bluuebunny/crossref_metadata_2025 huggingface dataset:
An X-Ray Diffraction Study on the Structures of Mono(glycinato)zinc(II) and Tris(glycinato)zincate(II) Complexes in Aqueous Solution
Authors: Ozutsumi Kazuhiko , Ohtaki Hitoshi
Published: July 2006

The structure of zinc(II) complexes with glycinate ion in solution was investigated by the X-ray diffraction method. The measurements were performed at 20 °C for the solutions with the Cgly⁄Czn mole ratios of 1.49 (solution A) and 5.09 (solution B), where Ci denotes the total concentration of species i. From the analysis of the radial distribution curve of solution A, in which comparable amounts of the hexaaqua- and mono(glycinato)zinc(II) complexes existed, it was found that the mono(glycinato)zinc(II) complex combined with four water molecules at the distance of (2.12±0.01) Å. The Zn–OH2 bond length within the complex was longer than that within the hexaaquazinc(II) ion (2.08 Å). The Zn–O and Zn–N distances, where O and N denote oxygen and nitrogen atoms within the glyeinate ion in the [Zn(gly)(OH2)4]+ complex, were both (2.12±0.02) Å. Thus the mono(glycinato)zinc(II) complex had a regular octahedral structure. The nonbonding Zn···C distance was found to be (2.84±0.02) Å. The X-ray diffraction data of solution B, which contained the [Zn(gly)3]− ion as a predominant species, showed that the tris(glycinato)zincate(II) complex had a regular octahedral structure with the both Zn–O and Zn–N bond distances of (2.12±0.01) Å. The nonbonding Zn···C(COO), Zn···C(CH2), and Zn···O(O=C) lengths were (2.87±0.03) Å, (2.93±0.03) Å, and (4.10±0.04) Å, respectively. The solubility of the bis(glycinato)zinc(II) complex was so low that the structural determination of the complex by the present X-ray diffraction method was not possible.
Conformational Aspect of Indazole Adenine Dinucleotides in Aqueous Solution
Authors: Tono-oka Shuichi , Azuma Ichiro , Sekikawa Isao
Published: July 2006

Conformational properties of various title compounds in aqueous solution were examined with the aid of 500 MHz 1H-NMR spectroscopy. In particular, the signals of aromatic protons on both the indazole and adenine rings were shifted to higher fields without exception, compared with the corresponding signals in indazole and adenine mononucleotides. These observations, which can be explained as resulting from diamagnetic shielding effect of the indazole and adenine rings, indicate that the base pairs in the dinucleotides are closely stacked in parallel planes. On the other hand, the average conformation of riboses were deduced from J1′,2′-values as a proportion of N\ightleftarrowsS equilibrium composition. Indazole riboses showed a roughly 50/50 equilibrium, whereas adenine riboses showed a small preference for the N-type conformer. Such a conformational state may be indispensable for taking up the strongly folded conformation between the base pairs in the dinucleotides, as judged by a somewhat favored S-type conformation of both riboses in the indazole- and adenine mononucleotides.
An Improved Preparation of the p-Tropoquinone Mono- and Diacetals by Thallium(III) Nitrate Oxidation of 2-Alkoxy-5-hydroxytropones
Authors: Takeshita Hitoshi , Mori Akira , Isayama Yasutoshi
Published: July 2006

The thallium(III) nitrate-oxidation of 2-alkoxy-5-hydroxytropones gave, in good yields, the mono- and diacetals of tropoquinones, which can be used for the introduction of oxygen functions to the seven-membered nucleus and preparation of the substituted tropoquinones. An improved synthesis of 4-methyl-p-tropoquinone or 4-methoxy-p-tropoquinone was accomplished.
Efficient Additions of an Electronically Stabilized Persistent Aminyl Radical to Conjugated Alkenes
Authors: Miura Yozo , Kunishi Teruo , Kinoshita Masayoshi
Published: July 2006

It has been found that an electronically stabilized persistent N-(4-chlorophenylthio)-3,5-di-t-butylphenylaminyl radical (1) adds to conjugated alkenes to afford 1 : 2 adducts of the alkenes and 1 in fair to excellent yields, along with small amounts of 1 : 1 adducts of the alkenes and 1.
Aggregation Behavior of Amphiphiles Functionalized with Dipeptide Segments and Enantioselective Ester Hydrolysis in Their Bilayer Membranes
Authors: Murakami Yukito , Nakano Akio , Ikeda Hidetsugu , Imori Toru , Akiyoshi Kazunari
Published: July 2006

Four amphiphiles having dipeptide segments, which consist of one histidyl residue and another amino acid residue, and the dihexadecyl moiety for the double-chain segment (N+C5AlaHis2C16, N+C5LeuHis2C16, N+C5PheHis2C16, and N+C5HisAla2C16) were synthesized, and the aggregate morphology of them was characterized by electron microscopy and differential scanning calorimetry. The amphiphiles, which have the histidyl residue bound to the dihexadecylamine component (N+C5AlaHis2C16, N+C5LeuHis2C16, N+C5PheHis2C16) formed both multi- and single-walled aggregates in the aqueous dispersion state, while their sonicated solutions involved only single-walled vesicles. On the other hand, the amphiphile, which has the alanyl residue bound to the dihexadecylamine component (N+C5HisAla2C16) afforded tubular aggregates in the aqueous dispersion. The hydrolysis of enantiomeric esters of various hydrophobic nature, which was carried out in the single-walled vesicles, showed relatively small enantioselectivity. The reasons for such catalytic performance of the vesicles were discussed from the kinetic and mechanistic viewpoints; the kinetic analysis being carried out on the basis of the organic pseudo-phase concept.
Syntheses of Benzilic Acids through Electrochemical Reductive Carboxylation of Benzophenones in the Presence of Carbon Dioxide
Authors: Ikeda Yoshikazu , Manda Eiichiro
Published: July 2006

Reaction conditions for the electrochemical synthesis of benzilic acid (2a) under the atmosphere of carbon dioxide was investigated from the preparative points of view. The highest yield of 2a (86%) was obtained under the following conditions; cathode: mercury, electricity passed: 2.3 F/mol, constant current density: 2.5 mA/cm2, benzophenone (1a) (8.2×10−3mol), electrolyte(KI, 1.7×10−2mol) in DMF (50 ml). This method and conditions were applied to the syntheses of twelve benzilic acids (2b–2m) and yielded acids in the range of 10–92%. The yields were strongly depended on the electronic effect of substituents and benzilic acids were not obtained when the ring substituent was NO2, OH, or Br group.
Effective Cleavage of 7-Alkoxytricyclo[6.4.0.02,7]dodecan-3-one System
Authors: Kojima Tsutomu , Inouye Yoshinobu , Kakisawa Hiroshi
Published: July 2006

