bluuebunny/crossref_metadata_2025 huggingface dataset:
The Reaction of Acetophenones with Manganese(III) Acetate
Authors: Kurosawa Kazu , Yamaguchi Katsutoshi
Published: July 2006

The reaction of 4′-methoxyacetophenone with manganese(III) acetate in the presence of ammonium chloride yielded 2-chloro-4′-methoxyacetophenone (2a) and 2,2-dichloro-4′-methoxyacetophenone (3a). The reaction of 2a with these reagents gave 3a, 4′-methoxy-2,2,2-trichloroacetophenone, and 1,4-bis(4-methoxyphenyl)-2,2,3,3-tetrachloro-1,4-butanedione (8a). The reactions of 2a and 2-bromoacetophenone with manganese (III) acetate yielded the corresponding 2,3-dihalo-1,4-diphenyl-1,4-butanediones, 1,4-diphenyl-2-halo-2-butene-1,4-diones, 2,3-dihalo-2-butene-1,4-diones, 2,2-dibromoacetophenone, and 8a. The reaction pathways are discussed.
A Convenient Synthesis of Condensed Cyclopentane System. Annelation by Intramolecular 1,3-Dipolar Addition of Nitrones
Authors: Takahashi Satoru , Kusumi Takenori , Sato Yoko , Inouye Yoshinobu , Kakisawa Hiroshi
Published: July 2006

Intramolecular 1,3-dipolar addition reactions of nitrones were investigated. Four alkenyl nitrones were studied: 2-allyl-, 2-(3-butenyl)-, 2-(4-pentenyl)-, and 2-(9-decenyl)-N-methylcyclohexanimine N-oxides. Among these, 2-(3-butenyl)-N-methylcyclohexanimine N-oxide was found to cyclize most smoothly, giving a perhydroindene derivative as a single regio- and stereoisomer. A perhydroazulene derivative was obtained by cyclization of 2-(3-butenyl)-N-methylcycloheptanimine N-oxide.
Electronic Structures of Uracil and Its Anions
Authors: Morita Hiroshi , Kwiatkowski Józef S , Tempczyk Anna
Published: July 2006

Electronic structures of uracil and its anions were theoretically investigated by a modified CNDO-CI method. Theoretical results were in good agreement with the observed spectra of uracil and of both the uracil-3-ide and uracil-1-ide anions, indicating that the second π-π* band of uracil may tentatively be assigned to the 215 nm band observed in circular dichroism spectrum, and that the lowest singlet and triplet states of uracil are n-π* and π-π* states, respectively, in accord with the observed solvent dependence on emission properties. The first π-π* band of uracil-1-ide anion was correctly predicted by the method at longer wavelengths than the corresponding band of uracil-3-ide anion. For the purpose of comparison, a modified INDO-CI, CNDO/S-CI, and a modified π-SCF-MO-CI methods were also applied to the molecules under consideration. The results were only partly successful in predicting the observed spectra.
The Aluminium Ion-assisted Aquation of [CoF(NH3)5]2+
Authors: Iida Masayasu , Kai Eiko , Nishimoto Kichisuke , Yamatera Hideo
Published: July 2006

A kinetic study of the aluminium ion-assisted aquation of CoF(NH3)52+ was carried out. The pseudo-first order rate constant obtained can be expressed as kobsd=kAl[Al3+], where kAl=(1.6±0.2)×10−3 dm3 mol−1 s−1(I=2.0 mol dm−3, 25 °C). The reaction rate is independent of the pH in the (pH)obsd<3.3 range, in contrast with the pH-dependent rate for the CrF(NH3)52+-Al3+ system. The different behavior between CoF(NH3)52+ and CrF(NH3)52+ in aquation can be explained in terms of their electronic structures, as calculated on the basis of the CNDO/2 method.
Structural Studies on the Cyclic Carbamate Derivatives of Kanamycin A
Authors: Takagi Yasushi , Komuro Chikara , Tsuchiya Tsutomu , Umezawa Sumio
Published: July 2006

Treatment of tetrakis(N-benzyloxycarbonyl)-6″-O-tritylkanamycin A with sodium hydride in N,N-dimethyl-formamide, followed by chromatography, afforded 4′,6′ : 3″,4″-, and 4′,6′ : 2″,3″-bis(cyclic carbamate) and 3″,4″-and 2″,3″-mono(cyclic carbamate) (2, 3, and others). The structures of the position isomers 2 and 3 were determined by the NMR spectra at 500 MHz of their N-tosyl-O-acetyl derivatives.
Syntheses of N-Substituted 3,3,4-Triaryl- and 3,3,4,4-Tetraphenyl-2-azetidinones
Authors: Mehrotra Kailash Nath , Singh Surendra Bahadur
Published: July 2006

The reactions of 2-diazo-1,2-diphenylethanone with Schiff’s bases Ar–CH=N–R gave new substituted 2-azetidinones together with 1,1′,4,4′-tetraphenyl-2,2′-azinodiethanone. 2-Diazo-1,2-diphenylethanone reacts with N-benzhydrylidene-N′-phenylurea to give 1-(phenylcarbamoyl)-3,3,4,4-tetraphenyl-2-azetidinone.
Dielectric Relaxation Processes in Some Substituted Amides in Dilute Solutions
Authors: Saxena S K , Shukla J P , Saxena M C
Published: July 2006

The dielectric measurements have been carried out in the microwave region (3.1 cm) over a range of temperatures on propionamide, N-methylpropionamide, N,N-dimethylpropionamide, and N-ethylacetamide. All the molecules except propionamide exhibit high value of distribution parameter. The dielectric dispersion, when resolved by Higasi, Koga, and Nakamura method gives two relaxation times τ(1) and τ(2) widely different from each other, suggesting the two separate processes occurring in the system. The enthalpies for different processes involved have been evaluated by the Eyring equations. The comparison with NMR data of enthalpy to ΔHτ(1), which is related to the process other than molecular, suggests that the rotation of–NR2 group around the carbonyl carbon nitrogen bond is not feasible. The observed result indicates that this may be due to group inversion process. These results are in agreement with the earlier investigations of Saxena et al. on some substituted amides and of Phillips on N,N-dimethylamide using proton resonance spectra. The substituted amides in dilute solution of benzene exhibit some association with the benzene molecules.
Kinetics of the Hydrolysis of Zeolite 4A Surface by the Pressure-jump Relaxation Method
Authors: Ikeda Tetsuya , Sasaki Minoru , Astumian Raymond D , Yasunaga Tatsuya
Published: July 2006

