-neighbour Pt chains.
High Resolution Infrared Spectrum of Chlorine Dioxide: The v2 Fundamental Band
Authors: Hamada Yoshiaki , Tsuboi Masamichi
Published: July 2006

Fourier transformed infrared absorption spectrum of gaseous ClO2 has been obtained with the resolution of 0.06 cm−1. The rotational structure of the bending fundamental band (v2=1←0) was analyzed. Rotational constants determined were in good agreement with previous microwave results. The band center was now fixed at 447.675±0.030 cm−1, and five centrifugal distortion constants for the v2=1 state were also newly determined.
Kinetics of the Oxidative Addition Reaction of Iodine to (Dimethyldithiocarbamato)bis(2,4,6-rimethylphenyl isocyanide)rhodium(I)
Authors: Kuwae Ryosho , Tanaka Toshio , Kawakami Katsuhiko
Published: July 2006

The reaction of Rh(dtc)L2 (dtc=S2CN(CH3)2, L=2,4,6-(CH3)3C6H2NC) with an equimolar amount of iodine yields a trans adduct, RhI2(dtc)L2. The rate of this reaction was measured in benzene, employing a stopped flow technique under pseudo-first-order conditions with excess iodine. The result indicates that the reaction proceeds via a charge transfer complex Rh(dtc)L2·I2, which is rearranged in two consecutive zero-order reactions with respect to the I2 concentration; the rearrangement of Rh(dtc)L2·I2 to a cis adduct followed by isomerization to the trans adduct. This mechanism is supported from kinetic data for the reaction of Rh(acac)L2 (acac=CH3COCHCOCH3) with I2. It is also described that RhI(I3)(dtc)L2 and RhI(I3)(acac)L2 were obtained by reactions of Rh(dtc)L2 and Rh(acac)L2 with excess iodine, respectively.
Synthesis and Structure of a Hexa-coordinated Vanadium(IV) Complex Aquaoxo[N-(2-pyridylmethyl)iminodiacetato]vanadium(IV) Dihydrate
Authors: Ooi Shun’ichiro , Nishizawa Masato , Matsumoto Keiji , Kuroya Hisao , Saito Kazuo
Published: July 2006

A new complex, aquaoxo[N-(2-pyridylmethyl)iminodiacetato]vanadium(IV) dihydrate [VO(pmida)(H2O)]·2H2O has been synthesized and its crystal structure determined by the X-ray method. The triclinic crystals obtained from water or aqueous ethanol solution are twinned and contain 2 mol of lattice water. The unit cell contains four formula units and the structure was analyzed on the assumption that the space group is P\bar1. The positional and thermal parameters were refined to R=0.115. The vanadium atom has a distorted octahedral coordination and deviates by 0.39 Å from the equatorial plane, which is composed of two cis carboxylate oxygens, a water molecule and the pyridine nitrogen. Vanadyl oxygen and tertiary nitrogen occupy the axial sites. Absorption spectra indicated that the structure is maintained in an aqueous solution of pH 3.0 to 4.9. This geometrical isomer seems to be formed selectively in an aqueous medium.
The Partial Reduction of Carboxylic Acids to Aldehydes via 3-Acylthiazolidine-2-thiones with Diisobutylaluminum Hydride and with Lithium Tri-t-butoxyaluminum Hydride
Authors: Izawa Toshio , Mukaiyama Teruaki
Published: July 2006

3-Acylthiazolidine-2-thiones, easily prepared from carboxylic acids and readily available thiazolidine-2-thione, were reduced to the corresponding aldehydes either with diisobutylaluminum hydride in toluene at −78–−40 °C in 70–90% yields or with lithium tri-t-butoxyaluminum hydride in tetrahydrofuran at −20-0 °C in 80–90% yields. The present method appears to be applicable to the synthesis of aldehydes from both aromatic and aliphatic derivatives having chloro, bromo, nitro, and noncojugated double bond, except for the reduction of α,β-unsaturated derivatives with lithium tri-t-butoxyaluminum hydride and of cyano derivative with diisobutylaluminum hydride. Completion of the reduction is indicated by disappearance of the original yellow color of the reaction mixture.
Studies on N1-Hydroxy-N1,N2-diarylbenzamidines as Metal Complexing Agents: Extraction-Photometric Determination of Iron(III) as Thiocyanato and Azido Mixed Ligand Complexes with N1-Hydroxy-N1,N2-diphenyl-p-toluamidinel(HDPTA)
Authors: Patel K S , Deb Kanak Kanti , Mishra Rajendra K
Published: July 2006

