bluuebunny/crossref_metadata_2025 huggingface dataset:
Specific Binding of Substrates Containing Nitrogen and Oxygen Donor Groups to Copper(II)–Gadolinium(III) Hetero-Metal Center
Authors: Sakamoto Masatomi , Ishimori Tomitaro , Okawa Hisashi
Published: July 2006

Substrate binding to the Cu(II)–Gd(III) heterometal complex of N,N′-bis(3-carboxysalicylidene)ethylenediamine was studied in N,N-dimethylformamide. It was suggested that substrates with a nitrogenous and an oxygenous groups (amino alcohols, 8-quinolinol, amino acids, and amino acid esters) were specifically bound to the Cu(II)–Gd(III) center, with the nitrogen to the copper and with the oxygen to the gadolinium.
Relationship between Solubility and Micellization of Surfactants; Micelle Temperature Range (MTR) Instead of Krafft Point
Authors: Moroi Yoshikiyo , Matuura Ryohei
Published: July 2006

In order to clarify the relation between the solubility and micellization of surfactants, the micellar temperature range (MTR) is proposed instead of the usually used Krafft point. The physicochemical meaning of cmc defined by Phillips was examined from a mathematical point of view. As a result, it became clear that the temperature range for MTR is based on the concentration range for cmc, which in turn results from the polydispersity of micelles. The mass-action model of multiple association can be used to explain these facts. The MTR, thus determined by solubility and by cmc, was found to be able to explain a leveling of the MTR for homologous surfactants with an increase of the alkyl chain length and its increase of sodium dodecyl sulfate with increasing concentration of added sodium chloride.
Phosphorescence Properties of Pyridine and Its Methyl Derivatives in the Vapor Phase
Authors: Suzuki Masayuki , Fujita Masahisa , Takemura Takeshi , Baba Hiroaki
Published: July 2006

The phosphorescence spectra, lifetimes, and quantum yields of pyridine and its methyl derivatives, 2-picoline, 3-picoline, and 2,6-lutidine in the vapor phase have been measured with the aid of a specially designed circuit by means of control of the voltage imposed on the photomultiplier. The phosphorescence spectrum shifts to shorter wavelengths with increasing methylation. The phosphorescence lifetimes and quantum yields of pyridine and the picolines are of the order of 1 μs and 10−7 both values being one order of magnitude smaller than the corresponding values for the lutidine. These observations are explained by assuming that (1) the lowest triplet state (T1) and the next lowest triplet (T2) are of 3(π,π*) and 3(n,π*) types respectively, (2) the energy gap between T1 and T2 is small, especially in the unsubstituted pyridine, and (3) the potential energy curve for T1 is distorted according to the energy gap, as the result of a pseudo-Jahn-Teller type of interaction between T1 and T2.
The Contents and Distributions of Arsenic, Antimony, and Mercury in Geothermal Waters
Authors: Sakamoto Hayao , Kamada Masaakira , Yonehara Norinobu
Published: July 2006

The contents and distributions of arsenic, antimony, and mercury in geothermal water samples taken from various geothermal areas in Japan were investigated. Since the existing forms of arsenic, antimony, and mercury in geothermal waters are complex and can change during sample storage, it is difficult to determine all of the chemical forms. In this study, therefore, the arsenic(III+V), antimony(III+V), and total mercury contents were determined. In geothermal water, there is a high positive correlation between the contents of arsenic and antimony. However, there is no correlation at all between the contents of mercury and arsenic, or between those of mercury and antimony. It can be assumed that mercury behaves differently from either arsenic or antimony in geothermal water.
Synthesis of Skeleton of Antitumor Quassinoid
Authors: Sasaki Makoto , Murae Tatsushi , Matsuo Hisaaki , Konosu Toshiyuki , Tanaka Naoko , Yagi Kiyoshi , Usuki Yoshinosuke , Takahashi Takeyoshi
Published: July 2006

A compound having a skeleton of an antitumor quassinoid, bruceantin, was prepared according to the following strategy; 1) construction of ring ABC from ring AB by cyclization of a hindered 1,5-diketone; 2) construction of ring E (ether ring) by opening of a 12,13-epoxide ring followed by attack of oxygen at C-20 toward C-13; 3) formation of ring D (hemiacetal ring) by treatment of a 7α-hydroxy-16-al dimethyl acetal with PPTS.
Reactions of (Triphenylphosphine)gold(I) Enolates and Homoenolates
Authors: Murakami Masahiro , Inouye Masahiko , Suginome Michinori , Ito Yoshihiko
Published: July 2006

Some reactions of (triphenylphosphine)gold(I) enolates and homoenolates, which are respectively prepared by the reaction of trimethylsilyl ethers of enols and cyclopropanols with (triphenylphosphine)gold(I) chloride in the presence of cesium fluoride, are described. The aldol reaction of (triphenylphosphine)gold(I) enolates with carbonyl compounds is efficiently promoted by Lewis acids such as titanium tetrachloride and diethylaluminum chloride to produce β-hydroxy carbonyl compounds. (Triphenylphosphine)gold(I) enolate reacts with phenyl acetylene to afford (triphenylphosphine)gold(I) phenylacetylide in good yield. Reaction of (benzoylmethyl)(triphenylphosphine)gold(I) (3a) with chlorotrimethylsilane produces α-(trimethylsilyloxy)styrene and (triphenylphosphine)gold(I) chloride, which is the reverse of the formation of 3a. Gold(I) enolate undergoes an isocyanide insertion reaction into the linkage of carbon and gold. (2-Benzoylethyl)(triphenylphosphine)gold(I) reacts with 2-methyl-2-propanethiol to afford (triphenylphosphine)gold(I) t-butyl sulfide together with propiophenone.
Preparation and Characterization of Large Surface Area BaO·6Al2O3
Authors: Machida Masato , Eguchi Koichi , Arai Hiromichi
Published: July 2006

