bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation and 1H NMR Spectra of Low Spin Ferric Porphyrin Radical Cations with Orientationally Fixed Imidazole Ligands
Authors: Nakamura Mikio , Kawasaki Yumiko 
Published: March 2006

Abstract
Chemical oxidation of tetradurylporphyrinatoiron(III) chloride followed by the addition of 2-methylimidazole at −78 °C gave the first example of the low spin ferric porphyrin radical cation with orienta ionally fixed imidazole ligands, [Fe(TDP•)(2-MeIm)2]2+. The degree of asymmetric spin distribution on the pyrrole β carbons in the radical cation was estimated to be close to that in the starting low spin complex, [Fe(TDP)(2-MeIm)2]+, which was ascribed to the orthogonality of porphyrin a2u with imidazole π orbitals.
Secretion of 112 kDa Phosphatase from the Cultured Suspension Cells of Liverworts
Authors: Nishizaki Ayako , Satake Atushi , Chen Li , Izumi Shunsuke , Hirata Toshifumi 
Published: March 2006

Abstract
A phosphatase (homodimer of 56 kDa subunits) having a hydrolyzing activity toward p-nitrophenyl dihydrogenphosphate and phosphohistone was found to be secreted from cultured suspension cells of Marchantia polymorpha into their culture medium. Such secretion of the phosphatase was promoted by addition of bornyl acetate into the culture medium.
Photochemical Desulfurization of a Sulfinato-S-Cobalt(III) Complex. Formation of an Organic Peroxide Complex
Authors: Akhter Farooque MD , Kojima Masaaki , Nakajima Kiyohiko , Yoshikawa Yuzo 
Published: March 2006

Abstract
The photolysis of trans(t-N,S)-[Co{S(O)2CH(CH3)COO-S,O}(tren)]+ (t-N = tertiary amine nitrogen; tren = tris(2-aminoethyl)amine) with visible light induced desufurization to yield an organic peroxide complex, trans(t-N,O(C))-[Co{OOCH-(CH3)COO-O,O}(tren)]+, (O(C)) = oxygen of carboxylate group) the structure of which was determined by X-ray analysis.
A Novel Diarylation Reaction of Alkynes by Using Aryltributylstannane in the Presence of Palladium Catalyst
Authors: Oda Hiroshi , Morishita Michiko , Fugami Keigo , Sano Hiroshi , Kosugi Masanori 
Published: March 2006

Abstract
Some alkynes were diarylated by aryltributylstannane 2 in the presence of palladium salt in moderate to good yield with high stereoselectivity. The reaction was catalytic in palladium using copper(II) chloride dihydrate as a reoxidant.
A Unique Copper(II)-Hydroxide Complex Derived from Copper(II)-Superoxide
Authors: Harata Manabu , Jitsukawa Koichiro , Masuda Hideki , Einaga Hisahiko 
Published: March 2006

Abstract
A unique Cu(II)-hydroxide complex, [Cu(tppa)(OH)]ClO4 (TPPA = tris[(6-(pivaloylamino)-2-pyridyl)methyl]amine), has been obtained from the [CuII(tppa)(O2−)]ClO4 complex in a methanol solution and characterized by the electronic absorption, ESR and ESI-MAS spectra and the X-ray diffraction method.
Effective Dispersion of Co in Co-Mo/Al2O3 Induced by High Pressure Sulfiding by Means of FT-IR Using NO as Surface Probe Molecule
Authors: Koizumi Naoto , Iijima Minoru , Kasahara Seiji , Yamada Muneyoshi 
Published: March 2006

Abstract
The surface structure of Co-Mo/Al2O3 sulfided in-situ at high pressure( ≤ 5 MPa) was characterized by FT-IR/DRA method using NO as a probe molecule. The ratio of the band intensity of NO adsorbed on Co site to that of Mo site increased, when Co-Mo/Al2O3 was sulfided at the pressure above 1.1 MPa. Combining the results with those found on catalysts varying the Co/Mo molar ratio, it was suggested that Co site is more effectively dispersed on Mo site by higher pressure sulfiding.
A Novel Synthesis of Dialkyl Carbonates from Carbon Dioxide, Alcohols, and tert-Amines Mediated by Acetylene
Authors: Sasaki Yoshiyuki 
Published: March 2006