Single relaxation was found in the basic zeolite 4A suspension by the pressure-jump method. The relaxation phenomenon was attributed to the hydrolysis of the zeolite 4A surface and the kinetic parameters were obtained.
Dual-wavelength Spectrophotometric Determination of Trace Amounts of Phosphate in the Presence of Large Amounts of Silicate Using Molybdenum Blue
Authors: Ohashi Kousaburo , Enomoto Toshie , Yamamoto Katsumi
Published: July 2006

A method is described for the determination of trace amounts of phosphate in the presence of large amounts of silicate. It is based on the difference in the absorption spectra of molybdenum blues formed from phosphate and silicate using a dual-wavelength spectrophotometer. The difference in absorbances at 797.3 nm and 825.0 nm is proportional to phosphate concentration over the range 1.60×10−7 to 7.00×10−5 M (1 M=1 mol dm−3).
α-Glucosylation of Phenols with Tetra-O-benzyl-α-d-glucose
Authors: Koto Shinkiti , Morishima Naohiko , Araki Mihoko , Tsuchiya Takuji , Zen Shonosuke
Published: July 2006

An α-glucosylation of phenols with 2,3,4,6-tetra-O-benzyl-α-d-glucopyranose is described. This uses a mixture of p-nitrobenzenesulfonyl chloride, silver trifluoro-methanesulfonate and triethylamine in dichloromethane in a two-stage treatment.
Homogeneous Hydrogenation of α,β-Unsaturated Ketones and Aldehydes Catalyzed by Co2(CO)8–Di(tertiary phosphine) Complexes
Authors: Murata Kazuhisa , Matsuda Akio
Published: July 2006

The cobalt complexes modified by some di(tertiary phosphine)s as ligands were found to be much more active catalysts than Co2(CO)8 for the hydrogenation of α,β-unsaturated ketones and aldehydes under hydroformylation conditions.
The Stability of the Supersaturation State in Optical Resolution by the Preferential Crystallization Procedure
Authors: Hongo Chikara , Yamada Shigeki , Chibata Ichiro
Published: July 2006

In the optical resolution process of Dl-serine m-xylene-4-sulfonate dihydrate by the preferential crystallization procedure, the stability of the supersaturation state of the unseeded isomer was investigated in connection with the cooling conditions. The experiment was initiated with the model solution and was then extended to the actual resolution process. The metastable region of the unseeded isomer on a two-dimensional diagram with the supersaturation degree and cooling time could be divided into the first and the second metastable regions. The limits of the first and the second metastable regions were expressed by a supersaturation degree and by an area on the diagram respectively. Both limiting values were constant, independent of cooling speed and the lowest arrival temperature, if the conditions for the crystallizer, the initial concentration of the Dl-form, the amount of the seed crystals, and the degree of stirring were fixed.
The Prediction of the Optical Resolution Process by the Use of the Preferential Crystallization Procedure
Authors: Hongo Chikara , Yamada Shigeki , Chibata Ichiro
Published: July 2006

In the optical resolution of Dl-serine m-xylene-4-sulfonate dihydrate by the preferential crystallization procedure, the prediction of the resolution process was studied. The solution saturated with the Dl-form at 20 °C was cooled under a programmed cooling pattern and was seeded with the l-isomer. The decrease in the concentration of the l-isomer during the process was predicted by a conventional calculation method. Then, the waiting time for the spontaneous crystallization of the d-isomer was predicted by using the limiting values of the first and the second metastable regions, which were discussed in a previous report. As a result, a good agreement was obtained between the predicted results and the experimental results.
NQR Zeeman Study of Bis(triphenylphosphine)copper(I) Bromide
Authors: Okuda Tsutomu , Hiura Morio , Negita Hisao
Published: July 2006

Zeeman effects of 63Cu and 81Br NQR spectra of bis(triphenylphosphine)copper(I) bromide, CuBr(PPh3)2, have been studied at room temperature. The asymmetry parameters and the quadrupole coupling constants (e2Qq⁄h) have been found to be 0.113 and 64.58 MHz for 63Cu and 0.518 and 105.91 MHz for 81Br. The large asymmetry parameter of the 81Br NQR line is caused by the π-bonding character of the copper-bromine bond. The bonding scheme between the copper and bromine atoms is discussed on the basis of the obtained directions of the electric field gradient axes.
Polarized Absorption and Reflection Spectra of the Single Crystals of 11,11,12,12-Tetracyano-2,6-naphthoquinodimethan (TNAP) Complexes
Authors: Yakushi Kyuya , Sato Yoshiyuki , Ikemoto Isao , Kuroda Haruo
Published: July 2006

The electronic absorption spectra of 2,6-bis(dicyanomethylene)-2,6-dihydronaphthalene (11,11,12,12-tetracyano-2,6-naphthoquinodimethan; TNAP) and its anion radical (TNAP−) were studied. The absorption bands of the solution spectra of TNAP0 and TNAP− were successfully assigned to the electronic transitions which were calculated by the use of molecular orbital method. The polarized absorption and reflection spectra were measured on the single crystals of Na·TNAP and (methyltriphenylphosphonium)(TNAP)2 [(MTPP)(TNAP)2]. The low-lying electronic excitations of these complexes are quite similar to those of the corresponding tetracyano-quinodimethan (TCNQ) salts.
The Structure of the Cyclodextrin Complex. X. Crystal Structure of α-Cyclodextrin-Benzaldehyde (1 : 1) Complex Hexahyderate
Authors: Harata Kazuaki , Uekama Kaneto , Otagiri Masaki , Hirayama Fumitoshi , Ogino Hisashi
Published: July 2006

