bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the Aqueous Solutions of Guanidinium Salts. X. Activity Coefficients of Biguanide Salts in Aqueous Solutions at 25 °C
Authors: Miyajima Koichiro , Nakanishi Shigeo , Nakagaki Masayuki
Published: July 2006

Activity coefficients and molar conductivities of biguanide salts (Bg·HX) in aqueous solutions were determined at 25 °C. The values of mean activity coefficients of these salts were relatively low and lay in the order Bg·HOAc>Bg·HCl>Bg·HBr>ButylBg·HCl. These results were discussed in terms of the ion-ion interactions and the concomitant structural change of water.
The pKa Value and Volume Change for the Neutralization of [Co(edda)(H2NCH2CH2OH)]+
Authors: Kitamura Yoichi
Published: July 2006

The pKa value of [Co(edda) (H2NCH2CH2OH)]+ at 25 °C has been determined spectrophotometrically to be 5.01±0.05. The volume change for the equilibrium: [Co(edda)(H2NCH2CH2OH)]++OH−=[Co(edda)(H2NCH2CH2O)]0+H2O has been found to be 16.9±0.7 cm3/mol at 25 °C at an ionic strength of ca. 5 mM (1 mM=10−3mol dm−3).
Studies on the Configuration of N-Cyclohexylideneanilines with 13C-NMR Spectroscopy
Authors: Yoshida Masato , Kobayashi Michio
Published: July 2006

13C-NMR chemical shifts and the rates of thermal E-Z isomerizations of N-cyclohexylideneanilines have been determined and the substituent effects discussed.
On the Magnetic Susceptibility of Interacting Spin-pair Systems
Authors: Ohya-Nishiguchi Hiroaki
Published: July 2006

Modifying a general theory of antiferromagnetism proposed by Oguchi, the parallel and perpendicular magnetic susceptibilities (χ⁄⁄ and χ⊥ respectively) of antiferromagnetically interacting spin-pair systems have been formulated. As the parameter of the equations, κ=z|J′|⁄|J| , approaches zero, both of them coincide with a familiar equation of isolated spin-pairs. In the 0<κ≤1 range the maximum susceptibility and the Weiss constant are compared with those estimated exactly by the alternating antiferromagnetic linear-chain model. For 1<κ≤2, they can be characterized by a broad maximum and a transition to the antiferromagnetically ordered state. For κ>2, χ⁄⁄ in and χ⊥ show curves similar to those of a typical three-dimensional antiferromagnet. The χ⁄⁄a and χ⊥a 2,2-diphenyl-1-picrylhydrazyl–benzene (1:1) complex have been examined based on the theoretical results for κ=1.3. The magnetic susceptibilities of the other organic free radicals have been compared with the results calculated in the 0≤κ<1 range.
Simultaneous Measurement of Photoacoustic and Excitation Spectra for the Evaluation of Quantum Efficiencies of Uranium-mica Type Compounds
Authors: Sugitani Yoshinori , Kato Kenji
Published: July 2006

A new method of estimating the absolute quantum efficiency of a phosphor material based on the simultaneous measurement of photoacoustic and fluorescent excitation spectra is presented. The method is distinguishable from previous methods in that a reference material is not required. The method has been successfully applied to uranium-mica compounds. The transition rate constants for the radiative and non-radiative processes have been obtained on the basis of the quantum efficiency and fluorescence life time data.
Enhanced Reactivity of a Flavin Bound to Quaternized Poly(4-vinylpyridine) via 8-Position. A Model System of a Flavin Coenzyme Covalently-linked to Enzymest
Authors: Shinkai Seiji , Mori Kenji , Kusano Yumiko , Manabe Osamu
Published: July 2006

The rate constants for the reaction of the title flavin and the monomeric analogues with 1-benzyl-1,4-dihydronicotinamide (BzlNH), 1-nitroethanide ion, glutathione (GSH), and thiophenol (PhSH) were determined at 30 °C. Although the reactivity of 8α-AcHisFl is slightly improved as compared with that of unmodified flavin, the rate constants for 8α-PyFl which is expected to mimic the reactivity of protonated 8α-AcHisFl were significantly increased. The rate constants for the oxidation of anionic reductants(1-nitroethanide ion, GSH, and PhSH) were further increased by immobilization of the 8α-PyFl structure in quaternized 4VP polymers. The kinetic results implicate that (1) with regard to the action of a flavin covalently-linked to enzymes via histidine residue, the flavin must be more reactive in acidic pH region due to protonation of the histidine than in basic pH region, (2) the cationic polyelectrolyte environment accelerates selectively the oxidation of anionic reductants, and (3) the title flavin serves as a strong, selective oxidizing agent under ambient reaction conditions.
Ring-opening Reaction of Oxiranes, Oxetanes, and Tetrahydropyran by Mercury(II) Salts and Alkyl Halides
Authors: Watanabe Nanao , Uemura Sakae , Okano Masaya
Published: July 2006

