bluuebunny/crossref_metadata_2025 huggingface dataset:
Acyl Cyanide. V. The Synthesis of 1-Cyano-1-alkenyl Esters by the Reaction of Acyl Cyanides with Acid Anhydrides and Isocyanates
Authors: Oku Akira , Nakaoji Shigeru , Kadono Toshio , Imai Hideki
Published: July 2006

The reactions of enolizable acyl cyanides (acetyl, propionyl, and isobutyryl cyanide) with acid anhydrides (acetic, propionic, butyric, isobutyric, and benzoic anhydride) in the presence of a catalytic amount of tertiary amines (pyridine, lutidines, 4-(dimethylamino)pyridine) produced the corresponding 1-cyano-1-alkenyl carboxylates. In the reactions of propionyl cyanide, (Z)-1-cyano-1-propenyl carboxylates were formed predominantly over the (E)-isomers (isomer ratios Z⁄E were ca. 80/20). The reactions of the cyanides with isocyanates also gave the corresponding 1-cyano-1-alkenyl carbamates in moderate yields, and the acid-treatments of 1-cyano-2-methyl-1-propenyl phenylcarbamate induced its annelation into 3-phenyl-1,3-oxazolidine-2,4-dione derivatives.
Electronic State of Ethoxycarbonylnitrene Generated by α-Elimination under Two-phase Conditions
Authors: Sen\={o} Manabu , Namba Tomiyuki , Kise Hideo
Published: July 2006

The base decomposition of ethyl p-nitrophenylsulfonyloxycarbamate in organic-aqueous two-phase systems in the presence of cis- or trans-4-methyl-2-pentene and quaternary ammonium or phosphonium halides afforded both stereospecific and nonstereospecific addition products of ethoxycarbonylnitrene. The electronic state of the nitrene was analyzed on the basis of Skell’s hypothesis.
The γ-Ray Induced Oxidation of Cyclohexene in the Liquid Dinitrogen Oxide at −18 °C
Authors: Hirokami Shun-ichi , Wojnarovits Laszlo , Sato Shin
Published: July 2006

The γ-radiolysis of a cyclohexene–dinitrogen oxide mixture in the liquid phase at −18 °C has been studied and the results compared with that of the radiolysis of a cyclohexene–carbon dioxide mixture in the liquid phase.5) The oxidation reaction initiated by oxygen atoms produced in the direct radiolysis of dinitrogen oxide or carbon dioxide is common for both solutions, the products being cyclohexene oxide, cylohexanone, and cyclopentanecarbaldehyde. In the dinitrogen oxide solution, however, two other oxidation processes have to be considered in order to interpret the material balance of products and the formation of other oxygenated compounds: cyclohexanol, 2-cyclohexenol, and 2-cyclohexenone. A possible reaction mechanism is discussed.
The Substituent Effect. 14. The Solvolysis of 6- and 7-Substituted 1-(2-NaphthyI)ethyl Chlorides
Authors: Tsuno Yuho , Sawada Masami , Fujii Takahiro , Yukawa Yasuhide
Published: July 2006

Nine of the title compounds were synthesized, and their solvolysis rates were determined in 80%(v/v) aq acetone at 45 °C. The effects of the pi-donor substituents for each substituent position are shown to be excellently described in terms of inductive(I) and pi-electronic(Pi) effects by means of the LSFE equation (logk⁄k0=ρiσi+ρπ+σπ+), Just as with those in the 1-naphthyl systems. When those data are joined with all our substituent effects data for the phenyl, 4-biphenylyl, 2-fluorenyl, and 1-naphthyl systems under identical conditions, it is clear that the overall correspondence between the ρi values and Dewar’s simple-field-effect function (1⁄r) is satisfactory. On the other hand, the ρπ+ values appear to give slightly different responses (separate correlations for the 1- and 2-naphthyl systems) to the SCF-π charge difference values; this may be ascribed to the steric effects on the Pi effect in only the 1-naphthyl-solvolysis sets. Furthermore, the position constancy of the I effect (ρi,6−X−2⁄ρi,7−X−2=0.85) has been observed in the present solvolysis and the available data for dissociation of 2-naphthalenecarboxylic acids involving relatively weak Pi effects; the figure is in good agreement with the ratio of ρi,para⁄ρi,meta=0.85. Analogous results were also achieved by the same treatment to 2-benzo[b]thienyl reactivities. All the results are discussed with respect to the validity of the LSFE equation.
Conductometric Study of Ion-Ion and Ion-Solvent Interactions. I. Conductances of Silver Acetate in 0–50% (w/w) Methanol–Water Mixtures at 35 °C
Authors: Ananthaswamy J , Sethuram B , Navaneeth Rao T
Published: July 2006

Conductances of the solutions of silver acetate in 0 to 50% (w/w) methanol–water mixtures were measured at 35 °C. The association constants and molar conductances at infinite dilution were calculated using the Shedlovsky extrapolation technique and the Fuoss-Hsia equation with Fernandez-Prini coefficients. The logKA  vs. 1⁄D plot passes through the origin in accordance with the Denison-Ramsey theory of ion-pair formation. The results were interpreted in terms of the equilibrium between the solvent separated ion-pairs (SSIP) and contact ion-pairs (CIP).
Preparation and Characterization of Complexes of Dichlorobis(cyclopentadienyl)zirconium(IV) with Bidentate, Terdentate, and Quadridentate Schiff Bases
Authors: Gupta Gopal , Sharan Ram , Kapoor Ramesh N
Published: July 2006

Bis(cyclopentadienyl)zirconium(IV) Schiff base derivatives have been synthesized by treating dichlorobis(cyclopentadienyl)zirconium(IV) (Cp2ZrCl2) with bidentate Schiff bases (SBH) viz.,  N-salicylidenaniline, N-salicylidene-o-toluidine, N-salicylidene-m-toluidine, N-salicylidene-p-toluidine, and N-(2-hydroxyl-1-naphthyliden)aniline, terdentate Schiff bases (SB′H2) viz.,  N-(3-oxo-1-methylbutyliden)-o-aminophenol and N-(3-oxo-1-phenylbutyliden)-o-aminophenol; quadridentate Schiff base (SB″H2) N,N′-disalicylidene-o-phenylenediamine, in THF, in the presence of triethylamine at room temperature. The resulting derivatives of the type Cp2Zr(SB)Cl, Cp2Zr(SB)2, Cp2Zr(SB′), Cp2Zr(SB″), and (Cp2ZrCl)SB″ [where [SB]−, [SB′]2−, and [SB″]2−-represent the anion of corresponding Schiff bases SBH, SB′H2, and SB″H2] have been characterised by their elemental analysis and by IR, electronic spectra, electrical conductance and molecular weight determinations.
Synthesis and Absorption Spectra of Some 6-Hydroxythiazolo[3,2-a]-benzimidazoles and Their Quaternary Derivatives
Authors: Soni R P , Saxena J P
Published: July 2006