The crystal structure of the α-cyclodextrin–benzaldehyde (1:1) complex hexahydrate, C36H60O30·C7H6O·6H2O, was determined by the X-ray method. The crystal is monoclinic, the space group being P21 with Z=2. The cell dimensions are a=7.932(1), b=13.500(1), c=24.704(2) Å, and β=90.85(1)°. The structure was solved by means of a Patterson map and a trial-and-error method combined with the rigid-body least-squares technique. Refinement was carried out by the block-diagonal least-squares method to the final R-value of 0.057 for 4565 reflections. α-Cyclodextrin molecules are stacked along the a axis in a head-to-tail fashion to form a channel-type structure. The α-cyclodextrin ring is tilted by an angle of 11.5° against the channel axis. Adjacent α-cyclodextrin molecules along the channel are linked by hydrogen bonds between the primary hydroxyl groups and the secondary hydroxyl groups, and O(2)···water···O(6) hydrogen-bond bridges. The guest benz-aldehyde molecules are aligned inside the α-cyclodextrin column. The benzene ring is inserted into the α-cyclodextrin ring from the secondary hydroxyl side, while the carbonyl group is in the van der Waals contact with the primary hydroxyl side of the next α-cyclodextrin. The guest plane is nearly parallel to the channel axis, making an angle of 71.2° against the plane through six glycosidic oxygen atoms. Spaces between α-cyclodextrin columns are filled with water molecules. Many hydrogen bonds are observed among hydroxyl groups of α-cyclodextrin and water molecules, forming a hydrogen-bond network in the crystal.
On Some Mixed Chelates of Nickel(II) Which Are Highly Volatile, Fusible, and Soluble in Nonpolar Solvents
Authors: Saito Yoko , Takeuchi Toshio , Fukuda Yutaka , Sone Kozo
Published: July 2006

It was found that the mixed chelates of nickel (II) with the general formula [Ni(diam)(β-dik)2], where diam means an N,N- or N,N′-alkylated ethylenediamine and β-dik a β-diketonate anion, are highly volatile, fusible, and often amazingly soluble in nonpolar solvents like CCl4, benzene, or heptane. Representative data on these properties are presented and their correlations with the structures of the ligands are discussed.
Quantitative Interpretation of Infrared Diffuse Reflectance Spectra over Whole Concentration Range
Authors: Hattori Tadashi , Shirai Kenji , Niwa Miki , Murakami Yuichi
Published: July 2006

The infrared diffuse reflectance spectra of CaCO3 dispersed in KBr and Si were measured over a wide concentration range. The relation between relative reflectance and concentration varies with dispersing medium. The relation follows the Kubelka-Munk (K-M) equation only in the low concentration region. The deviation in the high concentration region from the K-M equation changes with wavelength and dispersing medium. The results over the whole concentration range can be interpreted by means of a modified K-M equation in which the difference in the scattering coefficients between the sample and the dispersing medium is taken into account. The tendency of scattering coefficients of CaCO3, KBr, and Si calculated by the modified Kubelka-Munk equation agrees with that of refractive indexes.
Chromatographic Behavior of Metalloporphyrins by Cellulose Thin-layer Chromatography
Authors: Onoue Yoshiaki
Published: July 2006

Cellulose thin-layer chromatographic separation of chlorophyll a, b, and c, pheophytin a, b, and c, Zn(II) and Cu(II)-complexes of protoporphyrin-IX dimethyl ester (PPDE) was studied by using a light petroleum–acetone developing solvent system. The hRf values of metal–PPDE chelates were found to be virtually linearly related with the electronegativities-to-radius ratio (En/ri) of central-metal ions. The hRf values of metalloporphyrins become progressively greater with increase in En/ri values of the central metal. This suggests that a dominant factor influencing the hRf values of metal–porphyrins is the extent of electron transfer from the four nitrogens and/or the π-electron system of porphyrin to central metal.
The Depth Profiling of Glass Surfaces by Mass Spectrometry Using Neutral-particle Bombardment
Authors: Iino Akira , Mizuike Atsushi
Published: July 2006

Glass surfaces are bombarded by energetic neutral argon atoms or oxygen molecules, and the resulting sputtered ions are mass-analyzed. This technique has a higher depth resolution than conventional secondary-ion mass spectrometry. Quantitative depth-concentration profiles of sodium and potassium in the top layer of the surface (within several tens of nanometers of the surface) of Pyrex glass are obtained by the proposed technique.
Kinetic and Equilibrium Studies on the Esterification of Monomeric and μ-Oxo Dimeric Vanadium(V) Complexes with Butyl Alcohols in Chlorobenzene
Authors: Yuchi Akio , Yagishita Yumi , Yamada Shinkichi , Tanaka Motoharu
Published: July 2006

Kinetic and equilibrium studies were made on the esterification of the μ-oxo dimeric vanadium (V) complexes with monoanionic bidentate ligands(HL) such as 8-quinolinol, 5-chloro-8-quinolinol, 5,7-dibromo-8-quinolinol, and 4-isopropyltropolone by butyl alcohols (ROH) in chlorobenzene. The stoichiometry and the rate equation are expressed as follows:

V2O3L4+2ROH\ightleftharpoons2VO(OR)L2+H2O:KDE;

−\fracd[V2O3L4]dt=\frac12×\fracd[VO(OR)L2]dt=(k1+k2[H2O])[V2O3L4][ROH].

The more basic the bound ligand L−, the lower the water-independent rate constant k1 is. For less sterically crowded alcohols, k1 is higher, giving the reactivity order: n->i->s->t-. Water, presumably hydrogen bonded to the terminal oxo group of the complexes, accelerates the esterification(k2 path). The equilibrium constant KDE is linearly correlated with the rate constant k1. The esterification kinetics of the monomeric complex with 2-methyl-8-quinolinol(HL′), which corresponds to the proposed reactive intermediate in the esterification of the μ-oxo dimeric complexes, is also investigated and found the rate equation to be expressed as

−\fracd[VO(OH)L′2]dt=\fracd[VO(OR)L′2]dt=kM,1[VO(OH)L′2[ROH].

k M,1 is 5 times higher than the estimated for the corresponding dimeric complex. Large negative values of ΔS1\eweq and ΔSM,1\eweq point to an associative nucleophilic attack of alcohol to the vanadium center of both dimeric and monomeric complexes. The difference of the reactivity of complexes and alcohols and the detailed mechanism will be discussed.
The Study of Transition-metal Complexes with Ethylenediamine and Cyano Ligands by Means of the X-Ray Photoelectron Spectra
Authors: Sano Mitsuru , Yamatera Hideo
Published: July 2006