The reaction of primary and secondary alkyl halides with mercury(II) acetate in oxiranes, oxetanes, and tetrahydropyran results in ring-opening to give the corresponding alkoxyalkyl acetates. Similar reactions with mercury(II) thiocyanate in oxetanes afford alkoxyalkyl isothiocyanate and thiocyanate, ROCH2C(R′)2CH2NCS and ROCH2C(R′)2CH2SCN, where the isomer ratios (N/S ratios) are 82–96/4–18. It is suggested that the reactions involve the initial formation of a three-, four-, or six-membered O-alkyloxonium ion intermediate and subsequent attack by XHgZ2−.
Effect of Alcohols on the Thermal Denaturation of Lysozyme as Measured by Differential Scanning Calorimetry
Authors: Fujita Yukihisa , Miyanaga Akihiko , Noda Yukinao
Published: July 2006

The thermal denaturation of lysozymc in aqueous alcohol solution has been investigated by differential scanning calorimetry. The alcohols employed were methanol, ethanol, isomeric propyl alcohols and butyl alcohols as monohydric alcohols, and ethylene glycol and glycerol as polyhydric alcohols. In monohydric alcohols, the temperature of denaturation, Td, of lysozyme decreased linearly with increasing alcohol concentration, which became pronounced with an increasing in the hydrophobic character. The enthalpy of denaturation, ΔHd, of lysozyme showed a complex dependence on the solvent composition; the ΔHd first increased with increasing alcohol concentration and then started decreasing at different concentrations for each alcohol. The branching of the alkyl chain decreased the destabilizing effect of the alcohol on the native conformation of the protein. In polyhydric alcohols, both Td and ΔHd increased with increasing alcohol concentration. The polyhydric alcohols stabilized the native conformation of the protein in contrast with the monohydric alcohols. The results are discussed in terms of the hydrophobic and hydrophilic characters of the alcohols.
Restricted Rotation Involving the Tetrahedral Carbon. XXVIII. Barriers to Rotation about a Csp3–C(=O) Bond in 9-(1-Methoxycarbonyl-1-methylethyl)triptycenes
Authors: Otsuka Soichi , Kihara Hiroshi , Mitsuhashi Tsutomu , \={O}ki Michinori
Published: July 2006

Restricted rotation about a Csp3–C(=O) bond in title compounds is found by 1H NMR spectra of the dl forms. The barriers to rotation are obtained by the DNMR method to be ca. 15 kcal/mol. Infrared spectra which exhibit two conformations in the dl and the meso forms are also reported.
The Synthesis of Mg3(PO4)2·8H2O and Its New Polymorphism
Authors: Kanazawa Takafumi , Umegaki Takao , Shimizu Masao
Published: July 2006

Bobierrite, Mg3(PO4)2·8H2O, could be synthesized from mixed solutions of Na2HPO4 and MgSO4 at an initial pH of 6.4–7.0 with the addition of Ca(NO3)2, CuSO4, NiSO4, gelatin, or agar, by heating at 80–90 °C for 2–48 h. X-Ray studies indicated the coexistence of two kinds of lattice in each synthetic Mg3(PO4)2·8H2O crystal. One phase (Phase 1) is monoclinic, space group P21/m or P21 with a=10.08(2), b=27.86(3), c=4.656(7) Å, and β=105.0(2)°. The other phase (Phase 2) is monoclinic, space group C2/m, C2, or Cm, with a=10.07(2), b=13.38(2), c=4.656(7) Å, and β=105.0(2)°. If a centrosymmetric space group C2/m is assumed for the latter, Phase 2 may be considered to be a new polymorph of Mg3(PO4)2·8H2O, one belonging to the vivianite series. Newberyite, MgHPO4·3H2O, was also formed in the above synthetic procedure. This phosphate was precipitated under slightly more acidic conditions than those where Mg3(PO4)2·8H2O was obtained.
Metal Halide Catalyst for Reduction of Nitric Oxide with Ammonia
Authors: Nishijima Akio , Kiyozumi Yoshimichi , Ueno Akifkimi , Kurita Minoru , Hagiwara Hiroyuki , Sato Toshio , Todo Naoyuki
Published: July 2006

Counter anions of active components on catalysts were found to affect catalytic activities for NO reduction with NH3. Halide ions promoted activity in copper and iron catalysts, but lowered it in chromium and manganese catalysts. The most favorable electronic state of a cation on catalysts was investigated by changing counter anions and/or carriers.
Isothiocyanates. I. Addition of Urea to Aroyl Isothiocyanates and Conversion of the Monoadducts into Monothiobiuret, 4-Thioxo-1,3,5-triazin-2-ones and 1,2,4-Thiadiazol-3-ones
Authors: Basyouni Mohamed Nabih , El-Khamry Abdel-Momen
Published: July 2006

The hitherto unknown 1-aroyl-2-thiobiurets were synthesized by addition of urea to aroyl isothiocyanates. Treatment of 1-benzoyl-2-thiobiuret with concentrated hydrochloric acid effected hydrolysis to monothiobiuret. On the other hand, treatment of 1-aroyl-2-thiobiurets with alkali gave 6-aryl-4-thioxo-1,2,3,4(or 2,3,4,5)-tetrahydro-1,3,5-triazin-2-ones. Oxidation of the 1-aroyl-2-thiobiurets with hydrogen peroxide in the presence of hydrochloric acid gave 5-aroylamino-2.3-dihydro-1,2,4-thiadiazol-3-ones.
The Effect of Configuration Interaction on the π-Bond Orders, and the Molecular Geometry of Coronene in Its Ground State
Authors: Nakayama Mitsunobu , Morihashi Kenji , Igarashi Masato , Suzuki Keizo
Published: July 2006

