bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Incorporation of Dicarboxylates into Octacalcium Bis(hydrogenphosphate) Tetrakis(phosphate) Pentahydrate
Authors: Monma Hideki 
Published: July 2006

Abstract
Octacalcium bis(hydrogenphosphate) tetrakis(phosphate) pentahydrate (OCP) has been found to complex with saturated aliphatic dicarboxylate ions, CnH2nC2O42−; n=1–6. These organic substances were incorporated, instead of HPO42−, into the “B-layer” of the OCP structure. The incorporation caused expansion in the basal spacing (d100) of OCP from 18.7 Å to 19.6–26.1 Å. A possible structural model is proposed for the incorporation.
Catalytic Conversion of Allylic Esters to Corresponding Allylic Silanes with Hexamethyldisilane and Palladium(0) or Rhodium(I) Complexes
Authors: Urata Hisao , Suzuki Hiroharu , Moro-oka Yoshihiko , Ikawa Tsuneo 
Published: July 2006

Abstract
Treatment of allylic esters (R1CH=CR2CH2OCOR3: R1=H, Ar; R2=H, alkyl; and R3=Me, Ph) with hexamethyldisilane in the presence of catalytic amounts of PdL4 (L=PPh3 or P(OPh)3) or RhCl(PPh3)3 gives the corresponding allylic silanes in the excellent yield.
A Convenient Synthesis of 3-Aminotropolone and Its Reactions with Orthoesters. Formation of 8H-Cyclohept[d]oxazol-8-ones
Authors: Imafuku Kimiaki , Furuya Miki , Jin Zhong-Tian 
Published: July 2006

Abstract
Schmidt reaction of 3-acetyltropolone gave 3-acetamidotropolone, which was hydrolyzed to afford 3-aminotropolone (3). The compound 3 reacted with orthoformate, orthoacetate, orthopropionate, and orthobenzoate to give the corresponding 2-substituted 8H-cyclohept[d]oxazole-8-one derivatives.
A Simple and Convenient Method for the Synthesis of Sulfones Using Polyethylene Glycols or Their Dialkyl Ethers as Solvents or Catalysts
Authors: Sukata Kazuaki 
Published: July 2006

Abstract
Various alkyl p-tolyl sulfones were prepared in good yields under mild conditions in the presence of polyethyene glycols or their dialkyl ethers as solvents or catalysts.
Synthetic Photochemistry. XXVII. An Efficient Synthesis of Deoxytrisporone by Photocycloaddition
Authors: Takeshita Hitoshi , Hatta Seiji , Hatsui Toshihide 
Published: July 2006

Abstract
Deoxytrisporone was synthesized from isobutene and methyl 2,4-dioxohexanoate to show the utility of the regioselective photocycloaddition of β-diketone for construction of polysubstituted cyclohexenones.
The 2H-Cyclohepta[b]furan-2-one Formation from 2,4-Dichloro-5-methoxytropone with Dimethyl Malonate and Methyl Acetoacetate
Authors: Takeshita Hitoshi , Mori Akira , Minami Tomoyoshi 
Published: July 2006

Abstract
2,4-Dichloro-5-methoxytropone afforded 3,5,6-trisubstituted 2H-cyclohepta[b]furan-2-one derivatives by condensation with dimethyl malonate and methyl acetoacetate in an exclusive ciné-condensation mode in various solvents.
Reactions of 3-Acetyltropolone Methyl Ethers with 1,2-Cyclohexanediamine
Authors: Sudoh Yasunori , Imafuku Kimiaki 
Published: July 2006

Abstract
3-Acetyl-2-methoxytropone reacted with 1,2-cyclohexanediamine (2) (a mixture of cis 60% and trans 40%) to give four cis-trans pairs of 6-acetyl-5H-1,2,3,4,4a,11a-hexahydrocyclohepta[b]quinoxaline (3), 6-acetyl-9-formyl-1,2,3,4,4a,5,10,10a-octahydrophenazine (4), 6-acetyl-1,2,3,4,4a,5,10,10a-octahydrophenazine (5), and 1-methyl-6H-6a,7,8,9,10,10a-hexahydropyrrolo[3,2,1-de]phenazine (6). The reaction of 2-acetyl-7-methoxytropone with 2 gave cis- and trans-N,N′-bis(6-acetyl-7-oxo-1,3,5-cycloheptatrienyl)-1,2-cyclohexanediamine, besides the above products. The cis- and trans-isomers of 4, 5, and 6 were secondary products from the cis- and trans-isomers of 3, respectively.
The Preparation of 1-Carbamoyl-3-cyanoguanidine and 1-Cyanobiuret from Cyanourea
Authors: Iio Kokoro 
Published: July 2006

