bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Reduction of gem-Dibromocyclopropanes by Means of Chromium(II) Acetate or Potassium Pentacyanocobaltate
Authors: Shirafuji Tamio , Oshima Koichiro , Yamamoto Yasusi , Nozaki Hitosi 
Published: July 2006

Abstract
The reduction of gem-dibromocyclopropane(I) with CrII acetate in DMSO gives monobromocyclopropanes (II and III) exclusively, whereas the same components in aq DMF afford cyclopropyl acetates(IV and V) as the major products in addition to II and III. A similar substitution on cyclopropane carbon is observed in the reduction of I with K3Co(CN)5 in DMSO, furnishing cyclopropyl cyanides (IX and X) mainly. The stereochemistry of II, III, IV, and V is determined by the NMR coupling constants and chemical shifts, and that of IX and X, by transformation to the corresponding cyclopropyl methyl ketones derived from cyclopropanecarboxylic acids of known configurations. The reaction of II or III with K3Co(CN)5 is also described.
The Structure of Petasitolone, a New Constituent of Petasites japonicus Maxim
Authors: Naya Keizo , Yoshimura Fumio , Takagi Ichiro 
Published: July 2006

Abstract
Petasitolone(I), a new sesquiterpene isolated from Petasites japonicus Maxim, has been shown to be 8-oxo-11-hydroxy-Δ6(7)-eremophilene by a physico-chemical method, and synthesized from the known fukinone(VI).
An ESR Study of NO2 Adsorbed on Silica Gel Surfaces
Authors: Iwaizumi Masamoto , Kubota Shozo , Isobe Taro 
Published: July 2006

Abstract
NO2 adsorbed on silica-gel surfaces shows temperature-dependent ESR spectra, which can be explained by assuming a restricted rotation of the NO2 molecule, where the preferred axis is the O–O direction. It is concluded from this observation that a hydrogen-bond force between the oxygen of NO2 and OH groups on the silica-gel surfaces plays a part in the NO2-silica-gel interaction. It is also estimated, from the observed hyperfme tensor, that the ONO angle may become slightly smaller when NO2 is adsorbed onto the silica-gel surface from the gas phase.
The Catalytic Activity and Selectivity of Acidic Metal Salt Catalysts for n-Butene Isomerization
Authors: Misono Makoto , Yoneda Yukio 
Published: July 2006

Abstract
Double-bond isomerization of n-butenes over several supported acidic metal salts such as metal sulfates, perchlorates and phosphates including free acids has been investigated at 60°C with the butene pressure of 14 cmHg. The activity and the selectivity of cis-trans isomerization over double-bond migration increased monotonously, as the acid strength of catalysts increased. Acid strength, activity and selectivity of metal salt catalysts increased with the electronegativity of metal ion where free acids were the most strongly acidic and active catalysts (H+&gt;Al3+&gt;Ni2+&gt;Mg2+&gt;Na+), and for a given metal ion they increased with the acid strength of the conjugated acid (ClO4−&gt;SO42−PO43−CH3COO−). The activity and selectivity were explained on the basis of a sec-hutyl carbonium ion mechanism which appears more concerted over weak acids. The active sites for the reaction were suggested to be protonic acid sites closely connected to acid radical.
Acidity Constants of Phenanthrylamines in the Ground, Excited Singlet, and Triplet States
Authors: Tsutsumi Kinzo , Aoki Kazuko , Shizuka Haruo , Morita Toshifumi 
Published: July 2006

Abstract
Measurements of the acidity constants in the ground (pKa(S0)), the lowest excited singlet (pKa(S1)), and triplet states (pKa(T1)) for 2-, 3-, 4-, and 9-phenanthrylamines have been carried out by spectrophotometry. The pKa values obtained were in the order of pKa(S0)&gt;pKa(T1)&gt;pKa(S1). The absorption and emission spectra of the phenanthrylamines were compared with the results of the calculations by means of the semi-empirical SCF-MO-CI method. A linear relationship between the pKa values and the net charge (or charge densities) in the ground and excited states was obtained both experimentally and theoretically.
Adsorption and Decomposition of Formic Acid Adsorbed on Pyrolyzed Polyacrylonitrile
Authors: Kubokawa Yutaka , Miyata Hisashi , Uegaki Yoshihiko 
Published: July 2006

