bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermodynamics of the Redox Equilibria and the Site Preference in(Fe1−yAly)3−δO4
Authors: Nakamura Akio , Yamauchi Shigeru , Fueki Kazuo , Mukaibo Takashi
Published: July 2006

In order to elucidate the defect model in the spinel ferrites, the nonstoichiometry in magnetite and its solid solutions, (Fe1−yAly)3−δO4, (y=0.0, 0.25, 0.33), was determined at temperatures between 1300 and 1550 °C. The redox equilibria between Fe2+ and Fe3+ and the site preference of Fe2+, Fe3+, and Al3+ ions and cation vacancies were investigated and sixteen kinds of models were examined. The “best” model was chosen using the criteria that the dependence of the equilibrium constant on δ and y should be as small as possible. In the selected model, Fe2+ ions on B-sites are regarded as electron donors in a narrow 3-d band formed by Fe ions in B-sites. The following expression for the defect equilibrium was found:

\frac23(1−y)FeA2++\frac2(2−3y)3(1−y)eB−+\frac12O2(g)\ightleftarrows\frac23(1−y)FeA3++\frac14VA+\frac12VB+OL2−.
The Chemistry of Americium. IV. The Stability of Am(V) and Am(VI) in Nitric Acid Solutions and in the Solutions Containing Ozone Gas Fluoride, or Phosphate Ions
Authors: Hara Mitsuo , Suzuki Shin
Published: July 2006

The coprecipitation technique with BiPO4 and ThF4 was applied to studying the stability of Am(V) and Am(VI) at concentrations lower than 10−6 M. It was found that 241Am(V) and 241Am(VI) were rapidly reduced to 241Am(III) in nitric acid solutions at low acidities and at high temperatures, but the reduction was effectively inhibited by the presence of ozone gas or fluoride ions. On the other hand, 243Am(V) and 243Am(VI) were found to be rather stable in nitric acid solutions, while they were readily reduced to 243Am(III) in phosphate solutions in the same manner as 241Am(V) and 241Am(VI).
Color Reactions of Aqua(ethylenediaminetetraacetato)ruthenate(III) with Sulfur Compounds. Kinetic Study of Thiosulfate Anation
Authors: Yoshino Yukichi , Uehiro Takashi , Saito Masami
Published: July 2006

New color reactions of aqua(ethylenediaminetetraacetato)ruthenate(III) with sulfur compounds such as thiols, thiourea and thiosulfate have been found and investigated. It has been established that the coloration is due to the anation of the complex with sulfur compounds. In the case of thiosulfate, the reaction is first order in either reactant and independent of [H+] in the pH range 4 to 6. The rate constant (kAN) was found to be 2.94±0.11 M−1 s−1 at 30 °C and I=0.1. For a pH>6, the rate decreases with increase in pH due to the formation of a hydroxo complex. In the higher pH region, the reverse reaction, [Ru(edta) (S2O3)]3−+OH−\ightleftarrows[Ru(edta) (OH)]2−+S2O32− takes place. From the value of the equilibrium constant (Keq) for this reaction, the equilibrium constant (KAN) for thiosulfate anation has been estimated as, logKAN=5.02 at 30 °C and I=0.1.
Synthesis of Methyl Substituted Chromanol. An Analogue of Vitamin K
Authors: Maruyama Kazuhiro , Tobimatsu Takamasa , Naruta Yoshinori
Published: July 2006

Methylation of 2,2-dimethyl-3,4-dihydro-2H-benzo[h]chromen-6-ol (1) is examined to yield 2,2,3-trimethyl-3,4-dihidro-2H-benzo[h]chromen-6-ol (2). The compound 2 is prepared by Mannich reaction followed by hydrogenative cleavage of the Mannich bases, which are obtained in the reaction with three kinds of amine. Chloromethylation of 1 quantitatively gave a dimer of naphthoquinone methide.
Studies of Polymeric Flocculants. IX. The Formation of Poly(methacrylohydrazide)–Copper(II) Complexes
Authors: Nonaka Takamasa , Momono Eiji , Egawa Hiroaki
Published: July 2006

Formation constants for the complexes of poly(methacrylohydrazide) (PMH) with the copper(II) ion were measured by using a modification of Bjerrum’s method proposed by Gregor and his coworkers. The pKa1 and pKa2 values of PMH determined in an aqueous solution with an ionic strength of 0.1 (KNO3) at 25 °C were 3.20 and 10.61 respectively. Therefore, when the PMH-copper(II) complexes were formed above pH 7, the average number of ligands combined with one metal ion could be calculated approximately without using the first acid dissociation constant. The pKa2 value decreased with an increase in the ionic strength and temperature. The formation curves of the complexes showed that one copper(II) ion formed a coordination compound with six hydrazide groups in a high pH region (about pH 9). The formation constants increased with an increase in TCu/THL (the ratio of the total concentration of the copper(II) ion to the total concentration of the ligand) in the range higher than 0.1. The formation constants were unaffected by the degree of polymerization of PMH in the range from 64.1 to 5470, but the formation constants were affected by the kind of anion in copper(II) salts and neutral salts added and they increased in the order of NO3−<SO42−<Cl−. The thermodynamic parameters for the above reaction were determined by Ringbom’s method.
The Conformation and the Ring Inversion of 8,9,10,11-Tetrahydro-7H-cycloocta[de]naphthalene
Authors: Kamada Toshihiro , Yamamoto Osamu
Published: July 2006

The 1H-NMR spectra of 8,9,10,11-tetrahydro-7H-cycloocta[de]naphthalene (1) and its 8,8,10,10-tetradeuterio derivative have been studied at various temperatures. The NMR parameters of compound 1 were determined accurately by means of computer analysis of the low-temperature spectrum. It was found that the ground-state conformation of 1 is a boat, which is somewhat in a distorted form (puckering) as a result of the steric repulsion between the interior benzyl protons. Activation parameters ΔG\eweq, ΔH\eweq, and ΔS\eweq for the boat inversion process in the molecule were obtained by the line-shape analysis method as 14.5, 16.1 kcal/mol and 5.4 e.u., respectively. These results are best explained in terms of a conformational interconversion process in which the pseudorotations of the peri bonds are involved. Some discussion is also made on the conformational properties of compound 1 in comparison with those of the structurally analogous benzocyclic compound 6,7,8,9-tetrahydro-5H-benzocycloheptene.
The Acid-catalyzed Reactions of 4-Chromanones with Formaldehyde
Authors: Ninagawa Akira , Nomura Ryoki , Matsuda Haruo
Published: July 2006

