bluuebunny/crossref_metadata_2025 huggingface dataset:
Esterification, Etherification, and Aldol Condensation Using Cathodically-Generated Organic Olate Anions
Authors: Fuchigami Toshio , Awata Takeshi , Nonaka Tsutomu , Baizer Manuel M
Published: July 2006

Cathodic methods for the esterification of carboxylic acids and the etherification of phenol and benzenethiol under mild conditions were developed. The esterification was successfully carried out at room temperature by the reaction of alkylating reagents with cathodically-generated quaternary ammonium carboxylates. The etherification was similarly achieved using electrogenerated quaternary ammonium phenolate and halonitrobenzenes. A hindered phenolate anion cathodically-generated from 2,6-di-t-butyl-p-cresol remarkably promoted aldol condensation of aromatic ketones and aldehydes, and allowed subsequent Michael reaction to provide efficiently symmetrical 1,5-diketones.
The Oxidation of Methylbenzenes and Naphthalenes to Quinones with H2O2 in the Presence of Palladium Catalyst
Authors: Yamaguchi Satoru , Inoue Masami , Enomoto Saburo
Published: July 2006

Methylbenzenes and naphthalenes were oxidized to quinones with aqueous(60%) H2O2 in acetic acid in the presence of a 0.24 wt% Pd(II)-sulfonated polystyrene type resin. The selectivities to quinones were higher in naphthalenes than in methylbenzenes. Among the naphthalenes used, 2-methylnaphthalene, 2,3-dimethylnaphthalene, and 2,6-dimethylnaphthalene gave 1,4-quinones in good yields(50–64%). The increase in the reaction temperature increased the selectivity to quinones from 40% at 20 °C to 70% at 70 °C.
Effect of Pore-Size Distribution on the Catalytic Performance for Coal Liquefaction. II. Carbonaceous and Metallic Deposition on the Catalyst
Authors: Shimada Hiromichi , Kurita Minoru , Sato Toshio , Yoshimura Yuji , Kobayashi Yoshinori , Nishijima Akio
Published: July 2006

The behavior of carbonaceous and metallic depositions on catalysts during hydroliquefaction of coal was investigated by using several kinds of catalyst supports with different pore-size distribution values in order to obtain the fundamental data for designing long-life catalysts. Higher concentration of carbonaceous deposition was observed on large-pore and bimodal catalysts than was observed on the comparative small pore and unimodal catalysts, respectively. However, the carbonaceous deposit was distributed more evenly inside large pores than it was inside small pores. The micropores of the bimodal catalysts were more effectively used than were those of the unimodal catalysts. Thus, the unimodal catalysts with small pores suffered more severe pore-mouth poisoning than the bimodal or the large-pore catalysts. The penetration behavior of the metallic components was found to be different for each metal. Discrete minerals such as clay could not penetrate into the catalyst pores and were deposited on the external surface of the catalyst particle. While, the metallic components coordinated with organic compounds such as phenolates or chelates deposited inside the macro- and mesopores. Easy access of the large asphaltenic molecules to the active sites resulted in high coal-liquefaction activity for the catalyst. This was accompanied by large amounts of both carbonaceous and metallic depositions. It is concluded that large-pore or bimodal pore structure is required for both high liquefaction activity and suppression of pore-mouth poisoning.
The Magnetic Properties of the Copper(II) Compounds with 3- and 4-Piperidinecarboxylic Acids
Authors: Emori Shuji , Morishita Nobuhide , Muto Yoneichiro
Published: July 2006

Compounds of formula [CuX2(C5H11NCOO)2]·3H2O (X=NO3, Cl, Br), [Cu(NO3)2(C5H11NCOO)2]·2(NH2)2CO, and Cu[(CH3)2CHCOO]2·(NH2)2 CO have been prepared. The correlation of their magnetic properties with the pKa values of their parent carboxylic acids is discussed.
Tautomeric Equilibrium of Salicylidene Schiff Base. UV-Visible Absorption and Raman Spectroscopic Studies
Authors: Lee Ho-hi , Kitagawa Teizo
Published: July 2006

The solvent effect and temperature dependence on the Raman and absorption spectra demonstrated the existence of a tautomeric equilibrium for the title compound between the enol form and the protonated Schiff base form in methanol; the latter form is more stable by ca. 850 cal mol−1(1 cal=4.184 J) than the former. Characteristic Raman bands for the two tautomers have been identified.
Selective Allylation of Sodium Naphtholate
Authors: Yamada Shigetoshi , Takeshita Toru , Tanaka Juntaro
Published: July 2006

The reaction of 1- or 2-naphthol with allylic halides (1-chloro-3-methyl-2-butene, 1-chloro-3,7-dimethyl-2,6-octadiene, trans-1-chloro-2-butene and trans-1-chloro-2-hexene) in the presence of metallic sodium gave naphthols having the corresponding allylic group selectively.
NAD(P)+–NAD(P)H Models. 59. 1,2- Versus 1,4-Reduction of β,γ-Unsaturated α-Keto Ester
Authors: Ohno Atsuyoshi , Yasuma Tsuneo , Nakamura Kaoru , Oka Shinzaburo
Published: July 2006

Depending on the reactivity of the reducing agent, β,γ-unsaturated α-keto ester is reduced into either β,γ-unsaturated α-hydroxy ester or saturated α-keto ester as the result of 1,2- or 1,4-reduction.
Preparation of Some 1,3-Selenazin-4-ones
Authors: Yokoyama Masataka , Kumata Katsushi , Hatanaka Hidekatsu , Shiraishi Tadashi
Published: July 2006

2-Cyano-3-hydroseleno-3-(methylthio)acrylamide reacts with carbonyl compounds in the presence of sulfuric acid and aroyl chlorides in the presence of pyridine to give the corresponding 2,3-dihydro-4H-1,3-selenazin-4-ones and 4H-1,3-selenazin-4-ones in moderate yields, respectively.
Photoreaction of N-Alkylamides Containing Iron(III) Chloride by Monochromatic Light
Authors: Yokoyama Yasushi , Suzuki Takahiro , Kurita Yukio
Published: July 2006

The photolysis of N-alkylamides containing FeCl3 using monochromatic light corresponding to the absorption maxima were examined by ESR. Irradiation by 313-nm light resulted mainly in a hydrogen abstraction from the aliphatic carbon adjacent to either CO or NH, whereas 366-nm light produced an acyl radical in larger amounts.
Structure Model for Liquid Neopentane
Authors: Nishikawa Keiko
Published: July 2006

