bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective α-Mono- and α,α-Dialkylations of 1,3-Diketones Using Solid Base Prepared from Sodium Ethoxide and Alumina
Authors: Yoshihara Nobutoshi , Kitagawa Teruhiro , Ihara Ikuko , Hasegawa Sadao , Hasegawa Tadashi
Published: July 2006

The alkylation of 1,3-diketones with alkyl halides using a solid base prepared from sodium ethoxide and alumina was carried out. The amount of 0.4 mol of sodium ethoxide on 50 g of alumina showed the best reactivity for alkylation. Selective mono- and dialkylation could be achieved by controlling the reaction temperature.
Photocatalytic Hydrogen Evolution from Aqueous Methanol Solution on Niobic Acid
Authors: Kudo Akihiko , Tanaka Akira , Domen Kazunari , Maruya Ken-ichi , Onishi Takaharu
Published: July 2006

Niobic acid powders, H3NbO4 and H8Nb6O19, obtained by hydrolysis from aqueous potassium niobate (K3NbO4 and K8Nb6O19) solutions with sulfuric acid showed a high photocatalytic activity for hydrogen evolution from an aqueous solution including methanol as a sacrificial reagent without supporting any other materials, such as Pt (quantum yield; ca. 10% at 330 nm). The activity depended on the calcination temperature. H3NbO4 powder dried at 380 K was the most active one. As the calcination temperature was increased, the H3NbO4 photocatalyst was transformed into HNbO3 (or Nb2O5·H2O) and Nb2O5 by dehydration. The BET surface area and the band gap of the powder decreased with the phase transformation. It is concluded that both the surface area and hydrated state strongly affect the activity for sacrificial hydrogen evolution on the niobic acid photocatalysts.
Ru(6,6′-Diamino-2,2′-bipyridine)32+: Effect of Interligand Steric Strain on the Spectroscopic, Photochemical, and Electrochemical Properties of the Complexes
Authors: Araki Koji , Fuse Masahiro , Kishii Noriyuki , Shiraishi Shinsaku
Published: July 2006

Spectroscopic, photocehmical, and electrochemical properties of a series of the Ru(II) complexes 1–4, Ru(dabp)3−n(bpy)n(BF4)2 (n = 0, 1, 2, and 3, respectively, dabp = 6,6′-diamino-2,2′-bipyridine, and bpy = 2,2′-bipyridine) having different degree of interligand steric strain caused by amino substituents of dabp were studied. Their metal-to-ligand charge transfer bands and oxidation-reduction potentials of a Ru(II)/Ru(III) couple were not so much different from each other. Though the complex 3 showed weak emission at around 630 nm (φ = 6 × 10−4), no emission of light was observed for the complexes 1 and 2. These properties and photoanation of the complexes 1 and 3 were discussed in terms of the steric and electronic effects of the amino substituents.
The Role of a Spin-Coupled Intermediate in a System Consisting of Tetraminecobalt(III) Complexes and Catechols –A Model Intermediate of Dioxygenase Reaction–
Authors: Nakashima Satoru , Ohya-Nishiguchi Hiroaki , Hirota Noboru , Tsuboyama Sei , Chijimatsu Tamiko
Published: July 2006

The reactions of two CoIII-tetramine (N4) complexes, cis-α-Dichloro(triethylenetetramine)cobalt(III) chloride = [CoIIICl2(trien)]Cl (1) and aquabromo[(2R, 5R, 8R, 11R)-2,5,8,11-tetraethyl-1,4,7,10-tetraazacyclododecane]cobalt(III) bromide = [CoIIIBr(Et4[12]-aneN4)(H2O)]Br2 (2) with 3,5-di-t-butylcatechol (H2dbc) have been examined by visible, NMR and ESR spectroscopies to elucidate the mechanism of the activation and the oxygenation of catechol by the complex formation. The reactions proceeded in a mixed solvent (H2O : MeOH = 1 : 1) at 50 °C in the presence and absence of dioxygen. NMR showed that the complexes react with E2dbc and dioxygen, and yield oxidatively cleavaged products. ESR measurements detected a CoIII-semiquinone (dbsq) radical and a high-spin CoII complex, regardless of the presence of dioxygen. Especially in the case of 1, the magnetic moment of the complex isolated from the anaerobic reaction solution, exhibited that there exists an antiferromagnetic spin-coupling between the high-spin (S= 3/2) CoII ion and the semiquinone radical in the complex. These results show that two species detected by ESR are in equilibrium with a high-spin CoII-dbsq binary complex formed by intramolecular electron transfer. It is conclusively clarified that the one-electron-transferred intermediate [CoII(N4)dbsq]+ is the activated intermediate, which introduces dioxygen into the semiquinone moiety.
Preparation of New Nitrogen-Bridged Heterocycles. 29. Reinvestigation on the Dehydrogenation Reaction of 5,5a-Dihydropyrido[2,1-c]thieno[3,2-e][1,4]thiazine Derivatives
Authors: Kakehi Akikazu , Ito Suketaka , Hakui Jun-ichi , Fukazawa Hiroaki
Published: July 2006

Reactions of the title compounds with 2,3-dichloro-4,5-dicyano-p-benzoquinone were reinvestigated; it was found that the corresponding products were not the ring-contracted and rearranged thieno[2,3-b]indolizines, as described previously by us, but were ordinary dehydrogenated compounds, pyrido[2,1-c]thieno[3,2-e][1,4]thiazines. In contrast with pyrido[2,1-c]thieno[3,2-e][1,4]thiazine derivatives which have no substituent or only one methyl group on the pyridine ring, their 6,8-dimethyl compounds could be smoothly converted by keeping them at room temperature or heating their ethanolic solution to the corresponding desulfurized or rearranged 6,8-dimethylthieno[2,3-b]indolizine derivatives in moderately to good yields. The structures of these pyrido[2,1-c]thieno[3,2-e][1,4]thiazines and thieno[2,3-b]indolizines were assigned mainly based on elemental analyses, and spectral inspections; X-ray analyses for two compounds finally confirmed the former structure, pyrido[2,1-c]thieno[3,2-e][1,4]thiazine.
Diels–Alder Reaction of (1-Methylene-2-propenyl)cobaloxime, 1-Methylene-2-propenyl-bis(dimethylglyoximato)pyridine-cobalt(III)
Authors: Tada Masaru , Shimizu Tamaki
Published: July 2006