Abstract
Infrared spectra of various pyrolyzed polyacrylonitrile and of deuterated formic acids (HCOOD, DCOOH, and DCOOD) adsorbed on it were investigated. The effect of pyrolysis temperature upon the decomposition products of formic acid adsorbed on the polymer was studied. It was found that parallelism exists between the concentration of the conjugated nitrile group and the percentage of the decomposition of formic acid adsorbed, leading to the conclusion that the active sites for the decomposition reaction are associated with the conjugated nitrile group in the case of polyacrylonitrile pyrolyzed below 300°C. On the other hand, there was a close correlation between the activity for decomposition and the number of free spins in the polymer pyrolyzed above 350°C.
Vibration Spectra and Molecular Structures of n-Butyronitrile, β-Chloropropiononitrile, and β-Bromopropiononitrile
Authors: Fujiyama Tsunetake 
Published: July 2006

Abstract
Infrared and Raman spectra of XCH2CH2CN-type molecules (X=CH3, Cl, and Br) are studied. From the spectral analysis, it is concluded that trans and gauche isomers coexist in the liquid phase, the gauche being more stable. It is also shown that these molecule take gauche configurations in the crystalline phase.
Stability and Extractability of Zinc(II) Thiocyanate Complexes in Several Solvent Extraction Systems
Authors: Moriya Hiromitsu , Sekine Tatsuya 
Published: July 2006

Abstract
The formation and extraction equilibria of zinc(II) complexes with thiocyanate ions have been determined at 25°C. Zinc(II) ions in 1 m sodium perchlorate constant ionic media containing thiocyanate ions at various concentrations have been extracted into chloroform containing β-isopropyltropolone (IPT), into hexane containing trioctylphosphine oxide (TOPO), or into methyl isobutyl ketone (MIBK). The stability constants of the zinc(II) thiocyanate complexes in the aqueous phase were first determined from the decrease in the IPT chelate extraction, and then the distribution constants for the zinc(II) thiocyanate complexes into the latter two solvents were determined. The results were explained by saying that (i) zinc(II) forms the first (logβ1=0.56), second (logβ2=1.32), and the third (logβ3=1.18) complexes in the above aqueous phase, (ii) TOPO in hexane extracts the second complex as an adduct in the Zn(SCN)2(TOPO)2 form, (iii) MIBK extracts both the second and the third complexes, and (iv) the addition of sodium perchlorate causes a salting-in effect in the lower-ligand-concentration region. Some discussion was made of the dissociation of ion-pairs in the organic phase.
Four Radical Species Produced Photochemically in the Solid Mixture of Acridine and Acridan
Authors: Niizuma Shigeya , Kokubun Hiroshi , Koizumi Masao 
Published: July 2006

Abstract
It has been established from measurement of the fusion curve that a 1 : 1 complex of acridine and acridan is formed in the solid state. The complex has an absorption band at 400–500 nm and is considered to be of C-T character although hydrogen bonding plays a role in complexing. Excitation of this complex gives rise to four radical species which display the corresponding characteristic ESR signals a, b, c, and d. The line width of a (α) and the line separations of b, c, d (β, γ, δ) are α=18.0±3.5, β=112±2, γ=137±5, δ=212±6 gauss. Studies on the dependence of the relative intensities of a, b, c, and d upon the acridine-acridan ratio and upon the length of irradiation have led to the conclusion that a and b are due to C- and N-radicals (the latter, triplet with separation of 44 gauss) and c and d are two kinds of radical pair. Detection of ΔM=±2 transition at 1670 gauss (with 9337.4 MHz) also confirmed the above assignment of c and d. It is likely that the mutual transformation occurs only during irradiation. It is concluded that C-radical is more stable than N-radical in agreement with the result in fluid state. An interesting decay feature of signal a was found and was given a plausible interpretation.
Electron-Transfer Reactions of Multidentate-ligand Cobalt(III) Complexes. III. The Reductions of Several Chloro- and Bromo(nitrilopolycarboxylato)cobaltate(III) Ions by Iron(II)
Authors: Kurimura Yoshimi , Meguro Ikuko , Ohashi Kousaburo 
Published: July 2006