Structure simulation studies for liquid neopentane have been carried out by the use of real space expansion and reciprocal space expansion based on the local lattice structure model. A body centered cubic (bcc) model has reproduced Narten’s experimental data very well.
Mössbauer Spectroscopic Study on the Mixed-Valence States of 1′,1'″-Bis(o-methylbenzyl)-, 1′,1'″-Bis(m-methylbenzyl)-, and 1′,1'″-Bis(p-methylbenzyl)biferrocenium Triiodide
Authors: Nakashima Satoru , Katada Motomi , Motoyama Izumi , Sano Hirotoshi
Published: July 2006

1′,1'″-Bis(o-methylbenzyl)-, 1′,1'″-bis(m-methylbenzyl)-, and 1′,1'″-bis(p-methylbenzyl)biferrocene were synthesized and Mössbauer spectroscopic measurements of their monocation salts were carried out at various temperatures in order to study the effect of the substituents on the mixed-valence states.
Study of Packing State in Lipid Bilayers with the Aid of Ultraviolet Spectroscopy
Authors: Inoue Yoshio , Seiya Yuji , Sakurai Minoru , Chûjô Riichiro
Published: July 2006

The packing states of lipid bilayers of three phosphocholines were investigated based on the density dependent UV shifts of probes incorporated into bilayers. As UV probes, two retinal Schiff bases were used. It was confirmed that the packing state of the fatty acyl chain region is well probed by UV spectroscopy.
Cubic Relation between Thermodynamic Functions and Natural Variables for Chemical Thermodynamic Systems
Authors: Isihara Makoto
Published: July 2006

The relation between thermodynamic functions and natural variables for chemical thermodynamic systems is represented in terms of the geometry of a cube. Besides being helpful in understanding the abstractive nature of thermodynamic relation, this leads to a useful mnemonic as well.
A Consideration on the Mechanism of the Wacker Reaction from the Viewpoint of the Trans Influence of Ligands (OH−>Cl−>H2O)
Authors: Shinoda Sumio , Koie Yasuyuki , Saito Yasukazu
Published: July 2006

The trans influence of three ligands (OH−, Cl−, and H2O) was compared for the first time according to the same experimental standard (1J(PtPtrans)). Based on the extremely high trans influence of the OH− ligand, a mechanism was proposed for the palladium(II) oxidation of ethylene, which includes the rate-determining external attack of H2O on a possible intermediate, trans-[PdCl2(OH)(C2H4)]−.
Crystal and Molecular Structure of a Binuclear Copper(II) Complex with 1,2,3,4-Tetrakis(salicylideneamino)-2,3-dimethylbutane
Authors: Mikuriya Masahiro , Izumitani Tatsuo , Okawa Hisashi , Kida Sigeo
Published: July 2006

The crystal structure of a binuclear copper(II) complex with 1,2,3,4-tetrakis(salicylideneamino)-2,3-dimethylbutane (abbreviated as H4sata), Cu2(sata), was determined by the single-crystal X-ray diffraction method. The complex molecule has two coordination units formed by a planar 6-5-6 fused chelate ring and takes a nonstacked form.
The Absolute Configuration of Isoprelaurefucin
Authors: Suzuki Minoru , Kurata Kazuya , Suzuki Teruaki , Kurosawa Etsuro
Published: July 2006

(3Z)-Isoprelaurefucin has been isolated as a major metabolite from the red alga Laurencia nipponica Yamada, and its structure was confirmed by chemical correlation with isoprelaurefucin. Furthermore, the absolute configuration of isoprelaurefucin was established on the basis of chemical evidence.
Studies on Special Type Surfactants. XVI. Preparation of Telomer-Type Surfactants Containing 4-Vinylpyridine and Oxidative Polymerization of 2,6-Xylenol Using Their Copper Complexes
Authors: Koide Yoshifumi , Eda Yasuyuki , Yamada Kimiho
Published: July 2006

The polymerization of 2,6-xylenol (XOH) was catalyzed by using a copper complex of a telomer-type surfactant containing 4-vinylpyridine, 1-benzyl-4-vinylpyridinium chloride, and methyl acrylate or styrene (L-VP-Q, L-VP-Q-MA, L-VP-St, and L-VP-Q-St). A copper complex of L2.5VP3.9Q2.2MA catalyzed an emulsion polymerization of XOH more than that of L-VP-Q, 4-vinylpyridine polymer (VP-Q), or pyridine. Furthermore, the oxidative polymerization of XOH in several organic solvents was more effective than emulsion polymerization. The copper complexes formed reversed-micelles in water (3–10 vol%)-DMSO, and the catalytic actions were in the following order: L-VP-Q>VP-Q>pyridine. The acceleration by the L-VP-Q complex was considered to be due to the adsorption of XOH on reversed micelles.
Solubilities and Free Energies of Transfer for Lanthanoid Iodates in Dimethyl Sulfoxide–Water Mixtures
Authors: Miyamoto Hiroshi , Iijima Hiroko , Sugawara Masako
Published: July 2006

The solubilities of lanthanoid iodates in dimethyl sulfoxide (DMSO)–water mixtures at 25 °C were measured. Thirteen lanthanoid iodate dihydrates Ln(IO3)3·2H2O (Ln=Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) were used. From the measured solubilities, the Gibbs free energies of the transfer of the iodates from water into aqueous DMSO solutions were calculated. The tetrad effect behavior reported by Peppard et al. was observed in both the variation with the lanthanoid atomic number of the solubility data and that with the atomic number of the free energies of transfer. The tetrad effect behavior seems to depend on a change in the solvation of the lanthanoid ions in variation with the crystal radii of the trivalent lanthanoid ions. In each system the logarithm of the solubility of the iodates decreases almost linearly with the reciprocal of the dielectric constant of the mixtures, as is expected from the Born equation or its modification when dealing with mixtures with narrow dielectric constant, ranging between 78.5 and 78.0.
o-Quinodimethane Generation from α,α′-Dihalo-o-xylenes by Use of Sodium Benzenetellurolate
Authors: Kambe Nobuaki , Tsukamoto Takashi , Miyoshi Noritaka , Murai Shinji , Sonoda Noboru
Published: July 2006