A series of substituted 6-Hydroxythiazolo[3,2-a]benzimidazoles has been synthesized. Their quaternary derivatives showed characteristic absorption maxima at longer wavelengths in visible region. The spectral study of parent compounds in the visible region shows a red shift at higher pH which is attributed to the dipolar nature of these compounds.
Magnetic Studies on Basic Salts of Copper, Dicopper Arsenate Hydroxide, Dicopper Hydroxide Phosphate, and Dicopper Oxide Sulfate
Authors: Asai Takeshi , Saheki Hiroshi , Kiriyama Ryôiti
Published: July 2006

Magnetic susceptibilities, χ, of Cu2AsO4(OH), Cu2(OH)PO4, and Cu2OSO4 have been measured from 4.2 to 360 K to establish the role of the OH− and O2− ions in the magnetic superexchange interaction. The former two compounds showed a broad maximum for χ at 118 and 110 K, respectively. Although the crystal structure is three-dimensional, only a tetramer model with two parameters can explain the temperature dependence of χ, since the hydroxide anion causes a strong magnetic interaction which is limited to four copper atoms between which the anion is intermediary. The magnetic susceptibility of Cu2OSO4 obeyed the Curie-Weiss law above 140 K with a Weiss constant of −56 K. At 16 K the compound transformed into a ferrimagnetic phase, the effective megneton number of which is 0.11 at 4.2 K. A canted ferrimagnetic structure has been proposed and the canting angle estimated. In the superexchange interaction, only hydroxide and oxide anions are significant and both anions behave similarly.
The Polarographic Reduction and UV Spectral Properties of Pentaamminecarboxylatoruthenium(III) Complexes
Authors: Ohyoshi Akira , Yoshikuni Kenichiro
Published: July 2006

Pentaamminecarboxylatoruthenium(III) complexes are reversibly reduced to the corresponding Ru(II) complexes by means of a one-electron transfer at the dropping mercury electrode in aqueous solutions. The absorption maxima, which ranged from 34.6×103 cm−1 (trichloroacetato complex) to 33.6×103 cm−1 (glycinato complex) were assigned to the charge-transfer from ligand to metal; they were linearly related to the reversible half-wave potential.
Metal-substitution of 12-Heteropolymolybdate with Iron Atoms
Authors: Nomiya Kenji , Sugaya Motoki , Miwa Makoto
Published: July 2006

Triheteropolymolybdates of [XFeMo11O40H2]-and [XFeMo11O40H3]-type have been synthesised by the metalsubstitution reaction of 12-heteropolymolybdate of [XMo12O40]-type (X is Si or P) and their properties have been investigated.
Studies of Tritylated Pentoses and 6-Deoxyhexoses. II. Trityl Ethers of Methyl a- and β-l-Rhamnopyranoside and Their Derivatives
Authors: Otake Toshiki , Sonobe Toru , Suami Tetsuo
Published: July 2006

Mono-O-trityl derivatives of methyl α- and β-l-rhamnopyranoside have been prepared and the structures established by PMR analysis.
New Synthesis of Alkyl Polysulfides by Treatment of Thiols, Disulfides and Thionitrites with Anhydrous Copper(II) Chloride
Authors: Kim Yong Hae , Shinhama K\={o}ichi , Oae Shigeru
Published: July 2006

Reaction of several divalent organic sulfur compounds with copper(II) chloride in acetonitrile gave the corresponding disulfides or other polysulfides in good yields under mild conditions.
Reactive Troponoids and o-Aminophenol. IV. The Synthesis of 8-Arylazocyclohepta[b][1,4]benzoxazine by the Reaction of Arylazotropolone with o-Aminophenol
Authors: Someya Taichi
Published: July 2006

8-Phenylazocyclohepta[b][1,4]benzoxazine was obtained by the dehydration of 5a-hydroxy-8-phenylhydrazonocyclohepta[b][1,4]benzoxazine, which had itself been obtained by the reaction of 5-phenylazotropolone with o-aminophenol.
Selective Spectrophotometric Determination of Zinc with Di-2-pyridylmethanone 2-Pyrimidylhydrazone
Authors: Singh R B , Kulshreshtha H , Garg B S , Singh R P
Published: July 2006

Synthesis of a new 2-pyrimidylhydrazone i.e. di-2-pyridylmethanone 2-pyrimidylhydrazone (DPMPH) and its application in the selective determination of microamounts of zinc is presented. DPMPH reacts with zinc to form a yellow complex in the pH range 7.9–11.1 with molar absorptivity 5.2×104 l mol−1 cm−1 at 430 nm. Beer’s law is obeyed up to 1.56 ppm of zinc. Zinc has also been determined in several alloys.
On Thallium(I) Chelates of 1,2-Cyclohexanediamine-N,N,N′,N′-tetraacetic Acid and Diethylenetriaminepentaacetic Acid
Authors: Anderegg Giorgio , Bottari Emilio
Published: July 2006

The stability constants of the complexes mentioned in the title obtained by us by potentiometric pH measurements are compared with those of Kodama et al. Because sodium ion forms quite a stable 1,2-cyclohexanediamine-N,N,N′,N′-tetraacetate (CyDTA) complex, the discrepancy of the values can be explained. Further new calculations confirm the formation of protonated chelate with CyDTA but in a very limited pH range.
The Crystal Structures of Methylammonium Hexachlorostannate(IV) in the High- and Low-temperature Phases Studied by X-Rays
Authors: Kitahama Katsuki , Kiriyama Hideko , Baba Yoshihisa
Published: July 2006

