bluuebunny/crossref_metadata_2025 huggingface dataset:
1,2-Carbamoyl Migration on Enantio-enriched α-Lithioalkyl Carbamates Generated with s-Butyllithium/Sparteine: Steric Course and Mechanism
Authors: Tomooka Katsuhiko , Shimizu Hideo , Inoue Tadashi , Shibata Hikaru , Nakai Takeshi
Published: September 2003

Alkyl N,N-diisopropylcarbamates, when lithiated with s-BuLi/(−)-sparteine in ether at −78 °C followed by warming to room temperature, are shown to undergo the 1,2-carbamoyl migration to give the α-hydroxy amides in >95% ee with complete retention of configuration at the Li-bearing carbanion terminus. An addition-elimination mechanism is proposed.
ESR Study on the Nature of Active Site of Silica-supported Chromia in Propane Dehydrogenation Reaction
Authors: Zou Hu , Han Yuwang , Ji Weijie , Shen Jianyi
Published: September 2003

ESR spectroscopy was used to investigate the nature of active site of CrOx/SiO2 in propane dehydrogenation reaction and Cr5+ species was proposed to be the active site for the reaction.
A Rare μ3-η1,η2 Peroxo Bridge between Two CoIIIPbII Dinuclear Units and Hydrolytic Conversion into a Hydroxo-Bridged CoIIIPbII Complex
Authors: Furutachi Hideki , Fujinami Shuhei , Suzuki Masatatsu , Okawa Hisashi
Published: September 2003

A di(μ-phenoxo)CoIIPbII complex is reversibly oxygenated to form a μ3-η1,η2 peroxo dimer that is hydrolytically converted into a hydroxo–bridged CoIIIPbII complex.
Current-Induced Low-Resistive State in Organic Mott Insulator ET-TCNQ
Authors: Kumai Reiji , Tokura Yoshinori
Published: September 2003

A molecular Mott-insulator ET-TCNQ [ET = BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene, TCNQ = 7,7,8,8-tetracyanoquinodimethane] in which carriers are localized due to the electron correlation shows extremely nonlinear electric conduction or undergoes a dielectric breakdown upon application of a high electric-field. It was demonstrated that a current-driven low-resistive state of ET-TCNQ can be stabilized down to 2 K, suggesting that the conduction path generated by the current-injection is metallic in nature.
Terephthaloyl Derivatives as New Gelators; Excellent Gelation Ability and Remarkable Increase of Gel Strength by Adding Polymers
Authors: Hanabusa Kenji , Itoh Atsushi , Kimura Mutsumi , Shirai Hirofusa
Published: September 2003

New gelators based on benzenedicarboxylic acid were synthesized, and their gelation abilities were clarified. N,N′-Terephthaloyl-bis(l-valylaminooctadecane) was especially an excellent gelator to harden a wide variety of organic fluids. The strength of gel markedly increased with addition of commercially available polymers.
Lifetime of M Intermediate in the D96N Mutant of Bacteriorhodopsin Determined by a Photoelectrochemical Method
Authors: Koyama Koichi , Miyasaka Tsutomu , Needleman Richard , Lanyi Janos K
Published: September 2003

The recombinant D96N mutant of bacteriorhodopsin (bR) was immobilized on SnO2 electrode that contacts an aqueous electrolyte. By laser pulse excitation, photocurrent behavior of D96N was analyzed to evaluate the lifetime of the M intermediate involved in proton transfer reactions. The half-life of the M intermediate in the photocycle was about 5 s, which is 103-fold longer than that of wild-type and shows the crucial role of D96 in the uptake of protons.
Silylated Chitin: A New Organosoluble Precursor for Facile Modifications and Film Casting
Authors: Kurita Keisuke , Hirakawa Masaaki , Nishiyama Yasuhiro
Published: September 2003

Trimethylsilylation of chitin and some properties of the product have been examined. Full substitution could be achieved on β-chitin under appropriate conditions. The high solubility along with easy desilylation enabled simple preparation of chitin films. Furthermore, the silylated chitin exhibited high reactivity and thus proved to be a convenient organosoluble precursor for facile modifications of this intractable biomass resource.
Spin Frustrated Double Chain {[Fe(PZDA)H2O)2]·2H2O}n (H2PZDA=2,3-Pyrazinedicarboxylic Acid)
Authors: Gao Song , Ma Bao-Qing , Yi Tao , Wang Zhe-Ming , Liao Chun-Sheng , Yan Chun-Hua , Xu Guang-Xian
Published: September 2003

A novel compound {[Fe(PZDA)(H2O)2]·2H2O}n has been synthesized and its structure determined by X-ray diffraction analysis, which consists of a quasi-ladder-like double chain running along a axis where Fe(II) ions are linked through the carboxylic groups acting as the edges of the ladder and pyrazine rings functioning as the rungs. Variable-temperature magnetic susceptibility study indicates the presence of spin frustration in the double chain compound.
Structure of Doubly-linked Oxidative Product of Quercetin in Lipid Peroxidation
Authors: Hirose Yuko , Fujita Tomoyuki , Nakayama Mitsuru
Published: September 2003

From quercetin during autoxidation of unsaturated lipid and radical reaction, a novel doubly-linked oxidative product was isolated and its structure has been characterized to be 1,3,11a-trihydroxy-9-(3,5,7-trihydroxy-4H-1-benzopyran-4-on-2-yl)-5a-(3,4-dihydroxyphenyl)-5,6,11-hexahydro-5,6,11-trioxanaphthacene-12-one by spectroscopic analyses and chemical transformation after optical resolution by chromatography.
Almost Complete Removal of Trace Amount of Halogenated Organic Compounds in Water: An Approach by Use of a Combination of Water-Soluble Thiacalixarene and Ion-Exchange Resins
Authors: Iki Nobuhiko , Fujimoto Toyohisa , Shindo Taku , Koyama Katsuyoshi , Miyano Sotaro
Published: September 2003

Two removal methods of small halogenated organic substances in water are proposed by formation of ternary complexes between the halides, thiacalix[4]arenetetrasulfonate (TCAS), and anion exchange resins, among which treatment of the polluted water with TCAS to form TCAS-guest complexes followed by trapping them onto the resin enables almost complete (more than 99.99%) removal of halogenated organic compounds such as CH2Cl2 and CHCl3.
A Novel Porphyrin Octamer with a Cyclic Tetramer Core
Authors: Okumura Akiko , Funatsu Kenji , Sasaki Yoichi , Imamura Taira
Published: September 2003

A novel porphyrin octamer with a ruthenium porphyrin tetrameric core was synthesized and characterized.
Chemiluminescence Detection in Microchip Capillary Electrophoresis
Authors: Hashimoto Masahiko , Tsukagoshi Kazuhiko , Nakajima Riichiro , Kondo Kazuo , Arai Akihiko
Published: September 2003

