bluuebunny/crossref_metadata_2025 huggingface dataset:
The Reaction of the Hydroxamic Acid Group in Polymer with p-Nitrophenyl Acetate
Authors: Kunitake Toyoki , Okahata Yoshio , Ando Reiko
Published: July 2006

Water-soluble copolymers containing protected hydroxamate groups were prepared by radical copolymerization of acetyl N-phenylacrylohydroxamate and acrylamide, and the hydroxamic acid group (PHA) was unmasked by treating it with hydroxylamine. In acetylation with p-nitrophenyl acetate (1.4 v/v% CH3CN–H2O, 30 °C) the PHA unit was less reactive than the corresponding monomeric compound. When the PHA content was low (3 mol%), the reactivity of a given PHA anion (true reacting species) was invariant (9.1 M−1 S−1) over a wide range of the dissociation of the PHA unit. However, in the case of the copolymer of a higher PHA content (11 mol%) the reactivity decreased as the neutralization of the PHA anion progressed. This phenomenon was attributed to the intramolecular aggregation of the undissociated PHA side chain. The deacylation rate of the acetylated PHA unit was comparable to those of the monomeric counterparts, in contrast with the acylation process. Finally, the probable role of the PHA unit as catalyst for the ester hydrolysis was discussed.
Studies of Unusual Amino Acids and Their Peptides. V. The Synthesis and the Absolute Configuration of β(2-Thiazolyl)-β-alanine Present in Bottromycin
Authors: Seto Yasuhiko , Torii Kazuhira , Bori K\={o}ichi , Inabata Kenichiro , Kuwata Shigeru , Watanabe Hiroshi
Published: July 2006

In order to obtain an optically-active β-(2-thiazolyl)-β-alanine, N-acyl-l-aspartic α-thionamide-β-methyl ester was condensed with diethyl bromoacetal, but the amino acid thus obtained showed no perceptible optical activity. The racemic amino acid, however, could be resolved into its antipodes by treating its phthalyl derivative with brucine. Thus, the (+)-amino acid, a constituent of bottromycin, was isolated in a pure state; it was determined to belong to the l-series by examining its optical behavior. This amino acid was proved to racemize easily under the conditions of the acid hydrolysis of bottromycin.
Fractionation of Polyvinyl Chloride Pitch by Vacuum Sublimation
Authors: Kamo Mutsukazu , Kanda Hisao , Sato Yoichiro , Setaka Nobuo
Published: July 2006

Pitch prepared by heating polyvinyl chloride at 400 °C (PVC pitch) was fractionated by vacuum sublimation. The fractions were studied by means of elementary analysis, determination of molecular weight, IR spectroscopy and NMR spectroscopy. It was found that each fraction has a characteristic constituent as follows: 1) Zones 1 and 2 are composed of some aromatic nuclei with 3–4 rings and 3–5 rings linked with aliphatic chains, respectively; 2) Zones 3 and 4 are composed of condensed aromatic nuclei with 6–8 rings and 6–7 rings, respectively; 3) In zone 5, aromatic nuclei have 2–4 aromatic rings on an average, and the ratio of the aliphatic group is higher than that of other zones; 4) The sublimation residue is mainly composed of condensed aromatic nuclei, and the ratio of aromatic hydrogen to aliphatic hydrogen in the residue is the highest.
The Alkylation of Phenol over the ZnO–Fe2O3 Catalyst
Authors: Kotanigawa Takeshi , Shimokawa Katsuyoshi
Published: July 2006

The highly selective alkylation at the ortho position of phenol was caused by the dissociative adsorption of phenol; it was discussed by taking account of the acidic and the basic properties of the ZnO–Fe2O3 catalyst.
Energized Vinyl Radical Formation in the Photolysis of Ethylene
Authors: Hara Hiroshi , Tanaka Ikuzo
Published: July 2006

Energized vinyl radical formation was found in the primary process of the 1634 Å photolysis of ethylene in the pressure region up to about 1 atm. The energized vinyl radical either decomposes unimolecularly to give acetylene and a hydrogen atom, or is deactivated to a stable vinyl radical at collision.
The Reactions of Several Carbonyl Compounds with Hexamethylphosphoric Triamide
Authors: Arimatsu Seiji , Yamaguchi Ryohei , Kawanisi Mituyosi
Published: July 2006

Non-enolizable carbonyl compounds were found to undergo intriguing reaction upon heating with hexamethylphosphoric triamide; benzophenone gave 1,1,2,2-tetraphenylethane and benzophenone methylimine, while fluorenone afforded 9-methylfluorene, 9-dimethylaminofluorene, and fluorene. In contrast, anthrone, an enolizable compound, was completely recovered unchanged under the the same reaction conditions.
A Study of the Upper and Lower Bounds of the Second-order Perturbation Energy
Authors: Yamabe Tokio , Tanaka Kazuyoshi , Ishimaru Shingo , Fukui Kenichi
Published: July 2006

A method of calculation for the upper and lower bounds of the second-order perturbation energy is investigated. The expression for the upper bound is based on Hylleraas’s variation perturbation condition and is an improved version of that obtained by Goodisman. The lower bound is based on the Temple-type inequality and is an improved version of that by Prager and Hirschfelder. The result is numerically tested for examples of the polarizability of a hydrogen atom and the coefficients (C5 and C8) of the dispersion force between two separated hydrogen atoms, yielding fairly good results. Particularly, the results of the upper bound for C8 are the best so far calculated in a non-empirical way.
Asymmetric Synthesis with Sugar Derivatives. V. The Synthesis of α-Hydroxy Acids on Insoluble Polymer Supports
Authors: Kawana Masajiro , Emoto Sakae
Published: July 2006

The styrene-2% divinylbenzene copolymer containing 1,2-O-cyclohexylidene-5-O-trityl-α-d- or -l-xylofuranose (d- or l-3a) was prepared. Asymmetric Grignard additions to benzoylformate (3b) and pyruvate (3c) were carried out using these polymers as chiral ester-components. Enantiomers of α-hydroxy acids, such as atrolactic acid (4) and 2-hydroxy-2-phenyl-2-(p-tolyl)acetic acid (5), were obtained in relatively good synthetic and optical yields, depending on the use of either d- or l-3a. The optical yields of 4 for the polymer were higher than those for a low-molecular-weight compound, 1,2-O-cyclohexylidene-5-O-trityl-α-d-xylofuranose (8a). It was shown that the polymer could be used repeatedly.
Kinetics of the Autoxidation of Substituted Anthranols to Anthraquinones in Buffered Aqueous Dioxane
Authors: Ogata Yoshiro , Nate Kazuo , Yamashita Mitsuji
Published: July 2006