Abstract
A novel acetylene-mediated reaction of carbon dioxide with alcohols and tert-amines leads to effective formations of dialkyl carbonates and alkyl N,N-dialkylcarbamates without catalyst.
Photoreactions of Silyliron(II) Complexes Cp′Fe(CO)2SiMe3 (Cp′ = η5-C5H5, η5-C5Me5) with Di-p-tolylgermane (p-Tol)2GeH2
Authors: El-Maradny Amr , Tobita Hiromi , Ogino Hiroshi 
Published: March 2006

Abstract
Photolysis of CpFe(CO)2SiMe3 (Cp = η5-C5H5) in the presence of (p-Tol)2GeH2 afforded a mixture of cis and trans isomers of diiron complexes Cp2Fe2(CO)2(μ-CO){μ-Ge(p-Tol)2} and Cp2Fe2(CO)2{μ-Ge(p-Tol)2}2. The Photostationary state with cis : trans = 85 : 15 was attained by the photolysis of either cis or trans isomer of the latter complex. In contrast, photoreaction of Cp*Fe(CO)2SiMe3 (Cp* = η5-C5Me5) with (p-Tol)2GeH2 gave a monoiron complex Cp*Fe(CO)2GeH(p-Tol)2.
Epoxidation of Vitamin K3 by Electrochemically Generated Hypohalogen Acids
Authors: Takano Nobuhiro , Ogata Manabu , Takeno Noboru 
Published: March 2006

Abstract
The epoxidation of vitamin K3 was carried out using electrochemically generated hypohalogen acids HOX in organic solvent-water containing halide salts. The electroepoxidation in CH3CN-H2O-NaI system led to the formation of the epoxide in good yield.
Stereospecific 4-Hydrogen Transfer in the Asymmetric Reduction Using (SS)-3-(p-Tolylsulfinyl)-1,4-dihydropyridines, NADH Model Compounds
Authors: Obika Satoshi , Nishiyama Toshihiko , Tatematsu Satoshi , Miyashita Kazuyuki , Imanishi Takeshi 
Published: March 2006

Abstract
In asymmetric reduction of ketones with (SS)-1-benzyl-3-(p-tolylsulfinyl)-1,4-dihydropyridine as a NADH model compound, a stereospecific transfer of the 4-hydrogen was experimentally proved by the use of the 2-methyl congener and the 4-deuterated derivatives.
Highly Efficient Synthetic Method of Optically Active 1,1,1-Trifluoro-2-alkanols by Enzymatic Hydrolysis of the Corresponding 2-Chloroacetates
Authors: Yonezawa Tetsuo , Sakamoto Yoshitaka , Nogawa Kouji , Yamazaki Takashi , Kitazume Tomoya 
Published: March 2006

Abstract
Enantioselective hydrolyses of 2-chloroacetates derived from racemic 1,1,1-trifluoro-2-alkanols were found to proceed very smoothly in the presence of a catalytic amount of lipase MY to yield the corresponding (R)-alcohols with high optical purity. In this procedure, Purification was easily carried out only by a simple distillation of the reaction mixture, enabling us to extend this reaction in a larger scale.
Reactivity of 1,1′-Spirobi(3H-2,1-benzoxatellurole)-3,3′-dione [10-Te-4(C2O2)] with Organic Phosphorus Reagents: The First Synthesis of a Tellurane with Two Carbon- and Two Sulfur-Tellurium Bonds, 1,1′-Spirobi(3H-2,1-benzothiatellurole)-3,3′-dione [10-Te-4(C2S2)]
Authors: Takaguchi Yutaka , Furukawa Naomichi 
Published: March 2006

