bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of a Glass Electrode in the Potentiometric Study of Acid-Base Equilibria of Zinc and Cadmium Acetates in Acetic Acid
Authors: Sawada Kiyoshi , Nakano Mitsuji , Mori Hidenari , Tanaka Motoharu 
Published: July 2006

Abstract
Potentiometric study of acid-base equilibria of zinc and cadmium acetates in acetic acid was undertaken with a glass electrode filled with a LiCl–HClO4 acetic acid solution. Potentiometric titration of 0.1 m LiClO4 acetic acid solution with perchloric acid and lithium acetate reveals that the glass electrode gives rise to the Nernstian response. The equilibrium constant of the reaction, HClO4+LiOAc \oversetKf\ightleftharpoons LiClO4+HOAc is found as logKf=7.86. The titration of zinc and cadmium acetate with perchloric acid and lithium acetate points to the following equilibria: M(ClO4)2+LiOAc \oversetβ1\ightleftharpoons M(OAc)(ClO4)+ LiClO4, M(ClO4)2+2LiOAc \oversetβ2\ightleftharpoons M(OAc)2+2LiClO4, M(ClO4)2+3LiOAc \oversetβ3\ightleftharpoons LiM(OAc)3+2LiClO4. Logarithmic overall formation constants of the acetato complexes, β1, β2 and β3 were determined as 4.04, 7.00 and 9.2 respectively for zinc, and 3.43, 5.46 and 8.0 respectively for cadmium. In addition zinc forms tetraacetate complex with the overall formation constant of logβ4=12.4.
Synthesis of Chloro(organo-oxy)tin(IV) from Organo-hydroxylic Compound and Tin(II) Chloride
Authors: Masaki Mitsuo , Fukui Kiyoshi , Uchida Izuhiko , Yasuno Hiroshi 
Published: July 2006

Abstract
The reaction of an organo-hydroxylic compound and tin(II) chloride with a chlorine compound containing positively polarizable chlorine was found to yield trichloro(organo-oxy)tin(IV) or its disproportionation products, dichlorobis(organo-oxy)tin(IV) and tin(IV) chloride. The reaction of tin(II) chloride and N-chlorosuccinimide (NCS) with methanol or ethanol afforded methoxy- or ethoxy-trichloro(succinimide)tin(IV) (1), while the reaction with n-butanol led to the formation of dibutoxydichlorotin(IV) (2) and tetrachlorobis(succinimide)tin(IV) (3). The reaction of tin(II) chloride and NCS with alcohols in the presence of cyclohexanone oxime gave dialkoxydichloro(cyclohexanone oxime)tin(IV) (6). Cyclohexanone oxime and hexahydro-2H-azepin-2-one(3,4,5,6-tetrahydro-2H-azepin-7-ol) could be used as the organo-hydroxylic reagent in the reaction, while 1-chloronitrosocyclohexane and N-chlorohexahydro-2H-azepin-2-one were also useful as the chlorine compound. Thus, dichlorobis(cyclohexanone oximato)tin(IV) (9), dichlorobis(hexahydro-2H-azepin-2-onato)tin(IV) (13), and an adduct of 9 with tetrachlorobis(hexahydro-2H-azepin-2-one)tin(IV) (1 : 1) were prepared. Two stable complexes, bis(benzophenone oximato)dichlorobis(hexahydro-2H-azepin-2-one)tin(IV) (15) and dichlorobis(2-pyridinethiolato)tin(IV) (11), were synthesized by the reactions of 13 with benzophenone oxime and 2-pyridinethiol respectively. The complex 13 was also synthesized by the reaction of N-trimethylsilylhexahydro-2H-azepin-2-one with tin (IV) chloride.
The Crystal and Molecular Structure of cis-2,2-Diphenyl-3,4-dichlorothietane
Authors: Kumakura Shigekazu , Kodama Toshiko 
Published: July 2006