Chemiluminescence detection was used in microchip capillary electrophoresis. Peroxyoxalate chemiluminescence reaction was used, and dansyl amino acids were successfully separated and detected. The present system had advantages in rapid run time (within 40 s), small (several 10 pL) and accurate sample injection method, and simplification and miniaturization of detection device.
Synthesis and Pseudorotational Barriers of Hypervalent Antimony Compounds Bearing Antimony-Group 6 Transition Metal Bonds
Authors: Toyota Koichiro , Yamamoto Yohsuke , Akiba Kin-ya
Published: September 2003

Hypervalent antimony compounds Rf2Sb*M(Cp)(CO)3 (Rf = o-C6H4C(CF3)2O-, M = Cr 1, Mo 2, W 3) and diastereomeric RfRfm*Sb*Mo(Cp)(CO)3 {4a and 4b, Rfm* = o-C6H4C*(CF3)(Me)O-} were synthesized. X-ray analysis of 1 and 4a and the very high isomerization barrier (31.5 kcal/mol) of 4 showed the strong electron-donating property of the (Cp)M(CO)3 fragments.
Reversible Valence Change of the Europium Ion Doped in Alkaline-earth Tetraborates
Authors: Machida Ken-ichi , Ueda Daisuke , Inoue Satoshi , Adachi Gin-ya
Published: September 2003

Valence state of the europium (Eu) ion doped in MB4O7 (M = Sr and Ba) was reversibly changed between the trivalent and divalent state by repeating the crystallization and vitrification cycle of the host lattices by heating even in air at 973-1273 K and such valence change was discussed on the basis of their structural connection manner for the BO3 and/or BO4 units in the networks of crystalline and vitreous forms.
Formation of Mesoscopic Patterns with Molecular-Level Flatness by Simple Casting of Chloroform Solutions of Tripeptide-Containing Amphiphiles
Authors: Ariga Katsuhiko , Kikuchi Jun-ichi , Narumi Kikou , Koyama Emiko , Yamada Norihiro
Published: September 2003

An AFM investigation revealed that air-dried cast films of tripeptide-containing amphiphiles had a flat texture with regular mesoscopic patterns.
Luminescent pH Sensors Based on Ru(bpy)2L2+ Where L Are Imidazo[f]1,10-phenanthrolines
Authors: Jing Bingwen , Song Aimin , Zhang Manhua , Shen Tao
Published: September 2003

The luminescence quantum yield of Ru(bpy)2L2+ complexes where L are imidazo[f]1,10-phenanthrolines is strongly controlled by pH due to intramolecular photoinduced electron transfer.
Synthesis and X-Ray Structures of Arsenic(V) Porphyrins with Symmetric Diaxial Ligands of Me2 and F2
Authors: Yasumoto Manabu , Satoh Wataru , Nadano Ryo , Yamamoto Yohsuke , Akiba Kin-ya
Published: September 2003

Arsenic porphyrins [(TPP)As(Me)2]+PF6− (2-PF6), [(TPP)As(F)2]+PF6− (3-PF6), and [(OEP)As(F)2]+PF6− (4-PF6) were prepared and the X-ray crystallographic structures revealed that the axial ligand and the porphyrin core affected to control the conformation of the porphyrins.
Preparation and Magnetic Property of Sm2Fe17Nx Fine Powders Coated by Zn and In Metals Produced via Photodecomposition of Their Organometallic Compounds
Authors: Noguchi Kenji , Nishimura Masashi , Machida Ken-ichi , Adachi Gin-ya
Published: September 2003

Fine powders of Sm2Fe17Nx were stabilized by microcapsulation with the In and Zn metals produced via photochemical decomposition of In(C2H5)3 and Zn(C2H5)2 under UV light irradiation and were molded to high-performance In metal-bonded magnets with the highest (BH)max value of 144 kJm−3 for Hcj = 0.66 MAm−1 among the metal-bonded Sm2Fe17Nx magnets reported up to date.
Reversal of Diastereoselectivity of the Reaction of Chiral Boron and Titanium Enolates with Nitrones via N-Acyloxyiminium Intermediates. Asymmetric Synthesis of Diastereomeric α-Substituted β-Amino Acids
Authors: Kawakami Toru , Ohtake Hiroaki , Arakawa Hiroaki , Okachi Takahiro , Imada Yasushi , Murahashi Shun-Ichi
Published: September 2003

Reaction of nitrones and acyl halides gives N-acyloxyiminium species, which are more reactive toward soft carbon nucleophiles than nitrones. Addition of chiral enolates to the N-acyloxyiminium species gave N-hydroxy-β-amino acid derivatives highly diastereoselectively. Reversal of diastereoselectivity was observed between the boron enolates and titanium enolates. Using this method all of the four stereoisomers of α-methyl-β-phenylalanines can be prepared as enantiomerically pure forms.
Incorporation of La3+ in an Organic Network. A Polyphenol-Derived Solid Brønsted-Base Catalyst
Authors: Saiki Toshiyuki , Aoyama Yasuhiro
Published: September 2003

Treatment of anthracenebisresorcinol 1 (a tetraphenol) with La(OiPr)3 in THF affords an amorphous 1:2 (14− to La3+) coordination polymer (La host). It catalyzes typical base-promoted reactions such as Michael, nitroaldol, and, less effectively, aldol reactions, where the insoluble catalyst (La host) can be readily recovered and repeatedly used.
Synthesis of N-Isopropylacrylamide from Acrylonitrile and Isopropyl Alcohol over H-ZSM-5
Authors: Chen Xin , Matsuda Hideho , Okuhara Toshio
Published: September 2003

A solid acid, H-ZSM-5 (Si/Al = 37), exhibited exceptionally high catalytic performance for synthesis of N-isopropylacrylamide from acrylonitrile and isopropyl alcohol in a solid-liquid reaction system at 423 K.
Difference in Catalytic Combustion of Propane and Propene on Pt/Al2O3 Catalyst
Authors: Chiba Akiya , Komoda Mitsutaka , Kosumi Takaaki , Nanba Tetsuya , Azuma Naoto , Ueno Akifumi
Published: September 2003

Propene combustion on Pt/Al2O3 catalysts was enhanced when partial pressure of oxygen in a feed increased, while propane combustion was found to be depressed when partial pressure of oxygen was higher than the stoichiometric pressure.
Contrasting Regiochemistry in Thermal and Photochemical Allylstannations of 1,2-Naphthoquinone
Authors: Nishigaichi Yutaka , Yoshida Naofumi , Matsuura Mikiya , Takuwa Akio
Published: September 2003