The title compound crystallizes in the trigonal space group R\bar3m with a=7.171, c=21.952 Å, and Z=3 at 298 K. The crystal structures at 298 and 120 K, as well as the lattice parameters in the temperature range 113–298 K, have been determined by X-rays, in order to elucidate the mechanism of the phase transition occurring at Tt=156 K. The structure of the high-temperature phase is essentially the same as that determined by Wyckoff, except for the discrimination between C and N atoms. No change in the space group nor in the basic structure was detected over the temperature range studied, in spite of a strong suggestion from previous 35Cl-NQR measurements. A small but significant anomaly associated with the transition is recognized in the c axis, which retains almost the same length near and below Tt. As a result, the lattice shrinkage below Tt becomes increasingly anisotropic as the temperature is lowered, whereas the thermal expansion above it is relatively isotropic.
Temperature Dependence of Reorientational and Vibrational Relaxation Times of Benzene and Benzene-d6 in Solid and Liquid Phases
Authors: Nomura Hiroyasu , Koda Shinobu , Miyahara Yutaka
Published: July 2006

The temperature dependences of reorientational and vibrational relaxation times of benzene and benzene-d6 in the solid and liquid phases were measured by means of Raman line shape analysis. The temperature dependence of the reorientational relaxation times was in very good agreement with that published previously. The vibrational relaxation times of benzene changed drastically at the solid to liquid phase transition point both in C6H6 and C6D6. We consider that this effect is due to the non-radiative energy transfer and the pure dephasing process by molecular collisions in the liquid state.
A Kinetic Study of the Reaction of Arylthiotrimethylsilane with Carboxylic Acid Giving Acyloxytrimethylsilane and Arenethiol
Authors: Kozuka Seizi , Kitamura Takuro
Published: July 2006

The mechanism of the reactions of arylthiotrimethylsilanes with carboxylic acids has been studied kinetically. The reaction was found to obey a second-order kinetic equation. The substituent effects of the aryl moiety (ρ=−2.4) and of the silicon atom, the hydrogen-deuterium kinetic isotope effect of the acid (kH/kD=3) were observed. A mechanism involving the 5-coordination of the silicon atom prior to the rate-determining protona-tion of the sulfur atom has been suggested for the reaction. A remarkable base catalysis was observed. The formation of the coordinated intermediate has been suggested to be the slow step in the presence of a bese.
Oxygen-17 Nuclear Magnetic Resonance. III. Oxygen Atoms with a Coordination Number of Two
Authors: Sugawara Tadashi , Kawada Yuzo , Katoh Morimatsu , Iwamura Hiizu
Published: July 2006

Fourier transform 17O NMR spectra have been measured for a number of alcohols, ethers, acetals, formates, acetates, and esters of inorganic acids in natural abundance at 10.8 MHz. The 17O chemical shifts which cover a range as large as several hundred ppm are primarily governed by the sum of electronegativity of the first atoms or groups attached to the central oxygen. The downfield shift due to β-methyl groups in alcohols and ethers is in parallel with decrease in their ionization potentials, demonstrating the importance of the paramagnetic screening term in the 17O shifts of these compounds. Diamagnetic shift due to γ-carbons and -oxygens has also been disclosed.
Studies on Xanthylium Salts. Behaviour of 9-Vinylidenexanthenes in Acid Media
Authors: Abdul-Malik Nadia Fouad , Awad Sami Bassili , Sakla Alfy Badie
Published: July 2006

Unsymmetrical allenes namely, 1,1-diaryl-2-(9′-xanthenylidene)ethylenes (1) reacted readily with perchloric acid, hydrogen chloride, and acetic acid to give the corresponding highly coloured 9-vinylxanthylium salts (3). The latter derivatives (3) thermally rearranged in acid media to give spiro[indene-1,9′-xanthene]s (7). Structures of compounds 3 and 7 were established from chemical and spectral evidences. A new route for synthesis of allenes (1) was reported.
Calculation of the H4 Potental Energy Surface by a Semi-empirical Method
Authors: Tanaka Noboru
Published: July 2006

A semi-empirical method recently proposed for the calculation of the potential energy surface of the H3 system is extended to a larger polyatomic H4 system. The energy formula is based on the valence-bond formulation and is expressed as functions of many multiple exchange integrals. These integrals can be decomposed into “diatomic” contributions by using the Mulliken approximation. The diatomic contributions are estimated from accurate values of the H2 molecule. Calculations of the H4 potential energy for the symmetric linear, linear equidistant, and square planar configurations are presented. The present method is of use for dynamical studies of the H2+D2 exchange reaction.
The Activities of Methyl Orange and Homologs in Aqueous Solutions
Authors: Mitsuishi Masaru , Yamaguchi Yuzoh
Published: July 2006

The mean activity coefficients of Methyl Orange (MO), Ethyl Orange (EO), Propyl Orange (PO), and Butyl Orange (BO) in aqueous solutions ranging in concentration from 10−3 to 10−2 mol kg−1 have been determined by means of isopiestic measurements at 50 and 60 °C respectively. It has been found that the mean activity coefficients of MO being the largest, and those of BO, the smallest. The coefficients have been found to decrease with an increase in the dye concentration. The examination of the results by Milicéivic treatment suggests that MO, EO, and PO are present as a monomer or a dimer, while BO exists as a trimer at 60 °C.
Molecular Force Field of Dialkyl Selenides
Authors: Matsuura Hiroatsu , Murata Hiromu
Published: July 2006

The molecular force field in terms of the local symmetry coordinates was determined for unbranched dialkyl selenides. Twenty-six important force constants associated with the selenium part were adjusted by using about two hundred observed vibrational wave numbers for a total of twelve conformational isomers of ethyl methyl selenide, diethyl selenide, methyl propyl selenide, butyl methyl selenide, and ethyl propyl selenide. Remaining force constants of the selenides were assumed to be equivalent to those for unbranched dialkyl sulfides and alkanes. The least-squares calculation gave an overall root-mean-square deviation of 6.7 cm−1 between the observed and calculated wave numbers. The force constants and the results of the normal coordinate treatment are given in this paper.
Trimethylenediamine Complexes. VIII. Some Cis-Trans Isomeric Pairs of the Bis(trimethylenediamine)chromium(III) Complexes
Authors: Nakano Mamoru , Kawaguchi Shinichi
Published: July 2006