Several effective methods for the cleavage of the cyclobutane ring in 7-alkoxytricyclo[6.4.0.02,7]dodecan-3-one system are described. These involve reactions with hydriodic acid, with trimethylsilyl trifluoromethanesulfonate, and with KOH in H2O–DMSO via a lactone derivative.
Dialkylcarbamato Complexes of Ni(II), Zn(II), and Cd(II)–Tetraazacycloalkanes Obtained from CO2-Uptake, and X-Ray Structure of (Diethylcarbamato)((7RS,14RS)5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraaza-cyclotetradecane)nickel(II) Perchlorate
Authors: Ito Haruko , Ito Tasuku
Published: July 2006

Nickel(II), zinc(II), and cadmium(II) complexes of certain tetraazacycloalkanes (L), [M(L)](ClO4)2, take up CO2 as R2NCO2− to give carbamato complexes, [M(O2CNR2)(L)]+, where L=(7RS,14RS)-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (L1) for M=Ni2+, and L=1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane (L2) for M=Ni2+, Zn2+, and Cd2+. The resulting complexes have been characterized by means of IR, and NMR or electronic spectroscopy. X-Ray analysis of [Ni(O2CN(C2H5)2)(L1)]ClO4 (monoclinic C2/c, a=15.842(3), b=13.675(3), c=13.753(2) Å, β=109.94(1)°) shows that it is a discrete six-coordinate complex with cis-NiO2N4 geometry, and the carbamato ligand is bidentate. Desired carbamato complexes were hardly obtained with [M(L)]2+ containing tetraaza macrocyclic ligand which favors square-planar coordination. All the data indicate that carbamate ions chelate the metals, and thus use of tetraazacycloalkanes which fold readily is essential for this type of CO2 uptake.
Infrared Spectrum of Dichloroborane Produced by CO2 Laser Enhanced Reaction
Authors: Lee Kuk-Haeng , Takeo Harutoshi , Kondo Shigeo , Matsumura Chi
Published: July 2006

Infrared spectra of HBCl2 and DBCl2 produced by a TEA CO2 laser enhanced reaction of BCl3 and H2/D2 have been observed by an FT-IR spectrometer at a resolution of 0.12 cm−1. A detailed analysis has been carried out for the ν1 band of HBCl2 to obtain the precise molecular parameters, and they are compared with the microwave data. The fundamental frequencies other than the ν3 band have all been determined. These frequency data combined with the results of an ab initio MO calculation have yielded the general symmetry force field through a least squares method. Some characteristic features on the CO2 laser reaction of BCl3 and H2 are also discussed.
Synthetic Studies of Rifamycins. VII. A Facile Synthesis of the Aromatic Chromophore of Rifamycin S through a Rifamycin W Aromatic Segment
Authors: Nakata Masaya , Wada Shigeru , Tatsuta Kuniaki , Kinoshita Mitsuhiro
Published: July 2006

The intact aromatic chromophore of rifamycin S, 7-amino-2,5-dihydroxy-2,4-dimethyl-naphtho[2,1-b]furan-1,6,9(2H)-trione, was synthesized through the rifamycin W aromatic segment, 1-[5,8-dimethoxy-2,4-bis(methoxymethoxy)-3-methyl-6-nitro-1-naphthyl]-1-propanone which was prepared in 9 steps and 29.6% overall yield from 2,6-bis(benzyloxy)-3,5-dibromotoluene and furan.
Synthesis of 5-(Substituted Styryl)-2-aminotropones
Authors: Imafuku Kimiaki , Kobayashi Toshio , Matsumura Hisashi
Published: July 2006

The methylation of 4-styryltropolones with diazomethane afforded 2-methoxy-4-styryltropones (2a–g) and 2-methoxy-6-styryltropones. The reactions of 2a–g with hydrazine gave 2-hydrazino derivatives, which were converted to 2-chloro derivatives 5a–g. Ammonolysis of 5a–g afforded 2-amino-5-styryltropones (7a–g) by ciné substitution reaction. The compounds 7a–g were hydrolyzed to give the corresponding 5-styryltro-polones. Some interesting by-products were also found in these synthetic processes.
Synthetic Inorganic Ion-exchange Materials. XXXX. Ion Exchange Properties of Tin(IV) Antimonate for Alkaline Earth and Transition Metal Ions and Its Application to Metal Separations
Authors: Abe Mitsuo , Furuki Noboru
Published: July 2006

Ion-exchange selectivities of alkaline earth and transition metal ions on tin(IV) antimonate cation exchanger were investigated in nitric acid media. The selectivity sequences were found to be; Mg2+<Ca2+<Sr2+<Ba2+ for alkaline earth metal ions and Ni2+<Mn2+<Cd2+<Co2+<Cu2+<Zn2+ for transition metal ions. The separation factors for neighboring pairs on the exchanger gave larger values than those on the ion-exchange resin of a strong acid type. The effective separations of Mg2+–Ca2+, Sr2+–Ba2+, and Na+–Cs+, Sr2+ have been achieved with a small column (5cm×0.5 cm i.d.).
Phosphorescence from Biacetyl and Benzophenone Surfaces by Collision with the T1 State of Benzene
Authors: Ohshima Shigeru , Kondow Tamotsu , Kuchitsu Kozo
Published: July 2006

Benzene molecules in the lowest-excited triplet state, T1, were allowed to collide with biacetyl and benzophenone surfaces, and phosphorescence from the surface due to energy transfer from the T1 state of benzene was observed. The possibility of application of this method to detection of metastable species is discussed.
Synthesis and Magnetism of Trinuclear Copper(II) Complexes with a Salen-like Schiff Base and a Tertiary Diamine
Authors: Handa Makoto , Okawa Hisashi , Kida Sigeo
Published: July 2006

Trinuclear Copper(II) complexes [{Cu(sb)}2Cu(da)](ClO4)2 have been synthesized by the use of a copper(II) complex with a salen analog ([Cu(sb)]) and a diamine (da) such as bpy or phen. Cryomagnetic investigations revealed the operation of an antiferromagnetic spin-exchange interaction (–J=26–78 cm−1) between the adjacent copper ions.
Behavior of Trifluoroacetohydrazonoyl Bromide in Basic Media
Authors: Tanaka Kiyoshi , Maeno Seiji , Mitsuhashi Keiryo
Published: July 2006