Semiempirical MC-LCAO-MO calculations have been made on the ground-state coronene. The inclusion of the off-diagonal terms in the MC bond-order formula is, in this case, essential to improve the bond orders and the bond lengths over the usual single configuration calculation.
ESR and ENDOR Studies of the Hindered Internal Rotation of Higher Alkyl Groups. 2,6-Di-t-butyl-4-alkylphenoxyl Radicals
Authors: Shimoda Fumio , Hanafusa Terukiyo , Nemoto Fujito , Mukai Kazuo , Ishizu Kazuhiko
Published: July 2006

ESR or ENDOR spectra were observed for the 2,6-di-t-butyl-4-methyl-, 4-ethyl-, 4-isopropyl-, and 4-cyclohexylphenoxyl radicals. From the analyses of the temperature dependence in β-proton splittings, the energy barriers to internal rotation of the alkyl group were estimated.
Complexes of Zinc-group Metals with 8-Amino-2-methylquinoline
Authors: Furuhashi Akiko , Yokota Hiroshi
Published: July 2006

Some complexes of zinc-group metals with 8-amino-2-methylquinoline have been synthesized. They are seemed to have a monomeric tetrahedral form except for the mercury(I) complex containing a perchlorate ion as a counter anion.
The Preparation of N-Benzyl-α-ethoxycarbonylnitrone and Its Reactions with Some Olefins
Authors: Inouye Yoshinobu , Watanabe Yuko , Takahashi Satoru , Kakisawa Hiroshi
Published: July 2006

N-Benzyl-α-ethoxycarbonylnitrone (1) was prepared from ethyl glyoxylate and N-benzylhydroxylamine. The reactions of 1 with isobutylene, methyl acrylate, and methyl crotonate are described.
Spectrophotometric Study on the Complex Formation of Hydroperoxide with Tetraphenylporphyrin Cobalt(II)
Authors: Yamada Teruaki , Kamiya Yoshio
Published: July 2006

The rate constants, activation energies, activation entropies and equilibrium constants for the coordination of 1,2,3,4-tetrahydro-1-naphthyl hydroperoxide (THP), 1-methyl-1-phenylethyl hydroperoxide (CHP) and t-butyl hydroperoxide (BHP) to para-substituted tetraphenylporphyrin Co(II), Co(p-X)TPP (X=OCH3, H, Cl) were obtained by the visible spectral method at 235–245 K. The rate constants of coordination were k=0.097–2.03×102 M−1 s−1, the equilibrium constants being K=0.692–2.5×10−6 M−1. As a para-substituent effect on k and K, the constants were found to increase with increase in the electron donating property of the substituent group. They also depend on the kind of hydroperoxide, the rate constants decreasing in the order kTHP>kCHP>kBKP, and the equilibrium constants in the order KCHP>KBHP>KTHP. Activation energies were 7.0—7.8 kcal mol−1 and activation entropies −21–−25 cal K−1. No spectral change by the addition of hydroperoxide to CuTPP and NiTPP was observed.
Vinyl Polymerization. 394. Radical Polymerization of Methyl Methacrylate Initiated with Saccharomyces Cerevisiae
Authors: Imoto Minoru , Ouchi Tatsuro , Morita Eijiro , Yamada Minoru , Tokuyama Tai , Obata Hitoshi
Published: July 2006

The polymerization of methyl methacrylate with Saccharomyces cerevisiae was carried out in water, the reaction being found to proceed through a radical mechanism. The effect of the mass of reagent on the rate of polymerization and selectivity of vinyl monomer were studied. The isolated cell wall showed remarkable activity for polymerization. The change of surface of the polymerization system was observed with a scanning electron microscope.
Polarographic Catalytic Currents Produced by Cytochromes c in Ammoniacal Buffers Containing Cobalt Ions. I. Significance of Heme Group
Authors: Ikeda Tokuji , Kinoshita Hideaki , Yamane Yoshiyuki , Senda Mitsugi
Published: July 2006

Polarographic behavior of the Brdicka current (catalytic current produced by proteins in ammoniacal buffers containing cobalt ions) of cytochromes c from five sources (horse, chicken, and tuna hearts, C. krusei and S. cerevisiae) and of modified horse cytochromes (metal-substituted, metal-free, and heme-free cytochrome, and carboxymethylated cytochrome at methionyl residues) was investigated at dme and hmde. The results indicate that the heme group and its sixth ligand are important in determining the Brdicka current-activity of cytochromes c. Replacement of the sixth heme ligand from Met to Lys reduced the Brdicka current-activity by about onehalf. Brdicka current of D. vulgaris cytochrome c3 was interpreted as due to four Lys-liganded heme groups.
Studies on Bromites. III. Isolation and Characterization of Quaternary Ammonium Bromites
Authors: Kageyama Toshifumi , Yamamoto Tamotsu
Published: July 2006

Bromite, BrO2−, could be easily stabilized and isolated as quaternary ammonium salts by the reaction of sodium bromite with the corresponding ammonium halides. The bromites are more stable and non-hygroscopic in comparison to sodium bromite. The stability of the ammonium bromites depends a great deal on the structure of the ammonium groups.
A New Reaction of a 7,7-Diethoxybicyclo[4.2.0]octan-2-one Derivative. The Formation of the Bicyclo[3.2.1]octane Skeleton
Authors: Yanagiya Mitsutoshi , Tomita Takamasa , Matsumoto Takeshi
Published: July 2006