Treatment of α,α′-dihalo-o-xylenes with sodium benzenetellurolate gave o-quinodimethane which readily reacted with dienophiles leading to Diels–Alder adducts. The best yields were obtained when the reaction was carried out in refluxing ethanol using two molar equivalents of the benzenetellurolate to α,α′-dihalo-o-xylenes. This reaction competes with substitution of the halogen atoms with the benzenetellurolate anion to afford α,α′-bis(phenyltelluro)-o-xylene, which did not give o-quinodimethane under identical conditions. It is likely that the reaction proceeds through nucleophilic attack of benzenetellurolate anion at the tellurium atom of α-halo-α′-phenyltelluro-o-xylene which is formed in situ by the substitution of one of the halogen atoms of the starting α,α′-dihalo-o-xylene with the benzenetellurolate anion. When sodium benzeneselenolate was employed, no evidence of o-quinodimethane formation was observed under similar conditions.
Magnetic Field Effects on the Primary Photoprocess of Anthrone in Micellar Solution by Laser Flash Photolysis and Two-Step Laser Excitation Fluorescence
Authors: Tanimoto Yoshifumi , Shimada Etsuko , Itoh Michiya
Published: July 2006

The magnetic field effects on hydrogen abstraction reaction of anthrone have been studied in micellar solution by laser flash photolysis and two-step laser excitation (TSLE) fluorescence. The decaytime of the anthrone ketyl radical determined by laser flash photolysis increases from 370 ns at zero field to 890 ns at 80 mT. The results are in accordance with the magnetic field effects on the risetime of the cage product by the TSLE fluorescence. All of the results are discussed in terms of the radical pair model.
A Molecular Orbital Study of Conformational Behavior of 9,9′-Bifluorenylidene
Authors: Kikuchi Osamu , Matsushita Ken-ichi , Morihashi Kenji , Nakayama Mitsunobu
Published: July 2006

The conformation of 9,9′-bifluorenylidene and the E→Z isomerization of its derivatives were examined by a two-configuration SCF calculation with the MINDO/3 approximation. The twisted conformation was calculated to be more stable than the folded one. The E–Z isomerization occurs between two twisted conformers and the 90°-twisted structure is the transition state. The structural dependence of the rotational barrier of the isomerization is discussed.
Substituent Effects in the Acid-Catalyzed Hydrolysis of Cyclic Acetals of Benzophenones
Authors: Ueno Shinya , Oshima Takumi , Nagai Toshikazu
Published: July 2006

Eight 2,2-diaryl-1,3-dioxanes were prepared and the kinetic substituent effects regarding acidcatalyzed hydrolysis were studied in 80% dioxane–water(v/v) at 30 °C. The logk were well correlated with the Yukawa-Tsuno equation; logk⁄k0=−2.92(σ0+0.385Δ\barσR+)(r=0.999).
Spectrophotometric Determination of Micro Amounts of Pentathionate via Permanganate Reaction
Authors: Miura Yasuyuki , Koh Tomozo
Published: July 2006

A method has been developed for the determination of micro amounts of pentathionate. It is based on the reaction of pentathionate with a given amount of permanganate in a dilute sulfuric acid medium and on the spectrophotometric measurement of iodine as triiodide, which is formed by the oxidation of iodide with an excess of permanganate. The analytical conditions were established by varying the temperature, reaction time, and amounts of sulfuric acid and permanganate. The present method can be successfully applied to a determination of pentathionate in the range 2×10−7 to 1.4×10−5 mol dm−3 (0.5–35.9 μg S5O62− in 10 cm3) and gives a higher sensitivity than any previous method without solvent extraction. In eleven determinations for 10 cm3 sample solutions containing 0.080 μmol of pentathionate, the present method gave a mean value of 0.0 with a standard deviation of 0.0006 μmol and a relative standard deviation of 0.75%.
A Novel Rearrangement of Protonated 2-Bromo-5-methylthiophene
Authors: Yokoyama Yukihiro , Yamashita Yukihide , Takahashi Kensuke , Sone Tyo
Published: July 2006

A novel rearrangement of protonated 2-bromo-5-methylthiophene was observed in HSO3F by means of 1H NMR spectroscopy.
17O NMR Studies on a Series of Manganese Carbonyl Derivatives with Sn–Mn Bond(s)
Authors: Onaka Satoru , Sugawara Tadashi , Kawada Yuzo , Yokoyama Yukihiro , Iwamura Hiizu
Published: July 2006

17O NMR spectra were measured for a series of manganese carbonyl derivatives, (CH3)xCl3−xSn–Mn(CO)5−yLy and (CH3)3−xSn[Mn(CO)5−yLy]x+1(L=P(OPh)3). 17O chemical shifts were correlated with carbonyl stretching frequencies, 119Sn-Mössbauer isomer shifts, and 55Mn NMR chemical shifts. From these correlations, 17O chemical shifts were interpreted in terms of σ- and π-electron acceptance of the tin moieties. It was also clarified that 17O NMR spectroscopy is a direct method to study electronic nature around the oxygen atoms in metal cluster compounds such as Me2Sn[Mn(CO)5]2 and MeSn[Mn(CO)5]3. 55Mn NMR spectra were also measured for some of these compounds to corroborate the 17O NMR results.
Photoinduced Hydrogen Evolution with Hydrogenase Using Bipyridinium Salts as Electron Carriers
Authors: Okura Ichiro , Fujie Hiroki , Aono Shigetoshi , Kita Tatsuya , Kaji Naruhiko
Published: July 2006

Photoinduced hydrogen evolution was carried out by using bipyridinium salts as electron carriers. Hydrogen evolution rate strongly depends on the type of bipyridinium salt. The order of the rate values undergoes a change by the change in the rate-determining step.
Stopped-Flow Investigation of Antioxidant Activity of Tocopherols
Authors: Mukai Kazuo , Watanabe Yoshiko , Uemoto Yuichi , Ishizu Kazuhiko
Published: July 2006

It was observed by ESR measurement that the oxidation of α-, β-, γ-, and δ-tocopherols (vitamin E) with a stable phenoxyl radical in benzene immediately gives corresponding tocopheroxyl radicals. The rates of reaction of α-, β-, γ-, and δ-tocopherols with the stable phenoxyl radical in ethanol solution have been determined spectrophotometrically using stopped-flow technique, as a model reaction of tocopherols with unstable free radicals (ROO·, RO·, and HO·) in biological systems. The second-order rate constants obtained are (5.12±0.36)×103 (α-Toc), (2.24±0.04)×103 (β-Toc), (2.42±0.16)×103 (γ-Toc), and (0.51±0.01)×103 (δ-Toc), M−1 s−1 in ethanol at 25.0 °C. The relative rates agree well with those obtained from studies of the reactivities of tocopherols toward poly(styrylperoxyl) and galvinoxyl radicals by O2 consumption and by ESR method, respectively. The results suggest that the relative reactivities, that is, relative antioxidant activities of tocopherols do not depend on the kinds of unstable free radicals reacted.
Optically Active Cyclic Dipeptide Carrying 9-Anthryl Groups
Authors: Egusa Syun , Sisido Masahiko , Imanishi Yukio
Published: July 2006