The reactions of several methyl substituted 4-chromanones, such as 4-chromanone (1a), 6-(1b), and 8-methyl-(1c), as well as 5,7-(1d) and 6,8-dimethyl-4-chromanone(1e) with formaldehyde were carried out in dioxane or mixed solutions of acetic acid and benzene or cyclohexane in the presence of sulfuric acid as a catalyst. The reactions involved an aldol condensation analogous to the Prins reaction, affording acetoxymethyl derivatives and 1,3-dioxanes. It was found that the formation of products was strongly influenced by the substituents on the 4-chromanones and solvents. In a mixed solution of acetic acid and benzene, 1b and 1e gave acetoxymethyl derivatives and 1,3-dioxanes, 1a and 1c only 1,3-dioxanes, and 1d a resinous substance. In a dioxane solution, 1b and 1e gave 1,3-dioxanes, while 1c gave a polymer. Bromination of 1e in 35 and 96% sulfuric acids gave 3- and 5-bromo-6,8-dimethyl-4-chromanones, respectively. The acid-catalyzed reactions were compared with those in 96% sulfuric acid on the basis of the duterium exchange rates of 4-chromanones.
Preparation of N-Acetylmuramyl-l-[U-14C]alanyl-d-isoglutamine via a Novel Synthetic Route
Authors: Kusumoto Shoichi , Ikenaka Kazuhiro , Shiba Tetsuo
Published: July 2006

For the investigation on the action mechanism of immunoadjuvant active N-acetylmuramyl-l-alanyl-d-isoglutamine, its labeled compound, i.e.,  N-acetylmuramyl-l-[U-14C]alanyl-d-isoglutamine was synthesized. For this purpose, an entirely novel synthetic route for the muramyl dipeptide was exploited using cold materials and applied to the preparation of the labeled compound. A convenient synthetic procedure of isoglutamine derivatives is also described.
Synthesis of Some Naturally Occurring Acetylchromenes
Authors: Chand Jain Amolak , Khazanchi Rajesh , Kumar Ashwani
Published: July 2006

2,4-Dihydroxy-5-methoxyacetophenone on treatment with 3-chloro-3-methyl-1-butyne in the presence of K2CO3, KI, and DMF yielded its 4-(1,1-dimethyl-2-propynyl) ether (2) and the naturally occurring 6-acetyl-5-hydroxy-8-methoxy-2,2-dimethylchromene (3). More of the chromene (3) could be obtained by the thermal cyclisation of the acetophenone (2). Methylation of 3 yielded another natural chromene. 4-Hydroxy-3-methoxyacetophenone, on similar treatment with 3-chloro-3-methyl-1-butyne, gave directly natural 6-acetyl-8-methoxy-2,2-dimethylchromene. 2,3,4-Trihydroxy-5-(3-methyl-2-butenyl)acetophenone, on cyclodehydrogenation followed by methylation with 1 mol of dimethyl sulfate, yielded natural ripariochromene-A. Further methylation provided methylripariochromene-A.
Design and Performance of the Air–Propane Nebulizer Burner for Atomic Absorption Spectrometry
Authors: Tsujino Ryuzo , Ogawa Akira , Musha Soichro
Published: July 2006

A new air–propane nebulizer burner, by the use of which the sensitivity and precision for atomic absorption measurements was approximately equal to those with an air–hydrogen nebulizer burner, has been developed. The flame with this burner has other characteristic features, such as low auditory noise, high stability, and low radiation noise in the OH band.
Dissolution of Metallic Copper in Ethylenediaminetetraacetate Solution in the Presence of Hydrogen Peroxide
Authors: Ohzeki Kunio , Takeuchi Koji , Kambara Tomihito
Published: July 2006

A 50 mg portion of metallic copper (100 mesh) placed in 50 ml of a neutral solution containing 0.1 mol dm−3 ethylenediaminetetraacetate (EDTA) was quantitatively dissolved within 20 min at 50 °C after the addition of a small amount of hydrogen peroxide, resulting in blue coloration of the copper(II)–edta complex.
Study of Metal–Polycarboxylate Complexes Employing Ion-selective Electrodes. III. Complex Formation between Maleic Acid Copolymers and Bivalent Transition Metal Ions
Authors: Yamashita Fumitaka , Komatsu Tsuyoshi , Nakagawa Tsurutaro
Published: July 2006

The complex formation of bivalent transition metal ions, Mn(II), Co(II), Ni(II), Cu(II), and Zn(II), with copoly(maleic acid–ethylene) and copoly (maleic acid-styrene) in aqueous solution was studied by potentiometric titration at 25 °C and the ionic strength of 0.1. The systems containing copper(II) ions were investigated by potentiometry employing the copper(II) ion-selective electrode. The titration curves of the bivalent metal–copoly(maleic acid–ethylene) systems were situated in a lower pH region than in the absence of the metal ions. The complex formed involves two carboxylate groups: primary and secondary. The equilibrium constant of the copper(II) complex was estimated to be 10−2.6. In copoly (maleic acid–styrene) systems, however, the titration curves in the absence and presence of bivalent metal ions overlapped partly in the first neutralization step. From the potentiometric results employing the ion-selective electrode, it was observed that the concentrations of copper(II) ions decrease slightly in the region of overlap. This anomalous behavior is due to the acid dissociation influenced by the conformational transition, including the effect of the side groups of the polymers.
Perturbation Calculation of Spin Densities in π-Electron Radicals
Authors: Hamano Hidekazu , Kondo Hiroshi
Published: July 2006

The unrestricted Hartree-Fock perturbation technique was applied to the calculation of spin densities in many hydrocarbon radicals. The method is similar to that of McLachlan but contains partly the SCF and projection procedures. The results agree with the more rigorous SCF ones.
Solubilities and Rates of Dissolution of Diaspore in NaOH Aqueous Solutions
Authors: Chang Byong-Tae , Pak Li-Hye , Li Yu-Suk
Published: July 2006

