bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the Aqueous Solutions of Guanidinium Salts. IX. Activity Coefficients of Biguanide Hydrochloride and Sucrose in Aqueous Ternary Solutions at 25 °C
Authors: Miyajima Koichiro , Nakanishi Shigeo , Nakagaki Masayuki
Published: July 2006

Activity coefficients for the ternary system biguanide·HCl–sucrose–water were determined by the isopiestic vapor pressure method at 25 °C. Biguanide hydrochloride (Bg·HCl) and sucrose each decreased the activity coefficient of the other solute, showing a mutual salting-in effect. The excess free energy of mixing was negative and its magnitude was about twice as large as that of the system urea–sucrose–water. The pair interaction parameter {Bg·HCl–sucrose}g was calculated to be −89.2 (cal mol−2 kg). Thermodynamic properties of this system were found to be similar to those of the system urea–sucrose–water, indicating that Bg·HCl exerted a structure breaking effect on the aqueous solutions of sucrose as urea did.
Energy Levels and g Values of Some Rare Earth Crystals with f2 Configuration
Authors: Kato Yoshifumi , Takada Hirokazu
Published: July 2006

The energy levels of the rare earth ions in praseodymium ethyl sulfate, magnesium praseodymium nitrate, and thulium ethyl sulfate crystals are calculated by using an extended Hamiltonian for 4f2 configuration. The Hamiltonian includes two-body electrostatic interactions, spin-other-orbit interactions and two-body pseudomagnetic interactions as configuration-mixing parameters in addition to the Slater, spin-orbit coupling and crystal-field parameters. The standard deviations for praseodymium ethyl sulfate, magnesium praseodymium nitrate and thulium ethyl sulfate are respectively 10.1 cm−1 for 25 observed levels by using 13 parameters, 3.8 cm−1 for 12 observed levels by using 11 parameters, and 8.9 cm−1 for 32 observed levels by using 13 parameters. These results are consistent with similar studies of rare earth ions doped in the LaCl3 and LaF3 crystals. Most of the calculated Zeeman splitting factors (g value) parallel to the principal axis of the crystals also are in fairly good agreement with the experimental values. Some discussion is given as to the effect of configuration interactions, the accuracy of wave functions obtained and the discrepancy between some of the calculated g values and the observed ones.
Magnetic Circular Dichroism of Praseodymium Ethyl Sulfate and Praseodymium–Magnesium Double Nitrate
Authors: Kato Yoshifumi , Asano Motoshi
Published: July 2006

The magnetic circular dichroism of praseodymium ethyl sulfate and praseodymium–magnesium double nitrate was measured in the visible wave number region at low temperatures down to 17 K. Analysis was carried out for six absorption bands of praseodymium ethyl sulfate and three bands of praseodymium–magnesium double nitrate. With available information on energy levels., the g values of the crystal-field levels relevant to absorptions were derived from the MCD parameters obtained. These values are in good agreement with those from other methods.
Layered Compounds. LXI. Carbon-13 NMR Study of [n]-, [n.n]-, and Multilayered [2.2]Paracyclophanes
Authors: Kaneda Takahiro , Otsubo Tetsuo , Horita Hisanori , Misumi Soichi
Published: July 2006

The carbon resonances of several [n]paracyclophanes (n=8–12) were assigned with the aid of partially deuterated derivatives. The 13C NMR spectra of the title paracyclophanes were examined from viewpoints of the steric compression effect and the ring-current effect. Although the compression effect is a dominant factor for carbon resonances of closely stacked paracyclophanes, the ring-current effect was evidently observed in the spectra of [10]paracyclophane–[10](9,10)anthracenophanepair, [3.3]paracyclophane, and multilayered [2.2]paracyclophanes.
Thione S-Imides. The Reaction with Carbon-Hetero Atom Double Bond
Authors: Saito Takao , Oikawa Isao , Motoki Shinichi
Published: July 2006

9-Fluorenethione S-p-toluenesulfonimide reacted as a 1,3-dipole with imines, oximes, and thiones to form (3+2)cycloadducts, while with symmetrical azines and aldehydes, unsymmetrical azines, N-(p-tolylsulfonyl) imines and fluorenone were obtained as a result of the decomposition of the cycloadducts.
Substituent Effects in Heterogeneous Catalysis. VI. Competitive Hydrogenation of Methylenecyclohexane and 2-Methyl-methylenecyclohexane over Platinum Group Metals
Authors: Taya Kazuo , Morimoto Shinya , Abe Chieko , Nomura Kazumi , Nomura Okio , Tanaka Kazunori
Published: July 2006

Methylenecyclohexane and its 2-methyl derivative were hydrogenated competitively in cyclohexane at 30 °C over platinum group metals. The methyl derivative was less reactive than the unsubstituted olefin on all the metal catalysts used. The reactivity of the methyl derivative relative to the unsubstituted olefin was not much different in going from one catalyst to another. However, Pd was unique in its very high activity for double bond migration. MINDO/2 calculations have revealed that the olefinic double bonds of the substituted and unsubstituted olefins are essentially identical in bond order but somewhat different in charge density. The observed methyl substituent effect is compared with that observed previously in hydrogenation of cyclohexanone and its 2-methyl derivative.
The Reaction of 2-(Trialkylsiloxy)furans with Lead(IV) Acetate. The Synthesis of dl-Pyrenophorin
Authors: Asaoka Morio , Yanagida Noboru , Sugimura Naoyuki , Takei Hisashi
Published: July 2006

The reaction of 2-(trimethylsiloxy)furans with lead(IV) acetate afforded the corresponding α,β-unsaturated γ-acetoxy-γ-lactones in good yields. The lactones were easily converted into the corresponding 3-acylacrylic acids. Utilizing this reaction, dl-pyrenophorin was synthesized.
Synthesis of Linear Pyranocoumarins: Xanthoxyletin, 4-Methyl-xanthyletin, and 4-Phenylxanthyletin
Authors: Ahluwalia Vindo Kumar , Bhat Krishna , Prakash Chandra , Bala Shashi
Published: July 2006

A convenient synthesis of linear pyranocoumarins (2H,8H-benzo[1,2-b: 5,4-b′]dipyran-2-ones), viz., xanthoxyletin, 4-methylxanthyletin and 4-phenylxanthyletin is described which uses blocking the 8-position of appropriate 7-hydroxycoumarin derivatives with iodine and 1,1-dimethyl-2-propynylation followed by cyclisation.
Fluorination with Xenon Difluoride. XXII. The Role of Catalyst and Temperature on the Fluorination of Norbornene and Norbornadiene
Authors: Gregorcic Ana , Zupan Marko
Published: July 2006