N 1-Hydroxy-N1,N2-diarylbenzamidines react with iron(III) in presence of thiocyanate and azide forming coloured complexes which are quantitatively extractable in benzene. The extraction of iron(III) as red Fe(III)–L–(SCN−)2 complex is quantitative at 0.1–0.6 M hydrochloric acid concentration, whereas the Fe(III)–L–(N3−)2 complex gets quantitatively extracted into benzene at pH 1.0–2.5. The ternary iron(III)-thiocyanato complex of N1-hydroxy-N1,N2-diphenyl-p-toluamidine(HDPTA) has a fairly large molar absorptivity (1.01×104 1 mol−1 cm−1) and the spectrophotometric method based on this colour reaction is highly selective as almost all common ions including Fe(II) do not interfere. The method employing the formation of ternary iron(III): HDPTA: azide complex is also highly selective.
Oxidation of Ammonia with Lattice Oxygen of Metal Oxides by Pulse Reaction Technique
Authors: Kosaki Yukio , Miyamoto Akira , Murakami Yuichi
Published: July 2006

On V2O5, MoO3, and WO3, lattice oxygen has been found to be the active oxygen species for the catalytic oxidation of NH3, whereas on MnO2, Co3O4, Fe2O3, and NiO, adsorbed oxygen also played a significant role in the reaction. NO has been found to be an intermediate in the reaction of NH3 with lattice oxygen.
Substituent Effects in Heterogeneous Catalysis. V. Steric Hindrance of Bulky AlkyI Substituents in Cyclohexanone Hydrogenation
Authors: Chihara Teiji , Tanaka Kazunori
Published: July 2006

The reactivities of 2-isopropyl- and 2-t-butylcyclohexanone were measured relative to cyclohexanone in both individual and competitive hydrogenation over Ru/Al2O3, Rh/Al2O3, and Pt/Al2O3. The results obtained suggest that alkyl substitution sterically hinders much more significantly the ketone adsorption than the following surface reaction. A molecular model is presented for adsorption of each ketone.
Population Analysis of (R)-Thiazolidine-4-carboxylic Acid
Authors: Kamo Jun , Tanaka Nobuo , Matsuura Yoshiki , Ashida Tamaichi , Kakudo Masao
Published: July 2006

The structure of (R)-thiazolidine-4-carboxylic acid was refined at 111 and 293 K, respectively. Population analysis, which refines the population of the electrons in the molecule, was carried out, the result being compared with that of theoretical calculation.
Phase Transition of SnCl2(H2O)x(D2O)2−x as Studied by High Resolution Heat Capacity Measurement
Authors: Tatsumi Masami , Matsuo Takasuke , Suga Hiroshi , Seki Syûzô
Published: July 2006

The previously published heat capacity data on Sncl2(H2O)x(D2O)2−x (x=2.00, 1.97, 1.75, 1.50, 0.96, 0.50, 0.25, 0.03) were analyzed to derive anomalous contribution due to the phase transitions that occur between 218 and 235 K depending on the isotopic composition. The phase transition is of the first-order for x=2.00, 1.97, and 1.75. The entropy discontinuities at the transitions are (0.149±0.005), (0.152±0.005), and (0.133±0.010) J K−1 mol−1, respectively, out of the total transition entropies of 3.98, 3.90, and 3.89 J K−1 mol−1. The first-order transition does not occur for the other crystals for which the heat capacity anomaly is rounded. Apparent critical exponent α of the heat capacity was calculated for all of the crystals. They are in the range from 0.43 to 0.80 and have the same value below and above the transition temperature for each of the crystals in agreement with the spatial two dimensionality of the crystal structure. No evidence was found for crossing-over to the three dimensional ordering. Change of the transitional behavior with the isotopic composition was discussed in analogy with the liquid-vapor critical phenomenon. An argument based on the crystallographic symmetry of the actual crystal and the corresponding dimer lattice was advanced for this interpretation of the unusual isotope effect.
Stereospecific Synthesis of d-Isothreonine from l-Threonine
Authors: Shimohigashi Yasuyuki , Waki Michinori , Izumiya Nobuo
Published: July 2006

d-Isothreonine, (2R,3S)-3-amino-2-hydroxybutanoic acid (4), was readily prepared by the ammonolysis of optically active 2-bromo-3-hydroxybutanoic acid derived from l-threonine. The configuration of 4 was deduced from the shift of molecular rotation, Cotton effect in ORD curve of 4, and NMR measurement of its oxazolidone derivative.
Modification of Aminocyclitol Antibiotics. 7. Preparation of 5-Epikanamycin B
Authors: Suami Tetsuo , Nakamura Katsumi
Published: July 2006