The X-ray photoelectron spectra (XPS) were measured in order to obtain the Nls and Cls core-orbital energies of ten ethylenediamine and 21 cyano complexes of transition metals. The difference between the Nls and Cls energies, ΔE, which was found to be hardly affected by the counter ion or by charging, was accurately determined for each complex. The trends observed in the ΔE values for these series of complexes are correlated with the electronic structures of the complexes by the use of Siegbahn’s equation. For the ethylenediamine complexes, the ΔE values are shown to be related to the σ donation. For the cyano complexes, the ΔE values are mainly controlled by the nitrogen charge, which is itself closely connected with the π back-donation. Demonstrative of the importance of the π back-donation are the cases of [Fe(CN)6]4− and [Fe(CN)6]3−, where the decrease in the negative charge from the former to the latter is found to occur dominantly (76%) in the nitrogen atoms. Molecular orbital (MO) calculations in the discrete variational Xα (DV-Xα) scheme were performed for a few series of the cyano complexes, giving results consistent with the XPS results.
Substituent and Solvent Effects in the Reactions of Diaryldiazomethanes with 2,3-Dichloro-5,6-dicyanobenzoquinone
Authors: Oshima Takumi , Nagai Toshikazu
Published: July 2006

Kinetic studies have been made of the reactions of fifteen meta- and para-substituted diphenyldiazomethanes(DDMs) with 2,3-dichloro-5,6-dicyanobenzoquinone(DDQ) in benzene. The second-order rate constants, k, increased with the electron-donability of the substituents, and the value could be correlated with the Yukawa-Tsuno equation: logk⁄k0=−2.33(σ0+0.47Δ\barσR+)+0.017, (r=0.996,30 °C). The ρ value, −2.33, indicates the development of a positive charge at the diazo carbon in the transition state, while the R value, 0.47, confirms the moderate stabilization of the positive charge by the π-electronic contribution of the para substituents. The rate constants have also been determined for the reaction of diphenyldiazomethane(DDM) with DDQ in 28 aprotic solvents. The effects of solvents can be interpreted in terms of the basicity and the steric nature of the solvents. The products of these reactions were poly(2,3-dichloro-5,6-dicyanohydroquinone benzhydryl ether)s, which were easily convertible into benzophenones and α,α-dimethoxydiphenylmethane, together with 2,3-dichloro-5,6-dicyanohydroquinone, under the influence of water and methanol. These solvolysis products were also obtained in excellent yields in the initial presence of these additives.
Specific Catalysis by α-Cyclodextrin on the Dichlorocarbene Attack at Phenolate
Authors: Komiyama Makoto , Hirai Hidefumi
Published: July 2006

A selective attack of dichlorocarbene at the para-position of phenolate has been achieved by using α-cyclo-dextrin and the reaction mechanism has been studied by the 13C-NMR and 1H-NMR spectroscopy. The attack of the carbene at the para-position of phenolate (82%) is dominant over the attack at the ortho-position (18%) in the presence of 0.15 mol dm−3 of α-cyclodextrin, which is in contrast with the predominance of the ortho-attack (59%) over the para-attack (41%) in the absence of α-cyclodextrin.
The Reactions of Phenylmagnesium Halides with Seleninyl Chloride, Diphenyl Selenoxide, and Dibromodiphenylselenium
Authors: Iwama Yasunori , Aragi Masashi , Sugiyama Motohide , Matsui Kasumi , Ishii Yasutaka , Ogawa Masaya
Published: July 2006

Triphenylselenonium halides were readily prepared in good yields by the one-step reaction of seleninyl chloride with phenylmagnesium halides, followed by treatment with hydrogen halides. The yields of triphenylselenonium halides are markedly affected by the molar ratio of seleninyl chloride to the phenylmagnesium halides. In order to interpret the above results, some probable intermediates, such as diphenyl selenoxide, dibromodiphenylselenium, and diphenyl selenide, were investigated by allowing them to react with the phenylmagnesium halides. A pathway which consists of competitive and successive reactions is discussed.
Nucleophilic Cleavage of Phosphate Triesters in Dialkylammonium Bilayer Membranes
Authors: Okahata Yoshio , Ihara Hirotaka , Kunitake Toyoki
Published: July 2006

A study was carried out on the reaction of p-nitrophenyl phosphates with hydroxamate nucleophiles in water in the presence of dialkylammonium bilayer membranes. With ethyl bis(p-nitrophenyl) phosphate, clean second order kinetics was observed for all the hydroxamate nucleophiles, two equivalents of p-nitrophenol being released in most cases. In contrast, a complex kinetics was observed for octadecylbis(p-nitrophenyl)phosphate. The second cleavage process of this long-chain substrate by a long-chain hydroxamate was affected by the fluidity of the matrix membrane, an inflection region being present in the Arrhenius plots near the phase transition temperature(Tc) of the 2C16N+2C1 membrane. The activation energy was 14 and 21 kcal/mol at temperatures above and below Tc, respectively. Similar changes in the activation energy had been observed for decarboxylation and proton abstraction.
Synthesis of [3.3](1,1′)- and [5.5](1,1′)Ruthenocenophanes and Their Ferrocenoruthenocenophane Homologs
Authors: Kamiyama Shin-ichi , Kasahara Akira , Izumi Taeko , Shimizu Iwao , Watabe Hiroyuki
Published: July 2006

[3.3](1,1′)Ruthenocenophane-2,14-diene-1,16-dione, [5.5](1,1′)ruthenocenophane-2,14,17,29-tetraene-1,16-dione and their ferrocenoruthenocenophane homologs were synthesized by using an intermolecular base-catalyzed condensation.
Intramolecular Hydrogen Bonding and Conformations of α,α-Dialkyl- and α-Alkyl-o-methoxybenzyl Alcohols. II. Enthalpies of Hydrogen Bond Formation and Molecular Force Field Calculations on α-Alkyl-substituted Benzyl Alcohols
Authors: Ito Masayuki , Hirota Minoru
Published: July 2006