The bromide 1 was treated with sodium methoxide or phenoxide to give exclusively the corresponding substituted product. The predominant formation of the substituted products was also recognized with regard to various amines. However, the reaction with triethylamine proceeded more complicatedly to give the products via reduction process together with a trace amount of the dimer of N-phenyl-C-(trifluoromethyl)nitrilimine.
Dichlorotetrakis(isocyanide)dipalladium(I) Containing a Metal–Metal Bond
Authors: Yamamoto Yasuhiro , Yamazaki Hiroshi
Published: July 2006

The structure of [{PdCl(t-BuNC)2}2] has been determined by X-ray diffraction. A metal–metal bond joins two Pd atoms, each of which possesses an essentially square-planar coordinate site. The photochemical reaction of [{PdCl(RNC)2}2] in CH2Cl2 led to a cleavage of the metal–metal bond to give trans-[PdCl2(t-BuNC)2].
Boron Trifluoride Etherate-catalyzed Backbone Rearrangement of 5α,10α-Epoxyalnusan-3β-yl Acetate and Partial Synthesis of Isomultiflorenol
Authors: Takai Masaki , Tori Motoo , Tsuyuki Takahiko , Takahashi Takeyoshi , Itai Akiko , Iitaka Yoichi
Published: July 2006

Epoxidation of alnus-5(10)-en-3β-yl acetate with m-chloroperbenzoic acid gave a 5α,10α-epoxide, treatment of which with boron trifluoride etherate afforded multiflora-5,8-dien-3β-yl acetate. On hydrogenation and hydrolysis, the diene gave isomultiflorenol.
X-Ray Photoelectron Diffraction (XPED) Studies on Metal Oxide Surfaces. (I) Analysis of the XPED Patterns from TiO2(001) and α-Al2O3(0001) by the Single Scattering Calculation
Authors: Tamura Koji , Owari Masanori , Kudo Masahiro , Nihei Yoshimasa
Published: July 2006

X-Ray photoelectron diffraction (XPED) measurements were applied to the (001) surface of TiO2 rutile and the (0001) surface of α-Al2O3 in order to examine the applicability of XPED to metal oxides. Obtained XPED patterns were compared with the results of theoretical calculations based on a single scattering model. The calculated patterns from both oxides agreed with the experimental patterns. It was revealed from theoretical calculations that the four oxygen atoms in the unit cell of TiO2 made different contributions to the XPED pattern which reflected different atomic environments. The same calculation was also made on titanium in TiO2, and on aluminum and oxygen in Al2O3. This clarified the contributions of nonequivalent sites of emitter atoms to the main peaks in the experimental XPED patterns. In comparison with the crystal structures, some peaks could be attributed to some specific emitters or specific emitter-scatterer pairs. This analysis was found to be useful to interpret experimental XPED patterns, and is expected to be applied to the analysis of the structures of surfaces or interfaces related to such phenomena as selective desorption or substitution of specific site of atoms.
The Curve Fitting Analysis of D.c. and A.c. Voltammograms of a Two-step Surface-redox Reaction. The Application to the Surface-redox System of Adriamycin Adsorbed on a Pyrolytic Graphite Electrode
Authors: Kano Kenji , Konse Tomonori , Kubota Tanekazu
Published: July 2006

A theoretical study of the two-step surface-redox reaction (Oad+n1e\ightleftharpoonsSad, Sad+n2e\ightleftharpoonsRad) was performed using d.c. voltammetry. A new method based on a non-linear least-squares curve fitting of cyclic d.c. and a.c. voltammograms was proposed for determining electrochemical parameters and was successfully applied to the surface-redox system of the quinone moiety of adriamycin adsorbed on a pyrolytic graphite electrode.
Differential Pulse Polarographic Determination of Lead Using Coprecipitation with Hafnium Hydroxide
Authors: Ueda Joichi , Kita Chikako
Published: July 2006

A differential-pulse polarographic determination of trace amounts of lead using coprecipitation with hafnium hydroxide has been studied. Hafnium hydroxide is effective as a collector of lead and makes 2.5 to at least 1250 μg of lead coprecipitate quantitatively from 100–500 cm3 of sample solution. The formed precipitate is easily dissolved with hydrochloric acid and the presence of hafnium does not affect to the polarogram of lead. The effects of twenty-three diverse ions such as aluminium, zinc, cadmium, chromium(III), manganese(II), cobalt, and nickel were examined, and it was found that the presence of tin(IV), copper, and iron(III) interfered with the determination, even in small amounts. The recommended procedure for the determination is as follows. To a sample solution containing lead, 5 mg of hafnium is added and the pH is adjusted to about 10 with 1 : 1 aqueous ammonia. Then, the precipitate is filtered with a glass filter and dissolved with 2 cm3 of concd hydrochloric acid. After the solution is diluted to 25 cm3 with distilled water and deaerated with pure nitrogen for 5 min, lead is determined by the current peak height at −0.41 V.
Gas Chromatography–Mass Spectrometry of Trimethylsilylated Imino Derivatives of Alanine
Authors: Kawashiro Katsuhiro , Morimoto Shiro , Yoshida Hideyuki
Published: July 2006

Trimethylsilylation of seven imino derivatives of alanine with N,O-bis(trimethylsilyl)trifluoroacetamide in acetonitrile was studied. The imino derivatives include 2,2′-iminodipropionitrile (1), 2,2′-iminodipropionamide (2), 2,2′-iminodipropionic acid (3), 2-(1-cyanoethylamino)propionamide (4), 2-(1-cyanoethylamino)propionic acid (5), 2-(1-carbamoylethylamino)propionic acid (6), and 3,5-dimethyl-2,6-piperazinedione (7). The reaction products were identified by gas chromatography–mass spectrometry. Under the present reaction conditions (at 100 °C for 30 min), hydrogen atoms of carboxyl and carbamoyl groups and an imide hydrogen were readily replaced by the trimethylsilyl (TMS) group, but imino hydrogens were not replaced because of the steric hindrance of N-substituent group. For the carbamoyl group, only one hydrogen was replaced. Consequently, 1 was not trimethylsilylated. Furthermore, no definite trimethylsilylation products were obtained for 4. Upon electron impact at 70 eV, 2, 3, and 5–7 gave rather simple spectra with molecular (M+) and M −15 (loss of CH3) ions characteristic of TMS derivatives. A fragment, M −117 (loss of COOTMS) or M −116 (loss of CONHTMS), was very prominent for 2, 3, 5, and 6. Other important ions such as m/z 70 were noted. Preparations and properties of some of the imino derivatives are also described.
Alkylation and Oxidation of 6,7-Dihydro-6-methyl-5H-dibenzo[b,g][1,5]thiazocine. Selective Oxidation of the Sulfide Moiety by Transannular Participation of the Amino Group
Authors: Ohkata Katsuo , Takee Kohichi , Akiba Kin-ya
Published: July 2006