The cis-trans isomeric pairs of diisothiocyanato-, dinitrito-, diazido-, diaqua-, and aquahydroxo-bis(trimethylenediamine)chromium(III) complexes have been obtained as crystals and characterized by infrared and electronic absorption spectra. The cis isomers of diisothiocyanato and diazido complexes as well as [Cr(N3)2(en)2]ClO4 were resolved and the absolute configurations of (+)589-cis-[Cr(NCS)2(tn)2]SCN, (+)589-cis-[Cr(N3)2(tn)2]ClO4, and (−)589-cis-[Cr(N3)2(en)2]ClO4 were all assigned to Δ.
The Acid Catalyzed Decomposition of Diazo Compounds. I. Synthesis of Oxazoles in the BF3 Catalyzed Reaction of Diazo Carbonyl Compounds with Nitriles
Authors: Ibata Toshikazu , Sato Ryohei
Published: July 2006

The BF3-catalyzed decomposition of diazo carbonyl compounds in nitriles have afforded the corresponding oxazoles in high yields. This method is applicable to diazo carbonyl compounds such as m- and p-substituted diazoacetophenones, ethyl diazoacetate, 1,2-diphenyl-2-diazoethanone, dibenzoyldiazomethane, and dimethyl diazomalonate. Bis(diazo ketone)s such as terminal bis(diazoacetylated) alkanes (III1−4: n=6, 8, 10, 12) and m-and p-bis(diazoacetyl)benzenes also gave the corresponding bisoxazoles in a similar reaction. The reaction has been interpreted in terms of a stepwise mechanism via betaine intermediates initiated by the attack of BF3 on the carbonyl oxygen of diazo carbonyl compounds. The emission spectra of oxazoles are described.
Diversity in the Base-induced Photoreactions of Thiolane-2,4-dione and Derivatives. Reductive Ring Cleavage and Novel Rearrangements of the Carbon Skeleton
Authors: Saito Kimitoshi , Sato Tadashi
Published: July 2006

The irradiation of thiolane-2,4-dione (thiotetronic acid) and its derivatives, 1a–1d, in methanol in the presence of bases induced the reductive ring cleavage to give β,β′-diketo esters. The base-induced reductive ring cleavage was also observed in aprotic solvents, such as acetonitrile or acetone, although the products were obtained as β,β′-diketo amides in these cases. On the other hand, the irradiation of 1a–1d in water in the presence of bases induced a rearrangement of the carbon skeleton to give succinic thioanhydrides, γ-keto amides or succinamides, along with the reduction products. When pyridine was used as a base in the photolysis in water, two 3-acetyl derivatives, 1a and 1b, gave γ-keto thiols and the corresponding disulfides, resulted from another type of rearrangement of the carbon skeleton. Conceivable reaction mechanisms were discussed.
New Methods for Synthesis of α,β-Unsaturated Carboxylic Esters from Carbonyl Compounds Using Monoanions of Dithiocarbonates, and Dianions of Ethyl Mercaptoacetate and Ethyl 2-Mercaptopropionate
Authors: Tanaka Kazuhiko , Yamagishi Nobuyuki , Tanikaga Rikuhei , Kaji Aritsune
Published: July 2006

The lithium enolates of O-alkyl S-alkoxycarbonylmethyl dithiocarbonates and monothiocarbonates were found to be efficient reagents for the synthesis of α,β-unsaturated esters from carbonyl compounds by single-step procedure. The dianions of ethyl mercaptoacetate and ethyl 2-mercaptopropionate were successfully generated by treatment with 2.2 equivalents of lithium diisopropylamide (LDA) in the presence of N,N,N′,N′-tetramethylethylenediamine (TMEDA) at −78 °C in THF. The dianions so formed are highly reactive toward various electrophiles. The procedure leads to a novel one-pot synthesis of α,β-unsaturated carboxylic esters from carbonyl compounds.
Elimination Reactions of Halohydrin Derivatives with a Palladium (0) Complex
Authors: Sugita Toshio , Shiraiwa Yoshimi , Hasegawa Masayuki , Ichikawa Katsuhiko
Published: July 2006

Stilbene bromohydrin derivatives (Ph–CHBr–CHY–Ph: Y=OAc, OSO2CH3, OCH3, SCH3) and stilbene dibromide underwent β-elimination reaction with tetrakis(triphenylphosphine)palladium(0) to give stilbene. The stereochemistry of eliminations is nonselective except in the case of dibromide, where anti-selectivity is observed. A coupling reaction occurred favorably in the case of Y=OCH3.
The Jacobsen Rearrangement of Tribromobenzenes
Authors: Nakada Masahiro , Ishibashi Kiichiro , Fukushi Sachio , Hirota Minoru
Published: July 2006

The Jacobsen rearrangement of tribromobenzenes was investigated at 110–180 °C in concentrated sulfuric acid. The reaction proceeds exclusively via the intramolecular 1,2-migration of the bromine atom, which is accelerated by the steric repulsion of the neighboring group. Sulfonation of both the reactant and the products occurs simultaneously with the rearrangement. The migration of bromine atoms in the sulfonic acids proceeds far more slowly, the rearranged products not being formed to any considerable extent by sulfonic acids.
Chemical Reactivity of Würster’s Salts at Very High Pressure
Authors: Onodera Akifumi , Sakata Tadayoshi , Tsubomura Hiroshi , Kawai Naoto
Published: July 2006

The electrical and chemical properties of some Würster’s salts have been studied under the static pressure of up to 250 kbar. In most cases the resistances of the salts decreased to the respective minima and then rose irreversively with increasing pressure. Spectral observations on the recovered specimens revealed that such behavior is associated with chemical reaction induced by the pressure. This reaction takes place more readily in the salts of p-phenylenediamine cation radical than in those of Würster’s red or Würster’s blue radicals.
Magnetic Susceptibility and Low-field ESR of an Organic Ion-radical Salt, Tri-p-tolylaminiumyl Chloroantimonate
Authors: Yoshioka Toshio
Published: July 2006

The static magnetic susceptibility and the low-field ESR spectra (33.6 and 135 MHz) of powder samples of tri-p-tolylaminiumyl chloroantimonate were measured above 1.7 K. A broad maximum in the susceptibility, which indicates an antiferromagnetic interaction, was observed at 6.0 K; this is consistent with the results of the proton NMR measurements. In the low-field ESR spectra, broadening of the g=2 absorption line and distinct appearance of the g=4 absorption line were observed in the temperature region below Tm, the temperature at which the susceptibility is maximum. The results are interpreted by assuming that the magnetic behavior is due to antiferromagnetic Heisenberg linear chains. An abrupt decrease in the g=2 absorption intensity and a rapid increase in the g=2 absorption linewidth were also found in the temperature range from 3.5 to 2.5 K, while a slight rise in the susceptibility was observed below 2.5 K. These anomalies may imply a magnetic-phase transition in the vicinity of 2.5 K.
The Crystal and Molecular Structure of Dichloro[1,3-bis(di-t-butylphosphino)propane]platinum(II) Chlorobenzene Solvate
Authors: Harada Masahiro , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami
Published: July 2006