Abstract
A new spirotellurane, 1,1′-spirobi (3H -2,1-benzothiatellurole)-3,3′-dione [10-Te-4(C2S2)] (2), having two sulfur atoms as the apical ligands and two carbon atoms as the equatorial ligands was obtained by the reaction of the spirotellurane 1 with Lawesson’s reagent. The treatment of 2 with aqueous NaOH gave an unsymmetrical spirotellurane 4. The telluranes 1 and 2 underwent ring-opening reactions on treatment with P(NEt2)3 to afford the telluride 6.
Diastereotropic Phenomena for the Appearance of SmCA* Phase in α-Trifluoromethyl-β-methyl-substituted Liquid Crystalline Molecules
Authors: Mikami Koichi , Yajima Tomoko , Terada Masahiro , Kawauchi Susumu , Suzuki Yoshiichi , Kobayashi Ichiro 
Published: March 2006

Abstract
Anti-ferroelectric (SmCA*) and ferroelectric (SmC*) phases of α-trifluoromethyl-β-methyl-substituted liquid crystalline (LC) molecules, synthesized highly diastereo- and enantioselectively through our chiral titanium complex-catalyzed fluoral-ene reaction, were determined by thermal analysis and electro-optic measurements. Phase transitions were thus found to be critically dependent on the diastereomeric excess (diastereotropic) for ul (Rα, Sβ)-diastereomers of the LC molecules.
Quantitative Detection of Protein Binding onto DNA by Using a Quartz-Crystal Microbalance
Authors: Niikura Kenichi , Nagata Kyosuke , Okahata Yoshio 
Published: March 2006

Abstract
Selective binding process of proteins to DNA strands immobilized on an Au electrode of a quartz-crystal microbalance (QCM) was observed in situ from frequency decrease (mass increase). The binding kinetics of sequence specific binding of NFI to DNA containing its recognition site were compared with those of non-specific binding of histone f3.
Preparation of One Structural Isomer of Tetra-substituted Phthalocyanine, 1,8,15,22-Tetra(3′-pentoxy)phthalocyanine, and a Crystal Structure of Its Nickel(II) Complex
Authors: Kasuga Kuninobu , Kawashima Makoto , Asano Kenichiro , Sugimori Tamotsu , Abe Kohji , Kikkawa Takahiko , Fujiwara Takaji 
Published: March 2006

Abstract
The selective preparation of 1,8,15,22-tetra(3′-pentoxy)phthalocyanine from 3-(3′-pentoxy)-1,2-dicyanobenzene was carried out. Its nickel(II) complex was obtained from the phthalocyanine and nickel(II) chloride, and a crystal structure of the complex was determined by an X-ray analysis.
RNA Hydrolysis by the Combination of the Lanthanum(III) Ion and Hydrogen Peroxide
Authors: Komiyama Makoto , Kamitani Jun , Sumaoka Jun , Asanuma Hiroyuki 
Published: March 2006

Abstract
Diribonucleotides are efficiently hydrolyzed by the combination of the lanthanum(III) ion and hydrogen peroxide at pH 7.2 and 30 °C. The rate constant for the hydrolysis of adenylyl(3′-5′)adenosine by the mixture of La(ClO4)3 (10 mmol dm−3) and H2O2 (100 mmol dm−3) is 7.7 × 10−2 min−1 (half-life 9 min), corresponding to a 460 fold cooperative promotion of the catalysis.
Single Crystal X-Ray Analyses of a Series of Hexamethylphosphoramide-Coordinated Complexes of Rare Earth Triflates: Existence of Tetrad Effects in the Coordinate Bonds
Authors: Imamoto Tsuneo , Nishiura Masayoshi , Yamanoi Yoshinori , Tsuruta Hideyuki , Yamaguchi Kentaro 
Published: March 2006

Abstract
The molecular structures of [M(OTf)2(hmpa)4]OTf·CHCl3(OTf = OSO2CF3; M = Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), [Sc(OTf)2(hmpa)4]OTf, and [La(η2-OTf)(OTf)(hmpa)4]OTf·CHCl3 were accurately determined by single crystal X-ray analyses. Tetrad effects are manifested in the series of the coordinate bond lengths.
Spectral Evidence and Kinetics for Formation of the Sitting-Atop Complex of Copper(II) Ion with 5,10,15,20-Tetraphenylporphyrin in Acetonitrile
Authors: Inada Yasuhiro , Sugimoto Yumi , Nakano Yuko , Funahashi Shigenobu 
Published: March 2006

