bluuebunny/crossref_metadata_2025 huggingface dataset:
The Raman Spectra of Cobalt(III) Complexes. III. Differentiation between cis and trans Isomers of Tetraamminecobalt(III) Complexes
Authors: Kanamori Kan , Kawai Kiyoyasu
Published: July 2006

The Raman and the infrared spectra of tetraamminecobalt(III) complexes have been measured to find the vibrational criteria for differentiating between the cis and trans configurations. Conspicuous differences between the isomers were found in the ν(Co–NH3) region. Thus, generally the trans isomers have two bands at ca. 480 and ca. 450 cm−1 in the Raman spectra and one band at ca. 510 cm−1 in the infrared spectra, and the mutual exclusion rule virtually holds. On the other hand, the cis isomers have more than three bands in the region of both the Raman and the infrared spectra.
Solubility Diagrams of Cobalt(III) Complexes Containing Amino Acid. II. Spontaneous Resolution of Bis(ethylenediamine)glycinatocobalt(III) Salts
Authors: Kaki Satoshi , Yamanari Kazuaki , Shimura Yoichi
Published: July 2006

The binary and ternary solubility phase diagrams of the racemic and optically active complexes [Co(gly)(en)2]X2 were determined in water (X2=SO4, S2O3, (NO3)2, (SCN)2, (CH3CO2)2, (ClO4)2, (CH3CO2)ClO4, and [Sb2(d-tart)2]). Spontaneous resolution was found for the double salt of [Co(gly)(en)2](CH3CO2)ClO4 at 5–50 °C and for [Co(gly)(en)2]SO4 at 39–50 °C; the latter of these has been shown to crystallize as both a racemic compound (below 39 °C) and a conglomerate (above 39 °C).
Construction of an Adiabatic Calorimeter Workable under Constant High-pressure
Authors: Oguni Masaharu , Watanabe Kazuo , Matsuo Takasuke , Suga Hiroshi , Seki Syûzô
Published: July 2006

An adiabatic high-pressure calorimeter was constructed. The calorimeter cell was devised for minimization of the cell mass relative to the volume of the sample chamber. The pressure in the cell was controlled by joining the cell with a transmitting tube to a stabilized high-pressure system. The adiabatic conditions were achieved by temperature control of the transmitting tube as well as of adiabatic shields inside the cryostat. Procedures for the precise pressure control and for the determination of the molar volume and heat capacity with the correction for the mass transfer of pressure-transmitting liquid in a series of measurement were discussed. The apparatus is capable of measurement under constant pressure up to 110 MPa and over the temperature range from 100 to 370 K. The results on liquid 3-methylpentane which was used as the pressure medium proved satisfactory performance of this new-type calorimeter.
Optically Active Vanadium(IV) and (V) Complexes Containing (S)-N-[1-(2-Pyridyl)ethyl]iminodiacetate Ion
Authors: Okazaki Kenichi , Saito Kazuo
Published: July 2006

New optically active vanadium(IV) and (V) and mixed valence(IV,V) complexes containing a quadridentate ligand (S)-N-[1-(2-pyridyl)ethyl]iminodiacetate (S-peida2−) have been prepared: i.e. uninuclear distorted octahedral [VIVO(S-peida)(H2O)] and Li[Vv(O)2(S-peida)], a mixed valence binuclear Na[V2IV,VO3(S-peida)2], and an oxo-peroxo complex Na[VvO(O2(2−))(S-peida)]. The tertiary amino nitrogen of S-peida2− occupies the trans position to the oxo ligand in the first three complexes, but trans to the peroxo ligand in the last complex. Three absorption bands of [VIVO(S-peida)(H2O)] in the region from 10000 to 30000 cm−1 have been assigned to the d-d transitions, dxy→(dxz,dyz), dxy→dz2−y2, and dxy→dz2, in the order of increasing frequency. The mixed valence complex gives an intervalence transfer band and two d-d bands in the region from 9000 to 25000 cm−1. It gives a negative and a positive CD peak corresponding to the intervalence transition. The VV(O)2 and the VVO(O2) complex give a characteristic absorption shoulder at 25000 and a peak at 23500 cm−1 with corresponding weak negative CD peaks, respectively. They are assigned to charge transfer bands from oxo and peroxo to VV, respectively. The sign of CD peaks seems to be governed mostly by asymmetric arrangement of the ligating atoms and asymmetric deviation of ligating atoms from regular octahedron.
The Structure of Nickel(II) Bromide in Highly Concentrated Aqueous Solution by X-Ray Diffraction Analysis
Authors: Wakita Hisanobu , Ichihashi Mitsuyoshi , Mibuchi Takeharu , Masuda Isao
Published: July 2006

An X-ray diffraction analysis of the aqueous nickel(II) bromide solutions with the concentrations of 2.004, 4.064, and 4.845 mol dm−3 demonstrated the presence of the complex [NiBr(H2O)5]+. This inner-sphere type complex has interatomic distances of 2.52–2.58 Å for Ni–Br and of 2.04–2.05 Å for Ni–OH2. With an increase in the concentration the average number of the Ni–Br contacts per one Ni2+ ion increased; it was found to be 0.18, 0.47, and 0.68 in the 2.004, 4.064, and 4.845 mol dm−3 solutions, respectively.
A Novel Synthesis of 3-Aryl-1,2,4-benzotriazines via N-Phenylsulfonyl-N″-arylbenzamidrazones
Authors: Ito Suketaka , Tanaka Yumo , Kakehi Akikazu
Published: July 2006

3-Aryl-1,2,4-benzotriazines were obtained in good yields by the mercury(II) oxide-oxidation of N-phenylsulfonyl-N″-arylbenzamidrazones prepared from N-(phenylsulfonyl)benzohydrazonoyl chlorides and anilines. From the synthetic viewpoint for benzotriazines, this method may be of high utility on account of the availability of starting materials and higher yields.
Reactions of Aldonitrones with Phenylphosphonothioic Dichloride and Related Compounds. Formation of 2-Arylbenzothiazoles from α,N-Diarylnitrones
Authors: Yoshifuji Masaaki , Nagase Rihei , Kawashima Takayuki , Inamoto Naoki
Published: July 2006

Reactions of α-aryl-N-methylnitrones with phenylphosphonothioic dichloride (1), diphenylphosphinothioic chloride (6), or thiophosphoryl trichloride (7) gave N-methylbenzamide and N-methylthiobenzamide derivatives, and the latter became major in the presence of tertiary amine. α,N-Diarylnitrones (4) reacted with 1 to give 2-arylbenzothiazoles (5) at room temperature in moderate yields. Reaction of 4 with 6 (at room temperature) or 7 (in refluxing THF) gave 5 in a low yield, whereas a similar reaction of 4 with 7 at 0 °C afforded N-benzylidene-2-chloroaniline in a high yield. A mechanism for the formation of 5 has been discussed briefly.
Photochemical Reaction of Ethyl 3-Oxo-2,4-diphenylbutanoate
Authors: Yoshioka Michikazu , Osawa Haruhiko , Fukuzawa Shinji
Published: July 2006