X-Ray crystal structure analysis of [PtCl2{(t-Bu)2P(CH2)3P(t-Bu)2}]·0.5C6H5Cl has been carried out. Crystals belong to monoclinic system: a=11.532(2), b=14.984(5), c=16.455(4) Å, β=106.96(2)°, space group P21/c with Z=4. The structure, solved by the heavy-atom method, has been refined anisotropically by least-squares procedure to R=0.056 for 5019 non-zero reflections. The coordination around the platinum atom is approximately square-planar, however, it showed a slight deviation toward the tetrahedral geometry; Pt–P=2.281(3) and 2.282(3), Pt–Cl=2.359(3) and 2.362(3) Å, P–Pt–P=99.05(9) and Cl–Pt–Cl=83.18(11)°.
The Crystal Structure of fac(N)-Δ-Tris(l-asparaginato)cobalt(III) Trihydrate
Authors: Sekizaki Masao
Published: July 2006

The crystal structure of tris(l-asparaginato)cobalt(III) trihydrate, [Co(l-H2NCOCH2CHNH2COO)3]·3H2O, has been determined by the X-ray diffraction method, and refined by a block-diagonal least-squares method to give R=0.055 for 1302 non-zero reflections. The crystals are orthorhombic with a space group P212121, a=39.082(4), b=7.523(2), c=6.643(2) Å, and Z=4. The complex molecule has a slightly distorted octahedral coordination with fac(N)-Δ geometry. The three bidentate ligand ions form five-membered planar chelate rings with coordination through amino nitrogen and carboxyl oxygen atoms. The amide groups of the two side-chains approach the central atom, and the oxygen atoms are connected through intramolecular hydrogen bonds. Another amide group is, however, far from the central atom. The complex molecules are hydrogen-bonded to one another to form layers parallel to the (100) plane. These layers are piled up through hydrogen bonds to complete a threedimensional network.
Stereochemistry of Cobalt(III) Complexes with Sulfur-containing Amino-carboxylate. Mixed Cobalt(III) Complexes with l-Methioninate or S-Methyl-l-cysteinate and l- or d-Aspartate
Authors: Isago Takashi , Igi Kozo , Hidaka Jinsai
Published: July 2006

Four kinds of [Co(N)2(O)3(S)] type mixed complexes, (l- or d-aspartato)(l-methioninato), and (l- or d-aspartato) (S-methyl-l-cysteinato)cobalt(III) complexes have been prepared and chromatographically separated into their three geometrical isomers, trans(N), trans(SO) and trans(SN), respectively. The isomers were identified from their electronic absorption and PMR spectra. The absolute configurations of sulfur atoms in the ligands after coordination were suggested on the basis of their PMR spectra. The circular dichroism spectra of the isomers were considered in relation to their geometrical configurations.
X-Ray Diffraction Studies on the Structures of Tetra- and Higherammine Complexes of Copper(II) Ion in Aqueous Solution
Authors: Yamaguchi Toshio , Ohtaki Hitoshi
Published: July 2006

From X-ray scattering measurements on ammoniacal aqueous solutions of copper(II) chloride at the NH3/Cu mole ratios of 4.8 and 5.0, four ammonia molecules at the equatorial position and other two water molecules at the axial one were found to be coordinated to a copper(II) ion at the distance of 2.03 and 2.33 Å, respectively. The radial distribution curve obtained for an aqueous solution of copper(II) chloride saturated with ammonia (NH3/Cu=11.2) showed that a higher ammine copper(II) complex than the tetraamminecopper(II) ion is formed in the solution. The complex has a distorted octahedral form in which the equatorial Cu–N bond distance is 1.93 Å. The axial apices of the octahedron at the distance of 2.30 Å are occupied by either an ammonia molecule and a water molecule or two ammonia molecules. The present study shows that the structures of the tetra- and higher-ammine copper(II) complexes in solution are different from those in crystal.
Preparation and Optical Resolution of [Co(en)x(dmbpy)3−x]3+ (x=0,1) and Related Complexes
Authors: Suzuki Toshishige M
Published: July 2006

The optical resolution of [Co(dmpy)3]3+, [Co(en)(dmbpy)2]3+, [Co(en)(bpy)2]3+, and [Rh (dmbpy)3]3+(dmbpy=3,3′-dimethyl-2,2′-bipyridine) has been achieved using (−)d tris(l-cysteinsulfinato)cobaltate(III). The dmbpy complexes consist of a pair of stereo-selective enantiomers. The absorption and CD spectra of two series of complexes, [Co(en)x(dmbpy)3−x]3+ and [Co(en)x(bpy)3−x]3+ (x=0, 1, 2, 3) and also [Rh(dmbpy)3]3+ have been investigated. The complexes containing more than two aromatic ligands showed an exciton CD in the ligand π-π* transition region and the band has been related to the absolute configuration of the complexes. The spectral features of dmbpy Complexes are different from those of the bpy complexes and such differences have been discussed with reference to the twisting nature of dmbpy chelates.
Phase Equilibria in the Er2O3–V2O3–V2O5 System at 1200 °C
Authors: Kitayama Kenzo , Sugihara Tadashi , Katsura Takashi
Published: July 2006

The phase equilibria in the Er2O3–V2O3–V2O5 system have been established at 1200 °C. In this system, Er2O3, Er8V2O17(4Er2O3·V2O5), ErVO3, ErVO4, VnO2n−1(n: 2 to 7), and VO2 found to be stable, Er8V2O17, ErVO4, V2O3, and VO2 of which had non-stoichiometric compositions. On the basis of the phase equilibria, the standard Gibbs energies for the reactions,

ErVO3+1⁄2O2=ErVO4, (1)