(1-Methylene-2-propenyl)cobaloxime (1), a diene having a transition metal substituent, was prepared conveniently from 2-chloromagnesio-1,3-butadiene and chlorocobaloxime. Cobaloxime 1 gives Diels–Alder adducts with olefinic dienophiles (maleic anhydride, N-phenylmaleimide, p-benzoquinone, dimethyl fumarate, methyl vinyl ketone, and methyl acrylate) and acetylenic dienophiles (methyl propiolate and dimethyl acetylenedicarboxylate). The reactivity of cobaloxime 1 is higher than that of its metalloid analogs, such as 2-silyl-, 2-seleno-, and 2-stannyl-1,3-butadiene, though the reaction pattern is essentially the same. This additional activation of the diene system by cobaloxime is accounted for by a back donation of the filled d-orbital of cobalt(III) to the π-system of the diene.
Hydroacylation of Alkyl Vinyl Ketones and Acrylic Esters Using Organotetracarbonylferrates. Synthesis of 1,4-Dicarbonyl Compounds
Authors: Yamashita Masakazu , Tashika Haruyoshi , Uchida Masaya
Published: July 2006

Alkyl vinyl ketones and acrylic esters were hydroacylated with organotetracarbonylferrates to the corresponding 1,4-diketones and 4-oxo carboxylic acid derivatives in good yield in dipolar aprotic solvents such as N,N-dimethylacetamide. Addition of 18-crown-6 improved the yield. cis-Jasmone and γ-jasmolactone were synthesized by use of these reactions.
Synthesis of Sperm Whale Myoglobin-(77–96)-Eicosapeptide and Circular Dichroism Spectra of the Related Peptides
Authors: Hashimoto Chikao
Published: July 2006

Sperm whale myoglobin-(91–96)- (6a), -(85–90)- (7a), -(77–84)- (8), -(85–96)- (9a), and -(77–96)- (10) peptides were prepared. The products, derived from protected myoglobin-(91–96)-, -(85–90)-, and -(85–96)-peptides, partly changed into peptides containing a pyroglutamic acid residue in the course of purification by various forms of column chromatography. The circular dichroism (CD) spectra of free peptides 6a, 7a, 8, 9a, and 10 in 0.10 M phosphate buffers at pH 4.00, 6.50, and 8.50 were not typical of the helical structure. However, the CD spectra of peptides 7a, 9a, and 10 in 60% 2,2,2-trifluoroethanol–0.10 M phosphate buffers at the same pHs showed profiles characteristic of a helical structure.
Efficient Selenation of Quinones: Synthesis of Novel Benzo[b]naphtho[2,3-e]selenintrione and Dibenzo[b,e]seleninone
Authors: Sakakibara Makoto , Toru Takeshi , Imai Takahiro , Watanabe Yoshihiko , Ueno Yoshio
Published: July 2006

Selenation of 2-bromonaphthoquinone with an areneselenolate ion generated from bis(2-methoxy-carbonylphenyl) diselenide, chlorodiphenylphosphine, and LiOH afforded 2-[(2-methoxycarbonylphenyl)seleno]-1,4-naphthoquinone from which 12H-benzo[b]naphtho[2,3-e]selenin-6,11,12-trione was synthesized. 1,4-Dimethoxy-2,3-dimethyl-10H-dibenzo[b,e]selenin-10-one was prepared starting from 6-bromo-2,3-dimethylbenzoquione through the selenation and cyclization steps.
A Flash Photolysis Study of CH4–O2 Mixtures behind Shock Waves: Examination of Reaction of CH3+O2
Authors: Ohmori Kenji , Yoshimura Masabumi , Koshi Mitsuo , Matsui Hiroyuki
Published: July 2006

ArF laser photolysis in the mixtures of CH4 and O2 highly diluted in Ar has been conducted behind reflected shock waves, where O and H atoms have been monitored using the ARAS technique. The rate constant for the reaction CH4 + O → CH3 + OH (1) has been directly determined to be 10−8.95 ± 0.27 exp [−(15.4 ± 2.0)kcal mol−1/RT] cm3 molecule−1 s−1 over the temperature range of 1365–1840 K. Also the consecutive reactions; CH3 + O2 → CH3O + O (3a) and CH3 + O2 → CH2O + OH (3b) have been examined more directly than in previous thermally initiated experiments, and the combinations of k3a and k3b have been evaluated at the temperature range from 1622 to 1840 K.
Stoichiometries and Equilibrium Constants of Cyclodextrin-Surfactant Complexations
Authors: Funasaki Noriaki , Yodo Hiromi , Hada Sakae , Neya Saburo
Published: July 2006

General and rigorous theory for equilibrium concentrations of uncomplexed species and 1 : 1, 1 : 2, 2 : 1, and 2 : 2 complexes of cyclodextrin (D) and surfactant has been developed and applied to evaluate the binding constants of these complexations from surface tension data of aqueous solutions of dodecyl maltoside (DM) with α-, β-, and γ-D, reported by Saeger and Muller-Fahrnow. The orders of the binding constants for 1 : 1 and 2 : 1 complexations of D and DM are α-D > β-D > γ-D. Those for 1 : 2 and 2 : 2 complexations are γ-D > β-D > α-D. These orders are explained on the basis of the goodness of fit of the dodecyl chain into the cyclodextrin cavity. Furthermore, the theory for the effects of D on the molar conductivity and the critical micelle concentration (cmc) of an ionic surfactant is modified by accounting for the change of these values with the surfactant concentration and applied to evaluate the binding constants for 1 : 1, 1 : 2, and 2 : 1 complexations of sodium dodecyl sulfate (SDS) and β-D from conductance and cmc data reported by Palepu and Reinsborough. Although there are several uncertainties in experimental data and their interpretations for the β-D-SDS system, the 1 : 1 complexation is predominant and its binding constant appears to be 5000 dm3 mol−1. Based on the present analysis, it is suggested that since a surfactant is a long and fine molecule, relative to aromatic compounds, its ternary and quaternary complexes with D’s as well as its binary complex should be taken into consideration.
Rate Constants of the Photodegradation and Photoisomerization of Polyenes Produced in Heat-Treated PVA Film
Authors: Maruyama Kazunori , Kuramoto Yasunori , Tanizaki Yoshié , Kobayashi Michio , Kuchitsu Kozo
Published: July 2006