Irradiation of ethyl 3-oxo-2,4-diphenylbutanoate in hexane gave the products formed by recombination of the radicals (Ph–\dotCH2 and/or Ph–\dotCH–CO2Et) resulting from decarbonylation, together with small amounts of 1,2-diphenylethanol and ethyl α-hydroxyphenylacetate, whereas in benzene no 1,2-diphenylethanol was found. Under oxygen an increased amount of ethyl α-hydroxyphenylacetate and no radical recombination products were observed.
Palladium-catalyzed New Carbon-Phosphorus Bond Formation
Authors: Hirao Toshikazu , Masunaga Toshio , Yamada Naoto , Ohshiro Yoshiki , Agawa Toshio
Published: July 2006

Dialkyl arylphosphonates are prepared by the palladium-catalyzed reaction of aryl bromides with dialkyl phosphite in the presence of triethylamine. The similar treatment of vinyl bromides gives dialkyl vinylphosphonates stereoselectively.
Branched-chain Sugars. XXIX. Synthesis of Moenuronic Acid (4-C-Methyl-d-glucuronic Acid)
Authors: Sato Ken-ichi , Kubo Kazusuke , Hong Namgi , Kodama Hisashi , Yoshimura Juji
Published: July 2006

Moenuronic acid (4-C-methyl-d-glucuronic acid), a branched-chain sugar component of moenomycin A, was synthesized by the introduction of an axial C-methyl group into methyl 2,3-di-O-benzyl-6-O-trityl-α-d-xylo-hexopyranosid-4-ulose by the reaction with methyllithium, followed by deprotection and platinum-catalyzed oxidation of the C-6 position. Stereoselectivities in a few reactions for the introduction of C-methyl group were examined.
The Crystal Structure of o-Phenylenediamine Dihydroiodide
Authors: Kozawa Kozo , Uchida Tokiko
Published: July 2006

Crystals of o-phenylenediamine dihydroiodide are orthorhombic; a=7.828(1), b=13.158(1), c=5.043(1) Å, Z=2, and space group Pmnm. The structure was solved by the heavy-atom method and refined with 1359 diffractometer data points to the final R=0.052. It is isostructural with o-phenylenediamine dihydrobromide. Protonated amino groups link to iodide ions by hydrogen bonds.
Crystal and Molecular Structure of trans-2,5-Dimethylpiperazine
Authors: Okamoto Kojun , Sekido Kiyotane , Ono Haruaki , Noguchi Teruo , Hirokawa Sakutaro
Published: July 2006

The crystal structure of trans-2,5-dimethylpiperazine has been determined by means of the X-ray method. The molecule is centrosymmetric, the piperazine ring having a chair form. The methyl groups are in the equatorial position. The molecules are linked together by N–H···N hydrogen bonds (N···N=3.305(3) Å) to form infinite ribbons along [011].
Vibrational Spectra and Normal Coordinate Calculations for Trimethylstannane
Authors: Imai Yoshika , Aida Koyo
Published: July 2006

The infrared and Raman spectra of trimethylstannane and its deuterated analogues were obtained. Assignments for all the fundamentals except internal torsions were made and normal coordinate calculations were carried out to confirm the proposed assignments.
Selective Adsorption of Alkylbenzenesulfonates on Quaternized Crosslinked Poly(4-vinylpyridine)
Authors: Kawabata Nariyoshi , Natsuhara Eisuke , Higuchi Ichiro , Yoshida Jun-ichi
Published: July 2006

Selective ion-exchange adsorption of a series of alkylbenzenesulfonate ions (CnBS−) on a series of crosslinked poly(N-alkyl-4-vinylpyridinium bromide) (CmVP) and crosslinked poly(N-benzyl-4-vinylpyridinium bromide) (BVP) was investigated based upon the selectivity coefficient of the resins for CnBS− relative to Br− which was expressed as KBr−CnBS−. In the adsorption of CnBS− of n<8, the selectivity coefficient linearly increased with the number of carbon atoms of the alkyl chain, n, of CnBS−, which was ascribed to the hydrophobic interaction between the alkyl chain of CnBS− and the resin. In the adsorption of CnBS− of n>8, however, the selectivity coefficient did not increase with n, which was explained in terms of a steric effect. The selectivity coefficient also increased with the number of carbon atoms of the alkyl chain, m, of CmVP, but saturation was also observed for the adsorption on CmVP of m>12. In the adsorption of CnBS− of n<8 on BVP, significant influence of the degree of quaternization was not observed. In the adsorption of C12BS−, however, BVP of lower degree of quaternization showed a much larger selectivity than that of BVP of higher degree of quaternization. The observation indicated that steric repulsion between CnBS− ions adsorbed on the surface of the resin played a crucial role.
Vibration-rotation Spectra of Formamides
Authors: Sugawara Yoko , Hamada Yoshiaki , Tsuboi Masamichi
Published: July 2006

Taking advantage of the Fourier transform infrared (FTIR) spectrophotometry in accumulating a very weak available radiation, which comes out from a multiple-reflection-type gas-cell (17 m), we have been able to record the infrared absorption spectrum of formamide (HCONH2 or DCONH2) at room temperature, where its vapor pressure is only 0.1 Torr (1 Torr≈133.322 Pa) in the order of magnitude. From an analysis of the rotational structure (resolution 0.5 cm−1) of the C–H stretching band, a revised set of parameters has been obtained. A Q-branch analysis was made for the v=2←0 and v=3←1 bands (resolution 0.24 cm−1) of the amino wagging vibration, where v is its vibrational quantum number. The rotational constants A−B were determined to be 2.0269 cm−1 for the v=2 state and 1.9990 cm−1 for the v=3 state, and the transition frequencies 657.75 cm−1 for v=2←0 and 769.85 cm−1 for v=3←1. On the basis of these new parameter values, a discussion was made of the amino wagging coordinate of this molecule.
Extractive Spectrophotometric Determination of Antimony(III), Bismuth, Indium, and Gallium with Pyrocatechol Violet and Tridodecylethylammonium Bromide
Authors: Shijo Yoshio , Shimizu Tokuo , Sakai Kaoru
Published: July 2006