A configuration of the OH group on C-5 of 2-deoxystreptamine moiety of kanamycin B has been epimerized. 5-Epikanamycin B thus obtained was tested against several microorganisms. The structure of the antibiotic was elucidated by 1H and 13C NMR spectrometry.
Polarity of Free Radicals in Hydrogen Abstraction Reactions
Authors: Shinohara Hiroyuki , Imamura Akira , Masuda Takahiro , Kondo Masaharu
Published: July 2006

The electrophilicity of the CF3 radical in hydrogen abstraction reactions was studied theoretically by the CNDO/2 method. The activation energy for hydrogen abstraction by the CF3 radical from aliphatic hydrocarbons decreases with an increase in the electron density on the hydrogen atom to be abstracted. The origin of the electrophilicity of the CF3 radical can be well understood by the stabilization energy due to delocalization of electrons (SEDE) between the radical and substrate. The electrophilic stabilization energy denned by the SEDE from substrate to the radical governs the relative reactivities of aliphatic hydrocarbons, CH4<CH3CH3<CH3CH2CH3<(CH3)3CH, which corresponds to the order of the increase in the electron density. The results indicate that the radical is an electrophile if the relative reactivities of substrates are governed by the electrophilic stabilization energy, and a nucleophile when the reactivities are governed by the nucleophilic stabilization energy (the SEDE from the radical to substrate). SEDE was calculated for the reactions of the OH and the CH3 radicals with CH4and CH3CN; the results indicated that the OH radical is electrophilic and the CH3 radical nucleophilic. These polarities of radical reagents are discussed in connection with their physicochemical properties such as ionization potentials and electron affinities.
The Solvent Extraction Study of a Dibenzo-18-crown-6 Complex with Silver Picrate
Authors: Takeda Yasuyuki , Takahashi Fujio
Published: July 2006

The extraction constant of the silver ion–dibenzo-18-crown-6 (DB18C6) complex between benzene and water and the complex-formation constant of DB18C6 with silver picrate in benzene were determined at 25 °C. The Ag+–DB18C6 complex is much more extractable than the Ag+–18-crown-6 one. The Ag+–DB18C6 complex is much more stable for benzene than for aqueous solutions.
Adsorptive Mechanism on Activated Carbon in the Liquid Phase. III. The Relationship between the Physical Constants of Organic Compounds and Their Adsorbabilities on Activated Carbon from an Aqueous Solution
Authors: Abe Ikuo , Hayashi Katsumi , Kitagawa Mutsuo , Urahata Toshihiro
Published: July 2006

In order to evaluate the adsorbability for a given activated carbon from a knowledge of the physical properties of the adsorbate, the partition coefficients (α) of 93 organic compounds between the solution and the adsorbed phases at an infinite dilution have been calculated and correlated with the various physical constants. For aliphatic monofunctional compounds, a good linear relationship is obtained between logα and the following physical constants: molecular weight, molar attraction constant, and modified organicity/inorganicity value. This indicates that these physical constants are useful for predicting the adsorbability of aliphatic monofunctional compounds and that a straight line represents the adsorption characteristics of a given activated carbon. The correlation coefficient between the logα value and the physical constants for multifunctional compounds is lower than that for monofunctional compounds. The adsorptive mechanism on activated carbon in an aqueous solution is discussed on the basis of the conclusion obtained in the previous paper.
Synthesis and Electrical Properties of TCNQ Radical Anion Salts with N,N′ Ethylenedi(1,3-dithiolan-2-iminium) Dication and Related Dications
Authors: Yumoto Yoshiji , Nishioka Ryoji , Tanaka Toshio
Published: July 2006