The rate constants of two parallel reactions, photodegradation and photoisomerization of polyenes,n with n = 2–5, produced in heat-treated PVA film are estimated by an analysis of the spectral changes on monochromatic irradiation (200–250 nm). The rate constants for isomerization is found to be ten times as large as that of degradation.H=CH
The Kinetic Study of the Oxygen-Exchange Reaction of Some Alkylarsonates and Dialkylarsinates with Water
Authors: Okumura Akiko , Fushimi Midori , Hanaki Hiroko , Yamada Akiko , Gofuku Youko , Kagawa Mika , Niwa Nobuko , Yamamoto Masako , Iida Masayasu
Published: July 2006

The rates (RS) of the oxygen exchange reaction of alkylarsonates (methyl-, butyl-, hexyl-, and benzyl-) and dialkylarsinates (dimethyl- and dibutyl-) with solvent water were measured in the pH range greater than 6, and at temperatures between 30 and 0 °C. For arsonates, the rate (R) is expressed by the following rate law: R = k1[A2−] + k2[HA−] + k3[H2A] + k4[HA−]2 + k5[HA−][H2A] + k6[H2A]2, where A2−, HA−, and H2A designate R′AsO32−, R′AsO3H−, and R′AsO3H2 (R′ = alkyl), respectively. For arsinates, R = k1[R′2AsO2−] + k2[R′AsO2H] (pH > 9). The exchange rates of arsonates at 0 and 30 °C were analyzed in terms of the rate law to obtain the values of the rate constants (k1–k6). The activation parameters were obtained for the k1 paths of both arsonates and arsinates, which are the reaction between R′AsO32− or R′2AsO2− and water. It is noticeable that the values of the activation entropies of the arsonates were found to be negative, while those of the arsinate were found to be positive. It was suggested that the oxygen exchange of arsonate ions proceeds via an SN2 mechanism, while that of arsinates preceeds via SN1.
183W NMR and X-Ray Crystallographic Studies on the Peroxo Complexes of the Ti-Substituted α-Keggin Typed Tungstophosphates
Authors: Yamase Toshihiro , Ozeki Tomoji , Motomura Shigeyuki
Published: July 2006

Peroxo complexes prepared by the reaction of titanoundecatungstophosphate (PTiW11O405−) and dititanodecatungstophosphate (PTi2W10O407−) with hydrogen peroxide are characterized by means of the 183W NMR spectroscopy and the single crystal X-ray diffractometry. Electronic spectra and permanganate titration analyses indicated that one peroxo ligand attaches to the PTiW11O405− anion and two peroxo ligands attach to the PTi2W10O407− anion. 183W NMR spectra showed that the Cs symmetry of the PTiW11O405− anion and the C2 symmetry of the PTi2W10O407− anion are retained in the respective peroxo derivatives. Single crystal X-ray structures of the diisopropyl ammonium salt of PTiW11O405−, the diisopropyl ammonium salt of PTiW11O39(O2)5− and the isopropyl ammonium salt of PTi2W10O38(O2)27− indicated that the peroxo anions retain the α-Keggin structures of their parent anions. It was inferred that the peroxo ligands are substituted for the terminal oxygen atom at the TiO6 octahedra with the side-on format.
Structural and Conducting Properties of (TTF)(DMeT-DCNQI)
Authors: Mori Takehiko , Inokuchi Hiroo
Published: July 2006

The title charge-transfer complex, where TTF is tetrathiafulvalene, and DMeT-DCNQI is 2,5-bis(methylthio)-p-benzoquinone bis(N-cyanoimine), crystallizes in triclinic space group , a = 15.447 (3), b = 15.774 (3), c = 3.834 (2) Å, α = 96.96 (3), β = 97.14 (3), γ = 82.24 (2)°, V = 913 (5) Å3 and Z = 2. The donor and acceptor molecules form segregated colums. This complex shows high electrical conductivity, 400 S cm−1 at room temperature, and undergoes a metal-semiconductor transition at around 130 K.
The Fluorescence Properties of (2-Nitro-5,10,15,20- tetraphenylporphyrinato)zinc
Authors: Takahashi Kohshin , Hase Shino , Komura Teruhisa , Imanaga Hiroto , Ohno Osamu
Published: July 2006

The photophysical and redox properties of (2-substituted porphyrinato)zinc derivatives in various solvents are investigated. Zinc complexes of 2-bromo-, 2-cyano-, and 2,3-(l,4-phenylenedinitrilo)-substituted porphyrins as well as (tetraphenylporphyrinato)zinc (Zntpp(H,H)) exhibit well-resolved Q0,0 and Q0,1 fluorescence peaks, while (2-nitro-substituted porphyrinato)zincs emit a red-shifted fluorescence with a less resolved vibrational fine structure. Stokes shift of (2-nitro-5,10,15,20-tetraphenylporphyrinato)zinc (Zntpp(H,NO2)) is considerably larger than that of Zntpp(H,H), and increases with the increase in the dielectric constant of aprotic solvents. The results are ascribed to the intramolecular charge transfer from the porphyrin ring to 2-nitro group in the lowest singlet excited state of Zntpp(H,NO2).
Determination of Arsenic(III) and Arsenic(V) by Hydride Generation– Atomic Absorption Spectrometry Following a Rapid Coprecipitation Technique with Hafnium(IV) Hydroxide
Authors: Ueda Joichi , Kagaya Shigehiro
Published: July 2006

Hafnium(IV) hydroxide quantitatively coprecipitates 10–120 ng of arsenic(III) and arsenic(V) from a 100– 300 cm3 sample solution at pH 6.0–10.5. After coprecipitation, arsenic(III) can be sensitively determined by heated quartz glass cell atomic absorption spectrometry utilizing arsine generation with sodium tetrahydroborate; arsenic(V) can also be determined in the same manner as above after reducing it to arsenic(III). Interference from hafnium(IV) in the determinations of arsenic (III) and arsenic (V) can be eliminated by using perchloric acid and potassium iodide, respectively. The calibration curves are linear from 0.5–6.0 ng cm−3 for both arsenic(III) and arsenic(V). Since this method can be used to determine arsenic(III) as well as the sum of the amounts of arsenic(III) and arsenic(V), it is possible to determine arsenic(III) and arsenic(V) consecutively.
Complex Formation of Poly(acrylic acid) with Mg, Mn, and Pb Ions in Dioxane-Water Mixed Solvents
Authors: Hayashi Hiromichi , Komatsu Tsuyoshi
Published: July 2006