Autoxidation of 2-substituted anthranols to the corresponding anthraquinones in alkaline buffered aqueous dioxane (2:1 in vol) has been studied kinetically at 35 °C by means of the manometric method. The relative rate constants for the autoxidation of anthranyl oxide ions have been evaluated, in which dissociation of anthrones is taken into account. Application of substituent effect on the one-electron transfer to the oxide ion to the Hammett equation gives an average ρ-value of −1.5, which was little influenced by pH of the solution.
A Base-induced Elimination Reaction of Phenylsulfonylacetates. II. Effects of the Base and the Solvent on the Stereochemistry of Elimination
Authors: Mano Hiroshi , Sera Akira , Maruyama Kazuhiro
Published: July 2006

The base-induced elimination reaction of 1,2-diphenylethyl phenylsulfonylacetate was investigated in a variety of base–solvent systems. A stronger base was found to facilitate syn elimination. The addition of crown ether caused a remarkable change in the stereochemistry of elimination from syn to anti. In aprotic solvents, an overwhelming syn elimination was observed.
The Configuration at C–21 of Hydroxyhopanone
Authors: Sekiguchi Kazuo , Kanemoto Hiroaki , Hirao Yoji , Tsuyuki Takahiko , Takahashi Takeyoshi
Published: July 2006

Hydroxyhopanone (1) was converted via two alternative routes (1→9→11a→12→14→15→16 and 1→10→17→18→19→20) to A-neohop-21-ene (16) and A-neohop-3-ene (20), respectively. These unsaturated hydrocarbons (16 and 20) were found to be identical; this provided evidence to confirm the 21β-H configuration for 1.
Studies on Benzoquinolines(f) and (h). Part II
Authors: Tyagi Rameshwar P , Joshi Bhuwan C
Published: July 2006

3-Hydrazino-1-methyl, 1-hydrazino-3-methylbenzo(f) quinoline (IA, IIA) and 2-hydrazino-4-methyl, 4-hydrazino-2-methylbenzo(h) quinoline (IIIA, IVA) were reported to give triazines and diazepines with nitrous and formic acids. It would be interesting to study the reactions of IA–IVA with acetylacetone and ethyl acetoacetate respectively.
Mechanism of the Oxygen Exchange Reaction of n-Butyl Methyl Sulfoxide in Sulfuric Acid
Authors: Oae Shigeru , Moriyama Masaru , Numata Tatsuo , Kunieda Norio
Published: July 2006

Mechanistic investigations of the concurrent oxygen exchange and racemization reactions of 18O-labeled and optically active n-butyl methyl sulfoxide in sulfuric acid of various concentrations have been carried out. The kinetic data were analyzed in the light of kex/krac values, activation parameters, correlations between the rates and acidity functions, etc. The results seem to suggest that the reaction proceeds through an A-1-like route to afford a cation radical (–\overset+·S–) or a dication (–\overset++S–) intermediate, followed by a fast nucleophilic attack of water to give the starting sulfoxide.
High-precision Flow Meter for Gas Chromatography
Authors: Hori Yoshio , Kobayashi Riki
Published: July 2006

A gas-chromatographic apparatus with an empty tubing in place of a packed column can be used as a flow meter. The detector signal, processed by a differentiatortimer system, gives a precision of 0.06% in the measurement of the flow rate.
A Novel Rearrangement of Styryl Sulfoxide Induced by Phosphorus Pentachloride
Authors: Miyamoto Norioki , Fukuoka Daisuke , Utimoto Kiitiro , Nozaki Hitosi
Published: July 2006

The reaction of both isomers of methyl styryl sulfoxide (Ia) with the title chloride affords methyl phenacyl sulfide (IIa) and phenyl(α-methylthio)acetaldehyde (IIIa) besides β-chlorostyryl methyl sulfide (IVa). Phenyl styryl sulfoxide reacts similarly.
The Thermal Decomposition and Reduction of Silver(I) Oxide
Authors: Nakamori Issei , Nakamura Hidetsugu , Hayano Toshiyuki , Kagawa Shuichi
Published: July 2006

The thermal decomposition of silver(I) oxide and its reduction with reductive gases, such as ethylene, hydrogen, and carbon monoxide, have been studied by using a fixed-bed flow reactor. Under isothermal conditions, each reaction gave a sigmoidal shape to the fractional decomposition vs. time curves, and these curves were in good agreement with Avrami’s equation. The temperature at which the reaction commenced corresponded well to the chemical affinity of the reaction, and a linear free-energy relationship holds between the apparent activation energy and the standard enthalpy change of the reaction. In the thermal decomposition, an enlargement in particle size resulting from the melting and sintering of the product silver was recognized, but in the reduction the particle size scarcely varied during the reaction. On the basis of these results, the mechanism of each reaction was discussed.
An Infrared Study of the Steric Effects of Alkyl Substituents on the N–H Stretching Absorptions of sym-Dialkylureas
Authors: Mido Yoshiyuki
Published: July 2006

By examining their N–H stretching absorptions in the hydrogen-bonding system, the steric effects of the substituent on the C=O or N–H group have been studied for sym-disubstituted alkylureas of the RHNCONHR′ type in carbon tetrachloride. By comparing the estimated percentage of the monomer, it is concluded that the steric effects are not large enough to convert the trans conformation into the cis conformation, though the branched alkyl groups may prevent another molecule from approaching more strongly than the normal alkyl groups. Correlations among some spectral parameters have been examined, such as the estimated percentage of the monomer, the frequency shift upon hydrogen-bond formation, the apparent integrated absorption intensity, and the halfintensity width of the associated band.
The Electro-Initiated Polymerization of Acrylamide in an Aqueous Solution of Trifluoroacetic Acid and Potassium Trifluoroacetate
Authors: Ogumi Zenpachi , Tari Isao , Takehara Zenichiro , Yoshizawa Shiro
Published: July 2006

