bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient Synthesis and Structure of Bis[acetonitrile(11,13-dimethyl-1,4,7,10-tetraaza-10,13-cyclotridecadien-12-ylidene)nickel(II)] Perchlorate
Authors: Mochizuki Katsura , Toriumi Koshiro , Ito Tasuku
Published: July 2006

The titled binuclear nickel(II) complex has been synthesized by the oxidation of 11,13-dimethyl-1,4,7,10-tetraaza-10,13-cyclotridecadienatonickel(II) perchlorate with iron(III) perchlorate in deoxygenated CH3CN in ca. 70% yield and its structure has been determined.
Photoreductive Dehalogenation of Organic Halides in the Presence of Lithium Aluminum Hydride
Authors: Shimizu Nobujiro , Watanabe Kenji , Tsuno Yuho
Published: July 2006

Lithium aluminum hydride markedly accelerates photoreductive dehalogenation of cyclopropyl, aromatic, and olefinic halides carried out in ether.
Restricted Rotation Involving the Tetrahedral Carbon. LII. Rotational Barriers in 1,2,3,4-Tetrafluoro- and 1,4-Dimethoxy-9-(1-cyano-1-methylethyl)triptycenes
Authors: Yamamoto Gaku , Tanaka Akira , Suzuki Masahiko , Morita Yasuji , Oki Michinori
Published: July 2006

Kinetic measurements of rotamer isomerization of the title compounds show that the rotational barriers in these compounds are considerably higher than those in the peri-unsubstituted and the peri-chloro or peri-methyl compounds, affording a support to our earlier finding that the rotational barrier increases and then decreases as the peri-substituent becomes bulkier in 9-t-alkyltriptycenes.
Regioselective Hydrogenation of Unsymmetrically Substituted Cyclic Anhydrides Catalyzed by Ruthenium Complexes with Phosphine Ligands
Authors: Ikariya Takao , Osakada Kohtaro , Ishii Youichi , Osawa Shoichi , Saburi Masahiko , Yoshikawa Sadao
Published: July 2006

Regioselective hydrogenation of unsymmetrically substituted cyclic anhydrides catalyzed by ruthenium complexes with mono-, di-, or triphosphine ligands produced the corresponding two isomeric lactones, where the regioselectivity was influenced by the bulkiness of the substituent(s) on the anhydrides and of the phosphine ligands of catalyst.
Conformation et Configuration en Solution d’une Serie d’Oxo Aldoximes Aliphatiques
Authors: Bernadou Jean , Fayet Jean Pierre , Bonnafous Monique , Mauret Pierre
Published: July 2006

La stéréochimie de cinq α-oxo aldoximes R–CO–CH (NOH) (R=Me 1, Et 2, n-Pr 3, i-Pr 4, t-Bu 5) a été étudiée : la configuration connue est E dans tous les cas mais les deux conforméres s-cis et s-trans peuvent exister en différentes proportions lorsque varient la taille de R, la température ou le pH.
Chemical-state Analysis by Means of Soft X-Ray Spectroscopy. I. L2,3-Emission Spectra for Phosphorus, Sulfur, and Chlorine in Various Compounds
Authors: Taniguchi Kazuo
Published: July 2006

The phosphorus-, sulfur-, and chlorine-L2,3 emission spectra in various compounds are obtained using secondary excitation. The spectra are discussed from the point of view of chemical-state analysis. It should be noted that the spectra of a highly ionic bond reveal scarcely no influence of the cations. However, the spectra with a covalent character are complex as a result of the molecular orbital generated with the covalent bond. The spectral features are influenced by the chemical condition of the surrounding atoms and are sensitive to oxygen and hydrogen.
Chemical-state Analysis by Means of Soft X-Ray Spectroscopy. III. O Kα Emission Spectra for Oxyanions in Different Salts
Authors: Taniguchi Kazuo
Published: July 2006

The oxygen Kα spectra of the oxyanions in different salts are obtained by secondary excitation. The obtained spectra are affected by the cations, the central atom, and the chemical-bond condition. Generally, there are four components in the spectra, but one small component may originate from the anomalous reflection of an analyzing crystal. The spectra are discussed from the point of view of chemical-state analysis.
Determination of Formal Potentials of Multihemoprotein, Cytochrome c3 by 1H Nuclear Magnetic Resonance
Authors: Kimura Keisaku , Nakajima Shinsuke , Niki Katsumi , Inokuchi Hiroo
Published: July 2006

Macroscopic redox potentials of tetrahemoprotein, cytochrome c3 from D. vulgaris, Miyazaki strain, were derived from 400 MHz 1H NMR measurements. The formal potential, E1o′, was determined to be −0.245±0.005 V vs. NHE compared with a value of −0.240 V obtained electrochemically. The distributions of the intermediate states from the NMR spectra during a redox titration are in good agreement with those previously determined by electrochemistry.
Comparative Studies of Anionic Molecular Assemblies as Mediums for Electron Transfer Quenching of Excited Ru[(bpy)3]2+ by Cationic Quenchers
Authors: Shioyama Hiroshi , Takami Akihiro , Mataga Noboru
Published: July 2006

Behaviors of excited [Ru(bpy)3]2+ bound to anionic molecular assemblies such as polymer electrolytes, vesicles and micelles together with electron-acceptor quencher MV2+ have been investigated by measurements of [Ru(bpy)3]2+ luminescence quenching and radical yields in electron-transfer quenching using a dye laser photolysis apparatus. Quenching behavior characteristic to each molecular assembly has been observed. A remarkable enhancement of quenching was observed in the presence of poly(vinyl sulfate). Such an effect was observed also in sodium dihexadecyl phosphate solution though it is less pronounced. However, no such specific quenching behavior was observed in sodium dodecyl sulfate micellar solution.
Formation Constants of Cyclodextrin Inclusion Complexes with Iodine in Aqueous Solutions
Authors: Sanemasa Isao , Kobayashi Toyohisa , Deguchi Toshio
Published: July 2006

Formation constants of cyclodextrin (CyD) inclusion complexes with iodine were determined by measuring solubilities of iodine vapor in water. The formation constants at 25 °C are 8.3×103 (α-CyD), 1.0×102 (β-CyD), and 13 dm3 mol−1 (γ-CyD). The temperature dependence of α-CyD–I2 complexation was studied. ΔH and ΔS, being 9.52 kJ mol−1 and 107 J K−1 mol−1 at 25 °C, respectively, are both largely dependent on temperature even within a rather small temperature range 15–35 °C studied. For the complexation with α-CyD, contribution of dehydration of iodine was estimated. The method proposed here is useful to study the formation of CyD association complexes with such substrates as are slightly soluble in water and easily vaporize from the aqueous phase.
Solubility and Synergistic Extraction Equilibria for [4-(2-Pyridylazo)resorcinolato] Nickel(II) Complexes
Authors: Hoshino Hitoshi , Yotsuyanagi Takao
Published: July 2006

