bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coenzyme Models. XII. Kinetics and Mechanisms of 1,4-Dihydro-nicotinamide Reduction of Carbon-Carbon Double Bonds. Influence of Added Mg2+ Ion and Acetic Acid
Authors: Shinkai Seiji , Kusano Yumiko , Ide Toyoko , Sone Takaaki , Manabe Osamu 
Published: July 2006

Abstract
Nonenzymatic dihydronicotinamide reduction of carbon-carbon double bonds occurs with the aid of Mg2+ ion or acetic acid. The role of Mg2+ ion and acetic acid is discussed on the basis of spectral studies, kinetic measurements, and product analyses. The addition of Mg2+ ion caused the shift of the NMR peak of substrate α-proton to lower field, and the magnitude was parallel to the yield of reduced methylene derivatives. Kinetic studies suggested that the dihydronicotinamide reduction in the presence of Mg2+ ion is most reasonably understood by assuming a competitive complexation of dihydronicotinamide and substrate with Mg2+ ion. On the other hand, acetic acid aids the reduction by means of general acid catalysis, but an alternative mechanism is suggested for the reduction of benzylidenemalononitrile.
Oxidation of 2,5-Dimethoxyacetophenone Derivatives with Thallium(III) Nitrate in Trimethyl Orthoformate–Methanol. I
Authors: Maruyama Kazuhiro , Kozuka Tadashi 
Published: July 2006

Abstract
Alkyl-substituted 2,5-dimethoxyacetophenones were oxidized with thallium(III) nitrate in methanol–trimethyl orthoformate (TMOF) to give methyl alkyl-substituted 2,5-dimethoxyphenylacetates in a good yield. A simple modification of separating method from the reacting mixture allowed us to obtain the corresponding methyl (alkylsubstituted 3,6-dioxo-1,4-cyclohexadienyl)acetates.
Isomerization of cis-2-Butene Caused by Electronically-excited Sulfur Dioxide (3B1) Adsorbed on Porous Vycor Glass
Authors: Otsuka Kiyoshi , Fukaya Masaki , Morikawa Akira 
Published: July 2006

Abstract
The cis-trans isomerization of cis-2-butene caused by electronically-excited sulfur dioxide has been studied at the gas-solid interface of porous Vycor glass. All of the quantum yields for the isomerization obtained gave values larger than ≈30. Infrared studies show that the product on the glass is the polysulfone formed through the copolymerization of sulfur dioxide and cis-2-butene. These results and the kinetic data for the isomerization can be explained satisfactorily by the proposed mechanism in which the isomerization occurs through the addition and elimination of 2-butene molecules at the terminal of the polysulfone formed on the glass; the copolymerization is initiated by an electronically-excited SO2 (3B1) state.
Determination of Absolute Configuration of Epishamixanthone, a Metabolite of Aspergillus rugulosus, by Anomalous Scattering of Light Atoms
Authors: Fukuyama Keiichi , Hamada Kensaku , Tsukihara Tomitake , Katsube Yukiteru 
Published: July 2006

Abstract
The absolute configuration of epishamixanthone has been determined from the Bijvoet differences by anomalous scattering of light atoms for Cu Kα radiation. To verify the determination, the absolute configuration of sterigmatocystin which was already determined has been examined by the same procedure. The reliability of the Bijvoet differences calculated from the structure has been estimated by means of the probability method. The errors in the measured values of the Bijvoet differences have been analysed by the normal probability plot. The accuracy of the measurement may be affected considerably by the habit of crystal. The present analysis has established that the configurations of two asymmetric carbon atoms in epishamixanthone are both R.
Studies of the Adsorbing Particle Flotation of Fe3+ and Cu2+
Authors: Kobayashi Koichi , Natori Kenichi , Kamaya Masamizu , Sasaki Tsunetaka 
Published: July 2006