The spectrophotometric method for the determination of trace amounts of antimony(III), bismuth, indium, and gallium based on the solvent extraction of the ion associate formed between anionic metal–Pyrocatechol Violet complexes and tridodecylethylammonium bromide is proposed. The maximum absorbance of the extracted species occur at 530, 564, 600, and 595 nm for antimony(III), bismuth, indium, and gallium. The molar absorptivities for antimony(III), bismuth, indium, and gallium are 3.32×104, 3.31×104, 8.20×104, and 8.00×104 dm3 mol−1 cm−1. The optimum pH ranges for the extraction of antimony(III), bismuth, indium, and gallium are from 3.7 to 4.8, from 5.8 to 6.7, from 5.3 to 5.4, and from 5.5 to 6.2 respectively. The composition of the extracted complexes (metal:PV:TDEA) are estimated to be 1:2:3 for antimony(III) and 1:2:2 for the other metals. The interference of foreign ions is described.
Cobalt(III) Complexes with Quadridentate Ligands. III. The Preparation and Properties of the Salicylato or Dichloro(quadridentate amine)cobalt(III) Complexes
Authors: Yamamoto Yoshihisa , Kudo Hiroko , Toyota Eiko
Published: July 2006

In the 1H and 13C NMR spectra of trans- or cis-dichloro(quadridentate amine)cobalt(III) chloride hydrates, [CoCl2L]Cl·nH2O (L: 2,2,2-tet(trien) (1a), 2,3,2-tet (1b), 3,2,3-tet (1c), and 3,3,3-tet (1d)), the signals of their methylene protons and methylene carbons have been assigned to the individual methylene protons and methylene carbon of the coordinated quadridentate amine ligands. The order of 1H and 13C chemical shift of their methylene protons and methylene carbon is as follows:

(Remark: Graphics omitted.)

Thus, the signal of the center methylene protons (or carbon) of the coordinated quadridentate amine ligands appears at higher field than that of the NH-side methylene protons (or carbon). cis-β1-Salicylato(3,7-diazanonane-1,9-diamine)cobalt(III) chloride hydrate, cis-β1-[Co(sal)(2,3,2-tet)]Cl·H2O (3b), and cis-β2-salicylato(quadridentate amine)cobalt(III) chloride hydrates, cis-β2-[Co(sal)L]Cl·nH2O (L: 2,3,2-tet (4b), 3,2,3-tet (4c) and 3,3,3-tet (4d)) have been isolated from a reaction mixture of sodium salicylate or salicylic acid and 1b–d. The properties of 3b and 4b are similar to those of the previously reported complexes 3a (L: 2,2,2-tet, β1-form) and 4a (L: 2,2,2-tet, β2-form), respectively. Those of 4c are similar to those of 4d. Complex 4d is the most unstable complex among 4a–d. This property is attributable to the center methylenes of the coordinated quadridentate amine ligands.
Preparation and 119Sn NMR Spectra of Coordination Compounds of Di-t-butyltin(IV) Derivatives
Authors: Otera Junzo , Yano Torn , Kusakabe Kazunori
Published: July 2006

Di-t-butyltin bis(chelates) were prepared and characterized in comparison with dimethyltin analogs. 119Sn NMR spectra show a six-coordinate configuration for the acetylacetonate, tropolonate, and oxinate; a nonchelating structure is partially involved in the 2-methyloxinate and dialkyldithiocarbamates. Di-t-butyltin dichloride gives no isolable adducts with monodentate ligands; however, the Job’s continuous variation method using 119Sn NMR spectra has revealed that complexations with 2 : 1 and/or 1 : 1 donor/Sn molar ratios occur in ether. It has been concluded that t-butyl group reduces the acceptor property of tin by means of both inductive and steric effects.
Preparation and Circular Dichroism Spectra of trans-Dichlorocobalt(III) Complexes with (2-Aminoethyl)diphenylphosphine and Related Ligands. Crystal Structures of trans(Cl,Cl), cis(P,P)-[CoCl2{NH2CH2CH2P(C6H5)2}2]·1/2[CoCl4] and -[CoCl2{NH2CH2CH2P(C4H9)(C6H5)}2]ClO4
Authors: Kinoshita Isamu , Yokota Yasuno , Matsumoto Keiji , Ooi Shun’ichiro , Kashiwabara Kazuo , Fujita Junnosuke
Published: July 2006

Green trans-dichlorocobalt(III) complexes with a variety of achiral and chiral (2-aminoalkyl)phosphines have been prepared and characterized. The crystal structures of [CoCl2{(2-aminoethyl)diphenylphosphine}2]1/2[CoCl4] and [CoCl2{(R)-(2-aminoethyl)butylphenylphosphine}2]ClO4 have been determined by X-ray analyses. Both complex cations have a distorted octahedral coordination with two Cl atoms in the trans positions and two P (and N) atoms in the cis positions. The Co–N distances (2.02–2.05 Å) are 0.05–0.07 Å longer than the usual Co(III)–N distance, and the P–Co–P angles are widened (99.4 and 103.1°) on account of bulky substituents on the phosphorus atoms. The circular dichroism spectra of [CoCl2{(2-aminoethyl)diphenylphosphine}2]ClO4 (space group P3221) in Nujol mull and the complexes with chiral (aminoalkyl)phosphines in methanol solutions have been recorded and compared with those of related complexes.
Magnetic Properties of [μ-(Ethylenediaminetetraacetato)-di-μ-sulfido-bis{oxomolybdate(V)}]2− and [μ-(Ethylenediaminetetraacetato)-di-μ-oxo-bis{oxomolybdate(V)}]2− Ions
Authors: Kobayashi Hanako , Tsujikawa Ikuji , Shibahara Takashi , Uryû Norikiyo
Published: July 2006

Sodium [μ-(ethylenediaminetetraacetato)-di-μ-sulfido-bis{oxomolybdate(V)}]·n-hydrates, n=2 and 3, are antiferromagnetic dimers with an exchange interaction within a pair of Mo(V) ions of about −140 k having an averaged g-value of about 2 for each Mo(V) ion. In these salts, magnetic moments of only about 0.5 Bohr magneton are localized at Mo(V) sites, though Mo(V) has one electron in the 4d orbital. Here a π-bonding looped structure is considered to have a contribution to the diamagnetic susceptibilities of about −5.0×10−5 (CGSemu). Sodium [μ-(ethylenediaminetetraacetato)-di-μ-oxo-bis{oxomolybdate(V)}]·n-hydrates, n=3, 4, and 6, are the antiferromagnetic dimers with an exchange interaction within a pair of Mo(V) ions of about −150 k and an averaged g-value of 1.91. The magnetic moments of only about 0.5 Bohr magneton are localized at Mo(V) sites. In these salts, too, a π-bonding structure in each dimer is considered to make a contribution to the diamagnetic susceptibility of about −4.0×10−5 (CGSemu). A broad minimum of the molar magnetic susceptibility of [μ-(ethylenediaminetetraacetato)-di-μ-oxo-bis{oxomolybdate(V)}] salts was considered due to the conformation interconversion.
The Use of Grignard Reagents in Carbohydrate Synthesis. The Synthesis of Branched-chain Deoxy Sugars and Their Anomerizations
Authors: Kawana Masajiro , Koresawa Tetsuo , Kuzuhara Hiroyoshi
Published: July 2006