The nickel(II) complex of 4-(2-pyridylazo)resorcinol (PAR, H2L) is known to show somewhat anomalous and complicated behavior in solution. In this regard, the solubility and the synergistic extraction equilibria of the above complex are studied in connection with acid dissociation reactions. The intrinsic solubility and the acid dissociation constants are determined to be, S0=[[Ni(HL)2]]=10−6.2±0.1 mol dm−3, Ka1=[[Ni(HL)L]−][H+][[Ni(HL)2]]−1=10−6.2±0.1, and Ka2=[[NiL2]2−][H+][[Ni(HL)L]−]−1=10−7.1×0.1, respeactively in the solution with the ionic strength of 0.10 (Na2SO4) at 298 K. Using the above constants, the extraction constant of the neutral complex with trioctylphosphine oxide (TOPO) into chloroform is evaluated as Kex=[[Ni(HL)2(TOPO)2]]o[[Ni(HL)2]]−1[TOPO]o−2=103.1±0.2, where the subscript o denotes the organic phase. An equilibrium diagram for the nickel(II)–PAR complexes is proposed.
Synthesis and Properties of a New Photoresponsive Crown Ether with a Fluorescent Stilbene-cap
Authors: Shinkai Seiji , Miyazaki Kiminori , Nakashima Mikio , Manabe Osamu
Published: July 2006

A new photoresponsive crown ether 2 with a stilbene-cap was synthesized. The crown trans-2 could extract Li+ and Na+ into the organic phase, and UV light irradiation which produces photoisomerized cis-2 enhanced the extractability. Thus, the stilbene-cap induces the conformational change in the crown ether moiety by photoirradiation.
Sterically Controlled Synthesis of Aspartic Acid by Addition of Dialkyl Malonate to N-Benzyloxycarbonyl-l-alanyl-2-chloroglycine Methyl Ester
Authors: Shiono Shozo , Harada Kaoru
Published: July 2006

Aspartic acid was synthesized stereoselectively by addition of dialkyl malonate to N-benzyloxycarbonyl-l-alanyl-2-chloroglycine methyl ester, followed by hydrolysis. Substituent effect of the alkyl group of dialkyl malonate on the stereoselectivity was observed. Higher optical purity of aspartic acid was obtained as the alkyl group of dialkyl malonate became bulkier.
Preparation and Conversion of Aminodiphenylcyclopropenium Salts to 1,2,3-Triazines
Authors: Yoshida Hiroshi , Yagi Kohnosuke , Tamai Tomoji , Sano Hiroe , Ogata Tsuyoshi , Matsumoto Kiyoshi
Published: July 2006

Diphenylcyclopropenone gave aminodiphenylcyclopropenium fluorosulfate (3) by ethylation with ethyl fluorosulfate, followed by treating with secondary amine in one-pot operation. The salt 3 reacted with sodium azide to afford 1,2,3-triazine in a good yield.
Palladium Catalyzed Coupling Reaction of α-Bromo Ketones with Hexabutylditin
Authors: Kosugi Masanori , Koshiba Mamoru , Sano Hiroshi , Migita Toshihiko
Published: July 2006

Palladium-catalyzed reaction of α-bromo ketones with hexabutylditin in the presence of trimethylsilyl chloride gave enol trimethylsilyl ether in moderate to good yields.
The Determination of a Small Amount of Biological Constituent by the Use of Chemiluminescence. IV. A Highly Sensitive Detector for the HPLC of Protein
Authors: Hara Tadashi , Toriyama Motohiro , Ebuchi Takashi
Published: July 2006

A highly sensitive detector for the HPLC of protein has been manufactured by making use of the phenomenon that the catalytic activity of copper(II) against the chemiluminescence between luminol and hydrogen peroxide is lowered in the presence of protein. According to the present detector, 2×10−4–1×10−1 g/dm3 protein could be determined, with the detection limit of 10 ng. By combining the present detector with a TSK-GEL G3000SW column, 2×10−3–1×10−1 g/dm3 ovalbumin could be determined, with the detection limit of 50 ng. The ovalbumin in 2×10−2 g/dm3 could be determined by the internal-standard method with a coefficient of variation of 8.65% (n=5). Care had to be taken in the detection of the protein acting as a chemiluminescent catalyst.
Synthetic Inorganic Ion-exchange Materials. XXXVIII. Acid-base Properties of a Cryptomelane-type Hydrous Manganese(IV) Oxide and Some Chromatographic Applications
Authors: Tsuji Masamichi , Abe Mitsuo
Published: July 2006

The pH titration curves of a cryptomelane-type hydrous manganese(IV) oxide(CRYMO) apparently showed a dibasic Brönsted-acid towards Li+, Na+, K+, and Rb+ ions and a monobasic Brönsted-acid towards Cs+ ions, instead of an amphoteric character, using a mixed solution of alkali metal nitrate and nitric acid or each hydroxide with the ionic strength of 0.1. The apparent ion-exchange capacities(meq/g) of alkali metal ions increased in this order: Li+(0.50)<Na+(0.55)<Cs+(0.85)<Rb+(1.00)<K+(1.10) at pH 2 and Cs+(1.20)<Rb+(1.72)<Na+(1.78)<Li+(1.80)<K+(1.81) at pH 10. The point of zero charge(PZC) of CRYMO was estimated to be much lower than 2. The unusual selectivity for K+ and Rb+ ions can be successfully applied to some ion-exchange separations: e.g., the removal of K+ ions from NaNO3 and NaMnO4 solutions, the removal of Rb+ ions from a CsNO3 solution, and the selective uptake of K+ ions from seawater.
Atomic Absorption Spectrophotometric Determination of Copper(I) After Extraction of Its Ternary Complex with 3-(4-Phenyl-2-pyridyl)-5,6-diphenyl-1,2,4-triazine and Tetraphenylborate into Molten Naphthalene
Authors: Nagahiro Tohru , Uesugi Katsuya , Satake Masatada , Puri Bal K
Published: July 2006