Abstract
The adsorbing particle flotation of Fe2+ or Fe3+ and Cu2+ ions was studied by the combined use of bentonite (Bt) and a cationic surfactant, benzylhexadecyldimethylammonium chloride (BHDAC). Fe3+ ions were effectively floated from an aqueous solution by the use of Bt and cationic surfactant in a manner similar to the flotation by the use of sodium silicate and cationic surfactant. Most Fe2+ ions were found to be floated as Fe3+ ions, when the pH was increased by the addition of sodium hydroxide. The maximum floatability of 98% was obtained for Fe3+ under optimum conditions. The pH corresponding to the beginning of flotation of Fe3+ was influenced by the manner in which the pH of the solution was controlled. Cu2+ ions could also be floated, but less effectively than Fe3+ ions. Selective flotation of Fe3+ from the mixed solution of Fe3+ and Cu2+ was attempted and effectively achieved.
A Kinetic Study of the Ligand Exchange between Bis(acetylacetonato)-oxovanadium(IV) and Acetylacetone[14C] in Organic Solvents
Authors: Nishizawa Masato , Saito Kazuo 
Published: July 2006

Abstract
Square pyramidal [VO(acac)2] (acac, acetylacetonate) undergoes ligand exchange with Hacac[14C] in 1,2-dichloroethane (DCE) without side reactions. The rate is expressed by R=k2[complex] [Hacac], where [Hacac] stands for the concentration of free acetylacetone in enol form. The second order rate constant and activation parameters are 0.071 M−1 s−1 (M=mol dm−3) at −33 °C, ΔH\eweq=(46.7±1.7) kJ mol−1 and ΔS\eweq=(−61.9±8.4) J· mol−1 K−1. The deuterium isotope effect is kH⁄kD=1.3±0.2. It appears as if the free Hacac first interacts with the complex as unidentate and the chelation of the unidentate accompanied by proton transfer to the leaving acac− is the rate determining step. On addition of a donor solvent the exchange rate decreases, and the extent is correlated with Gutmann’s donor number. The k2, ΔH\eweq and ΔS\eweq in 0.06 M dimethyl sulfoxide (DMSO) in DCE are 0.0038 M−1 s−1 at −33 °C, (71.9±10.0) kJ mol−1, and (−4±40) J mol−1 K−1, respectively. The DMSO molecule seems to interact with the intermediate species with a unidentate Hacac and inhibits the associative rate determining step.
Synthesis of Carbamic Ester by a Reaction of Carbon Dioxide, Tetrakis(dimethylamido)titanium(IV) and Epoxide
Authors: Yoshida Yasuhiko , Inoue Shohei 
Published: July 2006

Abstract
2-Hydroxycyclohexyl dimethylcarbamate was synthesized quantitatively by a reaction of carbon dioxide, tetrakis (dimethylamido) titanium(IV) and 1,2-epoxycyclohexane.
Cyclic Peptides. IV. Synthesis of Diastereomeric Dihydro-AM-toxin I and Its Analogs
Authors: Shimohigashi Yasuyuki , Lee Sannamu , Kato Tetsuo , Izumiya Nobuo 
Published: July 2006

Abstract
Diastereomeric cyclotetradepsipeptides [l-Ala2]– and [d-Ala2]–AM-toxin I, corresponding to the hydrogenated products of AM-toxin I, were synthesized by the conventional method and their biological activities were tested. [d-Ala2]–AM-toxin I exhibits weak but recognizable necrotic activity (5–10 μg/ml) on apple leaves. [l-Ala2]–AM-toxin I is inactive even in a high concentration of 100 μ/ml. The results of NMR and ORD measurements of [d-Ala2]–AM-toxin I and [l-Tyr(Me)1, d-Ala2]–AM-toxin indicates the presence of a common conformer. The results on [l-Ala2]–AM-toxin I and [l-Tyr(Me)1, l-Ala2]–AM-toxin revealed the presence of more than two conformers, the predominant conformation differing from that of d-isomers. Difference in activity between [d-Ala2]– and [l-Ala2]–AM-toxin I can be attributed to the difference in conformation of the diastereomers.
The Substituent Effect. XII. Solvolysis of 3′- and 4′-Substituted 1-(4-Biphenylyl)ethyl Chlorides
Authors: Tsuno Yuho , Chong Wei-Yuen , Tairaka Yoshihiko , Sawada Masami , Yukawa Yasuhide 
Published: July 2006