Barium hexaaluminate, BaO·6Al2O3, exhibited excellent heat resistance in maintaining a large surface area. Preparation from hydrolysis of metal alkoxides was a superior process in deriving the large surface area of BaO·6Al2O3, to that from mixtures of BaCO3⁄γ-Al2O3. Direct formation of BaO·6Al2O3 phase at low temperature plays the key role in retaining the fine particle size. The amount of water added for hydrolysis and the aging period of hydrolyzed precursors strongly influenced the surface area of alkoxide-derived BaO·6Al2O3. These effects of the preparation conditions originated from the difference in microstructure and chemical structure of the hydrolyzed precursors. Monodispersed fine precursor particles with high oxide content generated large surface area BaO·6Al2O3.
Organophosphorus Analogues and Derivatives of the Natural l-Amino Carboxylic Acids and Peptides. III. Synthesis and Enzyme-Substrate Interactions of d-, Dl-, and l-5-Dihydroxyphosphinyl-3,4-didehydronorvaline and Their Cyclic Analogues and Derivatives
Authors: Natchev Ivan A
Published: July 2006

The unusual natural amino acid phosphorus containing didehydronorvaline (5) has been synthesized by consecutive treatment of the 4-bromo-2-butenal (1) with potassium cyanide and ammonium carbonate to the hydantoin (2), converted into the organophosphorus derivative 3, followed by enzyme-catalyzed hydrolysis of the diethoxyphosphinyl group to the phosphonic acid 4, and hydrolysis. The tetrahydro-1,2-azaphosphorine (8) and the protected didehydronorvaline derivatives 6, 7, 9, and 10, have been synthesized.
Organic Derivatives of Layered Polysilicates. II. Reaction of Magadiite and Kenyaite with Diphenylmethylchlorosilane
Authors: Yanagisawa Tsuneo , Kuroda Kazuyuki , Kato Chuzo
Published: July 2006

Silanol groups on the interlayer surface of layered polysilicic acids (H-magadiite and H-kenyaite) were silylated by reaction with diphenylmethylchlorosilane. Dodecyltrimethylammonium magadiite and kenyaite intercalation compounds were used as the intermediates for the conversion. The interlayer modification was confirmed by XRD, IR, 29Si-MAS NMR and elemental analysis.
Synthesis of 2-Aryl[1,2,4]triazolo[1,5-a]pyrimidines
Authors: Kamala K , Jayaprasad Rao P , Kondal Reddy K
Published: July 2006

2-(Aroylamino)pyrimidines (4) have been converted into 1-(2-pyrimidyl)-5-aryl-1H-tetrazoles (6) by treatment with PCl5 followed by azidolysis in aqueous acetone solution. Pyrolysis of 6 in decalin gave 2-aryl[1,2,4]triazolo[1,5-a]pyrimidines (8). A reasonable pathway for the formation of 8 from 6 is suggested. Structures of all the compounds have been established by elemental analysis and spectral data.
Synthesis of the Cyclohexylammonium Form of α-Zirconium Phosphate and Its Application to Nickel(II) Ion Exchange
Authors: Hasegawa Yoshitsugu , Sasaki Kaname , Tanaka Hiroe
Published: July 2006

The uptake of cyclohexylamine with α-zirconium phosphate was studied by means of the pH-titration method. Cyclohexylamine was loaded up to 75% of the ion-exchange capacity of α-zirconium phosphate. Chemical analysis, thermal analysis, infrared spectroscopy, and X-ray diffractometry were used to characterize the product obtained at the final step of pH titration, which was referred to as the cyclohexylammonium form. The chemical composition can be presented as Zr(C6H11NH3)1.5(H)0.5(PO4)2·H2O. The interlayer distance of the exchanger expanded to 18.4 Å upon the uptake of cyclohexylamine. The cyclohexylammonium ion was exchanged easily with the nickel(II) ion in a solution.
Metal-Catalyzed Organic Photoreactions. Titanium(IV) Chloride-Catalyzed Photoreactions of Aldohexoses
Authors: Ichikawa Shuji , Takahashi Kazuo , Tanaka Masato , Sato Tadashi
Published: July 2006

Under UV irradiation in the presence of titanium(IV) chloride in methanol, d-glucose, d-mannose, and d-galactose underwent a selective bond cleavage at the C5–C6 position, producing the corresponding pentodialdose derivatives. The reaction was interpreted in terms of the photoinduced electron transfer within a chelate of titanium ion with the carbohydrate molecule. The synthetic utilities of the photoproducts were discussed.
Crystal Structure and Molecular Structure of Neutral Nickel Bis(5,6-dihydro-1,4-dithiin-2,3-dithiolate), Ni(dddt)2
Authors: Kim Hyernjoo , Kobayashi Akiko , Sasaki Yukiyoshi , Kato Reizo , Kobayashi Hayao
Published: July 2006

Neutral species of multi-sulfur 1,2-dithiolene complex, Ni(dddt)2 (dddt=5,6-dihydro-1,4-dithiin-2,3-dithiolate), was synthesized and the crystal structure has been determined. Crystals are monoclinic, space group P21⁄c, with Z=4, a=18.350(10), b=4.672(1), c=20.326(12) Å, β=125.56(3)°, V=1417(1) Å3. The structure was solved by the Patterson method, and refined by a block-diagonal least-squares method to R=0.081 for 1316 unique reflections. Two independent molecules of Ni(dddt)2 are stacked along the b-axis separately, with interplanar distances of 3.76 Å and 3.74 Å, respectively.
Electroreduction of Phenylhydrazones in Methanol–Water Mixtures
Authors: Kameswara Rao Vepa , Venkatachalam Chitoor Sivaramakrishnan , Kalidas Chatty
Published: July 2006

The electroreduction of a few substituted phenylhydrazones on mercury cathode has been studied in methanol–water mixtures using polarography, cyclic voltammetry, micro- and macrocontrolled-potential electrolysis. These compounds are reduced in a single four-electron step to yield the corresponding amino products. A linear relationship between the half-wave potentials (E1⁄2) and Hammett substituent constants (σ) has been observed.
An X-Ray Diffraction Study on the Structures of Monochloropentakis(N,N-dimethylformamide)copper(II), Trichloromono(N,N-dimethylformamide) and Tetrachlorocuprate(II) Complexes in N,N-Dimethylformamide
Authors: Ozutsumi Kazuhiko , Ishiguro Shin-ichi , Ohtaki Hitoshi
Published: July 2006