1,2-Naphthoquinone with γ-substituted allyltin reagents undergoes both thermal and photochemical reactions, which show the opposite regioselectivities to each other. The both reactions are supposed to proceed via the initial 1,2-addition, which occurs at the γ-position of the allyltin in the thermal reaction and at the less hindered α-position in the photoreaction, followed by the [3,3] allylic migration.
Transient Spectra and Photoreaction of 4-Methoxybenzoyloxyl Radical
Authors: Oishi Shigero , Tsubaki Hirotaka , Matsuzawa Hideyo
Published: September 2003

An absorption maximum and a molar extinction coefficient of a transient in the laser flash photolysis of bis(4-methoxybenzoyl) peroxide were determined as 900 nm and 750 M−1cm−1, respectively. The comparison of products for the photolysis at 266 nm with and without 1064-nm pulse gave a solid evidence of 4-methoxybenzoyloxyl radical being responsible for the absorption.
Syntheses of Novel Cyclic Polyethers and Their Complexation with Benzene Derivatives
Authors: Choi Wonmun , Hiratani Kazuhisa
Published: September 2003

Cyclic polyethers have been synthesized from the hydroquinone and methallyl (isobutenyl) dichloride. Of these, only the tetramer forms 1:1 complexes with benzene derivatives.
Coordination Behavior of Ruthenium(II) Complexes with Alcohol Ligand Tethered to η6-Arene Donor
Authors: Ohnishi Takafumi , Miyaki Yoshiharu , Asano Hideo , Kurosawa Hideo
Published: September 2003

Some ruthenium(II) complexes of an alcohol ligand tethered to η6-arene group have been prepared. The alcohol-Ru chelate bond of the complexes containing an N,N′-chelate auxiliary was maintained in methanol. The Cl− ion cleaved the alcohol-Ru bond to give the Ru-Cl bond, while bases (OH−, RNH2) abstracted proton of OH bound to Ru affording the alkoxy chelate complex.
Low-temperature Synthesis Routes of Alkali-metal Molybdenum Bronzes
Authors: Eda Kazuo , Chin Kin , Whittingham M Stanley
Published: September 2003

We found some novel synthesis routes for alkali-metal molybdenum bronzes. The synthesis techniques are composed of simple hydrothermal treatments of mixed-valence compounds (or mixtures) with ACl or ACl + AOH aqueous solutions (A = alkali metal). Using these routes blue bronze (K0.30MoO3) and red bronze (K0.33MoO3) were obtained from hydrogen molybdenum bronze HxMoO3 or HxMoO3 + MoO3 even at 410 K.
A Transition Metal-Hydroperoxo Complex Stabilized by Hydrogen-Bonding Interaction: The First Example of a Hydroperoxopalladium Species Characterized by X-Ray Crystallography, (κ2-TpiPr)Pd(PPh3)(OOH) [TpiPr = hydrotris(3,5-diisopropylpyrazolyl)borato]
Authors: Akita Munetaka , Miyaji Taichi , Hikichi Shiro , Moro-oka Yoshihiko
Published: September 2003

(κ2-TpiPr)Pd(PPh3)-OOH, the first example of a structurally characterized hydroperoxopalladium species, contains hydrogen-bonding interaction between the OOH moiety and the non-coordinated pyrazolyl ring.
Synthesis, Aggregate Structure and Electrochemical Properties of a Water-Soluble Fullerene-Bearing Ammonium Amphiphile
Authors: Murakami Hiroto , Shirakusa Masaharu , Sagara Takamasa , Nakashima Naotoshi
Published: September 2003

A water-soluble C60-terminating ammonium surfactant, 1, was synthesized. Electron microscopy revealed that 1 forms a fibrous aggregate in an aqueous solution. Electronic interaction between the fullerene moieties in 1 in the aqueous solution was observed. Electrochemistry for 1 aqueous solutions was found to be quite different from that of 1 in the film states.
Synthesis of 18-Demethyltaxoid via Stereoselective Allylation and Intramolecular Aldol Condensation Reactions
Authors: Iwadare Hayato , Sakoh Hiroki , Arai Hidehiro , Shiina Isamu , Mukaiyama Teruaki
Published: September 2003

Optically active novel 18-demethyltaxiods were successfully synthesized from 2α,10β-dibenzyloxy-11β-(t-butyldimethylsiloxy)-7β-hydroxy-1α-(p-methoxybenzyloxy)-8β,15,15-trimethyl-4-methylene-trans-bicyclo[6.4.0]dodecan-9-one (2) which corresponds to the BC ring system of Taxol by stereoselective allylation and intramolecular aldol condensation reactions.
The Crystal Structure and Magnetic Properties of CuII-NiII Heterodinuclear Complex with N,N′-Bis(2-pyridyl-ethyl)-oxamide Dianion
Authors: Liu Bin , Liao Daizheng , Jiang Zonghui , Yan Shiping , Wang Genglin , Yao Xinkan , Wang Honggen
Published: September 2003

A new CuII-NiII heterodinuclear complex [Cu(PEoxd)Ni(bpy)2](ClO4)2·1/2H2O has been synthesized and its structure determined by single crystal X-ray analysis. Crystal data: space group P21/c with a = 9.226(2) Å, b = 30.857(6) Å, c = 14.241(3) Å, and β = 97.36(3)°, V = 4021(2) Å3, Z = 4. Magnetic measurement indicates that the overall magnetic behavior is weakly antiferromagnetic.
Copper(I) Iodide-Promoted Allylation of Allyl- and Vinyl-silanes Assisted by Intramolecular-Coordination
Authors: Takeda Takeshi , Uruga Tetsuya , Gohroku Kazushi , Fujiwara Tooru
Published: September 2003

The allylation products, 1-(2-pyridylthio)alk-1,5-dienes, were produced regioselectively when 1-(2-pyridylthio)-1-(trimethylsilyl)alk-2-enes were treated with allylic chlorides in the presence of CuI and KF. The similar reaction of 1-(2-pyridylthio)-1-(trimethylsilyl)alk-1-enes with allylic chlorides produced the 1,4-dienes with complete retention of configuration.
In situ Monitoring of Poly(l-glutamine)-Bound dsDNA Selection on a Quartz-Crystal Microbalance
Authors: Furusawa Hiroyuki , Ebara Yasuhito , Okahata Yoshio
Published: September 2003

We applied a highly sensitive quartz-crystal microbalance as a device of dsDNA in vitro selection. When poly((l-glutamine)-immobilized QCM was employed, both the selection and evaluation processes could be monitored in situ as mass changes, and the dsDNAs having the continuous sequences of 3-5 AT base-pairs were selected after the 4th cycle from a random dsDNA pool.
Methylenation of Esters with Bis(iodozincio)methane-TiCl2-TMEDA System
Authors: Matsubara Seijiro , Ukai Katsumi , Mizuno Tsuyoshi , Utimoto Kiitiro
Published: September 2003