2,2-Diethoxytricyclo[6.4.0.01,4]dodecan-5-one was rearranged to 11-ethoxytricyclo[7.2.1.01,6]dodec-10-en-12-one under GLC conditions (Thermol-3 on Shimalite, 200 °C) in an 87% yield.
Some Reactions on 4H-Cyclopenta[def]phenanthrene-8,9-dione
Authors: Yoshida Masaaki , Kadokura Atsushi , Minabe Masahiro , Suzuki Kazuo
Published: July 2006

The oxidation of 8,9-dihydro-4H-cyclopenta[def]phenanthrene gave the 4-ketone by treatment with Triton B-oxygen, and afforded 8,9-diketone by the action of chromium (III) salt. The reduction of the quinone yielded the corresponding meso- and dl-diols.
Reactions of Enamino Ketones. VII. The Photochemical Reaction of 4-Methylamino-3-penten-2-one and 2,4-Pentanedione with Benzophenone
Authors: Tokumitsu Takao , Hayashi Takayuki
Published: July 2006

The photochemical reaction of 4-methylamino-3-penten-2-one with benzophenone gave N-(2,2-dipenyl-2-hydroxyethyl)-4-amino-3-penten-2-one. The reaction of 2,4-pentanedione gave oxetane, resulting from the cycloaddition of benzophenone to the double bond of the enol form.
Reaction of Ethyl Azidoformate with Morpholines
Authors: Tsuchida Teruko , Koyama Kikuhiko , Mitani Michiharu , Takeuchi Hiroshi
Published: July 2006

Ethyl azidoformate (1) reacts rapidly with morpholine to give morpholinium azide and 4-(ethoxycarbonyl)morpholine in good yields. With 4-methylmorpholine (3), however, the azide 1 reacts at 115 °C with evolution of nitrogen to give formal nitrene-insertion products, 4-methyl-3-(ethoxycarbonylamino)morpholine and 4-(ethoxycarbonylaminomethyl)morpholine. There has not been found any product which might arise from the nitrene–insertion into C–H bond adjacent of oxygen of 3. These results can be accounted for on the basis of the n-donor abilities of heteroatoms, O and N.
Reaction of Dibenzyl Disulfide and Analogues with Na2Sx–NaOH Supplementary Data for Mechanism for Reaction of p-Nitrotoluene with Na2Sx
Authors: Ogata Yoshiro , Nakagawa Yoshiaki
Published: July 2006

Reaction of dibenzyl disulfide with aquoethanolic NaOH gave benzaldehyde and α-toluenethiol. On the other hand, the reaction of dibenzyl disulfide with Na2Sx in the presence of NaOH gave preferentially benzaldehyde alone. These facts are explained by the further reaction of α-toluenethiol with Na2Sx giving benzaldehyde and support our mechanism proposed previously for the reaction of p-nitrotoluene with Na2Sx.
Structural Study of Optical Resolution. VII. The Crystal Structure of (−)589-Oxalatobis(ethylenediamine)cobalt(III) Hydrogen-d-tartrate Dihydrate and Comparison between the Crystal Structures of the More- and Less-soluble Diastereoisomers
Authors: Kuramoto Masahiro , Kushi Yoshihiko , Yoneda Hayami
Published: July 2006

The single crystals of the more-soluble diastereoisomeric salt including the hydrogen-d-tartrate anion as a resolving agent, (−)589-[Co(ox)en2]H-d-tart·2H2O, have been newly obtained, and the crystal structure has been determined by three-dimensional X-ray analysis. The crystals are orthorhombic, space group P21212, Z=4, a=16.583(5), b=14.186(5), and c=7.403(2) Å. The structure was solved by the heavy-atom method and refined by the block-diagonal least-squares method to a conventional R-value of 0.044 for the 1907 independent reflections. One of the two ethylenediamine rings is of the ob form. The other ring has a conformational disorder, the proportion of the ob to the lel form being 50:50. The absolute configuration of the complex cation is denoted as Δ[(50%-δ, 50%-λ)δ]. The framework of the crystal structure is built up of a stack of complex cations and H-d-tart anions along the c-axis in a “head-to-tail” arrangement. The shortest interatomic distance between the H-d-tart anions is 2.473 Å(O–H···O), while that between the complex cations is 2.995 Å (N–H···O). A comparison of the crystal structure of the more-soluble diastereoisomer with that of the lesssoluble one revealed that the {H-d-tart}∞ chain is structurally different from that in the latter; the chain is spiral in the latter, but not in the former. The structural feature in the {H-d-tart}∞ chain is considered to play an important role in the discrimination of the chirality of the [Co(ox)en2]+ cation. The conformational disorder is discussed in connection with the dehydration of crystals.
Partition of Tris(acetylacetonato)chromium(III) and Its Temperature Dependence in the Systems of Dodecane/(Water–Organic Solvent Mixture)
Authors: Awano Hiroshi , Watarai Hitoshi , Suzuki Nobuo
Published: July 2006