Enthalpies of intramolecular hydrogen bond formation (ΔH) were determined for a series of α-mono- and α,α-dialkyl-o-methoxybenzyl alcohols and related compounds. The −ΔH values of the unsubstituted and α,α-dialkyl-o-methoxybenzyl alcohols are more than 2.5 kJ mol−1, while those for the corresponding α-monoalkyl derivatives are at most 1 kJ mol−1. This tendency is in accordance with the results on their ΔvOH and εb/εf values, showing the hydrogen bonded conformations of the α-monoalkyl derivatives are less favorable than those of the other alcohols in discussion. Molecular force field calculations on α-alkyl- and α,α-dialkylbenzyl alcohols were also carried out. The results shows that the hydroxyl/aryl coplanar conformation (ω=0°) is the most stable for the unsubstituted and α,α-dialkylbenzyl alcohols and the hydroxyl/aryl non-coplanar conformation (ω=30°) for α-alkylbenzyl alcohols. Since the OH···O distance might be farther and, hence, the overlap between the unshared electron pairs on the methoxyl oxygen and the anti-bonding OH orbital might be less in the non-coplanar conformation, α-monoalkyl-o-methoxybenzyl alcohols are less favorable than the corresponding α,α-dialkyl derivatives in the intramolecular hydrogen bond formation.
Improvement of Furan Yield in Oxidation of Crotonaldehyde by Modifying 12-Molybdophosphoric Acid Catalysts
Authors: Tsai Tian-hsi , Ai Mamoru , Ozaki Atsumu
Published: July 2006

12-Molybdophosphoric acid effective for oxidation of crotonaldehyde to furan was modified in two ways; by adding various cations and by replacing Mo with V or W. Among cations caesium was proved to be most effective in improving the furan yield, by decreasing reactivity of product furan relative to crotonaldehyde, thus minimizing the secondary oxidation of furan to maleic anhydride. The highest efficiency of caesium is associated with its high basicity, while the active catalyst species responsible for the furan formation is acidic in nature. The replacement of Mo by V or W gave rise to decreased activity, in contrast to other oxidations on the same catalyst. The unique character of crotonaldehyde oxidation is discussed.
Electrochemical Oxidation-Reduction Properties of Covalently Bound FAD of Cholesterol Oxidase Adsorbed on Mercury Electrode Surface
Authors: Ikeda Tokuji , Ando Shinji , Senda Mitsugi
Published: July 2006

Cholesterol oxidase from Schizophyllum commune was studied by cyclic d.c. and a.c. voltammetry with a hanging mercury drop electrode. The enzyme gave d.c. and a.c. waves due to covalently bound FAD of the enzyme adsorbed on an electrode surface. The waves were interpreted in terms of d.c. and a.c. voltammetry of a twostep surface redox reaction. The standard surface oxidation-reduction potential of the enzyme adsorbed on the electrode surface, Es′, was −0.325 V vs. SCE, the semiquinone formation constant being 1.5±1.0 at pH 7.4 (25 °C). The pH dependence of Es′ was −60 mV/pH (pH 2.0–6.4), −30 mV/pH (pH 6.4–8.5), and −60 mV/pH (pH 8.5–12.0). The apparent charge transfer rate constant of the surface redox reaction was 1.6±0.5×103 s−1 at pH 5.4.
Dimeric Copper(II) Nitrato and Chloro Complexes with N-(3-Dimethylaminopropyl)salicylideneaminato Ligand Protonated at the Terminal Nitrogen
Authors: Tokii Tadashi , Tenhiro Toshihiko , Muto Yoneichiro
Published: July 2006

The title complexes have been prepared and characterized. The strong antiferromagnetic interaction observed for the complexes is interpreted in terms of a phenolic-oxygen-bridged dimeric structure with the metal ions in a square-pyramidal geometry.
The Direct Alkylamination of α-Substituted Anthraquinones Promoted by Metal Ions
Authors: Matsuoka Masaru , Takei Toshio , Nakamura Isao , Yoshida Katsuhira , Kitao Teijiro
Published: July 2006

The reaction of 1-amino-4-acylaminoanthraquinones with piperidine in the presence of CoCl2 and atmospheric oxygen gave the 2-aminated products in 75–80%, and similar reaction of 1-hydroxyanthraquinone or 1-aminoanthraquinone-2-sulfonic acid with butylamine gave the corresponding 4-aminated products, respectively. The effects of the α-substituents and the role of metal salts were discussed.
A Novel Synthesis of Phenyl Carboxylates
Authors: Hashimoto Shizunobu , Furukawa Isao
Published: July 2006

The direct synthesis of phenyl carboxylates from phenols and carboxylic acids is reported. The reactions proceeded easily when triphenylphosphine and carbon tetrachloride were used as dehydrating agents in the presence of a tertiary amine at room temperature, thus giving esters in high yields.
Studies on Biologically Active Pteridines. VI. Biopterin Conjugated to β-d-Galactosidase and Bovine Serum Albumine
Authors: Matsuura Sadao , Sugimoto Takashi , Nagatsu Toshiharu
Published: July 2006

4-Hydroxy-6-(l-erythro-1,2-dihydroxypropyl)-2-(methylthio)pteridine was converted by ethylenediamine to 2-(2-aminoethylamino)analogue of biopterin, which condensed with N-hydroxysuccimidyloxy m-maleimidobenzoate to give the maleimidobenzamide. The latter compound and β-d-galactosidase afforded a biopterin-galactosidase conjugate which showed the enzyme activity about 40% as compared to the unmodified enzyme.
A Cationic [3,4] Sigmatropic Rearrangement
Authors: Nishizawa Mugio , Noyori Ryoji
Published: July 2006

The first example of the cationic [3,4]sigmatropic reaction has been achieved by the reaction of 1,3-dibromo-3-methyl-6-hepten-2-one and diiron nonacarbonyl.
Resonance Energies of the Arenium Ions and Their Relevance to the Electrophilic Substitution Reactions
Authors: Aihara Jun-ichi
Published: July 2006

Hyperconjugative interaction through the methylene group was incorporated in the framework of the Hückel molecular orbital model. Resonance energies of the arenium ions, derived from typical benzenoid hydrocarbons, were calculated using the graph theory of aromaticity. It was found that even a benzenium ion has a considerable degree of aromaticity. In general, the arenium ion with large localization energy has both large resonance energy due to hyperconjugation and large positive charge density at the methylene group. These two quantities are possibly responsible for the competition between substitution and addition reactions on the benzenoid hydrocarbons. An aromatic transition state tends to choose a reaction path to substitution products, at least, for these compounds.
Optical Properties of Undoped and AsF5 Doped “Poly(4,4′-biphenylylene)” Films
Authors: Watanabe Atsushi , Fujimoto Hitoshi , Tanaka Masashi , Tanaka Jiro
Published: July 2006

