bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of the Organic Reactions of Metal Carbonyls. XIV. The Reaction of Potassium Iron Carbonylates with Isoprene
Authors: Takegami Yoshinobu , Watanabe Yoshihisa , Kanaya Isao , Mitsudo Takeaki , Okajima Toshiharu , Morishita Yoshihiko , Masada Hiromitsu 
Published: July 2006

Abstract
The reaction between potassium iron carbonylates (KHFe(CO)4, K2Fe(CO)4 and K2Fe2(CO)8) and isoprene has been studied. Isoprene is reduced at room temperature to give three olefins (3-methyl-1-butene (I), 2-methyl-1-butene (II), and 2-methyl-2-butene (III)). The reaction conditions (solvents, atmospheres, additives such as water) have a great effect on the yield and distribution of the olefins. Under carbon monoxide in the presence of water, the reduction is highly promoted, giving 2 mol/mol-Fe(CO)42− of the olefins. The percentage of II is almost constant (about 15%) in any case, but the percentages of I and III, very dependent on the conditions, change in the 3–40 and 50–80% ranges respectively. The reaction is suggested to proceed via some kinds of σ- and π-allyl iron carbonyl complexes. Under carbon monoxide the carbonylation of isoprene also occurs.
Copolymerization of Vinyl Chloride with Ethylene by the VO(OEt)3-Alkylaluminum Catalyst Systems
Authors: Misono Akira , Uchida Yasuzo , Yamada Kunikazu , Saeki Tadashi 
Published: July 2006

Abstract
The copolymerization of vinyl chloride with ethylene was carried out in n-heptane by using the catalyst systems consisting of VO(OEt)3 and AlEt3, AlEt2Cl, or AlEtCl2 at 50°C. It was found that each of the above catalyst systems produces a random copolymer at Al/V molar ratios below 1.5; however, polyethylene is mainly obtained above the ratio of 1.5. With the VO(OEt)3/AlEt3 catalyst system, its good catalyst activity being in contrast with the inactivity of the Ti(O-n-Bu)4/AlEt3 catalyst system, the maximum catalyst activity was observed at the Al/V molar ratio of 0.5. The copolymerization rate decreased with an increase in the ethylene fraction in the monomer mixture, reaching a minimum value at a 80 mol% ethylene feed; however, the rate increased above this feed ratio with a further increase in the ethylene feed. The contamination of a copolymer with polyethylene which has been observed in the copolymerization by the Ti(O-n-Bu)4/AlEt2Cl or AlEtCl2 catalyst system was not observed in the present case. The monomer reactivity ratios for the copolymerization by the VO(OEt)3/AlEt3 catalyst system were found to be r1(vinyl chloride)=2.48 and r2(ethylene)=0.02. The reaction between VO(OEt)3 and AlEt3 was investigated by means of infrared spectroscopy and gasometry, and it was found that the average valency states of the V of the catalyst system is higher than four at the Al/V molar ratio range where a random copolymer is exclusively obtained.
The Reductive Coupling Reactions of Benzyl Chloride by Copper(I) Complexes
Authors: Wada Keisuke , Hashimoto Harukichi 
Published: July 2006

Abstract
The reactions between benzyl chloride and cuprous chloride were studied. It was found that good yields of bibenzyl were obtained by the addition of ethylenediamine, diethylenetriamine, triethylenetetramine, acetylacetone and EDTA. Nothing of bibenzyl was observed in the cases of ethanolamine, pyridine, dipyridyl, phenanthroline and triphenylphosphine. These facts, together with the spectral studies of copper complexes can reasonably be explained by the formation of reactive species of the type CuI(en)nCl. The course of the reaction was discussed on the basis of the substituent and medium effects. Radical but not free type mechanisms which include the transient organocopper species were considered. Some additional comments were also made.
Sterically Controlled Syntheses of Optically Active Organic Compounds. XIX. Asymmetric Syntheses of Amino Acids by the Strecker Reaction
Authors: Harada Kaoru , Okawara Tadashi , Matsumoto Kazuo 
Published: July 2006