The structure of the monochlorocopper(II), trichloro- and tetrachlorocuprate(II) complexes in N,N-dimethylformamide (DMF) has been studied by the X-ray diffraction method at 25 °C. The radial distribution curve obtained for a solution containing the monochlorocopper(II) complex as the predominant species reveals the presence of an axially elongated octahedral [CuCl(dmf)5]+ complex, three Cu–O(eq) and two Cu–O(ax) bond lengths being 199(1) and 239(4) pm, respectively. The chloride ion binds to the copper(II) ion at the equatorial site and the Cu–Cl distance is 220(2) pm. The Cu–O(eq) bond length within the [CuCl(dmf)5]+ complex is practically the same as that within the [Cu(dmf)6]2+ (203 pm). The X-ray scattering data of solutions containing the tri- and tetrachlorocuprate(II) complexes as the main species are well explained in terms of the existence of the distorted tetrahedral [CuCl3(dmf)]− and [CuCl4]2− complexes, respectively, in the solutions. The Cu–Cl and Cu–O bond lengths within the [CuCl3(dmf)]− complex are 219(1) and 230(13) pm, respectively. The Cu–O distance within the complex is longer than that of the equatorial Cu–O bond within the [Cu(dmf)6]2+ and [CuCl(dmf)5]+ ions. The Cu–Cl bond length within the [CuCl4]2− complex is 226(1) pm and is longer than that within the [CuCl3(dmf)]2− complex. The nonbonding Cl···Cl distances within the [CuCl4]2− complex are 346(3) and 412(6) pm.
The Conversion of (+)-Dehydroabietic Acid into Steroidal Hormones
Authors: Matsumoto Takashi , Imai Sachihiko , Sunaoka Yasuhiro , Yoshinari Takashi
Published: July 2006

A resin acid, (+)-dehydroabietic acid, was converted into 3,4,4a,9,10,10a-hexahydro-7-methoxy-10aβ-methyl-4aαH-phenanthren-1(2H)-one (2) by the introduction of oxygen functions at the C-4 and C-13 positions, and a rearrangement of the angular methyl group to the C-5 position. The hydrophenanthrene derivative 2 was further transformed into 2,3,3a,4,5,9b-hexahydro-7-methoxy-3aβ-methyl-9bαH-1H-benz[e]inden-3β-ol (3). Since the conversion of 3 into steroidal hormones has already been reported, the present synthesis can be regarded as the synthesis of steroidal hormones from (+)-dehydroabietic acid.
Reactions of Coordination Compounds in the Solid State. III. The Behavior of the Isomers of Dichloro(triethylenetetramine)cobalt(III) Bromide and Iodide, [Co(trien)Cl2]X
Authors: Fujiwara Terufumi , Bailar John C
Published: July 2006

The rearrangement of the isomers of dichloro(triethylenetetramine)cobalt(III) bromide and iodide upon heating in the solid state has been studied in relation to the corresponding isomers of the chloride. The behavior of the bromide and iodide has been found to be different from that of the chloride, supporting the existence of anion effects in the solid-state reactions. With respect to the nature of the anions, several factors which are responsible for the differences are discussed in relation to mechanism.
The Oxidation of Some Naphthols with Benzoyl Peroxide
Authors: Matsumoto Takashi , Imai Sachihiko , Yamamoto Naoya
Published: July 2006

The reactions of four naphthols (1-naphthol (1), 2-naphthol (2), 4-isopropyl-1-naphthol (18), and 3-isopropyl-2-naphthol (19)) with benzoyl peroxide were examined under two reaction conditions (A and B). Each of the naphthols 1, 2, 18, and 19 was oxidized with 0.95 equivalent moles of benzoyl peroxide at room temperature for 24 h (condition A) to give mainly the corresponding ortho-benzoyloxylated product which was isolated in moderate yield as an equilibrium mixture, resulting from its trans -benzoylation. The naphthols 18 and 19 were also oxidized with 2.25 equivalent moles of benzoyl peroxide at room temperature for 48 h (condition B) to give mainly 2,2-bis(benzoyloxy)-4-isopropyl-1(2H)-naphthalenone and 2,2-bis(benzoyloxy)-3-isopropyl-1(2H)-naphthalenone in good yields. The oxidations of 1 and 2 under condition B produced the same product, 2,2-bis(benzoyloxy)-1(2H)-naphthalenone, in low yields.
Chiral Synthesis via Organoboranes. 11. Hydroboration. 82. Asymmetric Hydroboration of 1-Heteroarylcycloalkenes with Monoisopinocampheylborane. Synthesis of trans-2-Heteroarylcycloalkyl Boronates and Derived Alcohols of Very High Enantiomeric Purity
Authors: Brown Herbert C , Gupta Ashok K , Vara Prasad J V N
Published: July 2006

The hydroboration of representative 1-heteroarylcycloalkenes with monoisopinocampheylborane (IpcBH2) was investigated systematically to establish the degree of asymmetric induction during hydroboration. The hydroboration of 1-heteroarylcyclopentene with IpcBH2 at −25 °C proceeded cleanly to afford the corresponding dialkylboranes. These dialkylboranes, upon treatment with acetaldehyde and then oxidation, afforded the corresponding trans-2-heteroarylcycloalkanols of 85–86% ee. Similarly, 1-heteroarylcyclohexenes, upon hydroboration with IpcBH2, followed by acetaldehyde treatment and oxidation, gave the corresponding alcohols in ca. 90% ee. The dialkylboranes or alkylboronic acids derived from 1-heteroarylcyclopentenes and IpcBH2 can be recrystallized to furnish materials approaching 100% ee. From such dialkylboranes or alkylboronic acids, the corresponding boronates of ca. 100% ee were prepared and isolated. These are proving to be highly versatile synthetic intermediates for organic synthesis.
Adsorption of Xenon in the Zeolitic Pore in the Henry’s Law Region of the Isotherms
Authors: Yoshida Toshihisa , Koizumi Jun-ichi , Akai Yoshio
Published: July 2006

The isotherms and the 129Xe NMR spectra of Xe adsorbed on HY and USY zeolites of faujasite structure were measured. There were two kinds of Xe species, which could be distinguished as one trapped on the internal surface of the supercage and the other freely mobile in the supercage.
Oxidation of 2,4-Di-t-butylphenol with Hydrogen Peroxide Catalyzed by Bis(ethylenediamine)copper(II) Complexes
Authors: Kushioka Keiko , Tanimoto Iwao , Maruyama Kazuhiro
Published: July 2006

