bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystal Structures and Electronic Properties of Organic Conductors Based on AzaTCNQ
Authors: Urayama Hatsumi , Inabe Tamotsu , Mori Takehiko , Maruyama Yusei , Saito Gunzi 
Published: July 2006

Abstract
AzaTCNQ ((4-dicyanomethyl-1-pyridinio)dicyanomethanide) is employed as an organic acceptor to form new organic conductors with a TTF family such as TTF, TMTTF, TMTSF, HMTTF, and DBTTF. Among them, TMTTF and TMTSF give 2:1 single crystals and the latter affords the most conductive complex, showing a metallic characteristic down to 150 K. This can be observed by measuring the thermoelectric power and the ESR spectra. A crystal structure analysis indicates that only TMTSF molecules stack to form one-dimensional conduction pathways, while AzaTCNQ molecules are arranged side-by-side and oriented almost perpendicular to the donor molecules. There exists an orientational disorder of the nitrogen atom in the pyridine skeletone of an AzaTCNQ molecule, which may be associated with the weak temperature dependence of the electrical conductivity.
Basis Set Dependency of Energy Components in Hartree-Fock MO Theories. II. Conservability of Virial Ratio between Different Conformations
Authors: Ichikawa Hiroshi , Shigihara Atsushi 
Published: July 2006

Abstract
The authors examined 22 different basis sets in order to determine exactly how they reproduce the relative kinetic and potential energies. In an attempt to find the calculation error of such energy components, the virial relationship has been used between two conformations in which all bond lengths are optimized with respect to the total energy: i.e., the relationship, ΔV=−2ΔT, where ΔV and ΔT are the differences in the potential and kinetic energies. The degree of error was compared in terms of the relative virial error ((ΔE+ΔT)⁄ΔE) to the difference in the total energies (ΔE). STO-NG was found to give a large amount of casual error, up to 500% to ΔE. Such an error could be dramatically improved by using a split-valence method. It should be noted that 4-31G and 6-31G methods resulted in a small amount of error and that the inclusion of polarization functions does not always improve the amount of error.
The Entropy of Solution of Alkanes Measured by Gas-Liquid Chromatography and Interpreted by Means of Scaled Particle Theory
Authors: Fujiwara Hideaki , Ohtaku Ikuji , Takagi Tatsuya , Murata Saburo , Sasaki Yoshio 
Published: July 2006

Abstract
The entropy of solution was measured by gas-liquid chromatography for the alkanes from pentane to decane in dibutyl phthalate solution. The results are discussed in relation to the Wertz-type equation, which correlates the entropy of solution with the thermodynamic third-law entropy of the solute, and to the scaled particle theory. A scaled particle treatment assuming non-spheres(spherocylinders) is shown to give improved results and to be promising in reproducing the experimental values of the entropy of solution, whereas the same treatment of spheres failed to explain the trend in the experimental values.
Calorimetric and Dielectric Studies of Phase Transitions in Rubidium Nitrite
Authors: Moriya Keiichi , Matsuo Takasuke , Suga Hiroshi 
Published: July 2006

Abstract
The heat capacities of RbNO2 crystal have been measured between 15 and 330 K. Two phase transitions were found at (264.04±0.06) K and (83.8±0.2) K. The enthalpy and entropy of transition are (9310±450) J mol−1 and (35.9±1.8) JK−1 mol−1 for the former and (48±5) J mol−1 and (0.58±0.05) JK−1 mol−1 for the latter. The entropy of the high temperature transition was interpreted in terms of the orientational disorder of the NO2− ion. The dielectric constant increased from 6 to 10 as the transition temperature 264.04 K was traversed from below, indicating the increased motional freedom of the polar anion in the high temperature phase.
Role of Ti–O–Zr Bonding in TiO2–ZrO2 Catalyst for Dehydrogenation of Ethylbenzene
Authors: Hirashima Yutaka , Nishiwaki Katsuhiko , Miyakoshi Akihiko , Tsuiki Hideyasu , Ueno Akifumi , Nakabayashi Hirotoshi 
Published: July 2006