The solubility of diaspore (α-Al2O3·H2O or α-AlOOH) has been measured in NaOH aqueous solutions from 523.15 K to 598.15 K, and at concentrations of Na2O up to 150.7 g/l. In order to evaluate the equilibrium constant, K2°=(aAlO2−·aH2O)⁄aOH−, for the dissolution equilibrium of diaspore AlOOH(s)+OH−(l)=AlO2(l)+H2O(l), two methods have been applied to the solubility data. In the first method, analogous to the method previously applied to the dissolution equilibria of gibbsite, bayerite and beohmite, the values of K2 at relatively low concentrations of NaOH were extrapolated to zero NaOH concentrations. The temperature dependence of K2° was expressed as logK2°=−(2500⁄T)+4.45. The second method was based on the extended Debye-Hückel theory for the variation in the activity coefficients of AlO2−, OH−, and H+ ions with ionic strength at any temperature, that is, the value of the solubility product, K1°=aH+·aAlO2−, was obtained at a given temperature by extrapolating values of K1 equal to (mH+mAlO2−), to zero ionic strength. According to the second method, K2° was expressed as a function of the temperature: logK2°=−(1600⁄T)+2.52 when A=2.0 or logK2°=−(1550⁄T)+2.48 when A=1.5, where A is a parameter. From kinetic analysis of the dissolution rate of diaspore in NaOH solution, the rate constants per unit surface area of diaspore were found to be 0.31, 0.45, and 0.68 m−2 h−1 at 548.15, 573.15, and 598.15 K, respectively.
Polymer Effects under Pressure. III. Hydrolysis of Normal Alkyl Acetate Catalyzed by Dodecyl Hydrogensulfate Micelle
Authors: Taniguchi Yoshihiro , Inoue Osamu , Suzuki Keizo
Published: July 2006

Measurements of the rates of hydrolysis of methyl, ethyl, propyl, and butyl acetates have been made to 2 kbar in water catalyzed by dodecyl hydrogensulfate (DSA) micelle at 40 °C. The rate of hydrolysis decreases with compression up to approximately 1 kbar and then increases above 1 kbar; methyl acetate differs in these respects. The inversion phenomenon under pressure has been explained by the incorporation of both the H3O+ ion and ester molecules into the micellar phase. The observed value of the over all activation volume at 1 atm ΔV* is −5.3±1 cm3/mol for methyl, 0.40±1 cm3/mol for ethyl, 9.7±1 cm3/mol for propyl, and 20±1 cm3/mol for butyl acetate, respectively. From the activation volumes of HCl and DSA micellar catalysts, the volume change accompanying the incorporation of the esters into the micellar phase ΔΔVmicelle, has been estimated to be 4.0±1 cm3/mol for methyl, 9.8±1 cm3/mol for ethyl, 18.7±1 cm3/mol for propyl, and 27.9±1 cm3/mol for butyl acetate, respectively. The values above have been explained in terms of the contribution to the hydrophobic interaction between the ester molecule and the micelle.
Deuteration Kinetics of Tyrosine by Means of Fluorescence Measurement
Authors: Nakanishi Mamoru , Tsuboi Masamichi
Published: July 2006

When tyrosine was rapidly transferred from water into deuterium oxide medium by means of a stopped-flow device, a time-dependent change in the fluorescence intensity at 305 nm (excited at 275 nm) has been observed. The rate constant (ke) was found to be 116 s−1 at pH 5.8 and 14 °C. This ke value has been attributed to the rate constant of the O1H→O2H reaction of the phenolic OH group, on the basis of similar fluorescence examinations on phenol, anisole, glycyl-l-tyrosine, and Nα-acetyl-N-methyl-l-tyrosinamide as well as on the basis of a stopped-flow ultraviolet absorption study of tyrosine. The stopped-flow fluorometry has been applied to a study of tyrosine residues in yeast 3-phosphoglycerate kinase.
On the Normal Modes of Vibration in the Uracil Residue—The Use of 15N-Isotope Effects
Authors: Nishimura Yoshifumi , Haruyama Hideyuki , Nomura Kimiko , Hirakawa Akiko Y , Tsuboi Masamichi
Published: July 2006

β-Uridine-5′-phosphoric acid-15N2 has been prepared from 15N-RNA of baker’s yeast which was grown in (15NH4)2SO4 as the sole nitrogen source. Its Raman spectrum has been observed both in 1H2O and 2H2O solutions. On the basis of the observed 15N isotope effects on the Raman spectra and on the basis of other data previously obtained, normal modes of vibration have been discussed for six Raman bands of the uracil residue that are considered to be in resonance with its electronic transition at 260 nm. The result has led to a conclusion that C5=C6 is longer and C4–C5 is shorter in the excited electronic state Ã (260 nm) than those in the ground electronic state \~{X}.
Studies of Inorganic Ion Exchangers. IV. Ion Exchange Equilibrium between Titanium(IV) Bis(hydrogenphosphate) and NaCl–KCl Aqueous Solution
Authors: Kobayashi Etsuro
Published: July 2006

In order to develop an inorganic ion exchanger, ion exchange equilibriums between titanium(IV) bis(hydrogenphosphate) and NaCl–KCl aqueous solution have been investigated together with the possibility of separation of Na and K ions. A suitable quantity of Ti(HPO4)2·H2O (monohydrate), or Ti(HPO4)2 (anhydrate) was added to a fixed volume of the mixed solution of 0.1 M NaCl with 0.1 M KCl at various ratios. The Na and K ions in the equilibrium solution were determined, and the mole fractions of the ions distributed in the liquid and solid phases estimated. When 0.1 or 0.5 g of the monohydrate were added to 10 ml of each initial solution, the sum of the ion exchange capacities for Na and K ions was approx. 0.1–0.3 meq/g. When 0.1 g of the anhydrate were added to 10 ml of each of the initial solutions, the pH of the final solutions showed values in the range of 1.6–1.9. With the mole fractions of KCl/(NaCl+KCl) above 0.5 in the initial solution, only 2.5–3.5 meq/g of the K ion adsorbed. With an excess (0.5 g exchanger to 10 ml soln) of the anhydrate, all K ions and a part of Na ions were removed together from the solution with the mole fractions of KCl/(NaCl+KCl) being in a range of 0–0.8. The K ion could be effectively separated, when a suitable amount of the anhydrate was added to a solution containing approx. an equimole of NaCl and KCl; however, the elution of K ion with HCl could not be eased by this static method.
Preparation, Optical Resolution, Racemization, and Ligand Isotopic Exchange of Tris(1,3-diphenyl-1,3-propanedionato)germanium(IV) Perchlorate in Acetonitrile
Authors: Ueno Fumio B , Nagasawa Akira , Saito Kazuo
Published: July 2006