The reaction of norbornene was used as a mechanistic probe to elucidate the effect of catalyst (HF, HF–pyridine, BF3, BF3–etherate, and pentafluorothiophenol) and temperature (from −61 °C to 25 °C) on liquid phase fluorinatioh with xenon difluoride, resulting in the formation of seven products, depending on the reaction conditions : fluoronortricyclane, 2-endo-5-exo-difluoronorbornane, 2-exo-7-anti-difluoronorbornane, 2-endo-5-exo-difluoronorbornane, 2-exo-5-exo-difluoronorbornane, 2-exo-3-exo-difluoronorbornane, and 2-exo-7-syn-difluoronorbornane. The catalyst has a significant effect on the reaction pathways, boron trifluoride etherate favouring the formation of 2-endo-5-exo- and 2-exo-5-exo-difluoronorbornane, while pentafluorothiophenol favoured the formation of fluoronortricyclane. The catalyst and temperature has much less effect on the reaction pathways in the case of norbornadiene, four products being formed: fluoronortricyclane, 3-endo-5-exo-difluoronortricyclane, 3-exo-5-exo-difluoronortricyclane, and 2-exo-7-syn-difluoro-5-norhornene. Pentafluorothiophenol as a catalyst, when used in a greater amount, favours the formation of fluoronortricyclane.
The Benzannelated Annulenes. Dibenzo[d,j]-6,8-bisdehydrothia[13]-, [15]-, and Dibenzo[f,l]-8,10-bisdehydrothia[17]annulene
Authors: Ojima J\={u}ro , Kusaki Kiyomi , Wada Kazuyo , Nakagawa Yukiko
Published: July 2006

The title compounds have been synthesized by the double Wittig reaction of bis[(triphenylphosphonio)methyl] sulfide dibromide with o-ethynylbenzaldehyde and/or o-ethynylcinnamaldehyde, followed by the oxidative coupling. The 1H-NMR spectra of these compounds gave no evidence for a ring current.
Asymmetric Synthesis Catalyzed by Chiral Ferrocenylphosphine–Transition Metal Complexes. I. Preparation of Chiral Ferrocenylphosphines
Authors: Hayashi Tamio , Mise Takaya , Fukushima Motoo , Kagotani Masahiro , Nagashima Nobuo , Hamada Yuji , Matsumoto Akira , Kawakami Sota , Konishi Mitsuo , Yamamoto Keiji , Kumada Makoto
Published: July 2006

As chiral ligands for transition metal complex catalyzed asymmetric reactions, various kinds of chiral ferrocenylphosphines, which have planar chirality due to 1,2-unsymmetrically substituted ferrocene structure and also have a functional group on the side chain of the ferrocene nucleus, were prepared. (S)-N,N-dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine [(S)-(R)-PPFA], (S)-N,N-dimethyl-1-[(R)-1′,2-bis(diphenylphosphino)ferrocenyl]ethylamine [(S)-(R)-BPPFA], and their dimethylphosphino derivatives were prepared by way of lithiation of optically resolved N,N-dimethyl-1-ferrocenylethylamine. The 1-(dimethylamino)ethyl group on the ferrocenylphosphines was converted stereospecifically by nucleophilic substitution reactions into 1-methoxy-, 1-hydroxy-, 1-diphenylphosphino-, and several 1-(dialkylamino)ethyl groups. 1-Diphenylphosphino-2-(dimethylaminomethyl)ferrocene (FcPN) was optically resolved via its phosphine sulfide dibenzoyltartaric acid salt. The relationship between CD spectra of the chrial ferrocenylphosphines and the configuration of their planar chirality is discussed.
Spin-trapping Reactions in γ-Irradiated Benzene Solutions. Generation of Authentic Spin-adduct Radicals
Authors: Ichikawa Tsuneki , Yoshida Hiroshi
Published: July 2006

Spin-trapping in γ-irradiated solutions of chlorinated hydrocarbons in benzene by using 2,4,6-tri-t-butylnitrosobenzene revealed that transient free radicals are generated almost exclusively by the dissociative electron attachment to the solutes. This provides a simple, useful method for preparing the authentic spin-adducts of hydrocarbon radicals.
Photoelectron Angular Distribution Measurements for Some Aliphatic Alcohols, Amines, and Halides
Authors: Utsunomiya Chikatoshi , Kobayashi Tsunetoshi , Nagakura Saburo
Published: July 2006

The angular distributions for the He I photoelectron spectra of some aliphatic alcohols, amines, and halides were measured in order to reexamine the assignments of the so-called p-type photoelectron spectral bands in the He I region of these molecules. The second band of methanol and the third band of ethanol were assigned to the in-plane n orbitals localized mainly on the oxygen atom. Furthermore, it was found that the angular distributions of photoelectrons were useful for the conformational analysis of molecules and that the sum of β values was conserved for these compounds.
Kinetic Studies of the Electron Transfer Reactions in Iron(II) and Iron(III) Systems. IX. Electron Transfer Reactions between Iron(II) and Iron(III) in Water Mixed with Ethanol, 1-Propanol, Ethylene Glycol, Glycerol, and Pentaerythritol
Authors: Wada Goro , Ohta Youko , Hayashida Sachiko , Sugino Harumi , Mizui Toyomi , Aihara Yumiko
Published: July 2006

The rate constants of the electron transfer reactions between Fe(II) and Fe(III) were determined in mixed solvents of water and alcohols, such as ethanol, 1-propanol, ethylene glycol, glycerol, and pentaerythritol. From the acid concentration dependence of the rate, the predominant path of the reaction was estimated to be Fe2+-Fe(OH)2+ path with a rate constant kH. The rate constant kH increases with increase in the mole fraction x of ethanol and 1-propanol, and decreases with increase in x of methanol, ethylene glycol, glycerol, and pentaerythritol. A straight line is obtained when In kH is plotted against the reciprocal dielectric constant D−1 of the mixed solvents for the latter group of alcohols. From the slope of the straight line the distance between Fe2+ and Fe(OH)2+ is estimated to be 7.8 Å at the intermediate stage of the reaction. Therefore, the reaction is mostly controlled by the electrostatic repulsive force, being influenced by D of the mixed solvents.
Crystal and Molecular Structure of (Ethyl methacrylate)bis(triphenylphosphine)nickel(0)
Authors: Komiya Sanshiro , Ishizu Junichi , Yamamoto Akio , Yamamoto Takakazu , Takenaka Akio , Sasada Yoshio
Published: July 2006