Abstract
The reductions of chloro- and bromo(ethylenediaminetriacetatoacetic acid)cobaltate(III), chloro- and bromo (N-hydroxy ethy lethy lenediamine-N,N′, N′-triacetato)cobaltate (III), and dichloro(ethylenediaminediacetato) cobaltate(III) ions by iron(II) in perchloric acid solutions obey the second-order rate expression: –d-[Co(III)]/dt=kc[Co(III)][Fe2+]. The second-order rate constants, kc, and activation parameters for these reactions were determined spectrophotometrically. For the cases of all the Co(III) complexes investigated, an increase in the rate constant with the hydrogen-ion concentration at a constant ionic strength is expressed by: logkc=logk0+A[H+], where k0 and A are constants for the given complex at a constant ionic strength and temperature. The hydrogen-ion dependence can be explained by the difference in the degree of stabilization of the Co(III) anion between that by hydrogen ions and that by sodium ions.
Spectroscopic Studies of Polynuclear Complexes. III. Characteristics of Some μ-Peroxoammine Cobalt(III) Complexes.
Authors: Sasaki Yoichi , Fujita Junnosuke , Saito Kazuo 
Published: July 2006

Abstract
The spectroscopic and chemical properties of various μ-peroxo and μ-superoxo cobalt(III) complexes containing several kinds of polyamine including optically active l-propylenediamine (l-pn) have been studied. The single bridged μ-peroxo complexes have strong absorption peaks at ca. 300 nm, whereas the double-bridged μ-peroxo-μ-amido and μ-peroxo-μ-hydroxo complexes have peaks at ca. 350 nm. The μ-superoxo complexes have two absorption peaks in the visible region at ca. 700 and 480 nm. The former is remarkably stronger for singlebridged species, but both are of almost equal strength for double bridged species. The complexes [LNH3Co(μ-O2(2−))CoNH3L]4+ (L; 2en (ethylenediamine), 2l-pn, and trien(triethylenetetramine)) are spontaneously converted into [LCo(μ-O2(2−), OH)CoL]3+ in water at room temperature. The en ligands in [(dien)(en)Co(μO2(2−))Co(en)(dien)]4+ (dien; diethylenetriamine) are replaced by l-pn in a few days in aqueous solutions containing an excess of l-pn. The absolute configuration of [(l-pn)2Co(μ-O2(2−), OH) Co(l-pn)2]3+ is assigned to be ΔΔ on the basis of circular dichroism spectrum.
Syntheses of (3S, 4R, 15S)-4,15-Dimethyl-1,5-dioxa-3-(3′-formamidosalicylamido)-cyclopentadecane-2,6-dione and Its (15R)-Epimer, New Antimycin Analogs
Authors: Kinoshita Mitsuhiro , Ishii Keitaro , Umezawa Sumio 
Published: July 2006

Abstract
A new type of antimycin analogs, (3S, 4R, 15S)-4,15-dimethyl-l,5-dioxa-3-(3′-formamidosalicylamido)-cyclopentadecane-2,6-dione (10a) and its (15R)-epimer (10b) have been synthesized. The epimeric fifteenmembered amino-dilactone moieties in 10a and 10b were synthesized from a masked l-threonine and t-butyl Dl-10-hydroxyundecanoate. Each of the separated epimeric amino-dilactones was N-acylated with O-benzyl-3-nitrosalicylic acid N-hydroxysuccinimide ester. Hydrogenation followed by N-formylation afforded the anti-fungal substances,10a and 10b. The 10-C-configurations of 10a and 10b were determined as “S” and “R”, respectively. The (15S)-epimer (10a) showed apparently stronger antifungal activity against Piricularia oryzae than that of the (15R)-epimer (10b).
The Reaction of Nitriles under High Pressure, I. The Formation of Triphenyl-1,3,5-triazine via the Equilibrium among Benzonitrile, Alcohols, and Benziminoethers
Authors: Kurabayashi Masahiro , Yanagiya Koshin , Yasumoto Masahiko 
Published: July 2006