Equilibria between poly(acrylic acid) and Mg(II), Mn(II) and Pb(II) ions have been investigated at 25 °C by means of potentiometric and viscometric titrations in dioxane-water mixed solvents containing 0.1 mol dm−3 added salt to maintain a constant ionic strength. The stability constant for the complex formation reaction, M2+ + iA− = MAi2−i, and the equilibrium constant for the reaction, M2+ + iHA = MAi2−i + nH+ (HA denotes a carboxyl group) have been evaluated from the data of pH titration. Although the stability constants, β1 and β2, increased with dioxane content in the mixed solvent and depended on the kinds of added salts, the equilibrium constants, B1 and B2, were almost independent of both factors. The values of B1 for Mg, Mn, and Pb monocarboxylate complexes were 10−3.1, 10−2.5, and 10−1.0 and those of B2 for Mg, Mn, and Pb dicarboxylate complexes were 10−7.6, 10−5.7 and 10−2.1, respectively. From the data of viscometric titrations of poly(acrylic acid) solutions containing Pb(II) ion, it is considered that the contraction of polymer coil is caused by the intramolecular complex formation with two remote carboxylate groups in the range of low degree of neutralization (α′). As α′ increases, the complex is transformed into another form which consists of two adjacent carboxylate groups.
Triethylborane Induced Radical Reaction of Ketene Silyl Acetals with Polyhalomethanes
Authors: Miura Katsukiyo , Sugimoto Jiro , Oshima Koichiro , Utimoto Kiitiro
Published: July 2006

The treatment of ketene silyl acetal with tetrahalomethane or trihalomethane at room temperature in the presence of a catalytic amount of Et3B provides 3,3-dihaloacrylate or (E)-3-haloacrylate, respectively. On the other hand, a reaction at −23 °C mainly gives 3,3,3-trihalopropanoate or 3,3-dihalopropanoate.
Mixing State of 1-Propanol Aqueous Solutions Studied by Small-Angle X-Ray Scattering: A New Parameter Reflecting the Shape of SAXS Curve
Authors: Hayashi Hisashi , Udagawa Yasuo
Published: July 2006

Small-Angle X-ray Scattering (SAXS) of 1-propanol aqueous solutions was measured at various temperatures with a newly constructed point-focusing diffractometer. Owing to the improvement of the SAXS data, it is now possible to accurately determine the higher order coefficients in a polynomial expansion. Accordingly, a new parameter which reflects the shape of the SAXS curve (χ) is proposed. The mixing states of 1-propanol aqueous solutions are discussed in terms of χ as well as the concentration fluctuation and correlation length which are also derived from SAXS measurements. Every obtained result implies that the mixing state of the solution changes very much above and below a concentration of about 15 mol%, and that the new parameter (χ) is very effective as an indicator.
Intramolecular Radical Cyclization of Ketene Dithioacetals
Authors: Yamamoto Makoto , Furusawa Atsuko , Iwasa Seiji , Kohmoto Shigeo , Yamada Kazutoshi
Published: July 2006

A novel intramolecular ketene radical cyclization was described. Treatment of α-bromo-β-alkoxycarbonyl- and α-bromo-β-oxoketene dithioacetals with tributyltin hydride and AIBN gave lactones and cyclic ketones bearing bis(methylthio)methylene substituent at α-position in moderate yields. Tandem radical cyclization of ketene radical synthons were also carried out.
Syntheses and Structures of Novel Ruthenium(II)-Chiral Diphosphine Complexes
Authors: Kawano Hiroyuki , Ikariya Takao , Ishii Youichi , Kodama Teruyuki , Saburi Masahiko , Yoshikawa Sadao , Uchida Yasuzo , Akutagawa Susumu
Published: July 2006

Novel ruthenium complexes coordinated with various chiral diphosphines were synthesized by reactions of polynuclear [RuCl2(cycloocta-1,5-diene)]n with the respective diphosphines in the presence of triethylamine. The compositions of the complexes thus obtained were varied according to the solvent used (toluene or ethanol). The structures and dynamic properties of the complexes bearing 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (binap) in solution were elucidated by the 1H and 31P{1H} NMR measurements. The X-ray diffraction analysis of trans-RuHCl((R)-binap)2 indicated that the conformation of seven-membered chelate rings and the edge-face manner of phenyl groups were almost the same as those of corresponding rhodium complexes.
Syntheses and Magnetic Properties of Imidazolate-Bridged Binuclear Copper(II) Complexes: Effect of Bridging Mode upon Magnetic Interaction
Authors: Ohkubo Sakurako , Inoue Keiji , Tamaki Hiroko , Ohba Masaaki , Matsumoto Naohide , Okawa Hisashi , Kida Sigeo
Published: July 2006

Three imidazolate-bridged binuclear copper(II) complexes [Cu(A)Cu(Ln)]ClO4, 1 (n = 1), 2 (n = 2), and 3 (n = 3), have been prepared and characterized, where H2A = 4-(6-methyl-8-hydroxy-2,5-diazanonane-1,5,7-trienyl)imidazole, HL1 = N-salicylidene-2-(2-pyridyl)ethylamine, HL2 = N-(1-methyl-3-oxobutylidene)-2-(2-pyridyl)ethylamine, and HL3 = 3,3′-(trimethylenedinitrilo)-bis[2-butanone oximate]. The cryo-magnetic susceptibility data (4.2–300 K) of 1 and 2 were well reproduced by the Bleaney–Bowers equation based on H = −2JSCu · SCu with the J values of −46.1 and −36.6 cm−1, respectively, while the magnetic data of 3 showed no magnetic interaction. The reference complexes [Cu(Ln)(py)]ClO4 (n = 1,2; py = pyridine) have been subjected to single-crystal X-ray diffraction analysis.
Cyclic Voltammetric Behavior and Some Surface Characteristics of the Lead Electrode in Aqueous NaI Solutions
Authors: El-Halim A Mohamed Abd , Fawzy Mohamed Hossam , El Rehim Sayed Sabet Abd , Saty Abd El Kader
Published: July 2006