Abstract
Cyanourea in an aqueous or organic solution which was allowed to stand at room temperature gave 1-carbamoyl-3-cyanoguanidine and 1-cyanobiuret. The reaction was promoted by a mixture of cyanourea and its alkali salt. 1-Cyanobiuret was also obtained quantitatively by the reaction of cyanourea with alkali cyanate.
Nonisothermal Kinetics of Crystal Growth from Preexisting Nuclei
Authors: Ozawa Takeo 
Published: July 2006

Abstract
Fundamental kinetic equations for nonisothermal crystal growth from preexisting nuclei are derived, by introducing a concept of reduced time. A method of kinetic analysis of thermoanalytical data of these processes is proposed, and all kinetic parameters can be estimated by the method, so that the process proceeding under various temperature changes can also be predicted.
The Structure of Liquid Alcohols by Neutron Diffraction. I. Molecular Structure of Methyl Alcohol
Authors: Tanaka Yukio , Ohtomo Norio , Arakawa Kiyoshi 
Published: July 2006

Abstract
The structure factor Sm(Q) for liquid methyl alcohol (CD3OD) at room temperature was obtained by means of the LINAC-TOF neutron diffraction method. An analysis of the diffraction data was carried out, and the molecular structure of CD3OD in liquid phase was determined as: the O–D, C–O, and C–D bond lengths are 0.990±0.010, 1.435±0.005 , and 1.085±0.005 Å, respectively. The O–D and C–D lengths were found to be longer than those values determined in gaseous phase.
ENDOR Study of Benzothiazolone Azine Cation Radicals by Means of a TM110 Mode Cavity
Authors: Lopez Javier , Yamauchi Jun , Okada Keiichi , Deguchi Yasuo 
Published: July 2006

Abstract
The electron nuclear double resonance (ENDOR) spectra of benzothiazolone azine cation radicals were observed by means of an ENDOR spectrometer equipped with a TM110 mode cavity. Highly diluted solutions of the radicals and a high radiofrequency power of 300 W facilitated the ENDOR observation. The obtained ENDOR values are different from the previously published results determined only from the ESR data, especially for the substituted alkyl groups. The assignment of the hyperfine coupling constants was made on the basis of the molecular orbital calculations as well as the re-examination of the ESR spectrum simulation. Good agreement between the calculated and the measured spectra is obtained if one assumes that the hyperfine coupling constants of the two different sets of nitrogen nuclei are equal as has been pointed out earlier.
Sodium Sulfate Doped with Sodium Vanadate and Rare Earth Sulfate as a Solid Electrolyte for a Sulfur Dioxide Gas Detector
Authors: Imanaka Nobuhito , Adachi Gin-ya , Shiokawa Jiro 
Published: July 2006

Abstract
Sodium sulfate doped with NaVO3 and Ln2(SO4)3 (Ln=Eu, Pr, and Y) show higher electrical conductivity for Na+ ions and maintains a high temperature phase, Na2SO4–I, without showing phase transformation. The electromotive force (EMF) using solid solutions, Na2SO4–NaVO3–Ln2(SO4)3 (Ln=Pr and Y), as solid electrolytes exhibits good agreement with the calculated value, the temperature as low as 673 K which is approximately 300 K lower than pure sodium sulfate can be.
Kinetics of the Conformational Change and Subunit Dissociation of Aldolase
Authors: Ohga Yoko , Nakanishi Mamoru , Tsuboi Masamichi 
Published: July 2006

Abstract
The kinetics of acid denaturation of muscle aldolase were examined by stopped-flow fluorescence and stopped-flow light scattering measurements. The denaturation reaction was found to consist of three distinguishable steps—step I with fluorescence increase only, step II with both fluorescence increase and light scattering decrease, and step III with fluorescence decrease alone. Circular dichroism and sedimentation equilibrium measurements were also made at different pH’s in the course of the acid denaturation. It was concluded that in the acid denaturation of this enzyme a rearrangement of the secondary or tertiary structures takes place rapidly (4 s−1 at 21.5 °C and at pH 3.4), and then the subunit dissociation occurs more slowly (0.04 s−1 at 21.5 °C and at pH 3.4), with further conformational change. The subunit dissociation was found to be caused by two H+ per tetramer.
Induction of the β-Form of Poly(S-carboxymethyl-l-cysteine) and Poly[S-(2-carboxyethyl)-l-cysteine] by Chromium(III), Iron(III), and Lanthanum(III) Chlorides
Authors: Oka Kazuki , Maeda Hiroshi , Ikeda Shoichi 
Published: July 2006