The reactions of methyl 5-O-benzyl-2-O- and -3-O-tosyl-β-d-ribofuranosides with methylmagnesium iodide gave, in one-step, 2-deoxy-3-C- and 3-deoxy-2-C-methyl branched-chain sugars, respectively. These sugars were anomerized with Grignard reagents; the thermodynamically more stable anomers were converted preferentially into the respective less stable anomers.
The Synthesis and Studies of Several [2.2.2]Ferrocenophane Derivatives
Authors: Kasahara Akira , Izumi Taeko , Shimizu Iwao , Oikawa Tadashi , Umezawa Hiroshi , Hoshino Isao
Published: July 2006

Several ferrocenophanes, in which the two cyclopentadienyl rings are linked by acetylenic and olefinic bonds and aromatic rings, have been synthesized via the titanium-induced reductive coupling of the corresponding formyl compounds. The structures of these ferrocenophane compounds were determined by means of their IR and NMR spectra. The transannular π-electronic interactions between the two chromophores were examined on the basis of the electronic spectra.
Synthetic Studies on the Validamycins. IV. Synthesis of Dl-Valienamine and Related Branched-chain Unsaturated Aminocyclitols
Authors: Toyokuni Tatsushi , Ogawa Seiichiro , Suami Tetsuo
Published: July 2006

The first synthesis has been achieved of the racemates of valienamine and its related, branched-chain unsaturated aminocyclitols. Two synthetic routes for valienamine were developed, one of which is stereoselective and highly efficient. The key transformation is a stereospecific SN2′ attack (apofacial) by an azide ion on the allyl chloride, prepared by regioselective epoxidation of the conjugated diene followed by treatment with hydrochloric acid. Some information is described which is furnished from 13C NMR spectra for the new branched-chain unsaturated aminocyclitols and cyclitols.
The Cycloaddition of N,N-Diethyl-1,3-butadienylamine with Some Diarylnitrilimines
Authors: Oida Tatsuo , Tanimoto Shigeo , Ikehira Hideyuki , Okano Masaya
Published: July 2006

The cycloaddition of N,N-diethyl-1,3-butadienylamine with some diarylnitrilimines was investigated. 1,3-diaryl-4-vinylpyrazoles, (1,3-diaryl-2-pyrazolin-5-yl)acetaldehydes, 1,3-diaryl-4-(1,3-diaryl-2-pyrazolin-5-yl)pyrazoles, and 1,3-diarylpyrazoles were obtained.
Cyclic Peptides. XV. Synthesis of [4-α-Hydroxyalanine]AM-toxin II
Authors: Noda Kosaku , Nakashima Junko , Lee Sannamu , Izumiya Nobuo
Published: July 2006

An AM-toxin II analog, cyclo(–l-Ala1–l-Hmb2–l-App3–Hyala4–), with an α-hydroxyalanine (Hyala) residue in place of dehydroalanine in position 4 was synthesized from pyruvoyl–l-Ala–l-Hmb–l-App–amide (Hmb, 2-hydroxy-3-methylbutanoic acid; App, 2-amino-5-phenylpentanoic acid) by intramolecular condensation between the pyruvoyl and carbamoyl groups. The synthetic peptide did not show the toxic activity of AM-toxin II.
Study of Ion Transport across Amphoteric Ion Exchange Membrane. II. Transport of Symmetric Tetraalkylammonium Chlorides
Authors: Kaibara Kozue , Sonoda Hideaki , Nagata Yoshihiko , Kimizuka Hideo
Published: July 2006

Transport characteristics of NH4Cl, (CH3)4NCl (TMA–Cl), (C2H5)4NCl (TEA–Cl), (n-C3H7)4NCl (TPA–Cl), and (n-C4H9)4NCl (TBA–Cl) across homogeneous type amphoteric ion exchange membrane (1.0-PA-29, Kanegafuchi Chem. Ind.) were studied. Membrane potentials and conductances of the concentration cell systems were measured to calculate the membrane permeabilities which represent a measure of ionic permselectivity. Membrane potential changed considerably with cationic species and the membrane tended to behave more anionic selectively with increasing bulkiness of cations. The cationic permeabilities calculated from electrochemical data were PNH4>PTMA>PTEA>PTPA>PTBA. Membrane permeabilities to chloride ions, PCl, were greater than those to cations in all the systems studied and it was interesting that PCl values and their dependencies on external electrolyte concentration were almost unchanged irrespective of the difference in cationic species. The present experiment was designed in order to examine the effects of ionic size on the transport processes across homogeneous type amphoteric ion exchange membrane. The obtained results indicated that the hydrated radius of permeant ion is an important factor to control the ionic transport processes and to reveal the potentiometric selectivity in these systems. It was suggested that the ion transport across homogeneous type amphoteric ion exchange membrane is strongly affected by hydrodynamic properties of permeant ion, but scarcely influenced by ionic charges of which effects are well known to be exclusive in the uniform cation and anion exchange membranes.
The Precipitation of Human Fibrinogen by Zinc Chloride
Authors: Maeda Hiroshi , Kishi Takaaki , Ikeda Shoichi
Published: July 2006

The precipitation of human fibrinogen by ZnCl2 was studied by measuring the turbidity and the protein concentration in the supernatant (referred as solubility). Different kinetic patterns, either fast or slow, were observed in both solubility and turbidity depending on whether ZnCl2 concentration (CM) was larger or smaller than the critical concentration. In the slow pattern, the increase of the turbidity and the decrease of the solubility both occurred slowly and almost linearly with time. In the fast pattern, these changes occurred rapidly and stationary values were reached within 30 min for the turbidity and 2 h for the solubility. These two stationary values were found to be linearly related to each other. The stationary solubility decreased as CM increased, while it increased with the total amount of the protein. The dissolution of the precipitates was very slow resulting in a practically irreversible precipitation. A gelation model was proposed to account for these characteristic features, according to which fibrinogen molecules were linked to each other through the ’bond’ mediated by a zinc atom.
Stereochemical Investigation on Asymmetrically Modified Raney Nickel Catalyst. Mode of Interaction between Modifying Reagent and Substrate in the Enantioface-differentiating Process
Authors: Tai Akira , Harada Tadao , Hiraki Yuji , Murakami Sigeki
Published: July 2006