Abstract
The Strecker type syntheses of optically active alanine, butyrine, valine, and leucine by the use of the corresponding aldehydes, hydrogen cyanide, and optically active α-alkylbenzylamines and α-(1-naphthyl)ethylamine were carried out (reaction A). The optical purities were in the range 22–51%. The modified Strecker type syntheses of alanine from acetaldehyde cyanohydrine and optically active amines were also carried out (reaction B). The optical purities of alanine were in the range 44–48%. In reaction B, optically active phenylglycine was also used as an amino source. The optical purities of the synthesized alanine were in the range 12–17%.
Ionic Photodissociation of Electron Donor-Acceptor Complexes
Authors: Shimada Motoo , Masuhara Hiroshi , Mataga Noboru 
Published: July 2006

Abstract
Ionic photodissociation of electron donor-acceptor (EDA) complexes of s-tetracyanobenzene (TCNB) and pyromellitic dianhydride (PMDA) with 2-methyltetrahydrofuran (MTHF) has been investigated by means of nsec flash photolysis and transient photocurrent measurements. The solvent-shared ion-pair of TCNB anion and MTHF cation is formed from the excited charge-transfer (CT) singlet state of a TCNB–MTHF complex, dissociating into solvated ions. TCNB complexes with aromatic hydrocarbons dissociate directly into ions from the lowest excited CT singlet state. Dissociation of PMDA complexes occurs in the CT triplet state in nonpolar solvents and mainly in the excited CT singlet state in polar solvents. The relative rate constant of radiationless process, which competes with ionic dissociation in the excited singlet state, can be deduced from the effect of solvent on ionic photodissociation. It has been confirmed for the first time that the ionic dissociation of a TCNB–benzene–1,2-dichloroethane (DCE) system occurs in the excited Franck-Condon (FC) state. It is pointed out that the latter dissociation mechanism is not inconsistent with all the results obtained for TCNB and PMDA complexes under various conditions.
Dipole Correlation Functions of Non-interacting Symmetric Vib-rotors
Authors: Yamashita Teruyo , Shimizu Hiroshi 
Published: July 2006

Abstract
Dipolar correlation functions of non-interacting symmetric top molecules were obtained by quantum mechanical calculation. The effect of the rotation-vibration interaction on the correlation function is discussed, taking the constant ζ of the Coriolis coupling and the asymmetry Ix/Iz as parameters. It is shown that the decay of the correlation function for perpendicular vibrations very much depends on the sign and the magnitude of ζ. Some relationships between the shape of the correlation function and the value of the parameters are given.
The Photoconductivity of Poly(N-vinylcarbazole). II. Dark Conductivity in a Sandwich-type Cell
Authors: Okamoto Kenichi , Kusabayashi Shigekazu , Mikawa Hiroshi 
Published: July 2006

Abstract
The dark conductivity in a sandwich-type cell of PVCz films was investigated in a high vacuum, taking the temperature, the applied voltage, and the film thickness as parameters. In low fields, the conductivity was proportional to the applied voltage. In high fields, however, it was proportional to the fourth power of the applied voltage. This nonohmic dark conductivity in high fields may be attributed to the Pool-Frenkel effect. A model of the energy-level diagram is presented which can explain the dark conductivity in both low and high fields.
Neutral Salt Effect on the Interaction of Poly-α, l-glutamic Acid with Acridine Orange
Authors: Sato Yukio , Hatano Masahiro , Yoneyama Michio 
Published: July 2006