6,7-Dihydro-6-methyl-5H-dibenzo[b,g][1,5]thiazocine (7) was prepared by cyclization of the corresponding amino alcohol using thionyl chloride in acetonitrile. Methylation of 7 gave N,N-dimethyl derivative (8) as the sole product. Treatment of 7 with various oxidizing reagents, however, afforded the corresponding sulfoxide (9) and/or N-oxide (13), and sulfone (14) depending on the kind of reagent. Oxidation of 7 with sodium periodate furnished N-oxide (13) in 72% yield as a major product along with sulfoxide (9) in 12% yield, while 9 was obtained as a major product (76%) by oxidation with sodium hypochlorite together with a small amount of methoxysulfonium derivative (15) in aqueous methanol. The acceleration in oxidation of 7 compared with diphenyl sulfide as well as production of 15 is ascribed to the transannular participation of the amino group with the chlorosulfonio group or intermediacy of a sulfurane. In addition, structural features of 9 and 15 have been investigated by means of 1H NMR and evidence for the transannular interaction between the two heteroatoms is presented.
Studies of Unusual Amino Acids and Their Peptides. XVII. The Synthesis of Peptides Containing N-Carboxymethyl Amino Acids. II
Authors: Miyazawa Toshifumi , Hiramatsu Shin’ichi , Tsuboi Yasuhiro , Yamada Takashi , Kuwata Shigeru
Published: July 2006

The synthetic routes were investigated to four kinds of tetrapeptides made up of three usual amino acid residues and one N-carboxymethyl (Cm-) amino acid residue. The application of vacuum distillation made the isolation of a Cm-amino acid diester more convenient and efficient compared with the chromatographic methods which had been used previously. The efficiency of peptide bond formation at the imino group of a Cm-amino acid by the acid chloride method was remarkably improved under suitable reaction conditions. In the elongation of the peptide chain from a peptide containing a Cm-amino acid at the C-terminal position, the coupling efficiency was usually poorer than that in the case of the corresponding peptide composed only of the usual amino acid residues, and it depended greatly on the coupling methods, the 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide–1-hydroxybenzotriazole method being generally the most desirable.
Heterogeneous Photocatalytic Decomposition of Phenol over TiO2 Powder
Authors: Okamoto Ken-ichi , Yamamoto Yasunori , Tanaka Hiroki , Tanaka Masashi , Itaya Akira
Published: July 2006

The photocatalytic decomposition of phenol in oxygenated aqueous suspensions of lightly-reduced anatase TiO2, being the most satisfactory among the semiconductors investigated from the standpoint of the photocatalytic activity and stability, has been investigated at the optimum pH 3.5. The products at the initial stage of the reaction were hydroquinone, pyrocatechol, 1,2,4-benzenetriol, pyrogallol, and 2-hydroxy-1,4-benzoquinone. These intermediates underwent further photocatalytic oxidation via acids and/or aldehydes finally into CO2 and H2O. A reaction scheme involving hydroxyl radicals as real reactive species has been proposed. Although H2O2 was formed via O2\ewdot produced by electron trapping of adsorbed oxygen, its concentration remained constant at a low value during the reaction. About 0.7 mole of O2 was consumed for the consumption of one mole of phenol at the initial stage of the reaction. These results indicated that hydroxyl radicals were formed not only via holes but also via H2O2 from O2\ewdot. It was interesting from the viewpoint of wastewater treatment that phenol was completely mineralized to CO2 in the presence of TiO2 powder under solar irradiation without both aeration and mixing of the solution.
Cadmium-photosensitized Reaction of γ-Valerolactone and α-Methyl-γ-butyrolactone
Authors: Yamamoto Shunzo , Takahoso Hiroshi , Sueishi Yoshimi , Nishimura Norio
Published: July 2006

The cadmium-photosensitized reactions of γ-valerolactone and α-methyl-γ-butyrolactone have been investigated. The obtained products in both cases were carbon monoxide, ethylene, propylene, acetaldehyde, and 2-methyloxetane. The dependence of the yields of ethylene and propylene on the total pressure suggests the existence of a biradical and an energized intermediate. Possible mechanisms are discussed.
Adsorption Equilibria of Copper on Octadecylsilica Gel in the Presence of Acetylacetone
Authors: Kato Masanao
Published: July 2006

The solid-liquid adsorption equilibria of copper with acetylacetone between octadecyl-bonded silica (ODS) gel and aqueous solution were investigated by a batch method at 298±1 K. It is found that a 1 : 1 complex of copper with acetylacetone is adsorbed on the gel surface.
A Method for Preparing A Large Sized, Uniform and Stable Built-up Film of 109Cd Icosanoate as A Radioactive Source by Utilization of an Extremely Small Amount of Substrate Solution
Authors: Iwahashi Makio , Naito Fujio , Watanabe Norifumi , Seimiya Tsutomu , Morikawa Naotake , Nogawa Norio , Ohshima Takayoshi , Kawakami Hirokane , Ukai Kumataro , Sugai Isao , Shibata Seiichi , Yasuda Takahiro , Shoji Yoshihiko , Suzuki Takeshi , Nagafuchi Teruyasu , Taketani Hiroshi , Matsuda Takeshi , Fukushima Yasutaka , Fujioka Manabu , Hisatake Kazuo
Published: July 2006

A stable radioactive source in vacuo was obtained by a modified horizontal lifting method of Langmuir-Blodgett (L/B) film. In spite of the slight consumption of the substrate solution (only 2–2.5 ml) for preparing a 15 mm×25 mm sized L/B film containing four molecular layers of 109Cd icosanoate, the deposition of the film was complete. The reliability of the deposited films by this method was confirmed by their radioactivities, deposition ratios and autoradiographs. The condition to obtain a larger sized homogeneous L/B film (20–25 mm×102 mm) was also examined. Two or four molecular layers of nonradioactive Cd icosanote deposited on the L/B film of 109Cd icosanoate did not influence the intensity of the γ-ray of 88.0 KeV. Concequently, it is possible to obtain the high radioactive source by the deposition of the multilayers of 109Cd icosanoate. Spectra of L2 and L3 conversion electrons from the 109Cd in its built-up film were also determined. In conclusion, the present depositing method for the L/B film is excellent for the manufacturing the radioactive source and thought to be also applicable for the deposition of other valuable materials.
Studies on the Electronic Absorption Spectra of 2,2′-Bithienyl and Some of Its Derivatives. A Molecular Orbital Treatment
Authors: Abu-Eittah Rafie H , Al-Sugeir Fakhreia A
Published: July 2006