Methylenation of ester carbonyl group with bis(iodozincio)methane was examined: a use of TiCl2 and amine as mediators facilitated the reaction to give vinyl ethers in good yields.
An Efficient and Rapid Regeneration of Carbonyl Compounds from Their N,N-Dimethylhydrazones in Presence of Chlorotrimethylsilane/Sodium Iodide
Authors: Kamal Ahmed , Ramana K Venkata , Arifuddin M
Published: September 2003

A new efficient and extremely facile regeneration of carbonyl compounds from their N,N-dimethylhydrazones is developed in presence of chlorotrimethylsilane/sodium iodide.
Enhanced Acidity and Thermal Stability of Mesoporous Materials with Post-treatment with Phosphoric Acid
Authors: Huang Limin , Li Quanzhi
Published: September 2003

The thermal stability and acidity of mesoporous materials can be greatly improved through the impregnation of phosphoric acid. The P-modified Al-MCM-41 shows potential application in the cracking of long-chain alkane for producing gas olefins, especially iso-butene.
Diastereo-Differentiation during 2,4-Pentanediol Tethered Simmons-Smith Type Cyclopropanation: Reaction Species of Hydroxyl Group Directed Zinc Carbenoid Addition
Authors: Sugimura Takashi , Yoshikawa Masato , Mizuguchi Miki , Tai Akira
Published: September 2003

The predominant formation methods for the diastereo-differentiating species of zinc carbenoid addition to the 1-cyclohexenyl ether carrying the 2,4-pentanediol moiety were established. The species were found to include two zinc atoms and one carbenoid carbon at the hydroxyl group.
3,5-Di-tert-butylphenyl (DtBuP) Group as a Protecting Group for Kinetic Stabilization. Preparation and Characterizatioin of 2,6-Naphthoquinone Skeleton
Authors: Sugiura Ken-ichi , Saika Masataka , Sakata Yoshiteru
Published: September 2003

A potential use of a 3,5-di-tert-butylphenyl group for kinetically stabilization and the isolation of a stabilized 2,6-napthoquinone derivative are discussed.
Thermally Reversible Photochromic Systems. Photochromism of a Dipyrrolylperfluorocyclopentene
Authors: Uchida Kingo , Matsuoka Toyokazu , Sayo Koichi , Iwamoto Masahiro , Hayashi Shigehiko , Irie Masahiro
Published: September 2003

A diarylethene having 2-cyanopyrrole rings turned blue upon UV irradiation in ethyl acetate. The colored form was unstable and returned to the colorless open-ring form with a half-life time of 37 s at room temperature. The activation energy of the thermal fading was obtained to be 32.5 kJ / mol, which is less than half of that of spironaphthoxazine.
Solid-Surface Fluorescence Enhancement Behavior of a Benzofuranoquinol-Type Fluorescent Host upon Enclathration of Alicyclic Amines
Authors: Yoshida Katsuhira , Miyazaki Hirofumi , Miura Yumi , Ooyama Yousuke , Watanabe Shigeru
Published: September 2003

A novel benzofuranoquinol-type fluorescent host which exhibits sensitive color change and fluorescence enhancement behavior upon enclathration of alicyclic amines has been developed. The X-ray crystal structures of the guest-free and morpholine inclusion compounds have been elucidated, on the basis of which the mechanism of the optical sensing is discussed.
A New Solvothermal-Reduction Pathway to Nanocrystalline MTe (M = Zn, Pb)
Authors: Yang Jian , Yu Shu-Hong , Yang Xue-Liang , Qian Yi-Tai
Published: September 2003

A novel solvothermal-reduction pathway (SRP) to nanocrystalline metal tellurides (MTe, M = Zn, Pb) has been established by the reaction of metal salts with tellurium in various solvents in the presence of hydrazine hydrate(N2H4·H2O) as a reducing agent. Nanocrystallites with different morphologies such as cube particles and similar-rectangular flakes were obtained under mild conditions. The effects of solvents and temperature on the reactions were investigated.
X-Ray Photoelectron Spectroscopy of Metallo Porphyrins Having Bulky Substituents: Standard Values of Core Ionization Potentials
Authors: Sugiura Ken-ichi , Iwasaki Kentaro , Umishita Kazunori , Hino Shojun , Ogata Hironori , Miyajima Seiichi , Sakata Yoshiteru
Published: September 2003

X-ray photoelectron spectra of four porphyrins which hardly aggregate were measured. The C1s and N1s peak positions of these porphyrins showed almost identical values, so that these values can be used as a standard.
A Novel Route to (η3-Allyl)dicarbonylnitrosyliron Complexes via Transmetallation of η3-Allyl Palladium Complexes
Authors: Nakanishi Saburo , Yasui Masashi , Kihara Nobuhiro , Takata Toshikazu
Published: September 2003

Treatment of (η3-allyl)bromopalladium complexes with tricarbonylnitrosyl ferrate [Fe(CO)3(NO)]−1 afforded (η3-allyl)dicarbonylnitrosyliron complexes in good yields. The reaction provides a new route to (η3-allyl)dicarbonylnitrosyliron complexes by transmetallation of the η3-allyl ligand from palladium to iron metal.
New Stable Metallic Salt Based on a Donor Molecule Containing peri-Ditellurium Bridges, TMTTeN(SCN)0.88
Authors: Ojima Emiko , Narymbetov Bakhyt Zh , Fujiwara Hideki , Kobayashi Hayao , Kobayashi Akiko , Takimiya Kazuo , Otsubo Tetsuo , Ogura Fumio
Published: September 2003

A new stable organic metal, TMTTeN(SCN)0.88, where TMTTeN is 2,3,6,7-tetramethylnaphtho[1,8-cd:4,5-c′d′]bis[1,2] ditellurole, was obtained. The donors are stacked to form columns and three-dimensional network is developed through Te···Te contacts. The salt is highly conductive and keeps metallic behavior down to 4.2 K. Furthermore the salt exhibits Pauli paramagnetic behavior down to 2 K. The extended Hückel tight-binding band calculation was examined.
Photoreduction of N,N′-Bridged Porphyrins to 20π Antiaromatic Isophlorins
Authors: Setsune Jun-ichiro , Kashihara Kenji , Wada Ken-ichi , Shiozaki Hisayoshi
Published: September 2003

20π Antiaromatic isophlorins of N21,N22-bridged N23-alkyl-porphyrins were prepared through photoreduction with N-benzyl-1,4dihydronicotinamide or intramolecular nucleophilic alkylation at the N(24)-position. The ring structure of these N21,N22-bridged isophlorins is not highly deviated from planarity and their antiaromaticity was indicated by the great paramagnetic ring current effect.
A Potential Chemical Source of C2
Authors: Pan Weitao , Armstrong Brian M , Shevlin Philip B , Crittell Charles H , Stang Peter J
Published: September 2003

