bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Studies on Metal–Metal Interactions in Bismacrocyclic Ni(II) Complexes
Authors: Mochizuki Katsura 
Published: July 2006

Abstract
Studies on five Ni(II) complexes, i.e., 7,7′-polymethylenebis[2,12-dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),2,11,13,15-pentaene]dinickel(II) per-chlorates with polymethylene bridges of 2–6-C length, by cyclic voltammetry and differential pulse polarography, have revealed that the half-wave potentials of the [NiIINiII]/[NiIINiIII] and [NiIINiIII]/[NiIIINiIII] couples are not changed among the hexa- to tetramethylene derivatives but shifted toward the positive side in the following order: tetramethylene&lt;trimethylene&lt;ethylene derivative. These results are explainable in terms of the electrostatic repulsion due to these two metal ions.
The Cyclic Voltammetry of p-Tropoquinone Acetals
Authors: Mori Akira , Hirayama Shun-ichi , Goto Yasutomo , Takeshita Hitoshi 
Published: July 2006

Abstract
The cyclic voltammetry of p-tropoquinone mono- and bisacetals was analyzed. Monoacetals showed an irreversible redox couple and an oxidation wave around +0.16 to −0.1 V vs. Ag/AgCl, the latter of which was due to a dianion species.
The Selective Liquid-Phase Oxidation of 3,4,5-Trimethoxytoluene to 3,4,5-Trimethoxybenzaldehyde
Authors: Kitajima Nobumasa , Takemura Kazuya , Moro-oka Yoshihiko , Yoshikuni Tadatsugu , Akada Mitsuo , Tomotaki Yoshihisa , Taniguchi Masatoshi 
Published: July 2006

Abstract
The selective liquid-phase oxidation of 3,4,5-trimethoxytoluene to 3,4,5-trimethoxybenzaldehyde, an important chemical intermediate for medicine production, was developed; when 2.0 mmol of the reactant was heated at 110°C for 2 h in an autoclave under 3 atm O2 with 10 ml of acetic acid in the presence of 0.75 mmol of Co(OAc)2–Mn(OAc)2 (3:1 mole ratio), a 92% yield of the aldehyde was obtained.
Solution Structure and Preferred Orientation of 3,7-Dichloro-10H-phenothiazine Dissolved in Nematic Liquid Crystal
Authors: Fujiwara Hideaki , Watanabe Masayuki , Sasaki Yoshio 
Published: July 2006

Abstract
1H NMR spectrum of the title compound was measured in a nematic liquid crystal ZLI1167 and analyzed utilizing modified versions of the LAOCN program. Direct couplings obtained were interpreted on the basis of a folded structure of tricyclic framework. The results show that the dihedral angle between the two benzene rings is 153.1±2.0° and the angle of S···N–H is 170.9±6.7°. Hence a “H-intra” conformation is dominant in a mobile state dissolved in the nematic liquid crystal. The preferred orientation of this molecule in ZLI1167 is discussed by comparing the results with those of the dibromo analogue reported previously and by comparing the principal axes of the order tensor with those of the moment of inertia. The chlorine and bromine atoms are supposed to exert a special steric effect on the ordering of these molecules.
Effects of Supporting Electrolyte and pH on Charge Transport within Electropolymerized Poly(o-phenylenediamine) Films Deposited on Graphite Electrodes
Authors: Oyama Noboru , Ohsaka Takeo , Chiba Kazuyuki , Takahashi Katsuhiko 
Published: July 2006

