bluuebunny/crossref_metadata_2025 huggingface dataset:
Derivatographic Studies on Transition Metal Complexes. XVIII. Thermal Isomerization of cis-[CrCl2tn2]Cl·0.5H2O in Solid Phase
Authors: Yoshikuni Tadatsugu , Tsuchiya Ryokichi , Uehara Akira , Kyuno Eishin
Published: July 2006

The thermal cis-to-trans isomerization of cis-[CrCl2tn2]Cl·0.5H2O in a solid phase was studied by means of derivatographic and isothermal measurements. It was found that cis-[CrCl2tn2]Cl·0.5H2O in which trimethylenediamine(tn) forms six-membered chelate ring with chromium undergoes isomerization to the trans-complex in contrast with the isomerization of trans-[MX2(diam)2]X·HX·nH2O (M=Co or Cr, X=halogen) to the cis-one in which the diamine (diam) forms five-membered chelate ring with metal M. The isomerization proceeded in anhydrous state. The activation energy of the isomerization of the complex was found to be 163 kJ mol−1 from the isothermal measurements, which is fairly greater than that of the trans-[CoCl2pn2](H5O2)Cl2 and cis-[CoCl2tn2]Cl·H2O. The difference was explained by whether or not water molecule involved as a lattice water contributes to the isomerization.
Derivatographic Studies on Transition Metal Complexes. XIX. Thermal Isomerization of trans-[CrCl2(en)2](H5O2)Cl2 and trans-[CrCl2(pn)2]Cl·1.5H2O in Solid Phase
Authors: Yoshikuni Tadatsugu , Tsuchiya Ryokichi , Uehara Akira , Kyuno Eishin
Published: July 2006

Thermal trans-to-cis isomerization of [CrCl2(en)2](H5O2)Cl2 and [CrCl2(pn)2]Cl·1.5H2O was studied in the solid phase by derivatographic and isothermal measurements. The former complex was found to isomerize in anhydrous state after the complete elimination of hydrogen chloride and water, the latter in the temperature range for dehydration. The activation energies for the isomerization of these two complexes were isothermally estimated to be 202 and 193 kJ mol−1, respectively. The same type of isomerization mechanism is suggested for these complexes, differing from that for the corresponding cobalt(III) complexes in which lattice waters participate.
Stereochemistry of Nucleophilic Addition Reactions. 5. Formation of Stabilized Ylides from Methyl 4,6-O-Benzylidene-2,3-dideoxy-3-nitro-β-d-erythro-hex-2-enopyranoside with Some S-Ylides; An Important Role of the Nitro Group for Stabilization of the Ylides
Authors: Sakakibara Tohru , Sudoh Rokuro , Nakagawa Toshio
Published: July 2006

Treatment of methyl 4,6-O-benzylidene-2,3-dideoxy-3-nitro-β-d-erythro-hex-2-enopyranoside (1) with dimethyloxosulfonium methylide and dimethylsulfonium α-methylphenacylide afforded cyclopropane derivatives, whereas similar reactions with dimethylsulfonium phenacylide and dimethylsulfonium ethoxycarbonylmethylide gave stabilized ylides. In all cases the S-ylides enter the C-2 position of 1 from the side trans to the anomeric methoxyl group. The ylide structures were determined from IR and NMR data and confirmed by transformation into the desulfurized products. Anomalous stability of these ylides are attributed to the delocalization of the negative as well as positive charge over the carbonyl and the nitro group, respectively.
The Benzannelated Annulenones. Syntheses and Properties of 10-Methylbenzo[d]-6,8-bisdehydro[15]annulenone and 12-Methylbenzo[f]-8,10-bisdehydro[15]annulenone
Authors: Ojima J\={u}ro , Shiroishi Y\={u}ji
Published: July 2006

Synthesis of two methylated monobenzannelated bisdehydro[15]annulenones is described. It was found by means of 1H-NMR spectra that the protonated annulenones are diatropic.
Equilibrium Study of the Fe–V–S System by Thermogravimetry
Authors: Wada Hiroaki
Published: July 2006

An equilibrium study of the Fe–V–S system was carried out in the range of log(PS2/atm)=−4 to −0.8 at temperatures between 723 and 1093 K. The gravimetric method was employed by making use of a quartz spring balance. The partial pressure of sulfur was controlled in an N2-sulfur vapor system by temperature regulation. The partial pressure of S2 was calculated from the thermodynamic data, taking account of the existence of different molecular species: S2 through S8. Three kinds of ternary sulfides with different Fe/V ratios were used as starting material. The PS2-T-X relation was established through in situ measurements at high temperatures. It was found that the Fe–V–S system has an extensive ternary solid solution with the NiAs type of fundamental structure.
Magnetic and Spectral Properties of Copper(II) Chloride Complexes of Tridentate Salicylideneamines with ONN Set of Donors
Authors: Muto Yoneichiro , Tokii Tadashi
Published: July 2006

Four complexes with the general formula of Cu[sal·(CH2)n·N(R)R′]Cl (sal=·\overset2O·C6H4·\overset1CH=N·; n=2 and 3; R=H and CH3; R′=CH3) were characterized by elemental analyses, IR and visible reflectance spectra, ESR spectra, and magnetic susceptibilities. The complexes where n=2, Cu[sal·(CH2)2·NHCH3]Cl and Cu[sal·(CH2)2·N(CH3)2]Cl, showed normal paramagnetic behavior. The Cu[sal·(CH2)3·N(CH3)2]Cl complex was obtained in two forms, one red-violet and the other green. The red-violet form showed the usual magnetic behavior expected for a mononuclear copper(II) complex, whereas the green one exhibited the antiferromagnetic behavior typical of binuclear copper(II) complexes. The magnetic properties of these complexes are discussed in terms of structural considerations. The characterization of the Cu[sal·(CH2)3·N(CH3)2Br complex is also reported.
Synthesis and Unusual Properties of Trimethylsilylmethyl, Neopentyl, and Related Alfcylthallium Compounds
Authors: Kurosawa Hideo , Numata Shigeaki , Konishi Toshifumi , Okawara Rokuro
Published: July 2006