Tris(1,3-diphenyl-1,3-propanedionato)germanium(IV) [Ge(bzbz)3]+ was prepared as crystalline perchlorate, and resolved by the crystallization of its salt with hydrogen (R,R)-O,O-dibenzoyltartrate. The patterns of UV and circular dichroism spectra are very similar to those of [Si(bzbz)3]ClO4. The racemization of the Δ-[Ge(bzbz)3]ClO4 was studied kinetically in acetonitrile at 40–60 °C to find the rate law: Rate=krac[complex], where krac=9.86×10−5 s−1 at 50 °C. The activation parameters (ΔH\eweq=99±2 kJ mol−1 and ΔS\eweq=−17±2 J K−1 mol−1) are very similar to those of tris(acetylacetonato)germanium (IV) complex. Compared with the rate of ligand isotopic exchange, the racemization should proceed via intramolecular mechanism. The steric effect coming from the substituents on the chelate ring should play an important role in determining the racemization rate.
Phase Relation in the System PbO–PbGeO3
Authors: Hirota Kazushi , Sekine Toshimori
Published: July 2006

Phase relations in the system PbO–PbGeO3 were determined using both the quenching and DTA techniques. Two new lead germanate phases Pb5GeO7 and Pb11Ge3O17 were found to be stable. It was found that the Pb5GeO7 melts incongruently at 738 °C to PbO plus liquid, whereas the Pb11Ge3O17 decomposes into Pb5GeO7 plus Pb3GeO5 at 728 °C. The compounds Pb3GeO5, Pb5Ge3O11, and PbGeO3 were identified as congruently melting compounds, in accordance with previous investigations. Some other compounds, such as Pb6GeO8, Pb4GeO6, and Pb3Ge2O7, which have been reported previously could not be confirmed as stable phases.
Preparations and Characterization of Cycloruthenated Complexes Derived from 1-Phenylpyrazole, 2-Phenylpyridine, and Benzo[h]quinoline
Authors: Hiraki Katsuma , Obayashi Yayoi , Oki Yoko
Published: July 2006

A pale yellow solution, prepared from RuCl3·3H2O and carbon monoxide in 2-methoxyethanol, reacted with 1-phenylpyrazole (Hphpz), 2-phenylpyridine (Hphpy), and benzo[h]quinoline (Hbzqn) to give new chlorobridging dinuclear cycloruthenated complexes, [{RuCl(C∼N)(CO)2}2] (C∼N=cycloruthenated moiety). These complexes reacted with Tl(acac) (acac=acetylacetonato ligand), γ-picoline (pic), and triphenylphosphine resulting in the break-down of the chloro-bridging bond of the complexes, and afforded new mononuclear cycloruthenated complexes, [Ru(acac)(C∼N)(CO)2], [RuCl(C∼N)(CO)2(pic)], and [RuCl(C∼N)(CO)n-(PPh3)3−n] (n=2 for phpz, and n=1 for phpy and bzqn), respectively. The complexes prepared in this study were characterized by IR, 1H-NMR, and mass spectroscopies.
The Absolute Configuration and Circular Dichroism of (+)240CD-[(2S,7S)-2,7-Dimethyl-3,6-diazaoctane-1,8-diamine]platinum(II) Chloride Dihydrate
Authors: Nakayama Yasuji , Ooi Shun’ichiro , Kuroya Hisao
Published: July 2006

The title compound was synthesized and characterized by means of absorption, circular dichroism, and its NMR spectra as well as X-ray structure analysis. The crystals are monoclinic, with a P21 space group, a=9.175(3), b=12.423(5), c=7.434(3) Å, β=108.1(4)°, and Z=2. The structure was determined from the diffractometcr data and refined by a least-squares method to R=0.041 for 1732 observed reflections. The Pt atom has an essentially planar coordination with 4 N atoms. The disposition of the four donor atoms is not rectangular, but trapezoidal; it is, moreover, slightly tetrahedral. The quadridentate ligand forms three 5-membered chelatc rings with the Pt atom. The two terminal rings are of a δ asymmetric envelope conformation, while the middle ring has a λ symmetric skew conformation. Both of the secondary N atoms possess a R configuration. The complex ion has a pseudo-two-fold axis by which the two terminal rings are related to each other. The circular dichroism spectrum reflects mainly the conformations of the 5-membered chelate rings. The features of the absorption and circular dichroism spectra are discussed on the basis of the geometry of the PtN4 chromophore.
Temperature Dependence of the Optical Resolution and Solubility Isotherm of Bis(ethylenediamine)oxalatocobalt(III) (1R,3S,4S,7R)-3-Bromocamphor-9-sulfonate
Authors: Fuyuhiro Akira , Yamanari Kazuaki , Shimura Yoichi
Published: July 2006

The determination of solubility isotherm of a ternary system, Λ-[Co(ox)(en)2](d-C10H14OBrSO3)–Δ-[Co(ox)(en)2](d-C10H14OBrSO3)–H2O, between 5 and 25 °C, revealed that the resolving agent (1R,3S,4S,7R)-3-bromocamphor-9-sulfonate ion is applicable to the optical resolution of the [Co(ox)(en)2]+ ion below 19 °C from the viewpoint of solubility in water, in spite of the formation of a pseudo racemic compound, Λ-[Co(ox)(en)2]·Δ-[Co(ox)(en)2] (d-C10H14OBrSO3)2·2H2O.
The Regioselective C-Hydroxyalkylation of 1,3-Diphenyl-1,3-propanedione with Halo Alcohols, Involving Intramolecular Alcoholysis: the Synthesis of Oxoalkyl Esters
Authors: Tsutsumi Hideo , Inoue Kimio , Ishido Yoshiharu
Published: July 2006

The reaction of 1,3-diphenyl-1,3-propanedione (1) with 2-chloroethanol (2) or 3-chloro-1-propanol (3) was performed in the presence of potassium carbonate and sodium iodide as an improved procedure for regioselective C-hydroxyalkylation, involving intramolecular alcoholysis; the effects of the solvents, the temperature, and the amounts of potassium carbonate and sodium iodide were also investigated. The reaction with 2 afforded 3-benzoylpropyl benzoate (4) (ca. 70% yield), together with 2-benzoylmethyl-2-phenyl-1,3-dioxolane (5) (ca. 15% yield). The reaction with 3, on the other hand, gave 4-benzoylbutyl benzoate (92–94% yield); the corresponding 1,3-dioxane derivative was detected only in a trace. Moreover, the reaction of 1 with 2-hydroxyethyl tosylate was similarly performed, but the yields of both 4 and 5 were unexpectedly low.
Michael Addition of 4H-Cyclopenta[def]phenanthrene to 9,9′-Bifluorenylidene and the Related Reactions
Authors: Kimura Takao , Minabe Masahiro , Suzuki Kazuo
Published: July 2006