Abstract
The crystal structure of cis-2,2-diphenyl-3,4-dichlorothietane has been determined from three-dimensional X-ray data collected by the photographic method. The compound forms monoclinic crystals with a=9.94(1), b=12.56(1), c=12.96(1) Å, β=120.66(8)°, and Z=4 in the space group of P21⁄c. The structure has been refined by the block-diagonal least-squares method to a final R value of 0.10, based on 1578 observed reflections. The conformation of the C–Cl bonds with respect to the thietane ring is (3e4a), consistent with that in solution derived from the dipole moments. The thietane skeleton of the compound is puckered, with a dihedral angle of 151.1°. The two C–S distances are 1.81 Å and 1.89 Å, and the average distance between the C–Cl bonds is 1.785 Å. The C–S and C–Cl bond characters are discussed in terms of the CNDO/2 method. The intermolecular S···S contact of 3.32 Å is remarkably short; it may be explained as a consequence of an attractive interaction between the dipole moments of the molecules.
Studies of 4-Diethylenetriaminemonoacetatocobalt(III) Complexes. I. The Preparation and Identification of 4-Diethylenetriaminemonoacetatocobalt(III) Complexes with Ethylenediamine, Oxalate Ion, or Acetylacetonate Ion as the Additional Ligand
Authors: Kuroda Kashiro , Mori Yoshio , Matsunaga Hitoshi , Kunigita Kazufumi , Watanabe Kiyokatsu 
Published: July 2006

Abstract
The fac(N)- and mer(N)-isomers of 4-diethylenetriaminemonoacetatocobalt(III) complexes with ethylenediamine, the oxalate ion, or the acetylacetonate ion as the additional ligand have been obtained by means of reactions between chloro(4-diethylenetriaminemonoacetato)aquocobalt(III) chloride and the bidentates under different conditions. The geometrical configuration of each isomer has been identified by means of the PMR spectra and the electronic absorption spectra. The methine hydrogen in the acetylacetonato complexes has been replaced with bromine, and the resulting complexes have also been characterized.
Group Interactions in Polyelectrolytes. XI. The Kinetics of N-Methylation of Poly(ethyleneimine)
Authors: Kawabe Hiroshi 
Published: July 2006

Abstract
The N-methylation of polyethyleneimine (PEI) of low and high molecular weights as well as that of diethylenetriamine was investigated kinetically in 50% aqueous ethanol; during the procedure we observed deceleration due to the electrostatic effect of the neighboring charged groups. The rate equation was derived for the N-methylation of PEI, which proceeded in three steps with a marked deceleration beyond quarter-conversion and also beyond half-conversion. In the second and third steps of the N-methylation of PEI, additional energies equivalent to the electrostatic free energies due to the one and the two nearest-neighboring charged groups were required respectively, in addition to the intrinsic activation energy of the first step.
Gas-chromatographic Behavior of C1, C2, and C3-Halocarbons Containing Iodine
Authors: Makide Yoshihiro , Fukumizu Takefumi , Tominaga Takeshi 
Published: July 2006

Abstract
The regularity of the specific retention volume (Vg) in gas chromatography was investigated on a number of C1, C2, and C3 halocarbons containing iodine. The log Vg value was found to correlate with the number of halogen and carbon atoms in the molecule.
The Synthesis of Flemichapparin-A and Its Derivatives
Authors: Yamada Shigetoshi , Ono Futara , Katagiri Takao , Tanaka Juntaro 
Published: July 2006

Abstract
Some chromenochalcones including Flemichapparin-A were synthesized in 53–63% yields from 6-acetyl-5,8-dihydroxy-2,2-dimethylchlomene and benzaldehydes.
Photolysis of Aromatic Oxime Esters. Finding of Aromatic Substitution by Diphenylmethyleneimino Radicals
Authors: Ohta Hiroyuki , Tokumaru Katsumi 
Published: July 2006

Abstract
Diphenylmethyleneimino radicals, Ph2C=N·, generated from photolysis of benzophenoxime benzoates undergo aromatic substitution on benzene as well as dimerization into azine. On the other hand, phenylmethyleneimino radicals, PhCH=N·, generated from photolysis of benzaldoxime benzoate are oxidized to benzonitrile in preference to dimerization.
A Convenient Synthesis of 2,3-Benzotropone from α-Tetralone by Ring-expansion
Authors: Sato Masaru , Tanaka Takashi , Tsunetsugu Josuke , Ebine Seiji 
Published: July 2006