Abstract
The β-form was induced by the addition of CrCl3, FeCl3, and LaCl3 to the salt-free solutions of fully ionized poly(S-carboxymethyl-l-cysteine) (poly[Cys(CH2COOH)]) and poly[S-(2-carboxyethyl)-l-cysteine] (poly[Cys(CH2CH2COOH)]). The induction occurred below the equivalent point in both polypeptides. The inducing powers of the three trivalent cations were rather similar. They were weaker than Cu2+ ions in the case of poly[Cys(CH2COOH)], while they were comparable with Cd2+ ions in the case of poly[Cys(C2H4COOH)]. Cu2+ and Cd2+ ions were the most effective species among divalent cations in the induction of the β-form of poly[Cys(CH2COOH)] and Poly[Cys(C2H4COOH)], respectively.
Response Time Curves of Neutral Carrier Membrane Electrode of Tubular Shape
Authors: Degawa Hisao , Shinozuka Noriko , Hayano Shigeo 
Published: July 2006

Abstract
A tubular flow-through electrode system for measuring the response time curves under the step change of concentration using an ammonium ion-selective poly(vinyl chloride) membrane electrode was described. The response time data are analyzed by the curve fitting method using two theoretical equations, which are an exponential type equation based on an assumption of the film diffusion and a square root type one based on that of the diffusion within the membrane, and a semiempirical equation of hyperbolic type. A method of curve fitting in which the equilibrium potential is regarded as an unknown parameter was described in detail. The initial part of the response time curves, where the potential change is large, was fitted by the exponential type equation, while the following part close to the equilibrium potential was fitted by the square root type one. The semiempirical equation could also be fitted to the wide range of the curves. The dependence of the time constant of the exponential type equation upon the flow rate of sample solution is examined; the results firmly supports both the film diffusion as a determining process for the initial part of the curve and the reliability of the present experimental system.
Synthesis of [3](1,1′)[3](3,3′)- and [4](1,1′)[4](3,3′)Ruthenocenophanes
Authors: Kamiyama Shin-ichi , Kasahara Akira 
Published: July 2006

Abstract
[3](1,1′)[3](3,3′)- and [4](1,1′)[4](3,3′)Ruthenocenophanes were synthesized via cyclization of the propionic acid derivatives of [3](1,1′)- and [4](1,1′)ruthenocenophanes with polyphosphoric acid or trifluoroacetic anhydride, respectively. The 1H NMR, IR, and electronic spectra of these dibridged ruthenocenes were measured and compared with those of monobridged ruthenocenes.
The Reaction of Cyclic 1,3-Diketones with Alkylthiocydopropenium Ions to Yield 2-Alkylthio-substituted 2H-Pyrans
Authors: Yoshida Hiroshi , Nakajima Mikito , Ogata Tsuyoshi , Matsumoto Kiyoshi 
Published: July 2006

Abstract
This study treats the reactions of methylthio-, ethylthio-, or benzylthiodiphenylcyclopropenium ion (1) with 5-, 6-, and 7-membered cyclic 1,3-diketones, giving either 2-alkylthio-2H-pyrans or dienone derivarives. Treatment of 1 with 1,3-cyclopentanedione, 1,3-cyclohexanedione, 5,5-dimethyl-1,3-cyclohexanedione, 4-hydroxy-6-methyl-2-pyrone, 4-hydroxycoumarin, and 1,3-cycloheptanedione in the presence of triethylamine afforded 2-alkylthio-2H-pyrans. The structure of the products was elucidated on the basis of their elemental analyses, IR, 1H-NMR, 13C-NMR, and mass spectroscopic data, as well as chemical transformations. 2-Alkylthio-2H-pyrans with mercury(II) chloride in an alcohol underwent conversion to the corresponding 2-alkoxy-2H-pyrans. The 1H- and 13C-NMR data of these compounds clearly show that the equilibrium lies completely on the side of the 2H-pyran. In contrast, the reaction of 1 with 1,3-indandione yielded the ring-opened dienone derivative as a mixture of E and Z isomers.
An Electrochemical Study on Anion Doping-Undoping Process of Polyacetylene by Means of FFT Impedance Measurement
Authors: Osaka Tetsuya , Kitai Takashi 
Published: July 2006

