bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Molecular Orbital Study of the Partial Reactivity of the Hydrogen of Aliphatic Compounds in the Hydrogen-abstraction Reaction by the Hydroxyl Radical
Authors: Shinohara Hiroyuki , Imamura Akira , Masuda Takahiro , Kondo Masaharu 
Published: July 2006

Abstract
The energy required to stretch a C–H bond of alkanes by 0.5 Å from an equilibrium bond length was calculated by the INDO method, and it was found that this energy has a relation with the delocalizability, DrR, of hydrogen atoms in alkanes, and with the activation energy for the hydrogen-abstraction reaction of the methyl radical from alkanes. The reactivities of hydrogen atoms in aliphatic alcohols and carboxylate ions, as defined by this energy were found to correlate with the partial reactivities of hydrogen atoms, just as was proposed by Anbar et al., i.e., the rate constants for the hydrogen-abstraction reaction of aliphatic compounds with hydroxyl radicals can be well explained by a summation of the partial reactivities assigned to primary, secondary, and tertiary hydrogen atoms bound to α- or β- (for γ-CH and δ-CH the same value as for β-CH was used) carbon atoms.
Study of the Chemisorption and Hydrogenation of Propylene on Platinum by Temperature-Programmed Desorption
Authors: Tsuchiya Susumu , Nakamura Masami , Yoshioka Norihiko 
Published: July 2006

Abstract
The temperature-programmed desorption (TPD) chromatograms of propylene from platinum black comprised four peaks: A, B, C, and D, with peak maxima at about 260, 380, 570, and higher than 720 K respectively. Peaks A and B were identified as the mixtures of propylene and propane. Peaks C and D were methane formed from chemisorbed propylene by decomposition as the temperature was raised during the subsequent TPD. The reactivities of various types of chemisorbed hydrogen previously detected by TPD were also investigated with regard to the hydrogenation of propylene. Two types of chemisorbed hydrogen, presumed to be present on the surface in the form of hydrogen atoms chemisorbed on top of platinum atoms and in the bridge form of molecular hydrogen, were found to react with propylene.
The Crystal Structure of a Stable Benzocyclobutene. II. 2,7-Di-t-butyl-10,10,11,11-tetracyano-4,5,9,12-tetraphenyltetracyclo-[6.4.0.03,6 .09,12]dodeca-1(8),2,4,6-tetraene
Authors: Tsukada Harumichi , Shimanouchi Hirotaka , Sasada Yoshio 
Published: July 2006

Abstract
As the first step in the investigation of the reaction mechanism of a benzocyclobutene derivatives, the title compound has been determined by the X-ray diffraction method. The crystals are monoclinic; space group P21/n; a=28.117(3), b=11.148(1), c=13.167(1) Å, and β=97.26(1)°. The asymmetric unit contains one molecule of the title compound and acetonitrile. The structure was solved by the direct method and refined by the block-diagonal least-squares method to a final R factor of 0.088 for 5456 observed reflections. The molecular framework consists of a planar ten-membered ring from benzodicyclobutene and a slightly folded four-membered ring formed by the addition of tetracyanoethylene (TCNE). Calculation has been undertaken for the non-bonded interaction energy of possible modes of approach between benzodicyclobutene and TCNE. The results are in qualitative agreement with the folding of the four-membered ring.
Metachromasy. V. The Effect of the Chain Length of Polyphosphate on the Metachromatic Behavior of Crystal Violet and Trypaflavine with Emphasis on the Binding Curve and the Spectra of Bound Dyes
Authors: Takatsuki Mineo , Yamaoka Kiwamu 
Published: July 2006