Abstract
2,3-Benzotropone (1) has conveniently been prepared from easily available α-tetralone (2) in good overall yield by the following successive reactions: dihalocarbene addition to enol-ether (3) derived from 2, ring-expansion of the adduct (4) to halobenzocycloheptadienone (5), and dehydrohalogenation of 5 giving 1.
Synthesis of Acyl Derivatives of β-Lysine for Peptide Synthesis
Authors: Wakamiya Tateaki , Uratani Hiroshi , Teshima Tadashi , Shiba Tetsuo 
Published: July 2006

Abstract
Dibenzyloxycarbonyl- and di-t-butyloxycarbonyl-l-β-lysine were synthesized from corresponding diacyl-l-ornithine by modified Arndt-Eistert reaction involving diazoketone preparation via the mixed carbonic carboxylic anhydride. These diacyl-β-lysine derivatives are required for total- or semi-syntheses of peptide antibiotics, tuberactinomycins or streptothricins.
Solvent Effect of Methanol on the Rate of Formation Reaction of Monochloroiron(III) Complex in Aqueous Solution
Authors: Wada Goro , Kobayashi Yaeko 
Published: July 2006

Abstract
The rate constants of the formation reaction of FeCl2+ complex from Fe(III) and Cl− ion were measured in water-methanol mixed solvents by use of a stopped-flow spectrophotometer. The apparent rate constant k is dependent upon the acid concentration of the medium, indicating that the reaction can proceed through two parallel paths, Fe3++Cl− (k1) and Fe(OH)2++Cl− (kH). Both k1 and kH increase with the increase in the mole fraction of methanol in the medium, xM. Since kH is much larger and is consequently much more accurately determined than k1 considerations were mainly made on the nature of kH. According to the dependence of kH on the dielectric constant of the medium, it was found that the activation free energy of the Fe(OH)2++Cl− reaction consists of the electrical and non-electrical parts and that the dimension of the activated complex corresponds approximately to the distance of the outer-sphere approach between the reacting species. These facts are therefore in favor of an outer-sphere mechanism in the anation reactions of iron (III) by simple anions.
Preparation and Some Properties of Triorganosiloxy Derivatives of Cyclopentadienyl Titanium
Authors: Suzuki Hideo , Takiguchi Toshio 
Published: July 2006

Abstract
Several triorganosiloxy derivatives of cyclopentadienyl titanium were synthesized by the reactions of dicyclopentadienyl titanium dichloride or cyclopentadienyltitanium trichloride with triorganosilanols or their sodium salts. The products obtained include π-Cp2TiClOSiMe3, π-CpTi(OSiMe3)3, π-CpTi(OSiMe2Ph)3, π-CpTi(OSiPh2Me)3, π-CpTi(OSiPh3)3, π-CpTi(OSiPh3)2Cl and π-CpTi(OSiPh3)Cl2. Some correlations were found to exist between the substituents on silicon atoms and cyclopentadienyl ring protons in NMR spectra and the Ti–O–Si bond absorptions in IR spectra. The chemical stabilities of the Ti–O–Si bonding in the products were dependent on the nature of the organic groups attached to the silicon atoms. The chemical resistance of the products against hydrolytic cleavage was regularly increased with successive replacement of methyl groups by phenyl groups.
The Carbonyliron Complexes of Some Chlorocarbons
Authors: Matsukura Takefumi , Mano Koichi , Fujino Akira 
Published: July 2006

Abstract
The (tetracarbonyl)iron complexes of perchloro-(3,4-dimethylenecyclobutene) and perchlorofulvene, and the (tricarbonyl)iron complex of the former chlorocarbon were synthesized. The structural evidences for those complexes were given on the basis of the DSC, their chemical behaviors, and the UV, IR and other spectral data. Particularly, their mass-, NQR- and 13C-NMR-spectra were discussed in detail by comparing them with those of the substrate chlorocarbons.
Optical Activity and Absolute Configuration of 2,3 :6,7-Dibenzobicyclo [3.3.1]nona-2,6-diene Derivatives
Authors: Tatemitsu Hitoshi , Ogura Fumio , Nakagawa Yasuhiro , Nakagawa Masazumi , Naemura Koichiro , Nakazaki Masao 
Published: July 2006