Abstract
The homogeneous charge-transport process within electropolymerized electroactive poly(o-phenylenediamine) (PPD) films on graphite electrodes in various supporting electrolytic solutions (i.e., NaCl, NaClO4, Na2SO4, LiCl, CF3COONa, tetraethylammonium chloride (TEACl) and sodium p-toluenesulfonate (NaPTS)) at various pH’s was examined by potential-step chronoamperometry and chronocoulometry. The overall charge-transport process was found to obey Fick’s diffusion laws and thus the apparent diffusion coefficients (Dapp) for the diffusion-like charge-transport process were estimated. The Dapp values for the oxidation and reduction processes (i.e., Dappa and Dappc) were almost the same at pH 1.0 irrespective of the thickness of PPD films and were actually independent of the supporting electrolytes except for NaPTS. As pH was increased from 1 to 7, the Dappa values decreased slightly from ca. 5.6×10−8 to 1.6×10−8 cm2 s−1 and the Dappc values did more largely from ca. 5.6×10−8 to 2.2×10−9 cm2 s−1. This behavior was essentially common to all the supporting electrolytes examined. Such pH dependences of Dappa and Dappc are discussed on the basis of the fact that the charge-transport process within PPD films involves the intrinsic electron-transfer process between adjacent electroactive sites as well as the proton addition–elimination process, the charge-compensating counterion motion, the motion of solvent and the segmental motion of the polymeric chain. Especially, it is demonstrated that in this system the proton addition–elimination process must necessarily occur in order for the charge-transport process to proceed.
Equations-of-Motion Method for the Electronic Transitions to Compound (1p-1h)+(2p-2h) States
Authors: Shibuya Tai-ichi , Funada Tadashi , Gotoh Haruo 
Published: July 2006

Abstract
The equations-of-motion (EOM) method proposed by Shibuya and McKoy (Phys. Rev., A2, 2208 (1970); J. Chem. Phys. 58, 500 (1973)) has been extended to include (2p-2h)-state creation and annihilation operators in the excitation operator Oλ†.
Precise Measurement of Helium Isotopes in Terrestrial Gases
Authors: Sano Yuji , Wakita Hiroshi 
Published: July 2006

Abstract
Helium isotope ratios of terrestrial natural gas samples were measured using a high-precision mass spectrometer and an ultrahigh-vacuum purification line. The line is equipped with a charcoal trap held at 40 K using a helium expansion refrigerating machine. To avoid interference, Ne was completely separated from He by the trap before the gas was admitted to the mass spectrometer. Ion beams of 3He and 4He were measured at the same time by a double collector system. A resolving power of about 550 at the 5% level of the peak height was attained for the complete separation of 3He ions from those of HD and H3. Precision and reproducibility of the helium isotope ratio were less than 1%, examined by repeated measurements of an air standard. Accuracy of the ratio was checked by comparing observed data with reports in the literature.
Crystal and Molecular Structure of Cobalt(II)mercury(II) Thiocyanate Adducts Having a New Layer Structure
Authors: Kinoshita Hisashi , Ouchi Akira 
Published: July 2006

Abstract
N-Methyl-2-piperidone adduct and dimethyl sulfoxide adduct of cobalt(II)mercury(II) thiocyanate were synthesized and their crystal and molecular structures were determined by the single-crystal X-ray diffraction technique. The former adduct is triclinic with a space group P\bar1, a=8.488(3), b=17.206(7), c=8.466(3) Å, α=103.72(1)°, β=90.00(1)°, γ=100.85(1)°, Z=2, while the latter adduct is orthorhombic with a space group P212121, a=8.418(3), b=27.389(10), c=8.407(3) Å, Z=4, and the final R values obtained were 0.059 and 0.066, respectively. In these adducts each mercury atom is in the tetrahedral geometry, coordinated with four sulfur atoms of the thiocyanate (SCN) ions, and each cobalt atom is in the octahedral geometry, coordinated with four nitrogen atoms of SCN ions and two oxygen atoms of the Lewis-base molecules which occupy the trans-positions. Each pair of different kinds of metal atoms are bridged by an SCN ion forming a 16-membered ring of Co2Hg2(SCN)4; these are linked, forming a two-dimensional network. The Lewis-base ligands are extended perpendicular to the plane on both sides. The complex layers are piled up in parallel, and there are no chemical or hydrogen bondings between the layers. This is a new type of the structure for CoHg(SCN)4L2 (L=Lewis base) type adducts.
Rotational Isomerism in Fluorene Derivatives. X. The Conformational Equilibria of 9-Substituted 9-(2-Methylthiophenyl)- and 9-Substituted 9-(2-Methylsulfinylphenyl)fluorene Derivatives
Authors: Nishida Akiko , Takamuku Michinao , Fujisaki Shizuo , Kajigaeshi Shoji 
Published: July 2006