Optically active 3-(9-anthryl)alanine was synthesized for the first time and its cyclic dipeptide, cyclo(d-9-anthrylalanine)2, was prepared. Conformation of the cyclic dipeptide in solution was investigated by means of 1H NMR, absorption, circular dichroism (CD), and fluorescence spectroscopy. The coupling parameter JNH-CαH, observed in the NMR spectra indicated a planar configuration for the 2,5-piperazinedione ring of the dipeptide. The cyclic dipeptide showed a moderately large exciton couplet in CD spectrum and a small splitting in the 1Bb absorption band, but no excimer emission in fluorescence spectrum. These spectroscopic data suggest an unfolded-unfolded conformation for the side chains of the cyclic dipeptide.
Oxidation of Lipids. XIV. Inhibition of Oxidation of Methyl Linoleate by Fatty Acid Esters of l-Ascorbic Acid
Authors: Takahashi Mareyuki , Niki Etsuo , Kawakami Akira , Kumasaka Akira , Yamamoto Yorihiro , Kamiya Yoshio , Tanaka Kunihiko
Published: July 2006

Various kinds of fatty acid esters of l-ascorbic acid were synthesized and their role as chain-breaking antioxidant was studied in the oxidation of methyl linoleate in homogeneous solution. Fatty acid esters of ascorbic acid at either 6- or both 5- and 6-positions were effective as antioxidant and suppressed the oxidation of methyl linoleate, whereas those having ester group at 2-position did not act as antioxidant. 5,6-Erythorbyl dipalmitate was also effective as an antioxidant. Ascorbic acid esters inhibited the oxidation cooperatively with α- and δ-tocopherols as observed for free ascorbic acid. The antioxidant activity was correlated with the reactivity toward galvinoxyl radical.
Synthesis of Unusual Aromatic l-Amino Acids by Asymmetric Hydrogenation of Cyclic Dehydrodipeptides
Authors: Aoyagi Haruhiko , Horike Fumio , Nakagawa Atsuko , Yokote Sayuri , Park Namgyu , Hashimoto Yoshihide , Kato Tetsuo , Izumiya Nobuo
Published: July 2006

To prepare l-Tyr(Me) and l-Amp (l-2-amino-5-(p-methoxyphenyl)pentanoic acid), their precursors cyclo(–ΔTyr(Me)–l-Ala–) and cyclo(–ΔAmp–l-Ala–) were hydrogenated in N,N-dimethylformamide. The content of Ll isomers in the hydrogenated products was over 94%. Mild acid hydrolysis of the hydrogenated products and subsequent recrystallization gave pure l-Tyr(Me) and l-Amp.
Mass Spectra of Tetrahydrofuran Derivatives
Authors: Nagano Hajime , Ijiri Makiko , Xu Xiao Hong , Shiota Michio
Published: July 2006

Mass spectra of 2-(4,5-dialkyloxacyclopent-2-yl)-2-propanols exhibited a characteristic cleavage of tetrahydrofuran ring yielding an ion at m⁄z 102 (C5H10O2) and/or an ion (M+–C5H10O2–H).
A Time-Resolved ESR Study on the Photochemical Reduction of Nitrobenzene Derivatives in Alcoholic Solution
Authors: Akiyama Kimio , Ikegami Yusaku , Ikenoue Tsuneo , Tero-Kubota Shozo
Published: July 2006

Time-resolved ESR experiments have been carried out to elucidate the initial process in the photochemical reduction of aromatic nitro compounds. The first observation of CIDEP due to nitrobenzene anion radicals in the presence of an electron donor proved that radical generation takes place through a triplet mechanism.
13C NMR Spectra of 1,3-Dithiolan-2-ylium Ions and 2-Alkylidene-1,3-dithiolanes
Authors: Okuyama Tadashi , Fueno Takayuki
Published: July 2006

13C NMR spectra of various 2-substituted 1,3-dithiolan-2-ylium perchlorates 5 as well as 2-alkylidene-1,3-dithiolanes 6 are measured. Chemical shifts induced by protonation of 6 to form 5 are compared with those found with the unsaturated analogues, 1,3-dithiolylium ions, implying the aromatic charge delocalization in the latter ions.
The Preconcentration and Separation of a Trace Amount of Copper(II) in Water as Its Silica-Immobilized Salicylaldimine Chelate by Means of Column Chromatography
Authors: Honjo Takaharu , Makino Tetsuji
Published: July 2006

The behavior of a trace amount of copper(II) in solid-liquid extraction and back extraction has been examined with silica-immobilized salicylaldimine; the results have also been applied to the preconcentration and separation of a trace amount of copper(II) in water as its silica-immobilized salicylaldimine chelate by means of column chromatography.
Surface Analysis of MF–Aluminas and Related Supported Reagents by Scanning Electron Microscopy
Authors: Ando Takashi , Clark James H , Cork David G , Kimura Takahide
Published: July 2006

SEM of MF–aluminas (M=Na, K, and Cs, loaded at 2 mmol g−1 and dried at 90 °C/2.7 kPa), showed similar salt dispersions and surface morphologies, with salt clusters of ca. 1 μm diameter evident on the external surfaces. Less reactive, highly dried or highly loaded, reagents showed extensive surface crystallization. KCl–and KOH–aluminas showed the effect of anion basicity, giving greater clustering and surface destruction respectively.
Synthesis of 1,3,6,8-Tetrakis(dimethylamino)pyrene Having Low Oxidation Potential
Authors: Ueda Naomi , Sakata Yoshiteru , Misumi Soichi
Published: July 2006

1,3,6,8-Tetrakis(dimethylamino)pyrene (1) was synthesized starting from the corresponding tetranitro compound. The first oxidation potential of 1 shows the lowest value (E1⁄21=−0.12 V vs SCE) among those of aromatic amines reported so far.
Electrochemical Properties of Adriamycin Adsorbed on Pyrolytic Graphite Electrodes Modified by Phospholipid Monomolecular Membranes
Authors: Konse Tomonori , Kano Kenji , Kano Rika , Kubota Tanekazu
Published: July 2006