2,4-Di-t-butylphenol (1) was efficiently oxidized with H2O2 in methanol in the presence of bis(ethylenediamine)copper(II) (Cu(II)(en)2) complexes. Activity of the Cu(II) complexes was strongly dependent on the structure of the en ligands, as in the cases of the O2 oxidation of phenol 1. In the H2O2 oxidation of 1, ens having none of N-alkyl substituent were of the most efficient. By addition of H2O2, stable Cu(II)(en)2 complexes exhibited a new absorption at 340 nm, which was assigned to Cu(II)–en–H2O2 (1:2:1) complexes. Furthermore, the rapid-scanning spectrophotometry proved that quadruple Cu(II)–en–phenol 1–H2O2 (1:1:1:1) complexes were the key intermediate for the oxidation of 1. The initial velocity can be summarized in the equation v=k[H2O2]1[phenol 1]1[Cu(II)(en)2]1. The oxidation mechanism of phenol 1 with H2O2 is proposed.
Magnesium Ion Assisted Highly Regio- and Chemoselective Reduction of 5H-Pyrrolo[3,4-b]pyridine-5,7(6H)-diones with Sodium Borohydride. A Convenient Synthesis of 6,7-Dihydro-7-hydroxy-5H-pyrrolo[3,4-b]pyridin-5-ones
Authors: Goto Takehiko , Konno Michio , Saito Minoru , Sato Ryu
Published: July 2006

6-Substituted and unsubstituted 6,7-dihydro-7-hydroxy-5H-pyrrolo[3,4-b]pyridin-5-ones were predominantly obtained in excellent yield by the reduction of the corresponding 5,7-diones with sodium borohydride in the presence of Mg ion at 0 °C. The highly regioselective production of the 7-hydroxy lactam in preference to the 5-hydroxy isomer was reasonably interpreted in terms of a chelate complex formation between the dione and Mg ion. The regioisomeric assignment was achieved by the transformation of the 7-hydroxy lactam to 2-(hydroxymethyl)-3-pyridinecarboxamides which could be converted to the known azaphthalide, furo[3,4-b]pyridin-5(7H)-one. Furthermore, the high chemoselectivity was found to be retained below 0 °C to give the partial reduction product, hydroxy lactam, exclusively.
Vanadium Oxides (V2Ox) Catalysts for Dry-Type and Simultaneous Removal of Sulfur Oxides and Nitrogen Oxides with Ammonia at Low Temperature
Authors: Kasaoka Shigeaki , Sasaoka Eiji , Iwasaki Hideto
Published: July 2006

In order to develop highly functional catalysts for a dry-type, simultaneous removal of sulfur oxides (SOx) and nitrogen oxides (NOx) the catalytic activities of V2Ox/TiO2, V2Ox/TiO2/AC(activated carbon) and V2Ox/AC (4<x<5) were studied using a fixed bed flow reactor. In this process SO2 is catalytically oxidized to SO3 and then fixed on the catalyst as ammonium sulfates by reactions with H2O and NH3; NOx are reduced to N2 with NH3 over the same catalyst at low temperature (ca. 130 °C). The sulfates deposited on the catalyst must be periodically removed for regeneration in order to realize repeated use of the catalyst. V2Ox/TiO2 was found to be a suitable catalyst for the simultaneous removal and to have an acceptable tolerance for reiterative regeneration. Also, water washing of the used catalyst after a NH3 pretreatment was found to be preferable for regeneration. The sulfates deposited on the catalyst could be recovered as (NH4)2SO4 by this type regeneration. The deposited sulfates were amorphous and could be regarded as being a mixture of NH4HSO4 and (NH4)2SO4. These sulfates reacted with NOx to produce N2.
Inhibiting Effects of Ethanethiol, Dimethyl Sulfide, and Dimethyl Disulfide on the Corrosion of Stainless Steel (405) in Sulfuric Acid
Authors: Saleh Jalal Mohammed , Al-Haidari Yousif Kadim
Published: July 2006

The corrosion behavior of stainless steel (405) specimen in 5 M H2SO4 solution has been investigated potentiostatically at four temperatures in the range 303–323 K. The inhibiting effects of ethanethiol (EtSH), dimethyl sulfide (Me2S), and dimethyl disulfide (Me2S2) have thereafter been tested for four inhibitor concentrations of 0.5, 1, 5, and 10 mmol dm−3. The sulfur compound addition to the H2SO4 solution caused a shift, mainly in the cathodic direction, of the corrosion potential, the electrode potential at low current densities as well as of the linear section of the cathodic Tafel line. The protection efficiency of each sulfur compound was determined at various temperatures and inhibitor concentrations. The sulfur compound acted as a corrosion inhibitor in the H2SO4 solution through adsorption on the stainless steel surface. The kinetic results, operating through a compensation effect, could well account for the variation of the inhibiting capacities of the various sulfur compounds. The results indicated that inhibition process involved the shift of the stainless steel corrosion to those surface sites which are associated with progressively higher energy of activation. EtSH was the most efficient of the three sulfur compounds for inhibiting the corrosion of the stainless steel in H2SO4 solution.
Triethylborane-Induced Hydrodehalogenation of Organic Halides by Tin Hydrides
Authors: Miura Katsukiyo , Ichinose Yoshifumi , Nozaki Kyoko , Fugami Keigo , Oshima Koichiro , Utimoto Kiitiro
Published: July 2006

The reduction of organic halides with tributyltin hydride in the presence of a catalytic amount of triethylborane has been studied. (1) Alkyl iodides and alkyl bromides reacted easily with tin hydride at −78°C to give the corresponding hydrocarbons, while alkyl chlorides were sluggish to react and recovered unchanged. (2) The reduction of alkenyl halides such as 1-deuterio-1-iodo-1-dodecene and 1-iodo-1-triethylsilyl-1-dodecene proceeded nonstereospecifically. (3) The reduction of aryl halides with n-Bu3SnH–Et3B system was not so effective as the reduction of alkyl halides and alkenyl halides. Whereas aryl iodides were reduced at room temperature with n-Bu3SnH, aryl bromides hardly reacted with n-Bu3SnH even at 80 °C.
Novel Electron Acceptors Bearing a Heteroquinonoid System. I. Synthesis and Conductive Complexes of 5,5′-Bis(dicyanomethylene)-5,5′-dihydro-Δ2,2′-bithiophene and Related Compounds
Authors: Yui Koji , Aso Yoshio , Otsubo Tetsuo , Ogura Fumio
Published: July 2006