Abstract
The kinetic parameters for the formation of the sitting-atop (SAT) complex of the copper(II) ion with 5,10,15,20-tetraphenylporphyrin (H2tpp) were directly determined in acetonitrile. The large ΔH≠ and ΔS≠ values imply that deformation of the porphyrin ring is required during the activation process. In the SAT complex, the protons bound to the pyrrole nitrogens remain on the nitrogens and by the addition of a base such as pyridine, they are abstracted to form the Cu(tpp) complex, in which the copper(II) ion is incorporated into the porphyrin core.
A Facile Synthesis of Angularly-Fused 3,4,4a,10b-Tetrahydro-2H,5H-pyrano[3,2-c][1]benzopyrans by the One-pot Condensation between Salicylaldehydes and Unsaturated Alcohols
Authors: Inoue Seiichi , Asami Masatoshi , Honda Kiyoshi , Miyazaki Hidekazu 
Published: March 2006

Abstract
Salicylaldehydes reacted with 5-methyl-4-hexen-1-ol (4a) or 6-methyl-5-hepten-2-ol (4b) in benzene in the presence of trimethyl orthoformate and a catalytic amount of p-toluenesulfonic acid at rt to give angularly-fused trans-5,5-dimethyl-3,4,4a,10b-tetrahydro-2H,5H-pyrano[3,2-c][1]benzopyrans (6) in high yields with complete stereoselectivity.
Conversion Dependence of Enantioselective Hydrogenation of (E)-α-Phenylcinnamic Acid on Cinchonidine-Modified Pd/TiO2 Catalyst
Authors: Nitta Yuriko , Kobiro Kazuya 
Published: March 2006

Abstract
The enantioselectivity of a cinchonidine-modified Pd/TiO2 catalyst varied with the extent of conversion in the hydrogenation of (E)-α-phenylcinnamic acid. The incremental enantioselectivity reached a maximum at an early stage of the reaction. Under optimized reaction conditions, optical yields of up to 72 %e.e. of (S)-(+)-2,3-diphenylpropionic acid were obtained at 100 % conversion.
Open and Closed Conformations of Binuclear Cu(II) Complexes with a Bimacrocyclic Ligand Linked by a Tetramethylene Chain
Authors: Mochizuki Katsura , Miyashita Sen 
Published: March 2006

Abstract
A binuclear Cu(II) complex with a bimacrocyclic ligand, [Cu2(OH2)2L](ClO4)4·4H2O (L: 7,7′-tetramethylene-bis[2,12-dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),2,11,13,15-pentaene]) has the open conformation, in which the tetramethylene chain is staircase-like so that two macrocycles are as far apart as possible. [Cu2Cu2L](ClO4)2·H2O adopts the closed conformation, in which the tetramethylene chain is folded so that the two macrocycles face each other.
The Effect of Terminal Group on Electron-Transfer Kinetics of Azobenzene Self-Assembled Monolayers on Gold
Authors: Yu Hua-Zhong , Wang Yong-Qiang , Cai Sheng-Min , Liu Zhong-Fan 
Published: March 2006

Abstract
The apparent electron-transfer rates of a new class azobenzene self-assembled monolayers on gold decreased significantly with increasing chainlength of terminal groups. With terminal groups longer than three carbon atoms, no distinguish feature for faradic response was observed.
Iron(III) Complex of a Trihydroxamate Ligand with an Ala-Ala-(HO)Gly-Ala Sequence as a Model for Ferrioxamines. Formation of Well-Defined Peptide Loop Structure
Authors: Akiyama Masayasu , Katoh Akira , Mutsui Yuriko , Watanabe Yuichi , Umemoto Kimiko 
Published: March 2006