Synthesis of some new trimethylsilylmethyl, neopentyl, and isobutylthallium compounds is described. Dialkykhallium halides containing these bulky alkyl substituents were found to be dimeric, in marked contrast to the polymeric dimethylthallium halide analogs. Trimethylsilylmethylthallium diisobutyrate possesses much higher stability than the methyl and ethylthallium analogs. These facts were discussed in terms of the steric bulk of the alkyl groups attached to thallium.
A Synthetic Route to 3,3-Diphenyl-2-indolinone Derivatives
Authors: Sen\={o} Manabu , Shiraishi Shinsaku , Suzuki Yukio , Asahara Teruz\={o}
Published: July 2006

N-Aryl-α-chloro-α,α-diphenylacetimidoyl chlorides were prepared from Schiff bases and dichlorocarbene generated by use of the phase transfer catalyst. Treatment in sulfuric acid gave 3,3-diphenyl-2-indolinone derivatives. The synthetic route to 2-indolinone was found to give a higher overall yield than that by other methods. 2,2-Dichloro-1,3-diphenylaziridine gives α-chloro, α-acetoxy or α-hydroxy-α,α-diphenylacetanilide on treatment with sulfuric acid. Comparison of 2,2-dichloro-1,3-diphenylaziridine, 2,2-dichloro-1,3,3-triphenylaziridine and N-aryl-α-chloro-α,α-diphenylacetimidoyl chloride in their reactivities with sulfuric acid shows that the pathway of the reaction is governed by the character and number of substituents at the reaction center where carbonium ions are developed.
Temperature Effect on the Molecular Weight and the Optical Purity of Anhydropolyaspartic Acid Prepared by Thermal Polycondensation
Authors: Kokufuta Etsuo , Suzuki Shinnichiro , Harada Kaoru
Published: July 2006

Anhydroyplyaspartic acid (APAA) was prepared by the thermal polycondensation of l-aspartic acid in the solid state at 160-220 °C for 5 h. The effect of temperature on molecular weight and optical purity of APAA was investigated. The molecular weight increases rapidly in the temperature range 180–200 °C, the yield of APAA also increasing rapidly. The optical purity deecreases rapidly with rise in temperature from 160–180 °C.
The Reaction of O(3P) Atoms with Indene and Phenanthrene Induced by the γ-Radiolysis of Liquid Carbon Dioxide
Authors: Goto Seizi , Hori Akira , Takamuku Setsuo , Sakurai Hiroshi
Published: July 2006

The γ-radiolysis of liquid CO2 with indene and phenanthrene gives the corresponding oxirane and carbonyl compounds, together with some products which are unexpected on the basis of the reaction of (3P) with aliphatic olefins: (i) the corresponding cyclic carbonate; (ii) 1H-2-benzopyran and a dimer for indene, and (iii) dibenz[b,d]oxepin and 2,2′-biphenyldicarbaldehyde for phenanthrene. The mechanisms of the formation of these products are discussed.
Syntheses of Aromatic Mannich Bases Involving Nitrogen Heterocycles by Means of Amine-exchange Reaction
Authors: Kamogawa Hiroyoshi , Kubota Kuniaki , Nanasawa Masato
Published: July 2006

Amine-exchange reactions of aliphatic Mannich bases involving nitrogen heterocycles, such as 2-(2-dimethylaminoethyl)-substituted pyridine, quinoline, benzothiazole, and 3,3-dimethyl-3H-indole, with arylamines readily provided the corresponding aromatic Mannich bases which are otherwise hardly accessible.
Calorimetric Study of the Glassy State. XIV. Calorimetric Study on Unusual Glass Transition Phenomena in CFCl2–CFCl2
Authors: Kishimoto K\={o}ji , Suga Hiroshi , Seki Syûzô
Published: July 2006

The heat capacities of the glassy crystalline, plastic crystalline, and liquid phases of CFCl2–CFCl2 were measured by an adiabatic calorimeter over a temperature range from 13 to 310 K, with a sample of 99.93% purity. The triple point was determined to be 297.91 K, the enthalpy and entropy of fusion being 3.666 kJ mol−1 and 12.30 J K−1 mol−1, respectively. Three kinds of relaxation phenomena were found during the heat capacity measurement centered at around 60, 90, and 130 K, respectively. The first was attributable to the β relaxation. The second was for primary glass transition, where overall rotation or reorientation of the molecules might be frozen. The third was analyzed by ascribing it to the freezing of conversion between the trans and the gauche conformers of the molecule. Activation enthalpy for the internal rotation and energy difference between the two conformers were determined to be 41 kJ mol−1 and (790±60) J mol−1, respectively. This experiment provides the first example in which three different freedoms of molecular motion are frozen successively at different temperatures as the crystal is cooled down. An effort to get a possible low-temperature ordered crystalline phase was partially successful by long annealing of the crystal. The extremely sluggish nature of the phase transition into the ordered phase will be related with the slow rate of the internal rotation of the molecule below the transition temperature.
Copper(II)-2,2′-Bipyridine-Eriochrome Cyanine R Ternary Complex and Its Application to the Spectrophotometric Determination of Copper(II)
Authors: Ishida Ryoei , Narita Hifumi , Tonosaki Koichi
Published: July 2006

Copper(II) ion reacted with 2,2′-bipyridine (bpy) and Eriochrome Cyanine R (ECR) to give one of two kinds of ternary complexes according to the amount of reagents in a weakly basic medium. The combining ratios of three components in the complexes were estimated to be Cu(II): bpy: ECR= 1 : 1 : 2 and 1 : 1 : 1, respectively, the former having an absorption maximum at 515 nm and the latter at 550 nm. The color development of the 1 : 1 : 2 complex was utilized in the spectrophotometric determination of copper(II) at microgram level. The ternary complex gave a maximum absorbance at 515 nm in the pH range 10.2–10.6. Under optimum pH, 2,2′-bipyridine and Eriochrome Cyanine R concentrations, a linear relationship holds between the absorbance of the complex and copper(II) concentration up to 6×10−5 mol dm−3. The apparent molar absorption coefficient at 515 nm is about 20400 dm3 mol−1 cm−1, corresponding to Sandell’s sensitivity index of 0.0031 μg cm−2.
Conditions for the Precipitation of Heavy Metals from Wastewater by the Lime Sulfurated Solution (Calcium Polysulfide) Process
Authors: Aratani Toshiro , Yahikozawa Kiyochika , Matoba Hitoshi , Yasuhara Shigeki , Yano Takeo
Published: July 2006