Novel electron acceptors bearing a heteroquinonoid system, 5,5′-bis(dicyanomethylene)-5,5′-dihydro-Δ2,2′-bithiophene, its 3,3′-dichloro, 3,3′-dibromo, and 3,3′,4,4′-tetrabromo derivatives, and 5,5″-bis(dicyanomethylene)5,5″-dihydro-Δ2,2′:5′,2″-terthiophene were synthesized by the action of tetracyanoethylene oxide or by Pd(0)-catalyzed substitution reactions with sodium dicyanomethanide on the corresponding α,α′-dihalogenoheteroaromatics. They showed very small on-site Coulomb repulsion as expected, and afforded several highly conductive molecular complexes with electron donors such as hexamethylenetetratellurafulvalene.
Strongly Deformed TCNQ Derivatives: Syntheses and Properties of 7,12-Bis(dicyanomethylene)-7,12-dihydrobenz[a]anthracene (BDCNBA) Derivatives
Authors: Maruyama Kazuhiro , Imahori Hiroshi , Nakagawa Katsuhiko , Tanaka Nobuo
Published: July 2006

In spite of large steric repulsion between aromatic quinone moiety and dicyanomethylene moiety the title compounds (BDCNBA) were synthesized by TiCl4-catalyzed reactions of the corresponding aromatic quinones and malononitrile. BDCNBA showed electronic spectra indicating the intramolecular charge-transfer interaction and redox properties similar to 11,11,12,12-tetracyano-9,10-anthraquinodimethane (TCNAQ) derivatives. BDCNBA showed a low electrical conductivity (≈10−7 Ω−1 cm−1). Strongly deformed structure of BDCNBA was established by X-ray crystallographic analysis.
Revised Structures, Benz[cd]indol-2(1H)-ones, for the Ring-Contracted Cycloadducts from 1-Substituted Cyclohepta[b]pyrrol-2(1H)-ones with Acetylenes
Authors: Mori Akira , Tian Guan Rong , Takeshita Hitoshi , Takehiro Toshiyuki , Abe Noritaka
Published: July 2006

Formerly-proposed structures, cyclopent[de]isoquinolin-3(4H)-ones, for ring contracted by-products obtained from 1-substituted cyclohepta[b]pyrrol-2(1H)-ones and acetylenes, were revised to benz[cd]indol-2(1H)-ones on the basis of spectroscopic analysis.
Gas Sensitivities of Polypyrrole Films to Electron Acceptor Cases
Authors: Hanawa Tetsuro , Yoneyama Hiroshi
Published: July 2006

Electropolymerized polypyrrole films exhibited noticeable gas sensitivities to electron acceptor gases such as PCl3, SO2, and NO2 at room temperature only when they were reduced electrochemically, and the resistance decrease was larger with the gas of larger electron affinity. It was also found that the resistance decrease obeyed the Elovich equation in an early stage of the gas exposure.
Light-Induced Oxidative Deposition of Polypyrrole on the Back Surface in the Dark of n-Type Silicon Wafer Photocatalysts
Authors: Yoneyama Hiroshi , Shoji Yoshihiro , Suzuki Kei-ichi
Published: July 2006

A variety of surface conditions of n-type Si wafers were prepared by etching for different time damaged surfaces that were prepared by lapping with emery papers, and the effect of flaws in the wafer surfaces on photocatalytic deposition behaviors of polypyrrole and silver from acetonitrile containing pyrrole and AgClO4 was investigated. It was found that if the front surface of the wafer to be illuminated contained a fairly high amount of defects and the back surface in the dark was defect-free, oxidative polymerization of pyrrole occurred on the back surface in the dark with the simultaneous deposition of silver on the front surface as long as the diffusion length of positive holes is greater than the thickness of Si wafers.
Ionic Partial Molar Volumes of Alkali Halides in Methanol as Evaluated from the Sedimentation Potentials
Authors: Hirakawa Hiromitu , Nomura Hiroyasu , Kawaizumi Fumio
Published: July 2006

Sedimentation potential (SP) measurements were carried out for solutions of alkali halides dissolved in methanol. With the SP data thus obtained, the partial molar volumes V2∞ of alkali halide MX, V2∞ (MX), were divided into cationic V2∞ (M+) and anionic V2∞ (X−) parts. The ionic partial molar volumes evaluated showed a reasonable agreement with each other. These values of V2∞ (M+) and V2∞ (X−) are numerically compatible with those reported earlier by Kawaizumi and Zana using the ultrasonic vibration potential method and those given more recently by French and Criss based on the apportionment of the estimated V2∞ value for the large complex [Ph4PBPh4] (J. Solution Chem., 11, 625 (1982).) The magnitude of the concentration dependence of SP was evaluated theoretically by expressing the apparent molar volume, the transport number, and the density of a solution as functions of the solute concentration.
The Syntheses of Ortho-, Meta-, and Paracyclophane-Type Thiacrown Compounds and Their Characteristics as Extractive-Spectrophotometric Reagents for Class b Metals–Silver and Copper
Authors: Muroi Motoho , Kamiki Teruo , Sekido Eiichi
Published: July 2006

Ortho-, meta-, and paracyclophane-type thiacrown compounds bearing 4-(4-nitrophenylazo)phenol as a chromogenic group were synthesized, and their characteristics as extractive-spectrophotometric reagents for the class b metals, consisting of soft Lewis acids such as silver and copper(I), were examined. Silver and copper(I) were well extracted into chloroform with all of three reagents, though especially with the metacyclophane-type reagent. The absorption maxima of silver and copper(I) complexes with the orthocyclophane-type reagents are at the longest wavelengths among the three reagents. The orthocyclophane-type reagent is adequate for the extraction and spectrophotometric measurement of copper(I), and the metacyclophane-type reagent is suitable for that of silver. The extraction behavior of copper(II) with these three reagents has been studied in order to know if the hydroxyl group participates in the formation of the metal–thiacrown complexes.
Design of the Synthetic Route for Helical Peptides. Synthesis and Solubility of Model Peptides Having a Helical Structure
Authors: Narita Mitsuaki , Kojima Yoshihisa , Isokawa Shizuko
Published: July 2006