3Er2O3+2ErVO3+O2=Er8V2O17, (2)

have been determined to be −121±1 and −256±1 kJ, respectively. It has been shown that the standard Gibbs energy for Sm, Er, and Lu in Eq. 1 decreases linearly with increasing ionic radius of lanthanoid.
Reaction of Bis[2-hydroxy-1-(2,6-dimethyl-4-methoxyphenyl)ethyl] Ethers with Tosyl Chloride
Authors: Nakatani Munehiro , Hase Tsunao
Published: July 2006

In the reaction with tosyl chloride in pyridine, the meso isomer (2a) of bis[2-hydroxy-1-(2,6-dimethyl-4-methoxyphenyl)ethyl] ether rearranged to give arylacetaldehyde (3) and 2-arylmethyl-4-aryl-1,3-dioxolane (4), and the racemic isomer (2b) afforded 3, 4, and 2,6-diaryl-1,4-dioxane. The aryl migration in this reaction has been confirmed by the use of the deuterated compounds, 2a-D and 2b-D, respectively, substituted with deuteriums at the 2,2-positions.
Thermal and Acid-catalyzed Decomposition of 3,6-Diphenyl-1,4-bis(phenylsulfonyl)-1,4-dihydro-1,2,4,5-tetrazine
Authors: Ito Suketaka , Kakehi Akikazu , Tanaka Yumo , Yoshida Kazuyoshi , Matsuno Toshiyuki
Published: July 2006

Thermolysis of the title dihydrotetrazine in boiling toluene gives benzenesulfonic anhydride, S-phenyl benzenethiosulfonate, and small amounts of diphenyl disulfide and a rearrangement product, 3,6-diphenyl-1,2-bis(phenylsulfonyl)-1,2-dihydro-1,2,4,5-tetrazine, together with 3,6-diphenyl-1,2,4,5-tetrazine. On the other hand, the treatment with concentrated sulfuric acid affords 3,6-diphenyl-1,4-dihydro-1,2,4,5-tetrazine in good yield. On the basis of the kinetic parameters obtained for the thermolysis, the mechanism was discussed.
Radiation-induced Reactions of Pyridinecarboxylic Esters in Acidic Alcoholic Solutions. Substitution by Alkyl and Hydroxyalkyl Groups and Reduction of Carboxylic Esters to Alcohol
Authors: Nakamura Kazuhito , Morita Yukari , Suzuki Toru , Sugiyama Toru , Sugimori Akira
Published: July 2006

The main reactions of pyridinecarboxylic esters induced by Co-60 γ-rays in acidic alcoholic solutions are: 1) substitution on the pyridine ring by alkyl or hydroxyalkyl groups derived from solvent alcohols, and 2) reduction of carboxylic esters to alcohol (hydroxymethyl group). Substitution is dominant in methanol solutions and reduction is dominant in 2-propanol solutions. Carboxylic esters at the 2- and 4-positions are selectively reduced to alcohols. Alkylation results from the attack by hydrogen atoms and hydroxylalkyl radicals. Reduction of carboxylic esters to alcohol is effected by the hydroxyalkyl radicals derived from the radiolysis of alcohols.
Substituent Effects in Heterogeneous Catalysis. IV. Adsorption Estimations during Competitive Hydrogenation of Cyclohexanone and Its 2-Alkyl Derivatives
Authors: Chihara Teiji , Tanaka Kazunori
Published: July 2006

Cyclohexanone (1) and its 2-alkyl derivatives (2-methyl-, 2-ethyl-, and 2-propylcyclohexanone (2m, 2e, and 2p)) were hydrogenated both individually and competitively in pairs (1+2) in cyclohexane using Ru/Al2O3, Rh/Al2O3, and Pt/Al2O3 as catalysts. For all the catalysts, the reaction rates in competitive reaction decreased in the sequence, l>>2m>2e>2p, while those in individual reaction were in the relation, 1>2m≈2e≈2p. By the analysis of these kinetic data, the relative values of adsorption equilibrium constants have been estimated for 2m, 2e, and 2p. These experimental values are in good agreement with the theoretical ones which have been derived on the basis of statistical mechanics using an adsorption model characterized by immobile adsorption of the substrate ketones.
Reduction of 6,6-Disubstituted Fulvenes and 1,2-Benzoheptafulvene by Naphthalene Radical Anion
Authors: Oku Akira , Yoshida Mitsuhiro , Matsumoto Kenkichi
Published: July 2006

Structural effects of fulvenes in the electron transfer reaction were examined by using naphthalene radical anion (1) as a homogeneous electron source in aprotic media. The reduction of 6,6-diphenylfulvene (2) with 1 in THF at−78 °C gave 3-benzhydrylcyclopentadiene (34%) and its 2-isomer (13%). The structures were determined by hydrogenation and by the reaction with N-phenylmaleimide. The reaction of 6,6-dimethylfulvene (3) with 1 gave bi(2-isopropylidene-3-cyclopentenyl) as the major product (39%) besides bi(2-isopropyl-1,3-cyclopentadienyl) (5%). The reaction of 3,3′,4′,5,5′,6,6′-heptamethyl-1,2-benzoheptafulvene (4) with 1 gave 3,3′,4′,5,5′,-6′,7-octamethyl-1,2-benzo-1,3,6-cycloheptatriene (32%) and 3,3′,4′,5,5′,6,6′,7-octamethyl-1,2-benzo-1,3,5-cycloheptatriene (18%). These product structures as well as the CH3I- and D2O-quenching of the reduction intermediates indicate that 2 is reduced by the EEC-mechanism and 3 by the ECC-mechanism, whereas the results are rather complicated in the case of 4 to distinguish between EEC and ECC mechanism.
Synthesis of Viscumamide and Its Analogs
Authors: Sakurai Atsushi , Okumura Yasuaki
Published: July 2006

Viscumamide, cyclo(–l-Leu–l-Ile–l-Leu–l-Ile–l-Leu–) (1a) and its three analogs, cyclo (–l-Leu–l-Leu–l-Leu–l-Leu–l-Leu–), cyclo (–l-Leu-l-Ile-l-Leu–l-Leu–l-Leu–), and cyclo (–l-Ile–l-Ile–l-549.tex Leu–l-Leu–l-Leu–) were synthesized by the N-hydroxysuccinimide ester method. The yields in the cyclization step were low due to a strong intermolecular association even at high dilution, which causes cyclodimerization and other polymerization. Chromatographic and spectroscopic comparison of synthetic 1a with natural viscumamide showed their identity. The structure of viscumamide was confirmed to be 1a.
High Pressure Organic Chemistry. III. Diels-Alder Reaction of Thiophene with Maleic Anhydride
Authors: Kotsuki Hiyoshizo , Nishizawa Hitoshi , Kitagawa Sachio , Ochi Masamitsu , Yamasaki Nakamichi , Matsuoka Kiyoshi , Tokoroyama Takashi
Published: July 2006