Cyclic voltammograms of the quiescent lead electrode were examined in NaI solutions of various concentrations ranging between 0.03 and 1.30 M (1 M = 1 mol dm−3). Neither visual PbI2 surface layer nor a typical voltammogram could be obtained unless five complete cycles were preformed in advance. This behavior was not observed for the cyclic voltammetric behavior of the lead electrode in chloride and bromide solutions and consequently could be referred to the less aggressive nature of the I− ion in comparison to the former halide ions. The data proved that the formation of a passivating layer of PbI2 is a reversible process and depends primarily upon the concentration of NaI. By controlling the voltammetric conditions, particularly the number and mode of repeated cycles, thickening of the PbI2 surface layer could be feasible. Moreover, the microstructure of the PbI2 surface layer, as revealed by scanning electron microscopy, exhibited a simple correlation to the operating conditions. The obtained results pointed to the importance of the preceding complete cycles in building up of a relatively thick layer of spongy lead. Consequently, this layer is much more available for the formation of a thick, fine grained, and more compact PbI2 surface layer by a reasonable number of only anodic spans. Investigation of the anodic surface products by X-ray diffractometry proved that the layers are formed of PbI2 in the hexagonal crystalline structure and contamination by any other species could not be detected.
Extraction and Spectrophotometric Determination of Palladium with Pyridine-2-acetaldehyde Salicyloylhydrazone
Authors: Sinha Sunetra H , Sawant Arun D
Published: July 2006

A simple and rapid method is proposed for the separation by solvent extraction and spectrophotometric determination of palladiuim(II) with pyridine-2-acetaldehyde salicyloylhydrazone (PASH). The optimum conditions were evaluated by studying critically pH, reagent concentration, and period of equilibration. The palladiuim was determined by measuring Pd(II)–PASH extracted complex in chloroform at 425 nm. The proposed method offers excellent separation of Pd(II) from rutheniuim, cobalt, nickel, copper, and rhodium. The method was applied for the analysis of palladium catalyst and platinum ores.
Diphenyl (2,3-Dihydro-2-thioxo-3-benzoxazolyl)phosphonate: A New, Reactive Condensing Agent for the Synthesis of Amides, Esters, Peptides, and β-Lactams via Condensation
Authors: Ueda Mitsuru , Mori Hideharu
Published: July 2006

Diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate (1) prepared from 2-benzoxazolethiol and diphenyl phosphorochloridate was proved to be a very useful condensing agent. A variety of amides, esters, and dipeptides were obtained in excellent yields. Furthermore, this reagent was successfully applied to the synthesis of β-lactams from β-amino acids.
Formation of Through-Ring α-Cyclodextrin Complexes with α,ω-Alkanedicarboxylate Anion.Effects of the Aliphatic Chain Length and Electrostatic Factors on the Complexation Behavior
Authors: Watanabe Midori , Nakamura Hiroshi , Matsuo Taku
Published: July 2006

α,ω-Alkanedicarboxylic acid anions with a long spacer methylene chain were observed to form dynamically and statically stable complexes with α-cyclodextrin (α-CD) at an NMR time scale in both neutral and basic media. The structures of these complexes were confirmed to be a “through-ring” type CD complex by measurements of the intermolecular NOESY and NOE difference spectra. From the thermodynamic data in basic media (pD 13), the dynamical stability of these type complexes were attributed not to the steric interaction, but to an electrostatic interaction between the dicarboxylate anion and ionized-CD.
Chiral 2-Cyanocinnamates in Conjugate Addition Asymmetric Enolate Trapping Reactions
Authors: Cativiela Carlos , Diaz-De-Villegas Maria Dolores , Galvez José Antonio
Published: July 2006

Chiral 2-cyanocinnamates react with l-selectride® to give an intermediate enolate which can be stereoselectively trapped with different halides to afford α-substituted phenylalanine precursors with excellent chemical yields and good diastereomeric excess.
Regioselective Allylations of Pyrimidine Ribonucleosides Using Pd(0) Catalyst
Authors: Kumar Vaijayanti , Gopalakrishnan Vidhya , Ganesh K Nagappa
Published: July 2006

A novel procedure for regiospecific O-allylation of pyrimidine ribonucleosides is reported by using Pd(PPh3)4–allyl ethyl carbonate reagent to synthesize 2′-O-allyluridine and 2′-O-allylcytidine. 3-N-allylation of the pyrimidine ring is prevented by protection of uridine imide function by 4-O-(2,5-dimethylphenyl) group which can be transformed to 4-oxo function of uridine or exocyclic amino function of cytidine.
Competitive Intramolecular Electron Transfer and SN2 Reactions of Radical Anions. Effects of Solvent Polarity on the Reaction Mechanism
Authors: Kimura Norio , Takamuku Setsuo
Published: July 2006

The solvent effects on the chemical reactivities of the radical anions of 1-(4-biphenylyl)-ω-chloroalkane have been investigated by using a pulse radiolysis technique. The reaction rates and reaction mechanism (intramolecular electron transfer and SN2) were found to change as a function of the polarity of the solvent used. On the basis of these results, it is discussed how their dichotomy takes place.
CO2 Laser Induced Sensitized Dissociation of Ethylene Oxide
Authors: Vatsa Rajesh Kumar , Kumar Awadhesh , Rao Kemmannu Annaji , Chowdhury Pradyot Kumar , Rama Rao Kuchimanchi Venkata Subba
Published: July 2006

Ethylene Oxide (C2H4O), when excited by energy transfer from SF6 using a pulsed CO2 laser, undergoes isomerization to CH3CHO followed by dissociation. The intermediate isomerized product, acetaldehyde, is formed with excess internal erergy sufficient to decompose into CH3 and CHO radicals. CH3 radicals could be trapped by their reaction with chlorine, forming CH3Cl as a stable product. Also, the intermediate acetaldehyde could be partially stabilized in the presence of argon. An average excitation energy of C2H4O molecule was found to be 65 kcal mol−1. Average number of photons absorbed per SF6 molecule, , was calculated to be 13 from the direct measurement of absorbed energy. The product distribution indicates that radical chain mechanism does not play a significant role in the present laser induced reaction.
Tautomerization and Dissociation Equilibria of β-Diketones in Microemulsions
Authors: Watarai Hitoshi , Takano Mikako , Suzuki Nobuo
Published: July 2006

The keto–enol tautomerization and dissociation equilibria of benzoylacetone, benzoyltrifluoroacetone, and 2-naphthoyltrifluoroacetone were studied in anionic, cationic, and nonionic microemulsions by means of UV spectrophotometry. The enol fraction in the microemulsions, which increased with an increase of the volume fraction of the organic components, was explained by the distribution model of the β-diketones between the pseudo-phases. The apparent dissociation constants in the cationic microemulsions were larger than those in the anionic or nonionic microemulsions. This result is discussed based on the distribution of the enolate form into the interphase, which was significantly affected by the surface charge of the microemulsions.
Rotational Distribution of CO(b3Σ+) Produced in Energy Transfer Reaction from Ar(3P2) to CO
Authors: Tsuji Masaharu , Yamaguchi Kazuo , Kikukawa Mitsuo , Kouno Hiroyuki , Funatsu Tsuyoshi , Nishimura Yukio
Published: July 2006