Abstract
An electrochemical anion doping-undoping process of cis-polyacetylene, (CH)x, was investigated in 1 mol dm−3 LiClO4 or LiBF4 in propylene carbonate by the FFT impedance measurement. This could be applied to the system with time-variation because of its high speed measuring duration. The doping-undoping process of the anion was represented by the Randles-type equivalent circuit, considering the corrective term concerned with surface roughness. The impedance behavior of the doping-undoping process was pursued by the variation of resistive component, Rr. The value of Rr was mainly reflected by the dopant concentration at the surface. The variation of Rr indicated that rapid or strong-drive doping produces non-uniformity of dopant distribution in the film and high dopant concentration at the surface.
Oxidation Potential of Intramolecular Exciplex on a Vinyl Copolymer as Estimated by Electron-transfer Quenching Reactions
Authors: Iwai Kaoru , Takemura Fukuo , Furue Masaoki , Nozakura Shun-ichi 
Published: July 2006

Abstract
In the electron-transfer reaction from the fluorescent intramolecular exciplexes of a copolymer containing phenanthrene and N,N-dimethylaniline moieties, and of a model compound to electron acceptors, the reactivity of the exciplexes was studied kinetically in polar and nonpolar media. The copolymer was poly(9-vinylphenanthrene-co-p-dimethylaminostyrene) and the model compound was N,N-dimethyl-4-[3-(9-phenanthryl)propyl]aniline. The oxidation potential of the exciplex was evaluated by the relation of the exciplex-quenching rate constants to the reduction potentials of electron-accepting quenchers according to the equations of Rehm and Weller. It was found that the electron-donating ability of these intramolecular exciplexes resembled with each other and was larger than that of excited phenanthrene. In polar media the donating ability was very close to that of the phenanthrene anion radical.
Oxygen- and Carbon Monoxide-binding Affinity of the Liposomal Heme under Semiphysiological Conditions
Authors: Tsuchida Eishun , Nishide Hiroyuki , Yuasa Makoto , Sekine Mikiya 
Published: July 2006

Abstract
Oxygen- and carbon monoxide-binding affinity (P1⁄2) of the [α,α,α,α-meso-tetrakis(o-pivalamidophenyl)porphinato]iron(II)-mono(1-dodecyl-2-methylimidazole) complex incorporated in liposome of phosphatidylcholine (abbreviated as liposomal heme) were measured in pH 7.0 aqueous solution at 15–37 °C. The P1⁄2(O2) and P1⁄2(CO) values at 37 °C were 49 and 0.02 mmHg, respectively. Enthalpy and entropy changes for the reversible bindings were similar to those of hemoglobin. The relationship between temperature and P1⁄2 for the dimyristoylphosphatidylcholine-liposomal heme had a breaking point at ca. 24 °C, which agreed with the phase transition temperature of the liposomal heme.
A New and Effective Synthetic Method for the Preparation of the Esters, Peptides, and Lactones Using 3-(5-Nitro-2-oxo-1,2-dihydro-1-pyridyl)-1,2-benzisothiazole 1,1-Dioxide. Synthesis of (±)-(E)-8-Dodecen-11-olide, Recifeiolide
Authors: Ahmed Alauddin , Taniguchi Nagahiro , Fukuda Hirohiko , Kinoshita Hideki , Inomata Katsuhiko , Kotake Hiroshi 
Published: July 2006

Abstract
3-(5-Nitro-2-oxo-1,2-dihydro-1-pyridyl)-1,2-benzisothiazole 1,1-dioxide(BID-NPy), readily prepared from 3-chloro-1,2-benzisothiazole 1,1-dioxide and 5-nitro-2-pyridone, proved to be a very useful condensing reagent. A variety of esters, dipeptides, and lactones were obtained in excellent yields. Furthermore, BID-NPy was successfully employed for the lactonization step in a new synthesis of a naturally occurring (±)-(E)-8-dodecen-11-olide, recifeiolide.
Intramolecular Cycloaddition of Two Acyl-1,4-benzoquinone Moieties on Photolysis
Authors: Miyagi Yo , Maruyama Kazuhiro , Tanaka Nobuo , Sato Mamoru , Tomizu Toshinori , Isogawa Yasuhiro , Kashiwano Hisae 
Published: July 2006