The mode of enantioface-differentiating hydrogenation with asymmetrically modified Raney nickel (MRNi) was investigated by using various sorts of modifying reagents and substrates. The optical yields (O.Y.) of the hydrogenation of methyl acetoacetate over MRNi for different modifying reagents occured in the following order: (Remark: Graphics omitted.), (Remark: Graphics omitted.). The hydrogenation of various substrates of the structure, (Remark: Graphics omitted.), over tartaric acid-modified Raney nickel (TA–MRNi), gave high optical yields only when the substituent –Y functioned as a good hydrogen bond acceptor like a carbonyl group, and two pairs of hydrogen bondings between substrate and two hydroxyl groups of tartaric acid were available. As for the stereochemistry of the reaction in such a case, (R,R)-TA–MRNi always gave (R)-product in excess. Based on the stereochemistry of the reaction and the role of hydrogen bonds between modifying reagent and substrate, a stereochemical model is proposed to elucidate the mode of enantioface-differentiating hydrogenation of prochiral ketones over TA–MRNi.
Aryl Rearrangement on the Photolysis of 2-Aryl-2-ethoxy-2-phenylethyl Cobaloxime
Authors: Tada Masaru , Inoue Kunimi , Okabe Masami
Published: July 2006

The photolysis of 2-aryl-2-ethoxy-2-phenylethyl cobaloxime followed by hydrolysis gave two kinds of substituted 1,2-diphenylethanones arising via phenyl or substituted-phenyl migration. The substituent effect on the aryl rearrangement is similar to that on the reported neophyl rearrangement, and the rearrangement takes place by a radical mechanism without the deep involvement of cobaloxime(II).
Syntheses of Polyoxathia[n]ferrocenophanes and Its Extraction Ability with Metal Cations
Authors: Akabori Sadatoshi , Habata Yoichi , Sato Masaru , Ebine Seiji
Published: July 2006

Mononuclear polyoxathia[n]ferrocenophanes (8a–d) and binuclear polyoxadithia[n,n]ferrocenophanes were synthesized by the reaction of 1,1′-bis(ω-chloropolyethyleneoxy)ferrocene with sodium sulfide in N,N-dimethylformamide and the complexing ability of 8a–d with alkali and transition metal cations was measured by an extraction method. Compound 8d extracts a thallium ion specifically, the extraction efficiency of several ions being in the order: Tl+>>Rb+>K+>Cs+>Na+>Li+.
The Synthesis of Tetrakisdehydrotetraazaannulenes. Tetramethyl[36]-, -[48]annulene, and Their Benzoannelated Derivatives
Authors: Ojima J\={u}ro , Kirita Mitsuru , Murosawa Yoshiko , Nakada Tetsuya
Published: July 2006

The conjugated mono-, di-, tri-, and tetraene, containing a terminal acetylene group were converted into a variety of symmetrical and unsymmetrical conjugated azines on treatment with aqueous hydrazine in ethanol. Oxidative couplings of these azines were attempted using anhydrous copper(II) acetate in pyridine and ether. Each of unsymmetrical azines, 3,16-dimethyl-8,9-diaza-3,5,7,9,11,13,15-octadecaheptaene-1,17-diyne and 1,10-bis(o-ethynylphenyl)-4,5-diaza-1,3,5,7,9-decapentaene, gave the corresponding two isomeric cyclic dimers: The former gave 7,12,25,30-tetramethyl-8,10,26,28-tetrakisdehydro-1,2,17,18-tetraaza[36]annulene and 7,12,25,30-tetramethyl-8,10,26,28-tetrakisdehydro-1,2,19,20-tetraaza[36]annulene, and the latter gave 6,7:12,13:24,25:30,31-tetrabenzo-8,10,26,28-tetrakisdehydro-1,2,17,18-tetraaza[36]annulene and 6,7:12,13:24,25:30,31-tetrabenzo-8,10,26,28-tetrakisdehydro-1,2,19,20-tetraaza[36]annulene, although only in poor yields. Coupling of symmetrical azines, 3,22-dimethyl-12,13-diaza-3,5,7,9,11,13,15,17,19,21-tetraeicosadecaene-1,23-diyne and 1,16-bis(o-ethynylphenyl)-8,9-diaza-1,3,5,7,9,11,13,15-hexadecaoctaene, furnished cyclic dimers, 11,16,35,40-tetramethyl-12,14,36,38-tetrakisdehydro-1,2,25,26-tetraaza[48]annulene and 10,11:16,17:34,35:40,41-tetrabenzo-12,14,36,38-tetrakisdehydro-1,2,25,26-tetraaza[48]annulene, respectively, in moderate yields. Examination of 1H NMR spectra indicates that these tetraazaannulenes are atropic.
Base-induced Oxygenation and Chemiluminescence of 10-Methylacridinium and 1-Methylquinolinium Salts in Dimethyl Sulfoxide
Authors: Suzuki Nobutaka , Kazui Yoshihiko , Tsukamoto Toshio , Kato Masahiro , Izawa Yasuji
Published: July 2006

10-Methylacridinium methyl sulfate and the 1-methylquinolinium salt gave strong light emission, when oxidized with ground state oxygen in the presence of t-BuOK in DMSO, owing to the fluorescence of 10-methyl-9(10H)-acridinone and 1-methyl-1(4H)-quinolinone excited to their S1 state.
The X-Ray Structure of 2-Aminocyclohexanone Oxime Hydrochloride
Authors: Kitano Yukishige , Matsukuma Yoshihisa , Imamura Shinzo , Takagi Ryo , Ashida Tamaichi
Published: July 2006

The crystal structure of the title compound was determined by the X-ray method. The space group is P\bar1, with a=8.537(1), b=5.223(3), c=9.505(1) Å, α=91.04(2), β=80.58(1), γ=99.16(3)°, and Z=2. The hydroxyl group of the oxime takes the anti conformation to the amino group in the solid state. The molecules, linked together by NH···Cl and OH···Cl hydrogen bridges, form columns in the crystal.
Contribution of Quadruply Degenerate π-Electron Orbitals to London Susceptibility
Authors: Horikawa Tsuyoshi , Aihara Jun-ichi
Published: July 2006

A graph-theoretical formula was derived to evaluate the contribution of quadruply degenerate π-electron orbitals to London diamagnetism. This formula enables us to calculate London susceptibilities of such compounds as p-terphenyl and perylene without factorization of their secular determinants.
Catalytic Hydrogenolysis of 1,1-Difluoro-2-phenyl- and 1,1-Difluoro-3-methyl-2-phenylcyclopropane
Authors: Isogai Koji , Nishizawa Naomi , Saito Tetsuji , Sakai Jun-ichi
Published: July 2006