Abstract
Rate constants of solvolysis of 3′- and 4′-substituted 1-(4-biphenylyl) ethyl chlorides were measured in 80% (v/v) aqueous acetone. The effect of substituents could be correlated excellently with the LArSR relationship.
log k⁄k0=−1.56(σ0+0.84Δ\barσR+)
The ρ and r+ values are smaller than those in the corresponding phenyl system under identical conditions (ρ=−4.95, r+=1.15). The difference of the r+ values is interpreted in terms of twisting of the two phenyls around the pivot bond in biphenyl. The same treatment has been applied successfully to other sets of reactivity data; solvolysis, protodesilylation, alkaline hydrolysis, and piperidinodebromination. The results indicate a consistently reduced effectiveness of pi-electronic transmission in biphenylyl relative to phenyl system in all reactions studied.
The Extraction of Alkali Metal Picrates into Benzene by Means of 18-Crown-6
Authors: Iwachido Tadashi , Sadakane Akira , Tôei Kyoji 
Published: July 2006

Abstract
The distribution of alkali metal picrates between water and benzene was investigated in the presence of 18-crown-6. The overall equilibrium constants, Kex, and some constituent equilibrium constants were determined. The Kex value increases, passes through a maximum (at potassium), and falls off as the size of the alkali metal cation increases.
Electronic Spectra and Charge-Transfer Absorption of Solid Anion Radical Salts of 2,3-Dicyano-p-benzoquinone and 2,3-Dichloro-5,6-dicyano-p-benzoquinone
Authors: Iida Yôichi 
Published: July 2006

Abstract
The diffuse reflection spectra were measured with solid anion radical salts of 2,3-dicyano-p-benzoquinone and 2,3-dichloro-5,6-dicyano-p-benzoquinone with rubidium and caesium cations. Strong charge-transfer transition between anion radicals was observed in the lowenergy region. The spectroscopic features of the chargetransfer absorption were discussed in terms of one-dimensional Hubbard model.
Heat of Adsorption of Ammonia on Silica-Alumina at Low Surface Coverage
Authors: Masuda Tatsuo , Taniguchi Hitofumi , Tsutsumi Kazuo , Takahashi Hiroshi 
Published: July 2006

Abstract
Heats of adsorption of ammonia on silica-alumina at very low surface coverage were measured in details. The effects of ammonia adsorption on the glass wall and on the greese were corrected. The initial heat value agreed fairly well with the heat of neutralization of NH3(G) and HCl(G). The diffusion of the gas had little effect on the value of heat of adsorption.
Nuclear Magnetic Resonance Studies of Cobalt Complexes. Cobalt-59 Nuclear Magnetic Resonance Spectrum of the Hexakis-(trimethyl phosphite)cobalt(III) Complex
Authors: Yamasaki Akira , Aoyama Takashi , Fujiwara Shizuo , Nakamura Keikichi 
Published: July 2006

Abstract
The well-resolved septet spectrum was recorded for cobalt-59 NMR of [Co(P(OCH3)3)6](BF4)3 in an acetonitrile solution. The obtained NMR parameters are: σ(Co-59)=+304 ppm (upfield from [Co(CN)6]3−), 1J(Co–P)=414 Hz, and ΔH(Co)=340 Hz.
The Reaction of ortho-Palladated Ferrocene Complexes with Olefins
Authors: Izumi Taeko , Endo Kazuyoshi , Saito Osamu , Shimizu Iwao , Maemura Mitsugi , Kasahara Akira 
Published: July 2006

Abstract
ortho-Palladation products of (dimethylaminomethyl)ferrocene and 2-pyridylferrocene were treated with various olefins under mild conditions. A variety of unusual 1,2-disubstituted ferrocene derivatives were obtained from these reactions.
Fluorescence and Dual Phosphorescence Spectra of Quinoxaline in Fluid Solution
Authors: Yamamoto Kohzaburo , Takemura Takeshi , Baba Hiroaki 
Published: July 2006

Abstract
Fluorescence and phosphorescence spectra of quinoxaline in isooctane (2,2,4-trimethylpentane) have been measured under fluid conditions. The fluorescent emission with a spectral maximum at 410 nm is assigned to the 1(n,π*)→S0 fluorescence of quinoxaline. A new phosphorescence spectrum appears in a wavelength region longer than 520 nm as the concentration of quinoxaline increases, in addition to the phosphorescence spectrum of the monomer. From the results of photostationary and transient experiments on the concentration and/or temperature dependence of phosphorescence, it has been confirmed that the phosphorescence consists of two components attributable to the monomer and the excimer.
Vibration Spectra and Rotational Isomerism of Chain Molecules. VII. 1-Chloro-, 1-Bromo-, and 1-Iodopropanes, and 1-Chloro-, 1-Bromo-, and 1-Iodobutanes
Authors: Ogawa Yoshiki , Imazeki Shuji , Yamaguchi Hiroko , Matsuura Hiroatsu , Harada Issei , Shimanouchi Takehiko 
Published: July 2006