The rotational energy disposal of CO(b3Σ+) in the Ar(3P2) + CO reactions has been measured by observing CO(b3Σ+–a3Πr) emission in an Ar flowing afterglow. The initial rotational distribution of CO(b : ν′ = 0,1) was expressed by a single Boltzmann temperature of 7000 ± 700 K. The fraction of available energy deposited into rotational mode of CO(b), , was estimated to be 32 ± 2%.
Dielectric Behavior of Aqueous Binary Mixtures of Hydrophobic Solutes
Authors: Prabhu Peesapati Venkata Seshadri Sekhar , Ramanamurti Medepalli Venkata
Published: July 2006

Dielectoric constant data for aqueous binary mixtures of ethylene glycol (EG), 2-methoxyethanol (ME), and 1,2-dimethoxyethane (DME) at different mole fractions and at various temperatures are reported. A decrease in dielectric constant values has been observed with the increase in solvent content of the mixture as well as the temperature in case of all the three systems. The variations in Kirkwood’s correlation factor (gK) with respect to the solvent composition in the three types of mixtures have been attributed to the short-range dipolar interactions which lead to structural changes in respective solvent mixtures.
Paper Chromatographic and 1H NMR Study of Ion Pair Interactions between N-Dodecanoylhistidine Methyl Ester and Dodecyl Dihydrogenphosphate in Chloroform
Authors: Verma Jyoti , Sahal Dinkar
Published: July 2006

A mixture of N-dodecanoylhistidine methyl ester (DHOMe) and dodecyl dihydrogenphosphate (DDP) gave a chromatographically distinct complex in chloroform, where the imidazole staining was markedly enhanced and the phosphate staining showed a characteristic delayed appearance. The 1H NMR chemical shift of 8.53 ppm (imidazole C–2H) observed for a 1 : 1 mixture of the two amphiphiles was downfield shifted by nearly 1.0 ppm vis-à-vis DHOMe alone. The data suggest that the complex between DHOMe and DDP in chloroform is stabilized by hydrogen bonding and ion-pair interactions.
Structures of Two Geometrical Isomers of Dioxo[(S)-N-salicylidene-3-aminopyrrolidine]vanadium(V)
Authors: Nakajima Kiyohiko , Tokida Nobuko , Kojima Masaaki , Fujita Junnosuke
Published: July 2006

The title complex was prepared and the crystal structure was determined by the X-ray method. Two geometrical isomers are involved in a unit cell. For each isomer, the coordination polyhedron is a distorted square pyramid, and the two isomers differ from each other with respect to the mutual disposition of the basal chelate ligand and the apical V=O group.
Catalytic Asymmetric Synthesis of Optically Active Secondary Alcohols Deuterated on the Secondary Carbon by the Enantioselective Alkylation of Aldehydes
Authors: Soai Kenso , Hirose Yuji , Sakata Shuichi
Published: July 2006

Optically active secondary alcohols deuterated on the secondary carbon were obtained in high enantiomeric excesses from the enantioselective addition of dialkylzincs to aldehyde–formyl-d’s using chiral catalysts.
Synthesis of [l-α-Aminomyristic Acid3,3′]gramicidin S and Its Interaction with Phospholipid Bilayer
Authors: Mihara Hisakazu , Nishino Norikazu , Ogawa H Iyehara , Izumiya Nobuo , Fujimoto Tsutomu
Published: July 2006

A lipophilized gramicidin S (GS) analog was synthesized by introducing l-α-aminomyristic acid (Amy) residues instead of l-leucine residues by the conventional solution method. Influences of lipophilization of GS on interaction with phospholipid liposomes were examined by the peptide-induced dye-leakage assays using carboxyfluorescein (CF)-entrapped liposomes of dipalmitoyl-Dl-α-phosphatidylcholine (DPPC). The [Amy3,3′]GS (Amy-GS) had the enhanced ability of CF-leakage below the phase-transition temperature of DPPC liposomes as compared with GS, while it showed weaker leakage ability at higher temperature. Conformation of Amy-GS in solution and in the presence of liposomes was similar to that of GS, which was elucidated by CD and 1H NMR measurements. The Amy residue can be utilized to enhance the affinity of a peptide to membrane environment without changing conformation of an original peptide.
Catalytic Properties of Lanthanide Metals on Silica
Authors: Imamura Hayao , Konishi Tomohiro , Tokunaga Yu-ichi , Sakata Yoshihisa , Tsuchiya Susumu
Published: July 2006

Silica (SiO2) powders reacted readily with Eu and Yb which were dissolved in liquid ammonia, resulting in the formation of active lanthanide/SiO2 catalysts (Eu/SiO2 and Yb/SiO2). The reactions of dissolved lanthanide metals in liquid ammonia with SiO2 were characterized by FT-IR studies and various catalytic reactions. The catalytic behavior varied markedly with varied levels of lanthanide loading. At low loadings ( < ca. 15 wt%), the dissolved lanthanide selectively reacted with the hydroxyl groups on SiO2 to form ≡SiO–MNH2 species (M = Eu or Yb). The thermal treatment above 573 K led to the decomposition of this species to the inactive nitride MN. The catalyst with low loadings exhibited very high activity for the disproportionation of cyclohexadiene at room temperature. At high loadings ( > ca. 15 wt%), after the first portion of added lanthanide was consumed for the reaction with surface hydroxyl groups, subsequent lanthanide seems to deposit on SiO2 in an active metallic form. The catalytic properties were very similar to those reported for lanthanide metal particles prepared by the metal vapor technique. The catalyst with high loadings discriminated between internal and terminal C–C triple bonds for the hydrogenation of alkyne; thus, 2-butyne was readily converted to cis-2-butene, whereas 1-butyne, propyne, and acetylene were not hydrogenated at all.
Crystal Structures of Mono- and Di-nuclear Nickel(II) Complexes Derived from the Substitution Reaction of [Ni(Me2[14]dienatoN4)]I and Each of Benzoyl Chloride and Isophthaloyl Dichloride
Authors: Matsumoto Naohide , Koikawa Masayuki , Baba Norihisa , Okawa Hisashi
Published: July 2006