The title compounds were hydrogenolyzd over PdO or Raney nickel. The C2–C3 bond of the cyclopropane ring underwent cleavage exclusively over the both catalysts. The contribution of the fluorine substituent to the lengthening and weakening the C2–C3 bond of the cyclopropane ring seems to become a dominant factor in the regioselectivity.
Studies on Salt Hydrate for Latent Heat Storage. III. Pseudo-binary System, CH3CO2Na·3H2O–HCONH2
Authors: Wada Takahiro , Kimura Fumiko , Yamamoto Ryoichi
Published: July 2006

A pseudo-binary system CH3CO2Na·3H2O–HCONH2 has been studied by differential scanning calorimetry. In this system, a one to one addition compound CH3CO2Na·HCONH2·3H2O is formed. This addition compound melts congruently at 40.5 °C and its heat of fusion is 255 J/g. So, it is hopeful for solar energy storage.
Dispersibility of Magnetic and Nonmagnetic Iron(III) Oxides in 2-Butanone
Authors: Kandori Kazuhiko , Kitahara Ayao , Kon-no Kijiro
Published: July 2006

The dispersion stability of needlelike and octahedral iron(III) oxides of magnetic or nonmagnetic particles in 2-butanone was studied. Two kinds of copolymers of poly(vinyl acetate-vinyl chloride-maleic acid) (VAVCCOOH) and poly(vinyl acetate-vinyl chloride-vinyl alcohol) (VAVCOH) were used as dispersants. The sedimentation of dispersions, the adsorption of copolymer dispersants on the particles and zeta potentials were measured. By polymer adsorption, the dispersion of nonmagnetic needlelike iron(III) oxide was stabilized and the dispersions of magnetic needlelike iron(III) oxides were somewhat stabilized, but the dispersions of magnetic octahedral iron(III) oxides were only slightly stabilized. This characteristic behavior of the sedimentation experiment was discussed in relation to the amount of polymer adsorption and zeta potential and was correlated with the observations by an electron microscope. The magnetic attractive force operating between the two magnetic particles was calculated to illustrate the dispersibility of magnetic oxides. It was suggested from the calculation that the strength of the magnetization and the volume of a particle are the main factors affecting the flocculation of the magnetic particles.
Association of Chlorophyll with Amides on Plasticized Polyethylene Particles. II. The Isomeric N-Pyridylmyristamides
Authors: Kusumoto Yoshihumi , Seely Gilbert R , Senthilathipan Velu
Published: July 2006

When chlorophyll, together with certain other amphiphilic substances, is adsorbed to particles of polyethylene plasticized by incorporation of tetradecane, it is maintained in monomeric or oligomeric forms with characteristic absorption and fluorescence spectra. The present work describes the properties of chlorophyll a on such particles in the presence of the three isomeric N-pyridylmyristamides, and of the similarly shaped but not basic compound myristanilide, in an effort to ascertain the structural factors governing associations of these species. Absorption and fluorescence spectra at room temperature are resolved into minimal sets of Gaussian components, and relations between the component sets are proposed. The positions of the component bands and their relative abundance are characteristic of the amide used. The 3- and 4-pyridyl isomers bind more strongly to chlorophyll, probably by ligation of the pyridine nitrogen to Mg of the pigment. The 2-pyridyl isomer and myristanilide bind more weakly, probably through the amide carbonyl group. The association of chlorophyll into species with characteristic absorption and fluorescence bands is promoted more strongly by the 3- and 4-isomers than by the 2-isomer and myristanilide, and probably involves hydrogen bonding to chlorophyll carbonyl groups. A possible manner of association of chlorophyll in the presence of N,N-dimethylmyristamide is also presented. By way of comparison, chlorophyll adsorbed with N-dodecylpyridinium bromide, which lacks a nucleophilic function, is mainly in the microcrystalline hydrate form absorbing near 740 nm.
Gravimetric Determination of Copper(II) Using N1-Hydroxy-N1-(m-tolyl)-N2-(o-chlorophenyl)-p-toluamidine Hydrochloride
Authors: Mohabey Hemlata , Sharma Pramod Kumar , Mishra Rajendra Kumar
Published: July 2006

A simple, rapid, and accurate method has been developed for the gravimetric determination of Copper(II) using a new reagent N1-hydroxy-N1-(m-tolyl)-N2-(o-chlorophenyl)-p-toluamidine hydrochloride (HTCPTH). The proposed reagent reacts quantitatively with copper at 3.3–11.0 pH giving a buff coloured precipitate. The precipitated complex can be easily filtered, dried and directly weighed as (C21H18N2OCl)2Cu. The complex is thermally stable as is evident from DTA and TGA studies up to 210 °C and insoluble in many organic solvents. Most of the common ions including Ni(II), Co(II), Cr(III), Mn(II), etc. do not interfere. The interference due to iron(III) can be eliminated by masking it with tartaric acid. The method has been successfully applied for the determination of copper in some British Chemical Standards alloys.
Thermal Properties of Solid Bis(2,3-alkanedione dioximato)nickel(II). Crystal Structure Transformation
Authors: I Mikiya , Wakita Hisanobu , Masuda Isao
Published: July 2006

The thermal behavior in the solid state of the title complexes was investigated. Here 2,3-alkanedione dioximato is CH3–C(=NOH)–C(=NO)–R; R includes C2H5 (1), n-C3H7 (2), n-C4H9 (3), n-C5H11 (4), n-C6H13 (5), and n-C8H17 (6) groups. The complexes, 1, 2, 5, and 6, underwent thermal crystal structure transformation; the transformation was irreversible for 1 and 5, and reversible for 2 and 6. The ΔHt values, heats of transformation, were found to fall in the 5.3–32.6 kJ mol−1 range. The ΔHm values, heats of melting, were determined for the complexes, 2–6. On the basis of these data, the thermal characteristics for these complex crystals are discussed in relation to the nature of the R groups.
Studies of Bitter Peptides from Casein Hydrolyzate. III. Bitter Taste of Synthetic Analogs of BPIa (Arg–Gly–Pro–Pro–Phe–Ile–Val) Containing d-Proline or Glycine in Place of l-Proline
Authors: Miyake Ichizo , Kouge Katsushige , Kanehisa Hidenori , Okai Hideo
Published: July 2006

In order to elucidate the relationship between chemical structure and bitter taste of BPIa, the analogs containing d-proline or glycine in place of the l-proline in the 3- or 4-positions were synthesized. The bitter taste of [d-Pro3,4]–BPIa (ld-d), [d-Pro3]–des–Pro3–BPIa (2d), and [Gly3]–des–Pro3–BPIa lacking the l-proline residue was much weaker than that of the peptides containing the l-proline, BPIa (1l-l), 1l-d, 1d-l, and 2l. The CD curves of these analogs and BPIa were measured in water. The results suggested that the bitter taste of BPIa is caused by the spatial structure attributed to the l-proline residue.
Reaction of Secondary Aromatic Amines with Manganese(III) Acetate
Authors: Nishino Hiroshi , Kurosawa Kazu
Published: July 2006