Thermolysis of ethynyl(phenyl)iodonium triflate, 1, in the presence of cyclooctatetraene generates naphthalene in a reaction involving free C2 or in which 1 acts as a C2 donor.
Abrasive Stripping Voltammetry at Polycrystalline Diamond Electrodes
Authors: Manivannan A , Tryk D A , Fujishima A
Published: September 2003

We present a new approach for the electrochemical fingerprinting of a wide range of materials using abrasive differential pulse stripping voltammetry (AbrDPSV) at boron-doped diamond electrodes. In this study, the abrasive stripping voltammetry of metallic Pb and Fe samples and of a brass alloy sample at diamond electrodes was carried out. The results obtained with brass indicate that the differential pulse voltammogram is an electrochemical fingerprint of the material and can be used to characterize possible interactions between the constituent metals as well as to reveal information on the chemical composition.
Attachment of an Organic Dye on a TiO2 Substrate in Supercritical CO2: Application to a Solar Cell
Authors: Bando Kyoko Kitamura , Mitsuzuka Yukiko , Sugino Maki , Sugihara Hideki , Sayama Kazuhiro , Arakawa Hironori
Published: September 2003

Attachment of eosin Y onto TiO2 electrode was carried out using super critical CO2 as a solvent. The solar cell composed of an electrode which prepared under the condition of 493 K and 25 MPa in super critical CO2 , showed an efficient fill factor as high as 95% (a Xe lamp with a 517 nm band pass filter). The dye was supposed to keep its structure under such sever conditions. Super critical CO2 made possible to carry out the attachment of dye at high temperature in a uniform phase.
New Efficient Method for the Stereoselective Synthesis of α-(Trifluoromethyl)-α, β-unsaturated Amides. Lewis Acid-Catalyzed Reaction of 3,3,3-Trifluoro-1-propynylamine with Carbonyl Compounds
Authors: Mantani Toshiya , Shiomi Keisuke , Ishihara Takashi , Yamanaka Hiroki
Published: September 2003

N,N-Dibutyl-(3,3,3-trifluoro-1-propynyl)amine, prepared readily by the dehydrofluorination of N,N-dibutyl-(2,2,3,3,3-pentafluoropropyl)amine with lithium diisopropylamide at room temperature, smoothly reacted with a variety of aldehydes and ketones in the presence of a catalytic amount of Lewis acid and molecular sieves 4A at ambient temperature to give the corresponding α-(trifluoromethyl)-α,β-unsaturated amides in good to excellent yields with high Z stereoselectivity.
Iodine-Catalyzed Mild and Efficient Tetrahydropyranylation / Depyranylation of Alcohols
Authors: Kumar H M Sampath , Reddy B V Subba , Reddy E Jagan , Yadav J S
Published: September 2003

Alcohols and phenols are tetrahydropyranylated rapidly in high yields in the presence of catalytic amount of iodine at room temperature. Depyranylation is effected readily by refluxing with iodine in methanol for few hours.
Structures and Properties of (TMEO-ST-TTP)2AsF6
Authors: Misaki Yohji , Taniguchi Masateru , Tanaka Kazuyoshi , Takimiya Kazuo , Morikami Atsushi , Otsubo Tetsuo , Mori Takehiko
Published: September 2003

The title material, where TMEO-ST-TTP is 2-[4,5-bis(methylthio)-1,3-diselenol-2-ylidene)-5-(4,5-ethylendioxy-1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalene, shows metallic conducting behavior down to 4.2 K. X-Ray structure analysis reveals it has the β-type array of donors in the BEDT-TTF salts. A tight-binding band calculation suggests the present salt has a quasi-one-dimensional Fermi surface.
Structure of Azabismocines, Hexacoordinate Pentavalent Organobismuth Compounds
Authors: Minoura Mao , Kanamori Yuka , Miyake Akira , Akiba Kin-ya
Published: September 2003

Azabisomocine derivatives having a pentavalent bismuth and a nitrogen at 1,5-position were synthesized. The X-ray structural analysis reveals that these compounds have hexacoordinate distorted octahedral geometry which is caused by transannular bond formation between the bismuth and the nitrogen.
Novel Palladium-Catalyzed Thiophosphorylation of Alkynes with Phosphorothioate: An Efficient Route to (Z)-1-(Diphenoxyphosphinyl)-2-(Phenylthio)alkenes
Authors: Han Li-Biao , Tanaka Masato
Published: September 2003

Palladium complexes efficiently catalyze the addition of O,O,S-triphenyl phosphorothioate to terminal alkynes to produce (Z)-1-(diphenoxyphosphinyl)-2-(phenylthio)alkenes in high yields with high regio- and stereoselectivity.
Synthesis, Structure, and Reactivities of the η1:η6-μ2-Aryl Alkynyl Diruthenium Complex. X-Ray Structure of [Cp(PPh3)2Ru(η1:η6-μ2-C≡CC6H4Me-p)RuCp*]PF6 (Cp = η5-C5H5, Cp* = η5-C5Me5)
Authors: Matsuzaka Hiroyuki , Sato Yoshiyuki , Okimura Hironobu , Ishii Tomohiko , Yamashita Masahiro , Kitagawa Susumu , Kondo Mitsuru , Shiro Moto-o , Yamasaki Mikio
Published: September 2003

Preparation of a η1:η6-μ2-aryl alkynyl diruthenium complex [Cp(PPh3)2Ru(η1:η6-μ2-C≡CC6H4Me-p)RuCp*]Cl (2•Cl) [Cp = η5-C5H5, Cp* = η5-C5Me5] and its reactions with electrophile or CO are reported. The structure of 2•PF6 has been determined by X-ray crystallography.
Synthetic Study of C-1027 Chromophore. Highly Stereoselective Glycosylation
Authors: Sato Itaru , Akahori Yuri , Sasaki Takeo , Kikuchi Tsukasa , Hirama Masahiro
Published: September 2003

A highly stereoselective method for glycosylation of tertiary alcohols with the amino sugar moiety of C-1027 chromophore was developed.
H-D Exchange Reaction of Borane-Lewis Base Adducts by Rhenium Polyhydride Complexes
Authors: Kakizawa Taeko , Kawano Yasuro , Shimoi Mamoru
Published: September 2003