Abstract
Absorption spectra of two metachromatic dyes, Crystal Violet, CV, and Trypaflavine, TF, were measured in the presence of three sodium polyphosphates, NaPP, of different chain lengths. The optical titrations of these systems were performed at the phosphate residue-to-dye ratios, P/D, between 0 : 1 and about 1 : 1, where isosbestic points are present in the absorption spectra. The apparent molar absorption coefficients of the two dyes in each system changed sigmoidally with the increase in P/D. The extended principal component analysis was applied to the observed spectra of each dye–NaPP system in order to determine both the equilibrium constant for the binding reaction between the dye and the polymer and the pure spectra of the bound dyes. An empirical parameter α was introduced into the expression for the equilibrium constant, K=[complex]/[free dye] [unoccupied binding site]α, to reproduce the sigmoidal titration curve (α&gt;1). The amount of the bound CV and TF increased with the increase in the chain length of NaPP at a given P/D, although the pure spectra of those bound dyes were independent of the chain length for low P/D values. The binding behavior of those dyes for high P/D values was also discussed by comparing the previous data with the binding curves calculated in this work.
Bridges in Polynuclear Complexes. I. The Reaction and Reaction Products of μ(NH2,O2) Dicobalt Complexes with Nitrites
Authors: Kubo Shigekazu , Shibahara Takashi , Mori Masayasu 
Published: July 2006

Abstract
The IR spectroscopy of the μ-amido-μ-nitro complex, [(NH2,N02){Co(NH3)4}2]Cl4·2H2O obtained from normal and 18O-labeled [(NH2,O2){Co(NH3)4}2](NO3)4 has revealed that the O atom in the Co–N–O–Co chain comes from the O2 bridge of the starting complex, whereas the O atom attached to the N atom from outside the chain comes from the nitrite used in the bridge conversion, μO2→μNO2. A reaction mechanism involving N2O3 as the reacting species is proposed. The reaction of [(NH2,O2){Co(NH3)4}2]X3 with the nitrite in neutral solution gave a non-electrolytic μ-hyperoxo dicobalt complex, [(NH2,O2)Co2(NH3)4(NO2)4](I). Treatment of I with perchloric acid gave a triple-bridged complex, [(NH2,NO2,O2)Co2(NH3)4(NO2)2]+, which reproduces I when treated with sodium nitrite.
Dual Fluorescence and Excited-state Double Proton Transfer in the Dimer of 3,5-Dialkyl-4-hydroxybenzylidenemalononitrile
Authors: Itoh Michiya , Inoue Kenji , Kuzuhara Tomoko , Kusui Tomoko 
Published: July 2006

Abstract
Dual fluorescence of the dimer of 3,5-dialkyl-4-hydroxybenzylidenemalononitrile (HO-BMN) was investigated by steady-state and nanosecond fluorescence spectroscopies. The dimerization of the compounds in 3-methylpentane (MP) solution was confirmed by concentration dependence of absorption and fluorescence spectra at low temperature (&lt;150 K). While the MP solutions of the compounds are almost non-fluorescent at room temperature, the dimer exhibits a short-lived fluorescence (τ=4–9 ns) at 450–520 nm and a long-lived fluorescence (τ=21–34 ns) at 490–550 nm. The short-lived fluorescence was ascribed to a sandwich type dimer (D*) with a center of symmetry. An orientational relaxation leading to the double proton transfer reaction seems to occur in the excited state of the dimer. The long-lived fluorescence in the dimer was tentatively ascribed to the excited species (T*) generated by the double proton transfer reaction in D*. The excited-state proton transfer is discussed in terms of the effect of deuterium substitution of a 4-hydroxyl hydrogen upon fluorescence lifetimes of the dimer.
The Solvent Extraction of Bivalent Metal Picrates by 15-Crown-5, 18-Crown-6, and Dibenzo-18-crown-6
Authors: Takeda Yasuyuki , Kat\={o} Hisanori 
Published: July 2006

Abstract
The overall extraction equilibrium constants (Kex) for the 1:1:2 complexes of 15-crown-5 (15C5), 18-crown-6 (18C6), and dibenzo-18-crown-6 (DB18C6) with several bivalent metal picrates between benzene and water have been determined at 25 °C. The Kex sequences of the bivalent metal ions with 15C5, 18C6, and DB18C6 are Pb2+&gt;Sr2+&gt;Ba2+&gt;Ca2+, Pb2+&gt;&gt;Ba2+=Sr2+&gt;Hg2+&gt;Ca2+, and Pb2+&gt;Hg2+&gt;Sr2+&gt;Ca2+ respectively. To clarify the role of the crown ether in the extraction process, the three constituent equilibria have been investigated: the stability and the extractability of the bivalent metal ion-crown ether complex, and the distribution coefficient of the crown ether. The extractability of the bivalent metal ion-crown ether complex about the same bivalent metal ion increases with increasing size of the crown ether, and appears to be dependent on the chemical nature of the bivalent metal ion trapped in the cavity of the crown ether.
Conditions of the Formation of Rare Earth Phosphates and the Colors of Their Powders
Authors: Tsuhako Mitsutomo , Ikeuchi Sayuri , Matsuo Tsuneo , Motooka Itaru , Kobayashi Masamitsu 
Published: July 2006