Abstract
A relationship between acid amounts over TiO2–ZrO2 catalysts and their activities for nonoxidative dehydrogenation of ethyl benzene to styrene was examined. The catalysts were prepared by two different methods; one is simultaneous hydrolysis of Ti and Zr mixed alkoxides solution and the other is physical mixing of pure TiO2 and ZrO2. The former consists of fine TiO2 and ZrO2 particles and is expected a lot of Ti–O–Zr bonding between the fine particles, while the latter is composed of large particles and less amounts of Ti–O–Zr bonding might be expected. Although the Ti–O–Zr bonding has been considered to generate a new acid site and to enhance the rate of dehydrogenation of ethylbenzene, the acid amounts and the rates observed on unit surface areas of both catalysts were not significantly different. On the basis of these results, the role of Ti–O–Zr bondig in TiO2–ZrO2 catalyst for dehydrogenation of ethylbenzene is discussed.
Synthesis of Naphthoquinone Derivatives. XIII. Reaction of 2,3-Dihydro-2-thioxo-1H-naphth[2,3-d]imidazole-4,9-dione with Dimethyl Acetylenedicarboxylate
Authors: Nakamori Tateo , Saito Toshiyuki , Kasai Toshiyasu 
Published: July 2006

Abstract
Tetracyclic compounds with a thiazolidinone or thiazinone ring fused to 1H-naphth[2,3-d]imidazole-4,9-dione were synthesized. Dimethyl 2-(4,9-dioxo-4,9-dihydronaphth[2,3-d]imidazol-2-ylthio)fumarate (3) was obtained by a reaction of 2,3-dihydro-2-thioxo-1H-naphth[2,3-d]imidazole-4,9-dione with dimethyl acetylenedicarboxylate in methanol. A ring-closure reaction of 3 in acetic anhydride was found to give selectively methyl (3,5,10-trioxo-2,3,5,10-tetrahydronaphth[2′,3′ : 4,5]imidazo[2,1-b]thiazol-2-ylidene)acetate, while, the cyclization of 3 in polyphosphoric acid afforded methyl 4,6,11-trioxo-6,11-dihydro-4H-naphth[2′,3′ : 4,5]imidazo[2,1-b]thiazine-2-carboxylate.
Synthesis of (S)- and (R)-3-Hydroxy-4-butanolide and (2S,4S)-, (2R,4S)-, (2S,4R)-, and (2R,4R)-2-Hydroxy-4-hydroxymethyl-4-butanolide and Their Satiety and Hunger Modulating Activities
Authors: Uchikawa Osamu , Okukado Nobuhisa , Sakata Toshiie , Arase Koichi , Terada Kenji 
Published: July 2006

Abstract
Two endogenous γ-lactones, 3-hydroxy-4-butanolide (1) and 2-hydroxy-4-hydroxymethyl-4-butanolide (2) have been identified as substances that enhance, respectively, satiety and hunger by their effects on the feeding behavior and the central neurons of rats. To determine the stereochemistry of the physiologically active isomers, all the stereoisomers of these two lactones were synthesized and their effects on the feeding behavior and humoral factors were assessed by infusion into the rat third cerebroventricle. Among four isomers, (2S,4S)-2-hydroxy-4-hydroxymethyl-4-butanolide (2a) was most effective in elicitating the feeding and caused potent hypoglycemia with hyperinsulinemia. (S)-3-Hydroxy-4-butanolide (1a) suppressed the food intake more potently than the antipode and caused humoral responses reciprocal to those of 2a. From these facts, it was concluded that 1a and 2a are physiologically active forms for conveying intrinsic signals of satiety and hunger to neurons in the hypothalamus.
Studies on Synthetic Ionophores. VI. Synthesis of Polyether Carboxylic Acids and Their Use as Carriers for Alkali Metal Ion Transport through Liquid Membrane
Authors: Yamaguchi Kazuo , Negi Shigeto , Kozakai Shohei , Nagano Roichi , Kuboniwa Hitoshi , Hirao Akira , Nakahama Seiichi , Yamazaki Noboru 
Published: July 2006