A new chemical precipitation process utilizing CaSx solution as a single coagulant was tested for the removal of heavy metals from a batch stirred vessel. The precipitation of heavy metals from the simulated wastewater was investigated under varing conditions of pH, temperature, and heavy metal concentrations. Several agitating speeds were studied for the gases (atmospheric air and CO2 gas) blown into the water to decompose the coagulant (CaSx). The findings are as follows: Heavy metal removal in keeping with the water quality standards in Japan was achieved for the simulated wastewater having pH’s between 3 and 11, and the temperatures from 10 to 85 °C. The agitating speed for optimum removal was found to be 10 Hz. More than 250 ppm of the initial heavy metal concentration gives sufficient removal at stoichiometric quantities of coagulant, while less than 50 ppm of the initial concentration results in rather poor removal owing to the colloidal properties of the metal sulfide or hydroxide. For low concentrations of heavy metals, several units of the coagulant over stoichiometric amount are necessary for sufficient precipitation to achieve the water quality standards.
Reactions of 4H-Pyran-4-thiones with Ammonia, Hydrazine, and Guanidine
Authors: Besso Hiromichi , Imafuku Kimiaki , Matsumura Hisashi
Published: July 2006

The reaction of 4H-pyran-4-thiones with ammonia gave 4(1H)-pyridinethiones or bis(4-pyridyl) disulfide, while that of 3-methoxy-2-methyl-4H-pyran-4-thione with guanidine gave the 1,3-thiazine derivative. 4H-Pyran-4-thiones reacted with hydrazine to afford pyridazines, pyrazoles, and 1-amino-4(1H)-pyridinethiones. 4H-Pyran-4-thiones having the hydroxyl group in the β-position gave the pyridazine derivatives.
Solvent Effects on the Photoamination of 1-Amino-2,4-dibromoanthra- quinone. I. Photoamination in Benzene via Intramolecular Charge Transfer Excited Triplet State
Authors: Inoue Haruo , Hida Mitsuhiko
Published: July 2006

The bromine atom at the 4 position of 1-amino-2,4-dibromoanthraquinone (1) was substituted by butylamine and aniline by the irradiation of visible light. In ethanol the dissolved oxygen promoted the reaction and anthracene, a triplet quencher, had little effect. In benzene, the dissolved oxygen retarded the reaction and anthracene had a considerable quenching effect. Kinetic analysis indicated that in ethanol the photoamination of 1 proceeds mainly through the interaction of 1 in S1(1CT) with the ground state oxygen, while in benzene it does through the T1(3CT) of 1 without the aid of oxygen. The detailed reaction mechanism in benzene has been discussed and the rate constant of each process including the deactivation constant of the upper excited T2(3nπ*) level evaluated.
Autoxidation Reactions of Hydrocarbons Catalyzed by Co(II) Tetra(p-tolyl)porphyrin
Authors: Ohkatsu Yasukazu , Tsuruta Teiji
Published: July 2006

Autoxidation reactions of saturated and unsaturated hydrocarbons were carried out using Co(II) tetra(p-tolyl)porphyrin as the catalyst in ethyl acetate at 30°C The Co(II) complex activated the oxygen molecule to the superoxide ion, which abstracted a hydrogen atom from a saturated hydrocarbon or added to the double bond of an unsaturated hydrocarbon, to initiate autoxidation. The reactivity of the activated oxygen molecule was found at the site of the free radical rather than that of the anion thereof. The reactivities were compared with those of superoxide ions derived from other origins.
The Preparation of a Seven-Coordinate Dimethyllead(IV) Complex, (CH3)2Pb(gbha)(H2O), and Ionic Dissociation of the Coordinated Water
Authors: Majima Tetsuro , Kawasaki Yoshikane
Published: July 2006

A seven-coordinate dimethyllead(IV) complex, (CH3)2Pb(gbha)(H2O), was prepared. From spectroscopic studies the water molecule in the complex was found to coordinate rather strongly to the lead atom as the seventh ligand. An interesting feature of the complex is that the dissociation of a proton from the coordinated water occurs in such coordinating solvents as DMSO and HMPA.
A-Substituted 5β-Steroids. VIII. Synthesis and Bromination of 3-Alkyl-5β-cholestan-2-one
Authors: Satoh J Yasuo , Horiuchi C Akira , Hagitani Akira
Published: July 2006

3α-Alkyl-5β-cholestan-2-one (R=CH3, C2H5, and CH3CH2CH2) was prepared by the direct alkylation of 5β-cholestan-2-one with alkyl iodide and potassium t-butoxide in a reflux of t-butyl alcohol-benzene. The 3α-benzyl ketone was prepared from 5β-cholestan-2-one by aldol condensation with benzaldehyde in the presence of potassium hydroxide, followed by hydrogenation of the condensation product. The bromination of these 3α-alkyl ketones gave 3β-bromo-3α-alkyl-5β-cholestan-2-ones.
Vibrational Fine Structure of the Ligand Field Absorption Band of Halogenoammine Cobalt(III) Complexes
Authors: Fukuda Kunimasa , Urushiyama Akio
Published: July 2006

The crystal absorption spectra of some halogenoammine complexes of Co(III) were measured at liquid helium temperature. The vibrational fine structures observed for the spin-allowed ligand field bands were interpreted in terms of a vibronic intensity mechanism in comparision with the vibrational frequencies of the skeletons. It was found that all the vibrational fine structures consist of the uniquantal progression of totally symmetric Co–N stretching vibration. This suggests that the equilibrium Co–N distances of these complexes are elongated in the ligand field electronic excited state as compared with those in the ground state.
Fluorescence Spectra of 1,1′-Binaphthyl and Related Compounds at High Pressures
Authors: Hara Yoji , Nicol Malcolm F
Published: July 2006