A preferable atomic absorption spectrophotometric method has been established for trace determination of copper(I) via extraction of its ion-associated complex with 3-(4-phenyl-2-pyridyl)-5,6-diphenyl-1,2,4-triazine and tetraphenylborate into molten naphthalene. The optimum pH range for the extraction is 1.6–8.2. Solid naphthalene containing the copper(I) complex is separated by filtration and dissolved in N,N-dimethylformamide. The absorbance is measured at 324.7 nm. Beer’s law is obeyed in the concentration range 2.5–80 μg of copper in 10 cm3  N,N-dimethylformamide solution. Ten repeat analyses on a sample containing 35 μg of copper give a mean absorbance of 0.205 with a standard deviation of 0.0017 and a relative standard deviation of 0.83%. The method has been successfully applied to determination of copper in standard reference materials and biological samples.
Preparation and Some Properties of Bis(trimethylenediamine)cobalt(III) Complexes with a Bidentate-N,S or -N,Se Ligand
Authors: Konno Takumi , Okamoto Ken-ichi , Einaga Hisahiko , Hidaka Jinsai
Published: July 2006

Seven optically active cobalt(III) complexes of [Co(bidentate-N,S or -N,Se)(tn)2] type were prepared for the first time; bidentate-N,S or -N,Se denotes 2-aminoethanethiolato (aet), 2-aminoethaneselenolato (aes), 2-aminoethanesulfenato (aese), 2-aminoethanesulfinato (aesi), 2-(methylthio)ethylamine (mea), and 2-(methyl-seleno)ethylamine (mseea). These complexes were characterized from their absorption, CD, and 1H NMR spectra. All complexes obtained were assigned to the Λ configuration. The (+)550CD mea isomer took selectively the Λ-(R) configuration in solution, while the (+)550CD mseea isomer a mixture of the Λ-(R) and Λ-(S) ones. The absorption and CD spectra of the complexes are discussed in comparison with those of the corresponding bis(ethylenediamine)cobalt(III) complexes. The Λ-(R)- and Λ-(S)-[Co(aese)(tn)2]2+ isomers showed the CD spectral change with time and it was suggested that the epimerization at sulfur was accompanied by the racemization of the skew pair of chelate rings.
Flavin Mononucleotide Chemiluminescence for Determination of Traces of Copper(II) by Continuous Flow and Flow Injection Methods
Authors: Yamada Masaaki , Kanai Hideshi , Suzuki Shigetaka
Published: July 2006

Flow injection analysis, with chemiluminescence detection, is used to determine traces of copper(II) by means of the flavin mononucleotide–hydrogen peroxide–phosphate buffer system. This permits the determination of copper(II) more selectively than any other chemiluminescence system with a detection limit of 0.03 ng(20-μl sample injection) or 0.06 ng ml−1 (continuous sample flow). The linear range is 3 orders of magnitude, the sampling rate is 120 h−1, and the relative standard deviation is 3.1% for 1 ng Cu(II)(n=10). Iron(II) and chromium(III and VI), the strongest enhancer after copper(II), provide signals 2–3% of that for copper(II). Effect of surfactant micelles on the signal for copper is also discussed. The method is successfully applied to real samples.
Synthesis of O-β-d-Glucopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→6)-d-glucopyranose; Dehydrative β-d-Glucosylation Using 2-O-Acetyl-3,4,6-tri-O-benzyl-d-glucopyranose
Authors: Koto Shinkiti , Morishima Naohiko , Sato Hiroko , Sato Yuko , Zen Shonosuke
Published: July 2006

A step-by-step synthesis of O-β-d-glucopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→6)-d-glucopyranose through the dehydrative β-d-glucosylation using 2-O-acetyl-3,4,6-tri-O-benzyl-d-glucopyranose and the ternary system of p-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, and triethylamine is described.
Copper(II)-Catalyzed Transamination between Pyruvate and Hydrophobic Pyridoxamine Embedded in Synthetic Bilayer Membranes
Authors: Murakami Yukito , Kikuchi Jun-ichi , Akiyoshi Kazunari
Published: July 2006

The copper(II)-catalyzed transamination of 4-aminomethyl-5-[(dihexadecylamino)methyl]-2-methyl-3-pyridinol [(PM)2C16] with sodium pyruvate was investigated in an aqueous medium at pH 6.9, μ 0.10 (KCl), and 30.0±0.1 °C in the presence of single-walled bilayer vesicles of N,N-dihexadecyl-Nα-[6-(trimethylammonio)hexanoyl]-l-alaninamide bromide [N+C5Ala2C16] and N,N-dihexadecyl-Nα-[6-(trimethylammonio)hexanoyl]-l-histidinamide bromide [N+C5His2C16]. The binding mode of the pyridoxamine moiety in the vesicles was clarified by comparing the reaction behavior of the (PM)2C16–pyruvate–CuII system with that of the 4-aminomethyl-5-dodecylthiomethyl-2-methyl-3-pyridinol [(PM)C12]–pyruvate–CuII system. The pyridoxamine moiety of (PM)2C16 was more tightly anchored in the hydrogen-belt domain of the membranes than that of (PM)C12 as confirmed by fluorescence polarization spectroscopy. The difference in binding mode between (PM)2C16 and (PM)C12 is reflected on the copper(II)-coordination equilibria for the formation of the copper(II)–ketimine intermediates. The copper(II)-catalyzed transamination of (PM)2C16 with pyruvate in the N+C5His2C16 vesicle was most enhanced among related reaction systems treated here. The rate enhancement was attributed to the favorable formation of the reactive 2:1 ketimine–copper(II) chelate and the general-base catalysis by the coordination-free imidazolyl group of the lipid.
Phase Transition Behavior and Membrane Structure of Monoalkyl Amphiphiles
Authors: Kumano Atsushi , Kajiyama Tisato , Takayanagi Motowo , Kunitake Toyoki , Okahata Yoshio
Published: July 2006

Membrane structure and crystal-liquid crystal phase transition behaviors were investigated for two kinds of artificial amphiphiles with single alkyl chain and N-benzylideneaniline moiety. These artificial amphiphiles showed both thermotropic and lyotropic mesomorphisms in a similar manner to biological lipids. Artificial amphiphile with one polar head group formed the multilayer liposome even in a low concentration region of amphiphile/water system. Artificial amphiphile with two polar head groups at both ends of the molecule does not form the multilayer liposome but forms monomolecular lamellae. Addition of cholesterol to the two polar-headed amphiphile changed its aggregated structure drastically from monomolecular lamellae to large single liposomes composed of monomolecular layer. In the case of two polar-headed amphiphile/water system, two endothermic peaks were observed, which were assigned to gel I to gel II and gel II to mesophase transitions. These transitions may correspond to meltings of partial and whole part of hydrophobic portion in amphiphilic molecule, respectively.
Conformation Analyses of Poly(l-lysine) Induced by Various Surfactants
Authors: Takeda Kunio
Published: July 2006