Fragment condensations between amino- and carboxyl-components of hydrophobic decapeptides, which have a β-sheet structure in the solid state and are insoluble in DMF, NMP, and DMSO, were examined in a mixture of CH2Cl2 and TFE (4/1, v/v) using various coupling reagents. By the use of DCC and HOBt as coupling reagents, the reaction proceeded smoothly in moderate yield to give eicosapeptides. These have a stable helical structure in the solid state and are easily soluble in a variety of organic solvents. The hydrophobic eicosapeptides obtained were subjected to a successive coupling reaction in CH2Cl2 alone to give helical tetracontapeptides in high yield, which also have high solubility in various organic solvents of low polarity. The solubility of hydrophobic helical peptides presents a solubility feature of helical peptides which are obtained as peptide intermediates in protein synthesis. The synthetic strategy for helical peptides and proteins is discussed in connection with the solubility prediction method.
Aldol Addition of Butyraldehyde over Solid Base Catalysts
Authors: Zhang Geng , Hattori Hideshi , Tanabe Kozo
Published: July 2006

Aldol addition of butyraldehyde was investigated on alkaline earth oxides, zirconium oxide, and lanthanum oxide to compare the active site and mechanism with those for aldol addition of acetone. It is found that the active site is the surface O2− and the rate-determining step is α-H abstraction.
Asymmetric Oxidation of Alkyl Aryl Selenides under Sharpless Oxidation Conditions
Authors: Shimizu Toshio , Kobayashi Michio , Kamigata Nobumasa
Published: July 2006

Optically active alkyl aryl selenoxides were synthesized by the asymmetric oxidation of corresponding selenides under Sharpless oxidation conditions. The absolute configurations of the optically active alkyl aryl selenoxides prepared were estimated by comparisons of their circular dichroism spectra with those of the optically active sulfoxides.
1H NMR Conformational Study of Viologen-Linked Porphyrins
Authors: Yamamoto Yasuhiko , Noda Sumio , Nanai Norishige , Okura Ichiro , Inoue Yoshio
Published: July 2006

Novel porphyrins to which the viologen is linked (m-PCnV) were synthesized. The linkage methylene chain between the porphyrin and the bipyridine moieties was systematically changed from (CH2)3 to (CH2)6. The molecular structure of m-PCnV was characterized by 1H NMR in some detail. The orientation of the viologen with respect to the porphyrin plane in m-PCnV was semiquantitatively estimated from the porphyrin ring current induced chemical shift changes on the resonances from the viologen moiety. The NMR conformational analyses on m-PCnV in dimethyl sulfoxide and acetonitrile clearly revealed the effect of the solvent on its molecular structure.
Cyclohepta[b][1,4]benzoxazines 3. The Reaction of 6-Bromocyclohepta[b][1,4]benzoxazine with o-Aminophenol
Authors: Nozoe Tetsuo , Okai Harue , Wakabayashi Hidetsugu , Ishikawa Sumio
Published: July 2006

The reaction of 6-bromocyclohepta[b][1,4]benzoxazine (19) and o-aminophenol (3) was studied and compared with that of 3-bromo-2-methoxytropone (2) with 3. 14H-[1,4]Benzoxazino[3′,2′:3,4]cyclohepta[1,2-b][1,4]benzoxazine, 10-(o-hydroxyanilino)cyclohepta[b][1,4]benzoxazine (D), 1- and 4-formylphenoxazines and their Schiff bases (C and X) were obtained in very good yields by modifying the conditions of the reaction of 19 with 3. Structures of D, C, and their isomers were determined and the possible reaction pathways for the formation of various products are discussed.
Lanthanoid(III) Trichloride–Tin(II) Chloride Mediated Cydoaddition Reaction of α,α′-Dibromo Ketones with 1,3-Dienes or Enamines
Authors: Fukuzawa Shin-ichi , Fukushima Masakazu , Fujinami Tatsuo , Sakai Shizuyoshi
Published: July 2006

The reaction of α,α′-dibromo ketones with 1,3-dienes in the presence of CeCl3–SnCl2 in tetrahydrofuran is found to give the corresponding [3+4] cycloadduct in fair to good yields under mild conditions. Furan and cyclopentadiene serve as highly efficient receptors of the oxyallyl intermediate to give bicyclic cycloadducts. The reaction of 2,4-dibromo-3-pentanone with isoprene gives both [3+4] and [3+2] cycloadducts. [3+2] Cycloaddition proceeds similarly with enamines to afford 2-cyclopenten-1-ones after treatment with 3% ethanolic NaOH solution.
The Molecular Structure of a Schiff Base Complex, [N,N′-Ethylenebis(1-phenyl-2-imino-1-butanonato)](acetonitrile)manganese(III) Perchlorate
Authors: Xu Duanjun , Chen Banglin , Chen Ke , Chen Chaorong , Miki Kunio , Kasai Nobutami
Published: July 2006

The molecular structure of a novel Schiff base complex, [N,N′-ethylenebis(1-phenyl-2-imino-1-butanonato)](acetonitrile)manganese(III) perchlorate has been determined by X-ray diffraction method. The molecule has an elongated octahedral geometry around the metal atom.
Shift References in High-Resolution Solid-State NMR
Authors: Hayashi Shigenobu , Hayamizu Kikuko
Published: July 2006

The high-resolution solid-state 13C, 29Si, 31P, 23Na, 27Al, and 11B NMR spectra of several compounds have been measured using magic-angle sample spinning. Their isotropic chemical-shift values have been determined accurately to use as shift references in solid-state NMR; this makes comparison between literature shift data possible.
Mass Spectrum and Thermal Behavior in Solid State of N,N-Di(1-hydroxyalkyl)-2-imidazolidinone
Authors: Shimasaki Choichiro , Nakajima Kyoko , Sugimori Yuka , Tsukurimichi Eiichi , Yoshimura Toshiaki
Published: July 2006

1,3-Bis(1-hydroxyalkyl)-2-imidazolidinones (1) were prepared by the reaction of imidazolidinone with propyl-, butyl-, isobutylaldehyde. They were unstable and moisture-sensitive substances, except for 1,3-bis(1-hydroxybutyl)-2-imidazolidinone (1c). In the decomposition by the electron impact of 1 and the dimer of 1c, the molecular ion peak of 1 was not detected. The fragmentation of the imidazolidinone ring was considered to take place after a successive cleavage of the two side chains of 1. The pyrolysis reaction of 1 was found to be a thermal decomposition via a molten state after a condensation reaction. The order of the pyrolysis was calculated on the basis of DSC curves. The condensation stage for 1c apparently obeyed 1/2-order kinetics. From the dependence of the velocity on the temperature in DTA and the thermogravimetric analysis, the activation energy of decomposition was calculated; the value for the former was 67 and the latter 73 kJ mol−1. The mechanism of pyrolysis was supported by the results of the IR spectrum and chemical analysis.
Environmental Effects on the Absorption and Fluorescence Spectral Characteristics of Benzimidazole-2-carboxylic Acid and Its Ester
Authors: K. Sinha Hemant , K. Dogra Sneh
Published: July 2006