Relative to the related compounds 2,2′-binaphthyl (I) and 2,2′-dimethoxy-1,1′-binaphthyl (II), the pressure dependence of the fluorescence of crystals of 1,1′-binaphthyl (III) is complex. Compression to 30 kbar at room temperature shifts the 1La fluorescence spectra of all three compounds to longer wavelength but, for I and II does not change the intensity profile, except for some 0-0 reabsorption. For III, this red shift characteristic of 1La fluorescence spectra is dominated by growth of new bands about 3.5 to 5.0×103 cm−1 to lower energy. Similar new bands are observed when 1,1′-binaphthyl crystals are compressed at 90 K or resolved crystals are compressed at room temperature, but are not found to 30 kbar for dilute solutions of 1,1′-binaphthyl in polyacrylonitrile. The planes of adjacent naphthyl residues along \overrightarrowb in the crystal are parallel but offset, the normal distance between planes being 3.55 Å; Raman spectra provide no evidence for a structural phase transformation upon compression. These new bands are assigned as the binaphthyl excimer.
Hydrogen-Deuterium Exchange Rate between a Peptide Group and an Aqueous Solvent as Determined by a Stopped-Flow Ultraviolet Spectrophotometry
Authors: Takahashi Tetsuo , Nakanishi Mamoru , Tsuboi Masamichi
Published: July 2006

When an 1H2O solution of N-methylacetamide was rapidly mixed with 2H2O, a time-dependent decrease of the ultraviolet absorbance at 227 nm was observed. This was not the case with N,N-dimethylacetamide. Hence, the time-dependent decrease in absorbance was attributed to be caused by the deuteration (NH→ND) reaction of N-methylacetamide. This provides an appropriate method for determining deuteration rate of the peptide group in a polypeptide or in a protein. By this method the deuteration rate of poly-d,l-alanine has been examined in the pH=5—8 and temperature=10—40 °C range. In this range, the deuteration was found to proceed always as a single first-order reaction, and the rate constant ke is expressed within an experimental error as ke=6.4×10(6+pH−3850⁄T) This is to be used as a standard rate-constant value in estimating the attenuation factor γj=kj⁄ke of a given peptide group (j) in a protein molecule whose rate constant value is kj.
Branched-chain Sugars. XII. The Stereoselectivities in the Reaction of Methyl 4,6-O-Benzylidene-α- and -β-d-hexopyranosid-3-uloses with Diazomethane
Authors: Sato Ken-ichi , Yoshimura Juji
Published: July 2006

The stereoselectivities in the diazomethane reaction of methyl 4,6-O-benzylidene-2-O-methyl-α-d-ribo-hexopyranosid-3-ulose (2), its 2-epimer (3), β-anomer of 2 and the corresponding 2-O-Benzoyl derivative were examined, in comparison with those in the Grignard reaction and sodium borohydride reduction. The complemental stereoselectivity of diazomethane reaction in the case of 2 and 3 indicated that the electrostatic attractive effect in the transition state between diazomethyl cation and the axial methoxyl oxygen at the α-position to carbonyl function in 3 is much stronger than that at β-position which is predominat in the case of 2. In cases of β-anomers having no axial oxygen, stereoselectivies were preferentially controlled by the usual steric factors.
A Stereoselective Rule for the Cross-bicyclization in Linear Conjugated Polyenes
Authors: Tanaka Kazuyoshi , Fukui Kenichi
Published: July 2006

A concept of the cross-bicyclization complementary to that of the cycloaddition is defined for interpreting the mechanism of the simultaneous bicyclizations in linear conjugated polyenes based on the perturbation treatment in the frame of Hückel MO’s. Stereoselective modes in thermal and photo-induced reactions are shown to depend on the sign of the bond-bond-polarizability, Πrs,tu, of the concerned polyene, where r, s, t, and u refer to the atomic positions at which the bicyclization occurs. From the properties of Πrs,tu of linear conjugated polyenes, these modes are simply determined by the relationship among r, s, t, and u in thermal cases, but not in photo-induced ones. The predicted stereoselective modes are discussed in line with experimental observations. It is demonstrated that the “symmetry-disfavored” reactions inferred from the usual cycloaddition mechanism can be interpreted as the concerted cross-bicyclization reactions.
Molecular Structure and Conformation of Ethyl Methyl Ether as Studied by Gas Electron Diffraction
Authors: Oyanagi Kazuko , Kuchitsu Kozo
Published: July 2006

The bond distances (rg) and angles (rα) in ethyl methyl ether have been determined by gas electron diffraction as follows: average of C(methyl)–O and C(methylene)–O=1.418±0.002 Å, C–C=1.520±0.004 Å, C–H=1.118±0.004 Å, ∠C–O–C=111.9±0.5°, ∠O–C–C=109.4±0.3°, ∠H–C–H=109.0±0.4°, where uncertainties represent estimated limits of experimental error. The two rg(C–O) distances have been estimated independently with the aid of the rotational constants for the trans conformer reported by Hayashi et al.: C(methyl)–O=1.413±0.009 Å and C(methylene)–O=1.422±0.007 Å. The dihedral angle for the gauche conformer, 84±6°, and the relative abundance of the trans and gauche conformers in the gas phase at 20 °C, nt⁄(nt+ng)=0.80±0.08, have also been determined.
The Two n,π* Transitions of Monohalogenoanthraquinones
Authors: Matsuzaki Sanae Y , Kuboyama Akira
Published: July 2006

The n,π* absorption and phosphorescence spectra of 1-fluoro-, 2-fluoro, 1-chloro-, 2-chloro-, 1-bromo-, and 2-bromoanthraquinones were studied in solutions, mainly at 77 K. These phosphorescence spectra and their lifetimes resemble those of anthraquinone (AQ), except for those of 1-F-AQ. The phosphorescence spectrum of 1-F-AQ is at longer wavelengths than that of AQ, and its lifetime is 0.8 ms in the methylcyclohexane solution, much shorter than that of AQ. All of the 1-halogenoanthraquinones showed two distinct n,π* singlet-singlet absorption bands at 77 K, and 1-Br-AQ showed an additional band of the n,π* singlet-triplet transition at 492 nm. The low-energy n,π* singlet and triplet states of these compounds are discussed on the basis of these experimental results.
12,13-Epoxy-C-nor-D-homosteroids. I. The Synthesis and Stereochemistry of 17α-Acetyl-12,13-epoxyetiojervanes
Authors: Murai Akio , Sasamori Hiroshi , Masamune Tadashi
Published: July 2006