The relative proportion of α-helix, β, and random-coil structures in each conformation of poly(l-lysine) (PLL) caused by surfactants was computed by simulating a mixed spectrum of typical circular dichroism(CD) spectra for these structures to the experimentally obtained spectrum. Simulation was done in both the 190–250 nm and 200–250 nm regions at 1-nm intervals. The results show that PLL assumed 52 and 75% α-helix (at largest) in sodium octyl sulfate (SOS) and sodium 1-octanesulfonate solutions, respectively. The α-helical structure was found to coexist with considerable amounts of β and random-coil structures in these surfactant solutions. For instance, 51% α-helical structure coexisted with 29% β-structure and 20% random-coil structure in 6.0 mmol dm−3 SOS. In contrast, PLL did not assume any α-helical structure in the concentration range of 0 to 10 mmol dm−3 sodium dodecyl sulfate(SDS). Rather, the random-coil structure was transformed to a β-structure when SDS was added to PLL. The effects of NaCl and of 1-octanol on the relative proportions of the three structures in PLL were also examined.
Structure Model for Liquid Carbon Tetrachloride
Authors: Nishikawa Keiko , Iijima Takao
Published: July 2006

The X-ray scattering intensity for the visualized structure model of a liquid is formulated. It is ascertained that by the bcc model for liquid carbon tetrachloride the experimental intensity has been simulated well.
The Arrhenius Parameters for the Reactions of O Atoms with Ethene and Five Fluoroethenes
Authors: Umemoto Hironobu , Sugiyama Koichiro , Tsunashima Shigeru , Sato Shin
Published: July 2006

The rate constants for the reactions of ground-state oxygen atoms with ethene and five fluoroethenes have been measured over the temperature range of 240–450 K, using a pulse radiolysis-resonance absorption technique. The rate constants were well expressed by the following Arrhenius expressions: k(O+C2H4)=8.4×106 exp(−712⁄T); k(O+C2H3F)=3.1×106 exp(−622⁄T); k(O+CH2=CF2)=2.4×106 exp(−638⁄T); k(O+cis-CHF=CHF)=1.9×106 exp(−500⁄T); k(O+C2HF3)=3.0×106 exp(−544⁄T); k(O+C2F4)=8.1×106 exp(−634⁄T), in units of m3mol−1 s−1. The change in the preexponential factors with the degree of fluorination is discussed in terms of the conventional transition-state theory.
Photocatalytic Oxidation of Sulfur on the Doped TiO2 Catalysts
Authors: Matsumoto Yasumichi , Yamaguchi Yasuhide , Sato Ei-ichi
Published: July 2006

TiO2(anatase) doped with various elements was used as the photocatalyst in the production of sulfuric acid from sulfur in water into which O2 was bubbled. The catalysts doped with typical elements having one and two valencies showed high catalytic activity, but some doped with typical elements having four and five valencies showed low activity. The intermediate, i.e., \dotO2H radical, in the O2 reduction produced by photoproduced electrons will probably play an important part in the production of sulfuric acid. Therefore, it was suggested that the Ti3+ ion in the TiO2 lattice which contribute to direct O2 reduction will inhibit sulfuric acid production. In the case of transition metal dopants, the transition metal cation in the TiO2 lattice will directly affect the O2 reduction. The catalyst doped (deposited) with Pt shows the highest catalytic activity of all the catalysts used in the present study.
Environment Effects on the ESR Spectrum of the Cation Radical of Dimethylketene in Low Temperature Matrices
Authors: Fujisawa Jun , Sato Shin , Shimokoshi Kazuo , Shida Tadamasa
Published: July 2006

The cation radical of dimethylketene produced in γ-irradiated solid solutions of various halocarbons has been investigated by ESR over a temperature range from 77 K to the melting point of each matrix. The cation radical in CCl4 was stable up to about 180 K and the spectrum was well resolved to allow the determinations of the anisotropic ESR parameters. In CCl2FCClF2 and CCl2FCCl2F, a series of irreversible spectral changes was observed with an increase in temperature. This process was interpreted in terms of the formation of the dimer cation. In the matrix of CCl3F, the ESR spectrum exhibited extra structure, which varied reversibly with temperature. The analyses of the spectra suggested that the cation radical in CCl3F weakly interacts with surrounding matrix molecules to form adducts.
A Sudden-polarization Model to Predict Excited State Reactivity of β-t-Butylstyrene
Authors: Kikuchi Osamu , Yoshida Hideki
Published: July 2006

A model in which two zwitteriorts play a significant role was employed to account for solvent and substituent effects on photochemical reactions of β-t-butylstyrene. These zwitterions are formed by 90° rotation about the external C=C double bond. Semi-empirical MINDO/3 calculations showed that these zwitterions can be two channels which give the observed reacation products. The model also elucidated satisfactorily the photochemical reactions of para substituted β-t-butylstyrenes.
Redox Behavior of N,N′-Ethylenebis(salicylideneaminato)bis(triphenylphosphine)ruthenium(II)
Authors: Doine Hideo , Stephens Francis F , Cannon Roderick D
Published: July 2006

Visible spectra and electrochemical behavior of the title complex [Ru{C2H4(N=CHC6H4O-o)2}{P(C6H5)3}2] (I) are reported. The redox potentials of the ruthenium complex were determined at 25°C to be E\ominus=0.27±0.01 V (in CH2Cl2) and −0.161±0.005 V (in CH3OH), relative to E\ominus(Fe(C5H5)2)+⁄0)=0.400 V.
The Ullmann Coupling Reaction of Axially Chiral (S)-2,2′-Bis(1-iodo-2-naphthyloxycarbonyl)-1,1′-binaphthyl
Authors: Miyano Sotaro , Shimizu Kunitoshi , Sato Shinya , Hashimoto Harukichi
Published: July 2006