The electro-initiated polymerization of acrylamide was investigated in an aqueous solution of trifluoroacetic acid and potassium trifluoroacetate. An oligomer with a molecular weight of 4000–6000 was thus obtained. The initiating ability of Kolbe’s intermediate radicals was recognized by an analysis of the fluorine contained in the polymerized products as the end group. Kolbe’s intermediate radicals, R·, react with monomers, M, to form RM·, which takes the paths of polymerization and other reactions. The rate of reaction to form RM· is so fast that no Kolbe’s dimer, C2F6, is obtained. Gas analysis clarified the ratio of CF3COO· to CF3·, which reacted with the monomer. The comparison of the molecular weights as measured by the two different methods suggests that the coupling reaction of radical ends terminates the propagation reaction. The rate of oligomer production was independent of the current density.
Force Field of Allene
Authors: Tanabe Kazutoshi , Saëki Shinnosuke
Published: July 2006

The force constants based on the simple or modified Urey-Bradley, and the general force fields have been determined from the observed fundamental frequencies, Coriolis coupling constants and centrifugal distortion constants of allene C3H4, C3D4 and C3H2D2 by the damped least-squares method. It is concluded that the simple or modified UBFF is not suitable for reproducing the observed data. In order to attain the best fit between the observed and calculated values, new bond-angle interaction constants q(CH, CCC) and q(CC, HCH) as well as the bond-bond and angle-angle interaction constants p and l should be added to the simple UBFF.
The Microwave Spectrum of 3,3,3-Trifluoropropene
Authors: Saito Shuji , Makino Fumio
Published: July 2006

The microwave spectra of normal, 2–13C, and three monodeuterated isotopic species of 3,3,3-trifluoropropene have been studied. The combined structure of ro and rs was obtained from the rotational constants observed. It has been necessary to take account of a tilt angle of the symmetry axis of the trifluoromethyl group. The following structural parameters have been determined: r(C–C)=1.489±0.002Å, r(C=C)=1.312±0.010Å, r(C–H1)=1.085±0.011 Å, r(C–H2)=1.092±0.009 Å, r(C–H3)=1.109±0.003 Å, ∠F–C–F=106.8±0.3°, ∠C–C=C=124.8±0.4°, ∠C=C–H1=120.6±1.0°, ∠C=C–H2=122.8±1.0°, ∠C=C–H3=121.2±1.0°, and θt=1.0±0.8° on the assumption that r(C–F)=1.345±0.003Å, where θt denotes the tilt angle of the CF3 top axis relative to the C–C bond away from the double bond of the vinyl group. The components of the electric dipole moment have been determined to be μa=2.331±0.014 D and μb=0.698±0.025 D; these values give a total dipole moment of 2.433±0.020 D at an angle of 7±1° with the symmetry axis of the trifluoromethyl group. The relative intensity between the rotational transitions in the ground state and in the first torsionally-excited state has been measured. The torsional frequency has been determined to be 88±25cm−1.
The Reaction of Hot Deuterium Atoms with cis-2-Butene
Authors: Sato Shin , Nishida Seishi , Hosoya Kiyoshi
Published: July 2006

The photolysis of deuterium iodide at the wavelength of 2288 Å was carried out in the presence of cis-2-butene and iodine at 40 °C. Among the products, hydrogen (D2 and HD), methane (CH3D), propylene (CH3CH=CHD), n-butane (CH3CHDCHDCH3), and 1-butene were measured as a function of the pressure of cis-2-butene. The formation of HD at higher pressures of cis-2-butene was attributed to the abstruction of H atoms from cis-2-buteneby hot D atoms. This reaction accounted for 8% of the total D atom-reaction. The formations of CH3D, C3H5D, and C4H8D2 were well explained by the successive reactions of hot butyl radicals, C4H8D*.
The Radiolytic-chain Dechlorination of Polychlorinated Biphenyls in Alkaline 2-Propanol Solutions
Authors: Sawai Takeshi , Shimokawa Toshinari , Shinozaki Yoshiharu
Published: July 2006

The radiolysis of solutions of polychlorinated biphenyls (PCB’s) and potassium hydroxide in simple aliphatic alcohols was studied. The major products in alkaline 2-propanol solutions were potassium chloride, acetone, lower chlorinated biphenyls, and biphenyl. Their yields increased and the concentration of the hydroxide ions decreased with the dose. Acetone and potassium chloride were formed in high yields, and their concentrations were almost equal to the diminution in the hydroxide ions. The dechlorination yield was determined as a function of the dose, the dose rate, and the concentrations of PCB’s, potassium hydroxide, and organic solutes. The chain-dechlorination reaction proceeded in the alkaline 2-propanol solution, but not in alkaline methanol, ethanol, 1-propanol, and butanols. The 2-propoxide radical anion, which is formed by the electron transfer from the hydroxide ion to the 2-propanol radical, is the chain carrier for the dechlorination reaction of PCB’s in alkaline 2-propanol solutions. The mechanism is discussed in detail.
Photolysis of 2,2-Diethoxy-2,3-dihydrophenalene-1,3-dione
Authors: Otsuji Yoshio , Wake Shigeo , Maeda Eiichi , Imoto Eiji
Published: July 2006

Irradiation of 2,2-diethoxy-2,3-dihydrophenalene-1,3-dione (6) with a pyrex-filtered high-pressure Hg arc lamp afforded acetaldehyde, 2-ethoxy-3-hydroxyphenalene-1-one (7) and bis-2-(2-ethoxy-l,3-dioxo-2,3-dihydro) phenalenyl (8). Mechanistic studies revealed that the first step of this photoreaction was a homolytic fission of the C–OC2H5 bond to 2-(2-ethoxy-1,3-dioxo-2,3-dihydro)phenalenyl radical (9) and ethoxyl radical. This homolytic fission occurred mostly from the triplet and in part from the singlet excited state of 6. Dimerization of 9 gave 8 and the disproportionation between 9 and ethoxyl radical gave acetaldehyde and 7. The photochemical behaviors of a variety of triketone derivatives were discussed.
Studies of the Chemiluminescence of Several Xanthene Dyes. VI. A Kinetic Analysis of a Blue-fluorescent Product in the Chemiluminescent Reaction of Eosin Y with Hydrogen Peroxide
Authors: Kamiya Isao , Aoki Keizo
Published: July 2006