The compound 9-(4H-cyclopenta[def]phenanthren-4-yl)-9,9′-bifluorene was synthesized by the Michael addition of 4H-cyclopenta[def]phenanthrene to 9,9′-bifluorenylidene and also by other reactions. In addition, five kinds of trimers which consisted of 4H-cyclopenta[def]phenanthrene and fluorene were obtained by the same reactions. The conformation of these trimers is assigned to be the gauche-gauche form.
The Total Synthesis of (+)-Totarol and (+)-Podototarin
Authors: Matsumoto Takashi , Suetsugu Akira
Published: July 2006

The Grignard reaction of 7-methoxyphthalide with methylmagnesium iodide, followed by acetylation and dehydration, gave 3-acetoxymethyl-2-isopropenylanisole which, on catalytic hydrogenation, afforded 3-acetoxymethyl-2-isopropylanisole. This was then converted into (2-isopropyl-3-methoxybenzyl)triphenylphosphonium chloride (8) via 3-hydroxymethyl-2-isopropylanisole and 3-chloromethyl-2-isopropylanisole. The Wittig reaction of (R)-(−)-α-cyclocitral with 8 in the presence of butyllithium afforded the corresponding styryl derivative, which was converted into the dihydro compound (19) by partial catalytic hydrogenation. The intramolecular cyclization of 19 gave (+)-totaryl methyl ether (20) along with its cis-isomer. The methyl ether 20 was finally demethylated with boron tribromide to give (+)-totarol (1), which was further characterized as its acetate. Since the conversion of (+)-1 into (+)-podototarin has already been reported, the present work can be regarded as the total synthesis of natural (+)-podototarin.
The Total Synthesis of (+)-Taxoquinone, (−)-7α-Acetoxyroyleanone, (−)-Dehydroroyleanone, (−)-Horminone, (−)-7-Oxoroyleanone, and (+)-Inuroyleanol
Authors: Matsumoto Takashi , Harada Shogo
Published: July 2006

Methylation of 12-benzoyloxyabieta-8,11,13-trien-11-ol with methyl iodide afforded 11-benzoyloxy-12-methoxyabieta- and 12-benzoyloxy-11-methoxyabieta-8,11,13-triene (9). Oxidation of the latter product with chromium trioxide, followed by sodium borohydride reduction and acetylation, gave 7β-acetoxy-12-benzoyloxy-11-methoxyabieta-8,11,13-triene (17) and its 7α-acetoxy isomer (18) in a ratio of ca. 5 : 1. On the other hand, treatment of 9 with lead tetraacetate produced 17 and 18 in a ratio oi ca. 1 : 2. The 7β-acetate (17) was then oxidized with chromium trioxide and the resulting p-quinone derivative was hydrolyzed with aqueous sodium hydroxide to give taxoquinone (1), which on dehydration gave dehydroroyleanone. Similarly, the 7α-acetate (18) was converted into horminone (4) via the p-quinone derivative, which was treated with aqueous sodium hydrogencarbonate to give 7α-acetoxyroyleanone. Oxidation of 4 with manganese dioxide afforded 7-oxoroyleanone. Methylation of 1 with diazomethane, followed by oxidation with a chromium trioxide-pyridine complex, afforded 12-methoxyabieta-8,12-diene-7,11,14-trione, which on reduction with sodium dithionite gave inuroyleanol.
Kinetics of the Reaction of α-Chloro Aliphatic Acids with Aqueous Ammonia
Authors: Ogata Yoshiro , Kawasaki Atsushi , Sawaki Yasuhiko , Yamauchi Yuya
Published: July 2006

The kinetics of the reaction of α-chloro aliphatic acids (CAA’s) with aqueous ammonia to form the corresponding α-amino acids and α-hydroxy acids have been studied by measuring the produced chloride ion. The observed rate for CAA’s having COOH on a s-C (s-CAA’s) is expressed as: v=(k1+k2[NH3]ex)[CAA], while the rate for CAA having COOH on a t-C (t-CAA): v=k1[CAA], These results together with previous observations indicate that the mechanism changes with substrate, i.e., pure SN2 type for chloroacetic acid to pure SN1 type for α-chloroisobutyric acid. The exclusion of α-lactone mechanism and the effect of carboxylato group are discussed. The reactivity of ammonia toward α-chloro aliphatic acids is as twice as that of hydroxide ion.
Solvolysis in Carboxamides. V. Solvolytic Elimination of threo-1-Methyl-2-phenylpropyl Brosylate in N,N-Dimethylacetamide. Kinetic, Product, and Deuterium Tracer Studies
Authors: Saito Seiki , Doihara Kenji , Moriwake Toshio , Okamoto Kunio
Published: July 2006

Solvolysis of a series of ring substituted threo-1-methyl-2-phenylpropyl brosylates has been carried out in N,N-dimethylacetamide (DMA) as solvent. Hammett treatment of the rate data indicated that the DMA solvolysis of the unsubstituted brosylate (1c) falls into the category of ks pathway (100%). In order to gain further information of the nature of the ks pathway, the DMA solvolysis of 1c or 1c-2-d (labeled at C(2)) has been conducted. The product distribution, effect of water content on it, the composition and deuterium distribution of recovered brosylate, kinetic isotope effect, and the deuterium distribution of product have been investigated. The products consisted of the olefins ((E)- and (Z)-2-pheny1-2-butenes, and 2- and 3-phenyl-1-butenes), and, in the presence of water in DMA, the carboxylates (erythro- and thero-1-methyl-2-phenylpropyl acetates) and the small amount of diastereomeric alcohols. The major product was (Z)-2-phenyl-2-butene, indicating the occurrence of anti-E1 process. The deuterium was substantially scrambled in each product. These findings suggest that the reaction proceeds through tight ion-pair and subsequent processes such as anti-E1, 2,1-phenyl and -hydride shifts, solvent capture, and threo-erythro interconversion take place competitively. In view of a substantial extent of intervention of such rearrangement, the involvement of nucleophilic solvent assistance is thought to be less probable in this ks process.
Studies on Unusual Amino Acids and Their Peptides. X. The Convenient Synthesis of t-Leucine and the Optical Resolution of the N-Benzyloxycarbonyl Derivative
Authors: Miyazawa Toshifumi , Takashima Katsumi , Mitsuda Yoshikazu , Yamada Takashi , Kuwata Shigeru , Watanabe Hiroshi
Published: July 2006

t-Leucine has been conveniently prepared on a large scale from the phenylhydrazone of trimethylpyruvic acid, which was readily obtained as a precipitate from the oxidation of pinacolone. The N-benzyloxycarbonyl derivative of Dl-t-leucine has been resolved with quinine and quinidine in ethanol.
Effect of Etching on Intrinsic and Dye-sensitized Photocurrents in Zinc Oxide Electrodes
Authors: Matsumura Michio , Nomura Yoichi , Tsubomura Hiroshi
Published: July 2006