Abstract
ω-Hydroxy carboxylic acids (3, 5, 6, 7, 10, 12, 14, 17, 18, 20, and 22) bearing 2–6 ether oxygens and aromatic rings with or without a tetrahydrofuran ring and the ω-methoxy and ω-benzyloxy derivatives of 5 (8 and 9) were synthesized. These were employed as carriers for active and competitive transport of alkali metal ions through liquid membrane as well as for extraction of alkali metal ions to organic layers. Effect of hydrophobic group of aromatic and tetrahydrofuran rings, number of ether oxygens, and terminal hydroxyl group of the ionophores on the ion transport ability and selectivity were investigated. The hydrophobic groups increased total amount of transported ions as well as partition coefficients. The ionophore, 5, which contains five ether oxygens, two aromatic rings, and o-toluic acid moiety transported K+ selectively over Na+ and Li+ through 1,2-dichloroethane being consistent with the extraction experiments. The m- and p-substituted isomers, 6 and 7, exhibited no transport ability through 1,2-dichloroethane. The ω-alkoxy derivatives of 5 (8 and 9) exhibited less selectivity for K+ through 1,2-dichloroethane than 5 did. Through 1-hexanol, the ionophores, 5–9, including linoleic acid with no ether linkage transported alkali metal ions. The ionophores (3, 12, 20, and 22) containing 2–4 ether oxygens did not exhibit high transport ability.
Determining Factors for the Product Para/Ortho Ratio and Reaction Rate in the Formation of (Hydroxymethyl)phenols from Phenol and Formaldehyde
Authors: Komiyama Makoto 
Published: July 2006

Abstract
Formations of 2- and 4-(hydroxymethyl)phenols from phenol and formaldehyde in aqueous alkaline solutions were kinetically investigated by the use of HPLC. The para/ortho ratio for the products sigmoidally increased with increasing concentration of sodium hydroxide, whereas the total yield of the (hydroxymethyl)phenols showed a steep maximum at the charged molar ratio unity of sodium hydroxide to phenol. Use of lithium hydroxide and potassium hydroxide, in place of sodium hydroxide, as alkaline catalysts results in almost the same para/ortho ratios. The addition of potassium chloride and magnesium sulfate decreased both the para/ortho ratio and the yield. These results indicate that the reactions proceed via an electrophilic attack of formaldehyde, which is free from the adduct formation with hydroxide ion, at phenolate ion. Electrostatic interactions between the phenoxide oxygen atom of the phenol and the incoming hydroxymethyl residues in the transition state exhibit a predominant role in the determination of the para/ortho ratio.
Syntheses and Cytotoxicity of the AB-, C-, and BC-Ring Systems of Sesbanimides
Authors: Matsuda Fuyuhiko , Ohsaki Masako , Yamada Kaoru , Terashima Shiro 
Published: July 2006

Abstract
Preparation of some AB-ring systems 5 and 8 of sesbanimides 1 and 2, potent antitumor alkaloids, were performed starting from the synthetic intermediates of our first total synthesis of 1 and 2. The C-ring systems 14a–d were synthesized by applying the previously explored novel Reformatsky reaction to various aldehydes. The optically active BC-ring systems 20 and 21 having the same absolute configurations as those of 1 and 2, were derived from (−)-2,4-O-methylene d-sorbitol (15) as the B-ring synthon. Since all of these compounds 5, 8, 14a–d, 20, and 21 and the previously synthesized AB-ring system 3 showed no significant in vitro cytotoxicity against P388 murine leukemia, its appeared evident that 1 and 2 exhibit their notable antitumor activity owing to cooperation of the A- and C-rings.
Ultrasonic Investigation on the Structure of Aqueous Solution of 2-Butanone
Authors: Ramanjappa T , Rajagopal E 
Published: July 2006

Abstract
The effect of 2-butanone on the temperature corresponding to adiabatic compressibility minimum (TACM), sound velocity maximum (TSVM) and specific acoustic impedance maximum (TSAIM) of pure water has been studied by experimentally determining the sound velocity and density of aqueous solution at different concentrations over a temperature range 34–70.5 °C. The structural contribution to the shift in TACM, TSVM, and TSAIM has been evaluated. The shift is positive throughout the concentration range studied and indicates that 2-butanone is hydrophobic in nature.
Ion-Exchange Properties of Niobium(V) Materials. II. Synthesis and Characterization of Crystalline Niobium(V) Phosphate
Authors: Qureshi Mohsin , Gupta Jai Prakash , Khan Hina , Ahmad Anees 
Published: July 2006