The reaction of 2-(methylamino)benzophenone with manganese(III) acetate afforded 5-[(o-benzoylanilino)methyl]-2-(methylamino)benzophenone, 2-aminobenzophenone, 5-formyl-2-(methylamino)benzophenone, 2-amino-5-[(o-benzoylanilino)methyl]benzophenone, 2-formamidobenzophenone, 2-amino-5-formylbenzophenone, and 2-(N-methylformamido)benzophenone. It was found that the reaction did not cause oxidative cyclization, but dimerization and conversion of N-methyl into N-formyl groups. Characterization of the products, the detailed oxidation mechanism, and the effects of the additives are discussed.
Reactions of 2-Methylenebenzothiazolines with Methylenecyclopropenes
Authors: Tsuge Otohiko , Tanaka Minoru , Shimoharada Hiroshi , Kanemasa Shuji
Published: July 2006

Reactions of 2-methylene-3-phenacylbenzothiazoline and 3-benzyl-2-methylenebenzothiazoline, generated in situ from the corresponding 2-methylbenzothiazolium bromide and triethylamine, with methylenecyclopropenes gave a variety of products, cross-conjugated systems, spiro-cyclopentafurans and/or cyclopentabenzothiazines, depending on the nature of substituents of the methylenecyclopropenes. The reaction pathways for the formation of products are also described.
Electronic States of Dioxygen Heme Complex Revealed from ab Initio LCAO-SCF-MO Calculations
Authors: Nozawa Tsunenori , Hatano Masahiro , Nagashima Unpei , Obara Shigeru , Kashiwagi Hiroshi
Published: July 2006

Ab initio LCAO-SCF-MO calculations of a model oxyheme were carried out on several singlet, triplet and quintet states arising from the three types of configurations, (dε)6(πga)2, (dε)5(dγ)1(πga)1(πgb)1, and (dε)5(πga)2(πgb)1. The lowest states in the SCF energy are of the configuration (dε)5(πga)2(πgb)1 whose electronic structures can be also expressed as Fe(III)–O2− from the results of Mulliken’s population analysis. Calculated Mössbauer parameters of those states are in good agreement with experiments for oxyhemoglobin, oxymyoglobin and model oxyheme, while those of the closed-shell singlet state (dε)6(πga)2 are inconsistent with experiments. The Fe–O1 overlap populations indicate a bonding nature for the former states and a non-bonding nature for the latter state. These results all predict singlet states of Fe(III)–O2− structure as the main configuration of the ground state in the model oxyheme.
Electrochemical Oxidation and Reduction of Flavin–Adenine Dinucleotide Adsorbed on a Mercury Electrode Surface
Authors: Kakutani Tadaaki , Katasho Isao , Senda Mitsugi
Published: July 2006

The electrochemical redox reaction of flavin–adenine dinucleotide (FAD) adsorbed on a hanging mercury drop electrode was studied in a pH 6.9 phosphate buffer by means of cyclic d.c. and a.c. voltammetry. Both the oxidized and reduced forms of FAD were strongly adsorbed on the mercury electrode surface. At the surface concentrations of FAD, Γ, lower than 5.0×10−11 mol cm−2, the cyclic d.c. and a.c. voltammetric behavior of adsorbed FAD was explained by the theory for a two-step one-electron surface redox reaction. The formal redox potential, semiquinone formation constant, and charge transfer rate constant for the surface redox reaction of FAD and the interaction parameter of adsorbed FAD species were determined. Cyclic d.c. voltammetry and differential capacity measurement showed that, as Γ exceeded 5×10−11 mol cm−2, the reorientation of adsorbed FAD molecules occurred. At Γ>5.8×10−11 mol cm−2, the semiquinone formation constant was very small and the behavior was interpreted by the theory of a single-step two-electron surface redox reaction. The electrochemical surface redox properties of FAD adsorbed on a mercury electrode surface appear to depend on the orientation mode of adsorbed FAD molecules.
Ylide–Metal Complexes. VII. The Preparation and Properties of IIA Group Metal(Be, Mg) and IIIA Group Metal(Al, Ga, In) Complexes of Alkylidenetriphenylphosphoranes
Authors: Yamamoto Yoshihisa
Published: July 2006

The reactions of (C6H5)3P=CH2 (L) with BeCl2 or MgCl2 in the mole ratio of 2 : 1 or 4 : 1 yield new dimeric compounds of di-μ-chloro-bis[(methylenetriphenylphosphorane)metal] dichloride, (Remark: Graphics omitted.) (M: Be and Mg). The configuration of these metals is trigonal. The reactions of L with AlCl3, GaCl3 or InCl3 in the mole ratio of 2 : 1 yield new compounds of di-μ-chloro-bis[bis(methylenetriphenylphosphorane)metal] tetrachloride, (Remark: Graphics omitted.) (M: Al, Ga, and In). The reactions of L with AlCl3 or GaCl3 in the mole ratio of 3 : 1 or 5 : 1 yield new compounds of μ-chloro-bis[tris(methylenetriphenylphosphorane)metal] pentachloride, [{(C6H5)3PCH2}3M–Cl–M{CH2P(C6H5)3}3]Cl5 (M: Al, Ga). These dimers, bridged by chloride anions, are thermally stable.
The Synthesis and Color of Pyrido[1′,2′ : 1,2]pyrimido[4,5-b]acridine-7,15-diones
Authors: Yokoyama Yasukazu
Published: July 2006

Some derivatives of pyrido[1′,2′: 1,2]pyrimido[4,5-b]acridine-7,15-diones have been synthesized, their absorption spectra have also been investigated in order to elucidate the relationship between the color and the chemical constitution in contrast to the related compounds, quinacridone and pyrido[2,1-b]pyrido[1′,2′ : 1,2]pyrimido[4,5-g]quinazoline-7,15-dione. The absorption spectra in DMSO and in concentrated sulfuric acid show a good correlation with the electronic effect of the substituents. The absorption spectra of the solid are more influenced by the position of the substituents than by the electronic effect.
Reaction of Sulfur Dichloride with Nitrile in the Presence of Lewis Acid Forming 1,2,4-Thiadiazole
Authors: Komatsu Mitsuo , Shibata Jun-ichi , Ohshiro Yoshiki , Agawa Toshio
Published: July 2006