The absorption and fluorescence spectra of benzimidazole-2-carboxylic acid (BIA) and 5-chlorobenzimidazole-2-carboxylic acid (CBIA) have clearly indicated that benzimidazole (BI) ring and –COOH group are coplanar to each other and are held together in a rigid frame by intramolecular hydrogen-bonding. Dual fluorescence in observed in polar and hydrogen bonding solvents. The short wavelength fluorescence band is assigned to a structure where the –COOH group is perpendicular to the BI moiety and the long wavelength fluorescence band to the planar configuration. This is further manifested from the spectral characteristics of the ester of 5-chlorobenzimidazole-2-carboxylic acid (CBIM). Various prototropic reactions taking place in S0 and S1 states for all the three molecules are studied in the H0/pH/H− range of −10 to 16. All the dissociation constants are determined, both in the S0 and S1 states and are discussed.
The Synthesis of C-Nucleoside Precursors. II. Synthesis and Conformational Analysis of 3-(Pentahydroxypentyl)-6-phenyl-1,2,4-triazolo[3,4-a]phthalazines
Authors: A. E. Shaban Mohammed , A. M. Taha Mamdouh
Published: July 2006

Reaction of 1-hydrazino-4-phenylphthalazine with aldohexoses (d-galactose, d-glucose, d-mannose, and d-talose) and 6-deoxyaldohexoses (l-fucose and l-rhamnose) gave the colored aldehydo-sugar (4-phenyl-1-phthalazinyl)hydrazones or the colorless 3-(pentahydroxypentyl)-6-phenyl-1,2,4-triazolo[3,4-a]phthalazines. The former can be cyclized to the latter by catalytic dehydrogenation. Structure elucidation of the prepared compounds was made on the basis of their various spectral properties. The C-nucleoside precursors were further characterized as their O-acetyl derivatives and the configurational–conformational correlation of these acetates was studied. Some of the prepared compounds were screened for insectidicidal, nematicidal, and herbicidal activities and found to be inactive. They showed, however, good corrosion inhibition of aluminium in acid solutions.
Hydrothermal Synthesis of Gallium Orthophosphate Crystals
Authors: Hirano Shin-ichi , Kim Pan-chae
Published: July 2006

Synthesis and crystal growth of GaPO4 have been carried out in order to elucidate the properties of gallium orthophosphate. Single crystals were hydrothermally grown in the low temperature range from 150 to 180 °C. Solubility of GaPO4 was measured under hydrothermal conditions, and the temperature coefficient of solubility was found to be negative in H3PO4 solution. Single crystals have morphologies bounded by the major rhombohedral (10\bar1 1) faces under lower temperature and pressure conditions. Polymorphs of GaPO4 exist corresponding to low quartz type, low and high cristobalite types.
Redox Behaviors of Glassy Carbon Electrodes Modified with [Fe4X4(YC6H4-p-t-C4H9)4]2− (X, Y=S and Se) in Water
Authors: Tanaka Koji , Nakamoto Masami , Taru Yoshihisa , Tanaka Toshio
Published: July 2006

Cyclic voltammograms of glassy carbon electrode modified with iron–sulfur and iron–selenium clusters (Bu4N)2[Fe4X4(YC6H4-p-t-C4H9)4] (X, Y=S, Se) show the stable (2−/3−) redox couple in water, and the peak potentials of those redox waves are shifted by the change of pH due to reversible protonations not only of the oxidized but also of the reduced clusters. The electron transfer between the cluster and the glassy carbon plate is also influenced by the protonation equilibrium. A retardation of the electron transfer caused by the protonation of the cluster may be associated with a reorganization energy required in the redox reaction of the protonated cluster.
Determination of Individual Partial Molar Volumes of Ions in Water from Measurements of Ultrasonic Vibration Potentials
Authors: Takenaka Nobuo , Arakawa Kiyoshi
Published: July 2006

A new apparatus for measurements of ionic vibration potentials generated by the propagation of ultrasonic waves through electrolyte solutions was constructed, and used for the determination of partial molar volumes of ions in aqueous solutions of uni-univalent electrolytes. The apparatus, based on the method of ultrasonic vibration potentials (Zana and Yeager), was improved in two points through the introduction of the Doppler effect: a small measuring cell (about 50 cm3) and very low noises (50 nV). Then, measurements of temperature variation of ultrasonic vibration potentials have become possible. Partial molar volumes of hydrogen, alkali metal, and halide ions in water were determined in the range of temperature, 15–45 °C.
Formation of Magnesium and Chloroaluminium Phthalocyanine Thin Films Exhibiting an Intense Near-Infrared Absorption by Electrolysis of Surfactants with Ferrocenyl Moiety
Authors: Saji Tetsuo
Published: July 2006

Magnesium or chloroaluminium phthalocyanine (1 and 2) was dispersed to the micellar solution formed by a non-ionic surfactant with ferrocenyl moiety (3). The thin films prepared by the controlled-potential electrolysis of the micellar solution exhibited an intense nearinfrared absorption.
Photoreactions of Polyhalobenzenes in Benzene. Formation of Terphenyls
Authors: Nakada Masahiro , Miura Chihiro , Nishiyama Hideaki , Higashi Futoshi , Mori Toru , Hirota Minoru , Ishii Tetsuo
Published: July 2006

Polychlorobenzenes, polybromobenzenes, and polychloropolybromobenzenes (C6H6−nXn) were photolyzed in benzene solutions; the products were analyzed by the GC/MS method. Both dehalogenation and phenylation were shown to take place competitively, producing (poly)halobenzenes bearing one less halogen atom (C6H7−nXn−1) and (poly)halobiphenyls (C6H6−nXn−1–C6H5) as the major products. Besides these products, terphenyl was produced by a consecutive phenylation of the halobiphenyl formed. Polychlorobenzenes were shown to form the corresponding terphenyls only when a pathway via 2-chlorobiphenyl is possible; however, polybromobenzenes can produce terphenyls through any of the isomeric bromobiphenyls intermediarily formed. Isomerization through m-migration of a chlorine atom was also shown to occur to a considerably lesser extent.
The Electronic Spectra of Jet-Cooled Tropolone. Vibrational Assignment for the \ ildeA1B2–\ ildeX1A1 Transition
Authors: Sekiya Hiroshi , Nagashima Yusuke , Nishimura Yukio
Published: July 2006