Simple and complex salts of the TCNQ\ewdot radical anion with N,N′-ethylenedi(1,3-dithiolan-2-iminium) dication and related dications, (Remark: Graphics omitted.) (R=H, Me; n=2, 6; m=2, 3, or 4) and (Remark: Graphics omitted.) (m=2, 3) were synthesized. All the salts as compacted samples display semiconducting behaviors in the 77–300 K range. Electrical resistivities of the simple salts are in the range of 1.8×105–9.8×107Ω cm at 25 °C. Electronic absorption spectra and magnetic susceptibilities suggest that the simple salts in the solid state involve (TCNQ)22− dimer. The 1 : 3 complex salt of N,N′-dimethyl-N,N′-ethylenedi(1,3-dithiolan-2-iminium) with TCNQ, (Remark: Graphics omitted.), exhibits a lower electrical resistivity (3.4 Ω cm) than other four complex salts (2.4×10–2.5×103Ω cm). Electronic absorption spectra and magnetic susceptibilities of the both 1: 3 and 1:4 complex salts are interpreted in terms of the interaction between the TCNQ moieties.
The Crystal and Molecular Structure of Epoxyisoacoragermacrone
Authors: Ueda Hideo , Katayama Chuji , Tanaka Jiro
Published: July 2006

The crystal and molecular structure of epoxyisoacoragermacrone, which is an important derivative of acoragermacrone isolated from Acorus calamus L. for the study of the structural organic chemistry and biogenetic reactions, has been determined by the X-ray method. The crystal is orthorhombic, P212121, with lattice parameters a=7.425(2), b=26.604(8), and c=7.150(2) Å. The ten-membered ring is in a boat-chair conformation similar to the highly strained cis, trans-germacradiene system. The methyl groups take the axial and syn arrangement, and are on the β-face of the medium ring.
Preparation of Copper(I)–Phosphine Complexes Having Cu–N Bonds and Their Reactions with Organic Halides
Authors: Yamamoto Takakazu , Ehara Yoshio , Kubota Minoru , Yamamoto Akio
Published: July 2006

Reactions of a methylcopper complex CH3Cu(PPh3)2(diethyl ether)0.5 (PPh3=triphenylphosphine) with active N–H compounds HNR1R2 give the corresponding copper derivatives formulated as R1R2NCu(PPh3)n (n=2 for R1R2N=phthalimido, succinimido, N-phenylacetamido (4), acrylamido, phenylamido, and 2-oxo-1-pyrrolidinyl; n=1 for R1R2N=acetamido). The IR and NMR spectroscopic data of the complexes support the bonding of the R1R2N group to Cu through nitrogen. The reactions of the Cu(I)–N complexes with alkyl and aryl halides (RX) afford the corresponding N-substituted compounds RNR1R2 in high yields.
The Crystal Structure of Bis(2,2′-bipyridine)nitratocopper(II) Nitrate Monohydrate [Cu(NO3)(bpy)2]NO3·H2O
Authors: Nakai Hisayoshi
Published: July 2006

The crystal structure of the title compound has been redetermined from diffractometer data and refined by the least-squares method to R=0.053 for 2448 non-zero reflections. The crystal is triclinic, with a=7.464(3), b=10.002(5), c=15.503(6) Å, α=111.50(5), β=91.43(5), γ=90.47(4)°, space group P\bar1, and Z=2. The copper atom has a square-pyramidal coordination very distorted by the 4 N atoms of the bipyridine ligands and one of the O atoms of the nitrato ligand at the apical position. The disposition of the 4 N atoms at the basal plane is flattened tetrahedral. The Cu atom is displaced by 0.31 Å from the mean plane of the 4 N atoms towards the apical O atom. The Cu–O and the average Cu–N distances are 2.30 and 2.01 Å respectively. In both bipyridine molecules, the two pyridine planes are twisted slightly from each other; the interplanar angle is 2.6° in one bipyridine ligand and 6.0° in the other. The mean planes of the two bipyridine molecules make an angle of 44.6°.
Absolute Rate Constants for the Reactions of O(3P) with Several Molecules
Authors: Sugawara Ko-ichi , Ishikawa Yo-ichi , Sato Shin
Published: July 2006

Absolute rate constants were measured for several reactions of ground-state oxygen atoms at 296±2 K. The pulse-radiolysis of O2, CO, or CO2 in the He diluent was used to produce oxygen atoms, and the atomic concentration was monitored by the resonance absorption. The measurements were made in the pressure range from 50 to 950 Torr (1 Torr \simeq133.3 Pa). The rate constants thus obtained were (2.5±0.3)×10−34 for O+O2+He and (1.0±0.2)×10−35 for O+CO+He in units of cm6 molecule−2 s−1 (1 cm6 molecule−2 s−1\simeq3.626×1035 m6 mol−2 s−1). For simple olefins, the following bimolecular rate constants (k⁄10−12 cm3 molecule−1 s−1) were obtained: Ethylene (1.0±0.2), propene (4.7±0.3), 1-butene (4.7±0.5), trans-2-butene (23±3), cis-2-butene (20±3), 2-methylpropene (17±2), 2-methyl-2-butene (55±5), 1,3-butadiene (20±2), (1 cm3 molecule−1 s−1\simeq6.022×1017 m3 mol−1 s−1). These rate constants were in fair agreement with the literature values.
Kinetic Studies on the N,N-Type Smiles Rearrangement
Authors: Sunamoto Junzo , Kondo Hiroki , Yanase Fumihiro , Okamoto Hiroshi
Published: July 2006