Abstract
A dodecapeptide trihydroxamate ligand forms a well-defined chiral complex with iron(III) in which this small linear peptide assumes a unique loop conformation, uncommon to protein structures. The complex exhibits siderophore activity for a test microorganism.
Oxidative Dehydrogenation of Glycolic Acid to Glyoxylic Acid over Fe-P-O Catalyst
Authors: Ai Mamoru , Ohdan Kyoji 
Published: March 2006

Abstract
Glyoxylic acid was obtained by a vapor phase oxidative dehydrogenation of glycolic acid over an iron phosphate catalyst with a P/Fe atomic ratio of 1.2. The one-pass yield reached 59 mol% at the glycolic acid conversion of 78%; the selectivity of 76 mol%.
Distribution of Zinc Tetraphenylporphine in Single Melamine-Resin/Toluene Microcapsules Studied by Laser Trapping-Microspectroscopy
Authors: Kim Haeng-Boo , Yoshida Shuri , Miura Atsushi , Kitamura Noboru 
Published: March 2006

Abstract
Absorption microspectroscopy has been conducted to study chemical properties of single melamine-resin microcapsules containing a zinc tetraphenylporphine (ZnTPP)/toluene solution. Although absorbance of ZnTPP in the capsule increased with increasing the capsule diameter, its tendency was much smaller than that expected from a homogeneous distribution of ZnTPP in the inner toluene solution. The results were discussed in terms of a distribution of ZnTPP in both the melamine-resin and toluene phases.
57Fe Mössbauer Spectroscopic Study on the Dynamics of Ferrocene Enclathrated in Deoxycholic Acid
Authors: Nakashima Satoru , Nakashita Mitsuyori , Sakai Hiroshi 
Published: March 2006

Abstract
The molecular motion of ferrocene molecules enclathrated in deoxycholic acid was investigated by means of 57Fe Mössbauer spectroscopy, and it was newly suggested that an anisotropic vibration of the ferrocene molecule is coupled with the rotation above 280 K.
Stereoselective Route to the Highly Oxidated Sidechain Moiety of Terpentecin and Related Antibiotics
Authors: Takao Ken-ichi , Aiba Yasuyuki , Ito Hisanaka , Kobayashi Susumu 
Published: March 2006

Abstract
Highly oxidated sidechain moiety of antitumor terpentecin and related antibiotics is prepared in a stereoselective manner from diacetone glucose through furanoside intermediates.
Formation of a Tetranuclear High–Spin Iron(II,III,II,III) Mixed Valence Complex
Authors: Sugimoto Hideki , Hayashi Yoshihito , Koshi Chikako , Fujinami Shuhei , Suzuki Masatatsu , Maeda Yonezou , Uehara Akira 
Published: March 2006

Abstract
A class II mixed valent Fe4(II,III,II,III) complex [Fe4(Me4-tpdp)2(μ-F)2(OH)2(H2O)2](BF4)4 was synthesized, where HMe4-tpdp is N,N,N′,N′-tetrakis[2-(6-methylpyridyl)methyl]-1,3-diamino-2-propanol. The crystal structure shows that the complex cation consists of two alkoxo-bridged dinuclear units which are connected by two fluoro bridges to form a bilayered structure (a box structure).
Oxidative Generation of 2-(Trifluoromethyl)- and 2-(Chlorodifluoromethyl)allylic Cations and Its Synthetic Application
Authors: Fuchigami Toshio , Yamamoto Kayoko 
Published: March 2006

Abstract
Oxidative generation of allylic cations having strong electron-withdrawing CF3 and CF2Cl groups from 2-(trifluoromethyl)- and 2-(chlorodifluoromethyl)allylsilanes was successfully carried out for the first time. The generated cation was trapped with nucleophiles such as arenes and acetonitrile.
Preparation of Micro-Crystalline ZrO2 with Monoclinic Structure and Its Strong Acid and Base Sites
Authors: Nakabayashi Hirotoshi 
Published: March 2006