The intramolecular Ullmann coupling of the title diester proceeded in low yield but with virtually complete asymmetric induction in joining the two naphthyl units leading to the 12-membered cyclic diester of (S,S)-configuration, which is the same diastereomer obtained from the reaction of (S)-2,2′-bis(1-bromo-2-naphthoyloxy)-1,1′-binaphthyl.
Electrogenerated Acid as an Efficient Catalyst for the Protection and Deprotection of Alcohols with Dihydropyran and Transesterification of Glyceride
Authors: Torii Sigeru , Inokuchi Tsutomu , Kondo Kazumi , Ito Hiroshi
Published: July 2006

Protection of alcohols with 3,4-dihydro-2H-pyran and hydrolysis of the resulting tetrahydropyranyl ethers are cleanly performed by using an electrogenerated acid (EG acid) as a catalyst. Transesterification of glyceride was also achieved with EG acid.
Synthesis of Licoisoflavone A and Related Compounds
Authors: Tsukayama Masao , Fujimoto Kunihiro , Horie Tokunaru , Masumura Mitsuo , Nakayama Mitsuru
Published: July 2006

2′,4′,5,7-Tetrahydroxyisoflavone was partially benzoylated with benzoyl chloride to give 7-benzoyloxy-2′, 4′,5-trihydroxyisoflavone. The condensation of the 7-(benzoyloxy)isoflavone with 2-methyl-3-buten-2-ol, followed by the hydrolysis of the resultant 3′-(3-methyl-2-butenyl)isoflavone gave licoisoflavone A. Its 5′-(3-methyl-2-butenyl) isomer was also synthesized from 5-benzoyloxy-2′,4′,7-trihydroxyisoflavone in a similar manner.
Characterization of α- and β-Dodecamolybdophosphate Complexes Formed in Aqueous Solutions Including Acetonitrile, Acetone, or Dioxane
Authors: Hori Toshitaka , Fujinaga Taitiro
Published: July 2006

On the basis of a spontaneous conversion reaction of molybdophosphate (formed in an aqueous medium including acetonitrile, acetone, or dioxane), the existence of β-modification of dodecamolybdophosphate has been substantiated. The conversion reaction was highly affected by the presence of the organic solvents. In the absence and/or the presence of the organic solvent of less than 20% by volume, the reaction proceeded instantaneously and, in consequence, β-modification practically did not exist, but α-modification existed entirely. Whereas, in the presence of the organic solvent ranging from 30 to 60%, β-modification was so stable, it could be observed for a fairly long duration. However, it was still thermodynamically unstable and finally converted to α-modification at a certain rate depending on the concentration of the organic solvent. With more of the organic solvent than 65%, the formation of β-modification and thence α-modification, were prohibited. As a result of these facts, α- and β-modifications were individually prepared in solutions consisting of 0.05 M Mo(VI)/1.2 M HCl/40% acetonitrile. On each modification thus formed, a chemical reduction (with such metals as nickel, iron, or lead) and solvent-extraction isolation (using chloroform as an auxiliary solvent) were performed. The inherent absorption spectra of the two modifications were clearly distinguished in both oxidized yellow and reduced blue forms. The utility of β-modification in a sensitive spectrophotometric determination of phosphate ion was also discussed.
Bilirubin in Aqueous Solution. Absorption Spectrum, Aqueous Solubility, and Dissociation Constants
Authors: Moroi Yoshikiyo , Matuura Ryohei , Hisadome Tetsuo
Published: July 2006

This report analyzes the change of both spectrum and solubility of bilirubin with pH in buffer solutions. Bilirubin (AH2) is a dibasic acid which dissociates by two steps (AH2\oversetK1\ightleftharpoonsAH1\oversetK2\ightleftharpoonsA) with increasing pH; the wavelengths at the resulting three isosbestic points are 457 nm (AH2 and AH1), 485 nm (AH1 and A), and 472 nm (A and AH2). The solubility increases with increasing pH, where the total concentration ([AH2]+[AH1]+[A]) changes subject to a second-order curve of 1/aH+. From the spectral change and the three coefficients of the solubility curve, K1 and K2 values were estimated to be (6.7±2.6)×10−7 and (3.4±1.0)×10−8, respectively. These dissociation constants are much smaller than those of aliphatic carboxylic groups, and the reason for it was discussed together with the values already reported and their reliability.
Preparation and Some Reactions of Diarylgermylenedialkali Metals
Authors: Mochida Kunio , Matsushige Naoki , Hamashima Mari
Published: July 2006

The reactions of diarylgermanes with alkali metals in HMPA/THF or THF were found to give the corresponding diarylgermylenedialkali metals in high yields. Diphenylgermylenedipotassium reacted with aryl halides or carbonyl compounds to give reduction products predominantly. With alkyl halides, diphenylgermylenedipotassium gave mainly substitution products.
Synthesis Utilizing Reducing Ability of Carbon Monoxide. New Methods for Synthesis of N-Substituted Selenoamides
Authors: Ogawa Akiya , Miyake Jun-ichi , Kambe Nobuaki , Murai Shinji , Sonoda Noboru
Published: July 2006

Convenient one-pot syntheses of N-substituted selenoamides (2) from nitriles, metallic selenium, carbon monoxide, water, and amines have been developed on the basis of an amino-group-exchange reaction of in situ formed N-unsubstituted selenoamides (1) with primary or secondary amines. The reactions consist of two processes, i.e., the formation of selenoamides 1 by the reaction of nitriles and H2Se formed from selenium, carbon monoxide and water, and the subsequent amino-group-exchange reaction of 1 with aliphatic amines. The obtained 2 are generally stable enough to be kept for several weeks under the atmosphere of nitrogen at 0 °C without any appreciable degradation. In the cases of primary amines, the corresponding selenoamides were also obtained from nitriles, selenium, carbon monoxide, and primary amines by a single-step mixing at the beginning of the reaction.
Synthetic Studies on Germacranolides. Synthesis of Optically Active 3-Oxygenated 13-Norheliangolides
Authors: Kuroda Chiaki , Nakamura Takayoshi , Hirota Hiroshi , Enomoto Katsumi , Takahashi Takeyoshi
Published: July 2006

(3R,6S,7S,1(10)E,4Z)- and (3R,6S,7S,1(10)E,4Z)-3-Methoxymethoxy-13-nor-1(10),4-germacradieno-12,6-lactones were synthesized from (−)-carvone, utilizing anionic oxy-Cope rearrangement to construct a ten-membered ring compound.
The Identification of the Compositions of the Compounds Formed in an Addition Reaction Involving Insoluble Substances
Authors: Hihara Goro , Shimizu Tadashi , Miyamae Hiroshi , Nagata Miharu
Published: July 2006