The Smiles rearrangement reaction of Dl-2-aminododecanoic acid N-methyl-p-nitroanilide to Dl-2-(p-nitrophenyl)aminododecanoic acid N-methylamide has been investigated in aqueous alkaline media containing 0–50% (v/v) acetonitrile or ethanol at 25 °C. It was found from the pH-rate profile that the reactive species is the free base form of the substrate. Acetonitrile content in the medium appreciably affected the rate with a maximum at ca. 20% in the acetonitrile content. The cationic CTAB micelles accelerated the rate 4.4-fold at pH 10, while the anionic SDS micelles suppressed the reaction almost completely. These effects of solvent and micelles were qualitatively correlated with the transition state of the reaction. A plausible mechanism for this reaction is the Smiles type rearrangement in which a spiro σ-complex is involved. The activation parameters obtained and suppression of the reaction rate by Cu(II) ion are in line with the proposed reaction mechanism.
Photolysis of Dibenzoyl Peroxide under Direct and Singlet Sensitized Irradiations. Mechanism for the Formation of the Geminate Product
Authors: Kitamura Akihide , Sakuragi Hirochika , Yoshida Masayuki , Tokumaru Katsumi
Published: July 2006

Attempts have been made to elucidate the mechanism for the efficient production of phenyl benzoate, the geminate product, from direct and singlet sensitized irradiations of dibenzoyl peroxide in solution. It is concluded that these irradiations produce a reactive state of the peroxide which can undergo two-bond cleavage of the O–O and C(α)–C(carbonyl) bonds to give a phenyl–benzoyloxy radical pair in a solvent cage, followed by the recombination of the component radicals to give the geminate product or by their diffusion out of the solvent cage to give diffusion products.
The γ-Ray Induced Oxidation of Aromatic Hydrocarbons in Liquid Dinitrogen Oxide
Authors: Karasawa Hidetoshi , Yugeta Rei , Sato Shin
Published: July 2006

The γ-ray induced oxidation of aromatic hydrocarbons has been studied in liquid dinitrogen oxide, mainly at −18°C. Various mixing ratios of dinitrogen oxide and four aromatic hydrocarbons have been examined. The main oxygen-containing products observed were the corresponding phenols and benzyl alcohols. The kinetic analysis showed that ionic species, probably N2O− ions, are the main precursors at low mole fractions of dinitrogen oxide and that oxygen atoms become important with an increase in the mole fraction. 1-Butene was used as a scavenger of oxygen atoms. The following rate constant ratios were obtained for the reactions of oxygen atoms and N2O− ions: k(O+toluene)/k(O+1-butene)=0.02, k(O+toluene)/k(O+benzene)=2.0, and k(N2O−+1-butene)/k(N2O−+toluene)=2.5. The relative rates for the formation of the corresponding phenols and benzyl alcohols through ionic reactions from aromatic hydrocarbons were obtained as follows: benzene, 1.0; toluene, 2.5; p-xylene, 2.2; 1,3,5-trimethylbenzene, 3.1. These values are quite different from the relative rate constants of the reactions of oxygen atoms with these aromatic hydrocarbons.
Calorimetric Study of the Glassy State. XV. Thermodynamic Study of Pinacol Hexahydrate and Pinacol-d2 Hexadeuterate
Authors: Oguni Masaharu , Matsuo Takasuke , Suga Hiroshi , Seki Syûzô
Published: July 2006