The partition constants Kt\ominus of tris(acetylacetonato)chromium(III) between dodecane and water–organic solvent mixtures have been measured. The organic solvents used as co-solvents were acetonitrile, N,N-dimethylformamide, methanol, ethylene glycol, and dimethyl sulfoxide which are all miscible with water but not with dodecane. From the temperature dependence of Kt\ominus the thermodynamic parameters for the transfer of the complex from dodecane to the mixed solvents have been determined. The dependences of the partition constants on solvent composition of the aqueous phase have been interpreted in terms of changes in the internal pressure and the volume upon mixing of water with the organic co-solvents. The standard transfer enthalpies have been correlated with the excess enthalpies of the mixed solvents.
A Development in Polarization Experiments; Emission Spectra of Anthracene, Dibenzothiophene, and Xanthone in Stretched Polyethylene Films
Authors: Terada Tomoyuki , Koyanagi Motohiko , Kanda Yoshiya
Published: July 2006

The polarized emission spectra of anthracene, dibenzothiophene, and xanthone have been studied in stretched polyethylene films at 77 and 4.2 K. Applicability and advantage of this method are examined by virtue of conventional polarization technique and modulation technique. The latter leads us to finding of an important role of a nontotally symmetric vibration, the b3g ring vibration at 1655 cm−1, in the fluorescence spectrum of anthracene. An assignment for several prominent vibrational bands in the phosphorescence spectrum of dibenzothiophene is proposed from detailed analysis of the modulation polarization spectrum at 77 K. The phosphorescence properties of xanthone are also investigated.
Effect of Ultraviolet Ray on Graphite Fluoride in Organic Solvents
Authors: Watanabe Nobuatsu , Ueno Kazuo
Published: July 2006

Graphite fluoride, (CF)n, was photolyzed in alcohols and hydrocarbons. Hydrogen fluoride was formed in each case. Alcohols were partially converted into the corresponding carbonyl compounds by the reaction 2(C–F)+RR′CHOH\oversethν→2(C)+2HF+RR′C=O. ESCA measurement revealed that the fluorine at the surface decreases more rapidly than that of the inner region of (CF)n particle, the inner region being also photolyzed. Results of DTA measurement indicate that the irradiation reduces the thermostability of (CF)n.
Friedel-Crafts Reaction of Aromatics with Epoxides. Stereochemistry and Selectivities
Authors: Inoue Masashi , Chano Keizo , Itoh Osamu , Sugita Toshio , Ichikawa Katsuhiko
Published: July 2006

The Friedel-Crafts reaction of toluene and anisole with 2-methyloxirane and 2,3-dimethyloxiranes was examined. The inter- and intramolecular selectivities of 2-methyloxirane were between those of conventional methylation and isopropylation. It was also found that all the positional isomers formed by the aluminum chloridecatalyzed reaction of toluene and anisole had almost completely inverted configurations of the epoxide carbons. These results are explained by a mechanism of the SN2 type. Diminished stereospecificities were observed in aluminum bromide-catalyzed reactions.
Synthesis of l-Epicapreomycidine
Authors: Teshima Tadashi , Konishi Kunikazu , Shiba Tetsuo
Published: July 2006

A cyclic guanidino amino acid, l-epicapreomycidine, isolated from hydrolyzates of protease inhibitors such as chymostatin and elastatinal was synthesized. This amino acid is a diastereomer of l-capreomycidine which is a component amino acid of tuberactinomycin N,O and capreomycin. A new synthetic route from β-hydroxy-Dl-orni thine via an aziridine compound to Dl-capreomycidine was applied to the synthesis of l-epicapreomycidine starting from erythro-β-hydroxy-l-ornithine. A convenient and one-step technique to obtain l-erythro form from a mixture of four diastereomers of β-hydroxyornithine by means of enzymatic reaction was newly exploited. The synthetic l-epicapreomycidine obtained was identical with natural one in all respects, thus confirming the proposed structure.
Aromatization of Ring-A in α-Bromocholestan-6-ones
Authors: Shafiullah  , Islamuddin
Published: July 2006

Pyridine promoted dehydrohalogenation of β-chloro-5-bromo-5α-cholestan-6-one resulting in ring-A aromatization with expulsion of C-10 angular methyl group to give 19-norcholesta-1,3,5(10)-trien-6-one along with 3a,5-cyclo-5α-cholest-7-en-6-one, cholesta-2,4-dien-6-one, and 5α-cholestane-3,6-dione. Similar treatment of 3β-chloro-5,7β-dibromo-5α-cholestan-6-one ends up with the aromatization of ring-A with migration of C-10 angular methyl group to give 1-methyl-19-norcholesta-1,3,5(10)-trien-6-one.
INDO Molecular Orbital Interpretation of Thermal Singlet Oxygen-complex Generation by Strained Acetylenes
Authors: Ohkubo Katsutoshi , Sato Hiroyuki
Published: July 2006

A three-center interaction between the (πu)y of strained XC≡CX (X=H,F, or OCH3) and the (πg)y of 3O2 separated the two half-occupied πg MOs of 3O2 on an energy scale of 428–494 kJ/mol causing spin inversion in 3O2. A perepoxide-type 1O2–XC≡CX intermediate once formed is transformed into a stable dioxetene-type 1O2 complex from which the free generation of 2O2 was found to be difficult.
The Mössbauer Effect of 119Sn in the Dimethylbis(8-quinolinolato)tin(IV) Single Crystal
Authors: Negita Hisao , Boku Ryukei , Ichiba Sumio
Published: July 2006