Abstract
The micro-crystalline ZrO2 with the monoclinic structure was prepared by the calcination at low temperature of the Zr-hydroxide obtained by the hydrolysis of Zr-alkoxide. Both the strong acid sites and the strong base sites were observed to be simultaneously generated on the monoclinic ZrO2 surface.
A Stereoregular Polyphenylacetylene Derivative Bearing an Amino Group as a Probe for Chirality Assignments of Acids by Circular Dichroism
Authors: Yashima Eiji , Maeda Yukio , Okamoto Yoshio 
Published: March 2006

Abstract
Cis-transoidal poly(4-(N,N-diisopropylaminomethyl)phenylacetylene) prepared by polymerization with [Rh(nbd)Cl]2 was found to exhibit an induced circular dichroism in the UV-visible region upon complexation with optically active acids probably due to a prevailing one-handed helix formation of the polymer, the sign of which reflects the absolute configuration of the acids.
1,4-Asymmetric Induction from Chiral δ-Oxygenated Allylic Tin Reagents
Authors: Nishigaichi Yutaka , Yoshikawa Miyuki , Takigawa Yasuyo , Takuwa Akio 
Published: March 2006

Abstract
A new type of asymmetric induction from allylic tin reagents is developed. A chiral allylic tin which has an oxygen substituent (ether or ester) at its δ-position successfully induces a new chirality in a 1,4-induction mode in the reaction with aldehydes via the transmetallation with SnCl4.
Catalytic Dehydrochlorination of 1, 2-Dichloroethane over Pyridine Deposited Pitch-Based Active Carbon Fiber
Authors: Sotowa Chiaki , Kawabuchi Yuji , Mochida Isao 
Published: March 2006

Abstract
Pitch-based active carbon fiber (pitch-ACF) modified by pyridine chemical vapor deposition (CVD) showed excellent catalytic activity for dehydrochlorination of 1, 2-dichloroethane (1, 2-DCE) into vinyl chloride (VC). Compared with polyacrylonitrile-based ACF (PAN-ACF), the present ACF of 2% weight increase by CVD showed long life over 300 h at 360 °C (conversion: ca. 20%; VC selectivity: 99.7%; contact time: 5.8 × 10−3).
Design and Synthesis of a Potential Endoglycosidase Inhibitor: Chemical Conversion of N,N′-Diacetylchitobiose into Novel Pseudodisaccharide Containing a Fivemembered Cyclic N,N-Dimethylguanidine
Authors: Takahashi Shunya , Terayama Hiroyuki , Koshino Hiroyuki , Kuzuhara Hiroyoshi 
Published: March 2006

Abstract
(3aS,4R,5R,6R,6aS)-2-Dimethylamino-3a,5,6,6a-tetrahydro-4-hydroxy-6-hydroxymethyl-4H-cyclopentimidazole-5-yl 2-Acetamido-2-deoxy-β-d-glucopyranoside hydrochloride was designed as a potential inhibitor against endoglycosidases like lysozyme and chitinase, and was synthesized from N,N′-diacetylchitobiose by a series of reactions including radical cyclization of oxime ethers and cyclic guanidine-formation.
Promoting Effects of Carbon Dioxide on Dehydrogenation of Propane over a SiO2-supported Cr2O3 Catalyst
Authors: Takahara Isao , Saito Masahiro 
Published: March 2006

Abstract
The effects of carbon dioxide in the dehydrogenation of C3H8 to produce C3H6 were investigated over several Cr2O3 catalysts supported on Al2O3, active carbon and SiO2. Carbon dioxide exerted promoting effects only on SiO2-supported Cr2O3 catalyst. The promoting effects of carbon dioxide over a Cr2O3/SiO2 catalyst were to enhance the yield of C3H6 and to suppress the catalyst deactivation.
Determination of Memory Life of a Molecular Hysteresis Molecule by Thin Layer CV
Authors: Tomita Atsuko , Sano Mitsuru 
Published: March 2006