Electrochemical equilibrium and kinetic parameters have been determined by means of numerical simulation of d.c. voltammograms based on the theory of a two-step surface-redox reaction for the case of the redox system of adriamycin adsorbed on a basal-plane pyrolytic graphite electrode (BPGE) which is modified by a phospholipid monomolecular membrane. Comparison of these parameters with those obtained at a bare BPGE has shown that thesemiquinone formation reaction is thermodynamically favorable and that the electron transfer rate constant decreases in these lipid membranes.
A Convenient One-Pot Synthesis of Acenaphthenequinones from 1-Acenaphthenones by NBS–DMSO Oxidation
Authors: Tatsugi Jiro , Okumura Shigeo , Izawa Yasuji
Published: July 2006

Acenaphthenequinone was obtained in 95% yield when the reaction of 1-acenaphthenone with N-bromosuccinimide was carried out in dimethyl sulfoxide at room temperature. Under similar conditions, several acenaphthenequinones were prepared from the corresponding 1-acenaphthenones in good yields.
The Structure of Diaquatris(1,1,1-trifluoro-2,4-pentanedionato)neodymium(III)–Acetone (1/1)
Authors: Nakamura Masao , Nakamura Reiko , Nagai Kiyofumi , Shimoi Mamoru , Tomoda Shuji , Takeuchi Yoshito , Ouchi Akira
Published: July 2006

The crystal and molecular structure of the title complex was determined by means of the singlecrystal X-ray diffraction method. The crystal of NdC18H22O9F9, F.W. 697.59, is orthorhombic, with a space group Pbna, a=22.068(5), b=22.293(4), c=11.020(2) Å, U=5421(2) Å3, Z=8, Dm=1.72(3), Dx=1.71 Mg m−3, and μ(Mo Kα)=20.46 cm−1. The central metal atom is octa-coordinated, being ligated with six β-diketonato and two water oxygen atoms, and is in a dodecahedral geometry. Two configurational isomers co-exist in the crystal, with the respective occupancy factors of 74 and 26%. In these isomers, the two chelate rings span in different ways; although the positions of all ligating oxygen atoms are the same, the chelates span two m-edges in one isomer and two g-edges in the other one.
Synthesis of New 1-Alkoxycarbonylamino-3-sulfonylpyrroles by Reaction of (Alkoxycarbonylazo)alkenes with β-Keto Sulfones
Authors: Attanasi Orazio , Filippone Paolino , Mei Amedeo , Santeusanio Stefania , Serra-Zanetti Franco
Published: July 2006

A mild, simple, and direct method for the synthesis of some new 1-alkoxycarbonylamino-3-sulfonylpyrrole derivatives by reaction of (alkoxycarbonylazo)alkenes with β-keto sulfones is reported.
Molecular and Crystal Structure of an Azobenzene-Linked Amphiphile, C33H54N3O3Br
Authors: Okuyama Kenji , Watanabe Hitoshi , Shimomura Masatsugu , Hirabayashi Kiyoshi , Kunitake Toyoki , Kajiyama Tisato , Yasuoka Noritake
Published: July 2006

Azobenzene-linked, single-chain ammonium amphiphile (C12AzoC5N+Br−), C33H54N3O3Br, was crystallized from their solutions in water and ethanol. The crystals are triclinic with the space group P\bar1, Z=2, a=3.4243(6), b=0.8525(1), c=0.6073(1)nm, α=73.45(1), β=88.03(1), and γ=93.32(1)°. The structure was solved by the direct method and refined anisotropically by the block-diagonal least-squares procedure: R=0.06 for 2917 observed reflections (2θ<105°, Cu Kα, λ=0.154184 nm). The crystal structure consists of regularly stacking bimolecular layers in which C12AzoC5N+Br− molecules incline about 30° to the layer surface. As expected from spectroscopic analyses, the azobenzene chromophore shows a head-to-tail (J-like) aggregation between adjacent molecules. The pronounced planarity of the azobenzene chromophore found in this crystal structure enables parallel stacking of phenyl groups in the J-like aggregation.
Fluorescence and Nonradiative Relaxation from Vibronic Levels of S1 Pyrimidine: Effects of Molecular Rotation and Intramolecular Vibrational Redistribution
Authors: Sekiguchi Osamu , Ohta Nobuhiro , Baba Hiroaki
Published: July 2006

Emission characteristics of pyrimidine vapor which were measured after excitation into various S1 vibronic levels with relatively low excess vibrational energies (ΔE) below 2650 cm−1 were found to depend markedly upon ΔE. The emission from a vibronic level with ΔE<1000 cm−1 (e.g., 6a1 or 11) is sharp and attributable to the fluorescence from the initially prepared vibronic level (IPL), and that from a vibronic level with ΔE>1000 cm−1 (e.g., 121, 6a2, or 122) involves broad fluorescence besides the IPL fluorescence. At low pressure, the broad fluorescence consists of fast and slow components with lifetimes comparable to those for the corresponding components of the IPL fluorescence. The broad fluorescence exhibits another slow component which is characterized by a less tendency to undergo collisional quenching. The quantum yield of the slow component of the IPL fluorescence clearly depends upon molecular rotation, whereas that of the broad fluorescence appears to show little or no rotational-level dependence. On the basis of these observations, the broad fluorescence is assigned to the one originating from S1 vibronic levels that can be reached directly from the IPL through intramolecular vibrational redistribution (IVR) or indirectly via triplet levels. There exists no evidence to show that the IVR is affected by molecular rotation.
129I Mössbauer Spectroscopic Studies of Tetrathiafulvalene–Iodine Charge-Transfer Salts
Authors: Sakai Hiroshi , Mizota Manabu , Maeda Yutaka
Published: July 2006