Abstract
Several 9-substituted 9-(2-methylthiophenyl)fluorene derivatives and their oxidation products, 9-substituted 9-(2-methylsulfinylphenyl)fluorene derivatives were prepared. Each equilibrium constant was investigated and the conformational equilibria ap\ightleftarrowssp of these compounds were discussed on the basis of nonbonding intramolecular interactions (attraction or repulsion) between 2-substituents in phenyl moieties (methylthio or methylsulfinyl) and fluorene ring or 9-substituents. It was found that the conformational equilibria were effected by the electronic properties of methylthio and methylsulfinyl groups. Kinetic data for internal rotation of a few compounds were shown.
Synthesis of Substituted 1,3-Dienes by the Reaction of Alkenesulfonyl Chlorides with Olefins Catalyzed by a Ruthenium(II) Complex
Authors: Kameyama Masayuki , Shimezawa Hiroshi , Satoh Takeshi , Kamigata Nobumasa 
Published: July 2006

Abstract
Alkenesulfonyl chlorides reacted with vinylarenes in the presence of a catalytic amount of dichlorotris(triphenylphosphine)ruthenium(II) to give substituted 1:1 adducts, which were dehydrochlorinated and desulfonylated successively to form substituted (E,E)-1,3-dienes in good yield.
Studies on Lignan Lactone Antitumor Agents. IV. Synthesis of Glycosidic Lignan Variants Related to α-Peltatin
Authors: Saito Hitoshi , Nishimura Yoshio , Kondo Shinichi , Takeuchi Tomio , Umezawa Hamao 
Published: July 2006

Abstract
Glycosidic variants of 1-β-hydroxy-α-peltatin and 1-β-hydroxy-8-O-methyl-α-peltatin were synthesized by glycosidation of 4′,8-di-O-benzyloxycarbonyl-1-β-hydroxy-α-peltatin or 4′-O-benzyloxycarbonyl-1-β-hydroxy-8-O-methyl-α-peltatin with the corresponding glucopyranose or 2-amino-2-deoxyglucopyranose derivatives. Among synthesized compounds, cyclic acetal of 1-O-β-(β-d-glucopyranosyl)-8-O-methyl-α-peltatin showed antitumor activity in mice with leukemia L-1210.
A General Method for the Synthesis of Both Enantiomers of Optically Pure β-Hydroxy Esters from (S)-(p-Chlorophenylsulfinyl)acetone Easily Obtainable by Kinetic Resolution with Bakers’ Yeast
Authors: Fujisawa Tamotsu , Fujimura Atsushi , Sato Toshio 
Published: July 2006

Abstract
Both enantiomers of various optically pure (R)- and (S)-β-hydroxy esters were generally synthesized from (S)-(p-chlorophenylsulfinyl)acetone obtained by kinetic resolution with bakers’ yeast, followed by γ-alkylation, diastereoselective reduction, subsequent introduction of ester group and reductive elimination of the sulfinyl group. The key step of the diastereoselective reduction of (S)-β-keto sulfoxides was performed with diisobutylaluminum hydride to give (R)c-(S)s-β-hydroxy sulfoxides or after complexation with zinc chloride followed by addition of diisobutylaluminum hydride to give (S)c-(S)s-β-hydroxy sulfoxides which were easily separated in an optically pure form by easy crystallization or separation by silica-gel chromatography due to the p-chlorophenyl moiety in the β-hydroxy sulfoxides. The utility of the present method could be successfully demonstrated in the synthesis of both (+)- and (−)-corynomycolic acids from optically pure methyl esters of (R)- and (S)-3-hydroxyoctadecanoic acid by alkylation with tetradecyl iodide at α-position and hydrolysis.
Electron Coupled Proton Transport Mediated by [Fe4S4(SC6H4-p-n-C8H17)4]2− in Liquid Membrane
Authors: Tanaka Koji , Masanaga Mari , Tanaka Toshio 
Published: July 2006

Abstract
Electrochemical reduction of [Fe4S4(SC6H4-p-n-C8H17)4]2− ([4-Fe]2−) dissolved in a CH2Cl2 phase of the CH2Cl2/H2O two phase system is followed by protonation to give [4-Fe]3−–H+ when the pH of the H2O phase is lower than 7.0, and protonated and deprotonated [4-Fe]3− exist as an equilibrium mixture in the CH2Cl2 phase. On the other hand, no protonation takes place upon the reduction of [4-Fe]2− in the CH2Cl2 phase contacting with the H2O phase with the pH higher than 7.0. The electron transport conducted in a liquid membrane composed of the H2O (W1), CH2Cl2, and H2O (W2) phases containing sodium dithionite as an electron donor, (n-Bu4N)2[4-Fe] as a mediator, and disodium anthraquinone-1,5-disulfonate (Na2AQS) as an electron acceptor, respectively, revealed that protonated [4-Fe]3−–H+ mediates electron coupled proton transport in the liquid membrane, while the deprotonated cluster has no ability of electron transport in the same system.
Enhancement of Sulfation of CaO by Fe2O3 in the Oxidative-Sorption Process for SO2 Removal Using Fe2O3/CaO Binary Sorbents
Authors: Dairaku Yukinori , Sato Satoshi , Sodesawa Toshiaki , Nozaki Fumio 
Published: July 2006