Optical absorption and reflection measurements are carried out on undoped and AsF5 doped films of “poly(4,4′-biphenylylene)” over a wide wavelength region (300–50000 cm−1). In the doped polymer, the free carrier absorption band appears in the IR region and the dc conductivity is estimated from the observed spectrum. The obtained value (σ0=376 S cm−1) is two orders of magnitude larger than the value (σ0=2 S cm−1) observed by the conductivity measurement. The discrepancy may be due to the existence of many cracks on the films.
Proton Equilibria of a 5-Dimethylamino-1-naphthalenesulfonyl Group Conjugated to Bovine Serum Albumin. I. Effects of The Conjugation on Structural Alternation
Authors: Ikuta Nobuo , Koga Joichi , Kuroki Nobuhiko
Published: July 2006

The proton equilibria of an optical probe, the 5-dimethylamino-1-naphthalenesulfonyl group, conjugated to bovine serum albumin with various molar ratios to the protein in an acidic solution, were investigated by means of the change in the fluorescence intensity as well as that in the absorbance. Below the molar ratio of 1.7 the apparent pK values for the dimethylamino moiety of the optical probe decreased remarkably with a decrease in the pH of the solution, accompanying conformational changes of the protein caused by the proton binding to the protein. For molar ratios of more than 2.0, the alternation of the higher structure of the protein induced by the conjugation of the probe was detected by ORD measurements, while the pK values of those conjugated probes were lowered at pH’s higher than 3.0. For comparison, the probe conjugated with glycine as its free state gave the pK value of 3.99 in an aqueous solution. The shifts of the apparent pK values of the conjugated probe in the protonated protein compared with those for the free probe were, particularly, too large to arise from the Debye-Hückel electrostatic shielding effect. These results are, therefore, interpreted in terms of a change in the shortrange interaction in the neighboring residues surrounding the probe.
Ion Association of Some 2:2 Electrolytes in Water at 25 °C. III. A New Interpretation of Experimental Results and the Determination of Formation Constants of Inner-sphere Ion-pairs
Authors: Yokoyama Haruhiko , Yamatera Hideo
Published: July 2006

The results of previous studies on ion association were re-examined. The formation constants of inner-sphere ion-pairs were obtained for several bivalent-metal sulfates by estimating the formation constants of outer-sphere ion-pairs with the help of the ion-association theory. The interactions between metal and sulfate ions were discussed by comparing these results.
A Novel Cationic Optically Active Complex of Platinum(II) Containing 2-Methyl-2-butene and o-Benzenediamine. The Circular Dichroism Spectrum and Kinetics of Olefin Exchange
Authors: Miya Shin’ya , Kashiwabara Kazuo , Saito Kazuo
Published: July 2006

An optically active cationic olefin complex, [PtCl(o-benzenediamine)((S)-2-methyl-2-butene)]B(C6H5)4 was obtained for the first time as crystal stable in air at room temperature. It deteriorates slightly in solution, but is still stable enough to be characterized. Comparison of its CD spectrum with that of related complexes disclosed that the coordinating atoms at the cis sites to the olefin have a dominant influence upon the CD pattern in the region 20000–35000 cm−1, as compared with those at the trans site. Substitution of cis-1,2-dichloroethylene for the coordinated (S)-2-methyl-2-butene (S-mbn) proceeds in accordance with the second order rate law; there is no contribution of the solvent path. The second order rate constant is smaller than that of trans-[PtCl2(pyridine)(S-mbn)]. The steric effect of the o-benzenediamine at the transition state seems responsible for the small rate rather than the basicity of the ligand at the trans site to mbn.
Five-coordinate Copper(II) Complexes with a Thio Group as Type II Copper Models
Authors: Sakurai Takeshi , Suzuki Shinnichiro , Nakahara Akitsugu
Published: July 2006

Five-coordinate copper(II) complexes with a thio group were synthesized as non-blue copper(II) models by reactions of copper(II) perchlorate and condensation products of 2-pyridinecarbaldehyde or salicylaldehyde and bis(2-aminoethyl) sulfide or 2-aminoethyl 3-aminopropyl sulfide. In the complexes where thio group is coordinated to copper(II) at an equatorial position, the ESR spin Hamiltonian parameters g⁄⁄ and A⁄⁄ prominently decreased, and charge transfer bands due to sulfur to copper appeared at 300–350 nm and occasionally at 400– 500 nm. On the other hand, complexes with a thio group at an axial position afforded slightly smaller A⁄⁄ values and charge transfer bands with lower intensity in the similar regions. The biological significance of a sulfur donation to non-blue copper(II) has been discussed.
Photochemical Reactions of Aromatic Compounds. XXXVI. The Photoreactions of Anthracene with Some Selected Tertiary Aromatic Amines in Polar Media
Authors: Yasuda Masahide , Pac Chyongjin , Sakurai Hiroshi
Published: July 2006

The photoreaction of anthracene with N,N-dimethylaniline in acetonitrile gave 9-(p-dimethylaminophenyl)9,10-dihydroanthracene in a good yield, along with 9,10-dihydroanthracene and 9,9′,10,10′-tetrahydro-9,9′-bianthryl. This photoreaction was found to depend on the polarity of the solvent as well as on its protic or aprotic nature. With N,N-dimethyl-m-toluidine, a similar 1 : 1 adduct was obtained, while the reduced anthracenes were mainly formed in the photoreactions with N,N-dimethyl-o- and p-toluidines. The mechanisms were discussed in terms of the dissociation into the ion radicals as well as their reactivities.
CIDNP Studies of the Thermal Decomposition of Arylazo Aryl Sulfones
Authors: Yoshida Masato , Furuta Naoki , Kobayashi Michio
Published: July 2006

1H-and 13C-CIDNP spectra were obtained during the thermal decomposition of several arylazo aryl sulfones (Ar–N=N–SO2–Ar′) in tetrachloroethylene or 1,1,2,2-tetrachloroethane at 100 °C. An enhanced absorption from the C1 of the starting material, azo sulfone, was observed; this indicates that the decomposition of azo sulfone proceeds by means of one-bond fission. The formation of sulfones (ArSO2Ar′) and sulfinic esters (ArO(SO)Ar′) as recombination products in a solvent cage was established from the signs of polarization (enhanced absorption or emission).
Epicubebol and Related Sesquiterpenoids from the Brown Alga Dictyopteris divaricata
Authors: Suzuki Minoru , Kowata Nobuhiko , Kurosawa Etsuro
Published: July 2006