Abstract
An attempt has been made to synthesize and characterize the crystalline niobium(V) phosphate. The characterization was done on the basis of pH titration, X-ray, XPS, TGA, DSC, and IR studies. It is an ion exchange material which shows about 20% higher chemical stability over the amorphous niobium(V) phosphate. It was found to have a pseudocubical unit cell structure with a0(H)=10.244 Å and a stiff three dimensional zeolytic structure. The empirical formula of the compound was obtained as Nb2O5·1.5 P2O5·7.5 H2O. The proposed chemical formula is (NbO)2(HPO4)3·6H2O (d110=7.23 Å). The exchanger is monofunctional in nature having the maximum exchange capacity of 4.6 meq g−1 for potassium ion at pH 8.5
Photoresponsive Peptide and Polypeptide Systems. VI. Reversible Solubility Change of Azo Aromatic Lysine
Authors: Yamamoto Hiroyuki , Nishida Ayako 
Published: July 2006

Abstract
The reversible solubility change of azo aromatic lysines due to the trans–cis photoconversion of azo moieties was studied. On irradiation at different wavelengths, azo aromatic lysines are soluble under ultraviolet light (cis) and precipitate under visible light (trans). The dipole moments of the solvents used are considered to play a role in the solubility change.
X-Ray Structure Determination and NMR Characterization of Some Fused Heterocycles with a 1,3,5-Triazine-2,4(1H,3H)-dione Ring. Reaction of 2-Amino-4(3H)-pyrimidinone with Chloroformyl Isocyanate
Authors: Sawada Masami , Tanaka Takanori , Furukawa Yoshiro , Toda Tomoki , Takai Yoshio , Hanafusa Terukiyo 
Published: July 2006

Abstract
The reaction product a of 2-amino-4(3H)-pyrimidinone with chloroformyl isocyanate was methylated and the two resulting products were determined as 4 (for the major product) and 5 (for the minor one) by X-ray crystal structure analyses. In a DMSO solution of a, the 2a tautomer was shown to be predominant by 13C NMR analysis.
The Synthesis of a Heavy-Atom Derivative of Gramicidin S (GS), [d-Phe(4-Br)4,4′]-GS, by a Novel Method
Authors: Aimoto Saburo 
Published: July 2006

Abstract
A new approach for the preparation of cyclic peptides was successfully applied to the synthesis of cyclo(–Val–Orn–Leu–d–Phe(4-Br)–Pro–Val–Orn–Leu–d–Phe (4-Br)–Pro–) ([d–Phe(4-Br)4,4′]-GS). [d–Phe(4-Br)4,4′]–GS showing antibacterial activity was obtained as crystals.
Syntheses and NMR Spectroscopic Studies on the Conformations of 1-[1-(2-Aralkyloxy- and 2-Acyloxyphenyl)vinyl]-1H-Imidazoles
Authors: Yamamoto Kazuko , Hamada Yoshiki , Takeuchi Isao , Suezawa Hiroko , Hirota Minoru 
Published: July 2006

Abstract
The title compounds were synthesized from 2-[1-(1-imidazolyl)vinyl]phenol and their conformations were discussed on the basis of their 1H and 13C NMR spectra.
Synthetic Photochemistry. XLI. Photorearrangement of 5-Alykyl-1-hydroxy-8-oxabicyclo[3.2.1]octa-3,6-dien-2-ones to 2-Alkyl-3-oxatricyclo[3.3.0.02,8]octane-4,6-diones
Authors: Mori Akira , Kasai Seishi , Takeshita Hitoshi 
Published: July 2006

Abstract
The irradiations of 5-alkyl-1-hydroxy-8-oxabicyclo[3.2.1]octa-3,6-dien-2-ones, either in benzene or methanol by means of a high-pressure mercury lamp produced 2-alkyl-3-oxatricyclo[3.3.0.02,8]octane-4,6-diones. Although the intermediate ketenes could be detected by low temperature NMR, no adduct was formed in protic solvents.
One Pot Synthesis of Dinuclear Tungsten(V) Compounds Containing [W2XY(μ-S)2]2+ (X=O,S; Y=O,S) Cores by Thermally Induced Internal Electron-Transfer Processes
Authors: Ansari Mohammad A , Chandrasekaran Jayanthi , Sarkar Sabyasachi 
Published: July 2006

Abstract
New synthetic methods for the preparation of dimeric tungsten(V) complexes are described containing the core [W2XY(μ-S)2]2+ (X=O,S; Y=O,S). The synthesized complexes have been characterized by a variety of spectroscopic techniques. [W2OS(μ-S)2(S2CNEt2)2] has been found to react with cyanide to give [W2O2(μ-S)2(S2CNEt2)2].
Synthesis and Properties of Three Sulfur-Containing Porphyrins, One Water-Soluble
Authors: Datta-Gupta Nirmalendu , Malakar Debasis , Jenkins Celestine , Strange Cynthia 
Published: July 2006