A method has been developed for the identification of the compositions of all the insoluble compounds which are formed in the reaction of an insoluble substance (A) with a soluble one (B). It consists of allowing a fixed amount of A to react with various amounts of B in a fixed volume of a solution, determining the concentrations of B(=[B]) remaining unreacted after the equilibrium is reached, and then finding the number of the formed compounds and their compositions from the variations in [B] on the basis of the phase rule. This method was applied to the reactions of PbI2 with diethylenetriamine (dien) and with 1,3-propanediamine (pren); the presence of the following addition compounds was found: PbI2·Y(dien) (Y=1⁄2 and 1) and PbI2·Y(pren) (Y=4⁄5, 1, and 2).
Bivalent Cobalt Complexes with 1-(2-Pyridylazo)-2-naphthol and Analogous Ligands
Authors: Mochizuki Katsura , Fujimoto Masatoshi
Published: July 2006

Bivalent cobalt complexes with the title ligands were synthesized, isolated, and characterized by absorption spectra and magnetic moments. It has been suggested that the cobalt(II) complexes have more flexible structures than the corresponding cobalt(III) complexes. The cobalt(II) complexes were found to be oxidized to the cobalt(III) complexes in DMSO in the presence of copper(II) ions. Cyclic voltammetry elucidated the reversible CoII/CoIII couples of the cobalt complexes in acetonitrile. The values of E1⁄2 for the CoII/CoIII couples were found to depend on the coordinating ligands. The relation between E1⁄2 and pKa of the ortho-hydroxyl group in the ligands was discussed.
Recovery of Heavy Metals with Calcium Silicon Alloy. IV. Stoichiometric Discussion of the Reduction of Lead(II), Nickel(II), Iron(III), and Mercury(II) Ions
Authors: Tokunaga Shuzo
Published: July 2006

The reduction of Pb2+ and Ni2+ ions to the metallic state with the Ca–Si alloy powder can be stoichiometrically interpreted by the following elementary reactions 1–4 including the decomposition of water, a side reaction:

d Ca0+Me2+=Ca2++Me0(1)

(Ca0+2Me2+=Ca2++2Mez−1)(1′)

Si0+2Me2++3H2O=H2SiO3+2Me0+4H+(2)

(Si0+4Mez++3H2O=H2SiO3+4Mez−1+4H+)(2′)

Ca0+2H2O=Ca2++H2+2OH−(3)

Si0+3H2O=H2SiO3+2H2(4)

The occurrence of a reaction other than the above ones was suggested for the reduction of Fe3+ to Fe2+ ion under strongly acidic conditions. The reduction of Pb2+ and Ni2+ ions proceeded very slowly. On viewing the equivalents oxidized, the contribution of Ca in the alloy to the overall reaction was greater than that of Si; Si scarcely participated at all in the reduction of Fe3+ ion. Based on the above elementary reactions, the reduction of Hg2+ ion was discussed stoichiometrically. Almost the same equivalents of Hg0 and HgI species formed in a 20-matom dm−3 Hg2+ solution, with an initial pH of 4.0. The contribution of Si to the reaction was greater than that of Ca.
Fe K-Edge XANES and EXAFS of the X-Ray Absorption Spectra of FeCl3 Aqueous Solutions. A Structural Study of the Solute, Iron(III) Chloro Complexes
Authors: Asakura Kiyotaka , Nomura Masaharu , Kuroda Haruo
Published: July 2006

The Fe K-edge spectra were measured on FeCl3 aqueous solutions by use of synchrotron radiation to reveal the solute structure from the analysis of Fe K-edge EXAFS and XANES. It is concluded that the solute exists mainly as [Fe(H2O)6]3+ but partially as [FeCl(H2O)5]3+ at FeCl3 concentration of 0.1–1 mol dm−3, and it exsits mainly as [FeCl2(H2O)4]+ at the concentration of 3–4 mol dm−3. In the diliquescent product of FeCl3, about a half of the solute is in the state of [FeCl4]− and the remaining half is likely to be in the state of [FeCl2(H2O)4]+. No indication was found for the dimer formation of FeCl3 even in the deliquescent product.
Elucidation of the Origin of Substituent Effects. Theoretical Investigation of Field Effect in Aliphatic Systems by ab initio Molecular Orbital Calculation Using Simple Models
Authors: Inamoto Naoki , Masuda Shozo , Niwa Jun
Published: July 2006

The electronic substituent effect in the aliphatic systems was investigated using ab initio calculation at STO-3G and 4-31G levels. The relative energy changes, δΔE, in isodesmic reaction of the 4-substituted bicyclo[2.2.2]octane-1-carboxylic acids were compared with those for 1-substituted bicyclo[2.2.2]octanes(XC8H13), CH3X, and H–X molecules perturbed with isolated pure point charges. The interaction energies between isolated dipole and point charge system, F–H···(±), were proportional to the reciprocal square of the distance between the center of dipole and the charge. Isodesmic reaction energies for the present systems at the distance longer than 5 Å can be practically explained by charge-dipole interaction. From the comparison of δΔE in XCH3···(±), XC8H13···(±), and XC6H5···(±) systems with those for X–H···(±), it was concluded that the pure field parameters for various substituents should be determined on the basis of the isodesmic reaction energy for X–H···(±) system. Correlations between δΔE in X–H···(±) system and the field parameters recently proposed, σF and σI(gas), were generally better in the cases calculated at 4-31G level than those at STO-3G level.
The Structure of Dichlorobis(l-proline)zinc(II)
Authors: Yukawa Yasuhiko , Yasukawa Noriko , Inomata Yoshie , Takeuchi Toshio
Published: July 2006

The title complex was prepared at pH 4.0. The crystal and molecular structures have been determined by X-ray diffraction. The crystals of ZnCl2(C5H9NO2)2, F.W.=366.55, were orthorhombic: space group P212121, a=13.527(3), b=16.263(3), c=6.598(1) Å, U=1451.4(5) Å3, Z=4, Dm=1.67 g cm−3, Dx=1.68 g cm−3, and μ(Mo Kα)=21.2 cm−1. The zinc atom is coordinated in a tetrahedral geometry to two chlorine atoms and the two carboxyl oxygen atoms of two l-proline ligands. Each l-proline is coordinated as a monodentate ligand.
The Synthesis and the Crystal and Molecular Structure of [Tris(dibutyl sulfoxide)bis(O,O′-diisopropyl dithiophosphato)neodymium(III)] [Tetrakis(O,O′-diisopropyl dithiophosphato)neodymium(III)] [Nd{(C3H7O)2PS2}2{(C4H9)2SO}3][Nd{(C3H7O)2PS2}4]
Authors: Ohki Yoshiyuki , Nakamura Masao , Suzuki Yasuo , Nagai Kiyofumi , Shimoi Mamoru , Ouchi Akira
Published: July 2006