Heating of a benzene-d6 solution of BH3·L (L = PMe3, NMe3) and [ReH7(PPh3)2] resulted in the formation of the deuterated boranes, BH3−nDn·L (n = 0–3). Deuteration of BH3· L with [ReH5(PR3)3] (PR3 = PPh3, PPhMe2) required photoirradiation. The mechanism of the H-D exchange is discussed.
Partial Oxidation of Methane with Nitrous Oxide in a Dielectric-Barrier Discharge System
Authors: Tanabe Shuji , Egashira Kayo , Okitsu Kenji , Matsumoto Hiroshige
Published: September 2003

The partial oxidation of CH4 by N2O was investigated in a dielectric-barrier discharge system at atmospheric pressure. CH4 converted to CH3OH, HCHO, and CO in this system. Total yield of CH3OH and HCHO reached about 10% in the Ar stream. It was suggested that excited Ar species and electrons might behave important role to promote the partial oxidation reaction.
Effect of H2 Flow Rate in Reduction Process on the Catalytic Properties of Reduced MoO3
Authors: Matsuda Takeshi , Hirata Yasuyoshi , Suzuki Masaki , Sakagami Hirotoshi , Takahashi Nobuo
Published: September 2003

Catalytic activities of reduced MoO3 for the conversions of heptane and 2-propanol were markedly enlarged by an increase in the flow rate of H2 in reduction. The degree of reduction and the surface area were found to depend on the H2 flow rate. These phenomena seem to be induced by action of H2O produced by reduction.
γ-Irradiation Route to Nanocrystalline Lead Selenide
Authors: Xie Yi , Qiao Zhengping , Chen Meng , Zhu Yingjie , Qian Yitai
Published: September 2003

30 nm PbSe has been synthesized for the first time by γ-irradiation method from an ethylenediamine solution containing lead acetate and elemental selenium at room temperature and in ambient pressure.
Novel Dependence of the Bond Cleavage Pattern of Bis(2-phenylbenzoyl) Peroxide on the Irradiation Wavelength
Authors: Karatsu Takashi , Yoshita Yasuhiro , Fukui Keijiro , Kitamura Akihide
Published: September 2003

Bis(2-phenylbenzoyl) peroxide (2-PhBPO) photodecomposed by 100% O–O bond cleavage to give mainly biphenyl-2,2′-carbolactone on 313 nm irradiation, however, on 254 nm, the photodecomposition proceeded through 60% two bonds cleavage (simultaneous C–C and O–O bonds cleavage).
Thermal Hetero [3 + 2] Cycloaddition of Dipolar Trimethylenemethane to N-Sulfonyl and N-Acyl Imines. Synthesis of γ-Amino Acid Derivatives
Authors: Yamago Shigeru , Yanagawa Masao , Nakamura Eiichi
Published: September 2003

Thermal hetero [3 + 2] cycloaddition reaction of a dipolar trimethylenemethane 2 with an N-acyl or N-tosyl imine gives an α-methylene-γ-pyrrolidone acetal 4 in high yield, which upon hydrolysis affords a γ-amino acid derivative.
Convenient Preparation of Novel Calix[n]cryptands (n = 4, 6)
Authors: Li Jian-Sen , Chen Yuan-Yin , Zhong Zhen-Lin , Lu Xue-Ran , Zhang Tao , Yan Jiang-Li
Published: September 2003

Convenient syntheses of novel tripodal calix[4]cryptand and the first example of 1,2,4-tripodal calix[6]cryptand were reported by direct condensation of p-tert-butylcalix[4]arene or p-tert-butylcalix[6]arene with 1,1,1-tri(tosyloxyethoxyethoxymethyl)-propane. Besides, a novel type of doublecalix[4]arenes and a novel type of calix[6]crown, were co-prepared, respectively. It was suggested that the synthetic strategy described in this paper may be genegally useful to explore the little-known field of calixcryptands.
Molecular Orbital Calculations for Discoloration of Titanylphthalocyanine and Titanylporphyrin by Silyl Radical
Authors: Sakurai Yoshiaki , Shiozaki Hisayoshi , Yokoyama Masaaki
Published: September 2003

The reactivities of a silyl radical and porphyrins or phthalocyanines were studied using the index, ΔN, derived from “hard and soft acids and bases” concept. The silyl radical and titanyl derivatives were assigned as an electron donor and acceptors, respectively, in the reaction system. The order of the value of ΔN was in well agreement with the experimental result of the discoloration reaction.
Photodecomposition of 4-Chlorophenol Catalyzed by Titanium Silicalite-2
Authors: Kang Man Gu , Hong Jin Sup , Kim Kang-Jin
Published: September 2003

The photodegradation reaction rate of 4-chlorophenol (4-CP) with a titanium silicalite–2 (TS-2) catalyst is found to be faster in the initial stage than with TiO2. This is primarily due to the stronger adsorption of 4-CP on the hydrophobic surface of the TS-2 catalyst. The hydrophobicity is evaluated by determining the distribution coefficients (D) between TS-2 and aqueous medium using a variety of aromatic hydrocarbons. The larger the D, the faster the initial reaction rate. The D correlates with solubility in water and partition coefficient, log Poct.
A Hydrogen-Bonded Molecular Ladder. The Crystal Structure and Guest-Binding Properties of a Bishydroquinone Derivative of Anthracene
Authors: Tanaka Ken-ya , Endo Ken , Aoyama Yasuhiro
Published: September 2003

9,10-Bis(2,5-dihydroxy-1-phenyl)anthracene, an H-shaped tetraphenol, forms a doubly hydrogen-bonded ladder-like polymeric chain in the crystal. The small in-ladder cavities incorporate tiny guests such as acetone selectively.
Molecular Brush Having Molten Salt Domain for Fast Ion Conduction
Authors: Yoshizawa Masahiro , Ohno Hiroyuki
Published: September 2003

Poly(ethylene oxide) (PEO) derivatives having both vinyl group and imidazolium salt structure on their ends were prepared and polymerized. When molten salt domain was provided by changing chloride anion with bis(trifluoromethanesulfonylimide) anion, excellent ionic conductivity (1.20 × 10−4 Scm−1 at 30 °C) was observed in spite of rubber-like properties.
Polymerization of Polar Vinyl Monomers with Novel Cobalt-based Catalyst
Authors: Tsuchihara Kenji , Suzuki Yasuzo , Asai Michihiko , Soga Kazuo
Published: September 2003

Cobalt-based complex CH3C(CH2PPh2)3Co(BH4) (1) polymerized polar vinyl monomers like acrylonitrile (AN) and methyl methacrylate (MMA) without any cocatalysts. The molecular weight of the poly(AN) was fairly high at around 500 × 103. It was concluded that the polymerizations did not proceed with radical polymerization mechanism based on the copolymerization results with styrene. The obtained poly(AN) had an atactic structure.
Synthesis of Aliphatic Polyester by Insertion of Glycols into Polyanhydrides Using Lipase Catalyst
Authors: Uyama Hiroshi , Wada Satoshi , Kobayashi Shiro
Published: September 2003