The electronic absorption spectra of 2,2′-bithienyl and a number of its derivatives have been investigated. The predominant conformer as well as the polarity of the molecule were predicted from the spectrum. Molecular orbital calculations were performed on different conformers of 5-formyl-2,2′-bithienyl and the s-trans geometry proved to be the predominant conformer of the molecule. A good agreement is observed between calculated and observed transition energy and intensity.
Cobalt-catalyzed Hydroesterification of Formaldehyde Dialkyl Acetals
Authors: Murata Kazuhisa , Matsuda Akio , Masuda Takashi
Published: July 2006

Co2(CO)8-organic amine system was found to be an effective catalyst for the production of alkoxyacetic ester from formaldehyde dialkyl acetals and CO; this is the first example of homogeneous hydroesterification of acetal.
A Correlation of Electrochemical Oxidation and Ionization Potentials of Group 4B Dimetals
Authors: Mochida Kunio , Itani Atsuko , Yokoyama Michiyo , Tsuchiya Tohru , Worley Shelby D , Kochi Jay K
Published: July 2006

Correlations of ionization potentials and electrochemical oxidation potentials for group 4B dimetals were obtained.
Preparation of Vanadium–Phosphorus Mixed Oxide (P/V=1) Catalysts and Their Application to Oxidation of Butane to Maleic Anhydride
Authors: Shimoda Tomoaki , Okuhara Toshio , Misono Makoto
Published: July 2006

Several vanadium–phosphorus mixed oxides with a P/V ratio=1 have been prepared and the relationships between the structure of catalyst and the catalytic function for the selective oxidation of butane to maleic anhydride were examined. As revealed from XRD, IR, XPS, and redox titration studies, five among them were presumably composed of crystalline single phases, that is, α-VOPO4, β-VOPO4, and (VO)2P2O7 as well as unknown phases X1 and X2. The valences of the vanadium of these catalysts were close to five, except for (VO)2P2O7 (the valence was four). These phases were prepared, respectively, by controlling the kind of precursors and the calcination conditions. The selectivity to maleic anhydride differed markedly among these catalysts, although the rate did not change much when it was normalized to surface area. The selectivity at 440 °C was less than 20% for α- and β-VOPO4, 40% for X1 and X2, and 70% for (VO)2P2O7. Amorphous phases having V4+ were much less selective than (VO)2P2O7. No structural changes of the catalysts after use were observed in the cases of α-, β-VOPO4, and (VO)2P2O7. Therefore, the effective phase for selective oxidation of butane to maleic anhydride was speculated to be a phase like (VO)2P2O7 in which the valence of vanadium is four and the structure is stable under the reaction conditions.
Preparation of Polyoxa-1,n-dithia[n](1,1′)ruthenocenophanes and the Structural Studies of Their Metal Complexes
Authors: Akabori Sadatoshi , Munegumi Hiroyuki , Habata Yoichi , Sato Sadao , Kawazoe Kayoko , Tamura Chihiro , Sato Masaru
Published: July 2006

Polyoxa-1,n-dithia[n](1,1′)ruthenocenophanes were prepared by treatment of 1,1′-ruthenocenedithiol with α, ω-dibromo polyethers. The ruthenocenophanes formed efficiently complexes with soft ions, but not with hard and borderline cations. The 1H- and 13C-NMR spectral data of the silver(I) ion-complexed ruthenocenophanes suggested a partial electron-transfer interaction between the ruthenium atom of the ruthenocene nucleus and the incapsulated silver(I) ion. The crystal structure of the 1:1 complex of 4,7,10,13-tetraoxa-1,16-dithia[16](1,1′)ruthenocenophane with mercury(II) chloride was determined by the X-ray method. The crystals are triclinic, space group P\bar1, with a=13.722(3), b=11.678(4), c=8.179(2) Å, α=102.69(3), β=72.82(2), γ=100.73(2)°, Z=2, Dx=2.11 g cm−3. The mercury(II) cation and the two chloride ions are situated in the central cavity of the macrocyclic moiety and at the apexes, respectively. The distance between the ruthenium atom of a ruthenocene nucleus and the incapsulated mercury(II) ion is 4.846 (2) Å which is too long for direct metal–metal interaction.
Development and Application of Organic Reagents for Analysis. VI. Synthesis and Fluorescence Spectral Properties of 2-(4-Substituted phenyl)benzofurans
Authors: Akiyama Shuzo , Akimoto Hiroyuki , Nakatsuji Shin’ichi , Nakashima Kenichiro
Published: July 2006

A synthesis of fifteen kinds of 2-(4-substituted phenyl)benzofurans (4n) was carried out and their fluorescence spectral properties were investigated concerning their applicability as organic reagents for analyses.
Molecular Complexes of Hydroxy Host Systems with Alcohols. X-Ray Crystal Structures of 1,1,6,6-Tetrakis(2,4-dimethylphenyl)-2,4-hexadiyne-1,6-diol–Ethanol (1:2), 1,1-Bis(2,4-dimethylphenyl)-2-butyn-1-ol–Ethanol (1:1), and 9-(1-Propynyl)-9-fluorenol–Methanol (1:1)
Authors: Toda Fumio , Tanaka Koichi , Mak Thomas C W
Published: July 2006