In the present study, we found that the absorbance at 395 nm of the chemiluminescent reaction system of eosin Y with hydrogen peroxide initially increased to a maximum, and then gradually decreased. From the finding that the absorption spectrum of a chromatographically-isolated blue-fluorescent product (ME) showed a peak at the same wavelength (395 nm), we could confirm that the increment of the absorbance at 395 nm (Δ395) was mainly due to the generation of ME; we then extended the investigation of the mechanism for the chemiluminescent reaction by a kinetic analysis of ME. The observed value of Δ395 could be approximately calculated by the expression of [ME], which was derived from a kinetic scheme proposed in the previous paper. The ratio of the generation rates of ME in different media, which was calculated from the observed values of Δ395, was in good agreement with that estimated from the curves of the chemiluminescence emission intensity versus the time measured in the media. These results gave additional evidence in support of the view that the blue-fluorescent species is the primary excited product in the reaction.
Estimation of Individual Ionic Activity Coefficients from Conductivity Data on Strong Electrolytes in Dilute Aqueous Solutions
Authors: Tamamushi Reita
Published: July 2006

The individual ionic activity coefficients of strong electrolytes in dilute aqueous solutions are derived from the ionic conductivity data, using the Debye-Hückel-Onsager theory of strong electrolyte solutions. The mean activity coefficients computed by the present method are in good agreement with the experimental values in most of the uni-univalent and some of the uni-multivalent electrolytes studied, which demonstrates the validity of the method in deriving the individual ionic activity coefficients. Comparisons are made of the values of individual activity coefficients of various ions in dilute aqueous solutions of strong electrolytes, as determined by different methods including measurements of potential differences across membranes at varying concentrations. The influence of the ion of opposite sign on the individual ionic activity coefficient has been observed.
The Catalytic Activity of Some Mixed Oxides for Depolymerization of Paraldehyde
Authors: Walvekar S P , Halgeri A B
Published: July 2006

Depolymerization of paraldehyde in benzene catalyzed by SiO2–ZrO2, SiO2–TiO2, Al2O3–ZrO2, TiO2–ZrO2, Al2O3–TiO2 (calcined at various temperatures) has been studied. It is observed that in all the cases the catalytic activity (first order rate constant, k) exhibited a maximum against the temperature of heat treatment of the catalyst. The acid sites at pKa≤−3.0 correlate best with catalytic activity for depolymerization of paraldehyde.
Syntheses of Pyrrolotropone Derivatives from Benzocycloheptene-5,6-dione Monoarylhydrazones. II. Syntheses of Benzo[5,6]cyclohept[l,2-b]-indole-6,11,12-triones
Authors: Fujimori Kunihide , Yamane Kameji
Published: July 2006

Benzo[5,6]cyclohept[1,2-b]indole-6,11,12-triones (benzoindolotropoquinones)(VIIIa–c) were prepared by the oxidation of 11,12-dihydrobenzo[5,6] cyclohept[1,2-b]indol-6-ones (Va–c) with sodium dichromate in acetic acid. Compound VIIIa was rearranged by means of a coned sodium hydroxide solution into a known benzocarbazole-1,4-quinone. The pyrrolotropolone derivative (VII) was also obtained through the ring closure of the 5-hydrazinotropolone derivative (VI).
Dopaquinone and Related Compounds: Reactions with o-Phenylenediamine
Authors: Omote Yoshimori , Hirama Tokuo , Komatsu Toshihiko
Published: July 2006

The oxidation of 4-substituted catechols including DOPA with o-chloranil or cerium(IV) sulfate to give the corresponding o-benzoquinones was examined. The trapping of o-benzoquinones with o-phenylenediamine immediately after oxidation was successfully used to isolate 2-substituted phenazines, the substituents being –CH3, –CH(CH3)2, –(CH2)2CO2H, –(CH2)2CO2CH3, –CH=CHCO2H, –CH=CHCO2CH3, –(CH2)2NHCOC6H5, and –CH2CH(NHCOC6H5)CO2CH3. Dopaquinone was identified in a protected form.
Syntheses and Reactions of Optically Active Polymers. I. Syntheses and Polymerizations of N-Vinylbenzyl-l-amino Acid Derivatives
Authors: Narita Mitsuaki , Akiyama Masayasu
Published: July 2006

N-Vinylbenzyl-l-amino acids were synthesized by the reaction of l-amino acids with formylstyrenes and the subsequent reduction of the condensation products with sodium borohydride. The procedure was performed without protection of the various functional groups of amino acids and racemization was not accompanied by the above process. The method is useful for the synthesis of optically active vinyl monomers containing various amino acids with their intact functionality. As a representative l-amino acid, a variety of N-vinylbenzyl-l-leucine derivatives such as N-methyl-l-leucine, l-leucine ethyl ester, l-leucinol and N-formyl-l-leucine ethyl ester were prepared by means of chemical transformation. These optically active monomers of leucine derivatives were polymerized to optically active polymers.
The Stereochemistry of the Addition of Trimethylaluminum to Decalones and Methyl-substituted Cyclohexanones
Authors: Suzuki Toshimitsu , Kobayashi Toshiaki , Takegami Yoshinobu , Kawasaki Yuzo
Published: July 2006

The addition to the methyl-substituted 4-t-butylcyclohexanone was studied, providing that the β-axial methyl and α-axial methyl groups hindered the axial and equatorial attacks respectively. The results obtained with fused-ring system ketones (four decalones) were explained by considering the similar stereochemical influence of 2-and 3-methylene substituents as corresponding methyl substituents. A rapid conformation equilibrium was also considered for cis-decalones. In addition, the axial attack, especially at a molar ratio of two or more, was found to be hindered by the α-equatorial methyl group. This hindrance was explained by assuming the half-chair form of the cyclohexanone ring in the transition state.
Reaction of Biguanides and Related Compounds. X. The Cyclization of Arylbiguanides with Acyl Isothiocyanates
Authors: Furukawa Mitsuru , Goto Motoo , Hayashi Seigoro
Published: July 2006

The reactions of arylbiguanides with benzoyl and ethoxycarbonyl isothiocyanates gave 4(or 2)-arylguanidino-2(or 4)-phenyl-6-thioxo-1,6-dihydro-s-triazines and 4-arylguanidino-2-oxo-6-thioxo-1,4,5,6(or 1,2,3,6)-tetrahydro-s-triazines respectively, both of which were then converted into the corresponding oxo compounds, in which the thioxo group was converted into the oxo group, by oxidation with hydrogen peroxide. The condensation of 3-amidino-1-aryl-2-thioureas with aryl isothiocyanates afforded 1-aryl-2-arylimino-4-imino-6-thioxo-1,4,5,6-tetrahydro-s-triazines, which were also formed by the pyrolysis of 3-amidino-1-aryl-2-thioureas.
Preparation and Thermal Decomposition of Acyl Carbamoyl Peroxides
Authors: Okazaki Renji , Simamura Osamu
Published: July 2006