The Mössbauer absorption spectrum of 119Sn in the single crystal of dimethylbis(8-quinolinolato)tin(IV) was studied by an intensity-tensor method. The orientation of the principal axes of the electric-field gradient (EFG) was discussed from the point of view of point-charge formalism.
Kinetics of Dissociation of the Hydrogen Bond in the (n,π*) Singlet State of 9,10-Diazaphenanthrene
Authors: Yamazaki Iwao , Takeda Hiroyuki , Baba Hiroaki
Published: July 2006

Changes of fluorescence properties with temperature have been examined for 9,10-diazaphenanthrene (DAP) in proton-donating solvents. From a kinetic analysis, the rate constant for dissociation of the hydrogen bond in the (n,π*) singlet state of DAP is evaluated to be 4.3×108 s−1 at 113 K, and the activation energy of the dissociation is 10.0 kJ/mol.
Formation of Five-coordinate Ni(II) Complexes with 2,12-Dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),2,11,13,15-pentaene Analogs and Halide Ions in Nitromethane
Authors: Mochizuki Katsura , Ito Tasuku , Fujimoto Masatoshi
Published: July 2006

Formation of 5-coordinate Ni(II) complexes of the title quadridentate ligands and halide ions (Cl−, Br−, and I−) in nitromethane was investigated. Some of the formation constants were estimated by means of curve-fitting method.
Effect of Plasticizer on the Selectivity of Potassium-selective PVC Membrane Electrodes Based on Bis(crown ether)s
Authors: Tamura Hiroshi , Kimura Keiichi , Shono Toshiyuki
Published: July 2006

Potassium-selective PVC membrane electrodes based on bis(crown ether)s containing benzo-15-crown-5 moiety were prepared, o-nitrophenyl octyl ether (NPOE) or dipentyl phthalate (DPP) being used as a plasticizer. Selectivity coefficients for various monovalent ions were measured. The preference of potassium over sodium in the bis(crown ether) (I; n=5)–NPOE electrode system is close to that in the valinomycin system.
Synthesis and Magnetism of MIICuII3-type Tetranuclear Complexes, the Nickel(II) and the Cobalt(II) Complexes with N,N′-Bis(aminoalkyl)oxamidatocopper(II)
Authors: Okawa Hisashi , Kawahara Yukitaka , Mikuriya Masahiro , Kida Sigeo
Published: July 2006

Hetero-metal tetranuclear complexes, [N,N′-bis(aminoalkyl)oxamidatocopper(II)]cobalt(II) and tris[N, N′-bis(aminoalkyl)oxamidatocopper(II)]nickel(II) perchlorate (or nitrate), were synthesized and characterized. Gryomagnetic investigation demonstrated that a considerably strong antiferromagnetic spin-exchange interaction is operating between copper(II) and cobalt(II) or nickel(II) ions.
Infrared Spectra and Intramolecular Hydrogen Bonding of p-(Substituted phenoxy)-α-(dialkylamino)acetanilides
Authors: Abe Kazuhisa , Hirota Minoru , Sugiura Michiharu , Hamada Yoshiki
Published: July 2006

The title compounds were synthesized with pharmaceutical interests, and their infrared spectra in the NH and carbonyl stretching regions were measured. By comparing the spectra with those of p-phenoxyacetanilide, intramolecular hydrogen bonds are shown to exist between the amide NH and the α-dialkylamino groups.
Gas Chromatography under the Column Outlet Pressure Higher than Atmospheric
Authors: Takeuchi Koji , Ohzeki Kunio , Kambara Tomihito
Published: July 2006

The effects of column outlet pressures on the HETP vs. carrier gas velocity curves are discussed on the basis of KOS theory. It is shown that when a column is operated at a constant outlet pressure higher than atmospheric the minimum of H-\baru curve shifts towards lower HETP and \baru values, and on the contrary the operation at reduced outlet pressure results in the shift of the minimum towards higher HETP and \baru values. The separation factor and number of theoretical plates obtained by a column operated at the outlet pressure of 4.0 atm are superior by ca. 10% to those obtained by normal gas chromatography.
Base-catalyzed Autoxidation of Fluorene in the Presence of Phase Transfer Catalysts
Authors: Yamashita Junzo , Ishikawa Shinji , Hashimoto Harukichi
Published: July 2006

Base-catalyzed autoxidation of fluorene to fluorenone has been carried out in an aqueous potassium hydroxide–benzene two-phase system in the presence of 18-crown-6 as a phase transfer catalyst. The initial rate of oxidation is proportional to the amount of fluorene. The addition of 18-crown-6 leads to the increased concentration of potassium hydroxide and water in the benzene phase, which is responsible for the increased rate of oxidation. Increasing the concentration of potassium hydroxide in the aqueous phase increases the concentration of 18-crown-6 and potassium hydroxide in benzene, resulting in a large increase in the rate of oxidation. The ease of oxidation with respect to the base is KOH>NaOH>LiOH>Ba(OH)2. Less polar solvents such as cyclohexane used as an organic phase decrease the oxidation rate.
Structural Aspects of Catalytic Activities of Thiazolium Salts in Benzoin Condensation Reaction in Methanol
Authors: Yano Yumihiko , Tamura Yoshiharu , Tagaki Waichiro
Published: July 2006