The title complex has been synthesized, and its crystals and molecular structure has been determined by the use of the single-crystal X-ray-diffraction method. The crystal of Nd2C60H138O15P6S15, F. W.=2055.03, was monoclinic, with a space group of An; a=23.696(4), b=23.466(4), c=20.208(4) Å, β=111.22(2) °, Z=4, V=10475(4) Å3, Dm=1.30(3), Dx=1.30 Mg m−3, and μ(Mo Kα)=1.41 mm−1. The complex consists of cationic and anionic species, as is shown in the title. The metal atom of the cationic complex is hepta-coordinated and is in a pentagonal-bipyramidal geometry, while the anionic one is octa-coordinated and is in a dodecahedral geometry.
Cobalt(III) Complexes with Quadridentate Ligands. VI. The Preparation and Properties of “cis-β1” and β2-Isomers of the Salicylaldehydato(triethylenetetramine)cobalt(III) Complex
Authors: Yamamoto Yoshihisa , Toyota Eiko , Tsukuda Shoko
Published: July 2006

cis-β1 and β2-Salicylaldehydato(triethylenetetramine)cobalt(III) chloride dihydrate have been isolated from a reaction mixture of salicylaldehyde, cis-α or β-dichloro(triethylenetetramine)cobalt(III) chloride and Ag2O. The IR spectra of the complexes showed four strong absorption peaks in the 990–1100 cm−1 region. The complexes were assigned to the β-form. Their cis-β1 and cis-β2 configurations have been established by their 1H NMR spectra.
Utilization of “2-Pyrrolidone Hydrotribromide” in the Synthesis of Flavones
Authors: Takeno Noboru , Fukushima Tohoru , Takeda Shin-ichi , Kishimoto Kazuyasu
Published: July 2006

The reaction of flavanone with “2-pyrrolidone hydrotribromide” in tetrahydrofuran gave 3-bromoflavanone in a good yield. On the other hand, flavone was obtained in 97% yield when this reaction was carried out in dimethyl sulfoxide at 80 °C. Under the same conditions, most flavones were obtained from the corresponding flavanones in high purity and good yields.
The Reaction of Cyclopentanone with Carbon Disulfide and Glycine Esters
Authors: Fukada Naoaki , Yamamoto Kayoko
Published: July 2006

2-(Methoxy- and ethoxycarbonylmethylimino)cyclopentanecarbodithioic acids were synthesized from cyclopentanone, carbon disulfide, and glycine esters. In the presence of sulfur, glycine, alanine, and phenylalanine esters reacted to give the corresponding oxidatively coupled products of dithiocarboxylic acid.
Iodination of Benzene with Iodine and Metal Salts in Acidic Solvents
Authors: Shimizu Atsushi , Yamataka Kazunori , Isoya Toshiro
Published: July 2006

Iodobenzene was obtained by a reaction of benzene with molecular iodine in trifluoromethanesulfonic acid in oxygen atmosphere in the presence of vanadium salt as a catalyst. The method affords a new aromatic iodination process in which benzene is iodinated directly with molecular iodine.
Structural and Compositional Changes of Blue Orthorhombic Hydrogen Molybdenum Bronze, H0.30MoO3, by Vacuum Heating and Catalytic Activity for 1-Butene Isomerization
Authors: Sotani Noriyuki , Yoshida Noritetsu , Yoshioka Yukio , Kishimoto Shozo
Published: July 2006

Orthorhombic bronze, H0.30MoO3, was decomposed by vacuum heating to MoO2.86 With a rhombic MoO3 structure. The surface area increased slightly with the increase in the rhombic structure in which vacancies were produced. An approximate linear relationship was found between the catalytic activity of 1-butene isomerization and the hydrogen content(x) in the samples which were treated in air at 65 °C or in vacuo below 220 °C. On the other hand, the activity above 220 °C increased with the formation of vacancies.
The Reaction of [CoL2] or [CoL2(NO)] (L=4-Methyl-8-quinolinolate Ion) with Nitrogen Monoxide
Authors: Miki Eiichi , Tanaka Mikio , Saito Katsunori , Maejima Toshiaki , Mizumachi Kunihiko , Ishimori Tatsujiro
Published: July 2006

[Co(4mqn)2]·2H2O (4mqn=4-methyl-8-quinolinolate ion) reacted with nitrogen monoxide in CH2Cl2 or in DMF at room temperature to give [Co(4mqn)2(NO)] (1). [Co(4mqn)2]·2H2O and 1 reacted with nitrogen monoxide in 10 vol% pyridine–DMF and in pyridine at ca. 283–288 K to precipitate [Co(4mqn)2(NO)(py)] (2). When the reaction was carried out at ca. 293–303 K, [Co(4mqn)2(NO2)(py)] (3) instead of 2 was precipitated. From the filtrates, [Co(4mqn)2(NO3)(py)]·py·2H2O (4) was obtained. The gaseous product of the reactions giving 2 and 4, and 3 and 4, was dinitrogen oxide. The stoichiometries of the reactions in the pyridine–DMF and in pyridine were confirmed by mass analyses for the residual nitrogen monoxide and the produced dinitrogen oxide.
Cyclohepta[b][1,4]benzothiazines and Their Diazine Analogues. 1. Formation and Reactions of Cyclohepta[b][1,4]benzothiazines
Authors: Shindo Kimio , Ishikawa Sumio , Nozoe Tetsuo
Published: July 2006

2-Chlorotropone reacted with o-aminobenzenethiol to give 2-(o-aminophenylthio)tropone, which readily cyclized in dilute methanolic HCl to afford the title benzothiazine (9). Although 9 was stable under basic conditions, its N-methyl cation reversibly afforded the ring-opened 2-[o-(methylamino)phenylthio]tropone in alkali. Oxidation of 9 with hydrogen peroxide in methanol underwent a rearrangement reaction to afford (exclusively) phenothiazine and its 1-formyl derivative. A similar H2O2 oxidation of 10-methoxycyclohepta[b][1,4]benzothiazine gave mainly methyl phenothiazine-1-carboxylate and 3-formyl-1-methoxy phenothiazine. Further oxidation of these products with hydrogen peroxide yielded thier S-oxides and S,S-dioxides. The reactivities of these cycloheptabenzothiazines are discussed in connection with those of the O- and N-analogues.
Reactions of Tropone Tosylhydrazone Sodium Salt with Anthracene, 1,3-Diphenylisobenzofuran, and Phenylacetylene: [2+2] and [4+2] Type Cycloaddition Reactions of Cycloheptatrienylidene or 1,2,4,6-Cycloheptatetraene
Authors: Saito Katsuhiro , Omura Yoichi , Mukai Toshio
Published: July 2006