The Diels-Alder reaction of thiophene with maleic anhydride has been investigated under conditions of very high pressure. The Diels-Alder adduct was obtained in dicbloromethane at 100 °C and 15 kbar; above a pressure of 15 kbar the reaction was highly accelerated. From the spectral data and chemical evidence it has been suggested that the adduct has the exo-configuration. The reactions in various solvents and with other dienophiles have also been examined.
Reduction of Some Sulfides and Ethers with Aromatic Rings by Electrochemically Generated Solvated Electrons
Authors: Miyake Mikio , Nakayama Yoshihiro , Nomura Masakatsu , Kikkawa Sh\={o}ichi
Published: July 2006

The reduction of some sulfides and ethers has been investigated in 0.5 M LiCl–HMPA solutions with and without alcohol (methanol, ethanol, and 2-propanol). Diphenyl sulfide underwent cleavage to produce benzene as the main product. The hydrogenated products of benzene have been obtained in 35 and 50 mol % alcohol solutions, and the increased dependence on ethanol (i.e., H+) concentrations in the solutions has been established. The cleavage reaction was affected by the ease of α-hydrogen abstraction from the alcohol. The cleavage reaction has been elucidated as proceeding via a one-electron transfer mechanism, while the hydrogenation proceeded via a two-electron transfer mechanism. The estimation of current efficiencies supports this mechanism. Hexyl phenyl sulfide cleaved in the manner similar to that for diphenyl sulfide with a current efficiency of about 80% whereas only the hydrogenated products were obtained from benzo[b]thiophene and dibenzothiophene. Fission of the C–S bond of tetrahydrothiophene has been achieved by this method. Some ethers examined exhibited approx. the same behavior as the corresponding sulfides.
Thermodynamics of Steady States: “Resistance Change” Transitions in Steady-state Systems
Authors: Tykodi R J
Published: July 2006

Some one-current steady-state systems showing a discontinuous change in flow resistance at a point of instability—forced vaporization of carbon tetrachloride, Bénard instability in a horizontal layer of fluid heated from below, Taylor instability in the Couette flow of a liquid between coaxial rotating cylinders—are analyzed from a thermodynamic point of view: the behavior of the rate of entropy production and of the local potential (thermokinetic potential) for the system at the point of instability is explored. A multi-current situation involving a flip-flop current vs. voltage relation for the flow of electric current across a porous charged membrane is also commented on briefly.
Studies of the Metal Complexes of Cyclohexane Derivatives. V. Copper(II) and Nickel(II) Complexes of cis-1,3-Cyclohexanediamine
Authors: Saito Reiko , Kidani Yoshinori
Published: July 2006

A series of 1,3-chxn(cis-1,3-cyclohexanediamine) copper(II) and nickel(II) complexes have been prepared and studied using spectroscopic and magnetic techniques. The violet and red copper(II) complexes of 1,3-chxn were found to consist of monomeric distorted octahedra and slightly distorted square planers, respectively. The nickel(II) complexes have a square planar structure. The conformational change of the ligand from diequatorial to diaxial on coordination has been confirmed by infrared analysis.
Temperature and Composition Dependences of Transport Processes in Glass-forming Molten Mixtures of Zn(NO3)2·6.27H2O and CoCl2
Authors: Islam Nurul , Singh Kunwar Pal , Kumar Satendra
Published: July 2006

Density, viscosity, and electrical conductivity of glass-forming mixtures of zinc nitrate hexahydrate and anhydrous cobalt chloride were measured as functions of temperature and concentration. Non-Arrhenius temperature dependence of equivalent conductance, Λ and fluidity, φ has been discussed in terms of a three parameter equation derived from Adam-Gibbs model. A linear correlation has been obtained between the preexponential parameter, AY and the ideal glass transition temperature, T0. The composition dependence of Λ and φ has been described by the expression derived from the Adam-Gibbs equation on the criteria of constant T/T0, where T is the absolute temperature, and a modification to this expression has been made. An attempt has been made to describe the concentration dependence of Λη product in terms of modified Adam-Gibbs equation.
Solvent Extraction and Spectrophotometric Determination of Palladium with 3-(2-Hydroxy-5-methylphenyl)-5-(p-methoxyphenyl)isoxazoline
Authors: Deshmukh B K , Kharat R B
Published: July 2006

3-(2-Hydroxy-5-methylphenyl)-5-(p-methoxyphenyl)isoxazoline (HMPAO) is used for the simultaneous extraction and direct photometric determination of palladium. About 46 μg of palladium was quantitatively extracted at pH 1.0—2.0 with 10 ml of 1.0×10−3M HMPAO in isobutyl alcohol as a yellowish complex. It was measured spectrophotometrically at 332 nm, The system conformed to Beer’s law over the concentration range 1.0—20.0 μg of palladium per ml. The colour of the complex was stable for more than 48 h. Palladium was extracted quantitatively and was determined in the presence of large excess of ions which are associated with it. The extractable species was 1:2 (Pd: HMPAO) in nature. The equilibrium constants were determined according to the methods of Yatsimirskii and Leden with suitable modification.
Extraction-Spectrophotometric Determination of Vanadium(V) Employing N1-Hydroxy-N1,N2-diarylbenzamidines and Various Adduct-forming Substances
Authors: Patel K S , Mishra R K
Published: July 2006

The reactions of 16 newly synthesized N1-hydroxy-N1,N2-diarylbenzamidines with vanadium(V) in presence of various adduct-forming substances have been investigated photometrically in chloroform. The present study indicated the formation of 1:2:1 metal:reagent:acetic acid or phenol and 1:2:2 metal:reagent:thiocyanate complexes. On the basis of strong synergism, which is attributed to mixed-complex formation, simple, rapid, sensitive and selective methods for the spectrophotometric determination of microgram quantities of vanadium(V) have been developed. The influence of experimental variables on the procedures have been discussed.
Quaternisation at an Sp2 Nitrogen. II. An Analysis on the Substituent Effect and on the Nature of the Transition State
Authors: Behera G B , Sharma A
Published: July 2006