Abstract
Rare earth oxides, such as La2O3, Pr6O11, Nd2O3, and Sm2O3, can react with phosphoric acid to give four kinds of rare earth phosphates (orthophosphates LnPO4·0.5H2O and LnPO4, catena-polyphosphates Ln(PO3)3 and ultraphosphates LnP5O14), while in the reaction of CeO2 with phosphoric acid there are formed five kinds of phosphates (orthophosphate CePO4, pyrophosphate CeP2O7, two types of catena-polyphosphate Ce(PO3)3 and Ce(PO3)4, and ultraphosphate CeP5O14). The formation of these products in the CeO2–H3PO4 system are notably different from these in other systems, showing that cerium(III) phosphates as well as cerium(IV) phosphates can exist stably. It can be seen from the X-ray diffraction patterns that each corresponding phosphate (ortho, catena-Qoly, and ultraphosphates) of lanthanum, cerium(III), praseodymium, neodymium, and samarium is isomorphous. This may be caused by the facts that the valencies of all these metals are +3 and that their ionic radii are almost equal to one another (La(III) 1.06 Å–Sm(III) 0.96 Å). The conditions of the formation of each phosphate were investigated, and the colors of the crystals, the densities, and the infrared absorption spectra of various rare earth phosphates were also examined.
Rate of Ligand Exchange of Tris(acetylacetonato)iron(III) with 2-Thenoyltrifluoroacetone in Organic Solvents
Authors: Sekine Tatsuya , Honda Hiroshi , Kokiso Masakazu , Tosaka Teruyuki 
Published: July 2006

Abstract
The rate of exchange of acetylacetonate ions (acac−) in tris(acetylacetonato)iron(III) with 2-thenoyltrifluoro-acetonate ions (tta−) has been measured in several organic solvents. The rate was independent of the concentration of Hacac and Htta and nearly the same in carbon tetrachloride, benzene, acetone, and 4-methyl-2-pentanone. However, the rate was much greater in ethanol. The rate of exchange in carbon tetrachloride, benzene, and acetone was found to be enhanced by water, ethanol, and several acids. The enhancement was smaller in acetone than in nonpolar solvents and the stronger the acid, the greater the catalytic effect. The rate controlling step of the exchange reaction was the rupture of an acetylacetonate ion from iron(III) in the complex. These observations have been discussed and possible mechanisms proposed.
Differential Pulse Polarographic Determination of Tellurium by Use of Maximum Wave
Authors: Hasebe Kiyoshi 
Published: July 2006

Abstract
A differential pulse polarographic method for the rapid and simple determination of tellurium by use of maximum wave has been studied. Differential pulse polarographic (DP) peak of tellurium(IV) in 1 mol dm−3 phosphoric acid is observed in the potential range −0.7–−1.0 V vs. SCE. The peak current is very large in comparison with that in d.c. mode, or in normal pulse mode, being proportional to the concentration of tellurium(IV) between 10−8 and 10−7 mol dm−3 contents. The relative standard deviation for 3.94×10−8 mol dm−3 tellurium(IV) under representative sets of good conditions was 0.0342. The method has been applied to the determination of tellurium in carbon steel.
Structure of 5-Hydroxy-2-hydroxymethyl-4-pyridones
Authors: Imafuku Kimiaki , Ishizaka Makoto , Matsumura Hisashi 
Published: July 2006

Abstract
5-Hydroxy-2-hydroxymethyl-4-pyridone and its N-methyl, N-ethyl, and N-phenyl derivatives were prepared from kojic acid. The UV spectra in neutral, acid, and alkaline solutions showed that the neutral species and the conjugate acids existed in the pyridone and the pyridine form, respectively. The conjugate bases may exist in both forms. The acid dissociation constants and the halochromism have been measured and discussed.
On the Behavior of Sulfonyl Imide as a Reactive Intermediate. The Reaction with Enamines
Authors: Nagai Toshikazu , Shingaki Tadao , Inagaki Masao , Ohshima Tetsuya 
Published: July 2006