Abstract
The effect of potassium chloride on the absorption and optical rotatory properties of the poly-α,l-glutamic acid-acridine orange system in an aqueous solution was studied under various conditions. The stability of the helical conformation of poly-α,l-glutamic acid in this system was examined at different potassium chloride concentrations by estimating the helix fraction of the polymer. At pH 4.5, where poly-α,l-glutamic acid exists in the helix, it was found that the added potassium chloride raised the stability of the helical conformation of the polymer in this system. In this case, it was assumed that the added potassium chloride lowers the disturbance of helix formation by the bound acridine orange cation. However, when the solution’s pH was raised, the added potassium chloride lowered the extent of the helix fraction in this system. These phenomena were discussed on the basis of several experimental findings on the circular dichroism of the systems. Furthermore, from the change in the intensities of the circular dichroism with the variation in the potassium chloride concentration, it was presumed that the positive circular dichroism band at about 520 nm was due to the binding of dimeric acridine orange molecules to the polymer.
ESR Studies of Stable Free Radical Pairs in the Diamagnetic Matrix Crystal
Authors: Takizawa Osamu , Yamauchi Jun , Ohya-Nishiguchi Hiroaki , Deguchi Yasuo 
Published: July 2006

Abstract
The radical pair system of a stable free radical, di-p-anisyl-nitric-oxide (DANO), has been observed in the magnetically-diluted crystal of 4,4-dimethoxy-benzophenone. The existence of the radical pair has been ascertained by the characteristic ESR absorptions, which give rise to the zero-field splitting and half-field resonance, of the powdered sample as well as by a comparison of the magnitude of the hyperfine coupling constant of the isolated radical with that of the pair system. The precise ESR measurements were performed using a single crystal containing 7.5% DANO radicals oriented well in the diamagnetic matrix. The fine structure parameters, |D| and |E|, have been determined to be 186 Gauss and 2 Gauss respectively, from which the distance between the two radical molecules in the pair system is estimated to be 5.4 Å. In order to deduce the structures of the radical pair, the g-value and the hyperfine coupling constant of the isolated radical have also been determined.
The Triplet Excitons in the Anion Radical Salts of [(C6H5)3PCH3]1−x+[(C6H5)3AsCH3]x+ (TCNQ)2÷, (0≤x≤1)
Authors: Suzuki Yukio , Iida Yôichi 
Published: July 2006

Abstract
The electron spin resonance (ESR) absorption and its variation with the temperature were measured with single crystals of the anion radical salts containing the mixed cations, [(C6H5)3PCH3]1−x+ [(C6H5)3AsCH3]x+(TCNQ)2\ewdot, (0≤x≤1). The paramagnetic excited state of these salts is triplet in character, as was shown from the anisotropic zero-field splitting at low temperatures. The triplet state is not localized, but, rather, corresponds to the triplet exciton state. The exciton exchange frequency and its temperature dependence were determined by analyzing the line shapes of the ESR spectra. The exciton motion in the mixed crystal system was investigated in order to establish the character of the triplet excitons in ion radical salts.
The G-values of Nitrogen Obtained from the Gas-phase γ-Radiolysis of Nitrous Oxide–Hydrocarbon Systems
Authors: Okazaki Kiyoshi , Yugeta Rei , Sato Shin 
Published: July 2006

Abstract
The gas-phase γ-radiolysis of a N2O-1-butene system has been reinvestigated. The other hydrocarbons used for the substrate are ethylene, propylene, 1,3-butadiene, cyclopropane, propane, and n-butane. The G-value of nitrogen from any system increased with an increase in the pressure of N2O and was saturated at about 4 mol% of N2O. The saturated value, G(N2)max, was much larger than the G-value of electrons estimated from the W-value of the hydrocarbon used and was rather strongly dependent upon the irradiation temperature, the dose rate, and the total dose. Some of the results were not consistent with those reported by the previous investigators. The reason for this discrepancy, and also the possible reaction mechanism to explain the large G(N2)max, have been discussed.
Crystal Structure of μ-Peroxo-bis[nitrobis(ethylenediamine)cobalt(III)] Dinitrate Tetrahydrate
Authors: Shibahara Takashi , Koda Shigetaka , Mori Masayasu 
Published: July 2006