The reaction of tropone tosylhydrazone sodium salt (1) with anthracene gave a [4+2]-type adduct and the reaction of 1 with 1,3-diphenylisobenzofuran afforded endo- and exo-[4+2]-type adducts as well as a heptafulvene derivative. The reaction of 1 with phenylacetylene yielded a [2+2]-type adduct, which rearranged into 2-phenylindene upon heating. The addition reactions are thought to proceed via the allene intermediate, 1,2,4,6-cycloheptatetraene, which is a valence-bond isomer of the carbene intermediate, cycloheptatrienylidene, initially generated by the pyrolysis of 1. The photoreaction of adduct 3 with a high-pressure mercury lamp afforded a ring-closure product via the photobicyclization reaction of the cycloheptatriene moiety of the adduct. Thermal interconversions between the three products of the reaction of 1 with 1,3-diphenylisobenzofuran were investigated.
Chemoselective Reduction of Phenyl Ketones with Amino Alcohol–Borane Complexes
Authors: Itsuno Shinichi , Wakasugi Takashi , Ito Koichi , Hirao Akira , Nakahama Seiichi
Published: July 2006

A new reducing agent was prepared from borane and amino alcohols. The reagent is very effective for chemoselective reduction of ketones in the presence of esters, oxime ethers, tertiary amides, nitriles, halides, and acyl chlorides. The polymeric reagent prepared from borane and polymer-supported amino alcohol was also prepared easily. Aldehydes are highly selectively reduced to primary alcohols in the presence of ketone with the polymeric reagent. Simple filtration separated cleanly the unchanged ketone from the polymeric reagent which gave, after hydrolysis, only primary alcohol as the product. The polymeric reagent was regenerated by treatment with borane and could be reused.
Restricted Rotation Involving the Tetrahedral Carbon. LVI. NMR and Molecular Mechanics Studies on the Stereodynamics of 8,13-Dichloro-9-methoxy-1,4-dimethyltriptycene
Authors: Yamamoto Gaku , Oki Michinori
Published: July 2006

The 400 MHz 1H NMR spectrum of the title compound at −100 °C in dichloromethane revealed the presence of two isomers in a ratio of 88 : 12, which results from restricted rotation about the triptycyl–oxygen single bond. The major isomer was assigned to the ap rotamer on the basis of the low temperature 13C NMR spectrum. Dynamic NMR studies gave the activation parameters for the ap→±sc conversion: ΔH\eweq=11.9±0.5 kcal/mol (1 calth=4.184 J), ΔS\eweq=2.6±2.5 eu, ΔG\eweq200K=11.4 kcal/mol. Results of molecular mechanics calculations on the compound are discussed.
Substituent Effects on Azomethine Proton Chemical Shifts and 13C–H Coupling Constants in N-Benzylideneanilines. Generality of Inverse Substituent Effects on the Azomethine Proton Chemical Shifts
Authors: Akaba Ryoichi , Sakuragi Hirochika , Tokumaru Katsumi
Published: July 2006

Azomethine proton chemical shifts were measured for series of N-benzylideneanilines; C6H5CH=NC6H4X-4, 4-YC6H4CH=NC6H5, 4-NMe2C6H4CH=NC6H4X-4, 4-YC6H4CH=NC6H4NMe2-4, 4-NO2C6H4CH=NC6H4X-4, 4-YC6H4CH=NC6H4NO2-4, and 4-YC6H4CH=NC6H3(CH3)2-2,6. It was found that for N-benzylideneanilines carrying the variable substituents X on the anilino benzene ring the azomethine protons undergo upfield shifts with increasing electron-withdrawing property of X, whereas those for N-benzylideneanilines carrying the variable substituents Y on the benzylidene benzene ring exhibited expected lowfield shifts with increasing electron-withdrawing property of Y. 13C–H coupling constants for azomethine carbon–hydrogen bonds (J(13C–H)) were also measured for several derivatives of 4-NO2C6H4CH=NC6H4X-4, 4-YC6H4CH=NC6H4NO2-4, and 4-YC6H4CH=NC6H3(CH3)2-2,6. In contrast with the substituent effects on the azomethine proton chemical shifts, the coupling constant increases with increasing electron-withdrawing property of the substituent X or Y, regardless of the position of the substituents, indicating that a through-bond electronic effect of the substituent is a predominant factor to determine the magnitude of the coupling constant. These results show that the anomalous substituent effects on the azomethine proton chemical shifts are a general phenomenon in N-benzylideneanilines which carry variable substituents on the anilino benzene ring, and support our previous proposition that the anomaly is likely to originate primarily from the change of molecular conformation of these N-benzylideneanilines in solution.
Structural Study of Germanate Glasses Irradiated with γ-Rays and Thermal Neutrons
Authors: Nishida Tetsuaki , Katada Motomi , Takashima Yoshimasa
Published: July 2006

119Sn Mössbauer study of 60Co-γ ray and thermal neutron irradiated potassium germanate glasses containing a small amount of SnO2 has been performed to investigate the structural change of the glasses. The γ- and the thermal neutron-irradiation results in a disappearance of the distinct composition dependence of the Mössbauer parameters (quadrupole splitting and linewidth) observed before the irradiation. DTA measurement of the irradiated glasses also reveals drastic decreases in glass transition temperature (Tg) amounting to 20–120 °C and a simultaneous disappearance of the distinct composition dependence of Tg observed before the irradiation. This suggests a disruption of the chemical bond between germanium and oxygen atoms constituting GeO6 units. On the other hand, Mössbauer measurement at lower temperatures reveals that a parameter of intermolecular force constant (θ2M) obtained from the temperature dependence of the absorption area undergoes little change by the irradiations. This suggests that the irradiations bring about little changes in the ionic bond and the interatomic distance between tin and oxygen atoms, and that the irradiated germanate glasses can still be regarded as polymers from the lattice vibrational point of view.