The rates of benzoin condensation catalyzed by thiazolium salts of varying structures have been determined in methanol containing triethylamine as the base by the method of gas chromatography. The condensation activity was observed not to be linearly correlated with the acidities of 2-position of catalyst thiazolium ring. The dimethylamino substituent was found not to act as an internal base for benzoin condensation, but rather exerted an inhibitory effect. In general, the effects of N-substituent on the rate of benzoin condensation were small. However, a large steric hindrance was observed for 3-methyl-4-menthylthiazolium perchlorate.
Photocycloaddition Reaction of Alkyl-substituted 1,4-Naphthoquinones with Olefins. Substituent Effects on Controlling the Orientation of Cycloaddition Reaction
Authors: Maruyama Kazuhiro , Narita Noritsugu
Published: July 2006

Photolysis of a benzene solution of 2-alkyl- or 2,3-dialkyl-substituted 1,4-naphthoquinone mixed with an arylsubstituted ethylene afforded 3,4-benzobicyclo[4.2.0]octene-2,5-dione derivatives (cyclobutane type adducts) in a good yield without any other types of products. The orientation of the cycloaddition was likely to control by the adverse van der Waals repulsion of the substituents of the quinone and olefin in addition to the electronic effects of the substituents. The predominant factor orientating the cycloaddition seems to play the van der Waals repulsion due to the substituents both of quinone and olefin.
Carbon–Carbon Bond Formation by the Use of Chloroiodomethane as a C1 Unit. II. The Preparation and Synthetic Application of 1-Chloro-3-iodoheptane
Authors: Miyano Sotaro , Hokari Hiroshi , Umeda Yoshiharu , Hashimoto Harukichi
Published: July 2006

Terminal alkenes, R–CH=CH2 (R=Et, n-Pr, n-Bu, n-Hex), were readily transformed into 1-chloro-3-iodoalkanes by the AIBN-induced free radical addition of chloroiodomethane. Thus, 1-chloro-3-iodoheptane was obtained from 1-hexene in an 88% yield; this in turn was allowed to react with dialkyl malonates in the presence of alkoxides in alcohols to give dialkyl 2-butylcyclobutane-1,1-dicarboxylates and dialkyl (E)-3-octene-1,1-dicarboxylates (7), either of which could be obtained preferentially by the choice of the experimental parameters. The olefinic product, 7, was further utilized for the synthesis of (E)-5-decenyl acetate and/or 1,4-nonanolide.
Kinetics of the Gas-phase Photochlorination of Dichloromethane in a Tubular Photoreactort
Authors: Sugawara Takuo , Suzuki Makoto , Ohashi Hiroyasu
Published: July 2006

The gas-phase photochlorination of dichloromethane was conducted at a low extent of conversion from 9 °C to 100 °C in a tubular flow reactor irradiated by means of a circular array of low-pressure mercury lamps. The kinetics were studied with due consideration taken of the radial variation in light intensity across the reactor and with the proper selection of kinetic equations, including the recombination of dichloromethyl radicals as the dominant termination step. The dependence of the absorbed radiant energy on the chlorine concentration was well simulated by the use of the radial-light and line-source model. The predominance of the observed production rate of hydrogen chloride over that of chloroform was also reproduced well by the appropriately selected kinetic expressions, without any use of the long-chain approximation. The recombination rate constant of dichloromethyl radicals was determined to be 1013.5 cm3 mol−1 s−1; this is larger than the previously reported value by the factor of 12.6, and is in fair agreement with the theoretical value, 1013.3−13.4, calculated from the statistical factor, and with the collision rate constant based on the hard-sphere model.
Thermal Diffusion Measurements of Symmetric Tetraalkylammonium Bromides in Water
Authors: Yogi Zen’ei , Kitano Hiroshi , Toma Izumi , Kijima Kazuhiro , Ikeda Toshio
Published: July 2006

The Soret coefficients for 0.01 M aqueous solutions of R4NBr (R=H, Me, Et, n-Pr, n-Bu, n-Pen, n-Hex, and n-Hep) were measured by the Snowdon-Turner conductimetric method with accuracy within ±0.1%, and were found to be −0.13, −4.18, −7.16, −9.05, −9.61, −9.47, −8.65, and −7.34, respectively in 10−3 K−1, at the mean temperature 25 °C. They show a maximum at the carbon number 4 or 5 in R, whereas the diffusion coefficients show a minimum at the same carbon number in an exactly inverse manner. The apparatus and procedure are described.
13C Spin-lattice Relaxation and Molecular Motion in Liquid and Plastic 2,2-Dimethylpropanoic Acid
Authors: Hasebe Tooru , Nakamura Nobuo , Chihara Hideaki
Published: July 2006