The photoelectrochemical behavior of sintered zinc oxide electrodes was studied. The intrinsic photocurrent, generated by ultraviolet illumination of the zinc oxide electrode, significantly diminished by grinding the electrode surface with an abrasive, and was restored by etching in 2 M(M= mol dm3)HCl for ca. 120 s. The dye-sensitized photocurrent caused by rose bengal was also lowered by grinding, but the effect was not as large as in the case of the intrinsic photocurrent, and the photocurrent was restored in a much shorter time of etching. The dye-sensitized photocurrent for an insufficiently etched electrode was enhanced by addition of a reducing agent, e.g., hydroquinone or allylthiourea. However, no enhancement was observed for a well etched electrode. The results, together with the luminescence and reflection spectra of zinc oxide, were discussed by means of models for the semiconductor electronic bands.
Direct Synthesis of 2,2-Diaryl-3-methyl-2,3-dihydrobenzothiazoles from 3-Methyl-2,3-dihydrobenzothiazole-2-thione and Some Mechanistic Aspects
Authors: Akiba Kin-ya , Shiraishi Hiroaki , Inamoto Naoki
Published: July 2006

Reactions of 3-methyl-2,3-dihydrobenzothiazole-2-thione (1) and 3-methyl-2-(methylthio)benzothiazoliumiodide with Grignard reagents gave 2,2-disubstituted 3-methyl-2,3-dihydrobenzothiazole (2) as a major product as well as 2,2′-disubstituted 3,3′-dimethyl-2,2′,3,3′-tetrahydrobi(2-benzothiazolyl) (3). Reactions of 1 with organolithiums gave 2 as a major product. The results demonstrate that the formation of 3 is due to the presence of transition metals as an impurity in magnesium.
Association and Photolysis of 1-Benzyl-4-methoxycarbonylpyridinyls
Authors: Ikegami Yusaku , Kubota Shozo , Watanabe Hidetoshi
Published: July 2006

1-Benzyl- and 1-(4-methylbenzyl)-4-methoxycarbonylpyridinyl radicals have been prepared by reducing the corresponding pyridinium iodides with sodium amalgam. Hyperfine structures of the ESR spectra were analyzed. The radicals were decomposed photochemically with visible light in the region 380–440 nm in order to generate the intermediate benzyl radicals which were identified spectroscopically at 77 K. Association of each radical at low temperature forms a diamagnetic radical dimer, which is transformed by irradiating the solution with 440–470 nm light into the triplet dimer with zero-field parameters, D=ca. 0.017 cm−1 and E≈O. Another radical, 1-(4-nitrobenzyl)-4-methoxycarbonylpyridinyl, is unstable at room temperature.
Anodic Oxidation of N,N-Dimethyl-m-toluidine at a Platinum Electrode in an Acetonitrile Solution
Authors: Yasukouchi Kazuo , Taniguchi Isao , Yamaguchi Hiroko , Tanoue Tatsuya
Published: July 2006

The electrochemical behavior of N,N-dimethyl-m-toluidine (DMMT) in an acetonitrile solution at a Pt electrode was investigated. By controlled-potential oxidation at 0.65 V (vs. Ag/0.01 mol dm−3 AgClO4), the dihydro compound (I-a), which had been considered to be an intermediate in the reaction forming benzidine, was probably obtained. I-a was gradually converted to N,N,N′,N′-tetramethyl-2,2′-dimethylbenzidine (TMMB) in the solution within several hours. I-a was easily converted to TMMB by the cathodic re-reduction at −0.9 V or by adding either pyridine or water; this reaction pathway is useful for the synthesis of TMMB. Preliminary mechanistic information on the anodic oxidation of DMMT is also given by cyclic and ring-disk electrode voltammetry, current-reversal chronopotentiometry, and controlled-potential coulometry. The proposed reactions are: A–e→A\underset.+, A\underset.++A\oversetk→A-A\underset.+, and A-A\underset.+–e→DH22+, where A and A\underset.+ are, respectively, DMMT and its cation radical, DH22+ is the dihydro compound (I-a), and k is the rate constant of the coupling reaction (ca. 5×103 dm3 mol1 s1). TMMB is formed by: DH22++2e(or 2Py)→D+H2(or 2PyH+), where D is TMMB and Py is pyridine.
HeI and HeII Photoelectron Study of N2O4
Authors: Nomoto Katsunori , Achiba Yohji , Kimura Katsumi
Published: July 2006

A 304 Å HeII photoelectron spectrum of N2O4 in the gaseous phase has been deduced in the region up to 29 eV from a HeI spectrum of NO2–N2O4 mixture obtained with a nozzle beam technique, indicating three new maxima in the region between 20 and 29 eV. A 584 Å Hel spectrum of N2O4 was also obtained here. From a comparison of the HeI and HeII spectra of N2O4 below 20 eV, it was confirmed that two ionization bands exist at 16.5 and 18.2 eV which appear as shoulders in the HeII spectrum. At least fourteen ionization bands have been identified from the HeII spectrum in the region studied. The thirteen bands below 24 eV have been assigned on the basis of a recent Green’s function study of von Niessen et al.
Dry Ozonation of Friedelane and Friedelin
Authors: Akiyama Eri , Tada Masahiro , Tsuyuki Takahiko , Takahashi Takeyoshi
Published: July 2006

Dry ozonation of friedelane afforded 18β,19β-epoxyfriedelane, 19-oxofriedelane, 16-oxofriedelane, 21-oxofriedelane, friedelin, and a new compound, 15-oxofriedelane. Friedelin, on dry ozonation, gave 3,16-dioxofriedelane, 3,19-dioxofriedelane, and new compounds, 18β,19β-epoxyfriedelan-3-one and 3,15-dioxofriedelane. It was shown that the oxidation occurred at D and E rings regioselectively in the dry ozonation.
Complexation Equilibria of Vanadium(V) with 8-Quinolinolate in Aqueous Solutions
Authors: Yuchi Akio , Yamada Shinkichi , Tanaka Motoharu
Published: July 2006