Formation of 3,5-disubstituted 1,2,4-thiadiazoles by the reaction of sulfur dichloride with nitriles in the presence of a Lewis acid was found. For example, 3,5-diphenyl-1,2,4-thiadiazole was obtained with its chlorinated products, 3-o-chlorophenyl-5-phenyl- and 3-p-chlorophenyl-5-phenyl-1,2,4-thiadiazoles, from benzonitrile and sulfur dichloride using aluminium chloride as a catalyst (total yield 80%). The extent of chlorination of the aromatic ring was suppressed by use of iron(III) chloride as the catalyst or of sulfur chloride instead of the dichloride. Some substituted benzonitriles and pivalonitrile also gave thiadiazoles in lower yields.
Stereospecific and Stereoselective Reactions. IX. Preparation of Ethyl (2E, 7R)-7-Acetoxy-4-oxo-2-octenoate from d-Glucose
Authors: Yokota Sumio , Nishida Mitsuru , Mitsunobu Oyo
Published: July 2006

Reaction of methyl 2,3-anhydro-4,6-dideoxy-α-d-ribo-hexopyranoside with MgI2 exclusively afforded methyl 3,4,6-trideoxy-3-iodo-α-d-xylo-hexopyranoside which was dehalogenated by treatment with LiAlH4 to give methyl 3,4,6-trideoxy-α-d-erythro-hexopyranoside (2). Hydrolysis of 2 and subsequent treatment with ethoxycarbonylmethylenetriphenylphosphorane gave ethyl (2E, 4R, 7R)-4,7-dihydroxy-2-octenoate (10). Oxidation of 10 by-active MnO2 resulted in the formation of an equilibrium mixture of ethyl (2E, 7R)-7-hydroxy-4-oxo-2-octenoate (the carbon skeleton of pyrenophorin) and cyclic hemiacetal. On treatment with acetic anhydride, the mixture afforde dethyl (2E, 7R)-7-acetoxy-4-oxo-2-octenoate.
Syntheses of 1-Epikanamycin A and Its 1-N-[(S)-4-Amino-2-hydroxybutyryl] Derivative
Authors: Takahashi Yoshiaki , Tsuchiya Tsutomu , Suzuki Yukiko , Umezawa Sumio , Umezawa Hamao , Fukatsu Shunzo
Published: July 2006

The titled compounds were prepared from 3,6′-bis(N-benzyloxycarbonyl)-3″-N-(trifluoroacetyl)kanamycin A (1). Oxidation of 1 with hydrogen peroxide in the presence of sodium tungstate gave the 1-hydroxyimino derivative, which, after deblocking, gave 1-deamino-1-dehydro-1-hydroxyiminokanamycin A (6). Reduction of 6 with Raney nickel–hydrogen in aqueous ammonia gave a mixture of kanamycin A and 1-epikanamycin A (9), which were separated through derivation to the corresponding tetrakis-N-(t-butoxycarbonyl) derivatives, which showed different solubility in chloroform. 1-N-[(S)-4-Amino-2-hydroxybutyryl]-1-epikanamycin A was prepared from 9 by the zinc acetate–ethyl trifluoroacetate method [to give 3,6′-bis(N-benzyloxycarbonyl)-1-epi-3″-trifluoroacetamidokanamycin A] followed by a regiospecific 1-N-acylation with (S)-4-benzyloxycarbonylamino-2-hydroxybutyryl group and successive deblocking.
Induced Circular Dichroism of Two Chromophores Included in γ-Cyclodextrin
Authors: Kobayashi Nagao , Hino Yoshihiro , Ueno Akihiko , Osa Tetsuo
Published: July 2006

Induced circular dichroism (ICD) has suggested that γ-cyclodextrin (γ-CDx) accommodates two molecules of naphthalene and its derivatives with nearly axial inclusion but that it includes two Acridine Orange (AO) molecules with S-helicity.
The Stereoselective Dehydrative α-Glucosylation Using 6-O-Acetyl- and 6-O-p-Nitrobenzoyl-2,3,4-tri-O-benzyl-d-glucopyranoses
Authors: Koto Shinkiti , Morishima Naohiko , Kihara Yasuhiro , Suzuki Hideko , Kosugi Shigeharu , Zen Shonosuke
Published: July 2006

The stereoselective synthesis of α-linked glucobiose derivatives using 6-O-acetyl- or 6-O-p-nitrobenzoyl-2,3,4-tri-O-benzyl-d-glucopyranose and a ternary mixture of p-nitrobenzenesulfonyl chloride, silver trifluorometh-anesulfonate, and triethylamine in dichloromethane is described.
Effects of Cation on Transport Efficiency and Selectivity of Amino Acid Derivative Anions through Macrocyclic Carrier-containing Liquid Membrane
Authors: Tsukube Hiroshi
Published: July 2006

New aspects of amino acid transport mediated by macrocyclic carriers were reported. Its transport “efficiency” and “selectivity” were demonstrated to be controlled by the appropriate choice of co-transported cation and employed carrier-type.
The Structure of Aryldialkyltriazene N-Oxides
Authors: Giumanini Angelo G , Lassiani Lucia , Nisi Carlo , Petric Andrej , Stanovnik Branko
Published: July 2006

The structure of 3-aryl-1,3-dimethyltriazene 1-oxides has been demonstrated by comparison with other triazenes and triazene N-oxides by mass spectrometry and 1H and 13C NMR.
Arrhenius Parameters for the Reactions of Hydrogen and Deuterium Atoms with Four Butenes
Authors: Kyogoku Takeshi , Watanabe Toshifumi , Tsunashima Shigeru , Sato Shin
Published: July 2006

The absolute rate constants of the H and D atom addition to 1-butene, cis- and trans-2-butenes, and isobutene have been measured over the temperature range 200–500 K at the total pressure of about 600 Torr (1 Torr=133.3 Pa). The rate constants obtained were well expressed by the Arrhenius equations: k(H+1-butene)=(2.48±0.43)exp[−(1492±94)⁄RT], k(H+cis-2-butene)=(2.67±0.39)exp[−(1918±83)⁄RT], k(H+trans-2-butene)=(3.96±0.27)exp[−(2096±37)⁄RT], k(H+isobutene)=(2.08±0.16)exp[−(860±49)⁄RT], k(D+1-butene)=(2.42±0.72)exp[−(1642±169)⁄RT], k(D+cis-2-butene)=(2.25±0.19)exp[−(2082±48)⁄RT], k(D+trans-2-butene)=(2.33±0.23)exp[−(2036±55)⁄RT], and k(D+isobutene)=(1.54±0.19)exp[−(879±81)⁄RT] in units of 10−11 cm3 molecule−1 s−1. The isotope effects due to the difference between H and D atoms can simply be explained by the difference in collision frequency. The difference between cis- and trans-2-butenes in reactivity may be explained in terms of the pre-exponential factors.