Abstract
For the oxidative sorption of SO2 using Fe2O3/CaO binary sorbents prepared by the usual impregnation method, reactivities and capacities for SO2 removal have been investigated with TG measurements at temperatures near 500 °C in a stream of air containing SO2 in concentration from 2 to 11%. Both the reactivities and the capacities of the sorbents were exceedingly enhanced by addition of Fe2O3 into CaO such small amounts as 0.1–0.8wt%, and further Fe2O3-loading over 1.0wt% resulted in a lowering in promoting effects. The changes in surface area and pore-size distribution with a variation of Fe2O3 content were also measured in order to discuss the correlation between chemical reactivity for SO2 removal and physical property of the Fe2O3/CaO sorbents. In addition, Fe2O3–CaO mechanically mixed sorbents and the other binary sorbents such as Fe2O3/MgO or V2O5/CaO were tested to compare with the Fe2O3/CaO sorbents.
The Oxidative Polymerization of 2-Methyl-6-(3,7-dimethyl-2,6-octadienyl)phenol
Authors: Hyun Sang-Heon , Nishide Hiroyuki , Tsuchida Eishun , Yamada Shigetoshi 
Published: July 2006

Abstract
2-Methyl-6-(3,7-dimethyl-2,6-octadienyl)phenol (MGP) was prepared by the reaction of o-cresol and 1-chloro-3,7-dimethyl-2,6-octadiene in the presence of sodium. This MGP was then oxidatively polymerized with a copper-pyridine catalyst to yield poly[oxy[3-methyl-5-(3,7-dimethyl-2,6-octadienyl)-1,4-phenylene]]. The MGP and 2,6-dimethylphenol (DMP) copolymerized with a similar reactivity to form copolymer. The properties of the polymers were also studied.
Gamma-Irradiation Effect on the Catalytic Behavior of Binary Oxide Catalysts
Authors: Hassan E A , Abd El-Salaam K M , Said A A 
Published: July 2006

Abstract
Decomposition of hydrogen peroxide in aqueous solution was used for testing the effect of gamma radiation on the catalytic activity of CoxFe3−xO4, with O≤x≤3.0. The activity variation was interpreted in terms of the catalysts electronic structure. The presence of Co2+ on octahedral sites is superior to Fe2+ in the catalytic process. However, γ-irradiation can produce a considerable effect on the catalytic activity due to its influence on the active site concentration and cation distribution.
Charge-Transfer Complexes of Nitrones. VI. Molecular Complexes of Nitrones with Iodine
Authors: El-Din Ahmed M Nour , Tawfik Abdel-Razak 
Published: July 2006

Abstract
Charge-transfer (CT) complexes between some α-aryl and α-(heterocyclic substituted)nitrones and iodine as σ-acceptor in dichloromethane have been investigated spectrophotometrically. From the energies of the charge-transfer transitions, the ionization potentials of the nitrones have been obtained. The stoichiometry of the complexes has been determined. All the results are in agreement with the n–σ* nature of these complexes with some involvement of the π-orbital of the donor.
Peroxy Acid Oxidations. II. A Kinetic and Mechanistic Study of Oxidation of α-Diketones
Authors: Panda Radhasyam , Panigrahi Akhil Krishna , Patnaik Chakrapani , Sahu Sabita Kumari , Mahapatra Sabita Kumari 
Published: July 2006