Several 11-substituted 17α-acetyl-12,13-epoxyetiojervanes were prepared from jervine. Jervine was degraded by a known process into (17E)-17-ethyletiojerva-4,12,17(20)-triene-3,l 1-dione, which on epoxidation followed by acid treatment gave 17α-ethyletiojerva-4,12-diene-3,l 1,20-trione as the main product. Acetalization of the carbonyl groups, at C3 and C20 of the triketone and subsequent hydride reduction produced two 11-epimeric alcohols, which on hydrolysis afforded 17α-ethyl-11α-hydroxyetiojerva-4,12-diene-3,20-dione and its 11β-hydroxy epimer. These alcohols and their acetates were oxidized with perbenzoic acid and/or t-butyl hydroperoxide to give the epoxides. The structure and configuration of these epoxides and the synthetic intermediates were determined on the basis of the chemical and spectral evidence.
The Reaction of Azidotriazines with Pyridines and Triphenylphosphine
Authors: Fujinuma Kenji , Hashida Yoji , Matsui Kohji
Published: July 2006

2-Azido-4,6-dimethoxy-1,3,5-triazine (1a) gave an adduct with pyridine in a molar ratio of 1 : 1. On the contrary, 2-azido-4,6-bis(dimethylamino)-1,3,5-triazine (1b) did not react with pyridine. Similarly, 1a gave an adduct with 3-methylpyridine, whereas in the reactions of 1a with 2-methyl-, 4-methyl-, and 2,6-dimethylpyridines, 2-amino-4,6-dimethoxy-1,3,5-triazine was obtained instead of the adduct. On the other hand, 1a and 1b gave the corresponding triazinyliminophosphoranes with triphenylphosphine.
Syntheses of 5-Hydroxyflavone-Transition Metal Complexes
Authors: Hiraki Katsuma , Onishi Masayoshi , Ikeda Tsuyoshi , Tomioka Kazuko , Obayashi Yayoi
Published: July 2006

New complexes [M(hofl)2(OH2)n] (Hhofl=5-hydroxyflavone; M=Co and Ni, n=2; M=Cu, n=1 and 0) and [M(hofl)3] (M=V and Fe) were synthesized and characterized by IR and electronic absorption spectroscopy. Polynuclear ethoxo(5-hydroxyflavonato)metal(II) complexes of cobalt and copper were also prepared.
Synthesis Using Pyridinium N-Ylides. I. Synthesis and Some Reactions of Substituted 1-(Acetylimino)pyridinium Ylides
Authors: Kakehi Akikazu , Ito Suketaka , Konno Yoshiaki , Maeda Toshiaki
Published: July 2006

Pyridinium N-imines reacted smoothly with diethyl malonate and ethyl cyanoacetate in ethanol at room temperature to give the corresponding 1-(ethoxycarbonylacetylimino)- and 1-(cyanoacetylimino)pyridinium ylides in 59–87% yields. These ylides were converted to 1-(acetylimino)pyridinium ylide derivatives by the treatment with acetic anhydride. The alkaline treatment of the pyridinium salts which were prepared by the alkylation of the N-ylides with alkyl halides, gave the corresponding 3-ethoxycarbonyl- and 3-cyano-1,2-dihydropyrazolo-[1,5-a]pyridin-2-one derivatives in 8–51% yields.
Hydrates of Organic Compounds. III. The Formation of Clathrate-like Hydrates of Tetrabutylammonium Dicarboxylates
Authors: Nakayama Haruo , Watanabe Kazuichi
Published: July 2006

The solid-liquid phase diagrams for the binary mixtures of water with 20 tetrabutylammonium dicarboxylates, [(n-C4H9)4N]2OOC–R–COO (R=methylene chain ranging from 0 to 10 carbon atoms; methylene chain containing substituted groups such as –CH3, –C2H5, –NH2, and –OH; and –C6H4– (three phthalate isomers)), have been investigated to see the effect of dicarboxylate anions on the formation of clathrate-like hydrates. It has been found that, with only the one exception of the dodecanedioate, all the other salts form hydrates which have large hydration numbers. Judging from these large hydration numbers, they are believed to be clathrate-like hydrates. From the relationship between the hydration numbers and the melting points, these hydrates can be classified into three groups at least. All the hydrates other than those of oxalate and of terephthalate are newly found in this study.
Optical and Magnetic Properties of Solid Anion Radical Salts Derived from Halogen-Substituted p-Benzoquinones
Authors: Iida Yôichi
Published: July 2006

Crystalline anion radical salts derived from halogen-substituted p-benzoquinones are known to show charge-transfer transition between anion radicals in the low-energy region and to possess antiferromagnetic spin exchange interaction between the anion radicals. Using Hubbard Hamiltonian, the optical and magnetic properties of Na+  p-Chloranil\ewdot were explained in terms of a dimer model, while those of K+  p-Chloranil\ewdot and K+  p-Bromanil\ewdot, in terms of an infinite non-alternant linear chain model.
Absorption and Circular Dichroism Spectra of Cobalt(III) Complexes Containing N,N-Dimethylethylenediamine
Authors: Akamatsu Keiji , Shimura Yoichi
Published: July 2006

Nine new cobalt(III) complexes containing N,N-dimethylethylenediamine are prepared. The geometrical configurations of isomers are assigned on the basis of their visible and ultraviolet absorption spectra, proton magnetic resonance spectra, and the optical resolution of the chiral isomers. The absorption and circular dichroism spectra are discussed in comparison with those of the corresponding complexes containing ethylenediamine, N-methylethylenediamine, N,N′-dimethylethylenediamine, or tris-2-(aminoethyl)amine.
Synthesis of 1,4-Dithiafulvenes and 1,4-Dithiafulvalenes by Carbonyl Olefination Using 2-Dimethoxyphosphinyl-1,3-benzodithiole
Authors: Akiba Kin-ya , Ishikawa Kiyofumi , Inamoto Naoki
Published: July 2006

The reactions of 1,3-dithiolylium salts with tertiary phosphines and trialkyl phosphites in dry acetonitrile gave the corresponding phosphonium salts and the phosphonates respectively in high yields. Both 2-triphenylphosphonio-1,3-benzodithiole tetrafluoroborate and 2-dimethoxyphosphinyl-1,3-benzodithiole were deprotonated with butyllithium in THF at −78 °C and the resulting phosphorane (A) and the phosphonate carbanion (B) reacted with a variety of carbonyl compounds to give 1,4-benzodithiafulvenes in 74–98% yields. Moreover, B reacted with conjugated cyclic ketones (5) such as dibenzo[a,d]cyclohepten-5-one, 10H-9-thiaanthracen-10-one, 9-alkyl-9,10-dihydro-9-azaanthracen-10-one, 9-fluorenone, and so on to give 1,4-benzodithiafulvalenes (6) in 73–96% yields. The UV spectral data of 6 were discussed in comparison with those of 5.
Variation of Transport Properties as Functions of Temperature and Composition in Glass-forming Melts — An Isoenergic Equation
Authors: Islam Nurul , Kumar Satendra , Singh Kunwar Pal
Published: July 2006