Abstract
2,3 : 6,7-Dibenzobicyclo[3.3.1]nona-2,6-diene-4,8-diol was synthesized and resolved via (−)-menthoxyacetate. Several kinds of optically active derivatives with the same absolute configuration were prepared from the (−)-diol and their chiroptical properties were recorded. The absolute configuration of this series of compounds was determined to be 1R, 5R by a chemical correlation with (R)-(−)-3-phenylbutanoic acid via (−)-1,3-diphenylglutaric acid and (−)-2,4-diphenylpentane.
Chemical Studies on Tuberactinomycin. IX. Nuclear Magnetic Resonance Studies on Tuberactinomycins and Tuberactinamine N
Authors: Wakamiya Tateaki , Shiba Tetsuo 
Published: July 2006

Abstract
Conformational analyses of peptide antibiotics tuberactinomycins were performed by NMR spectroscopy of 100 MHz. Studies on temperature dependence and deuterium exchange in amide proton resonances revealed the presence of an intramolecular hydrogen bond participated with α-amide proton of the guanidino amino acid residue in the cyclic part of each molecule. The same result was obtained in tuberactinamine N, which is the cyclopeptide moiety without amino acid side chain in tuberactinomycins N and O. The common rigid structure fixed by hydrogen bonding in the cyclic part seems to be a requisite for the exhibition of microbial activity in tuberactinomycin family.
Racemization Catalyst for Amino Acid. IV Enantiomer Differentiating Racemization with (S)-2′-Nitro-5-nitroso-6,6′-dimethylbiphenyl-2-ol
Authors: Hirota Kazuhiro 
Published: July 2006

Abstract
The racemizations of both enantiomers of alanine were carried out with (S)-2′-nitro-5-nitroso-6,6′-dimethylbiphenyl-2-ol (1) in the presence of cupric ion. In time course studies, the apparent half-life of d-alanine is longer than that of l-alanine. Such an enantiomer differentiating ability is explained by a mechanism involving a reactive product formed from the preferred conformation of the diastereomeric cupric complexes, consisting of 1 and d- or l-alanine, respectively. Synthesis of 1 via the resolution of 2′-nitro-6,6′-dimethylbiphenyl-2-amine is also presented.
Relative Determination of the Soret Coefficients of Electrolytes. V
Authors: Ikeda Toshio , Takatsuka Yoshihiro , Watanabe Takeshi 
Published: July 2006

Abstract
The Soret coefficients of aqueous solutions of some transition metal chlorides were determined by use of combined thermocells. The following values (in 10−3 K−1) were obtained in 0.005 M solutions at 25°C: −7.01 for MnCl2, −4.61 for CoCl2, −2.67 for NiCl2, and −3.43 for CuCl2. It was concluded that ion paramagnetism does not affect thermal diffusion.
Proton Magnetic Resonance in Some Triarylaminium Salt Free Radicals
Authors: Yoshioka Toshio , Watanabe Kohji , Ohya-Nishiguchi Hiroaki 
Published: July 2006

Abstract
The static magnetic susceptibilities from 77 to 300 K and the proton NMR spectra from 1.5 to 77 K have been measured on powder samples of tris-p-chlorophenylaminium perchlorate and chloroantimonate, and tris-p-tolylaminium perchlorate and chloroantimonate. The Weiss constants have been determined to be −2.0, −40, −0.5, and −10 K respectively. A broad maximum which indicates an antiferromagnetic interaction has been observed in the electron susceptibilities of the chloroantimonates obtained from the paramagnetic shift. The magnetic behavior is interpreted assuming the linear-chain model. On the other hand, the perchlorates obeyed the Curie-Weiss law down to 1.5 K. The isotropic hyperfine coupling constants of these four aminium salts have been estimated from the proton NMR spectra, from which the cations of these crystalline aminium salts can be expected to have similar configurations.
α,β-Unsaturated Carboxylic Acid Derivatives. IX. The Cyclization of α-(N-Acyl-hydroxyamino) Acid Esters with Ammonia or Hydroxylamine
Authors: Shin Chung-gi , Nanjo Katsumi , Kato Masaki , Yoshimura Juji 
Published: July 2006