Abstract
Benziminoethers were formed from benzonitrile and alcohols to the equilibrium extent, and then 3 mol of benziminoethers were reacted with each other to afford triphenyl-1,3,5-triazine at 2–10kbar and 100–120°C. The equilibrium shifted toward benziminoether with an increase in the pressure. The equilibrium constant decreased progressively in the order of methanol&gt;ethanol≈n-propanol≈n-butanol&gt;isopropanol≈sec-butanol, which accords with the increasing number of substituents on the α-position of the alcohols. The formation of triphenyl-1,3,5-triazine obeyed the second-order reaction mechanism and was also retarded in the same order. The reaction was found to proceed in the following manner: Benziminoethers produced by the addition of alcohols to benzonitrile dimerize through a rate-determining step and then trimerized into triphenyl-1,3,5-triazine. The apparent activation volume of the formation of triphenyl-1,3,5-triazine amounted to −31 cm3 mol−1 at 110°C when methanol was used as the alcohol. The accelerating effect of the pressure on the formation of triphenyl-1,3,5-triazine is concluded to be mainly caused by the shift of equilibrium toward benziminoether. Three isomers of cyanopyridine were converted in good yields into the corresponding triazines under high pressure.
The Preparation of 9-Ethynylanthracene and 9-Ethynyltriptycene and Their Oxidative Coupling
Authors: Akiyama Shuzo , Ogura Fumio , Nakagawa Masazumi 
Published: July 2006

Abstract
The formation of 9,10-dichloroanthracene by reaction of 9-acetylanthracene with phosphorus pentachloride is described. 9-Ethynylanthracene and 9-ethynyltriptycene have been prepared according to Köbrich’s method. The resulting ethynyl compounds have been converted to the corresponding di-ynes using the Eglinton’s oxidative coupling reaction.
Charge Migration through Sigma Bonds in a Fragment Ion from 5,5′-Divaleryl-2,2′-spirobiindan under Electron Impact
Authors: Tatematsu Akira , Naga Shinobu , Sakurai Hiroshi , Goto Toshio , Nakata Hisao 
Published: July 2006

Abstract
In order to examine the nature of charge and radical electron migration in mass spectral fragment ions, 5,5′-di-n-valeryl-2,2′-spirobiindan (3) was prepared and its mass spectrum was measured. The successive loss of two propylene molecules from the molecular ion to give peaks at m⁄e 346 (b) and 304 (c) was clearly indicated by observing appropriate metastable ion peaks. As the radical electron is one of the prerequisites for these fragmentations to occur, the results demonstrate that the charge and radical electron can migrate through sigma bonds in fragment ion b, since the two n-valerophenyl groups cannot be brought into close proximity even with C–C bond fission of the spiro ring. While the strongest peak at m⁄e 331 (a) is ascribable to the ordinary α-fission of the carbonyl group in 3, a moderately intense peak at m⁄e 289 (d) can adequately be explicable by the similar α-fission of the carbonyl group in ion b, the process of which again involves radical electron migration prior to fragmentation.
ESR and Optical Studies on the EDA Complexes of Di-t-butyl-N-oxide Radical
Authors: Murata Yoshifumi , Mataga Noboru 
Published: July 2006

Abstract
It has been confirmed that di-t-butyl-N-oxide (DTBNO) forms EDA complexes with various electron acceptors, and the resulting complexes show CT (charge transfer) absorption bands. Wave-numbers of the CT bands agreed satisfactorily with theory. Charge distributions in the EDA complexes of DTBNO, including hydrogen bonded complexes with proton donors, have been investigated by means of ESR. From the effect of the EDA complex formation upon the hyperfine coupling constant of 14N of DTBNO, contribution of electrostatic forces to complex formation has been demonstrated. However, in the case of complexes with strong acceptors such as tetracyanoethylene, the values of the hyperfine coupling constant have indicated a significant contribution of CT interaction to complex formation.
Molecular Structure of Diacetylene as Studied by Gas Electron Diffraction
Authors: Tanimoto Mitsutoshi , Kuchitsu Kozo , Morino Yonezo 
Published: July 2006