Abstract
The crystal and molecular structure of μ-peroxo-bis[nitrobis(ethylenediamine)cobalt(III)] dinitrate tetrahydrate, [NO2(en)2CoO2Co(en)2NO2](NO3)2·4H2O has been determined using visual intensity data of three dimensional Weissenberg photographs taken with Ni-Kα radiation. The brown-black salt is monoclinic with space group P21/n and cell dimensions a=10.755±0.011, b=12.941±0.008, c=9.709±0.006 Å, and β=100.4±0.1°. The least-squares refinement with anisotropic temperature factors gave an R index of 0.106. The coordinating ligands form nearly regular octahedra about the cobalt atoms, with Co–N(en), Co-N(NO2), and Co–O distances of about 1.95, 1.94, and 1.89 Å, respectively. Both NO2−,s are trans to the O–O bridge, and the geometry of Co-O-O-Co is trans planar with O–O distance of 1.53 Å and Co–O–O angle of 110°. The two Co–(en)2 moieties have δδ and λλ conformations.
The Vibrational Assignments of Propyl Bromide and Its Two Asymmetrically-Deuterated Species
Authors: Hayashi Michiro , Ohno Keiichi , Murata Hiromu 
Published: July 2006

Abstract
The vibrational assignments of the observed spectra of propyl bromide and its two asymmetrically-deuterated species have been worked out. Since the two gauche isomers come not to be equivalent for the asymmetrically-deuterated species, the infrared bands of the gauche isomer can be expected to be split into doublets, while the bands of the trans isomer remain singlets. The observed infrared bands for the gauche isomer were actually the doublets for the C–Br stretching and two CH2 rocking modes. The C–D stretching and deformation modes of the β-deuterated species were also in the expected spectral patterns. In order to confirm the vibrational assignments, the normal vibration calculation was carried out using a modified Urey-Bradley force field for the parent and two asymmetrically-deuterated species.
Racemization and Isotopic Exchange of Tris(acetylacetonato)silicon(IV) Perchlorate in Organic Solvents
Authors: Inoue Tomoaki , Saito Kazuo 
Published: July 2006

Abstract
Racemization of trisacetylacetonatosilicon(IV) ions and their isotopic exchange reaction with acetylacetone-14C (Hacac) have been studied in tetrachloroethane (TCE) and acetonitrile (AN). No solvolysis takes place at least below 60°C, and the racemization rate R is expressed as follows: R=[complex] (k1+k2[acid]) (in TCE) and R=[complex] (k3+k4[base]) (in AN). The rate constants and activation parameters at 50°C are as follows: rate constants, 4.79×106 s−1, 1.35×10−4 M−1 s−1, 3.87×10−5 s−1 and 1.19×10−1 M−1 s−1, activation enthalpy (ΔH\eweq/kcal mol−1) 31.6±0.1, 29.3±1.9, 25.7±0.2 and ca. 18, and activation entropy (ΔS\eweq/cal mol−1K−1) 14.6, 14.2, 0.53, −5.75, respectively, for k1, k2 (for trichloroacetic acid), k3 and k4 (for 2,6-lutidine). No isotopic exchange is observed within 6 hr at 60°C in the solvents. The racemization should proceed intra-molecularly and presumably via an intermediate of coordination 5 with one of the ligands as unidentate.
Studies of the Ruthenium(III) Complex. V. Aquation and Anation Reactions of Halogenoacetatopentaammineruthenium(III) Complexes in Aqueous Solutions
Authors: Ohyoshi Akira , Shida Satoshi , Izuchi Shuichi , Kitagawa Futoshi , Ohkubo Katsutoshi 
Published: July 2006