Epicubebol has been isolated from the methanol extracts of the brown alga Dictyopteris divaricata as the major constituent. Cadinane-type sesquiterpenes, cubebenes, δ-cadinene, cubenol, and epicubenol, as well as two sesquiterpene methyl ethers as minor constituents have also been obtained from the extracts.
The Pschorr Cyclization of Aromatic Amines with t-Butyl Thionitrate in Nonaqueous Media
Authors: Oae Shigeru , Iida Kazuyuki , Shinhama K\={o}ichi , Takata Toshikazu
Published: July 2006

The Pschorr cyclization of various arylamines with t-butyl thionitrate under nonaqueous conditions gave the, corresponding cyclic products in moderate yields. The same reaction was also found to proceed readily with p-toluenesulfonyl nitrite at room temperature. Treatment of o-aminophenyl allyl ether or sulfide with t-butyl thionitrate resulted in the intramolecular Meerwein arylation to the olefinic bond affording 3-chlorochroman or -thiochroman, though the yield was low. The plausible mechanism of the Pschorr cyclization with t-butyl thionitrate is discussed.
Branched-chain Sugars. XXIV. Synthesis of Methyl 6-Deoxy-3-C-methyl-β-d-gulopyranoside (Methyl β-Virenoside)
Authors: Hong Namgi , Sato Ken-ichi , Yoshimura Juji
Published: July 2006

Methyl 6-deoxy-3-C-methyl-β-d-gulopyranoside (methyl β-virenoside) was prepared from d-galactose. An attempted synthesis of the virenoside by the inversion at C-4 of methyl 6-deoxy-3-C-methyl-α-d-allopyranoside was unsuccessful.
The Reaction of 2,4,6-Triphenyl-1,3-oxazinylium Perchlorate with Amino Compounds
Authors: Shibuya Isao
Published: July 2006

The reaction of 2,4,6-triphenyl-1,3-oxazinylium perchlorate with various kinds of amino compounds was studied. Primary amines and semicarbazides gave pyrimidinium perchlorates. o-Phenylenediamine, o-aminobenzamide, and o-aminothiophenol afforded 2,4-diphenyl-1,5-benzodiazepine, 2-phenyl-4-hydroxyquinazoline, and 2-phenyl-1,3-benzothiazole respectively. Benzoylhydrazine, 4-pyridinecarbohydrazide, and 4-phenylthiosemicarbazide all led to pyrazoline derivatives. N,N-Dimethylhydrazine yielded two chain products competitively, while N,N′-dimethylhydrazine gave 1,2-dimethyl-3,5-diphenyl-1,2,4-triazolylium and 1,2-dimethyl-3,5-diphenylpyrazolylium perchlorate competitively. It was thus shown that 2,4,6-triphenyl-1,3-oxazinylium perchlorate reacts with amino compounds in a complicated fashion to afford various heterocyclic compounds and other derivatives.
The Determination of the Chemical Diffusion Coefficient of n-Type AgBr by Means of a D.c. Polarization Cell
Authors: Sasaki Jun , Mizusaki Junichiro , Yamauchi Shigeru , Fueki Kazuo
Published: July 2006

The electronic conductivity of AgBr and the chemical diffusion coefficient of n-type AgBr were measured by means of a d.c. polarization cell, \ominus Ag/AgBr/inert electrode ⊕, in the temperature range from 325 °C to 400 °C. In order to suppress the electrolysis of AgBr, a platinum plate was used instead of carbon as the inert anode. The chemical diffusion coefficient, \ ildeD, was determined by two methods. One was the intermediate probe method (IP method) whereby the relaxation of the voltage between the Ag reversible electrode and the Pt intermediate probe, inserted into the middle of AgBr, was followed after an abrupt change in the polarization voltage. The other was the open-circuit method (OC method) whereby the terminal voltage of the cell was followed after the circuit of the cell had been opened. The electronic conductivity in the steady state was independent of the nature of the inert electrodes (Pt or C), provided that the inert electrode was completely sealed. However, it took more time for the cell with a carbon electrode to reach the steady state than that with a platinum one. The chemical diffusion coefficient, \ ildeD, determined by the IP method for the Ag/AgBr/Pt cell agreed with that for the Ag/AgBr/C cell. The chemical diffusion coefficient, \ ildeD, determined by the OC method for the Ag/AgBr/Pt cell agreed with that obtained by the IP method. The chemical diffusion coefficients determined by these methods were expressed by

\ ildeD=3.0×103exp\left(\frac−89.9 kJ mol−1RT\ight)⁄cm2 s−1.

No chemical diffusion coefficient can be obtained by the OC method for the Ag/AgBr/C cell, because of the slow diffusion of the Br2 gas produced by the electrolysis of AgBr from the carbon electrode.
Applications of Homogeneous Water-gas-shift Reaction. I. Further Studies of the Hydroformylation of Propene with CO and H2O
Authors: Murata Kazuhisa , Matsuda Akio
Published: July 2006

Polar ether solutions prepared in situ from Co2(CO)8 and 1,2-bis(diphenylphosphino)ethane (diphos) are active catalysts for the hydroformylation of propene with CO and H2O. Under the hydroformylation conditions employed, butyl (C4) or isobutyl alcohols, butyric (C4) acids, and dipropyl ketones were found to be formed as by-products. A pronounced formation of C4 alcohols was observed as the reaction temperature was increased; in fact, the catalyst solutions described above actively reduce butyraldehyde to butyl alcohol. The effects of the CO pressure and of the propene concentration on the formation of C4 aldehydes are also examined. It turns out that the water molecule as well as Co2(CO)8 and diphos are essential for the formation of catalytic intermediates, which are themselves responsible for the hydroformylation activity.
An Electron Spin Resonance Study of the Phosphorescent Triplet State of Poly(vinylnaphthalene)s
Authors: Higuchi Jiro , Yagi Mikio , Saito Juichiro , Takanashi Midori
Published: July 2006