Measurements of density, ρ, viscosity, η, and electrical conductance, Λ, in glass-forming molten mixtures of manganese(II) chloride-tetrabutylammonium bromide were made as functions of temperature and composition. The non-Arrhenius temperature dependence of transport properties has been discussed in terms of equations based on the free-volume model. Composition dependence of viscosities has been explained satisfactorily through a parabolic equation, η=p+qN+rN2+sN3, where p, q, r, and s are the empirical parameters and N is the mole fraction of the solute. The minimum in the viscosity isotherms has been observed at N=−q⁄2r. A better applicability of isoenergic equation, Y(=φorΛ)=(A0Y−Q1YN)c−1⁄2(T0(0)+(Q2N)−1⁄2exp[−k1Y⁄(T0(0)+Q2N)(c−1)] over an isothermal equation (both based upon free volume model) in explaining the transport process in all the glass-forming melts has been emphasized.
The Use of Zinc/Silver Couple in the Cyclocoupling Reaction of Polybromo Ketones and Furan
Authors: Sato Tsuneo , Noyori Ryoji
Published: July 2006

The title 3+4→7 reaction, followed by Zn/Cu couple reduction in methanol, affords 8-oxabicyclo[3.2.1]oct-6-en-3-ones in satisfactory yields.
An Upper Limit to the Excited Electron-Cation Recombination Lifetimes of Trapped Electrons in Ethanol and 2-Methyl-tetrahydrofuran Glasses at 4 and 77 K
Authors: Ogasawara Masaaki , Kevan Larry
Published: July 2006

N,N,N′,N′-Tetramethyl-p-phenylenediamine (TMPD) fluorescence lifetimes in 2-methyltetrahydrofuran (MTHF) glass at 77 K (13.5 ns) and in ethanol glass at 77 K (12.3 ns) and 4 K (11.5 ns) were measured using 347 nm excitation from a frequency doubled ruby laser. Trapped electrons and TMPD+ were generated in these matrices by photoionization and the recombination fluorescence stimulated by 694 nm laser light was found, within an experimental limit of 1 ns, to occur with the same lifetime as the directly excited fluorescence. A convolution analysis indicates that the electron-cation recombination lifetimes are ≤1 ns in all these matrices at the temperatures given. It is also suggested that a lower limit for the electron mobility of 0.005 cm2 V−1 s−1 is implied by these data.
The “Overcondensation” of Phosphate Ions and the Formation of Conjugate Metal Oxide upon the Thermal Dehydration-condensation of Hydrogenorthophosphates
Authors: Kawazoe Hiroshi , Ametani Kazuo , Imai Masahiko , Kanazawa Takafumi
Published: July 2006

On the thermal reaction of H3PO4 or NH4H2PO4 with metal salts, such as Na2CO3 or Mg(OH)2, the “overcondensation” of the phosphate anions and the conjugate formation of metal oxide were observed. The “overcondensation” was defined as a formation reaction of the phosphate with a larger polymerization degree than that of the product to be expected from the [MO or M2O]/[P2O5] mole ratio of the starting mixtures. The “overcondensed” tetrametaphosphate and the conjugate oxide, magnesium oxide, were detected on the thermal condensation of MgHPO4·3H2O and of a mixture of NH4H2PO4 or H3PO4 and Mg(OH)2. The “overcondensed” tripoly- and trimeta-phosphate were found in the course of the formation reaction of Na pyrophosphate from a mixture of Na2CO3 and NH4H2PO4.
Synthesis, Reactions and Catalytic Properties of Stable Alkoxocopper, Phenoxocopper and Related Copper Complexes Containing Triphenylphosphine Ligands
Authors: Kubota Minoru , Yamamoto Akio
Published: July 2006

A variety of new alkoxocopper and phenoxocopper(I) complexes containing triphenylphosphine ligands have been prepared by the reactions of methylbis(triphenylphosphine)copper(I) etherate (I) with the corresponding alcohols and phenols. The isolated complexes were characterized by elemental analysis, IR and NMR spectroscopy and chemical reactions. The reactions of the alkoxocopper and phenoxocopper complexes with alkyl halides and acyl halides or carboxylic anhydrides yield ethers and carboxylic esters, respectively. The stoichiometric exchange reactions of the alkoxo group in the alkoxocopper complexes with carboxylic esters proceed smoothly and the alkoxocopper complexes were found to act as excellent catalysts for the transesterifications between carboxylic esters and alcohols. The exchange reactions take place also between the alkoxocopper complexes and phenols or thiols producing phenoxocopper or alkylthiocopper complexes with the liberation of alcohols. Amides and nitromethane react with the alkoxocopper complexes releasing alcohols to give N-bonded amidocopper and O-bonded acinitrocopper complexes, respectively. The thermolysis of the alkoxocopper complexes in various solvents were studied and the mechanism and the factors influencing the course of thermolysis discussed.
A Dimeric Structure of Dimethyllead(IV) Complexes with ONO Tridentate Schiff-base Ligands and the Interaction of These Complexes with Donor Solvents
Authors: Majima Tetsuro , Kawasaki Yoshikane
Published: July 2006

From measurements of the molecular weights, dimethyllead(IV) complexes with ONO tridentate Schiff-base ligands, 2-(2-oxidobenzylideneamino)phenolatos, were found to have dimeric six-coordinate structure in CHCl3, in which either one of the two oxygen atoms in the ligands bridges the lead atoms. The 2J(207Pb–CH3) values increase and the δ(Pb–CH3) values shift to a higher magnetic field with an increase in the donor strength of the solvents. Linear relationships between the 2J(207Pb–CH3) and δ(Pb–CH3) values and Hammett’s σ values of the substituents on the Schiff-base ligands were obtained. These results suggest that the complexes form monomerically as a result of coordination with one and/or two solvent molecules in such donor solvents as DMSO and HMPA, and that the 2J(207Pb–CH3) values is dependent mainly on the change in the positive charge on the lead atom: the change in the mean excitation energy, ΔE, in the Fermi contact term.
The Solution Behavior of Thenoyltrifluoroacetone in Alcoholic Solvents
Authors: Shibuya Hidenori , Watarai Hitoshi , Suzuki Nobuo
Published: July 2006