The structures of a 1:2 molecular complex(I) of 1,1,6,6-tetrakis(2,4-dimethylphenyl)-2,4-hexadiyne-1,6-diol with ethanol, a 1:1 complex(II) of 1,1-bis(2,4-dimethylphenyl)-2-butyn-1-ol with ethanol, and a 1:1 complex(III) of 9-hydroxy-9-(1-propynyl)fluorene with methanol have been determined by X-ray crystallography. The crystal data are: I, C42H50O4, P\bar1, a=8.249(3), b=9.522(5), c=14.803(8)Å, α=100.95(4), β=110.82(4), γ=113.08(3)°, Z=1, and Rf=0.105 for 1834 observed Mo Kα data; II, C22H28O2, P\bar1, a=8.142(2), b=11.281(3), c=l2.262(4)Å, α=102.76(2), β=97.08(2), γ=111.19(2)°, Z=2, and Rf=0.073 for 2104 data; III, C17H16O2, P21/a, a=8.641(5), b=10.883(5), c=30.63(2)Å, β=92.88(4)°, Z=8, Rf=0.154 for 1885 data. The crystal structures of I and II are closely related and both feature planar hydrogen-bonded (OH)4 rings centered at centrosymmetric sites. In III, the fluorene and methanol molecules belong to two independent sets, and the molecular components in each set are alternately linked by hydrogen bonds to form infinite zigzag chains parallel to the a axis.
The Crystal and Molecular Structures of Esculetin 6-Glucoside and 7-Glucoside
Authors: Ueno Katsuhiko , Shiraki Masaru , Sato Mitsuhiko , Saito Norio
Published: July 2006

The structures of two dihydroxycoumarin glucosides, esculetin 6-glucoside (E6G) and escultin 7-glucoside (E7G) have been determined by the X-ray analysis. The crystal data are: E6G, C15H16O9·1.5H2O, orthorhombic P212121 with a=11.358(2), b=36.850(9), c=7.663(1) Å and Z=8: and E7G, C15H16O9·2H2O, orthorhombic P212121 with a=4.507(1), b=13.077(3), c=27.748(5) Å and Z=4. Both structures were solved by the direct method and refined by the least-squares to the final R values of 0.073 (2036 reflections) for E6G and 0.069 (1037 reflections) for E7G. The geometries of the glucosyl linkages in E6G and E7G are different: the torsion angles around the glucosidic C–O bond are −58.2° and 14.3° for the two crystallographically independent E6G molecules and 9.9° for E7G. The glucosidation at the 6-hydroxyl group causes little effect on the conjugation of the coumarin moiety, whereas the conjugation is greatly decreased in the glucosidation at 7-hydroxyl group. This fact suggests that E6G is energetically more stable than E7G. The enzymatic transglucosidation from 7- to 6-hydroxyl group may proceed utilizing such an energy difference.
The Crystal and Molecular Structure of syn-[2.2](1,4)Anthracenophane and Its Photoisomer
Authors: Toyoda Toshihiro , Kasai Nobutami , Misumi Soichi
Published: July 2006

Molecular structure of syn-[2.2](1,4)anthracenophane (1) and its photoisomer (2) have been determined by means of X-ray diffraction; 1, monoclinic, space group A2, a=25.539(2), b=8.152(1), c=20.561(3) Å, β=106.03(1)° (−149°C), Z=8; 2, monoclinic, space group P21/c, a=8.065(6), b=12.963(9), c=19.580(5) Å, β=91.46(5)°, Z=4. The structure of 1 was solved by the vector search method and 2 by the direct method. Both structures were refined including all hydrogen atoms by the block-diagonal least-squares procedure: R=0.053 and 0.043 for 4413 and 2003 observed reflections for 1 and 2, respectively. Two anthracene nuclei, connected by ethylene bridges at the 1 and 4 positions, in each of the two independent molecules (A and B) of 1 are approximately parallel. However, their overlappings differ slightly. In the photoisomer 2 the two anthracene nuclei are bound by newly formed bonds at the 9 and 10 positions: bond distances are 1.628(5) and 1.637(5) Å whereas the corresponding nonbonded distance in 1 are 3.312(6) and 3.301(6) Å (A molecule) and 3.357(6) and 3.366(6) Å (B molecule).
Fischer Tropsch Reaction over Reduced Molybdenum Catalysts Derived from Various Heteropoly Compounds
Authors: Miura Hiroshi , Ishiguro Hitoshi , Osawa Masashi , Sasagawa Kazunori , Sugiyama Kazuo , Matsuda Tsuneo
Published: July 2006

The Fischer-Tropsch reaction was examined over reduced molybdenum catalysts using heteropoly compounds as catalyst precursors. Improvement in reducibility was realized by the use of heteropoly compounds. Metallic molybdenum powder with a very large surface area was obtained by the reduction of H3PMo12O40. Its catalytaic activity was one order higher than conventional Mo catalysts. Using different salts of 12-molybdophosphoric acid, various additives were introduced under equivalent conditions and their addition effects were studied.
Electrochemical Epoxidation and Carbon–Carbon Bond Cleavage for the Preparation of 3-Methyl-4-oxo-2-phenyl-4H-1-benzopyran-8-carboxylie Acid from 3-Methyl-2-phenyl-8-(1-propenyl)-4H-1-benzopyran-4-one
Authors: Uneyama Kenji , Masatsugu Yosinori , Torii Sigeru
Published: July 2006

Electrooxidative carbon–carbon bond cleavage is useful for the preparation of 3-methyl-4-oxo-2-phenyl-4H-1-benzopyran-8-carboxylic acid (1b) from 3-methyl-2-phenyl-8-(1-propenyl)-4H-1-benzopyran-4-one (2). Olefin 2 was transformed into 3-methyl-8-(1,2-epoxypropyl)-3-methyl-2-phenyl-4H-1-benzopyran-4-one (3) by the electrochemical bromohydrination in an MeCN–H2O–H2SO4–NaBr–(Pt) system followed by treatment of aqueous sodium hydroxide (94%). The epoxide 3 was electrooxidized in an MeOH–H2SO4–(C) system, affording 8-formyl-3-methyl-2-phenyl-4H-1-benzopyran-4-one (4) in 83% yield. Hydrogen peroxide oxidation of 4 in refluxing 2-butanone gave 1b in 86% yield.
Stability and Distribution Studies on Semicrystalline Tin(IV) Selenophosphate. Separation of Metal Ions
Authors: Nabi Syed Ashfaq , Siddiqi Zia Mahmood , Rao Rifaqat A K
Published: July 2006

Tin(IV) selenophosphate has been synthesized by mixing 0.05 mol dm−3 aqueous solutions of tin(IV) chloride, sodium selenite and sodium dihydrogenphosphate in 1:1:2 ratio at pH=0. The chemical and thermal stabilities are investigated. A tentative formula has been proposed for tin(IV) selenophosphate on the basis of chemical composition, pH titration, IR spectrum and thermogravimetric anslysis. The distribution coefficients of metal ions have been determined in DMF, DMSO, DMF–HNO3, and DMSO–HNO3 media. A number of binary, ternary, and quaternary separations of metal ions have been achieved on the columns of tin(IV) selenophosphate.
Mono(cyclopentadienyl)titanium(IV) Derivatives with Heterocydic Thioketones
Authors: Pandey Om Prakash , Sengupta Soumitra Kumar , Tripathi Satish Chandra
Published: July 2006