The complexation equilibria of vanadium(V) with 8-quinolinolate ion(ox−) were investigated spectrophotometrically. Depending upon the acidity of the solution various 1 : 1 and 1 : 2 complexes are formed: VO3ox2−, VO3Hox−, VO2ox, and VO2ox2−. The formation and protonation constants of these complexes are discussed in terms of their structures.
Circular Dichroism and Stereochemistry of Tetranuclear Cobalt(III) Complexes of Hexol Type. I. Dodecaammine-hexa-μ-hydroxotetracobalt(III) Ion, [Co{(OH)2Co(NH3)4}3]6+
Authors: Kudo Tomikatsu , Shimura Yoichi
Published: July 2006

From the circular dichroism spectra of optically active dodecaammine-hexa-μ-hydroxo-tetracobalt(III) ion, (+)589-[Co{(OH)2Co(NH3)4}3]6+, measured in the visible and ultraviolet region in several solvents such as 0.01M-HCl and 0.17M-Na2SeO3, the d–d transitions of the complex are assigned in consideration of the ion-pairing effect. The absolute configuration of (+)589 isomer is assigned as Δ based upon a negative sign of the Ea component for the CoO6 chromophore. The circular dichroism change by the ion-pairing is attributed to the vicinal effect of chiral oxygen centers stereospecifically produced by the ion-pair formation, and the importance of the oxygen chirality is discussed on the basis of the time-course of circular dichroism change in the solutions.
Synthesis of a Protected Tridecapeptide Corresponding to Positions 17–29 of Human Lysozyme
Authors: Yoshimura Shoko , Shimonishi Yasutsugu
Published: July 2006

For a semi-synthesis of human lysozyme by coupling its natural fragment with synthetic peptides, a protected tridecapeptide corresponding to positions 17–29 of the enzyme was prepared from three protected peptide fragments (II, VI, and XI) by the conventional method in pure form on the basis of analyses.
Syntheses of Capreomycin Analogs in Relation to Their Antibacterial Activities
Authors: Nomoto Shinya , Shiba Tetsuo
Published: July 2006

Six analogs of an antituberculous antibiotic capreomycin were synthesized in order to clarify the structure-activity relationship, especially with regard to the significance of the β-amino group in α,β-diaminopropionic acid residue as well as the position of linkage of the branch residue, β-lysine, to the cyclic peptide moiety. All the synthetic products were found to have the same conformations in solution as those of the natural antibiotics in terms of NMR spectra. It was found from their antibacterial activities that an amino group located at β-position of the α,β-diaminopropionic acid residue adjacent to ureidodehydroalanine residue remarkably strengthens the biological activity, and that the position of a branch does not significantly influence the antibacterial potency.
Preparation of Model Polymers for Visual Pigment and Spectral Changes
Authors: Nanasawa Masato , Kamogawa Hiroyoshi
Published: July 2006

N-(8′-Apocarotene-8′-ylidene)butylamine (Bu-SB) has been protonated with amino acid derivatives in aqueous solution and the absorption maxima of the protonated products observed at 500 nm. Copolymers (from Nα-methacryloyl-l-lysine methyl ester and α-methyl N-methacryloyl-l-glutamate) bearing long conjugated double bonds as a side chain have been synthesized for the simulation of rhodopsin. The absorption spectra shifted to longer wavelengths, and the absorbances amounted to 4–8%, based on the maximum peaks.
The Regioselective Amino-exchange Reaction of β-Amino Conjugated Enones
Authors: Kashima Choji , Yamamoto Yasuhiro
Published: July 2006

By heating with various amines, the amino-exchange reaction of β-amino conjugated enones was regioselectively accomplished on β-carbon to give the corresponding β-amino conjugated enones. The resulting β-dialkylamino conjugated enones could then be used for the synthesis of β,β-disubstituted conjugated enones by treatment with Grignard reagents.
The Hydrogen-transfer Reaction of a Diazo Compound Catalyzed by a Cobalt Complex
Authors: Yoshino Kenji , Ohkatsu Yasukazu , Tsuruta Teiji
Published: July 2006

Acetophenone α-methylbenzylhydrazone was produced by the thermolysis of 1,1′-diphenylazoethane in the presence of a cobalt complex in benzene. In this reaction, the cobalt complex seemed to stabilize the radicals formed from the azo compound by the elimination of α-hydrogen. The stabilized radicals underwent 1,3-rearrangement to form acetophenone α-methylbenzylhydrazone. The driving force of this rearrangement is considered to be the nature of the cobalt atom, which prefers a bond formation with a more electronegative nitrogen atom to a carbon atom.
Temperature Effects on the Stereochemistry of the Solvolysis of trans-2,3-Diphenyloxirane
Authors: Inoue Masashi , Taguchi Yoshio , Sugita Toshio , Ichikawa Katsuhiko
Published: July 2006

The temperature effects on the stereochemistry of the acid-catalyzed ethanolysis of trans-2,3-diphenyloxirane were examined. The stereochemistry of the reaction became more retentive as the reaction temperature was raised. The reaction mechanisms are discussed, and it is concluded that concurrent reactions take place in the ethanolysis, one of them giving an inverted product, and the other, a retained one, and that the former reaction is caused by a nucleophilic attack of ethanol on the carbon of the conjugate acid of the epoxide, while the latter proceeds via an intermediate which has a carbonium-ion character.
Modified Preparation of Sodium Guaiazulenide and Reaction of the Reagent with 3-Formylguaiazulene
Authors: Kurokawa Shinji
Published: July 2006

As a modification for facilitating small-scale reactions, sodium N-methylanilinide was prepared from sodium hydride and N-methylaniline instead of by the usual method from sodium, N-methylaniline, and naphthalene (as assistant). Sodium N-methylanilinide, made by this procedure, was successively converted to sodium guaiazulenide, the formation of which was checked by tracing known reactions. The reaction of the reagent with 3-formylguaiazulene was also studied, and found to yield 4-substituted 2-formyl-1,4-dihydroguaiazulene and 6-substituted 2-formyl-3,6-dihydroguaiazulene. In this case, nucleophilic addition of guaiazulenide anion occured not at the carbonyl group but at the 6- and 8-positions of the seven-membered ring of formylguaiazulene, accompanied by formyl group and hydrogen migrations.
A Highly Stereoselective Synthesis of Trisubstituted Ethylenes from α-Trialkylsilyl Ketones
Authors: Obayashi Michio , Utimoto Kiitiro , Nozaki Hitosi
Published: July 2006