The heat capacities of pinacol hexahydrate and its deuterate analogue were measured in the temperature region between 13 and 260 K. A phase transition was found and the temperature of transition was determined to be 192.14 K for the hydrate and 191.17 K for the deuterate, respectively. The enthalpy and entropy of the transition were estimated to be 924 J mol−1 and 5.10 J K−1 mol−1 for the hydrate and 944 J mol−1 and 5.28 J K−1 mol−1 for the deuterate. The transition was interpreted as the order-disorder change of the orientations of the pinacol molecule. Besides the phase transitions, an additional anomaly was found around 150 K for the hydrate and two around 130 K and around 160 K for the deuterate, respectively. All of them are relaxational in their characteristics and interpreted as glass transitions due to freezing of reorientational motions of the water molecule and the pinacol molecule. The transition temperature and the activation enthalpy for the higher glass transition of the deuterate were estimated to be 167.2 K and (34±4) kJ mol−1, respectively.
A Spectrophotometric Study of Tributyl Phosphate Adducts of Three Bis(β-diketonato)copper(II) Complexes in Carbon Tetrachloride
Authors: Sekine Tatsuya , Tosaka Teruyuki
Published: July 2006

Adduct formation equilibria between bis(2-thenoyltrifluoroacetonato)-, bis(trifluoroacetylacetonato)-, and bis(hexafluoroacetylacetonato)copper(II) chelates and tributyl phosphate (TBP) in water-saturated carbon tetrachloride were studied spectrophotometrically at 25 °C. The chelates added one TBP molecule and decreased the absorption, but not very much. The formation constants obtained from the changes in the absorption, given as a function of the TBP concentration, agreed very well with those obtained previously by a solvent-extraction method.
Neutron Diffraction Study of Aqueous Ionic Solutions. II. Aqueous Solutions of Sodium Chloride and Potassium Chloride
Authors: Ohtomo Norio , Arakawa Kiyoshi
Published: July 2006

The structure factors Sm(Q) for aqueous solutions of NaCl and KCl at room temperature have been determined by means of the LINAC-TOF-neutron diffraction method. A revised subtraction method was applied to diffraction data of the solutions. Results obtained for the structure of the nearest hydration shell around ions are as follows, (a) The coordination numbers are 8 for Na+ and 6 for Cl− in the NaCl solution and 8 for K+ and 6 for Cl− in the KCl solution; (b) the average ion-oxygen distances are 2.50±0.10 Å for Na+, 2.70±0.10 Å for K+, and 3.10±0.05 Å for Cl−; (c) around chloride ions water molecules take the configuration to orient the vector which bisects the D–O–D angle on a straight line joining an oxygen atom and the anion. Analysis was performed on the data of LiCl and CsCl solutions.
ESR Study of the Phosphorescent State of Benzo[f]quinoline
Authors: Sekiya Hiroshi , Gondo Yasuhiko , Kanda Yoshiya
Published: July 2006

Electron spin resonance absorption has been observed in a single-crystal solid solution of benzo[f]quinoline in biphenyl under irradiation at 120 K with light from a high-pressure mercury lamp. The fine structure of the resonance spectrum observed at 9.25 GHz can be described by the spin Hamiltonian

H=βH·g·S+D[S_z^2-\frac13S(S+1)]+E(S_x^2-S_y^2)

in which S=1, D=±0.09926(18) cm−1, E=\mp0.04781(6) cm−1, gxx=2.0024(6), gyy=2.0018(4), and gzz=2.0018(4); the z axis is normal to the molecular plane, the x and y axes being the in-plane fine-structure principal axes. The principal x axis deviates by ±4° from the biphenyl long axis and the principal z axis by 7° from the biphenyl out-of-plane axis. The phosphorescence spectra and lifetimes have been measured both at 77 K and at 4.2 K. Marked doublet splittings were observed in the phosphorescence bands at 4.2 K, suggesting a large guest-host interaction.
An ENDOR Study of the Hindered Internal Rotation of the Cyclopropyl Group in the 2,6-Di-t-butyl-4-cyclopropylphenoxyl Radical
Authors: Shimoda Fumio
Published: July 2006