Abstract
The molecular structure of diacetylene has been studied by gas electron diffraction. Thermal-average bond distances are determined to be: rg(C–C)=1.3837±0.0019 Å, rg(C≡C)=1.2176±0.0014 Å, and rg(C–H)=1.0935±0.010 Å. The C–C single bond is about 0.007 Å shorter than that in cyanogen, while the C≡C triple bond is about 0.005 Å longer than that in acetylene. The observed mean amplitudes are slightly larger than the parallel amplitudes based on harmonic calculations. A suggestion has been made to account for the discrepancies by the use of empirical constants representing the interaction between bending and bond-stretching vibrations, which makes the bond distances slightly longer, on the average, in a momentary bent structure than in a linear structure. This interaction also seems to account for a slight difference between the rotational constant B0 estimated from the above rg distances and those derived from spectroscopic experiments.
N-Benzenesulphonyl β-Alanine as a Masking Agent for Hg(II)
Authors: Ghosh Nripendra Nath , Bhattacharyya Anjali 
Published: July 2006

Abstract
N-Benzenesulphonyl glycine and N-benzenesulphonyl α-alanine form water soluble complexes with Hg(II), Cu(II), and Ag(I). But N-benzenesulphonyl β-alanine (RbβH2) gives only stable complex ion Hg(Rbβ)22−, showing that RbβH2 is a highly selective masking agent for Hg(II). Utilising this masking property, methods for detection and determination of Hg(II) have been developed. RbβH2 reacts with Hg(II) at pH≈8, yielding the ion Hg(Rbβ)22− and on subsequent treatment with KI, two equivalents of alkali are liberated. On titrating the alkali liberated with a standard acid, the amount of Hg(II) may be calculated. Interferences due to diverse ions have been studied; Br− and I− interfere. The spot test of Hg(II) based on the same principle has been developed and it appears to be specific under specified condition. The limit of identification is 0.5 μg with a dilution limit of 1:100000.
The Characterization of CdFe(CO)4 and HgFe(CO)4 by Infrared and Mössbauer Spectroscopy and X-Ray Diffractometry
Authors: Takano Tetsuo , Sasaki Yukiyoshi 
Published: July 2006

Abstract
Two compounds, MFe(CO)4 (M=Cd or Hg), were investigated by the use of infrared and Mössbauer spectroscopy and X-ray diffractometry. The infrared data suggested that the M atoms link Fe(CO)4 units to form infinite zig-zag chains; these metal atoms are attached to the iron atom at cis-positions and form an octahedron with four carbonyl groups. The Mössbauer spectra and infrared data indicate that the Cd–Fe and Hg–Fe bonds are not ionic but covalent, that they are as strong as C–Fe bonds in iron carbonyls. The isomorphism of the two compounds was confirmed by the X-ray diffractometry.
The Syntheses and Properties of Some 2,4-Dimethyl-1,5-benzodiazepinium Halogenometalates
Authors: Ouchi Akira , Takeuchi Toshio , Nakatani Mitsuhisa , Takahashi Yoshiaki 
Published: July 2006

Abstract
When 2,4-dimethyl-1,5-benzodiazepinium halide was reacted with a metal halide in ethanolic media, crystalline products, M(C11H13N2)xXy (where X=Br, Cl; M=Co(II), Mn(II), Zn(II), Cd(II), Sb(III) (chloride), Cu(II) (chloride), and Cu(I) (bromide)), were obtained. They are all new compounds. Their electronic and infrared spectra resemble those of the sarting chloride or bromide. The infrared band at about 1639 cm−1 of the chloride shifts to the lower-wave-number side when it is turned into a halogenometalate. On the other hand, the characteristic ν(M–X) bands were found in the far-infrared spectra of the halogenometalates, These compounds are likely to be ionic compounds consisting of the halogenometalato anion and the 2,4-dimethyl-1,5-benzodiazepinium cation.
The Dehydration of N-Benzyloxy and N-Hydroxymaleamic Acid and the Isomerization of N-Benzyloxyisomaleimide
Authors: Narita Mitsuaki , Akiyama Masayasu , Okawara Makoto 
Published: July 2006