Abstract
Three new porphyrins with sulfur functional groups, one of which is water-soluble, have been prepared. Their UV-visible absorption, fluorescence emission, and 1H NMR spectra as well as their copper(2+) insertion kinetics, pK3 values and first and second reduction potentials determined. For the water soluble porphyrin, its binding with human serum albumin (HSA) determined.
Mixed Colloidal Dispersions of Silica and Hematite
Authors: Esumi Kunio , Idogawa Hiroyuki , Meguro Kenjiro 
Published: July 2006

Abstract
The colloidal behavior of mixed dispersions containing hematite (diameter=138.9 nm) and silica (diameter=7.0 nm) has been studied by measuring the stability ratio, zeta potential, and particle size. When various particle numbers of silica were added to a constant particle number of hematite, different colloidal behavior was observed, depending on the pH. In a pH region where the two solids were oppositely charged, hematite particles showed a dispersion-coagulation-redispersion process with increasing particle number of silica, resulting in a coating layer of silica particles on the hematite surface. On the other hand, in a region where both solids were negative, the addition of silica enhanced the stability of the hematite.
Characterization of Monomeric and Polymeric (Octacyanophthalocyaninato)metals in Thin Films
Authors: Yanagi Hisao , Ueda Yasukiyo , Ashida Michio 
Published: July 2006

Abstract
Thin films were prepared by the reaction of 1,2,4,5-tetracyanobenzene with Ni, Co, Fe, Zn films at various temperatures. The films were characterized by infrared, UV/visible and photoelectron spectroscopy and analytical electron microscopy in comparison with films prepared on substrates of a KCl single crystal and a Cu film. The films produced on the metal films below 400 °C were composed of tentacle-like crystals growing from the surface and an amorphous layer condensed over the metal substrate. The tentacle-like crystals were soluble in concentrated sulfuric acid and were identified as intercalation compounds of (octacyanophthalocyaninato)metal with the respective metal atoms. The amorphous layers contained polymerization products with a polynitrile structure, which were insoluble in concentrated sulfuric acid. The films produced on the metal films at 450 °C were composed of a thick layer and had a very limited solubility in concentrated sulfuric acid. They were ascribed to metal complexes of polyphthalocyanines(poly-M(Pc)) and cross-linked polymers with structure elements such as polynitrile and triazine.
Molecular and Crystal Structure of the Bilayer-Forming Lipid-Model Amphiphile, Ditetradecyldimethylammonium Bromide Monohydrate
Authors: Okuyama Kenji , Iijima Naomi , Hirabayashi Kiyoshi , Kunitake Toyoki , Kusunoki Masami 
Published: July 2006

Abstract
The conformation and molecular packing of ditetradecyldimethylammonium bromide monohydrate (2C14N+2C1Br−·H2O), C30H62NBr·H2O, has been determined by the X-ray diffraction method. The crystals are triclinic with the space group P\bar1, Z=2, a=2.9827(9), b=0.7847(3), c=0.7480(3) nm, α=104.69(4), β=90.64(7), and γ=90.84(6)°. The structure was determined by direct methods and refined by the least-squares procedure: R=0.07 (Rw=0.07) for 3335 observed reflections. Two amphiphile molecules of the unit cell are related by centrosymmetry and pack tail to tail in a bilayer structure. The hydrocarbon chains tilt about 45° with respect to the bilayer normal. There are statistically four water molecules with half occupancies in a unit cell. Water molecules and bromide anions make hydrogen-bonding networks along the c-axis in the hydrophilic layer. The above molecular and crystal structure of 2C14N+2C1Br−·H2O was quite similar to those of 2C18N+2C1Br−·H2O.
The Spectrofluorometric Determination of Anthraquinone with Hydroxylamine in the Dimethyl Sulfoxide Medium Containing Sodium Methoxide and Methanol
Authors: Tachibana Masaki , Furusawa Motohisa 
Published: July 2006