Abstract
The kinetics of Baeyer-Villiger oxidation of biacetyl and benzil by peroxomonophosphoric acid and peroxomonosulfuric acid have been studied in different pH ranges at 308 K. The reactions are second order; first order each in peroxy acid and in diketone concentrations at constant pH. The oxidation rate is strongly pH-dependent; the rate increases with increase in pH. From the pH-rate data the reactivity of different peroxo species, in the oxidation, has been determined. A mechanism consistent with rate-determining nucleophilic attack of peroxo species on carbonyl carbon of the diketone molecule has been proposed. Acetic acid and benzoic acid are respectively found to be the products of oxidation of biacetyl and benzil.
Nitriles in Organic Synthesis. The Chemical Behavior of [1-(2-Furyl)-ethylidene]- and [1-(2-Thienyl)ethylidene]malononitriles
Authors: El-Maghraby Mohamed Abdallah , Sadek Kamal Usef , Selim Maghraby Ali , Elnagdi Mohamed Hilmy 
Published: July 2006

Abstract
The chemical behavior of [1-(2-furyl)ethylidene]- and [1-(2-thienyl)ethylidene]malononitriles 1a and b toward electrophilic reagents, active methylene reagents and (arylmethylene)malononitriles is described.
Reaction Network for Selective Oxidation of Propene on a (Mo–Pr–Bi)O/SiO2 Catalyst
Authors: López Nieto J M , Tascón J M D , Kremenic G 
Published: July 2006

Abstract
Oxidation of propene on a Mo4Pr0.5Bi0.5Ox/SiO2 catalyst was studied in order to establish the reaction network. In the temperature range 598–653 K the primary reaction products were propenal (main product), acetone, acetaldehyde, and carbon dioxide. Other products (mainly aldehydes and acids) could be classified as secondary reaction products. From studies of oxidation of the primary unstable products and the kinetics of formation of minor primary products it is concluded that both, acetaldehyde and carbon dioxide, are formed through parallel and consecutive reactions. Acetone formation is strongly influenced by reaction temperature, probably due to changes in the active centers of the catalyst.
35Cl NQR Study and Addition Reactions to Cyclohexene of Cyclic N-Chloro Amides (Imides)
Authors: Nagao Yoshitaka , Katagiri Shigeyoshi 
Published: July 2006

Abstract
35Cl NQR frequencies were measured for N-chloro-2-pyrrolidinone, N-chloro-4,4-dimethyl-2-oxazolidinone, N-chloro-2-oxazolidinone, N-chloroglutarimide, and N-chlorosuccinimide. The ionicities of the N–Cl bonds were estimated on the basis of those measurements. These ionicities were related to the total yields of the 1,2-addition in the photochemical reaction with cyclohexene. When the value of the ionicity neared zero, the total yield increased.
Optical Resolution of α-Ethylbenzylamine and Its Application as a Resolving Agent
Authors: Nohira Hiroyuki , Nohira Misako , Yoshida Shin-ichi , Osada Ayako , Terunuma Daiyo 
Published: July 2006

Abstract
(±)-α-Ethylbenzylamine ((±)-1) was efficiently resolved into a pair of enantiomers by fractional crystallization as its cis-2-benzamidocyclohexanecarboxylic acid (2) salt. Moreover, it was found that each of both enantiomers was obtained by mutual resolution between (±)-1 and (±)-2. The optically active amine (1) was substantially capable of resolving a variety of chiral carboxylic acids.
Polarographic and Cyclic Voltammetric Reduction of p-Chlorobenzaldehyde Isonicotinoylhydrazone
Authors: Reddy Papammagari Raveendra , Rao Sukuru Brahmaji 
Published: July 2006

Abstract
p-Chlorobenzaldehyde isonicotinoylhydrazone (p-Cl-BAINH) exibits a single wave in acid buffered solutions (pH 2–6) and two waves in alkaline buffered solutions (pH 7–9). However, the compound exhibits three cathodic peaks in acid solution and two cathodic peaks in alkaline solutions. The electrode reactions are attributed to the reductive cleavage of =N–N– linkage and the reduction of the amide formed in the cleavage.
Temperaturabhängigkeit der Fluoreszenz von Gd3+ in Wässriger Lösung
Authors: Baumann Markus 
Published: July 2006

Abstract
The effects of pressure and temperature on the fluorescence of aqueous Gd3+ solution have been studied, the following results being obtained: (a) The pressure up to 100 MPa gives no influence on emission, (b) The fluorescence diminishes with temperature rise, nearly disappearing at 200 °C.
Ring Size Effect on [2+2] Photochemical Cycloaddition of Enones with Cyclic Olefins
Authors: Tada Masahiro , Nieda Yuuki 
Published: July 2006