The reactions of mono(cyclopentadienyl)titanium(IV) trichloride with three important series of heterocyclic thioketones, viz., triazolinethiones 4-amino-, 4-benzylideneamino-, 4-furfurylideneamino-, and 4-salicylideneamino-5-trifluoromethyl-1,2,4-triazoline-3-thiones, thioxoquinazolones (3-methyl-, 3-phenyl-, and 3-(o-tolyl)-2-thioxo-4-quinazolones), and oxadiazolethiones (5-phenyl-, 5-(p-nitrophenyl), and 5-(p-chlorophenyl)-1,3,4-oxadiazole-2-thiones, have been studied in anhydrous dichloromethane. The reaction products have been characterized on the basis of elemental analyses, electrical conductance, magnetic susceptibility and spectral (electronic, infrared, and 1H NMR) data. Proton NMR spectra indicate that there is rapid rotation of the cyclopentadienyl ring around the metal ring axis on the NMR time scale at 28 °C.
Spectroscopic Studies of Photochemical Reactions in Organic Solids. Photodimerization of p-Formylcinnamic Acid
Authors: Ghosh Urmi , Misra Tridibendra Narayan
Published: July 2006

Raman phonon spectroscopy and electronic absorption and emission spectroscopy have been used to study the mechanism of reaction and the role of electron–phonon coupling in determining the photoreactivity of p-formylcinnamic acid (p-FCA) in the crystalline state. Raman and infrared spectroscopy in the internal vibration region have been used to characterize the reactant p-FCA and the dimeric product t-3,t-4-bis(p-formylphenyl)-ν-1,c-2-cyclobutanedicarboxylic acid. Phonon spectroscopy reveals that the reaction proceeds principally by a heterogeneous mechanism though a homogeneous mechanism in the initial stage of short time domain can not be ruled out. The electronic spectroscopy suggests a strong electron–phonon coupling in the monomer crystal.
Fluorescence Spectra of Anthracene Liquid
Authors: Iwasaki Noriko , Horiguchi Rumiko , Maruyama Yusei
Published: July 2006

An excimer-like fluorescence band at 470 nm was observed for anthracene liquid. A distinct shoulder at 414 nm was recognized in the absorption spectrum of anthracene liquid. These results suggest the existence of dimeric aggregates in this liquid.
The Determination of the Dissociation Constants of Picric Acid and 2,2′,4,4′,6,6′-Hexanitrodiphenylamine in Ketone–Water Mixtures
Authors: Iwachido Tadashi , Oosawa Shinji , Tôei Kyoji
Published: July 2006

The acid dissociation constants, Ka, of picric acid and 2,2′,4,4′,6,6′-hexanitrodiphenylamine in acetone, ethyl methyl ketone, and isobutyl methyl ketone were determined in the presence of water. The pKa values increased remarkably with a decrease in the water content. The pKa values in water-free ketones were estimated.
Triplet–Triplet Energy Transfer between the Same Molecular Species
Authors: Masumo Kunio , Ebara Nozomu
Published: July 2006

A method for obtaining the rate constants for triplet–triplet energy transfer between the same molecular species is presented. It is an improvement on a previously proposed method and comprises an analysis of the phosphorescence decay curve of a mixture of an organic substance and its deuterated homolog. It has been found that the new method gives a good fit to experimental decay curves at 77 and 4.2 K. It was also found that the critical transfer distance between similar molecules is usually smaller than that between differrent molecules.
Breathing Vibration of Cyclohexane Ring in Cyclohexanol
Authors: Takeoka Yoshiko
Published: July 2006

It was found that the wave numbers of the bands due to the breathing vibration of the cyclohexane ring in the e-conformer are higher than 802 cm−1 in the monosubstituted cyclohexane-derivatives having substituents Cl, Br, I, SH, SD and SCH3, while lower than 802 cm−1 in cyclohexanol and fluorocyclohexane. The effect of introducing OH group to the cyclohexane ring upon this band was studied.
Electronic Spectra of a Simple Trimethine Cyanine Dye Crystal. (3-Dimethylamino-2-propenylidene)dimethylammonium Perchlorate
Authors: Otsu Masakazu , Tanaka Jiro
Published: July 2006

The electronic spectra of the simplest polymethine cyanine dye crystal were studied by measuring the reflection spectra of (3-dimethylamino-2-propenylidene)dimethylammonium perchlorate. The spectra consist of a single peak situated at 32400 cm−1 in solution. Davydov splitting is observed in the crystal spectra and it is explained by calculating the dipole–dipole interaction energy and the interaction energy between the transition densities with the Ewald sum method.
Reactions of Ozone with 1-(m-Substituted phenylazo)-2-naphthol-6-sulfonic Acids in Aqueous Solutions
Authors: Onari Yasuo
Published: July 2006

The substituent effect on the ozone decoloration reactions of 1-(m-substituted phenylazo)-2-naphthol-6-sulfonic acids (PANSA) in aqueous solutions was investigated. Both the acidities of PANSA and the variation of the ozone decoloration rates of them increased compared to those of the corresponding 1-(m-substituted phenylazo)-2-naphthol-3,6-disulfonic acids (PANDSA). The relationships between the decoloration rates and the indexes(pKOH and σm values) of the basicities of the dyes, however, indicated nearly the same characteristics between the data of these two series of dyes, and the ozone decoloration reactions of PANSA appeared to proceed by nearly the same mechanism as those of PANDSA. The changes of the keto–enol ratios of the dyes with their ozone decolorations suggested that the decoloration rates might rise as the reduction rates of their keto–enol ratios increased. It seems likely that the chief organic product that was finally produced in these reactions is oxalic acid.
Reduction of Aromatic Ketones or Thioketones with Phenylphosphine
Authors: Tamano Michiko , Koketsu Jugo
Published: July 2006

Reactions of certain aromatic ketones or thioketones with phenylphosphine and subsequent addition of diethyl disulfide gave the reduction products of the ketones and S,S-diethyl phenylphosphonodithioate or S,S-diethyl phenylphosphonotrithioate. A possible intermediate of the phosphine moiety was suggested to be phenylphosphinylidene [PhP=O] or phenylphosphinothioylidene [PhP=S]. The reduction of 10,10′-bianthrone and Δ10,10′-bianthrone resulted in the cleavage of the carbon–carbon single and double bonds and the reduction of the carbonyl groups, respectively.
Free Radicals Produced from the Derivatives of Pyrylium Salts in Solution by Photoillumination
Authors: Niizuma Shigeya , Sato Nobuyoshi , Kawata Hiroki , Suzuki Yoshizo , Toda Takashi , Kokubun Hiroshi
Published: July 2006