The crystal and molecular structure of (ethyl methacrylate)bis(triphenylphosphine)nickel, (CH2=C(CH3)–COOC2H5) (PPh3)2Ni, has been determined by single-crystal X-ray analysis. The crystals are monoclinic, space group P21/c, with unit-cell dimensions a=13.690(2), b=16.855(2), c=15.699(1)Å, β=105.09(1)°, and Z=4. The structure was solved by the heavy-atom method and refined by block-diagonal least-squares technique, using 4701 independent reflections, the final R value being 0.084 for |Fo|≥3σ(F). The two phosphine ligands and the two olefinic carbon atoms comprise a distorted square-planar configuration about the Ni atom. The Ni–β-CH2 bond (1.976(8)Å) is significantly shorter than the Ni–α-C bond (2.029(7)Å). The difference is explained by the contribution of polarized resonance structure in metal-olefin bonding.
Electron Transfer Reaction between Δ2,2′-Bi-1,3-dithiole (TTF) and 7,7,8,8-Tetracyanoquinodimethane (TCNQ). Electron Donating Property of TTF
Authors: Yamagishi Akihiko , Iida Yôichi
Published: July 2006

The reaction between Δ2,2′-bi-1,3-dithiole (TTF) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) in ace-tonitrile solution, TTF+TCNQ\ightleftharpoonsTTF+·+TCNQ\ewdot, was analyzed spectrophotometrically. The thermodynamical data of chemical equilibrium were determined to be K=(2.8±0.1)×10−3 at 11 °C, ΔH=−6.7±1.3 kJ mol−1 and ΔS=−72.8±17 J K−1 mol−1. The reaction-rate study of the equilibrium in several solvents was also made by temperature-jump technique. The difference in the electron-donating properties between TTF and N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD) is discussed by comparing the results with those of the reaction between TMPD and TCNQ.
The Enantioface-differentiating Hydrogenation of the C=O Double Bond with Asymmetrically Modified Raney Nickel. XXXIII. The Preparation of (R)- and (S)-1,3-Butanediol from 4-Hydroxy-2-butanone
Authors: Murakami Shigeki , Harada Tadao , Tai Akira
Published: July 2006

The enantioface-differentiating hydrogenation of 4-hydroxy-2-butanone (I) to 1,3-butanediol(II) was conducted with asymmetrically modified metal catalysts. Among the modified catalysts examined, Raney nickel modified with a solution containing tartaric acid and NaBr (TA–NaBr–MRNi) gave the best results with respect to the optical and chemical yields. (R)-II, an optical purity of 69% was obtained in a quantitative chemical yield by the use of (R,R)-TA–NaBr–MRNi. (S)-II was also obtained by the use of (S,S)-TA–NaBr–MRNi. A simple method for the preparation of optically pure (S)-and (R)-II from the hydrogenation product was also developed.
The Reaction of Olefins with Chloroalkoxyalkanes and Formic Acid in Ether
Authors: Nishiura Kazuo , Tagano Tsutomu , Wada Yasuo , Tanimoto Shigeo , Okano Masaya
Published: July 2006

The reaction of olefins with chloromethoxymethane (CMM) and excess formic acid in ether, in the presence of ZnCl2 or HgCl2, afforded mainly four products, 1-chloro- and 1-formyloxy-2-(formyloxymethyl)alkanes, and 3,5-dialkyl-4-chloro- and 3,5-dialkyl-4-(formyloxy)tetrahydropyrans, in various yields. In the case of styrene, the chief products were limited to the former two. Similar products were obtained from 1-chloro-1-ethoxyethane (CEE), but their yields were quite low.
The Chloroiodination of Deactivated Olefins with Antimony(V) Chloride–Iodine and Iodine Monochloride
Authors: Uemura Sakae , Fukuzawa Shin-ichi , Okano Masaya , Sawada Seiji
Published: July 2006

By the reactions of olefins with an equimolar mixture of SbCl5 and I2 in carbon tetrachloride, various chloroiodoalkanes are obtained in fair to good yields. This method is applicable to various deactivated olefins, the reactions of which do not proceed by the reported method using a mixture of CuCl2 and I2. Iodine monochloride can aslo be used for this reaction, but in this case both the yield and the regiospecificity of the products are sometimes inferior.
Studies on Heterocyclic Analogs of Azulene. VI. Cycloadditions of Styryl-substituted Aza Analogs of Azulene with Dimethyl Acetylenedicarboxylate
Authors: Abe Noritaka , Nishiwaki Tarozaemon
Published: July 2006

8-[(E)-Styryl]-1-azaazulenes stereospecifically react with dimethyl acetylenedicarboxylate to form trans-7H-6a-azacyclobuta[j]cyclopent[cd]azulene (3), which undergoes thermal rearrangement into 3-[(E)-styryl]3H-2a-azacyclopent[cd]azulene and 3a,4-dihydro-3H-2a-azadicyclopent[cd, ij]azulene (7), or isomerization into 3H-2a-azacyclopenta[ef]heptalene by silica gel. Compound 7 is oxidized during the course of reaction to yield 11-oxo-2aH-7,10b-methano-2a-azacyclopenta[ab]cycloundecene, compound 3 forming 5a,6-dihydro-3H-2a-azadicyclopenta[ef, kl]heptalene upon reaction with acetylene. The formation of 3 could be accounted for in terms of a symmetry-allowed thermal [π2s+π2a+π6a] cycloaddition.
Efficient Regioselective Aldol Condensation of Methyl Ketones Promoted by Organoaluminium Compounds, and Its Application to Muscone Synthesis
Authors: Tsuji Jiro , Yamada Toshiro , Kaito Mitsumasa , Mandai Tadakatsu
Published: July 2006

Dialkylaluminium aryloxide in combination with a tertiary amine was found to be a good reagent for regioselective aldol condensation of methyl ketones at the methyl side. Regioselective aldol condensation of 2-octanone was carried out using diisobutylaluminium phenoxide–pyridine. The intramolecular aldol condensation of 2,15-hexadecanedione promoted by the same reagent gave a mixture of dehydromuscones in 65% yield. Its hydrogenation produced muscone.
The Total Syntheses of Chamaecynone, Isochamaecynone, and Dihydroisochamaecynone
Authors: Ando Masayoshi , Asao Toyonobu , Hiratsuka Norio , Takase Kahei , Nozoe Tetsuo
Published: July 2006