The Mössbauer effect of 129I has been applied to investigate tetrathiafulvalene–iodine (TTF–In) charge-transfer salts at 16 K. The electrically conductive TTF–I0.71 salt shows a broad single-line with the isomer shift of −0.36 mm s−1, suggesting that the iodine atoms on the average are not completely ionic (I−1.0) but are negatively charged by about 0.9 (I−0.9) in the low temperature phase. This is due to the weak interactions of the iodine atoms with the sulfur atoms of the TTF molecules. This fact is consistent with the crystallographic data and the electron spin resonance spectra of the salt. This salt is recognized as a partially oxidized mixed-valence compound. The spectrum of the TTF–I3 salt consists of two sets of quadrupole octets, corresponding to the central and terminal iodine atoms of the slightly distorted I3− ion. The charge density localized on each iodine atom of the I3− ion is close to that of the isolated I3− ion. That is, the salt is regarded as a simple ionic compound, for which a high electrical conductivity can not be expected. It is confirmed that a small amount of the TTF–I2 salt coexists in the TTF–I0.71 phase obtained from the solution of excess TTF and iodine. In the salt the iodine atoms exist as polyiodides consisting predominantly of I3− units.
High-Temperature Reaction of NH3–N2O System in Shock Waves
Authors: Fujii Nobuyuki , Uchida Syuji , Sato Hisaaki , Fujimoto Shiro , Miyama Hajime
Published: July 2006

The high-temperature reaction of NH3 with N2O in shock waves was investigated by measuring ultaviolet absoption of NH3 and OH, and infrared emission of N2O, in the temperature range of 1700–2300 K on the mixture of NH3–N2O diluted with large amount of argon. A comparison of the observed decays of NH3 and N2O and the formation of OH with those obtained by computer simulation behind the incident shock wave was carried out. From the comparison, the rate constants of the following elementary reactions were determined: NH3+O→NH2+OH[k4=1012.5exp(−25.5 kJ⁄RT) cm3 mol−1 s−1]; NH3+OH→NH2+H2O[k5=1012.5exp(−8.4 kJ⁄RT) cm3 mol−1 s−1].
X- and Q-Band ESR Studies of Binuclear Copper(II) Complexes with 3-Alkyl-2-pyridone Bridging Ligands
Authors: Goodgame David M L , Nishida Yuzo , Winpenny Richard E P
Published: July 2006

The ESR spectra of polycrystalline samples of bis(N,N-dimethylformamide)tetrakis(3-ethyl-2-pyridonato)dicopper(II) and its 3-methyl-2-pyridone analogue have been measured at X-band (≈9.5 GHz) and Q-band (≈34 GHz) frequencies. The spectra are characteristic of S=1 species and the parameters (gz 2.30, gxy 2.05 and D≈0.29 cm−1) are discussed in terms of the known binuclear structure.
The Precipitation of Monodispersed α-Iron(III) Oxide Particles from Iron(III) Chloride–Glycine System in Aqueous and 2-Propanol/Water Media
Authors: Hamada Shuichi , Niizeki Shin , Kudo Yoshiyuki
Published: July 2006

Monodispersed α-iron(III) oxide (hematite) particles were prepared by aging iron(III) chloride solutions in the presence of glycine at elevated temperatures, 98–100 °C. An aqueous solution of glycinatoiron (III) complex directly gave monodispersed double spheres of hematite, ≈4 μm in size, under the specified conditions, for example, 2.0×10−2 mol dm−3 FeCl3, 0.60 mol dm−3 glycine, and 0.46 mol dm−3 HCl for 96 h. The hematite particles grew up through the polynuclear layers mechanism. By the forced hydrolysis in 2-propanol/water mixed solution of 30% by volume, monodispersed cuboidal hematite particles, 0.06–0.43 μm in size, were also obtained through the conversion of β-iron(III) hydroxide oxide previously deposited. The nucleation rate was markedly affected by acidity at the latter case. The formation processes of these monodispersed hematite particles are discussed.
Interfacial Phenomena in the Extraction Kinetics of Nickel(II) with 2′-Hydroxy-5′-nonylacetophenone Oxime
Authors: Watarai Hitoshi , Takahashi Manabu , Shibata Kiyoji
Published: July 2006

The interfacial adsorption of (E)-2′-hydroxy-5′-nonylacetophenone oxime and its role in the extraction kinetics of the nickel(II) ion with the oxime were investigated in heptane/aqueous phase systems by means of a high-speed stirring apparatus. The interfacial oxime concentration was correlated to the organic phase concentration, obeying the Langmuir isotherm. The interfacial activity of the oxime was also measured by means of interfacial tension measurements. The initial extraction rate of nickel(II) ion was linearly proportional to the interfacial concentration of the oxime (rather than to the bulk-phase concentration), to the nickel-ion concentration, and inversely to the hydrogen-ion concentration. These results supported the mechanism that the rate-determining step in the extraction is the 1:1 complex formation at the interface.
The Photochemical Formation of the π-Cation Radical from Chloro(5,10,15,20-tetraphenylporphyrinato)cobalt(III) in Aerated Dichloromethane
Authors: Yamamoto Kiyoko , Hoshino Mikio , Kohno Masahiro , Ohya-Nishiguchi Hiroaki
Published: July 2006

Chloro(5,10,15,20-tetraphenylporphyrinato)cobalt(III), CoIII(tpp)Cl, in an aerated dichloromethane(DCM) solution undergoes photooxidation to produce the porphyrin π-cation radicals, CoIII(tpp)+·Cl2. The formation mechanism of the π-cation radical was investigated by means of optical absorption and ESR spectroscopy: CoIII(tpp)Cl in DCM decomposes photochemically to yield CoII(tpp) and chlorine atoms, which then abstract hydrogen atoms from DCM molecules to yield solvent radicals, ·CHCl2, and HCl. The solvent radicals react with oxygen molecules, resulting in the generation of peroxyl radicals, which then oxidize CoIII(tpp)Cl to produce the π-cation radicals, CoIII(tpp)+·Cl2.
Regio- and Stereochemistry of Bromochlorinations of Alkynes with Molecular Bromine Chloride and Dichlorobromate(1−) Ion
Authors: Negoro Takeshi , Ikeda Yoshitsugu
Published: July 2006

The bromochlorination of phenyl- and alkyl-substituted acetylenes with tetrabutylammonium dichlorobromate(1−) (1) in dichloromethane was found to be anti-stereospecific and nonregiospecific (regiospecific in the case of phenylacetylene). Whereas the addition of molecular bromine chloride (2) to phenyl-substituted acetylenes was found to give nonstereospecific and regiospecific adducts, the reaction of alkyl-substituted acetylenes gave anti-stereospecific and nonregiospecific adducts. These results suggest that the addition of 1 involves an attack of chloride ion to a three-centered π-complex in the product-forming stage, and that the addition of 2 to phenyl-substituted acetylenes involves a vinyl cation intermediate (but a bridged bromonium ion intermediate in the case of alkyl-substituted acetylenes).
Bromochlorination of Alkenes with Dichlorobromate(1−) Ion. V. Regio- and Stereochemistry for the Bromochlorination of Styrene Derivatives with Dichlorobromate(1−) Ion in Protic Solvents
Authors: Negoro Takeshi , Ikeda Yoshitsugu
Published: July 2006