Thirteen acyl carbamoyl peroxides, a new class of peroxides, were prepared by addition of peroxy-acids to organic isocyanates and their properties were examined. The thermal decompositions, especially of benzoyl N-(p-nitrophenyl) carbamoyl peroxide and benzoyl N-benzoylcarbamoyl peroxide, were studied in crystalline state and in solution, and it was shown that they decompose via three different mechanisms, involving either an amino-radical, a nitrene or a protonated nitrene, depending on reaction conditions.
Furanoeremophilane-6β,10β-diol and Its Derivatives. New Furanosesquiterpenes from Ligularia japonica LESS
Authors: Tada Masahiro , Moriyama Yoshihiko , Tanahashi Yoshiaki , Takahashi Takeyoshi
Published: July 2006

Three new furanosesquiterpenes have been isolated from Ligularia japonica LESS., and their structures including absolute configurations have been determined as furanoeremophilane-6β-diol (1), 10β-hydroxyfu-ranoeremophilan-6β-yl 2′ξ-methylbutanoate (2), and 10β-hydroxy-6β-methoxyfuranoeremophilane (3).
Synthesis of TACK, a New Chloromethyl Ketone Derivative of Arginine
Authors: Inouye Ken , Sasaki Atsushi , Yoshida Nobuo
Published: July 2006

A synthesis is described of TACK, the chloromethyl ketone derivative of Nα-tosyl-l-arginine, in which a crystalline intermediate NG-nitro-TACK is found to be converted into TACK with hydrogen fluoride without appreciable impairment of the chloromethyl ketone moiety.
Effect of Additive on Solid State Reaction. II. A Thermoanalytical Study of the Effect of Fluorides on the Formation of MgAl2O4 in Initial Stage
Authors: Shimada Shiro , Furuichi Ryusaburo , Ishii Tadao
Published: July 2006

The promoting actions of fluoride on the formation of MgAl2O4 in the initial stage have been studied by means of DTA and high-temperature X-ray diffraction techniques. LiF, NaF, MgF2, GaF2 and BaF2 were used as additives. The three MgO–Al2O3–fluoride (LiF, NaF or BaF2) systems showed similar DTA curves; an endothermic peak (peak-1) in the temperature range 660–800 °C, followed by an exothermic peak (peak-2) at 700–900 °C. The DTA curves for MgO–Al2O3–fluoride (MgF2 or CaF2) systems showed no thermal change. It was found that peak 1 corresponds to Reaction (2), 3MF+2Al2O3=3MAlO2+AlF3, and peak 2 to Reaction (1), 3MgO+2AlF3=3MgF2+Al2O3, and the formation of MgAl2O4. It was concluded that Reaction (2) takes place before the formation of MgAl2O4 and that AlF3 resulting from Reaction (2) initiates the formation of MgAl2O4.
The Photo-desulfurization of Crude Naphtha by UV Irradiation
Authors: Baba Yoshio
Published: July 2006

The photolysis of crude naphtha in the presence of an oxidizing reagent was studied with a view to accomplishing the desulfurization of crude naphtha. The irradiation of crude naphtha consisting of 0.15% sulfur by means of a 200-W high-pressure mercury-vapor lamp, with the aeration of air or oxygen at the flow rates of 5–15 ml/min at 0 °C, resulted in an 80–90% photolysis of the principal mercaptans and sulfides in the crude naphtha within 20 min. The major photo-oxidation products were water-soluble oxygenated sulfur compounds; thus, this process resulted in 67.8% desulfurization when the irradiated naphtha was washed with water. The effects on the photolysis of the molecular weights and the structures of sulfur compounds were also examined with 11 mercaptans and 3 sulfides.
Studies on the Metal Complexes of Quinoxaline Derivatives. III. Metal Chelates of 2-Quinoxalinecarboxylic Acid and Its N-Oxides
Authors: Kidani Yoshinori , Ohira Kazuo , Koike Hisashi
Published: July 2006

Spectrophotometric measurements were carried out for the stability constants of the divalent metal chelates of 2-quinoxalinecarboxylic acid and copper, nickel, cobalt and zinc in a 5% aqueous ethanol solution. Successive stability constants, logK1, of the copper, nickel, cobalt and zinc chelates were 3.30, 2.87, 2.83 and 2.80, respectively. The metal complexes were difficult to dissolve in water. Copper and cadmium afforded both 1 : 1 and 2 : 1 complexes, while other divalent metals such as nickel, cobalt, manganese, zinc and lead resulted in the 2 : 1 complex formation. From the results of IR and Far-IR spectral analyses it was found that the carboxyl group and the ring nitrogen group appear simultaneously in the chelate formation. Copper complexes of 2-quinoxa-linecarboxylic acid 1- and 4-oxides, as well as its 1,4-dioxide were also studied.
Furano Compounds. XXII
Authors: Rao M Kanakalingeswara , Rajagopal S
Published: July 2006

The synthesis of 2′,3′-diphenylfuranobenzoxanthones with the condensed benzene ring at the 5,6; 6,7; and 7,8 positions and with possible antifertility activity is recorded.
Substitution Effect in the Hydrogenation of Monoalkylbenzenes with Ruthenium Catalyst
Authors: Yoshida Toshihisa
Published: July 2006

The influence of substituents on adsorption coefficients as well as rate constants can be understood from the rules of Horiuti-Polanyi and Taft. It is suggested that a nucleophilic adsorption of alkylbenzene and a nucleophilic surface reaction of the adsorbed alkylbenzene with the metal-hydride occur successively.
Molten-State Spectra of Anisyl-p-Benzoquinones
Authors: Aihara Jun-ichi
Published: July 2006

The absorption spectra of three anisyl-p-benzoquinones were observed in the molten state. Interestingly, only the p-anisyl isomer was found to form a selfcomplex in the molten state as in the solid state. Possible explanation was presented for this effect.
The Absorption Spectra of the Electrochemically-generated Unstable Species of Tris(2,2′-bipyridine)cobalt(II) by Reflectivity Measurements at the Silver Electrode in Propylene Carbonate
Authors: Sato Yuichi
Published: July 2006