A novel acetylenic nor-sesquiterpene, chamaecynone, and its related natural products, isochamaecynone and dihydroisochamaecynone, have been synthesized starting from α-santonin. In the base-induced equilibration of three pairs of compounds, chamaecynone and isochamaecynone, 4βH,5β-13-noreudesm-11-yn-3-one and 4αH,5β-13-noreudesm-11-yn-3-one, and 4βH,5β-13-noreudesm-11-en-3-one and 4αH,5β-13-noreudesm-11-en-3-one, the ΔH values were determined to be +1.47 kcal/mol, +0.77 kcal/mol, and −2.28 kcal/mol respectively.
Correlation between Electron Capture Detector Response and Chemical Structure for 1,2,3,4,5,6-Hexachlorocyclohexane
Authors: Hattori Yukikazu , Kuge Yoshio , Asada Shingo
Published: July 2006

The relative sensitivities of an electron capture detector for four 1,2,3,4,5,6-hexachlorocyclohexane isomers were measured at different detector temperatures. The temperature dependence of the electron capture coefficients (K) for these compounds was determined. The K values of these compounds increased with a decrease in the detector temperature. These results show that the electron capture reactions of these compounds proceed non-dissociatively.
A Measurement of the Thermal Decomposition of CS2 behind Reflected Shock Waves
Authors: Saito Ko , Toriyama Yoko , Yokubo Teiji , Higashihara Tetsuo , Murakami Ichiro
Published: July 2006

The thermal decomposition of CS2 in Ar was investigated in the temperature range of 2000–2900 K by monitoring both the UV absorption and the visible emission of CS2. A typical induction zone was observed during the decomposition. It was found that the rate constant of the initiation reaction obtained from the induction zone was smaller than that reported by previous workers.
Reflectivity of Two-dimensional Cluster Compound, Nb3I8
Authors: Kawamura Haruki , Shirotani Ichimin , Tanaka Masashi , Tachikawa Kyoji , Tanaka Jiro
Published: July 2006

The reflectivity spectrum of two-dimensional cluster compounds, Nb3I8, is measured from 5×103 to 35×103 cm−1 and compared to that of Ag2F. The spectrum has four peaks, at 7.5, 11.8, 20.0, and 28.6×103 cm−1.
Mechanical Strength and Thermal Expansion of Sintered Rare Earth Orthophosphate(RPO)4
Authors: Hikichi Yasuo , Hukuo Ken-iti , Shiokawa Jiro
Published: July 2006

RPO4 powders, obtained by heating a hexagonal form RPO4·0.5H2O (R=La, Ce, Pr, Nd, or Sm) or a monoclinic form RPO4·2H2O (R=Y, Er, or Yb) at 800 °C for 3 h, were pressed into plates or spheres at 500 kgf/cm2 (1 kgf/cm2=98.0665 kPa) and sintered at 1500 °C for 60 min in the air, the sintered bulk density being above 90% of the theoretical. The mechanical strength and thermal expansion of the sintered RPO4 are : compressive strength 2300–3000 kgf/cm2, bending strength 320–500 kgf/cm2, and linear thermal expansion coefficients (30–900 °C) (5.75–10)×10−6.
Two-phase Darzens Condensation Reaction with Octopus Compounds as a Catalyst
Authors: Akabori Sadatoshi , Ohtomi Michiko , Yatabe Seiichi
Published: July 2006

The octopus compound, readily derived from hexakis(mercaptomethyl)benzene and 1-chloro-3,6,9-trioxadecane, was effectively employed as a catalyst in the two-phase Darzens condensation of carbonyl compounds with chloroacetonitrile to afford the corresponding oxiranes in good yields.
Comparison of Lewis Acids as Catalyst for the Alkylation of Benzene with s-Butyl Chloride
Authors: Segi Masahito , Nakajima Tadashi , Suga Sohei
Published: July 2006

The Friedel-Crafts alkylation of benzene with s-butyl chloride has been carried out in the presence of various Lewis acid catalysts. The relative order of catalyst activity is: AlBr3, AlCl3, MoCl5, SbCl5>TaCl5>NbCl5>FeCl3>ZrCl4>TiCl4>>WCl6. The effect of addition of nitromethane on alkylation has been investigated.
Preparation and Properties of N-(Pentafluoropropionyl)amino Acid
Authors: Kawa Hajimu , Ishikawa Nobuo
Published: July 2006

N-(Pentafluoropropionyl)amino acids, which were prepared by treating amino acids with hexafluoro-1,2-epoxypropane in diglyme, were found to be a versatile derivative of amino acids in gas chromatographic analysis.
Catalytic Geometrical Isomerization of cis-Chrysanthemaldehyde and Related Ketones
Authors: Sasaki Tadashi , Eguchi Shoji , Ohno Masatomi
Published: July 2006

cis-Chrysanthemaldehyde isomerized cleanly to the trans-isomer catalyzed with methoxydimethylsulfonium iodide (8) at 25 °C. Zinc halides as well as silica gel were also demonstrated to be effective catalysts. Related aldehydes and ketones isomerized also with 8 at 80 °C but dihydrochrysanthemaldehyde did not isomerize at all.
An Application of Microwave Treatment to the Dehydration of Manganese Dioxide for Lithium Nonaqueous Cells
Authors: Hirai Taketsugu , Tari Isao , Ohzuku Tsutomu
Published: July 2006

A new dehydration technique of manganese dioxide using 2.45 GHz microwave is presented. The so-called γ and γ,β-MnO2, each containing less than 1 wt% water, which are not attainable by heat, treatment, are obtained under specified conditions by this dehydration technique.
Structural Studies of Asymmetric Hydrogenation. V. The Crystal Structures of [(S)-1-Cyanoethyl][(S)(−)-α-methylbenzylamine]bis(dimethylglyoximato)cobalt(III) at 293 K and 173 K
Authors: Ohashi Yuji , Sasada Yoshio , Takeuchi Seiji , Ohgo Yoshiaki
Published: July 2006