The bromochlorination of styrene derivatives with tetrabutylammonium dichlorobromate(1−) (1) in such protic solvents as acetic acid and methanol gives the corresponding bromo chloro adducts along with substantial amounts of solvent-incorporated products in a regiospecific manner (regioselective in the case of 3-nitro- or 2-chlorostyrenes). The reaction of 1-phenylpropenes with 1 gives nonstereospecific but regiospecific adducts. These results suggest that the addition of 1 to styrene derivatives in protic solvents involves an attack of chloride ion or solvent molecule to a bromonium ion intermediate.
Synthetic Approach toward Antibiotic Ezomycins. II. Synthesis of 5-Amino-3,7-anhydro-5-deoxyoctofuranose-(1,4) Derivatives
Authors: Sakanaka Osamu , Ohmori Takashi , Kozaki Shuji , Suami Tetsuo
Published: July 2006

A conversion of 5-acetamido-5-deoxy-1,2:7,8-di-o-isopropylidene-3-o-methylthiomethyl-β-l-erythro-d-allooctofuranose-(1,4) and -l-talooctofuranose-(1,4) to 5-amino-3,7-anhydro-5-deoxyoctofuranose-(1,4) derivatives has been investigated as a preliminary study for a synthesis of the octose moiety of ezomycins.
Infrared C–D Stretching and 2H NMR Spectra of Isopropyl-2-d 1-(p-Substituted Phenyl)ethyl Ketones. Evidence for the Hydrogen Bond-Like Interaction between C–D Group and Aromatic π-Electrons
Authors: Karatsu Makoto , Suezawa Hiroko , Abe Kazuhisa , Hirota Minoru , Nishio Motohiro
Published: July 2006

Isopropyl-2-d 1-(p-X-phenyl)ethyl ketones (where, X=H, NO2, Br, Cl, C2H5, CH3, and NH2) were shown to have two absorption bands in the C–D stretching region. The absorption band at the higher frequency (ca. 2177 cm−1) is assigned to the C–D···π approached conformer, and the high frequency shift is ascribed to the effect of steric compression. Weak C–D···π hydrogen bond was shown to occur by the measurement of the substituent effect on the formation constant and the relative enthalpy of the C–D···π approached conformer.
A Study of the Zero Field Splittings of the Lowest Excited Triplet States of Substituted Benzenes and Related Molecules by Optical Detection of Magnetic Resonance, Electron Paramagnetic Resonance, and Molecular Orbital Calculations
Authors: Nagaoka Shin-ichi , Harrigan Edward T , Noda Masayo , Hirota Noboru , Higuchi Jiro
Published: July 2006

The zero field splittings of a series of substituted benzenes and related molecules have been examined by means of optical detection of magnetic resonance (ODMR), electron paramagnetic resonance (EPR), and molecular orbital (MO) calculations. It is experimentally shown that D and E values vary remarkably depending on the type of molecule despite the similarlity in the molecular size. In particular, E varies from +0.038 cm−1 for phenylacetylene to −0.0597 cm−1 for aniline reflecting large differences in the spin distributions. The calculation of the zero field splittings of the molecules studied here on the basis of the Pariser-Parr-Pople-type MO’s can give the values reasonably close to those obtained experimentally with a few exceptions. On the basis of the obtained results the natures of the T1 states of substituted benzenes are characterized from the zero field splittings.
Conformations in the Solid State and Solubility Properties of Protected Homooligopeptides of Glycine and β-Alanine
Authors: Narita Mitsuaki , Doi Masamitsu , Kudo Koji , Terauchi Yusuke
Published: July 2006

IR spectroscopic conformational analyses of Boc–Glyn–OBzl (n=3–7) and Boc–(β-Ala)n–OBzl (n=3–8) were performed in the solid state, suggesting the occurrence of the β-sheet structure in the higher oligomers (n=5–8). Solubility data indicate that insolubilities of Boc–Glyn–OBzl and Boc–(β-Ala)n–OBzl in high-polar solvents begin at hexa- and heptapeptide levels, respectively. Insolubility of protected homooligopeptides of Gly and β-Ala was estimated to be caused by β-sheet aggregation. The high potential for the β-sheet formation of Boc–Glyn–OBzl and Boc–(β-Ala)n–OBzl (n≥5) could clearly be attributed to the great freedom of the peptide backbone dihedral angles of each of the Gly and β-Ala residues in the β-sheet structure. The implications of a replacement of a few Gly residues with β-Ala residues in surface regions of proteins are also discussed.
Dehydrooligopeptides. VII. Convenient Synthesis of Various Dehydrodi- and tripeptide Esters by Using N-Carboxy α-Dehydroamino Acid Anhydride
Authors: Shin Chung-gi , Yonezawa Yasuchika , Ikeda Masahiro
Published: July 2006

The one-pot syntheses of N-protected Δ1- and Δ2-dehydrodipeptide esters by the coupling of N-carboxy α-dehydroamino acid anhydride (ΔNCA) with several kinds of C- or N-protected l-α-amino acids are described. In addition, it was found that a similar coupling of ΔNCA with both C- and N-protected α-amino acids also took place to give Δ2-dehydrotripeptide derivatives, involving eight kinds of important C-terminal segments of antrimycins and cirratiomycins. The configurational confirmation of the α-dehydroisoleucine residue of the antibiotics is also discussed.
Restricted Rotation Involving the Tetrahedral Carbon. LIX. Stereodynamics of Singly peri-Substituted 9-(3,5-Dimethylphenoxy)triptycene Derivatives
Authors: Yamamoto Gaku , Oki Michinori
Published: July 2006