Abstract
The kinetics of aquation and anation reaction have been studied with pentaamineruthenium(III) complexes containing halogenoacetates (fiuoro-, monochloro-, dichloro-, trichloro-, bromo-, and iodoacetates). It has been found that the aquation reaction proceeds through two kinds of paths, i.e. the acid-catalysed path and the aciduncatalysed path, except the cases of dichloro- and trichloroacetate complexes. The aquations of dichloro- and trichloroacetate complexes are not catalysed by a proton because these ligand acids are strong acids. The equilibrium constants between [RuH2O(NH3)5]3+ and [RuO2CRX(NH3)5]2+ (O2CRX=halogenoacetate), Keq, were calculated from the anation and aquation rate constants. The kaq and Keq values for the fiuoro-, chloro-, dichloro-, trichloro-, bromo-, and iodoacetatocomplexes are, respectively: kaq, 10×10−5, 7.5×10−5, 19.1×10−5, 49.0×10−5, 6.8×10−5 and 6.7×10−5 sec−1; Keq, 5.2×10−3, 3.6×10−3, 9.0×10−3, 23×10−3, 3.5×10−3, and 3.3×10−3 M, at 60°C. The free energy plot, logkaq vs. logKeq, gave a straight line with a gradient of 1.0. It has been concluded that the acid-uncatalysed reaction proceeds via a SN1 mechanism, while the acid-catalysed reaction seems to take place with a SN2 mechanism. Some remarks have been made on the molecular interaction between the complex and the acid catalyst.
Photochemical Reduction of p-Quinones with Hydrogen Donors Studied by CIDNP Technique
Authors: Maruyama Kazuhiro , Otsuki Tetsuo , Takuwa Akio , Arakawa Seiichi 
Published: July 2006

Abstract
Photo-reduction of p-benzoquinone, 1,4-naphthoquinone, and their methyl- or chloro-derivatives has been investigated by means of CIDNP technique. Strongly polarized PMR signals due to unstable reaction intermediates, p-quinones, and hydroquinones were observed during the course of reaction. Structures of the unstable reaction intermediates, none of which accumulated as reaction products, were determined, their polarized PMR signals being compared with those of the unstable reaction intermediates resulting from the deuterated substrates. From these results, a reaction scheme for these photo-reduction was proposed.
The Photoconductivity of Poly(N-vinylcarbazole). V. The Doping Effects of Various Materials on the Photoconductivity
Authors: Okamoto Kenichi , Kusabayashi Shigekazu , Mikawa Hiroshi 
Published: July 2006

Abstract
The photoconductivity and fluorescence spectra of poly(N-vinylcarbazole) (PVCz) films doped with various materials were investigated. The photoconductive properties of doped films may be grouped into three classes according to the kind of dopant. The doping of an electron donor, such as tetramethyl-p-phenylenediamine and 1,5-diaminonaphthalene, reduced the photocurrent in all the wavelength regions by a factor of 102 to 104 because of the hole-trapping effect of the dopant molecule. The exciplex formed between the donor and PVCz does not seem to contribute to the photocurrent. The doping of an acceptor, such as TCNE and dimethyl terephthalate, on the other hand, enhanced the photocurrent. The field-assisted thermal dissociation of an excited CT complex formed between PVCz and an acceptor seems to be a carrier generation process. The doping of anthracene or perylene quenched the fluorescence of PVCz by a factor of 10 to 30 and reduced the photocurrent in the UV region by a factor of 2 to 7, while it enhanced the photocurrent in the absorption region of the dopant.
Emission Spectra of Benzene, Toluene, and Xylenes by Controlled Electron Impact
Authors: Ogawa Teiichiro , Tsuji Masaharu , Toyoda Minoru , Ishibashi Nobuhiko 
Published: July 2006

Abstract
The emission spectra of gaseous aromatic hydrocarbons under electron impact excitation (60–300 eV) were measured in the 220–450 nm region at very low pressures. A characteristic band was observed in all cases in the 240–340 nm region; this band was assigned to the transition from the lowest excited singlet state to the electronic ground state. Photoemissions from the fragment species, such as H (Balmer series) and CH (A→X, B→X), were also observed. The excited species were concluded, from the relations of the emission intensities to the electron-beam current and to the gas pressure, to be produced by one-electron processes. The relative intensity and the vibrational structure of the observed spectra were examined and compared with those of the fluorescence spectra produced by photo-excitation.
The Crystal Structure of Cinchomeronic Acid
Authors: Takusagawa Fusao , Hirotsu Ken , Shimada Akira 
Published: July 2006