The ESR and ENDOR spectra were observed for the 2,6-di-t-butyl-4-cyclopropylphenoxyl radical. The assignments of the proton hyperfine coupling constants were confirmed with reference to those of the 2,6-di-t-butyl-4-methyl- and 4-(1-deuteriocyclopropyl)phenoxyl radicals. The β-proton hyperfine coupling constant for the cyclopropyl group and its temperature dependence were precisely determined. Of particular interest is the fact that the observed cyclopropyl β-proton splitting is smaller than the γ-proton splittings (A4β:0.72, A4γ1:0.83, A4γ2: 1.44 G at −70 °C). Based on the modified cos2θ rule, A4β=(1.85〈cos2θ〉−0.10)×A4Me, where the conjugative interaction between the π-system and the cyclopropyl pseudo π-orbital was incorporated, as proposed by Hudson and Bauld, the β-proton splitting was evaluated. The magnitude of the β-proton splitting and its temperature dependence were interpreted in terms of the restricted rotation of the cyclopropyl group in a two-fold potential; the stable conformation was the bisected one. The rotational barrier height, which corresponds to the difference in energy between the bisected and perpendicular conformations, was estimated to be 2.6 kcal/mol. The rotational barrier was attributed to the stabilization of the bisected conformation arising from the conjugative interaction of the aromatic and cyclopropyl moieties.
Solvent-induced Conformational Changes of Arylazo-substituted Polyaspartates
Authors: Ueno Akihiko , Takahashi Keiko , Anzai Jun-ichi , Osa Tetsuo
Published: July 2006

Copolymers of β-benzyl l-aspartate and β-[p-(phenylazo)phenethyl] l-aspartate were prepared and their conformations studied by circular dichroism (CD) spectroscopy. The copolymers with less than 40% azo amino acid residues were found to be left-handed (LH) helical, those with more azo amino acid residues right-handed (RH) helical in 1,2-dichloroethane (DCE) solution. The former undergo LH helix→random coil transition on addition of hexafluoro-2-propanol (HFIP) to their DCE solutions, the latter RH helix→LH helix→random coil transition on addition of HFIP. All polymers in DCE exhibit a negative CD band in the side-chain n-π* transition region. The side-chain π-π* CD band was observed only for the copolymers with the highest azo amino acid residues (67%). Its absolute ellipticity decreases with increasing HFIP content, finally disappearing at 10% HFIP. The sign of the n-π* CD band of the copolymer remains negative irrespective of the helix reversion, its absolute ellipticity being unchanged below 10% HFIP and decreasing on further increase in HFIP content. The results suggest solvent-induced changes in orientation or mobility of the side-chain phenylazo moieties.
The Preparation of 3-Phenyl[1,2,4]triazolo[4,3-a]pyridines and Their Benzologs from N-(Phenylsulfonyl)benzohydrazonoyl Chloride and Pyridines
Authors: Ito Suketaka , Kakehi Akikazu , Matsuno Toshiyuki , Yoshida Jun-ichi
Published: July 2006

3-Phenyl[1,2,4]triazolo[4,3-a]pyridines were obtained in good yields from N′-[α-(1-pyridinio)benzylidene]benzenesulfonohydrazidates, generated from 2-unsubstituted pyridines and N-(phenylsulfonyl)benzohydrazonoyl chloride (2), by oxidation with chloranil. The reaction of quinoline and isoquinoline with 2 gave 1-phenyl-3-phenylsulfonyl-3,3a-dihydro[1,2,4] triazolo [4,3-a]quinoline and 3-phenyl-1-phenylsulfonyl-1,10b-dihydro [1,2,4]triazolo[3,4-a]isoquinoline respectively, both in good yields; they aromatized to the corresponding triazoles by the 1,2-elimination of benzenesulfinic acid on heating.
Syntheses of 2H-1-Benzothiopyran-2-ones (Thiocoumarins) and Related Compounds from Benzenethiols and Diketene
Authors: Nakazumi Hiroyuki , Asada Akira , Kitao Teijiro
Published: July 2006

The products formed by the reaction of benzenethiols with diketene in the presence of H2SO4 are (E)-β-(arylthio)crotonic acids (2) and/or isomeric (Z)-β-(arylthio)crotonic acids and not, as has been reported, S-phenyl 3-oxobutanethioates (1). Compounds 1a–k, as the precursor of thiocoumarins, were prepared from benzenethiols and diketene in the presence of triethylamine. The reaction of 1 with various condensing agents has been examined to prepare 2H-1-benzothiopyran-2-ones (thiocoumarins). It is found that 4-methyl(thiocoumarins) were conveniently prepared by the reaction of 1 with anhydrous aluminium chloride in yields of 16–48%. When 1 was treated with PPA, isomeric 2-methyl(thiochromones) were preferentially obtained in yields of 5–66%, and compound 2 was isolated as an intermediate. The spectral characteristics of 4-methyl(thiocoumarins) have also been described.
Studies of Zone Melting. V. The Solid-Liquid Equilibrium and Zone Melting of the Bibenzyl–Diphenylacetylene System
Authors: Nojima Hidemoto , Akehi Seigou
Published: July 2006