Abstract
The Raman and infrared spectra of 1-chloro-, 1-bromo-, and 1-iodopropanes, CH3CH2CH2X (X=Cl, Br, and I), and 1-chloro-, 1-bromo-, and 1-iodobutanes, CH3CH2CH2CH2X (X=Cl, Br, and I), were measured for the gaseous, liquid, glassy, and crystalline states. The normal vibration frequencies were calculated, a consistent set of force constants explaining the frequencies of basic halogenoalkanes being assumed. The rotational isomerism was studied on the basis of the spectral observations and the normal coordinate calculations. The enthalpy differences among the rotational isomers were examined.
The Crystal Structure of the Ammonium Bromide Complex of 1,4,7,10,13,16-Hexaoxacyclooctadecane (18-Crown-6), C12H24O6·NH4Br·2H2O
Authors: Nagano Osamu , Kobayashi Akiko , Sasaki Yukiyoshi 
Published: July 2006

Abstract
Ammonium bromide forms a 1 : 1 complex with cyclic polyether “18-crown-6.” The crystals of C12H24O6·NH4Br·2H2O are orthorhombic, with the space group of Pnam and with cell constants of a=10.002(3), b=12.716(4), c=15.073(4) Å, and Z=4. The structure was solved by the conventional heavy-atom technique and refined by the full matrix least-squares method to R=0.099 for 1033 independent reflections. The 18-crown-6 has a conformation with a pseudo D3d symmetry. The ammonium cation is displaced by 1.00 Å from the mean oxygen plane of the 18-crown-6 and interacts with the nearest bromide anion. The relationship between the cation and the 18-crown-6 resembles those of the C12H24O6·RbNCS and C12H24O6·CsNCS complexes. On the difference Fourier maps, four electron-density peaks were detected at reasonable positions for the hydrogen atoms of the amonium cation.
Polarographic Behavior of Tris(acetylactonato)ruthenium(III) in Aqueous and Acetonitrile Solutions
Authors: Endo Akira , Watanabe Masayuki , Hayashi Sadayuki , Shimizu Kunio , Satô Gen P 
Published: July 2006

Abstract
In tetraethylammonium perchlorate-acetonitrile solution, [Ru(acac)3] was reversibly reduced at the dropping mercury electrode to [Ru(acac)3]− with a conditional electrode reaction rate-contsant estimated to be ca. 0.2 cm s−1 or larger. The reduced form was stable in the solution under an inert gas atmosphere. In aqueous solutions, [Ru(acac)3] was reduced reversibly when the depolarizer concentration was less than 0.07 mol m−3 at 25 °C. At higher depolarizer concentrations, [Ru(acac)3] molecules were adsorbed onto the mercury surface, and the free molecules in solution were reduced through the adsorbed layer at a smaller rate; the adsorbed layer was removed at a certain negative potential, and the reversible reduction took place normally at the bare surface. The difference between reversible half-wave potentials observed in acetonitrile and aqueous solutions was discussed in terms of solvation energies of the oxidized and reduced forms.
The Reductive Deacylation of the Knoevenagel Condensates by the Use of the Tetracarbonylhydridoferrate(0) Anion. A New Synthetic Route of Ketones from Aldehydes
Authors: Yamashita Masakazu , Watanabe Yoshihisa , Mitsudo Take-aki , Takegami Yoshinobu 
Published: July 2006

Abstract
The Knoevenagel condensates prepared from 2,4-pentanedione with aldehydes were allowed to react with the tetracarbonylhydridoferrate(0) anion in ethanol to give reductively deacylated monoketones in high yields. However, the exclusive reduction of the α,β-unsaturated double bond of the same condensates was encountered when the reaction was carried out in such a solvent as tetrahydrofuran and acetone. The Knoevenagel condensates, derived from the reaction of ethyl acetoacetate and/or ethyl benzoylacetate with aldehydes, were simply reduced even in ethanol. The reaction mechanism is briefly discussed.
Synthesis of Hindered t-Alkyl Ethers
Authors: Masada Hiromitsu , Sakajiri Tadahide 
Published: July 2006