Abstract
The reactions of N-alkylsulfamoyl chloride with enamines in the presence of triethylamine showed the presence of N-alkylsulfonyl imide (RN=SO2) as a reaction intermediate to give either acyclic (sulfonamides) or cyclic products (1,2-thiazetidine 1,1-dioxides), depending upon the enamines used. The enamines leading to the acyclic products possess either a methylene group on the α-carbon or a hydrogen on the β-carbon of the enamine; the enamine leading to the cyclic product has no such available hydrogen atom. It is thought that the products are formed via a zwitter ionic intermediate provided by the electrophilic attack of the sulfonyl imide sulfur atom on the β-carbon atom of the enamine.
The Beckmann Rearrangement in Concentrated Sulfuric Acid. Studies by Means of NMR and Kinetic Isotope Effect
Authors: Kim Seung-Geon , Kawakami Takeo , Ando Takashi , Yukawa Yasuhide 
Published: July 2006

Abstract
The mechanism of the Beckmann rearrangement of acetophenone (a) and 1-phenyl-2-propanone (b) oximes in concd sulfuric acid was elucidated by means of NMR spectroscopy and the carbon-14 kinetic isotope effect. For (a), the postulated reactive species acetophenone oxime hydrogensulfate was detected, the absence of hydrolysis of the oxime during the course of the reaction being verified. Positive carbon-14 kinetic isotope effect at the phenyl-1, k12/k14=1.026 at 40 °C and 1.019±0.005 at 60 °C, confirmed a definite change in bonding of the phenyl-1 carbon in the transition state of the reaction. Concertedness of the rearrangement was thus established. For (b), sulfonation of the benzene ring prior to the rearrangement was observed, kinetic isotope effect study being found to be useless.
An ESR Study of Polysubstituted N-Aryl-N-(arylthio)aminyls
Authors: Miura Yozo , Katsura Yosuke , Kinoshita Masayoshi 
Published: July 2006

Abstract
An ESR spectroscopic investigation of N-(2,4,6-trimethyl-, trimethoxy-, triisopropyl-, and tri-t-butylphenyl)N-(aiylthio)aminyls (2), Ar\dotNSAr′, is described. The aminyls are generated from the corresponding N-arylarenesulfenamides, ArNHSAr′, by hydrogen-abstraction, the aN values of which are 9.10–12.30 G and the g-values 2.0056–2.0067. On the basis of the ESR parameters the conformations for 2 have been discussed. Decay kinetic studies on 2 were conducted in benzene, and 2 were found to be persistent aminyls—particularly the t-butylsubstituted aminyl, N-(2,4,6-tri-t-butylphenyl)-N-(4-nitrophenylthio)aminyl.
Reactions of 2-Chlorothiophene with Cation Exchange Resin and 100% Orthophosphoric Acid. Formation of the Dimer Type Products Containing a Tetrahydro-2-thiophenone Moiety
Authors: Sone Tyo , Shiromaru Osamu , Igarashi Shin-ichi , Kato Eiichi , Sawara Mutsuo 
Published: July 2006

Abstract
It has been found that 2-chlorothiophene is converted into the dimer type products by Amberlyst 15 or 100% orthophosphoric acid, the reaction yielding 4- and 5-(5-chloro-2-thienyl)tetrahydro-2-thiophenones and 4-(2-thienyl)-2(5H)-thiophenone together with 5-chloro-2,2′-bithienyl. The distribution of the products is considerably affected by the acid used and in the presence of phenol or anisole the reaction affords additionally 4-[5-(p-hydroxyphenyl)-2-thienyl] tetrahydro-2-thiophenone or 4-[5-(p-methoxyphenyl)-2-thienyl] tetrahydro-2-thiophenone, respectively.
An Improved Synthesis of 3′,4′-Dideoxykanamycin B
Authors: Yoneta Toshio , Shibahara Seiji , Matsuno Tomio , Tohma Susumu , Fukatsu Shuzo , Seki Shigeo , Umezawa Hamao 
Published: July 2006