Five singly peri-substituted derivatives of 9-(3,5-dimethylphenoxy)triptycene with F, OCH3, CH3, Br, and C(CH3)3 as the peri-substituent were synthesized and their dynamic NMR behavior was studied. In any of the compounds, two m-methyl groups in the phenoxyl moiety were anisochronous at low temperatures and the signals coalesced into a single peak on raising the temperature. Lineshape analysis afforded the energy barriers to the rate process ranging from 10.1 kcal mol−1 (1 calth=4.184 J) for the F compound to 17.6 kcal mol−1 for the C(CH3)3 one. Molecular mechanics calculations (MM2) were performed on closely related model compounds to obtain the relative steric energies of the ground states and the possible transition states. The results from the dynamic NMR and the molecular mechanics studies suggest the following: When the peri-substituent is small (F and OCH3), the complete gear rotational circuit with the passing of the aryl group over the peri-substituent as the rate-determining step is the lowest-barrier process, while when the peri-substituent is bulky (CH3, Br, and C(CH3)3), the “isolated” rotation of the aryl group at the ap site has a lower barrier and is responsible for the observed dynamic NMR behavior. In the 1,3-di-t-butyl derivative, restricted rotation of the 1-t-butyl group was observed below −75 °C, the free energy of activation being 9.5 kcal mol−1.
α-Fluorination of Sulfides with N-Fluoropyridinium Triflates
Authors: Umemoto Teruo , Tomizawa Ginjiro
Published: July 2006

The reaction of sulfides possessing α-hydrogen with various N-fluoropyridinium salts was examined. While the fluorinating power increased in the order of N-fluoro-2,4,6-trimethylpyridinium triflate 1<N-fluoropyridinium triflate 22, and 3 no longer produced the α-fluoro sulfide. Triflate 1 was more reactive than the corresponding tetrafluoroborate 4. Thus, it was shown that 1 satisfactorily fluorinated various kinds of sulfides under very mild conditions, giving α-fluoro sulfides. A two-step mechanism, oxidative fluorination of sulfur and Pummerer-type rearrangement, was proposed for the fluorination. The corresponding α-fluoro sulfoxide or sulfones were easily prepared from the sulfides by successive fluorination–oxidation procedure.
Structure and Optical Spectrum of (TMTTF)2IO4. The Role of Coulomb Interaction
Authors: Yakushi Kyuya , Aratani Sukekazu , Kikuchi Koichi , Tajima Hiroyuki , Kuroda Haruo
Published: July 2006

The semiconductive (TMTTF)2IO4 salt was prepared by using the electrochemical method. The crystal structure was determined to be isomorphous to the metallic (TMTTF)2X salts. The polarized infrared reflectance spectra of (TMTTF)2IO4 and (TMTTF)2BF4 were measured and were interpreted on the basis of the extended Hubbard model.
Viscosity B Coefficients for N,N′-Polymethylenebis(trialkylammonium) Dibromides in Aqueous Solutions
Authors: Tamaki Kunio , Horii Goro , Chida Takashi , Ochiai Keiko , Kadokura Yoshiyuki
Published: July 2006

The viscosity B coefficients for aqueous solutions of N,N′-polymethylenebis(trialkylammonium) dibromides [(CmH2m+1)3N(CH2)nN(CmH2m+1)3]Br2 (m=2–4, n=3–6, 8, 10, and 12) and, for comparison, of CnH2n+1N(CmH2m+1)3Br (m=2, n=1–6; m=3,4, n=2–6) have been determined at 25 and 35 °C. The effect of structural changes in the solvent water upon the dissolution of these homologous electrolytes is discussed.
Determination of a Small Amount of a Biological Constituent by Use of Chemiluminescence. VIII. Effect of Heating on the Determination of Protein
Authors: Hara Tadashi , Tsukagoshi Kazuhiko , Arai Akihiro , Iharada Takeshi
Published: July 2006

The effect of heating on the determination of protein by chemiluminescence was examined by estimating the apparent coupling constant of a copper(II)–protein complex after treatment of a solution at 25 °C or 95 °C and by comparing the values with each other. The values obtained for two proteins were as follows: 1.3×108 mol−1 dm3–2.1×1011 (mol−1 dm3)1.5 at 25 °C and 4.3×1017 (mol−1 dm3)2.3–1.9×1018 (mol−1 dm3)2.2 at 95 °C. These values suggest that heating makes a copper(II)–protein complex more stable and improves the concentration range for the determination of protein.
Catalytic and Electrocatalytic Hydrogenation of Benzylideneazlactone and Benzylidenehydantoin
Authors: Matsue Tomokazu , Yamada Tsukasa , Takahashi Hiroko , Osa Tetsuo
Published: July 2006

The electrocatalytic hydrogenatoin of benzylideneazlactone and 5-benzylidenehydantoin with Raney-nickel cathode proceeded smoothly to afford N-acetylphenylalanine and 5-benzylhydantoin, respectively. In addition, refluxing the electrolyte solution after the electrolysis finally yielded phenylalanine with satisfactory chemical yields and current efficiencies. This electrocatalytic process showed slightly higher reactivity than the ordinary catalytic hydrogenation.
A Supercritical Carbon Dioxide Extraction from Mackerel (Scomber Japonicus) Powder: Experiment and Modeling
Authors: Ikushima Yutaka , Saito Norio , Hatakeda Kiyotaka , Ito Shota , Asano Takashi , Goto Tomio
Published: July 2006

The extraction of some organic substances from freezed-dried mackerel powder was performed using supercritical carbon dioxide (SC–CO2) at 4.9–24.5 MPa and 313 K in a fixed-bed flow extractor. It was found that the rate of extraction was enhanced by raising the pressure. The overall yield of the SC–CO2 extraction was comparable to that of a hot-hexane-extraction from the same material. The SC–CO2 extraction produced glycerides of pharmacologic significance such as icosapentaenoic acid (IPA) and docosahexaenoic acid (DHA) from mackerel. In addition, a kinetic model for extraction with supercritical fluids is described, and is applied to correlate our results obtained in the SC–CO2 extraction of mackerel. This model could express the transport within the solid in the supercritical fluid extraction process.
An Analysis of the Voltammetric Adsorption Waves of Methyl Viologen
Authors: Kobayashi Katsuyoshi , Fujisaki Fumiaki , Yoshimine Toshifumi , Niki Katsumi
Published: July 2006

The electrochemical behavior of 1,1′-dimethyl-4,4′-bipyridinium dichloride (methyl viologen, MV) is complicated with the strong adsorption of both the oxidized (MV2+) and the reduced (MV+·) forms of MV on a mercury electrode. MV2+ adsorbs on the electrode with a flat orientation at more positive potentials than the potential of zero charge of the mercury electrode. MV+· adsorbs on the electrode with a vertical orientation at more negative potentials than the formal potential of the MV2+⁄+· couple, (E0′)MV. It is probable that the change in the orientation of the adsorbed MV+· from flat to vertical with the increase in the MV+· concentration in the vicinity of the (E0′)MV leads to a strongly attractive interaction between the adsorbed MV+· molecules and a sharp voltammetric adsorption peak results at higher concentrations of MV2+.