Tris(2,2′-bipyridine)cobalt(II) perchlorate gave a two-step reduction wave ascribed to [Co-(bipy)3]2+\oversete→[Co(bipy)3]+\overset2e→[Co(bipy)3]− at the Ag electrode in a propylene carbonate solution. The simultaneously-recorded reflectivity-potential curve showed a reflectivity decrease corresponding to each wave on the i-E curve. The absorption spectra due to the unstable reduction products, [Co(bipy)3]+ and [Co(bipy)3]−, were obtained by plotting the reflectivity change vs. the wavelengths.
The Crystal Structure of Bis(1-(2-thiazolylazo)-2-naphtholato)nickel(II)
Authors: Kurahashi Masayasu
Published: July 2006

The crystals of bis(1-(2-thiazolylazo)-2-naphtholato)nickel(II), [Ni(TAN)2], are triclinic with unit-cell dimensions: a=12.38(6), b=12.72(6), c=8.41(4) Å, α=78.9(5), β=95.0(5) and γ=115.1(5)°, Z=2, space group P\bar1. The TAN is terdentate, one nickel atom being surrounded octahedrally by two ligand anions in the mer configuration.
The Preparation of Mixed Cobalt(III) Complexes of N,N-Bis(2-aminoethyl)-glycine with the Carbonate or Oxalate Ion
Authors: Nakashima Syoji , Shibata Muraji
Published: July 2006

mer(N)- and fac(N)-[CoCO3(i-dtma)] complexes have been prepared by the reaction of the tetradentate ligand with the [Co(CO3)3]3− complex. The corresponding [Coox(i-dtma)] complexes have been derived from the mer(N)-carbonato complex.
Miscibility of Lithium with Lithium Chloride and Lithium Chloride–Potassium Chloride Eutectic Mixture
Authors: Nakajima Tsuyoshi , Minami Ryohei , Nakanishi Koichiro , Watanabe Nobuatsu
Published: July 2006

The mutual solubilities of Li–LiCl and Li–LiCl–KCl systems were determined both in liquid-liquid and solid-liquid equilibrium regions. No critical solution temperature was observed for Li–LiCl system. The enthalpy of solution of LiCl in Li was estimated and compared with those for other alkali metal-alkali halides.
The Hydrolysis of Several Purine Nucleosides with Strong Hydrochloric Acid or Cation Exchange Resin
Authors: Suzuki Yoshihisa
Published: July 2006

The rates of hydrolysis were determined for several purine nucleosides with aq. HCl(0.1–4 M) or cation exchange resins(H-form) at 30 °C. The hydrolysis of adenosine with Diaion SK-1B is slower than guanosine while that with HG1 is faster. This discrepancy was discussed.
13C Nuclear Magnetic Resonance Spectra of Unsymmetrical Naphthyridines
Authors: Hirota Minoru , Masuda Hideyuki , Hamada Yoshiki , Takeuchi Isao
Published: July 2006

13C Nuclear magnetic resonance spectra of some naphthyridines were measured and the chemical shifts were compared with those theoretically calculated by an SCF-MO method of π-electron system. Fairly good linear relationship is observed between these values.
A New Condensed Gas Calorimeter. Thermodynamic Properties of Solid and Liquid Dinitrogen Oxide
Authors: Atake Tooru , Chihara Hideaki
Published: July 2006

A new adiabatic calorimeter for use with condensed gases from 1.8 K to room temperature has been constructed. The heat capacity of solid and liquid dinitrogen oxide was measured between 1.9 and 184 K together with the vapor pressure above 146 K. The residual entropy was re-evaluated as 6.0 J K−1 mol−1, which is now closer to R ln2, suggesting that the disorder of molecular end-for-end orientation is perfectly frozen in the solid state. The moments of lattice frequency spectrum were derived from low-temperature heat capacities and hightemperature vapor pressures. The anomalous increase of heat capacity below the triple point was interpreted as arising from thermal creation of orientational defects with the enthalpy of formation 10.8 kJ mol−1. Other thermodynamic quantities determined are as follows: triple point of pure N2O 182.407±0.002 K, heat of fusion 6516±20 J mol−1, entropy of fusion 35.7±0.1 J K−1 mol−1, heat of vaporization at 184.81 K and 101.7 kPa 16544±20 J mol−1, normal boiling point 184.74 K, translational zero-point energy 1.6±0.3 kJ mol−1, Debye temperature corresponding to 3N degrees of freedom 141.0±1.0 K.
The Crystal Structure of the 2:1 Complex of Pyromellitic Dianhydride with trans-4-Methylstilbene
Authors: Kodama Toshiko , Kumakura Shigekazu
Published: July 2006

The 2: 1 complex of pyromellitic dianhydride with trans-4-methylstilbene crystallizes in the Cc space group with four pyromellitic dianhydride molecules and two trans-4-methylstilbene molecules in a unit cell with dimensions of a=12.780, b=7.446, c=15.050 Å, and β=91.09°. In addition to the clearly-defined Laue spots, diffuse streaks elongated perpendicular to the molecular layers were observed with a half period of the b* axis of the reciprocal lattice. The structure was solved from a three-dimensional |E|2 Patterson synthesis and was refined by a block-diagonal least-squares method to the final R value of 0.13 for the visually-estimated 703 reflections. Refinement was difficult, however, because of the large correlation between parameters caused by the disorder. The crystal is built up of molecular layers stacked parallel to the (10\bar2) plane and is disordered in the stacking arrangement of the molecular layers. The pyromellitic dianhydride molecule and one of the benzene rings of the trans-4-methylstilbene molecule are alternately stacked plane-to-plane in infinite columns along [10\bar2]. The ethylene group of the trans-4-methylstilbene molecule joins the two columns. The molecular arrangement of the component molecules resembles those observed in the anthracene, pyrene, and perylene complexes with pyromellitic dianhydride and presents a striking contrast to that of the trans-stilbene complex. The interplanar distances range from 3.25 to 3.56 Å, smaller than that of the trans-stilbene complex.
The Mechanism for the Sulfonation of Olefins with a Sulfur Trioxide–Dioxane Complex
Authors: Nagayama Masuzo , Okumura Osamu , Noda Seiji , Mandai Hiroshi , Mori Akira
Published: July 2006