Polyester synthesis was carried out by insertion-dehydration of glycols into polyanhydrides using Candida antarctica lipase as catalyst. The insertion of 1,8-octanediol into poly(azelaic anhydride) took place under mild reaction conditions to give the corresponding polyester with molecular weight of several thousands.
Acceleration of Photoinduced Charge Separation in Porphyrin-C60 Dyad with an Acetylene Spacer
Authors: Yamada Koji , Imahori Hiroshi , Nishimura Yoshinobu , Yamazaki Iwao , Sakata Yoshiteru
Published: September 2003

A porphyrin-C60 dyad with an acetylene spacer has been synthesized for the first time. The rate constant for charge separation in the dyad is larger by a factor of about three compared with a porphyrin-C60 dyad with an amide spacer, showing that the triple bond is a good electron transfer mediator.
Trifluoromethyl-substituted Norbornadiene, Useful Solar Energy Material
Authors: Nagai Takabumi , Takahashi Ikuko , Shimada Miwa
Published: September 2003

Trifluoromethyl (CF3)-substituted NBD derivatives, which not only produce thermally stable QC derivatives but also absorb visible light efficiently, were synthesized. These NBD derivatives exhibited efficient fatigue resistance.
Photo-Assisted Hydrogen Transfer from Alcohol to Limonene Catalyzed by [Rh6(CO)16]
Authors: Yanagawa Akihisa , Hatae Tomomi , Yada Satoru , Sugimori Akira , Takagi Yuzuru
Published: September 2003

Partial hydrogenation of the exo-olefinic bond in limonene to carvomenthene proceeds smoothly by photocatalytic hydrogen transfer from 2-propanol using [Rh6(CO)16] as a catalyst under UV-irradiation in the presence of acetone. Hydrogen gas evolves after the formation of carvomenthene has been completed. 1-Hydroxy-1-methylethyl radical formed in the reaction of photochemically excited acetone with 2-propanol serves both as an activator for the catalyst and as a hydrogen source.
Photooxidation of Propene to Propene Oxide by Molecular Oxygen over Zinc Oxide Dispersed on Silica
Authors: Yoshida Hisao , Murata Chizu , Hattori Tadashi
Published: September 2003

Dispersed zinc oxide species on silica, which exhibited different UV-vis absorption spectrum from bulk ZnO, promoted selective photooxidation of propene by molecular oxygen to propene oxide.
The Use of N,N-Bis(hydroxybenzyl)ethylenediamine-N,N-diacetic Acid (HBED) for the Determination of Trivalent Metal Ions by Capillary Electrophoresis
Authors: Krokhin Oleg V , Hoshino Hitoshi , Shpigun Oleg A , Yotsuyanagi Takao
Published: September 2003

The separation of Bi(III), Sc(III), In(III), Co(III), Ga(III), Al(III), Cr(III), Mn(III), and Fe(III) ions with HBED (Figure 1) by an ion exchange variant of electrokinetic chromatography was demonstrated. The use of high concentration of cationic polymer and a careful choice of counter ions added in carrier electrolyte allowed to stretch selectivity scale for the complete baseline resolution of all studied chelates with efficiency 40-300 thousands theoretical plates. Favorable arrangement of donor groups in HBED structure made possible the first separation of Ga(III) and In(III) chelates by CE.
Novel Photochromic Conducting Polymer Having Diarylethene Derivative in the Main Chain
Authors: Kawai Tsuyoshi , Kunitake Tomokatsu , Irie Masahiro
Published: September 2003

A conducting polymer having photochromic diarylethene units in the main chain was synthesized. Reversible photochromism was observed in solid film, and photoluminescence and electrical conductivity were found to change along with the photoisomerization.
Synthesis and Magnetic Properties of a New Prussian Blue Analog Composed of K0.9MnII1.05[MoI(CN)5(NO)]·5H2O·1.9MeOH
Authors: Machida Naoko , Ohkoshi Shin-ichi , Zhong Zhuang J , Hashimoto Kazuhito
Published: September 2003

We have prepared a new molybdenum polycyanide K0.9MnII1.05[MoI(CN)5(NO)]·5H2O·1.9MeOH with a face-centered cubic structure with a lattice constant of 10.72 Å. This compound exhibited a spontaneous magnetization with a Curie temperature of 39 K and a saturated magnetization value (IS) of 3.8 μB. This IS value and magnetic susceptibility measurements indicate that the magnetic coupling between MnII and MoI ions is antiferromagnetic.
Direct Evidence of the Hydrogen Atom Transfer in Methyl Salicylate in the Triplet State
Authors: Norikane Yasuo , Arai Tatsuo
Published: September 2003

Intramolecular hydrogen atom transfer in the triplet state of methyl salicylate has been studied by means of transient absorption spectroscopy. Based on the results, it has been revealed that methyl salicylate forms the keto form in the triplet state.
Hydrothermal Synthesis of Brookite
Authors: Nagase Takako , Ebina Takeo , Iwasaki Takashi , Hayashi Hiromichi , Onodera Yoshio , Chatterjee Maya
Published: September 2003

Hydrothermal synthesis of brookite was performed at 110-200 °C within 24 h using amorphous TiO2 and sodium salts as the starting material. Brookite was obtained as an almost single phase at 200 °C and TiO2 / NaOH mole ratio ≅ 1. By the results of XPS and UV-vis measurements, brookite was considered to be formed from sodium titanate by releasing Na+ and H+ of the surface accompanied by oxidation of Ti in the structure.
A New Type of Orally Active Insulin-Mimetic Vanadyl Complex: Bis(1-oxy-2-pyridinethiolato)oxovanadium(IV) with VO(S2O2) Coordination Mode
Authors: Sakurai Hiromu , Sano Hiromi , Takino Toshikazu , Yasui Hiroyuki
Published: September 2003

A new purple vanadyl complex, bis(1-oxy-2-pyridinethiolato)oxovanadium(IV), VO(OPT), with VO(S2O2) coordination mode, was prepared by mixing 2-mercaptopyridine-N-oxide or 1-hydroxy-2-pyridinethione and VOSO4, and characterized by UV, IR and EPR spectra, magnetic susceptibility and partition coefficient. Based on the higher in vitro insulin-mimetic activity of VO(OPT) (IC50 = 0.19 mM) than that of VOSO4 (IC50 = 0.9 mM), the complex was found to be a potent agent for treating insulin-dependent diabetes mellitus in rats when given by daily intravenous injection or oral administration.
Synthesis and Structure of [2]Catenated tertiary Octamide and Octamine
Authors: Watanabe Nobuhiro , Furusho Yoshio , Kihara Nobuhiro , Takata Toshikazu , Kinbara Kazushi , Saigo Kazuhiko
Published: September 2003