Abstract
Photochemical reaction of 3-substituted 2-cyclohexen-1-ones with methyl 1-cyclohexene-1-carboxylate gave only head-to-tail, cis-transoid-cis photoadduct. The photoadducts of 3-methyl-2-cyclohexen-1-one with methyl 1-cyclopentene-1-carboxylate and with methyl 1-cyclobutene-1-carboxylate had head-to-head, cis-transoid-cis ring systems.
The Structure of Galantinamic Acid, a New Amino Acid in a Peptide Antibiotic Galantin I
Authors: Wakamiya Tateaki , Terashima Shin-ichi , Kawata Mitsuyasu , Teshima Tadashi , Shiba Tetsuo 
Published: July 2006

Abstract
A new amino acid named galantinamic acid was found as one of the constituent amino acids in a peptide antibiotic galantin I. The primary structure of galantinamic acid was determined chemically and spectrometrically to be 6,10-diamino-2,3,5-trihydroxydecanoic acid.
Asymmetric Catalytic Hydrogenations of Oximes and Benzylimino Derivatives of Chiral Pyruvamides
Authors: Munegumi Toratane , Harada Kaoru 
Published: July 2006

Abstract
Oximes and benzylimino derivatives of chiral pyruvamides were hydrogenated over palladium hydroxide on charcoal in several solvents. Oximes of pyruvamides containing (R)-α-ethylbenzylamine as a chiral source gave (S)-alanine in excess (up to 70% e.e.) through the hydrolyses of the hydrogenated products.
The Photocyclization of N,N-Dialkyl β-Oxo Amides on Silica Gel
Authors: Hasegawa Tadashi , Moribe Jun-ichi , Yoshioka Michikazu 
Published: July 2006

Abstract
β-Oxo amides 1 adsorbed on silica gel underwent photocyclization via δ-hydrogen abstraction to give the five-membered lactams 2. No severe restrictions on the molecular motion could be observed in the photoreaction on the silica-gel surface. However, the relative photoreactivity of N,N-dibenzyl-2-benzoylacetamide (1a) to N,N-dibenzyl-2-benzoylpropionamide (1b) increased greatly on the silica-gel surface compared to that in solution, probably because of the greater keto content on the surface.
NQR of 35Cl, 127I, and 121Sb in I3Cl2SbCl6 and ICl2SbCl6
Authors: Mishima Mitsuo , Okuda Tsutomu 
Published: July 2006

Abstract
NQR spectra due to 35Cl, 127I, and 121Sb in I3Cl2SbCl6 and ICl2SbCl6 have been observed in the temperature range 77 K to melting point. The Zeeman effect on the single crystals of these complexes has been examined. In I3Cl2SbCl6 the η-values for the I atoms contributing to the higher and the lower NQR frequencies are 0.73 to 0.09, respectively, whereas in ICl2SbCl6 the η-value for the I atom is 0.15. In these complexes the 35Cl NQR lines which yield large η-values (0.42 to 0.56) are assigned to the bridging Cl atoms. The η-values for the other Cl atoms, except the Cl atoms in the ICl2+ ion which have η-values of 0.13 to 0.15, are negligibly small. The Sb atoms in both complexes have considerably large η-values (0.39). The orbital populations have been calculated from the NQR parameters. The bonding in the cations is explained on the basis of an approximation using only p orbitals of the I atom.
Hydrodynamic Characterization of Amylose–SDS Complex by Viscosity Measurement
Authors: Yamamoto Masako , Harada Shoji , Nakatsuka Thoru , Sano Takayuki 
Published: July 2006

Abstract
The hydrodynamic behavior of amylose with and without sodium dodecyl sulfate (SDS) has been examined by viscosity measurements. Two distinct viscosity phenomena have been observed by complexation; one is the increase at the first stage of binding of SDS, which disappears by an addition of salt, and the other is the subsequent decrease in the region of further binding of SDS. These results are interpreted by an idea that the expansion of the complex occurs by an electrostatic repulsion of the bound SDS molecules and the contraction of the complex by a hydrophobic interaction of cooperatively bound SDS molecules. This idea was confirmed further by experiments using amyloses of different length and homologous surfactants of SDS.