The laser fluorescence excitation spectrum and the single vibronic level fluorescence spectra from the \ ildeA1B2 state of tropolone have been measured in a supersonic free jet. Some vibronic bands observed in the region of 270–450 cm−1 from the 000 band have been assigned. A tunneling doublet separation for the ν′14 in-plane ring deformation mode has been measured to be 30 cm−1, which is significantly larger than 19 cm−1 for that for the zero-point level, suggesting that the average geometry of the ν′14 mode deviates significantly from that of the zero-point level.
Synthetic, Spectroscopic and X-Ray Crystallographic Studies of Bivalent Metal Complexes with Amino Acids Having a Thiazolidine Ring. III. The Properties of Bivalent Metal Complexes with Racemic 2-Thiazolidinecarboxylic Acid and the Structure of trans-Diaquabis(2-thiazolidinecarboxylato)zinc(II)
Authors: Nagase Makoto , Yukawa Yasuhiko , Inomata Yoshie , Takeuchi Toshio
Published: July 2006

Several complexes with the formula of ML2·2H2O (HL=racemic 2-thiazolidinecarboxylic acid, (Remark: Graphics omitted.)–COOH, M=Co, Ni, Zn), anhydrous CdL2 and CdCl2(HL) were synthesized and characterized by means of their infrared absorption and reflection spectra, magnetic susceptibility, thermal analyses, and powder X-ray patterns. In addition, the crystal structure of ZnL2·2H2O was also determined. Crystals of this complex are monoclinic, with the space group P21⁄n with a=7.224(1), b=18.246(4), c=5.306(1) Å, and β=104.57(1)° and Z=2. The structure was solved by the heavy atom technique and refined by a block-diagonal least-squares method to a final R value of 0.056 for 1774 unique reflections. The zinc environment consists of two carboxylic oxygen atoms and two thiazolidine nitrogen atoms from two centrosymmetrically related organic ligands in a square-planar arrangement. Two water molecules in the axial positions complete a tetragonal bipyramidal coordination around the metal atom. No sulfur atom is coordinated to the zinc atom. The infrared absorption spectra and the structure of this zinc(II) complex are discussed in comparison with those of zinc(II) complexes with (S)-4-thiazolidinecarboxylic acid and racemic 4-thiazolidinecarboxylic acid.
Formation of (η-Cyclopentadienyl)(1,2-ethylenedithiolato, 1,2-ethylenediselenolato, and 2-selenolatoethylenethiolato-S,Se)cobalt(III) Complexes in a One-Pot-Reaction of (η-Cyclopentadienyl)(1,5-cyclooctadiene or dicarbonyl)cobalt(I) with Alkyne and a Mixture of S8 and Se8
Authors: Kajitani Masatsugu , Ochiai Ryuji , Dohki Kakushi , Kobayashi Norikazu , Akiyama Takeo , Sugimori Akira
Published: July 2006

A one-pot-reaction of (η-cyclopentadienyl)(1,5-cyclooctadiene or dicarbonyl)cobalt(I) with alkyne (diphenylacetylene and phenylacetylene) and a mixture of S8 and Se8 gives (η-cyclopentadienyl)(2-selenolatoethylenethiolato-S,Se)cobalt(III) complex in addition to the corresponding dithiolato and diselenolato complexes. When phenylacetylene was used as an alkyne, a (2-phenyl-2-selenolatoethylenethiolato-S,Se)cobalt(III) complex was formed preferentially rather than the (1-phenyl-2-selenolatothiolato-S,Se)cobalt(III) complex. The separation of the diselenolato and selenolatothiolato complexes from the dithiolato complex was successfully done by utilizing the difference in how these complexes form adducts with tributylphosphine. The dithiolato complexes have more negative reversible half-wave potentials (for reduction) than the diselenolato complexes; the selenolatothiolato complexes have intermediate half-wave potentials.
Photochemical Reaction of Benzophenones with Allylic Silanes
Authors: Takuwa Akio , Fujii Naomi , Tagawa Hiroyuki , Iwamoto Hidetoshi
Published: July 2006

Photocycloaddition and hydrogen abstraction reactions between benzophenones and allylic silanes have been investigated. The high regioselective oxetane formations were explained in terms of an additional stability due to the σSi–C–pπ hyperconjugation of β-silyl radicals in diradical intermediates. Allyl radical substituted by a trimethylsilyl group, which was generated from a hydrogen abstraction reaction, recombined with benzophenone ketyl radical at the γ position. No electron transfer products were observed in the reactions.
Synthesis of Ceratiolin, a Constituent of Ceratiola ericoides
Authors: Obara Heitaro , Onodera Jun-ichi , Yusa Katsuhiro , Tsuchiya Mitsuhiro , Matsuba Shigeru
Published: July 2006

Ceratiolin, a constituent of Ceratiola ericoides was synthesized by the methylation of 2′,3′,4′,6′-tetrahydroxydihydrochalcone, prepared by the Hoesch reaction of 1,2,3,5-benzenetetrol with 3-phenylpropionitrile. Furthermore, it was proved that ceratiolin easily forms by the oxidation of 2′,4′,6′-trihydroxy-3′,5′-dimethyldihydrochalcone.
Photoinduced Intramolecular Cyclization Reaction of 3-Substituted 2-Alkenoyl-1,4-benzoquinones
Authors: Iwamoto Hidetoshi
Published: July 2006

Irradiation of 3-alkoxy-2-alkenoyl-1,4-benzoquinones in solution gave tricyclic compounds (5H-pyrano[4,3,2-de][1,3]benzodioxin derivatives) and 3-alkylthio-2-alkenoyl-1,4-benzoquinones gave similar products (5H-pyrano[4,3,2-de][3,1]benzoxathiin derivatives). Each reaction initiates via γ-hydrogen abstraction by photoexcited quinone to produce diradical intermediates which intramolecularly cyclize to give the products.