The structure of [(S)-1-cyanoethyl][(S)(−)-α-methylbenzylamine]bis(dimethylglyoximato)cobalt(III) has been determined by X-ray analysis at 293 K and 173 K. The crystal is monoclinic, the space group being P21, Z=2, with a=8.768(2), b=13.356(2), c=9.538(3) Å, and β=96.73(3)° at 293 K, and a=8.617(4), b=13.222(4), c=9.517(7) Å, and β=96.26(7)° at 173 K. The structure was deduced by the heavy-atom method and was refined by the block-diagonal least-squares method to the final R values of 0.051 and 0.060 for 1878 and 1848 observed reflections at 293 K and 173 K respectively. The bis(dimethylglyoximato)cobalt moiety is twisted in the opposite way from that of [(R)-1-cyanoethyl][(S)(−)-α-methylbenzylamine]bis(dimethylglyoximato)cobalt(III). This supports the proposal that the asymmetry of the optically active amine is transferred into the substrate through the twist of the bis(dimethylglyoximato) cobalt moiety in the step of the σ-bond formation.
Neutron Diffraction Study of Liquid Acetyl Chloride
Authors: Ohtomo Norio , Arakawa Kiyoshi
Published: July 2006

The structure factor Sm(Q) for liquid acetyl chloride at room temperature has been determined in the range Q, 0.9–27 Å−1, by means of the time-of-flight (TOF) neutron diffraction method using the electron linear accelerator (LINAC). The structural parameters of CD3COCl, bond distances, bond angles, and rms amplitudes, in liquid phase have been determined by a comparison of calculated curves with observed data, and it has been concluded that a molecule within the liquid takes an essentially identical conformation as a rotational isomer with that in gaseous phase, which was determined by microwave spectroscopy.
Studies on the Aqueous Solutions of Guanidinium Salts. XIV. Effect of Guanidinium Bromide on the Surface Tension of Aqueous Solutions of the Cationic Surfactants
Authors: Miyajima Koichiro , Yoshida Hiromitsu , Maetani Junko , Nakagaki Masayuki
Published: July 2006

The surface tensions of decyl-, tetradecyl-, and hexadecyl-trimethylammonium bromides were measured in the aqueous solutions of potassium bromide (KBr) and guanidinium bromide (GuBr). The critical micelle concentrations (CMC’s) of the above surfactants decreased with increase of the concentration of KBr, while the CMC’s showed minimum values in the aqueous GuBr solution, as the concentration of GuBr increased. The Langmuir coefficient, KC, increased with decrease of the CMC. The influence of the salts on the surface tension and the micellization were well described in terms of the activity of the surfactant calculated by combining the Debye-Hückel law and Setschenow’s equation.
Selective Ester-exchange Reactions of Dibenzyl-aspartate and -glutamate in the Coordination Sphere of Copper(II) Ion
Authors: Nakao Yasuo , Demichi Masaaki , Nakahara Akitsugu
Published: July 2006

Copper(II) complexes of the Schiff bases derived from salicylaldehyde and dibenzyl aspartate or glutamate have been prepared for the first time. Upon refluxing the solution of these complexes in methanol for 30 min, bis(α-methyl β-benzyl N-salicylideneaspartato)copper(II) and bis(α-methyl γ-benzyl N-salicylideneglutamato)copper(II) were obtained. The mechanism of these selective ester-exchange reactions in the metal-coordination sphere has been discussed. Several Schiff bases were obtained and characterized.
Diastereomers and Circular Dichroism Spectra of the Tris(trans-1,2-cyclopentanediamine)cobalt(III) Complex
Authors: Kunimatsu Mihoko , Kanno Hideaki , Kojima Masaaki , Kashiwabara Kazuo , Fujita Junnosuke
Published: July 2006

The (lel3), (lel2ob), and (lelob2) isomers of [Co(rac-cptn)3]3+ were obtained by the reaction of trans-[CoCl2(pyridine)4]+ with rac-cptn, where cptn denotes trans-1,2-cyclopentanediamine. No indication for the formation of the (ob3) isomer was found. The isomers were resolved into optical isomers by SP-Sephadex column chromatography. The circular dichroism spectra of these optical isomers were measured and the results compared with those of the related complexes. The anomalous circular dichroism pattern of the (lel3) isomer in the region of the first absorption band was found to result from the contribution of the strong vicinal effect of the chiral cptn chelate ligand as compared with that of the configurational effect.
Kinetics and Mechanism of the Reactions of Bis(acetylacetonato)-palladium(II) with Alkylamines
Authors: Matsumoto Shinichi , Kawaguchi Shinichi
Published: July 2006

The reactions of bis(acetylacetonato)palladium(II), Pd(acac)2, with alkylamines (L) such as butyl-, cyclohexyl-, diethyl-, and dipropylamines in methanol to afford [Pd(acac)L2](acac) obey the usual two-term rate law, rate=(k0+k1[L])[Pd(acac)2]. On the other hand, the rate of reaction of Pd(acac)2 with diethylamine in THF and benzene is expressed by rate=(k1+k2[L])[L][Pd(acac)2]. A mechanism is proposed which presumes the hydrogen-bonding interaction of Pd(acac)2 with methanol and amine. Intermediacy of Pd(acac)(acac-C3)L in these reactions was denied on the basis of the kinetic studies, and the carbon-bonded complex was concluded to be produced via [Pd(acac)L2](acac). The equilibrium constants for the reactions, Pd(acac)2+2Et2NH\ightleftarrows[Pd(acac)(Et2NH)2(acac) and Pd(acac)(acac-C3)(Et2NH)+Et2NH\ightleftarrows[Pd(acac)(Et2NH)2](acac) were determined in dichloromethane and methanol.
Stereoselective Association between Acetylacetonatobis(ethylenediamine)cobalt(III) and Malonate Ions as Studied by Nuclear Magnetic Resonance
Authors: Nakazawa Hiroshi , Sakaguchi Ushio , Yoneda Hayami
Published: July 2006