The rates for the sulfonation of 1-dodecene with the sulfur trioxide–dioxane complex were measured spectrophotometrically. A bimolecular process occurred in this reaction, the rate being proportional to [1-dodecene] [SO3-dioxane]. Furthermore, the stereochemistry of the initial products of the sulfonation reaction between cis or trans-2-butene and the sulfur trioxide-dioxane complex was studied. An equimolar amount of sulfur trioxide–dioxane (1 : 1) was added to cis- or trans-2-butene in chloroform to give the sultone, (I) or (II); (I) 1.5(q), 4.7–5.1 (m), JAB 7.9, JBC 8.0, JCD 6.0 Hz; (II) 1.5(q), 4.2–4.6(m), JAB 6.8, JBC 5.4, JCD 6.8 Hz. These results indicate that the 2,3-butanesultones were produced stereospecifically from the corresponding 2-butene isomers. Similarly, the sulfonation of cis- or trans-2-pentene with sulfur trioxide-dioxane gave the corresponding 2,3-pentanesultones.
A Study of the Recoil Labeling of Fluothane with 82Br during Neutron Irradiation
Authors: Kudo Hiroshi , Mogi Terutomi , Hoizumi Kiyoshi
Published: July 2006

1,1,1-Trifluoro-2-chloro-2-bromoethane labeled with 82Br (fluothane-82Br) was purely separated from neutron-irradiated fluothane by means of a gas-chromatographic technique. The maximum radiochemical yield of fluothane-82Br was 38.3% when the target material was irradiated with neutrons to nvt of 3.4×1016 n·cm−2. Of the many organic species produced by the recoil events following the radiative neutron capture and subsequent (I.T.) processes, CF382Br and CF3CHBr82Br were also identified. In order to elucidate the mechanism of recoil labeling, the scavenger effects were examined in the CF3CHClBr–Br2 system, Br2 being used as a radical scavenger. The “high-energy” yields of CF3CHCl82Br thus estimated were approximately 3.6 to 4.8%. It was suggested that most of the 82Br-labeled species were formed through the “thermal” processes including the reaction of 82Br with the organic radicals produced by the radiolysis of the parent fluothane.
The Estimation of the G-Values for the Ionization and Excitation of Noble Gases Irradiated by 100 keV Electrons
Authors: Sato Shin , Okazaki Kiyoshi , Ohno Shin-ichi
Published: July 2006

The binary-encounter collision theory has been applied to the calculation of the G-values for the ionization and excitation of noble gases irradiated by 100 keV electrons. The G-values obtained were as follows in the order of He, Ne, Ar, Kr, and Xe: 2.27, 2.19, 2.81, 3.20, 3.45 for G(electrons), 0.85, 1.55, 1.92, 1.64, 1.51 for G(singlet states), and 0.17, 0.07, 0.13, 0.23, 0.39 for G(triplet states). The method of the calculation and the significance of the results were discussed.
Interactions of 1-Substituted 2,4-Dinitrobenzenes with Methoxide and Hydroxide Ions in Dimethyl Sulfoxide with a Rapid Scan Spectrophotometer
Authors: Hasegawa Yoshinori
Published: July 2006

The interactions of m-dinitrobenzene and 1-substituted 2,4-dinitrobenzenes with sodium methoxide in meth-anolic dimethyl sulfoxide were studied with a rapid scan spectrophotometer. A similar study of 1-substituted 2,4-dinitrobenzenes with sodium hydroxide in aqueous dimethyl sulfoxide was carried out. Except for a few cases, the first transient colored-complexes of 3-substituted 2,6-dinitrocyclohexadienates were observed at initial stages before the complete formation of second colored-complexes having the π-electronic structures of 1,3-dinitropentadienyl anion.
Thermochemical Studies on Platinum-Olefin Complexes. I
Authors: Sen\={o} Manabu , Iwamoto Kazutoshi , Asahara Teruzo
Published: July 2006

Using a twin-type calorimeter, the enthalpy changes of solutions and reactions with aqueous KCN solution of Zeise’s salts, K[PtCl3(olefin)], were measured. As ligand olefins, ethylene, propylene, 1-butene, 1-pentene, and 1-hexene were employed. It was estimated from a thermochemical analysis that the order of strength of platinum-olefin bonding is as follows; K[PtCl3(C3H6)]\gtrsimK[PtCl3(C3H6)]\gtrsimK[PtCl3(1-C6H12)]\gtrsimK[PtCl3(1-C4H8)]\gtrsimK[PtCl3(1-C5H10)]. This order was compared with the data of infrared spectra and both the results coincide with each other.
Differential Thermal Analysis of Some Tervalent Metal Chelates of 1,5-Dialkylpentane-2,4-dionates
Authors: Yoshida Isao , Kobayashi Hiroshi , Ueno Keihei
Published: July 2006

In connection with the purification of metal chelates by zone refining, thermal properties of the following β-diketone chelates of tervalent cobalt(III), aluminum(III), iron(III), manganese(III), and chromium(III) were investigated by differential thermal analysis (DTA). The β-diketones used in this study were heptane-3,5-dione, nonane-4,6-dione, 2,6-dimethylheptane-3,5-dione, 2,8-dimethylnonane-4,6-dione, 2,2,6,6-tetramethylheptane-3,5-dione, and tridecane-6,8-dione. Metal chelates of the alkyl substituted pentane-2,4-diones showed a lower melting- and higher decomposition temperature in comparison with the pentane-2,4-dionates. Discussion is given on the effects due to the structures of the alkyl substituents upon thermal properties of the hexacoordinate metal chelates.
Formation of Cubic Molybdenum Carbide by the Carbonization of MoO3 with Plasma Arc and Properties of the Products
Authors: Matsumoto Osamu , Saito Michio , Yoshino Takashi
Published: July 2006

The formation of cubic molybdenum carbide (α-MoC1−x) by the carbonization of MoO3 with graphite by heating with argon plasma arc was studied. α-MoC1−x including a small amount of hexagoanl η-MoC1−x. was formed. By the carbonization of mixture of MoO3 and TiO2 with graphite, a cubic solid solution of Mo–Ti–C system was formed. Chemical and X-ray analyses showed that the cubic form is defective in carbon content. The density of the cubic form was in agreement with that determined by means of X-ray diffraction. The products were found to be superconductors, the transition temperature varying with composition. The highest transition temperature 11.7 K was obtained for Mo0.95TiO0.05C0.75.
Nitration of Decamethylbiphenyl and 2,3,5,6-Pentamethyl-2′,3′,4′,5′,6′-pentachlorobiphenyl with Fuming Nitric Acid. Exclusive Ortho Orientation for the Side-chain Attack
Authors: Suzuki Hitomi , Yagiu Osamu , Hanafusa Terukiyo
Published: July 2006