The kinetics of N-phenacylation of a number of substituted thiazoles and substituted phenacyl bromides have been investigated in nitrobenzene and in a number of other dipolar aprotic solvents. The rate constants of 2-amino-4-phenylthiazoles and 2-aminobenzothiazoles have been calculated with suitably developed equations. The deviation of the observed values from the calculated results has been ascribed to the steric effect. A seven membered hydrogen bonded transition state has been proposed on the basis of the results obtained from the substituent and medium effect.
Synthetic Studies on Terpenoids. I. Stereocontrolled Synthesis of (±)-1,2,3,4,4a,9,10,10a-Octahydro-7-methoxy-1,4a-dimethyl-10-oxophenanthrene-1β-carboxylic Acid: A Potential Intermediate for Diterpenoid Synthesis
Authors: Banerjee Ajoy K , Ceballo Carmen D , Vallejo Maria N , Bolivar Edith H
Published: July 2006

A stereocontrolled synthetic route to (±)-1,2,3,4,4a,9,10,10a-octahydro-7-methoxy-1,4a-dimethyl-10-oxophenanthrene-1β-carboxylic acid and its conversion to 1,2,3,4,4a,4b,5,6,7,9,10,10a-dodecahydro-10β-hydroxy-1,4a-dimethyl-7-oxophenanthrene-1β-carboxylic acid is described.
Oxidation of 2,6-Dialkyl-p-cresols by Metal Acetates
Authors: Itahara Toshio , Sakakibara Tsutomu
Published: July 2006

The oxidation of 2,6-dialkyl-p-cresols by silver(I) and palladium(II) acetate afforded the corresponding p-hydroxybenzyl acetates and p-hydroxybenzaldehydes.
Synthesis and Magnetic Behavior of Three Novel Di-μ-halobis[halo(1,2-benzoquinonedioxime)copper(II)] Complexes. Ferromagnetic Exchange Coupling
Authors: Mégnamisi-Bélombé Michel
Published: July 2006

Variable-temperature magnetic susceptibilities measured from 4.2 to 300 K on the new dimeric clusters indicate ferromagnetic exchange coupling with J=+4.63 cm−1 and J=+0.14 cm−1 for di-μ-bromobis[bromo-(4-chloro-1 ,2-benzoquinonedioxime)copper(II)] and di-μ-chlorobis[chloro-1,2-benzoquinonedioxime)copper(II)], respectively, and antiferromagnetic exchange coupling with J=–0.11 cm−1 for di-μ-bromobis [bromo(1,2-benzoquinonedioxime)copper(II)].
Synthesis and Redaction of 3-Bromoflavanones
Authors: Reddy N J , Sharma T C
Published: July 2006

Bromination of flavanone, 6-methylflavanone, 6-methyl-4′-methoxyflavanone, and 6-methyl-3′,4′-dimethoxyflavanone with pyridinium tribromide in glacial acetic acid gives the corresponding 3-bromoflavanones, which when refluxed with thiourea in ethanol undergo reduction to flavanones.
NMR Studies on Molecular Interactions Involved in Alkali Metal Halide–Amide–Glycol Ternary Systems
Authors: Hamaguchi Naoru , Nakagawa Terumichi , Uno Toyozo
Published: July 2006

Interactions in a ternary solution of alkali metal halide–amide–glycol have been investigated on the basis of NMR measurement of chemical shifts of OH proton of glycol and amidic protons of acetamide. Measurements were carried out with various alkali metal halides (MX, M=Li, Na, K, X=Cl, Br, I) and glycols (mono-, di-, tri-, and tetraethylene glycol). The dependency of the chemical shifts on solute concentration was examined with a ternary solution of potassium iodide–acetamide–ethylene glycol. The addition of alkali metal halide to respective glycols or glycolic solutions of acetamide gave rise to a change in chemical shift values. The observed changes were related to the ionic sizes of cations and anions of alkali metal halides and to the number of oxyethylene units in a glycol molecule. It was found that a large ion induces a higher magnetic field shift of resonance positions of glycolic OH proton and amidic proton at trans position than a small ion, the magnitude of the shift change being almost proportional to the concentration of ion, and halogen anion formed in glycolic solution tending to interact with hydrogen at trans position rather than at cis position. From a comparison with the values for chemical shifts of water proton in aqueous alkali metal halide solution, it is suggested that the contribution of alkali metal halide to the chemical shift changes in glycolic solution is similar to those in aqueous solution.
Determination of Magnetic Susceptibilities of Paramagnetic Gases by an Improved Viscometer Method
Authors: Sueoka Kazuo , Ikeda Toshio
Published: July 2006

An improved viscometer method has been applied to the determination of the magnetic susceptibility of a paramagnetic gas and found to be of use in the analysis of a paramagnetic gas mixed in a diamagnetic gas. The magnetic susceptibilities of oxygen and nitrogen monoxide have been determined to within ±0.5% using a saturated aqueous solution of sodium chloride as the working liquid.
Miexd Monolayers of Long Normal Chain Fatty Acids with Long Normal Chain Esters. I. Fatty Acids–Ethyl Hexadecanoate System
Authors: Matuo Hirosi , Yosida Noriaki , Motomura Kinsi , Matuura Ryohei
Published: July 2006

Surface pressure-area(π-A) curves of the two-component surface films of long normal chain fatty acids with ethyl hexadecanoate were measured at various compositions and temperatures. It was found that the π-A curves of the mixed monolayers vary characteristically with the number of carbon atoms of the film-forming acid. The two-dimensional phase diagrams of these systems and their partial molar enthalpy changes were obtained by taking advantage of the thermodynamic treatment of multicomponent surface films. It was concluded that the chain length of the acid plays an important role in the thermodynamic state of the mixed monolayer.
Phase Transition and Electronic States of Solid Ion Radical Salts
Authors: Iida Yôichi
Published: July 2006

Such crystalline ion radical salts as Würster’s Blue perchlorate and K+  p-Chloranil\ewdot are known to undergo phase transitions in the solid state. There are distinct differences in their optical and magnetic properties between the low- and high-temperature phases. Using Hubbard Hamiltonian, the electronic states of the high-temperature phases of those solid ion radical salts were explained in terms of an infinite non-alternant linear chain model, while those of the low-temperature phases, in terms of a dimer model.