The solution behavior of thenoyltrifluoroacetone (TTA) has been investigated in a series of higher alcohols which are often used in solvent extraction by means of UV and NMR spectrometries. It was experimentally confirmed that TTA exists in the enol and hemiacetal forms in dehydrated alcohol, while in wet alcohol we should also take a hydrate form into consideration. The fractions of the species at equilibrium were determined, and their dependencies on the water concentration and on the solvent properties, i.e., the dielectric constant and the solubility parameter, were examined. The interconversion rate between the enol and hemiacetal forms were also observed as a function of the water concentration.
A New Catalyst for the Low Temperature Oxo Process with the Characteristic of Easy Separation
Authors: Matsuda Akio , Shin Shigemitsu , Nakayama Jun-ichi , Bando Ken-ichiro , Murata Kazuhisa
Published: July 2006

A new type of catalyst, a cobalt carbonyl-complex has been found for homogeneous hydroformylation. The complex has been prepared from Co2(CO)8 and the ethylene glycol diester of 3-(2-pyridyl)propionic acid as a ligand. The catalyst is active even at the low temperature of 50 °C and very low carbon monoxide pressure range of less than 1 kg/cm2. On subsequent cooling it separates from the reaction product. The ligand was prepared by the hydroesterification of 2-vinylpyridine with carbon monoxide and methanol (or ethanol), followed by the trans-esterification with ethylene glycol. The effect of the partial pressures of carbon monoxide and hydrogen on the product composition and on the recovery of the catalyst was examined. The catalytic activity of the new complex is considerably higher than that of Co2(CO)8 at a lower temperature. The selectivity to linear aldehyde in the presence of new complex is significantly higher than in the presence of Co2(CO)8 when the hydrogen to carbon monoxide ratio (H2/CO) in gas phase is high, but this difference in selectivity is small when the above gas ratio is normal. The new complex can be applied as catalyst for removal of carbon monoxide in hydrogen by means of oxo process.
Metal-catalyzed Organic Photoreactions. The Photooxidation of Olefins in the Presence of Uranyl Acetate
Authors: Murayama Eigoro , Sato Tadashi
Published: July 2006

The photooxidation of olefins in pyridine in the presence of uranyl acetate afforded β-hiydroxy hydroperoxides. It was confirmed by spectroscopic studies and isotope-incorporation experiments that (1) the stereochemistry of the hydroxyl and hydroperoxyl groups in the β-hiydroxy hydroperoxides was trans, (2) the hydroxyl group was added to the less substituted carbon of the double bond, and (3) the oxygen atom in the hydroxyl group originated mainly from the water molecule, while the oxygen atoms in the hydroperoxyl group originated mainly from molecular oxygen. From these results, we proposed a reaction scheme of: (i) the formation of the hydroxyl radical from water by uranyl acetate-catalyzed photolysis, (ii) the addition of the hydroxyl radical to the double bond, (iii) the combination of the resulted radical with molecular oxygen, and (iv) the hydrogen abstraction of the peroxyl radical to give the product. The scheme was further supported by the photoreaction of 2-methyl-2-butene with bromotrichloromethane in the presence of uranyl acetate, which afforded 3-bromo-3-methyl-2-butanol as the major product.
A Convenient Synthesis of 2-Substituted 3-Nitro-2H-chromene Derivatives
Authors: Sakakibara Tohru , Koezuka Masaru , Sudoh Rokuro
Published: July 2006

On reaction with salicylaldehyde, ω-nitrostyrene and 4,6-dimethoxy-5-(2-nitrovinyl)pyrimidine gave a mixture of 3-nitro-4-hydroxyflavan and 3-nitro-2-phenyl-2H-chromene or 2-(4,6-dimethoxy-5-pyrimidinyl)-3-nitro-2H-chromene, respectively, whereas 4,6-dichloro-5-(2-nitrovinyl)pyrimidine afforded substitution products: 4-chloro-6-(2-formylphenoxy)-5-(2-nitrovinyl)pyrimidine and 4,6-bis(2-formylphenoxy)-5-(2-nitrovinyl)pyrimidine.
Refractive Indices and Polarizabilities of Several Molten Rare Earth Chlorides
Authors: Mochinaga Junichi , Igarashi Kazuo , Aoki Toshio , Iwadate Yasuhiko
Published: July 2006

Refractive indices of molten LaCl3, PrCl3, NdCl3, DyCl3, and YCl3 were measured by the cylindrical lens method. The measurements were carried out with the lights of four wavelengths, and the refractive indices so obtained were represented by empirical equations as linear functions of temperature. From the data molar refractivities were calculated. The refractive indices at infinite wavelength were calculated by use of Cauchy’s relation for dispersion, and electronic polarizabilities were obtained for the salt molecules in molten state, and also the electronic polarizabilities of La3+, Pr3+, Dy3+, and Y3+ ions in the melts were obtained.
Temperature Programmed Desorption Study of Water Adsorbed on Metal Oxides. I. Anatase and Rutile
Authors: Egashira Makoto , Kawasumi Shohachi , Kagawa Shuichi , Seiyama Tetsuro
Published: July 2006

The adsorbed state of water on TiO2 was studied by temperature programmed desorption (TPD) in the range 0–1000 °C. Pure anatase and rutile samples, the TPD spectra of water from which were not affected by any contaminant, could be obtained by the hydrolysis of titanium oxalate and tetrachloride solutions, respectively. Two desorption peaks were observed for anatase with the peak maxima at 69–127 (I) and 191–256 °C (II), and three for rutile at 32–90 (I), 188–265 (II), and 310–356 °C (III). The sum of adsorbed amounts for peaks II, and III are within a monolayer coverage, that of peak I exceeding it. The enthalpies of adsorption were evaluated to be 36 and 55–69kJ·mol−1 for peaks I and II of anatase, and 36, 64, and 104 kj·mol−1 for peaks I, II, and III of rutile, respectively. From these results, the corresponding adsorbed species of peak I was tentatively assigned to physical adsorption, that of peak II to chemisorption on surface oxygen ion by hydrogen bond, and that of peak III to chemisortpion on Ti4+ by the coordination of oxygen atom of water molecule. The last species may be dissociated into surface OH groups.
Carrier Effect of Reversed Micelle on Imidazole Catalyst
Authors: Kon-no Kijiro , Kitahara Ayao , Fujiwara Masami
Published: July 2006