Abstract
The crystal structure of cinchomeronic acid (3,4-pyridinedicarboxylic acid) has been determined by the method of X-ray diffraction. The crystals are orthorhombic, with a space group of P212121, and with cell dimensions of a=11.211, b=11.206, and c=5.285 Å. The structure was determined by the method of symbolic addition. The final R value was 5.90% for 828 observed reflections. The molecule takes the form of a zwitter ion in the crystal. The pyridine ring has, approximately, the C2v symmetry. One carboxyl group consists of C=O and C–O (H) groups, while the other consists of two O(Remark: Graphics omitted.)O groups. These carboxyl groups twist out of the plane of a pyridine ring by 39.6° and 73.0° respectively. The hydrogen bonds are in the forms of two spirals around the two-fold screw axes parallel to the c axis, thus linking the molecules three-dimensionally. There are four molecules per turn of the spiral along the c axis. The carbonyl oxygen atom O(2) is free from the hydrogen bond, while the nitrogen atom N(l) in the pyridine ring participates in it. The relations between the C–N–C bond angle of the pyridine ring and the N···H distance, and also between the net charge on the nitrogen atom calculated by the “complete neglect of differential overlap” (GNDO) method and the O···N distance for a hydrogen bond are discussed in connection with five pyridine-carboxylic acids.
Catalysis of Manganese Salts in the Autoxidation of Cyclohexanone
Authors: Kamiya Yoshio , Kotake Masayoshi 
Published: July 2006

Abstract
The rate of oxidation of cyclohexanone catalyzed by manganese salt increases remarkably in the presence of acetic acid, and is about one hundred times as high as the limiting rate of oxidation kp2(RH)2/2kt. However, manganese concentration does not affect the rate of oxidation much in a wide range. The oxidation of cyclohexanone by manganic ion should be the rate determining step, since the rate of oxidation, which is of first order in cyclohexanone but independent of manganous ion, corresponds to the rate of oxygen absorption of cyclohexanone with the same manganese concentration. The oxidation of cyclohexanone by manganic ion seems to proceed through enol intermediates, since the rate of oxidation increases in the presence of alkali acetates. The rate equation including enolization step and the subsequent oxidation of enol intermediate with manganic ion agrees with the experimental results. A remarkable synergistic effect of metal salts was observed in a mixture of manganese and cobalt. The oxidation products were also analyzed and discussed.
Synthesis and Substitution of 1,3,4,6-Tetra-substituted-3,6-dihalogeno-2,5-piperazinediones
Authors: Yoshimura Juji , Sugiyama Yuichi , Nakamura Hiroshi 
Published: July 2006

Abstract
Addition of chlorine to 3,6-dimethylene- (3) and 3,6-dibenzylidene-1,4-dimethyl-2,5-piperazinediones gave isomers of the corresponding tetrachloride, and substitution of 1,3,4,6-tetramethyl-2,5-piperazinedione with bromine also gave tetrabromide (2) of the same type via successive elimination and addition reactions. Treatment of 2 with water and with methanolic sodium acetate gave the corresponding 3,6-dihydroxy and dimethoxy derivatives, respectively, while treatment with sodium iodide, sodium sulfide, sodium thiocyanate, or sodium thioacetate gave only 3 and sulfur in a good yield. Similar results were obtained in the case of octahydro-5H,10H-dipyrrolo[1,2-a: 1′,2′-d]pyrazine-5,10-dione. However, bromination of 6,13-dioxo-6a,7,13a,14-tetrahydro-6H,13H-pyrazino[1,2-a: 4,5-a′]diindole gave rise only to aromatization. Configurations of the isomers obtained and the reaction processes were discussed.