Abstract
A new synthetic route has been exploited for the large scale production of 3′,4′-dideoxykanamycin B starting with kanamycin B. The key stage in the synthesis involves the formation in excellent yield of the 3′,4′-anhydro-4′-epi derivative (5) followed by convertion to the 3′-ene derivative through the iodohydrin. Compound 5 was prepared by the treatment of 3′,2″-di-O-benzoyl-4″,6″-O-cyclohexylidene-4′-O-methylsulfonyl-penta-N-t-butoxycarbonyl-kanamycin B with sodium methoxide.
Odor and Volatile Compounds in Liquid Swine Manure. III. Volatile and Odorous Components in Anaerobically or Aerobically Digested Liquid Swine Manure
Authors: Yasuhara Akio , Fuwa Keiichiro 
Published: July 2006

Abstract
Volatile and odorous components were isolated from anaerobically or aerobically digested liquid swine manure by direct solvent-extraction and flash-distillation under reduced pressure. The concentrations of indole, oxindole, dimethylsulfoxide, phenol, and a few carboxylic acids increased, and o-aminoacetophenone decreased during digestion. Alkaline components were not so important for the odor. Offensive odor was formed by mixing phenols and carboxylic acids. Complete aeration resulted in a remarkable decrease of lower carboxylic acids.
New C31 Secodammarane-type Triterpenoids, Alnuseric Acid and Alniselide, in the Male Flowers of Alnus serrulatoides
Authors: Suga Takayuki , Hirata Toshifumi 
Published: July 2006

Abstract
Two novel C31 3,4-secodammarane-type triterpenoids, alnuseric acid and alnuselide, were isolated from the male flowers of Alnus serrulatoides Call. (Betulaceae); their structures were elucidated to be (20S,24R)-20,24-epoxy-24-methyl-3,4-secodammar-4(28)-en-3-oic acid and (11R,2OS,24R)-20,24-epoxy-24-methyl-3,4-secodammar-4(28)-en-3,11α-olactone, respectively, by a combination of chemical and spectroscopic methods.
Pseudo-sugars. 3. Alternative Synthesis of Penta-N,O-acetyl-Dl-validamine and Its Analogs
Authors: Ogawa Seiichiro , Kasahara Isamu , Suami Tetsuo 
Published: July 2006

Abstract
Dl-Validamine and its amino deoxy and deoxy analogs were synthesized as the acetyl derivatives from endo-7-oxabicyclo[2.2.1]hept-5-ene-2-carboxylic acid, the Diels-Alder adduct of acrylic acid and furan.
14N Nuclear Quadrupole Relaxation Near the Plastic Transition Point in the Low-temperature Phase of 1,4-Diazabicyclo[2.2.2]octane
Authors: Negita Hisao , Maekawa Michio , Kubo Tsuneo , Okuda Tsutomu 
Published: July 2006

Abstract
The relaxation mechanism near the plastic transition in the low-temperature phase of 1,4-diazabicyclo[2.2.2]octane is attributed to the overall molecular tumbling. The activation energy is 23.0 kJ mol−1, which is nearly equal to the value of 22.2 kJ mol−1 in the proton NMR in the plastic phase.
The Dimorphism and Spectral Properties of 4-Anilino-1,2-naphthoquinones
Authors: Matsunaga Yoshio , Miyajima Nobuhiko 
Published: July 2006

Abstract
On the basis of vibrational spectra, especially in the region from 3050 to 3350 cm−1, solid 4-anilino-1,2-naphthoquinones carrying substituents on the phenyl ring are classified into two groups. The p-methyl and p-ethyl derivatives are dimorphic and can be members of both the groups.
Formation of Vaterite by the Reaction of Calcium Methoxide with Aqueous Sodium Carbonate Solution
Authors: Yamaguchi Osamu , Takashita Noriyuki , Shimizu Kiyoshi 
Published: July 2006