Abstract
Di-t-butyl ether was prepared in 6–73% yields by the reactions of t-butyl halide with Ag2CO3, Ag2O, HgO, ZnO, ZnCO3, PbO2, Cu2(CO3)(OH)2, and Tl2O3 at 20–65 °C in hydrocarbons under nitrogen. Similar reactions gave seven new hindered di-t-alkyl ethers: di-t-pentyl ether, bis(1,1-dimethylbutyl) ether, bis(1-ethyl-1-methylpropyl) ether, bis(1,1-dimethylpentyl) ether, bis(1-ethyl-1-methylbutyl) ether, bis(1,1-diethylpropyl) ether, and bis(1,1-dimethylhexyl) ether. The yield of di-t-alkyl ether decreased as the t-alkyl group became bulky. A slight difference in the skeletal structure of the t-alkyl halide markedly influences the substitution. The reaction pathways are elucidated on the basis of the experimental results.
Synthetic Studies of Pyridomycin. II. Synthesis of a Model Twelve-membered Ring Compound Related to Pyridomycin
Authors: Kinoshita Mitsuhiro , Awamura Masaki 
Published: July 2006

Abstract
A prototypic compound of pyridomycin, 6-(3-hydroxypicolinoylamino)-5-methyl-8-aza-1,4-dioxacyclododecane-3,7,12-trione (11), was synthesized. 4-(Benzyloxycarbonylamino)butyric acid was coupled with t-butyl glycolate in the presence of DCCI and pyridine to afford t-butyl [4-(benzyloxycarbonylamino) butyryloxy] acetate (4). De-t-butylation of 4 followed by condensation with N-t-butoxycarbonyl-l-threonine benzyl ester by the DCCI method gave O-[{4-(benzyloxycarbonylamino)butyryloxy}acetyl]-N-t-butoxy-carbonyl-l-threonine benzyl ester (6). Deprotection of 6 followed by cyclization with Woodward’s reagent K afforded 6-(t-butoxycarbonylamino)-5-methyl-8-aza-1,4-dioxacyclododecane-3,7,12-trione (21% yield), which was transformed into the title compound 11.
The Chlorination of Hydrocarbons. XIV. The Chlorination of Vinyl Compounds
Authors: Shinoda Kiyonori 
Published: July 2006

Abstract
The competitive chlorination of various vinyl compounds was carried out in order to elucidate the effect of the structure on the addition rate of chlorine to a double bond. A linear free-energy relationship was found to exist between the reactivities in the presence of oxygen and Taft’s σ* constants. The ρ* value was calculated to be −1.20. On the other hand, the plot deviated slightly from a straight line; this shows the Taft relationship between the reactivities for the photochlorination and σ* values, known as an extra acceleration due to the hyperconjugation of the alkyl group.
14N Nuclear Quadrupole Resonance of Some Heterocyclic Compounds via Nuclear Double Resonance
Authors: Maruizumi Takuya , Hiyama Yukio , Watanabe Noriyuki , Niki Eiji 
Published: July 2006

Abstract
Using proton-nitrogen double resonance in the laboratory frame, the 14N nuclear quadrupole resonances (NQR) of 2,4(1H,3H)-pyrimidmedione[uracil], 2,3-dihydro-2-thioxo-4(1H)-pyrimidinone[2-thiouracil], 2,4(1H,3H)-pyrimidinedithione[2,4-dithiouracil], and 1,3-dihydro-2H-benzimidazole-2-thione[2-mercaptobenzimidazole] have been measured at room temperature. The NQR parameters of uracil and its sulfur-substituted compounds are interpreted by using the Townes and Dailey theory.
Inositol Derivatives. 11. Synthesis of Dianhydroinositols
Authors: Ogawa Seiichiro , Oki Shuichi , Suami Tetsuo 
Published: July 2006

Abstract
All the predicted isomers of 1,2 : 3,4- and 1,2 : 4,5-dianhydrocyclohexanehexols (5 racemates and 6 mesocompounds) were synthesized from appropriate inositol ditosylates and dimesylate by treatment with sodium methoxide.
The Reaction of Vicinal Dinitro Compounds with Tin(II) Chloride
Authors: Fukunaga Kimitoshi , Kimura Makoto 
Published: July 2006