The reversed micelles of neither didodecyldimethyl ammonium bromide(DDAB) nor sodium 1,4-bis(2-ethylhexyl) 2-sulfonatosuccinate(AOT) catalyse the decomposition of p-nitrophenyl acetate(PNPA) by themselves. However, these reversed micelles increase the action of imidazole in the decomposition of PNPA by solubilizing it. This interesting carrier effect of the reversed micelle on imidazole was investigated in both anhydrous and hydrous systems. The carrier effect of DDAB was greater than that of AOT. This difference was related to the different interaction between imidazole and each of the surfactants. The existence of the different interaction was made clear from the investigation on the change of chemical shift of the H(1) proton of imidazole upon solubilization by the reversed micelle. The mechanism of the decomposition of PNPA was partially explained from NMR measurements. Aminolysis occurred in anhydrous systems and hydrolysis in hydrous systems. Water pooled in the reversed micelle was more effective than bulk water in enhancing the catalytic effect of imidazole.
The Crystal and Molecular Structure of Daphnetin 8-β-d-Glucopyranoside Dihydrate Isolated from Daphne odora
Authors: Ueno Katsuhiko , Saito Norio , Sato Mitsuhiko
Published: July 2006

The crystal structure of daphnetin 8-β-d-glucopyranoside dihydrate has been determined by the X-ray method. The crystal is monoclinic, space group P21, with the lattice parameters a=7.773(1), b=22.478(5), c=4.715(1) Å, β=99.77(2)°, and Z=2. The structure was determined by the direct method and refined by least-squares to a final R of 0.041 for 2690 observed reflexions. The daphnetin moiety is approximately planar, and little effect from glucosylation is observed in the bond lengths and angles, compared with daphnetin itself. The glucopyranoside is in C1 chair conformation, with the ring torsion angles ranging from 48 to 66°. The anomeric C–O bond is twisted by 78.2° against the coumarin plane, which is the largest value in aromatic glycopyranosides so far reported and which is concomitant with a small valence angle, 114.4°, at the oxygen atom linking the coumarin and the glucose group.
X-Ray Diffraction Studies on the Structures of Tetraammine- and Triamminemonochlorozinc(II) Ions in Aqueous Solution
Authors: Yamaguchi Toshio , Ohtaki Hitoshi
Published: July 2006

X-Ray scattering measurements have been carried out on ammoniacal aqueous solutions of zinc(II) chloride at the NH3/Zn mole ratios of 3.8, 5.0, and 6.6. The radial distribution curves show that the tetraamminezinc(II) complex is formed as the main species, the ammonia molecules within the complex being tetrahedrally coordinated to zinc(II) ion at a distance of (2.03±0.02) Å. Analysis of the radial distribution curve obtained for the solution at the NH3/Zn ratio of 3.8 indicates formation of the mixed complex ZnCl(NH3)3+, the Zn–NH3 and Zn–Cl bond lengths being (2.00±0.03) and (2.30±0.03) Å, respectively.
An X-Ray Photoelectron Spectroscopic Study of Dioxime Metal Complexes
Authors: Yoshida Tooru
Published: July 2006

The O(1s) and N(1s) electron-binding energies were measured for the dioxime complexes of several transition metals by means of the X-ray photoelectron spectroscopic method. On the basis of their chemical shifts, the strength of the intramolecular hydrogen bonds and the charge distribution around the nitrogen atoms in the complexes are discussed. Two kinds of oxygen atoms were observed for all the complexes, and their binding energy differences were in the range of 1.3–1.9 eV. This difference was found to decrease with the increase in the strength of the hydrogen bonds. However, only one kind of nitrogen atom was observed for all the compounds except one. The N(1s) chemical shifts were in the range of 0.2–0.8 eV, and were found to increase slightly in the order of CuII<NiII<PdII<PtII.
3β-Angeloyloxy-10β-hydroxy-9β-senecioyloxyfuranoeremophilane and 3β-Angeloyloxy-10β-hydroxyfuranoeremophilane. New Furanoeremophilane Derivatives from Farfugium japonicum Kitamura
Authors: Nagano Hajime , Takahashi Takeyoshi
Published: July 2006

Two new furanoeremophilane derivatives isolated from Farfugium japonicum Kitamura have been shown to be 3β-angeloyloxy-10β-hydroxy-9β-senecioyloxyfuranoeremophilane and 3β-angeloyloxy-10β-hdroxyfuranoeremophilane.
Formation of Dialkyl α-Siloxybenzylphosphonate via 1,2-Anionic Rearrangement of a Silyl Group
Authors: Sekiguchi Akira , Ikeno Masayuki , Ando Wataru
Published: July 2006

The reactions of silyl phenyl ketones with trialkyl phosphites and dialkyl sodiophosphonates gave dialkyl α-siloxybenzylphosphonates in good yields. The mechanism involves the migration of a silyl group from carbon to anionic oxygen. No deoxygenation of silyl ketone with trialkyl phosphite was observed.
Polymorphism and the Structure of Bis(dichloromethylene)succinic Acid as Studied by Chlorine NQR
Authors: Hashimoto Masao , Mano Koichi , Fujino Akira
Published: July 2006

It was found that bis(dichloromethylne)succinic acid (BDCSA) has two crystal forms, the molecule having an s-trans conformation in each form. A frequency drop of about 1 MHz found for BDCSA might be explained in terms of a short intramolecular contact between the chlorine and oxygen atoms.
Electrochemical Reaction of Organoboranes in the Presence of Propenoic Acid Esters. A Convenient Carboxylic Ester Synthesis from Organoboranes
Authors: Takahashi Yuzuru , Yuasa Kazuma , Tokuda Masao , Itoh Mitsuomi , Suzuki Akira
Published: July 2006

Electrolysis of trialkylboranes using two platinum electrodes in the presence of α,β-unsaturated esters in an acetonitrile solution containing tetraalkylammonium halide as a supporting electrolyte, produces the corresponding alkylated carboxylic acid esters in good yields.