Abstract
A mixture of vaterite and calcite was formed by the reaction of calcium methoxide with aqueous sodium carbonate solutions. The reaction temperature was found to be a dominant factor for the formation of vaterite. The kinetics of the transformation of vaterite into calcite was studied.
Studies on 1,2,4-Thiadiazolidine Derivatives. IV. The Isomers of 2,4-Disubstituted 3,5-(Disubstituted imino)1,2,4-thiadiazolidines
Authors: Kinoshita Takeshi , Sato Sadao , Tamura Chihiro 
Published: July 2006

Abstract
Several 2-alkyl-5-alkylimino-4-aryl-3-arylimino-1,2,4-thiadiazolidines and 4-alkyl-5-alkylimino-2-aryl-3-arylimino-1,2,4-thiadiazolidines were synthesized by the oxidation of 1-alkyl-3-arylthioureas with benzoyl peroxide along with 2,4-dialkyl-3,5-bis(arylimino)-1,2,4-thiadiazolidines.
Liquid Phase Peptide Synthesis by the Fragment Condensation on Soluble Polymer Support. II. The Azide Method
Authors: Narita Mitsuaki 
Published: July 2006

Abstract
Fragment condensation on a soluble polymer support by the azide method gave rise to the efficient coupling (94–99% yield) of an N-protected tetrapeptide azide with the amino acid anchored to the soluble polymer support. Bulkiness of amino acid residues on the polymer support did not affect the reactivity toward the peptide azide.
ESR Spectrum of Bis(dibenzoylmethanato)oxovanadium(IV) Dissolved in Molten and Crystalline Charge Transfer Complexes
Authors: Araya Kotaro , Matsunaga Yoshio , Ochi Eiji 
Published: July 2006

Abstract
The ESR spectrum of bis(dibenzoylmethanato)oxovanadium(IV) dissolved in a number of pyrene and fluoranthene complexes with aromatic polynitro compounds just above their melting points indicates that the motion of the spin probe is more or less restricted. In some favorable cases, the high effective viscosity of the melts can be partially attributed to the association of the electron donor and acceptor molecules. No abrupt change in the ESR spectral pattern is noted upon solidification and the motion of the probe gradually ceases upon lowering the temperature. Therefore, the lattice appears to be not rigid in these crystalline complexes. On the other hand, the ESR spectrum observed in the molten naphthalene-dinitrophenol complex is not far from isotropic at the melting point. Because of the segregation of the probe upon solidification, the measurements on this solid complex could not be made.
Nuclear Magnetic Resonance Studies of the Cu-chlorophyllin Complex with Flavine Mononucleotide
Authors: Enmanji Koe 
Published: July 2006

Abstract
The NMR relaxation time of the Cu-chlorophyllin (Cu-chln)–flavine mononucleotide (FMN) complex was measured, and its geometrical structure was proposed. The complex has an absorption band at 700 nm which is attributed to complex formation by analogy with the chlorophyll a–FMN complex. Its binding constant is 330 l/mol at 25 °C; this value is larger than those of other Cu-chln complexes. From the analysis of its ESR data, it is clear that the greater part of the electron spin in Cu-chln is distributed on the Gu2+ ion. The distance between the nuclear and electron spins was calculated by measuring the spin-lattice relaxation times. From these results, the distance between the porphyrin ring and the isoalloxazine ring in the Cu-chln-FMN complex molecule is found to be 4.2 Å if the two rings are parallel to each other. The chlorophyll a-FMN complex is assumed to have a similar geometrical structure.
Disintegration of Sulfonated Poly(1,4-piperazinediylterephthaloyl)Microcapsules by Poly(diallyldimethylammonium chloride)
Authors: Suzuki Shiro , Kondo Tamotsu 
Published: July 2006

Abstract
Partially sulfonated poly(1,4-piperazinediylterephthaloyl) microcapsules were found to undergo disintegration by the action of poly(diallyldimethylammonium) ions if the polycation concentration exceeded a certain value. The polycation concentration at which disintegration started was dependent on the degree of sulfonation of the microcapsules and pH of the medium. Exact electrical equivalence of the polyions involved was shown to be a necessary condition for disintegration of the microcapsules to take place. Disintegration of the microcapsules resulted in a formation of coacervate-like liquid drops. This formation of coacervate-like liquid was accelerated by mechanical and thermal agitation. Crosslinking among the polymers constituting the microcapsules prevented disintegration from occurring.