Abstract
The reactions of vicinal dinitro compounds with tin(II) chloride have been studied. The reactions of α,β-diaryl vicinal dinitro compounds and tin(II) chloride in polar solvents gave the corresponding olefins in good yields. The aliphatic vicinal dinitro compounds did not react with tin(II) chloride under the same reaction conditions. A reaction mechanism of elimination involving a radical anion intermediate has been proposed.
The X-Ray Structure Determination of Heptaethylene Glycol–Sr(SCN)2
Authors: Ohmoto Hideyo , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami , Yanagida Shozo , Okahara Mitsuo 
Published: July 2006

Abstract
The crystal structure of heptaethylene glycol–Sr(SCN)2 has been determined by X-ray diffraction. The Sr ion is coordinated by eight oxygen atoms arising from the heptaethylene glycol moiety and a nitrogen atom from one of SCN groups. The coordination polyhedron is irregular, Sr–O distances ranging from 2.56 to 2.73 Å.
The Extraction Spectrophotometric Determination of Cobalt(II) with 4-(2-Thiazolylazo)resorcinol and Zephiramin
Authors: Ueda Kazumasa 
Published: July 2006

Abstract
The cobalt(II)–4-(2-thiazolylazo)resorcinol chelate anion is quantitatively extracted into chloroform with a cation of zephiramin as an ion-pair complex. This process was applied to the spectrophotometric determination of cobalt. The effective separation and the sensitive determination for a trace amount of cobalt could be confirmed even in the presence of high concentrations of masking agents.
The Reaction of 3,5-Diphenyl-1,2-dithiolium Perchlorate with Active Methylenes
Authors: Shibuya Isao 
Published: July 2006

Abstract
3,5-Diphenyl-1,2-dithiolium perchlorate (1) was synthesized in a new, convenient way, and the reaction of 1 with several active methylene compounds was studied. The compounds possessing no less than one ester group gave novel products, 3-substituted 4,6-diphenyl-2H-thiopyran-2-ones, while those possessing a carbamoyl group gave 3-substituted 2-hydroxy-4,6-diphenylpyridines or 3-cyano-1,4,6-triphenyl-2-pyridone. Malononitrile, however, gave 1-mercapto-1,3-diphenyl-4,4-dicyanobutadiene (10). On treatment with methyl iodide or p-chlorobenzyl chloride, 10 gave 1-methylthio- or 1-(p-chlorobenzylthio)-1,3-diphenyl-4,4-dicy-anobutadiene, and also led to bis(1,3-diphenyl-4,4-dicyanobutadienyl) disulfide on treatment with hydrogen peroxide.
Cobalt Metallocycles. VII. η5-Cyclopentadienyl-η4-iminocyclopentadienecobalt Complexes from a Reaction of Cobaltacyclopentadienes with Isocyanides
Authors: Yamazaki Hiroshi , Wakatsuki Yasuo 
Published: July 2006

Abstract
The reaction of (η5-cyclopentadienyl)(triphenylphosphine) cobaltacyclopentadienes with isocyanides gives η5-cyclopentadienyl-η4-iminocyclopentadienecobalt complexes in good yields. Treatment of the product with HBF4 or CH3I yields the corresponding aminocobalticinium salt.
An ESR Study on the Working States of a Pure V2O5 Crystal under the CO-oxidation
Authors: Kera Yoshiya , Kuwata Keiji 
Published: July 2006

Abstract
The V2O5 crystal, prepared from the pure V2O5 powder by a zone-melting method in the air, did not show any ESR signal. When the crystal came into contact with a mixture of CO and O2 ((CO/O2)≥4), an ESR spectrum with the hfs of 15-lines (g⁄⁄=1.932, g⊥=1.978; 〈g〉=1.963), which has been previously ascribed to an oxygen defect, was found at the beginning, but after prolonged contact a sharp spectrum (〈g〉=1.954) appeared. The intensity of the hf-lines was constant but that of the sharp spectrum increased with the contact time. The g-value and line shape of both spectra did not change with the contact time. The same spectra were also found in the crystal grown under a mixture of CO and O2. On the thermal decomposition of pure NH4VO3in vacuo a similar spectrum with a sharp line was found. The g-value became lower in the sample reduced further by SO2 after the thermal decomposition. With reference to the data of TGA, DTA, magnetic susceptibility (χmol), and X-ray analysis of the vanadium oxides, the sharp spectrum was ascribed to a lower oxide or oxide state such as V3O7. Based on the ESR results, the working state of pure V2O5 crystal under CO-oxidation and its catalytic property are discussed.