Products obtained by the reaction of the title compounds with fuming nitric acid in dichloromethane were investigated. Decamethylbiphenyl gave 6,6′-bis(nitrooxymethyl)-2,2′,3,3′,4,4′,5,5′-octamethylbiphenyl or 2,6,6′-tris(nitrooxymethyl)-2′,3,3′,4,4′,5,5′-heptamethylbiphenyl as the major product, depending on the amount of nitrating agent. 2,3,4,5,6-Pentamethyl-2′,3′,4′,5′,6′-pentachlorobiphenyl similarly gave 6-nitrooxymethyl-2,3,4,5-tetramethyl-2′,3′,4′,5′,6′-pentachlorobiphenyl or 2,6-bis(nitrooxymethyl)-3,4.5-trimethyl-2′,3′,4′,5′,6′-pentachlorobiphenyl. Some plausible reaction sequences for the exclusive ortho attack on the alkyl side-chains of biphenyl systems have been suggested.
Studies on Cyclic Dipeptides. II. Isomerization among cyclo(-4-Hydroxyprolyl-4-hydroxyprolyl-)s and a Novel Conversion of d-allo-Hydroxyproline to l-Hydroxyproline
Authors: Eguchi Chikahiko , Kakuta Akio
Published: July 2006

The isomerization among c-l-Hyp-l-Hyp (1), c-l-Hyp-d-aHyp (2) and c-d-aHyp-d-aHyp (3) has been examined in ethanolic sodium ethoxide at 25–78 °C as well as in aqueous solutions at 75–250 °C. At equilibrium state, 1 was predominant and 2 was not found at all in the reaction mixture. By the use of this isomerization reaction and the difference of solubility between 1 and 3, 3 could be converted almost quantitatively to 1. The mixture of 1 and 3 was obtained in good yield directly from d-aHyp or l-Hyp by heating in water or ethylene glycol. 1 was hydrolyzed quantitatively to l-Hyp by acid. Thus, l-Hyp was obtained with the yield of 59% from d-aHyp by combination of preparation, isomerization and acid hydrolysis of cyclic dipeptide.
Chemical Studies on Tuberactinomycin. VII. Synthesis of γ-Hydroxy-β-lysine
Authors: Wakamiya Tateaki , Teshima Tadashi , Kubota Ichiro , Shiba Tetsuo , Kaneko Takeo
Published: July 2006

γ-Hydroxy-β-lysine is a new basic amino acid isolated from the hydrolyzates of antitubercular peptides, tuberactinomycin A and N. In order to confirm the structure and establish the stereochemistry of the amino acid, two diastereoisomers of γ-hydroxy-Dl-β-lysine were synthesized by Arndt-Eistert synthesis via β-hiydroxyornithine. Synthetic erythro and threo isomers were found to be identical spectroscopically and chromatographically with the corresponding forms obtained from the antibiotics respectively.
Conformational Analysis About N–N Bond by NMR Spectroscopy: N-Sulphonyl Derivatives of N-Aminoimides of Anthracene-Citraconic Anhydride and Naphthalene-Maleic Anhydride Adducts
Authors: Verma S M , Rao O Subba , Sinha K O P
Published: July 2006

A series of N′,N′-disulphonyl and N′-sulphonyl-N′-acetyl derivatives of N-amino-9,10-dihydroanthracene-9,10-endo-α-methyl-α,β-succinimide and N-amino-1,2,3,4-tetrahydro-1,4-etheno/ethano-naphthalene-2,3-exo/endo-dicarboximides with a benzo ring in the cage-moiety were prepared and their NMR spectra were studied. Shielding constants of the substituents provide evidence for the non-eclipsed conformations of the N′-substituents with the ring carbonyls. The preferred conformations of N′-sulphonyl-N′-acetyl derivatives are explained on steric grounds. In N′-tosyl-N′-acetyl derivatives the tosyl group takes up a fixed conformation about N′-SO2 bond in which the aryl part of the tosyl group projects away from the cage-moiety.
The Crystal and Molecular Structure of Dimeric [3-(Salicylideneamino)-1-propanolato(2–)]copper(II)
Authors: Nassiff Peter J , Boyko E R , Thompson Loren D
Published: July 2006

The crystal structure of dimeric [3-(salicylideneamino)-1-propanolato(2–)]copper(II) has been determined by X-ray diffraction. The two copper atoms are square planar with a separation of 3.021 (4) Å and are bridged with aliphatic oxygens. The unusually low antiferromagnetism, explained by superexchange, has been correlated with the Cu–O–Cu angles of similar complexes.
Stereochemistry of Ionic Thiol Addition to Acetylenic Ketones
Authors: Omar Mohamed Tawfik , Basyouni Mohamed Nabih
Published: July 2006

Piperidine-catalysed addition of thiols to benzoyl- and p-chlorobenzoyl-phenylacetylenes in benzene gave a mixture of (E)- and (Z)-1-aryl-3-arylthio-3-phenyl-2-propen-1-ones. However, in methanol or aqueous 1,4-dioxane only the (Z)-isomers were obtained. Configurational assignments to the isomers were based on NMR, UV, and IR spectroscopy.
The Isomerization of Purine Nucleosides in a Dilute Alkaline Solution
Authors: Suzuki Yoshihisa , Yatabe Setsuko
Published: July 2006

A further study of the isomerization of inosine (1a) in a dilute alkaline solution has revealed the formation of α-pyranbsyl isomer (4a) and its β-isomer (3a). Adenosine (1b) was isomerized at 130 °C for 12 hr at pH 10, giving α-furanosyl (2b) (2% yield), β-pyranosyl (3b) (11%), and the α-pyranosyl isomer (4b) (0.8%), respectively; 65% of the 1b also remained. 9-β-d-Ribopyranosyl-6-mercaptopurine (3c) was prepared through this reaction from the corresponding β-furanoside (1c). Arabinosyl or xylosyl purine nucleosides were also isomerized, whereas neither 2′-deoxy nor 2′-substituted nucleoside showed any clear evidence of isomerization. In conclusion, the purine base and the 2′-hydroxyl anion are essential to the alkaline isomerization of nucleosides. By means of NMR, both 4a and 4b were found to have a 1C conformation, while 3a and 3b have a Cl conformation.