The photoreactions of 2,4,6-triphenyl- (TPP), 2-t-butyl-4,6-diphenylpyrylium (2BDPP) and 2,4,6-triphenylthiopyrylium (TPTP) salts in tetrahydrofuran (THF) and/or 1,2-dimethoxyethane were investigated. Photoproducts were identified to be pyranyl radicals on the basis of photochemical behavior and ESR spectra. Quantum yields of one-electron reduction reactions of TPP, 2BDPP, and TPTP were obtained to be 0.21, 0.047, and 0.53, respectively. The hf coupling constants of protons in the radicals were determined by simulation. The photoillumination of TPP in THF at low temperatures revealed that a certain intermediate radical species was involved in this one-electron photoreduction.
Kinetics of the Transfer of Picrate Ion at the Water/Nitrobenzene Interface
Authors: Osakai Toshiyuki , Kakutani Tadaaki , Senda Mitsugi
Published: July 2006

Kinetics of the transfer of picrate (Pic−) ion at the interface between an aqueous solution of lithium chloride (LiCl) and a nitrobenzene solution of tetrabutylammonium tetraphenylborate (TBATPB) has been studied by phase-selective a.c. polarography with a two-electrode cell system. By assuming Butler-Volmer type equations for the rate constants, the kinetic parameters of the Pic−-ion transfer have been determined at various concentrations of LiCl (0.02–1.0 mol dm−3) and TBATPB (0.05–0.17 mol dm−3). The rate constants virtually do not change with the electrolyte concentrations. Frumkin correction for the double-layer effect of the rate constants has been examined. The result seems to indicate that the observed potential dependence of the rate constants obtained in moderately concentrated electrolyte solutions may reflect the real potential dependence of the rate constants.
X-Ray Photoelectron Spectra of Halogen-bridged One-dimensional PdII–PdIV Mixed-valence Complexes, [Pd(en)2][PdX2(en)2](ClO4)4
Authors: Yamashita Masahiro , Murase Ichiro , Ikemoto Isao
Published: July 2006

X-Ray photoelectron spectra of [PdII(en)2][PdIVX2(en)2](ClO4)4 (en=ethylenediamine, X=Cl and Br) were measured. The difference in the binding energies of Pd3d between PdII and PdIV in the bromo-bridged complex is smaller than that in the chloro-bridged complex. This result is consistent with those of the crystal structures, electrical conductivities, and electronic spectra previously reported.
Reaction Volume for the OH− Addition to Hexafluoroacetylacetonate Ligand on CoIII Complex
Authors: Kitamura Yoichi
Published: July 2006

For the title reaction in water: L4Co(hfac)z+OH−=L4Co(hfacOH)z−1, reaction volumes (ΔV°) at infinite dilution were obtained at 25 °C, where A4 is (NH3)4, (en)2, α-trien, β-trien, f(N)-i-dtma, α-edda, β-edda, and Hhfac stands for hexafluoroacetylacetone. The resulting ΔV° values supported the addition of OH− to CoA4(hfac)z.
A Raman Study of Aqueous KOH Solution in Glassy State
Authors: Kanno Hitoshi , Hiraishi Jiro
Published: July 2006

Raman spectra of an aqueous KOH solution were measured in the OH stretching region and in the low frequency region (<700 cm−1). Contrary to the results reported by Sharma and Kashyap, only one Raman band specific to an aqueous KOH solution was observed at ≈285 cm−1 in the low frequency Raman spectrum.
Reaction of Carbon Dioxide with 1-Phenylaziridine Catalyzed by Organo-antimony and -tin Compounds
Authors: Matsuda Haruo , Ninagawa Akira , Hasegawa Hiroshi
Published: July 2006

The reactions of carbon dioxide(CO2) with 1-phenylaziridine(1) to afford 3-phenyl-2-oxazolidone(2) were carried out in the presence of organo-antimony and -tin compounds as catalysts. Tetraphenylstibonium bromide(Ph4SbBr) and triphenyltin bromide(Ph3SnBr) were found to be active catalysts. The use of a polar aprotic solvent, such as a HMPA, provided optimal reaction conditions.
Synthetic Photochemistry. XXXII. Structures of By-products Formed in the Photocycloaddition of Myrcene to Methyl 2,4-Dioxoalkanoates
Authors: Takeshita Hitoshi , Komiyama Kei , Okaishi Koya
Published: July 2006

Structures of the by-products formed in the photocycloaddition of myrcene to methyl 2,4-dioxohexanoate and 2,4-dioxopentanoate were elucidated. They were shown to be formed by a 1,5-hydrogen shift of the intermediate (2+2)π adducts of conjugated dienes.
The Magnetic Properties of the Copper(II) Complexes with ω-Amino Carboxylic Acids
Authors: Emori Shuji , Noguchi Toshihiko , Muto Yoneichiro
Published: July 2006

Compounds of formula CuX2(OOC(CH2)mNH3)2·nH2O (m=2–5 and X=Cl or Br) and CuX3⁄2 (OOCCH2NH3) (X=Cl or Br) have been prepared and characterized by means of magnetic susceptibility and IR spectroscopy measurements. The correlation of their magnetic moments with the pKa values of their parent carboxylic acids is discussed.
CIDEP Study of 1,4-Naphthosemiquinone in Alcohols
Authors: Niizuma Shigeya , Sato Nobuyoshi , Kawata Hiroki , Murakami Osamu , Kanemoto Akihiko , Kokubun Hiroshi
Published: July 2006

A Chemically Induced Dynamic Electron Polarization (CIDEP) signal of 1,4-naphthosemiquinone (NQH·) was examined by intermittent-light irradiation to a system of 1,4-naphthoquinone (NQ) and phenol (PhOH) in toluene–2-propanol (2:3), toluene–ethanol (2:3), and neat 2-propanol. The enhancement factors of the initial polarization and the F-pair polarization of the systems were determined separately. From the unusual pattern of a time profile of the ESR signal with a CIDEP phenomenon observed on the photoirradiated NQ–PhOH system in ethanol, it is concluded that in ethanol the photoexcited NQ first abstracts a hydrogen to give NQH· then NQH· releases a proton to form NQ\ewdot.