Abstract
A new type of cyclization reaction of α-(N-acyl-hydroxyamino) acid esters to imidazolidine-4-one derivatives and the synthesis of several 2,5-piperazinedione derivatives are described. The treatment of β-methoxy-α-(N-chloroacetyl- or N-phthaloylglycyl-hydroxyamino) acid esters with ammonia gave 2-carbamoyl-2-(1-methoxy)alkyl-or aralkyl-imidazolidine-4-ones, while a similar cyclization of α-(N-haloacetylamino) or α-(N-haloacyl-hydroxyamino) acid esters with ammonia or hydroxylamine gave 2,5-piperazinedione, 1-hydroxy-2,5-piperazinedione or 1,4-dihydroxy-2,5-piperazinedione derivatives. The difference in the formation mechanisms between the imid-azolidine-4-one and 2,5-piperazinedione and their structural assignment were discussed.
Syntheses of Photosensitive Poly(amino acids)
Authors: Nanasawa Masato , Kamogawa Hiroyoshi 
Published: July 2006

Abstract
New poly(amino acids) (l-glutamic acid, l-tyrosine and l-lysine) containing photosensitive acryloyl, methacryloyl, and cinnamoyl groups in their side chains were synthesized from the corresponding amino acid NCAs. Their photosensitivities under UV irradiation were also investigated as to kind of functional group and the skeleton portion of the poly(amino acids). As regards the effect of the former, the sensitivities were in the order: acryloyl\simeqmethacryloyl&gt;cinnamoyl; as regards the effect of the latter, the sensitivities were in the order: poly-glutamate&gt;poly-lysine&gt;poly-tyrosine.
Restricted Rotation Involving the Tetrahedral Carbon. XVI. Isolation of Stable Rotamers about an sp3-sp3 Carbon Bond
Authors: Yamamoto Gaku , Nakamura Mikio , Oki Michinori 
Published: July 2006

Abstract
Both antiperiplanar and synclinal rotamers resulted from the restricted rotation about a C–C single bond between the bridgehead t-alkyl group and the skeleton of 9-(1,1-dimethyl-2-phenylethyl)-11-methoxycarbonyl-9,10-dihydro-9,10-ethenoanthracene-12-carboxylic acid are isolated. Optical resolution of the synclinal rotamer is successfully performed by way of the mono-(−)-menthyl esters and a pair of enantiomers of the acid, [α]D32±24.7°, are isolated as stable entities. Activation energy for the interconversion between the rotamers of dimethyl esters is found to be 33.2 kcal/mol with a frequency factor of 1013.3 s−1.
Measurement of Singlet-Triplet Absorption Spectrum of Pyridazine by a Sensitized-Phosphorescence Excitation Method
Authors: Yamamoto Kohzaburo , Takemura Takeshi , Baba Hiroaki 
Published: July 2006

Abstract
The S0→T absorption spectrum of pyridazine was measured by means of sensitized-phosphorescence excitation in EPA rigid-glass solution at 77 K. Its intensity was found to be much lower than that of the corresponding spectrum of pyrazine.
Note on the Preparation and Catalytic Properties of Dichlorotris[tris(p-methoxyphenyl)phosphine]ruthenium
Authors: Nishimura Shigeo , Yumoto Osamu , Tsuneda Kiyoshi , Mori Hiromu 
Published: July 2006

Abstract
The procedure for the preparation of RuCl2[(p-MeOC6H4)3P]3 was improved, resulting in a higher catalytic activity. The complex was thirteen and five times as active as RuCl2(Ph3P)3 in the hydrogenation of 1,4-androstadiene-3,17-dione (I) and 4-androstene-3,17-dione (II), respectively, indicating that the methoxy complex is more selective for formation of II in the consecutive hydrogenation pathway of I.
Smiles-Type Rearrangement of N-trans-Styrylsulfonyl) and N-(4-Phenyl-1,3-butadienylsulfonyl)thioureas and Isothioureas
Authors: Hasegawa Kiyoshi , Hirooka Syuzi , Sasaki Tadashi 
Published: July 2006