The effect of added malonate upon the chemical shift and the exchange rate of amine hydrogens of acetylacetonatobis(ethylenediamine)cobalt(III) ion, [Co(acac)(en)2]2+, have been investigated by 1H and 13C NMR spectroscopy. In the absence of malonate, the amine groups give rise to two signals in the 1H spectra and two rate constants of amine exchange due to trans and cis (to coordinated oxygen) amine groups. Upon addition of malonate, the trans NH2 undergoes a down-field shift, the cis NH2 resonance splitting into two peaks. In the presence of malonate, all of the four kinds of amine hydrogens of [Co(acac)(en)2]2+ exhibit different exchange rates. The following conclusion was obtained from the results coupled with 13C NMR data, (i) The malonate ion works in two ways in amine exchange, as a general base catalyst and to form an exchange-inert ion-pair, (ii) The two trans hydrogens that are directed approximately parallel to the two-fold axis of the complex ion hydrogen-bond simultaneously to the two carboxyl groups of malonate, leading to a retardation of amine exchange rates. (iii) The rates of the other trans hydrogens and cis hydrogens are determined by a compromise between acceleration due to general base catalysis and deceleration due to forming ion-associated species, (iv) The conformation of coordinated ethylenediamine is fixed as either (δδ) or (λλ) in the hydrogen-bonded species.
Thermal Square Planar-to-Octahedral Transformation of Nickel(II) Complexes Containing 2-Aminobenzimidazole in the Solid Phase
Authors: Ihara Yoshinori , Tsuchiya Ryokichi
Published: July 2006

Thermal reactions of the complexes, [Ni(abi)4]X2·nH2O (abi, 2-aminobenzimidazole; X, Cl, Br, I, NO3, ClO4, or 1/2SO4; n, 3 for chloride and bromide, 1 for nitrate, and 0 for others) were investigated. Distinct color changes from orange to green were observed in the three complexes of chloride, bromide, and nitrate upon heating. It was found from the changes in absorption and far-IR spectra and magnetic susceptibilities under the thermal reactions that the complexes undergo transformation from square planar to tetragonally distorted octahedral structures, involving an increase in the coordination number from four to six. No such transformation could be found in the corresponding iodide, perchlorate, and sulfate. The effect of the introduced amino group on the structural conversion reactions of the abi complexes is discussed as compared with the corresponding benzimidazole complexes, [Ni(bimd)4]X2, which underwent transformation from square planar to octahedral structure upon heating when X is I or NO3.
New Synthesis and Hydroboration of Vinylphosphonates
Authors: Yamashita Mitsuji , Kojima Mitsumasa , Yoshida Hiroshi , Ogata Tsuyoshi , Inokawa Saburo
Published: July 2006

The Arbuzov reaction of trimethyl and triethyl phosphites with acyl chlorides gave 1-oxoalkylphosphonates in 57–80% yields. The Wittig reaction of the phosphonates with methylenetriphenylphosphorane gave vinylphosphonates in 25–59% yields. Hydroboration of vinylphosphonates in oxolane gave 2-hydroxyethylphosphonates in 50–65% yields. The procedure seems to be a good synthetic method to afford 1-alkyl-substituted 2-hydroxyethylphosphonates which have one more carbon atom than the starting 1-oxoalkylphosphonates.
Studies of Polymeric Flocculants. XI. The Preparation and Properties of Polyampholytes
Authors: Nonaka Takamasa , Egawa Hiroaki
Published: July 2006

The polyampholytes were prepared by treating potassium polymethacrylate with (3-chloro-2-hydroxypropyl)trimethylammonium chloride. The solution viscosity behavior and the potentiometric titration of the polyampholytes were studied. The flocculating ability of the polyampholytes was also investigated by the use of kaolin suspensions. The amine/acid ratio could be varied as desired to some extent by means of changing the reaction temperature. However, the polyampholytes containing more amino groups than about 46% could not be obtained. The resulting polyampholytes showed characteristic viscosity behavior. The results of the flocculation of kaolin suspensions with the polyampholytes showed that the polyampholytes can be expected to become a new type of polymeric flocculants, in which the chain expansion and the charge sign can be varied by changing the pH values of the solutions.
The Reaction of 2-Chloroazulene Derivatives with Lithium Acetylide in Liquid Ammonia
Authors: Morita Tadayoshi , Fujita Taira , Takase Kahei
Published: July 2006

The reaction of diethyl 2-chloroazulene-1,3-dicarboxylate (1a) with lithium acetylide in liq ammonia gave diethyl 4- and 6-ethynylazulene-1,3-dicarboxylates by an abnormal substitution reaction. In a similar manner, some 2-chloroazulenes, possessing alkoxycarbonyl and/or cyano substituents at the 1- and 3-positions of azulene nucleus, gave the corresponding 4 (or 8)- and 6-ethynylazulenes. The same type reaction proceeded when lithium phenylacetylide, sodium indenide, and sodium fluorenide were used as the reagents, 1a giving diethyl 4- and 6-(phenylethynyl)-, 6-(3-indenyl)-, and 6-(9-fluorenyl)azulene-1,3-dicarboxylates, respectively.
Heterofulvalenes. II. Synthesis and Reaction of 2,3 : 7,8-Dibenzo-1,4-dithia-6-azafulvalene
Authors: Nakayama Juzo , Imura Mimiko , Hoshino Masamatsu
Published: July 2006

Reaction of 2-isopentyloxy-1,3-benzodithiole with indole in acetic acid gave a 93% yield of 3-(1,3-benzodithiol-2-yl)indole (4a) which was converted to 2-(3-indolyl)-1,3-benzodithiolylium tetrafluoroborate (5a) in a 77% yield by treatment with trityl tetrafluoroborate. 5a was also prepared by reaction of indole with 2 molar amounts of 1,3-benzodithiolylium tetrafluoroborate. Treatment of 5a with triethylamine afforded the title compound 6a in 93% yield. 6a was protonated, methylated, and benzoylated at its 6-position by tetrafluoroboric acid, methyl iodide, and benzoyl chloride, respectively. Reaction of 6a with dimethyl acetylenedicarboxylate gave a 1,6-dipolar intermediate which was trapped as an adduct with ethanol. 6a was smoothly reduced by sodium borohydride to give its 5,6-dihydro derivative.
Studies on 1-(Thiosulfinylaminothio)piperidines
Authors: Morimura Syoji , Horiuchi Hideo , Tamura Chihiro , Yoshioka Takao
Published: July 2006

Hindered piperidine derivatives with a new functional group (–S–N=S=S), 2,2,6,6-tetramethyl-1-(thiosulfinylaminothio)piperidines (4) were obtained from the corresponding piperidines 1, sulfur monochloride and ammonia. These compounds were also prepared from bis(2,2,6,6-tetramethylpiperidino) disulfides or bis(2,2,6,6-tetramethylpiperidino) trisulfides under similar reaction conditions. In much lower yields, unhindered 1-(thiosulfinylaminothio)piperidines (8) were also obtained. The photochemical and thermal stabilities of 4 and 8 were nearly the same. Reaction pathways were disucssed.
The Electronic Spectra of Intramolecular Charge-transfer Compounds and Their Marked Solvatochromism in a Strong Hydrogen-bonding Solvent: 2-(Arylmethylene)-1,3-indandiones and 2-(1-Naphthyl)-p-benzoquinone
Authors: Chiba Kazuhiko , Aihara Jun-ichi , Araya Kotaro , Matsunaga Yoshio
Published: July 2006