Treatment of [2]catenated sec. octamide (1) with methyl iodide under an alkaline condition gave the corresponding N-methylated tert. octamide (2) which was reduced to [2]catenated tert. octamine (3). The structures of 2 and 3 were studied by X-ray crystal structure and 1H NMR analyses.
Acid Strength of Sulfated Zirconia Inferred from Catalytic Isobutane Conversion
Authors: Fraenkel Dan
Published: September 2003

The kinetics of the catalytic conversion of isobutane under gas-phase fixed-bed flow conditions over sulfated zirconia (SZ), when compared with those of other strong solid acids of known acidity, suggests that SZ may be a very strong solid superacid; this conclusion disagrees with recent reports claiming that SZ is not a superacid, and supports older claims, based on acidity tests with Hammett indicators, that SZ may have H0 of < −16.
High-power Low-Q RF ESR Resonator for Pulse Techniques
Authors: Yokoyama Hidekatsu , Sato Toshiyuki , Fukui Kouich , Ohya-Nishiguchi Hiroaki , Kamada Hitoshi
Published: September 2003

A new type RF ESR resonator for pulse techniques was developed. The resonator is an LC circuit that consists of a single turn coil (inner diameter, 45 mm) and ceramic capacitors. A two-turn coil-shaped polyethylene tube is located inside of the loop and an aqueous sodium chloride solution is perfused into the tube at a rate of 6 cm3/min. Its resonant frequency is approximately 300 MHz, with a Q of less than 70. Using this resonator, pulsed-longitudinally detected ESR measurements of a phantom (inner diameter, 20 mm) containing a triaryl methyl spin probe were performed. The Q value was sufficiently low for irradiation over wide frequency band in the pulsed radiowave where the pulse width was 200 ns. The apparatus can handle a sufficient high power (maximum, 100 W) adjusted according to the sample size.
Stereospecific Acceleration of Hydrolysis of p-Nitrophenyl d-Glycoside by α-Cyclodextrin
Authors: Ohe Takeru , Kajiwara Yuichi , Kida Toshiyuki , Zhang Wanbin , Nakatsuji Yohji , Ikeda Isao
Published: September 2003

The effects of cyclodextrin (CD) on alkaline hydrolysis of p-nitrophenyl α- and β-d-glycoside were investigated; α-CD selectively accelerates hydrolysis of p-nitrophenyl α-d-mannoside, β-d-glucoside, and β-d-galactoside in comparison to that of the corresponding β-d-mannoside, α-d-glucoside, and α-d-galactoside, respectively.
Zigzag Double-Strands Consisting of “Coordination-Gallery, [Ag3(NO3)3(Py2S)2•2H2O]”
Authors: Jung Ok-Sang , Park Sung Ho , Park Chul Hee , Park Jong Ku
Published: September 2003

Zigzag silver(I) single-strands connected by 4,4′-dipyridyl sulfide are bridged via weak π-π and AgI-AgI interactions to generate subtle double-strands that exhibit the most plentiful and characteristic coordination modes. The compound gives an intense and broad emission (λmax at 561 nm) which is yellow luminescence.
First Isolation and Characterization of an Electron Transfer Salt of a Tetracyanoquinodimethane with Porphyrinatomanganese(II) Having Novel cis-μ-Coordination Manner: A Molecule-based Magnet with a 2.3 K Tc
Authors: Sugiura Ken-ichi , Mikami Shinji , Johnson Mitchell T , Miller Joel S , Iwasaki Kentaro , Umishita Kazunori , Hino Shojun , Sakata Yoshiteru
Published: September 2003

An electron transfer salt comprised of 2,5-dimethyl-7,7,8,8-tetracyano-p-quinodimethane (DMTCNQ) with porphyrinatomanganese(II) was structurally and magnetically characterized. The [DMTCNQ]−• exhibits a novel cis-μ-coordination motif.
Protective Oxidation of a Layer Structured Manganese Titanate, RbXMnXTi2−XO4 (x = 0.75), in Acidic Solutions
Authors: Xu Zhang-Lin , Kunii Katsuyuki , Fukuoka Hiroshi , Yamanaka Shoji
Published: September 2003

A Iayer structured manganese titanate RbXMnXTi2−XO4 (x = 0.75) of the lepidoclocite type structure was oxidized with Ce4+ in sulfuric acid solutions. Although the titanate layer was dissolved into the acidic solutions without the oxidant, the layer showed high resistivity against the dissolution with the presence of Ce4+ ions, even in the same acidic conditions. A portion of the Rb ions were deintercalated corresponding to the amount of Mn3+ oxidized to Mn4+ in the manganese titanate layers.
A Novel Attempt to Control the Aggregation Number of Dendrons with a Saccharide
Authors: Ikeda Astushi , Numata Munenori , Shinkai Seiji
Published: September 2003

New dendrons containing a saccharide core were synthesized. In organic solvents these dendrons formed self-assembled particles due to the hydrogen-bonding interaction and the particle size decreased with the increase in the generation of dendrons. In this system the saccharide moieties provide a driving-force for aggregation whereas the dendritic moieties provide steric crowding for deaggregation. These two opposing effects balance with each other to control the particle size.
Generation and Reactions of an Overcrowded Diaryldilithiosilane
Authors: Tokitoh Norihiro , Hatano Ken , Sadahiro Tomoyuki , Okazaki Renji
Published: September 2003

Exhaustive reduction of dibromo(2,6-diisopropylphenyl){2,4,6-tris[bis(trimethylsilyl)methyl]phenyl}silane with excess amount of lithium naphthalenide (more than 4 molar amounts) in tetrahydrofuran at −78 °C gave the corresponding dilithiosilane, the effective formation of which was confirmed by the trapping experiments with a variety of electrophiles. The diaryldilithiosilane thus generated was found to be stable at −78 °C but undergo an intramolecular proton abstraction to give the lithium-migrated dilithiosilane.1
One-Pot Sequential Stereoselective Synthesis of Trisaccharide (Glcβ1-6Glcβ1-6Glc) by Promotion of Trityl Tetrakis(pentafluorophenyl)borate Catalyst
Authors: Mukaiyama Teruaki , Wakiyama Yoshinari , Miyazaki Kazuo , Takeuchi Kazuya
Published: September 2003

A one-pot synthesis of trisaccharides was successfully carried out by combination of two types of the trityl tetrakis(pentafluorophenyl)borate catalyzed stereoselective glycosylation reactions. Selective activation of a glycosyl phenyl carbonate in the presence of a thioglycoside allows two successive glycosyl coupling in one-pot manner to afford several protected trisaccharides, Glcβ1-6Glcβ1-6Glc, in good to high yields.