Abstract
Treatment of N-(trans-styrylsulfonyl)- (1) and N-(4-phenyl-1,3-butadienylsulfonyl)-N′-methylthiourea (2), and the corresponding S-methylisothioureas (6 and 7), with strong base afforded the Smiles-type and Michael-type products. Effects of substituents at C-2 and nucleophiles on the products are discussed.
Monolayers and Built-up Films of N,N′-Disubstituted Dithiooxamide Cu(II) Coordination Compounds
Authors: Suzuki Asahi , Ohkawa Kuwako , Kanda Seiichi , Emoto Masanori , Watari Shunichi 
Published: July 2006

Abstract
N,N′-Disubstituted dithiooxamide-Cu(II) as compound semiconductors prepared by the usual method have been liable to be an isomeric mixture of coordination polymers. Syntheses of the stereospecific coordination polymers were attempted by an interfacial technique. The dithiooxamides with two hydrophobic substituents, R’s, on nitrogen atoms of a ligand molecule could be spread on a water surface to form the monomolecular film, where its possible structure is cis isomers of the ligands. Some coordination compounds, i.e. the stereospecific coordination polymers, between the cis isomers and Cu2+ ions were found to be produced at the air-water interface by employing the substrate solution containing Cu2+ ions. This was established by the surface pressure vs. area measurements for their ligand molecules with C6H5CH2–, C6H11–, C12H25–, and C12H25OCOCH2– as hydrophobic substituents, and by the effects of various spreading solvents, pH in substrate solutions and temperatures on their monolayers. Furthermore, built-up films of these polymers were examined for thickness.
13C Nuclear Magnetic Resonance Studies of the Hindered Internal Rotation and the Molecular Association of N,N-Dimethylacetamide
Authors: Ando Isao , Jinno Naomi , Nishioka Atsuo 
Published: July 2006

Abstract
The concentration and temperature dependences of the 13C chemical shifts of N,N-dimethylacetamide (DMA) in CCl4, H2O, and H2SO4 solutions were measured by means of a 13C FT-NMR spectrometer at 25.15 MHz. From the temperature dependence of the chemical-shift difference between the cis- and trans-NCH3 carbons, the activation energy, Ea, for the hindered internal rotation about the C–N bond was obtained to be 10–17.5 kcal/mol; it was also found to be ca. 10 kcal/mol at an infinite dilution in a CCl4 solution. The chemical shift of each carbon in the DMA molecule was calculated using Pople’s expression under the average excitation-energy approximation by means of the CNDO/2 method. The calculated finding that each carbon in DMA appears in the order of carbonyl, trans-NCH3, cis-NCH3, and acetyl carbons from the low field agrees with the order assigned by McFarlane. Further, as for the molecular association in neat liquid, various models are discussed on the basis of quantum-chemical calculations, and a model is proposed which has antiparallel oriented carbonyl groups in associated states of the molecules of more than two. The observed differences between the chemical shifts of the carbonyl carbons at dilutions in CCl4 and H2O solutions, and between those in CCl4 and H2SO4 solutions, are found to agree well with the results calculated using the model in which the DMA molecules at dilutions in CCl4, H2O, and H2SO4 exist as monomer, hydrogen-bonded DMA with H2O, and protonated DMA respectively.
The Crystal and Molecular Structure of Versicolorin C, A Metabolite of Aspergillus versicolor
Authors: Fukuyama Keiichi , Tsukihara Tomitake , Katsube Yukiteru , Hamasaki Takashi , Hatsuda Yuichi 
Published: July 2006

Abstract
The crystal structure of versicolorin C, C18H12O7, has been determined by the X-ray diffraction method. The crystals are monoclinic, with the space group P21/a, and with four molecules in a unit cell with dimensions of a=24.918(7), b=7.922(3), c=7.003(3) Å, and β=92.85(4)°. The structure was refined by the least-squares method to R=0.053 for 1693 non-zero reflections. There are two intramolecular hydrogen bonds. A pair of molecules related by a center of symmetry forms a dimer by means of intermolecular hydrogen bonds.