A novel procedure for preparing trisubstituted ethylenes stereoselectively is based on the reaction of α-trialkylsilyl-substituted ketones with alkyllithium reagents and on the following highly discriminative elimination of the silyl and oxido (or hydroxyl) groups from the resulting adducts. The syn-elimination of both groups is observed under basic conditions, while the reaction proceeds in anti-fashion on acid treatment. Furthermore α-trimethylsilylated ketones are shown to be readily obtained from 2-trimethylsilyl-2,3-dialkyloxiranes. The reaction sequence is applied to the stereoselective synthesis of tetrahomonerol which has been obtained from the codling moth.
A Theoretical Treatment of the Difference in the Fragmentation of Urea and Acetamide
Authors: Takagi Tsutomu , Oiwa Masayoshi
Published: July 2006

The difference in the hydrogen migration in urea and acetamide under electron impact has been discussed from the standpoint of the all-valence electron semi-empirical SCF-MO theory (CNDO/2). The features of the molecular ion in the ground state and the hydrogen-migration models for both compounds were estimated based on the variations in the total and the partitioned energies. The variation in the total energy with the hydrogen migration in urea was smaller than that in acetamide. Moreover, the bonding interaction between carbon and nitrogen becomes weak; the cleavage of the migrated molecular ion to NH3 was predicted. On the other hand, the weak bonding interaction between carbon and carbon in acetamide does not change through the migration of hydrogen. It is predicted that the α-cleavage in the C–C bond will occur in preference to the migration of hydrogen. Finally, in acetamide, it was found that the possibility of the migration of hydrogen is lower than that in urea, judging from the variations in the total and the partitioned energies.
Electron Spin Resonance Study of the Pyramidal Geometry around the Tervalent Carbon Atom of the Bicyclo[2.1.1]hexan-5-yl Radical
Authors: Kawamura Takashi , Hayashida Shigeru , Yonezawa Teijiro
Published: July 2006

The bicyclo[2.1.1]hexan-5-yl and the 5-deuteriobicyclo[2.1.1]hexan-5-yl radicals have been examined using ESR. A comparison of the spectra confirmed that geometry around C5 is pyramidal and showed highly stereoselective long-range spin-transfer from C5 to the endo proton on C6; a(H6endo)=28.22 and a(H6exo)=0.49 G. A potential curve for the out-of-plane bending motion of the C5–H5 bond, selected from the trial curves gave a reasonable simulation of the temperature dependence and isotope effects on a(H5) and a(H6endo). The curve has two minima with a relatively low barrier to inversion; the geometry of the C5–H5 bond bent in the exo direciton has been estimated as approximately 0.9 kcal/mol more stable than that with the C5–H5 bond located in the endo direction.
Studies on Biologically Active Pteridines. I. The Synthesis of 6-(1R)[and (1S)](1-Hydroxyethyl)- and 6-(1S)and (1S)]-(1,2-Dihydroxyethyl)-2-amino-4-hydroxypteridines
Authors: Sugimoto Takashi , Matsuura Sadao
Published: July 2006

2-Amino-4-hydroxy-6-[(1S)-1, 2-dihydroxyethyl] pteridine has been synthesized by the condensation of 2,4,5-triamino-6-hydroxypyrimidine and d-threose phenylhydrazone, followed by oxidation of the intermediate carried out by adding the condensate to a mixture of K3[Fe(CN)6], KI, and H2O2 in an acidic solution. The 6-(1R)-1,2-dihydroxyethyl isomer and the 6-(1R) [and (1S)] -1-hydroxyethyl analogues have also been synthesized in a similar way. By applying the present method, biopterin has been obtained in 28% yield.
Continuous Removal of Heavy Metals by the Lime Sulfurated Solution (Calcium Polysulfide) Process
Authors: Aratani Toshiro , Yasuhara Shigeki , Matoba Hitoshi , Yano Takeo
Published: July 2006

A continuous wastewater treatment system was developed for the Lime Sulfurated Solution Process which had already been tested in a batch, stirred tank and ascertained to be an effective chemical precipitation process. The removability of heavy metals was investigated with the continuous treatment system, consisting of a plant composed of H2S desorber, reactor, thickener, sand filter, and H2S desorber. The sulfide ion dissolved in treated water was desorbed as H2S by a mixed gas of air and CO2 and recycled in the reactor to precipitate heavy metals. It has been found that: (1) by the recycling use of H2S, the continuous treatment system can remove heavy metals with less coagulant than in the batch, stirred vessel, (2) desorption of the dissolved sulfide ion by the mixed gas decreases the sulfide ion concentration in the treated water below 0.2 ppb, and (3) the conditions for the removal of heavy metals can be detected immediately by a sulfide ion electrode meter.
On the Mechanism of Formation of Furotropones from (4-Halogeno-2-butenyloxy)tropones
Authors: Takeshita Hitoshi , Tajiri Kozo , Kouno Isao
Published: July 2006

Pyrolysis of 2-[(E)-4-bromo-3-butenyloxy]tropone and 2-[(E)-4-bromo-2-methyl-2-butenyloxy]tropone produced 3-methyl-3-vinyl-2,3-dihydro-8H-cyclohepta[b]furan-8-one and 3-isopropylidene-2,3-dihydro-8H-cyclohepta [b]furan-8-one, which established the involvement of 3,3-sigmatropy for furotropone formation.
Effect of Inorganic Additives on the Reactions of Isomeric Transition-Activated 80Br and 82Br in the Gaseous HBr–CH4 System
Authors: Kondo Kenjiro , Yagi Masuo
Published: July 2006

The effects of various inorganic additives with and without dipole moments on the product yield distributions have been examined in the CH4–H80mBr and CH4-H82mBr systems. Indications were that the ion-clusters formed in the reactions of IT-activated 80Br and 82Br play an important role in determining individual product yield distributions.
The Principle of Corresponding States at Elevated Pressure
Authors: Kubota Kenji , Ogino Kazuyoshi
Published: July 2006

The principle of corresponding states was examined at elevated pressure, and the validity of the assumption that the external degrees of freedom of the solution are given by linearity in the weight fraction of the components was examined without any model by use of the superposition method.