The reactions of (5,7-dimethyl-1,4,8,11-tetraazacyclotetradeca-4,6-dienato)nickel(II) iodide with benzoyl chloride and isophthaloyl dichloride gave mononuclear 1 and dinuclear 2 nickel(II) complexes, respectively. Complex 1 crystallized in space group P21/a with Z = 4, a = 23.704(10), b = 7.726(3), c = 11.581(4) Å, β = 104.16(3)°, V = 2056.5(1.4) Å3. The benzoyl group is positioned at the 6 position of the macrocycle and tilted to the NiN4 plane by 67.9° due to the steric hindrance from two methyl groups. Complex 2 crystallized in space group with Z = 2, a = 12.124(3), b = 16.484(4), c = 10.243(4) Å, α = 94.84(3), β = 111.04(3), γ = 80.69(2)°, V = 1884.6(1.1) Å3. The metal ions are 12.777(6) Å apart, and the two coordination planes are nearly co-planar, the dihedral angle between them being 164.4°.
Solvent Extraction of Anionic Chelate Complexes of Lanthanum(III), Europium(III), Lutetium(III), Scandium(III), and Indium(III) with 2-Thenoyltrifluoroacetone as Ion-Pairs with Tetrabutylammonium Ions
Authors: Noro Junji , Sekine Tatsuya
Published: July 2006

The solvent extraction of lanthanum(III), europium(III), lutetium(III), scandium(III), and indium(III) in 0.1 mol dm−3 sodium nitrate solutions with 2-thenoyltrifluoroacetone (Htta) in the absence and presence of tetrabutylammonium ions (tba+) into carbon tetrachloride was measured. The extraction of lanthanum(III), europium(III), and lutetium(III) was greatly enhanced by the addition of tba+; this could be explained in terms of the extraction of a ternary complex, M(tta)4−tba+. However, the extractions of scandium(III) and indium(III) were nearly the same when tba+ was added. The data were treated on the basis of the formation equilibrium of the ternary complex from the neutral chelate, M(tta)3, with the extracted ion-pairs of the reagents, tta−tba+, in the organic phase. It was concluded that the degree of association of M(tta)3 with the ion-pair, tta−tba+, is greater in the order La(tta)3 ≈ Eu(tta)3 > Lu(tta)3, or that the stability of the ternary complex in the organic phase is higher in the order La(tta)4−tba+ ≈ Eu(tta)4−tba+ > Lu(tta)4−tba+. This is similar to those of adduct metal chelates of Htta with tributylphosphate (TBP) in synergistic extraction systems.
Enzymatic Kinetic Resolution of [4](1,2)Ferrocenophane Derivatives
Authors: Izumi Taeko , Tamura Futoshi , Sasaki Kenryo
Published: July 2006

The enol acetate of (±)-[4](1,2)ferrocenophan-1-one was enantioselectively hydrolyzed by using lipase PS to afford (+)-(R)-[4](1,2)ferrocenophan-1-one and (+)-(S)-1-acetoxy[4](1,2)ferrocenophan-1-ene. By using lipase PS or lipozyme, (±)-1-acetoxy[4](1,2)ferrocenophane was resolved into the (+)-(1R)-alcohol and the (−)-(1S)-acetate. The lipase-mediated transesterification and esterification of (±)-1-hydroxy[4](1,2)ferrocenophane led to the formation of the (+)-(1R)-ester and the (−)-(1S)-alcohol.
1-Haloalkyl Aryl Sulfoxides as Useful Agents in Synthesis of α-Halo Ketones: A New Synthesis of α-Halo Ketones, α-Halo α,β-Unsaturated Ketones, and α-Halo Cross Dienones from Aldehydes
Authors: Satoh Tsuyoshi , Itoh Norifumi , Onda Ken-ichi , Kitoh Yasushi , Yamakawa Koji
Published: July 2006

α-Halo α-sulfinyl ketones were synthesized in two steps from 1-haloalkyl aryl sulfoxides and aldehydes in high yields. Desulfinylation of the α-halo α-sulfinyl ketones was performed with ethylmagnesium bromide in ether at low temperature to afford α-halo ketones via magnesium enolates in high yields. The magnesium enolate intermediates were trapped with various electrophiles such as deuterium oxide, ethyl chloroformate, and chlorotrimethylsilane. Trapping of the magnesium enolate intermediate with carbonyl compounds afforded a new type of the directed aldol reaction. Desulfinylation of the sulfinyl group of the α-halo α-sulfinyl ketones under thermal conditions gave α-halo α,β-unsaturated ketones or α-halo cross dienones.
A Formation of a Fusarubin Carbon Skeleton
Authors: Tanoue Yasuhiro , Terada Akira
Published: July 2006

A compound having a fusarubin carbon skeleton, N,N-diethyl-3-(2-hydroxypropyl)-1,4,5,6,8-pentamethoxy-2-naphthamide, was prepared from 1,4,5,6,8-pentamethoxy-2-naphthalenemethanol in 5 steps via N,N-diethyl-1,4,5,6,8-pentamethoxy-7-trimethylsilyl-2-naphthamide.
Electrochemically Oxidative Polymerization of 1,2,3,4-Tetrahydronaphthalene
Authors: Akiyama Fuminori
Published: July 2006

Electrochemical oxidation of 1,2,3,4-tetrahydronaphthalene (1) at higher anode potential than 3.0 V and high concentration of 1 gave a polymer of 1. The polymer deposited on an anode was slightly soluble in organic solvents and the polymer separated from the solution had number average molecular weight up to 1500.
Photochemistry of 1,2 : 4,5-Benzenebis(dicarboximide). Insertion of Alkenes into the C-N Bond of N,N′-Dihexyl-1,2 : 4,5-benzenebis(dicarboximide)
Authors: Kubo Yasuo , Tanabe Seiichi
Published: July 2006

In the photolyses of acetonitrile solutions of N,N′-dihexyl-1,2 : 4,5-benzenebis(dicarboximide) (1) and alkenes, insertion of the double bond in the alkenes into the C–N bond of the imide function of 1 was observed. The insertion reaction proceeded along with a retention of the stereochemistry of the alkenes in reactions with trans- and cis-2-butene.
Random Packing of Ions in the Ionic Glass xKNO3·(100−x)Sr(NO3)2 (x = 22–60) and the γ-Ray Induced Cleavage of K–ONO2 Bonds
Authors: Nishida Tetsuaki , Ohara Masakazu , Takashima Yoshimasa
Published: July 2006