The phase diagram of the bibenzyl–diphenylacetylene system was determined in detail from DSC by using the following equation:

T=α\sqrtF’+β,

where T is the temperature; F′, the corrected fraction melted, calculated by the use of the area for the vertex of the peak instead of the total peak area and α and β, the constants. Then, the melting and freezing temperatures were obtained from a plot of T  vs. \sqrtF′ by the use of the values of β and α+β respectively. The results show the formation of solid solutions with a minimum melting point, at which difficulty in determining the composition often arises from the fact that the slopes of both the solidus and liquidus curves are zero. This could be overcome by multipass zone melting for two samples containing 20 and 30 wt % of diphenylacetylene; after 45 zone passes, the composition of the minimum melting point was found to be 26.4% at the end. Also, by Herington’s theory, it has been revealed that zone-melting experiments were attained almost at equilibrium.
The Transformation of Jervine into 18-Functional C-Nor-D-homosteroids
Authors: Suginome Hiroshi , Yonekura Norihisa , Masamune Tadashi
Published: July 2006

N,O-Diacetyldeoxojervine, obtained by the Wolff-Kishner reduction of jervine followed by acetylation, has been catalytically hydrogenated to (22S,25S)-N,3-O-diacetyl-5α-veratranine-3β,3β-diol. Irradiation in benzene containing mercury(II) oxide and iodine afforded 20-formyl-17β-ethyl-12α-etiojervan-3β-ol 3-acetate which was converted into 17β-ethyl-3β-hydroxy-12α-etiojervan-20-one 3-acetate by dye-sensitized photo-oxygenation of the corresponding morpholine enamine. Reduction to 17β-ethyl-12α-etiojervane-3β,20β-diol 3-acetate with sodium borohydride followed by irradiation in benzene in the presence of mercury(II) oxide and iodine afforded an 18-functional C-nor-D-homosteroid, (20R)-18,20-epoxy-17β-ethyl-12α-etiojervane-3β,20β-diol. The configuration of the methyl group on the tetrahydrofuran ring has been shown to be α on the basis of the NMR spectrum, confirming a previous assignment.
Study on V2O5–Al2O3 Catalyst by Means of XPS for the Reduction of Nitric Oxide with Ammonia
Authors: Nishijima Akio , Kiyozumi Yoshimichi , Ueno Akifumi , Kurita Minoru , Hagiwara Hiroyuki , Sato Toshio , Todo Naoyuki
Published: July 2006

The V2O5–Al2O3 catalyst used for the NO reduction in flue gas from a sintering furnace was studied by means of X-ray photoeloctron spectroscopy and X-ray microanalysis. Effects of dust components accumulated on the catalyst and of electronic states of vanadium ions on catalytic activities were discussed.
Analysis of the Short-range Force Including the r−s-type Functional Force
Authors: Miura Mitiko , Shiro Yuji , Murata Hiromu
Published: July 2006

In treating the lattice dynamics strictly, it is important to separate the short-range forces into various kinds according to their characters: covalent-bond, characteristic repulsive, and van der Waals. The purpose of this paper is to describe a method of separation and an appropriate treatment which is applicable to any crystal with any properties. For the repulsive and the van der Waals interactions, we apply the Jones-type potential function, varying as an inverse power of the distance. The results indicate that the repulsive force serves to emphasize the ionicity in the crystal-force field and that the covalent-bond force cannot be represented reasonably by the use of the valence force to such a crystal as the wurtzite structure, forming a coordination lattice.
Equilibria of Complex Formation between Bivalent Metal Ions and 3,3′-Bis[N,N′-bis(carboxymethyl)aminomethyl]-o-cresolsulfonphthalein
Authors: Murakami Sadaaki , Ogura Kotaro , Yoshino Takashi
Published: July 2006

The complex formation equilibria between several bivalent metal ions and 3,3′-bis[N,N′-bis(carboxymethyl)aminomethyl]-o-cresolsulfonphthalein (XO) have been investigated potentiometrically and spectrophotometrically. The metal ions studied here were Co(II), Ni(II), Cu(II), Zn(II), Pb(II), and Cd(II). The formation constants and visible-absorption-spectrum parameters of these metal complexes have been determined. It has been found that all these metal ions form 1:1 and 2:1 (metal: XO) complexes with XO. Moreover, the complex of each composition changes into one of several protonated ones depending on the pH of the solution. The probale structures of the complexes in solution are discussed.