The first electronic absorption bands of the title compounds can all be assigned to the intramolecular charge-transfer transitions. The solvent effects on these bands are quite analogous to those on the absorption bands characteristic of binary charge-transfer complexes. Especially, when the title compounds are dissolved in trifluoroacetic acid, marked bathochromic shifts of the first bands are observed, in harmony with their charge-transfer character. Such solvatochromism is obviously due to the hydrogen-bond formation between the solute and the solvent molecules. When strong hydrogen bonding occurs, the electron affinity of the 2-methylene-1,3-indandione moiety increases by about 0.41 eV.
A Conductance Study of the Complexation Reaction of Dibenzo-24-crown-8 with Alkali Metal Ions in Propylene Carbonate and Methanol
Authors: Takeda Yasuyuki , Yano Hisao
Published: July 2006

The formation constants (KML+) for 1: 1 complexes of dibenzo-24-crown-8 (DB24C8) with alkali metal ions (Na+, K+, Rb+, and Cs+) in propylene carbonate (PC) and methanol have been determined conductometrically at different temperatures in order to obtain the values of the enthalpy (ΔH) and entropy changes (ΔS). The complexation reactions between DB24C8 and the alkali metal ions in PC and methanol are all exothermic, and the ΔS values of these systems are all negative. In the case of the PC system, there is no considerable difference in ΔS among the alkali metal ions (Na+, K+, Rb+, and Cs+); thus, the KML+ sequences depend entirely on the −ΔH sequences. Since, in methanol, the −ΔH and −ΔS values for K+ are nearly equal to those for Cs+, and since the largest −ΔH value for Rb+ is balanced by the largest −ΔS value, DB24C8 shows no selectivity for the alkali metal ions (K+, Rb+, and Cs+) in methanol.
Stereochemistry of Base-catalysed Addition of Methyl Mercaptoacetate to Acetylenic Ketones and Esters. Effects of Activating Groups and Solvents
Authors: Basyouni Mohamed Nabih , Omar Mohamed Tawfik , Ghali Edwar Amin
Published: July 2006

Piperidine-catalysed addition of methyl mercaptoacetate to benzoyl- and p-chlorobenzoyl-phenylacetylenes in ethanol gave the corresponding (Z)-1-aryl-3-(methoxycarbonylmethylthio)-3-phenyl-2-propen-1-one. However, p-anisoylphenylacetylene gave a mixture of (Z)- and (E)-3-(methoxycarbonylmethylthio)-1-(p-methoxyphenyl)-3-phenyl-2-propen-1-ones in the ratio of 4:1. This ratio was completely inverted when the latter addition was carried out in dry benzene. Rationalisation of these results is presented which depends on the effect of activating groups and solvents on the stereochemistry of addition. Piperidine-catalysed addition of methyl mercaptoacetate to methyl phenylpropiolate in ethanol gave methyl (Z)-3-(methoxycarbonylmethylthio)cinnamate. Hydrazine hydrate converted some of the above mono-adducts into some pyrazole derivatives.
NMR Studies of Zerovalent Metal π-Complexes of Dibenzylideneacetone. III. Conformation and Bonding of the Mononuclear Palladium and Platinum Complexes
Authors: Tanaka Hisao , Kawazura Hiroshi
Published: July 2006

1H-NMR spectorscopy of the M[(C6H5CH=CH)2CO]3 (M=Pd,Pt) complexes revealed that the coordinated olefinic moieties are fixed in the s-trans form, while the uncoordinated ones are fluxional around the s-cis form. The fluxional behavior of the uncoordinated olefins was explained in terms of the π-back donation in the complexes.
The ENDOR Spectrum of 1,7,7-Trimethylbicyclo[2.2.1]heptane-2,3-dione Semiquinone in Solution
Authors: Tosa Reiko , Kotake Yashige , Okazaki Masaharu , Shikata Hideo , Kuwata Keiji
Published: July 2006

The ENDOR spectra of 1,7,7-trimethylbicyclo[2.2.1]heptane-2,3-dione semiquinone (camphorsemiquinone anion) showed a sharp temperature variation in the intensity of each ENDOR line. The relationship between the optimum temperature for the ENDOR enhancement and the relaxation mechanisms was discussed on the basis of the experimental results.
The Crystal Structures of Monoclinic and Triclinic Forms of Bis[(R)-1,2-propanediame]platinum(II) Chloride Dihydrate
Authors: Maeda Choji , Matsumoto Keiji , Ooi Shun’ichiro
Published: July 2006

The crystal structures of monoclinic and triclinic forms of [Pt(R-pn)2]Cl2·2H2O have been determined from diffractometer data. Despite the difference in crystal systems, the complex cations in the two kinds of crystals have essentially the same structure. The disposition of the CH3 groups is trans. One of the chelate rings is of the λ conformation, with an equatorial CH3 group, while the other has the δ conformation, with an axial CH3 group.
Studies on the Solvent Extraction of Metal Perchlorates. I. Partition of Sodium(I) between Aqueous Perchlorate, Thiocyanate, and Iodide Solution and Hexane Containing Trioctylphosphine Oxide
Authors: Kusakabe Satoshi , Sekine Tatsuya
Published: July 2006

Extraction equilibria of sodium (I) in aqueous 1 mol dm−3 sodium salt-hexane containing trioctylphosphine oxide systems were measured at 25 °C. The extracted species was always trisolvate, the extraction being improved in the order NaClO4>NaSCN>NaI>NaNO3. This is explained in terms of the hydrofobic and hydrophilic tendencies of the anions.
The Copper(I) Iodide-assisted Reaction of Nonactivated Aryl Iodides with Some Alkali Metal Pseudohalides
Authors: Suzuki Hitomi , Miyoshi Keiko , Shinoda Misao
Published: July 2006