Abstract
Thin layer cyclic voltammograms have been measured for (1,5-dithiacyclooctane 1-oxide) bis(pentaammineruthenium(II)) in acetone. The rates of the interconversions of the two intermediate species are determined to be 2 × 10−4 s−1 and 4.4 × 10−4 s−1 by digital simulations to the thin layer voltammograms. The half life of the memory in the molecule is 1600 s.
Cationic Polymerization of Styrene with N-Benzyl Pyridinium Salt. Isolation of Polymeric Cationic Species and Its Application to Block Copolymer Synthesis
Authors: Lee Sang-Bong , Lee Kyu-Wan , Takata Toshikazu , Endo Takeshi 
Published: March 2006

Abstract
A polymeric cationic species (III) could be isolated in the cationic polymerization of styrene with an N-benzyl pyridinium salt (MBCP) by adding the corresponding pyridine (OCP). III is considered to be a terminated end which is active enough to initiate the cationic polymerization since it has still an N-benzyl pyridinium salt structure. Therefore, III could initiate the cationic polymerization of epoxides to give the block copolymers of styrene and epoxides.
A New Stereocontrolled Route to (−)-Shikimic Acid
Authors: Kamikubo Takashi , Ogasawara Kunio 
Published: March 2006

Abstract
A new stereocontrolled route to (−)-shikimic acid, the component of the fruit of shikimi tree, Illicium religiosum, and the key biogenetic precursor of a variety of aromatic natural products, has been developed using the chiral 2,5-cyclohexadienol synthon.
Ion-exchange Reaction of Rubidium Ion in Rb8Nb22O59
Authors: Kumada Nobuhiro , Takagi Masakazu , Kinomura Nobukazu 
Published: March 2006

Abstract
Rubidium ion in Rb8Nb22O59 with a tunnel structure was ion-exchanged with alkaline ions and proton. The ion-exchange with proton was almost complete to yield H7.71Rb0.29Nb22O59·8.9H2O. The degree of ion-exchange with alkaline ions was 79.1%(Na+), 41.8%(K+) and 2.5%(Cs+), and the chemical compositions for the ion-exchanged compounds were Rb1.27Na6.33H0.40Nb22O59·6.1H2O, Rb3.06K3.34H1.60Nb22O59·5.1H2O and Rb6.22Cs0.20H1.58Nb22O59·1.9H2O. The ion-exchange of H7.71Rb0.29Nb22O59·8.9H2O with alkaline ions was also attempted.
Catalytic Stereoselective Synthesis of Pyrimidine 2-Deoxyribonucleosides
Authors: Mukaiyama Teruaki , Hirano Noriyuki , Nishida Minoru , Uchiro Hiromi 
Published: March 2006

Abstract
Highly stereoselective synthesis of β-d-deoxyribonucleosides from 1-O-acetyl-5-O-benzyl-2-deoxy-3-diethylthiocarbamoyl ribofuranoside (3) is performed by the reaction with silylated pyrimidine nucleobases in the presence of a catalytic amount of several Lewis acids.
Isolation of Two Conformationally Frozen Isomers of a Bridged Calix[6]arene
Authors: Saiki Toshiyuki , Okazaki Kei Goto, and Renji 
Published: March 2006

Abstract
Two conformationally frozen isomers of a 1,4-bridged calix[6]arene, one of which is a cone conformer while the other adopts a 1,2,3-alternate conformation, have been isolated by silica-gel chromatogarphy. The interconversion between them was not observed even after heating either of them at 120 °C.
Optional Formation of “Parallel or Antiparallel” β-Sheet-like Structures in (R)-(1-Naphthyl)glycyl-(R)-phenylglycine Crystals
Authors: Akazome Motohiro , Sumikawa Atsuko , Sonobe Ryo-ichi , Ogura Katsuyuki 
Published: March 2006

Abstract
(R)-(1-Naphthyl)glycyl-(R)-phenylglycine forms inclusion compounds with ethers (tetrahydrofuran and diethyl ether) or allylic alcohols (2-propen-1-ol and 2-methyl-2-propen-1-ol). X-ray crystallographic study showed that the dipeptide has the ability to optionally form “parallel or antiparallel” β-sheet-like structures by the choice of ethers or allylic alcohols, respectively, as the guest molecules.