Abstract
The dehydration of N-benzyloxy and N-hydroxymaleamic acids and the isomerization of N-benzyloxyisomaleimide were carried out under various conditions to obtain N-benzyloxyisomaleimide, N-hydroxyisomaleimide, and N-benzyloxymaleimide. N-substituents, such as benzyloxy, hydroxy, and acetoxy groups, depress the reactivity of nitrogen electronically and facilitate the formation of isomaleimides in the dehydration of N-substituted maleamic acids. The thermal isomerization of N-benzyloxyisomaleimide to the maleimide has been successful only in N,N-dimethylformamide. Further the conversion of isomaleimide to maleimide was performed via the addition of hydrogen bromide to isomaleimide followed by isomerization and dehydrobromination.
The Mechanism of Silver Perchlorate Catalyzed Solvolysis Reaction of 2-Chlorocyclohexanone-1-14C
Authors: Masuike Taketoshi , Furukawa Naomichi , Oae Shigeru 
Published: July 2006

Abstract
Silver perchlorate assisted solvolysis of 2-chlorocyclohexanone-1-14C in ethanol-water solution gives 2-ethoxycyclohexanone-x-14C. Successive degradation of the product reveals that the 14C activity is distributed in both the carbonyl carbon and the α-carbon of ethoxyketone. The 14C distribution pattern suggests that a part of the reaction proceeds via an epoxide intermediate which is formed by the initial attack of ethanol on the carbonyl carbon, followed by the migration of carbonyl oxygen to the α-carbon of 2-chlorocyclohexanone.
Tracer Study of the Reactions of Diphenyl Sulfone and Diphenyl Sulfoxide with Diphenyl Disulfide
Authors: Oae Shigeru , Tsuchida Yoshiyuki , Nakai Mamoru 
Published: July 2006

Abstract
Diphenyl sulfoxide and diphenyl sulfone were found to react with diphenyl disulfide at elevated temperatures, forming in both reactions diphenyl sulfide and sulfur dioxide. On the basis of 35S and 14C tracer experiments, these reactions were found to proceed through quite different mechanistic routes, viz., S–O bond fission in the case of sulfoxide and C–S bond fission in sulfone. The reactions apparently proceed through the attack of the thiyl radical on the sulfoxide and sulfone functions. Further mechanistic details of the reactions are discussed.
Studies of Phosphorylation. V. The Synthesis of Inosine-5′-thiophosphates
Authors: Haga Kazuko , Kainosho Masatsune , Yoshikawa Masaharu 
Published: July 2006

Abstract
Two isomers of inosine-5′-thiophosphates, inosine-5′-phosphorothionate and 5′-deoxy-5′-thioinosine-5′-phosphorothioate, were synthesized by the direct phosphorylation of inosine with phosphorus thiochloride, and by the treatment of 5′-deoxy-5′-iodoinosine with trisodium phosphorothioate, respectively. The structure of the thiophosphate residues was identified by means of 31P NMR. The flavoring activities of these thiophosphates were measured as the synergistic strength with monosodium glutamate; it was found that the strength of each compound was lower than that of inosine-5′-phosphate.
Studies on Microbial Utilization of Petroleum. I. Separation and Characterization of Carotenoids Produced by a Species of Brevibacterium in Hydrocarbon Media
Authors: Sakurai Hyoichiro , Kato Kenji , Sakai Toshio , Masuda Yoshiro , Kuriyama Tohoru 
Published: July 2006

Abstract
Ten pigment fractions were separated from a Brevibacterium sp. KY-4313 in hydrocarbon fermentation. The pigments were extracted from cell with a mixture of petroleum ether and acetone, and purified by column and thin-layer chromatography. The principal carotenoid of this organism was identified as canthaxanthin (4,4′-dioxo-β-carotene) by using visible, IR, NMR, and mass spectra of the pigment. Three other pigments were characterized as β-carotene, echinenone (4-oxo-β-carotene), and 15-cis-4,4′-dioxo-β-carotene. Three carboxylic carotenoids and three other carotenoids were also separated but their structures were left unidentified. Quantitation of the pigments showed that canthaxanthin represented 53% and its cis-isomer 20% of the pigments separated from extracts. β-Carotene derivatives comprise more than 80% of the pigments. Canthaxanthin and echinenone have not previously been reported as bacterial pigments in hydrocarbon fermentation.