Abstract
Upon irradiation a regio- and stereoselective cycloaddition occurred intramolecularly between two acyl-1,4-benzoquinone moieties connected by a polymethylene bridge. The regio- and stereoselectivities are different from those of the corresponding intermolecular cycloaddition; this was interpreted in terms of the Diels-Alder reaction between an acyl-1,4-benzoquinone moiety and a photochemically produced dienol.
A Convenient Synthesis of 4-(2,2-Dichloroethenyl)-5,5-dimethyltetrahydro-2-furanone Derivatives, a Key Intermediate of Permethrinic Acid
Authors: Tsuboi Sadao , Amano Eiichiro , Takeda Akira 
Published: July 2006

Abstract
A key intermediate of 2-(2,2-dichloroethenyl)-3,3-dimethylcyclopropanecarboxylic acid, 3-alkoxycarbonyl(or acyl)-4-(2,2-dichloroethenyl)-5,5-dimethyltetrahydro-2-furanone was prepared by the base-catalyzed condensation of 2-methyl-3,5,5-trichloro-4-penten-2-ol with acetate derivatives such as malonic esters, acetoacetic esters, and benzoylacetate. The reactivity of 3-acetyl-4-(2,2-dichloroethenyl)-5,5-dimethyltetrahydro-2-furanone to an excess amount of thionyl chloride in ethanol was also examined. An analog, 5-butyl-4-(2,2-dichloroethenyl)-3-ethoxycarbonyl-5-methyltetrahydro-2-furanone was also prepared in 31% yield.
Syntheses of Aryl Glyoxylate. I. The Reaction of Alkyl Dichloro(alkoxy)acetates with Aromatics in the Presence of Lewis Acid
Authors: Itoh Osamu , Nagata Takayoshi , Nomura Isamu , Takanaga Tetsuya , Sugita Toshio , Ichikawa Katsuhiko 
Published: July 2006

Abstract
Ethyl dichloro(ethoxy)acetate (1) and methyl dichloro(methoxy)acetate (2) were characterized. The reaction of 1 and 2 with aromatics in the presence of AlCl3 gave a considerable yield of aromatic α-keto ester. The aromatics included mono- and polymethylbenzene and anisol. The reaction was studied under various conditions and the results were compared with the acylation by ethoxalyl or methoxalyl chloride. The reaction mechanism was also discussed.
Studies of Bitter Peptides from Casein Hydrolyzate. X. Synthesis and Bitter Taste of H–Arg–Gly–Pro–Phe–Pro–Ile–Ile–Val–OH Corresponding to C-Terminal Portion of β-Casein
Authors: Kanehisa Hidenori , Miyake Ichizo , Okai Hideo , Aoyagi Haruhiko , Izumiya Nobuo 
Published: July 2006

Abstract
In order to ascertain the validity of the structure of bitter peptide BPIa (H–Arg–Gly–Pro–Pro–Phe–Ile–Val–OH) isolated from casein hydrolyzate by Minamiura et al., the C-terminal octapeptide of β-casein (H–Arg–Gly–Pro–Phe–Pro–Ile–Ile–Val–OH) determined by Ribadeau Dumas et al., which is assumed to correspond to BPIa, was synthesized and compared with the synthetic BPIa which was confirmed to be identical with the natural one. The two synthesized peptides, however, did not match on thin-layer chromatography. The result indicates that the structure of BPIa need not be converted to Ribadeau Dumas’ formula. The octapeptide possessed an extremely bitter taste, with a threshold value of 0.004 mM (1 M=l mol dm−3). It is the most bitter peptide.
Interactions between Anionic Surfactants and Oil Dyes in the Aqueous Solutions. III. Thermochromism in the Presence of Surfactant Micelle and Dye–Surfactant Complexes
Authors: Abe Masahiko , Ohsato Mitsuo , Suzuki Nobuyuki , Ogino Keizo 
Published: July 2006