The electron spin resonance (ESR) of poly(1-vinylnaphthalene) and poly(2-vinylnaphthalene) in their phosphorescent triplet states is studied in glassy solutions and in plastic hosts. The zero-field splitting parameters thus obtained are discussed in comparison with those of 1- and 2-methylnaphthalene. Through the ESR measurement, the possibility of detecting the triplet energy transfer through the naphthyl groups is examined.
Electrode Kinetics of the Redox Couples of Co(III/II) Complexes with Ethylenediamine-N-acetate, Iminodiacetate, and Diethylenetriamine
Authors: Ohsaka Takeo , Oyama Noboru , Yamaguchi Shuichiro , Matsuda Hiroaki
Published: July 2006

The electrochemical kinetic parameters of Co(edma)21+⁄0 (edma: ethylenediamine-N-acetate), Co(ida)21−⁄2− iminodiacetate), Co(dien)23+⁄2+ (dien: diethylenetriamine), Co(1,2-pn)33+⁄2+ (1,2-pn: 1,2-propanediamine), and Co(gly)30⁄1− (gly: glycinate) redox couples were determined by d.c. and normal pulse polarographic measurements as well as galvanostatic double pulse measurements. A difference in the evaluated kinetic parameters for the geometric isomers, trans(O)- and cis(O)-Co(edma)21+⁄0 and trans(N)- and cis(N)-Co(ida)21−⁄2− couples, was recognized. The values of the standard rate constant for the bis forms with dien, edma, and ida were reduced with increase in the number of replacement of amino groups in dien by carboxyl groups. The standard rate constants of the redox couples of Co(III/II) complexes with a series of bi- and tridentate polyamines and aminocarboxylates increase in proportion to the number of nitrogen donor atoms involved in the ligands.
Formation of Micelles of Acylcarnitines in Glycerol
Authors: Ionescu Lavinel G , Fung Daniel S
Published: July 2006

Acylcarnitine chlorides form micelles in water and polyprotic solvents such as glycerol, ethylene glycol; 1,3-propanediol and 1,4-butanediol. The effect of the acyl chain on the formation of micelles was studied for compounds with chain lengths of 2 to 16 carbon atoms. The critical micellar concentration in glycerol was determined at 25 °C by means of difference spectroscopy using phenol as a probe. The acylcarnitine chlorides with chains containing less than 8 C atoms do not form micelles in glycerol. The critical micellar concentration varies from 0.060 mol dm−3 for octanoylcarnitine to 0.011 mol dm−3 for palmitoylcarnitine. The free energy of micellization, ΔGmic°, varies linearly with chain length in the range of −6.95 kJ mol−1 to −11.2 kJ mol−1. The “hydrophobic” or “solvophobic” effect was more pronounced in water than in glycerol and the free energy change per metylene group was −2.89 kJ mol−1 and −0.75 kJ mol−1, respectively. The formation of micelles of acylcarnitine chlorides in glycerol is important in terms of the metabolism of fatty acids and their transport across biological membranes.
Peroxomonophosphoric Acid Oxidations. VI. Kinetics and Mechanism of Oxidation of 3-Aminopyridine
Authors: Mahapatro Surendra Nath , Panda Abhina Kumar , Panigrahi Ganesh Prasad
Published: July 2006

The oxidation of 3-aminopyridine to 3,3′-azoxypyridine by peroxomonophosphoric acid (PMPA) is a total second order reaction: first order each in peroxomonophosphoric acid and 3-aminopyridine at constant acidity. The observed pH-rate profile has been rationalized invoking various PMPA species, protonated and unprotonated forms of 3-aminopyridine as the reactive species and their reactivities have been estimated. Interestingly, 2-aminopyridine is not oxidized in the pH-range where the oxidation of 3-aminopyridine is facile.
The Crystal and Molecular Structure of 2-Acetoxy-2-methyl[1,3]dioxolo[4,5-c]isoquinoline-5-carbonitrile. A Photoproduct of 1,4-Diacetoxy-2,3-diazidonaphthalene
Authors: Kitano Yukishige , Ashida Tamaichi , Yabe Akira
Published: July 2006

The crystal of the title compound is triclinic, with a space group of P\bar1 and with two molecules per unit cell with dimensions of a=8.317 (2), b=11.191 (1), c=7.731 (1)Å, α=105.91 (1), β=103.76 (2), and γ=102.60 (1)°. The fused isoquinoline and dioxolane rings lie on nearly the same plane; the non-hydrogen atoms of the acetoxyl and methyl groups make another plane. These two planes make an angle of 92.0° with each other.
On the Additivity of Molar Volume and Refractivity of Molten Ca(NO3)2·3.18H2O–KSCN System
Authors: Mahiuddin Sheik , Ismail Kochi
Published: July 2006

Densities and refractive indices of Ca(NO3)2·3.18H2O-KSCN melts have been measured as functions of temperature and composition. Densities, molar volumes, and refractive indices show linear dependence on temperature. Molar volume, intrinsic volume, molar refractivity, and the product of refractive index and molar volume show additivity within ±2% error. The molten Ca(NO3)2·3.18H2O–KSCN system at ambient temperatures appears to behave like an ideal mixture of molten Ca(NO3)2·3.18H2O and supercooled KSCN melt.
A New Synthetic Route to Electrophilic Cyclopropane Derivatives from Olefins
Authors: Kawabata Nariyoshi , Yano Shinji , Hashimoto Jiro , Yoshida Jun-ichi
Published: July 2006

1,1-Bis(alkoxycarbonyl)-, 1-alkoxycarbonyl-1-cyano-, and 1,1-dicyanocyclopropane derivatives were obtained in 10–99% yields by the reaction of Br2C(COOR)2, Br2C(CN)(COOR), and KBr[Br2C(CN)2]4, respectively, with olefins and Cu2Br2 in dimethyl sulfoxide (DMSO).
Facile Intramolecular Cyclization Reactions of Aromatic Ethers with Cationoids in Triptycene Systems
Authors: Izumi Giichi , Hatakeyama Shiro , Nakamura Nobuo , Oki Michinori
Published: July 2006

1,4-Dimethoxytriptycenes were found to give cyclic ethers with unusual ease when a substituent at the bridgehead bears a cationoid center. The easy reaction is attributed to the extreme proximity between the methoxyl group and the cationic center. Mechanisms involving a cyclic oxonium ion and subsequent attack by an anion to produce the cyclic ether and a methyl derivative are discussed.