The IR peak positions of the ν3 (1386 cm−1), ν2 (814 cm−1), and ν4 (737 cm−1) modes of NO3− are constant in nitrate glasses. This is also the case for the Sr–ONO2 (1439 cm−1) and K–ONO2 (1270 cm−1) bonds. The latter peak is observed only in glasses in which the degeneracy is removed due to the lowered symmetry (D3h → C2ν).
Shape-Selectivity Effect of Highly Reduced Cobalt-Exchanged Zeolite in the Fischer-Tropsch Reaction
Authors: Lee Young Seub , Koh Dong Jun , Chung Jong Shik , Kim Young Gul
Published: July 2006

Cobalt-exchanged zeolites, when reduced by sodium injection followed by treatment in dihydrogen at 450 °C, showed an enhanced production of long chain and linear form of hydrocarbons with a bimodally distributed non Schultz-Flory distribution. Long chain linear hydrocarbons of C12–C20 were believed to be produced on cobalt clusters located inside zeolite cage.
Vapor Phase Carbonylation of Organic Halo Compounds
Authors: Yasuda Kensei , Shinoda Kiyonori
Published: July 2006

RCH2X, s-C4H9X, and C6H5X were methoxycarbonylated with carbon monoxide and methanol into methyl carboxylates in the presence of rhodium trichloride/potassium iodide supported on activated charcoal. The reactivity decreased in the order: X = I > Br > Cl.
Synthesis and Photochromism of Dibenzylviologen Coupled with 5,10,15,20-Tetraphenylporphyrin or Its Metal Complex via a Carbonyloxy Spacer
Authors: Kamogawa Hiroyoshi , Koga Kazuhi
Published: July 2006

1,1′-Dibenzyl-4,4′-bipyridinium (viologen) coupled with 5,10,15,20-tetraphenylporphyrin or its metal complex via a carbonyloxy spacer was prepared by modification of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin. The viologens in polar aprotic media brought about increases in the visible absorption characateristic of, but different in stability from, those of the conventional viologen radical cations upon irradiation with visible light (photochromism).
Synthesis of Two Types of Intercalation Compounds of K4Nb6O17 with Tris(2,2′-bipyridyl) Metal Complex Ions
Authors: Nakato Teruyuki , Sakamoto Daisuke , Kuroda Kazuyuki , Kato Chuzo
Published: July 2006

K4Nb6O17 is a layered material with two different types of interlayer spaces, interlayer I and interlayer II. It was found that two types of intercalation compounds of K4Nb6O17 with alkylammonium ions were formed, one in which alkylammonium ions were present in interlayer I only, and the other in which they were present in both the interlayers. Intercalation of [M(bpy)3]2+ (M: Fe, Ru, Ni) into K4Nb6O17 was carried out using these two types of alkylammonium-intercalated K4Nb6O17 as the intermediates. Ion exchange reactions of the interlayer alkylammonium ions for the complex ions were conducted, and the formation of two types of products, one in which [M(bpy)3]2+ ions were present in interlayer I only and the other in which they were present in both the interlayers, was confirmed from powder X-ray diffraction patterns and the compositions of the products.
Photosensitized Oxidation of Ethanol on Alkoxy-Derived TiO2 Powders
Authors: Kato Kazumi
Published: July 2006

In order to consider the factors affecting the photocatalytic properties of TiO2, TiO2 powders with controlled characteristics such as the crystalline phase, the crystallite size, and the specific surface area were prepared by hydrolyzing Ti(Oi-C3H7)4. The photocatalytic property of the photo-oxidation of ethanol on the powder depended on the crystallite size and the microstructure. Ethanol was oxidized completely in the suspensions of the powders after illumination for 2 h while being bubbling with oxygen. The crystallite sizes of the powders were in the range of 20–30 nm. The microstructure of the powders consisted of the aggregation of fine and individual particles.
Synthesis and Characterization of Doubly-Strapped Porphyrins
Authors: Nagata Toshi
Published: July 2006

Synthesis of a “doubly-strapped” porphyrin is described, which has two –O(CH2)10O– straps on both sides of the porphyrin ring. This porphyrin did not form the zinc complex when treated with zinc acetate, even under forcing conditions. Such inertness toward zinc insertion can be attributed to the steric hindrance of the –O(CH2)10O– straps. Oligoporphyrins with one strapped ring were also synthesized. Reaction of these porphyrins with zinc acetate resulted in insertion of zinc into all non-strapped rings, while the strapped ring remained unchanged. These doubly-strapped porphyrins will be useful in constructing oligoporphyrins as photosynthetic model compounds, in which photochemical and electrochemical properties are controlled by selective metal insertion.
A Convenient Synthetic Method of 2-Cyano-6-methoxybenzothiazole, –A Key Intermediate for the Synthesis of Firefly Luciferin
Authors: Toya Yoshiaki , Takagi Masaharu , Nakata Hisao , Suzuki Nobutaka , Isobe Minoru , Goto Toshio
Published: July 2006

The title compound was prepared in one step from commercially available 2-amino-6-methoxybenzothiazole by using the Sandmeyer cyanation reaction. The result enabled us to synthesize firefly luciferin effectively from this amino compound through three steps in 36% overall yield.
Numerical Formulation of Pigment Release from Magnetically Anisotropic Gel Beads with Respect to the Magnetic Moment in an Alternating Magnetic Field
Authors: Sakai Yasuzo , Kuwahata Mitsuyoshi , Takahashi Fujio
Published: July 2006

Quantitative measurements were carried out regarding the change of pigment release (ΔCP/CP) from magnetically anisotropic gel beads (MA gel beads) prepared in the presence and absence of an alternating magnetic field in various conditions. The rate of pigment release from the MA gel beads was found to be proportional to the magnetic moment of the beads. The magnetic moment of the MA gel beads was proportional to the concentration of ferrite (CF) and the strength of a static magnetic field (HS) used for the preparation of the MA gel beads. In this connection, M1/V was proportional to CF·HS, where M1 and V are the magnetic moment and the volume of a grain of the MA gel beads, respectively. As a result, we derived an experimental equation for the rate of pigment release as a functions of M1, V and the strength of an alternating magnetic field (HA) as ΔCP/CP = kM1HAV−0.5, where k is constant.