Abstract
The interactions between 4 anionic surfactants and 3 azo oil dyes have been studied by a spectrophotometer. The spectrographic behavior of these solutions was dependent on the kinds of hydrophilic groups in each surfactant and the kind of auxochrome in the azo oil dyes. In particular, a sulfate and two sulfonates including strongly hydrophilic groups interacted strongly with the oil dyes (4-NH2) which have an amino group at 4-position of naphthalene. At lower concentrations, an isosbestic point was recognized; this occurred because of the formation of the hydrophobic dye–surfactant complex (1:1). In the neighborhood of the cmc region, the spectrum with a peak at 520 nm changed with temperature into another one with a 440 nm band; this is the so-called thermochromism. This may be attributed to the fact that, in the presence of surfactant micelles, the 4-NH2 exhibits an azo form at higher temperature, but a resonance stabilized azonium form is found at lower temperature.
Structural Characterization of Soluble Products from a Series of Reductively Butylated Coals Prepared in Refluxing Tetrahydrofuran
Authors: Miyake Mikio , Sukigara Masayuki , Nomura Masakatsu , Kikkawa Sh\={o}ichi 
Published: July 2006

Abstract
A series of butylated Y\barubari coals were prepared by an improved reductive alkylation method, and detailed structural parameters of respective solution products in pentane (PS) and benzene (BS) were estimated; this experimental procedure is likely to offer more insight into chemical structures of products and important factors effective for solubilization than any analyses on a single product. The PS and BS have average molecular weights of 700–800 and 1500–2050 and are composed of about two and more than five structural units, respectively. These values suggest that the BS molecule is quite large compared with the corresponding products obtained by other methods such as hydrocracking. On the other hand, the ring sizes of one structural unit of the respective products are roughly the same (about three rings). The BS materials are coal macromolecules with stackings loosened by introduction of alkyl groups, while the PS materials are products through cleavage of bonds connecting the structural units and through addition of so many alkyl groups as to increase the affinity for the solvent. In addition, an absence of intermolecular hydrogen bonds mainly due to OH groups contributes to quite a high solubility of the alkylated coals. Increase in BS yield accompanies an increase in aliphatic carbon ratio and polymerization degree and a decrease in size of aromatic ring systems. These results may be ascribed to the heterogeneity of coal constituents.
N,N′-Carbonyldi[2(3H)-benzoxazolethione]: New, Reactive Condensing Agent for the Synthesis of Amides, Esters, Peptides, and Polyamides
Authors: Ueda Mitsuru , Kawaharasaki Naomi , Imai Yoshio 
Published: July 2006

Abstract
A new condensing agent, N,N′-carbonyldi[2(3H)-benzoxazolethione] (3), was readily prepared by the reaction of 2-benzoxazolethiol and trichloromethyl chloroformate in benzene. The condensing agent 3 is shown to be useful for the preparation of amides, esters, and dipeptides under mild conditions. A successful polyamide synthesis by the polycondensation of isophthalic acid with diamines using 3 is also described.
The Electronic Structure of Heterotropones. Photoelectron Spectra and Molecular Orbital Calculations
Authors: Gleiter Rolf , Bischof Peter , Böhm Michael C , Guilard Roger , Yamaguchi Hiroyuki 
Published: July 2006

Abstract
Using a helium discharge lamp with an energy of 21.21 eV (He(I)α line) the photoelectron (PE) spectra of the heterotropones 1–7 have been investigated and compared with the PE spectra of benzologue tropones and with the PE data of thiophene, furan and pyrrole. The first five ionization events in the PE spectra of 1 to 7 could be assigned to electron ejections from 2a2(π), 4b1(π), 9b2(n), 3b1(π), and 1a2(π) orbitals. This assignment has been deduced by means of experimental correlation techniques and using ZDO calculations of the LCBO and HMO type as well as semiempirical SCF versions (MINDO/3 and PPP).
Ion Exchange Equilibria between Alkali Metals and Hydrogen Ions on Iron(III) Antimonate, an Inorganic Ion Exchanger
Authors: Rawat Jagdish Prasad , Singh Balbir 
Published: July 2006

Abstract
Ion exchange equilibria of alkali metal ions (Li+, Na+, K+ and Rb+)/H+ systems have been studied at 30, 40, 50, and 60 °C on iron(III) antimonate as a cation exchanger. The exchange isotherms have been measured for both forward and backward reactions with solutions of ionic strength 0.1 by the batch technique. The isotherms showed S-shaped curves for each exchange system except Li+/H+. Selectivity coefficients vary with the equivalent fraction (\barXM) of the alkali metal ions in the exchanger and give linear functions against \barXM in the range from 0–0.40. The selectivity sequence shows Na+&lt;Li+&lt;K+&lt;Rb+. The overall thermodynamic data are evaluated.