Abstract
Anthraquinone reacts with hydroxylamine in the dimethyl sulfoxide (DMSO) medium containing sodium methoxide and methanol. Since the reaction product is fluorescent in the medium, this reaction can be used for the fluorometric determination of anthraquinone. A DMSO solution of a sample was mixed with a DMSO solution of hydroxylamine hydrochloride and a methanolic solution of sodium methoxide. The mixture was then allowed to stand for 20 min at 60 °C in a volumetric flask with a tightly fitting stopper. After cooling and dilution to the mark with DMSO, the fluorescence intensity of the solution was measured at 597 nm, with excitation at 494 nm. The intensity was stable for at least 2 h in the tightly stoppered flask. The determination limit of anthraquinone was 100 ng. By the application of this spectrofluorimetry, anthraquinone in 9,10-phenanthrenequinone could be successfully determined over the content range from 0.2 to 4%.
Reaction of 1,1,2,2-Tetrachloro-2,2aα,4α,8bα-tetrahydrocydobuta[c]quinolin-3(1H)-one with Nucleophiles; Reaction, Product Structure, and Mechanism
Authors: Nonoyama Shinji , Yonezawa Noriyuki , Saigo Kazuhiko , Hasegawa Masaki , Hirano Tsuneo 
Published: July 2006

Abstract
2a-Substituted dichlorodihydrocyclobuta[c]quinolin-3(4H)-one (3) and trichlorovinyl-2-quinolone (4) were obtained from the cross photocycloadduct of 2-quinolone and tetrachloroethylene. The position of the substituent on 3 was determined from the NOE volumes in the NOESY spectrum in comparison with the AM1 geometries. The reaction of the photoadduct (1) with a base or nucleophile, yielding 3 and/or 4, was interpreted to proceed via a cyclobutene intermediate formation followed by an SN2′ displacement or [2+2] cycloreversion.
Synthesis of 1,10-Disubstituted 1,4,7,10,13,16-Hexaazacyclooctadecanes and Their Extractability for Metal Cations
Authors: Takada Masayuki , Saigo Kazuhiko , Hirai Teruhisa , Ohchi Ikuro , Tajima Masayuki , Seno Manabu , Hasegawa Masaki 
Published: July 2006

Abstract
1,10-Disubstituted 1,4,7,10,13,16-hexaazacyclooctadecanes (hexaaza-18-crowns) having lipophilic groups were synthesized from 1,2-ethanediamine as a starting material. Cyclization of 3,6-ditosyl-3,6-diazaoctanedioyl dichloride and 3,6-ditosyl-3,6-diazaoctane-1,8-diamine under the high dilution conditions, followed by diborane reduction of the amide carbonyl, gave the macrocyclic precursor. A series of reactions, i.e., acylation, diborane reduction, and detosylation, afforded 1,10-disubstituted hexaaza-18-crowns. Their extractability for metal cations was examined by spectrophotometric analysis. They showed relatively high extractability for Ag+, Zn2+, and Cd2+.
Reaction of Rifamycins with Sodium Sulfinates
Authors: Taguchi Masahiro , Aikawa Norio , Yoshida Kenzaburo , Kitamura Mikiya , Tsukamoto Goro 
Published: July 2006

Abstract
The reaction of rifamycin S and the quinonic 3-(hydrazonomethyl)rifamycin derivatives with sodium sulfinates under neutral conditions were found to afford the hydroquinone-type 4-O-sulfonyl derivatives of rifamycin. 3-Amino-4-deoxo-4-iminorifamycin S also gave rise to the hydroquinone-type 4-deoxy-4-sulfonylamino derivatives of rifamycin when treated with sodium sulfinates. Under acidic conditions, rifamycin S and 3-bromorifamycin S produced the hydroquinone- and quinone-type 3-sulfonyl derivatives of rifamycin, respectively, by reactions with sodium sulfinates. Some of sodium salts of 4-O-sulfonylrifamycin SV derivatives afforded rifamycin S and sodium sulfinates and/or sodium sulfonates when heated in AcOEt.
Synthesis of α-Helices Having a Positively Charged Random Coil-Block on Either N- or C-Terminal
Authors: Takahashi Sho , Hibino Takeshi , Sawada Seiji 
Published: July 2006

Abstract
To study a charge-induced stabilization of α-helix, α-helical peptides having a positively charged random-coil block on either N- or C-terminal of the helix, and having a strictly defined length, (Ala)20(X)20Phe and (X)20(Ala)20Phe (X=Lys or Orn), were synthesized. Component dipeptides were coupled on p-(oxymethyl)phenylacetamidomethyl polystyrene.