Copper(I) iodide dissolves into warm hexamethylphosphoric triamide to give a black solution, in which polymethylated iodobenzenes undergo nucleophilic attack by azide and selenocyanate ions, giving the corresponding aryl azides and selenocyanates in low to good yields. In the absence of copper(I) salt, however, the reaction does not take place. Cyanide, cyanate, thiocyanate, and fluoride ions bring about a decoloration of the reaction mixture and no displacement reactions ensue, while the tellurocyanate ion affords the corresponding aryl cyanides while liberating elemental tellurium.
Studies on Heterocyclic Analogs of Azulene. VII. Regioselective Cycloadditions of Cycloheptimidazole to Electron-deficient Olefins
Authors: Abe Noritaka , Nishiwaki Tarozaemon
Published: July 2006

Cycloheptimidazole reacted with electrondeficient olefins (e.g., ethyl acrylate or acrylonitrile) to give the regioselective [6+2] cycloadducts, which were readily dehydrogenated to give 2a,3-dihydro-1,2a-diazacyclopent[cd]azulenes.
Photochemical Reductive Acylation and Oxidative Acyl Activation on Phenazine and Related Nitrogen Heterocycles
Authors: Takagi Makoto , Goto Setsuo , Matsuda Tsutomu
Published: July 2006

Irradiation of phenazine in acetaldehyde or propionaldehyde solution gave an N-acylated 5,10-dihydrophenazine. Acridine similarly gave 9-acyl-9,10-dihydroacridine, and 10-methylacridinium salt gave 9-acyl-10-methyl-9,10-dihydroacridine. In methanol N-acylated dihydro-phenazines reacted with N-bromosuccinimide to give phenazine and methyl car boxy lates in quantitative yield.
Synthesis of 1,6-Dioxadispiro[2.0.4.4]dodecan-7-one
Authors: Kakiuchi Kiyomi , Hiramatsu Yasuhiro , Tobe Yoshito , Odaira Yoshinobu
Published: July 2006

1,6-Dioxadispiro[2.0.4.4]dodecan-7-one, a useful intermediate of dispiro-α-methylene-γ-butyrolactones, was synthesized in a good overall yield by the cycloaddition of dichloroketene to 1,2-dimethylenecyclohexane, and the zinc dust reduction of the chlorine atoms, followed by the Baeyer-Villiger oxidation with m-chloroperbenzoic acid.
Determination of Stoichiometry and Formation Constant of Molecular Complexes by Differential Refractometry
Authors: Sahai Ram , Singh Vinod
Published: July 2006

A more adequate method has been proposed to determine the stoichiometry and equilibrium constant of molecular complexes by Job method using differential refractometry in modification of Yoshida and Osawa method. This method has been verified on phenol-naphthalene system in cyclohexane at 35 °C. The equilibrium constant (K1=4.9±0.20 dm3 mol−1), obtained by this method is in good agreement with the literature value.
Studies on Complexes of Metal(II) Carboxylates with Donor Molecules. IV. Complexes of Nickel(II) Chloroacetates with Pyridine N-Oxides and Triphenylphosphine Oxide
Authors: Kumar Narsingh , Kachroo Piyara Lal , Kant Rama
Published: July 2006

Twelve green crystalline complexes with the general formula [Ni(O2CR)2·L]2 were prepared by the reaction of stoichiometric amounts of pyridine N-oxide, 2-methylpyridine N-oxide, 3-methylpyridine N-oxide, and triphenylphosphine oxide with nickel(II) mono-, di-, and trichloroacetates in methanol. The complexes were characterized by elemental analyses, conductance, magnetic moments, IR and electronic spectra as neutral, binuclear, carboxylato bridged species identical to those of copper(II) acetate monohydrate. The complexes involve varying degrees of magnetic interaction which diminishes with increasing chlorine substitution in the chloroacetate moiety.
Correlation Functions Calculated by Using Reference Interaction Site Model Equations for Diatomic Molecular Fluids
Authors: Kojima Kazumitsu , Arakawa Kiyoshi
Published: July 2006

The reference interaction site model (RISM) theory was applied to diatomic molecular fluids, by using three different forms of approximation for site-site direct correlation function. Applicability of the three forms of RISM equation, RISM-1, RISM-2, and RISM-3, was examined, site-site pair correlation functions being calculated from them and a comparison of the results with those of computer simulations being made. Structure factor for liquid nitrogen, oxygen, and bromine were obtained from the solution of the RISM-2 equation and compared with experimental results.
Reactions of Pentane and 2-Methylbutane over Solid Super Acids Prepared by Different Conditions
Authors: Takahashi Osamu , Yamauchi Takashi , Sakuhara Toshihiko , Hattori Hideshi , Tanabe Kozo
Published: July 2006

The reaction of pentane to 2-methylbutane was carried out at 0 °C over solid super acid catalysts which were prepared by treatment of various metal oxides with SbF5 under different conditions, and the preparation conditions that affect the catalytic behavior of the catalyst were examined. Among the different base metal oxides, TiO2–ZrO2 became the most active catalyst when treated with SbF5. The maximum conversion to 2-methylbutane which appeared in the reaction of pentane was high when a base metal oxide was treated with SbF5 at a low temperature, and also when the reaction temperature was low. At the maximum conversion, the selectivity of the catalysts for the skeletal isomerization was almost 100%. As the reaction of pentane proceeded, the catalytic activity for the skeletal isomerization to 2-methylbutane was decreased but that for the formation of 2-methylpropane from 2-methylbutane was increased. The reaction mechanism is briefly discussed.
Studies of the Interaction of Poly(ethylene oxide) with Sodium Dodecyl Sulfate by Gel Filtration
Authors: Sasaki Tsunetaka , Kushima Kaoru , Matsuda Kazunori , Suzuki Hitoshi
Published: July 2006

The interaction between poly(ethylene oxide) (PEO), with a molecular weight of 6000, and sodium dodecyl sulfate (SDS) was studied by the gel-filtration method. The elution curve of the PEO–SDS system showed a tail of the elution volume smaller than that of SDS micelles at a concentration larger than about 4 mmol dm−3. This suggests that the PEO–SDS (PS) complex is formed in the system. The dissolution-state diagram in the presence of PEO was then constructed in which the fractions of SDS single ions, SDS micelles, and the PS complex were shown against the SDS concentration. For a constant concentration of PEO, the molecular weight of the PS complex increased with the increase in the concentration of SDS up to the CMC of the PEO–SDS system, beyond which it became constant. The molecular weight of the PS complex was estimated to decrease from 21000 at 0.025 wt% PEO to 15000 at 0.2 wt% PEO.