Individual 13C spin-lattice relaxation times (T1) of 2,2-dimethylpropanoic acid (DMPA) in plastic and liquid phases have been measured by a pulse Fourier transform NMR technique at 15.036 MHz. In the plastic phase (278.9 K to 308.5 K), the minimum in the T1 was observed; 0.35 s at 289.0 K for methyl carbon and 2.67 s at 289.0 K for quaternary carbon. The temperature dependence of the T1 was analyzed by extending Woessner’s treatment to the case of three independent degrees of reorientational freedom; internal methyl reorientation, t-butyl reorientation about C–COOH bonding axis, and isotropic molecular reorientation. In the plastic phase the isotropic reorientation of molecular dimeric units formed through hydrogen bonds is responsible for the 13C-relaxation. The activation parameters for this motion were obtained; Ea=56.4±6.3 kJ mol−1 and τ0=(4.6±4.0)×10−19 s. In the liquid phase from the melting point to 351 K, the T1 showed a monotonous increase with increasing temperature. In this liquid phase the isotropic molecular reorientation of the dimer units of DMPA is also responsible for the 13C-relaxation. The Ea of 23.4±2.4 kJ mol−1 and the τ0 of (9.6±5.8)×10−14 s for this motion were obtained.
VAPOUR PRESSURE, SURFACE TENSION AND DENSITY OF OSMIUM TETROXIDE
Authors: Ogawa Eijiro
Published: July 2006

(I) The structure of osmium tetroxide was discussed.

(II) It was made clear that the phenomenon of an enantiotropy of osmium tetroxide set forth by Krauss did not exist.

(III) The vapour pressure of osmium tetroxide was measured between 15° and 130°C. Melting point, boiling point, heat of sublimation, heat of vaporization, heat of fusion, and free energy change among solid, liquid and vapour were determined.

(IV) Surface tensions and densities from melting point up to 150°C. were determined.

(V) Osmium tetroxide in liquid state somewhat associates below 70°C., though it is a normal liquid above 75°C.

(VI) The critical temperature was determined as 405°C.
Fuel Mixing Effects on Propagation of Premixed Flames. II. Hydrogen+Methane Flames
Authors: Kunioshi Nilson , Fukutani Seishiro
Published: July 2006

Fuel mixing effects on flame propagation were investigated with hydrogen and methane, whose flames, respectively, propagate through two different kinds of mechanisms. The calculated burning velocities did not show linearity with the hydrogen content in the fuel. The addition of only 5% of methane to hydrogen reduces the burning velocity by 20%, notoriously inhibiting the combustion of the mixture. This is caused by obstruction of the harmonious progression of two key chain-branching reactions, resulting in a decrease in hydrogen atom production at the flame front. However, the upstream flux, at the ignition point, of chemical energy due to diffusion of hydrogen atoms from the flame front and the integrated amount of heat released in the low-temperature region did show linearity with the burning velocity. Therefore, it was found that even for flames of mixed fuels whose components burn individually through different propagation mechanisms, the burning velocity can be expressed as a simple linear function of the upstream chemical energy flux or of the amount of heat released in the low-temperature region.
Theoretical Study of Aluminum-Sodium Bimetallic Clusters. I. Geometrical and Electronic Structures of AlnNa (n = 1–4)
Authors: Matsuzawa Hidenori , Hanawa Toshiyuki , Suzuki Kazunori , Iwata Suehiro
Published: July 2006

The geometrical and electronic structures of several small aluminum-sodium mixed clusters AlnNa and pure aluminum clusters Aln (n = 1–4) were examined with ab initio MO calculations. All the calculations were carried out at the restricted Hartree–Fock level of approximation for both closed and open shell systems. The structures of the most stable Aln cluster and neutral and cationic AlnNa clusters were fully optimized. The low and high spin multiplicities of each cluster were examined. The structure of the most stable state of the AlnNa clusters keeps the frame of the Al cluster unchanged, and the Al–Al distances become shorter than in the corresponding Al clusters. The calculated ionization energies by the ΔSCF method are qualitatively in agreement with the corresponding experimental values. The highest occupied molecular orbital of the neutral clusters suggests that an ionized electron is localized on the Al atoms, but the large orbital reorganization by ionization results in a substantial net positive charge on a sodium atom. The nature of chemical bond for the clusters is also examined.
Transformatiom of Propargylic Alcohols into Enones
Authors: Shigemasa Yoshihiro , Oikawa Hiroshige , Ohrai Shin-ichiro , Sashiwa Hitoshi , Saimoto Hiroyuki
Published: July 2006

α,α-Disubstituted propargylic alcohols were transformed into enones by the catalysis with Ag(I) or Ag(I)–Me3SiCl under the mild conditions. This procedure provides a new synthetic method of α,β-unsaturated ketones having an oxygen function at α′ position from 2-butyne-1,4-diol derivatives. 3-Acetoxy-1,4,4-triphenyl-3-buten-2-one was obtained from 4-acetoxy-1,1,4-triphenyl-2-butyn-1-ol by the catalysis with tin(IV) chloride or aluminium chloride.
Synthesis, Properties, and Crystal Structures of a Series of Dinuclear Manganese(III) Complexes with 1,5-Bis(salicylideneamino)-3-pentanol and Various Anions: Formation of a Tetranuclear Manganese(III) Complex
Authors: Mikuriya Masahiro , Yamato Yo , Tokii Tadashi
Published: July 2006

μ-Alkoxo-bridged dinuclear and tetranuclear manganese(III) complexes with 1,5-bis(salicylideneamino)-3-pentanol (H3L), [Mn2(L)(CH3O)Cl2(CH3OH)2] (1), [Mn2(L)(CH3O)(CH3COO)(CH3OH)2]X (X = Br (2), I (3)), [Mn2(L)(CH3O)(CH3COO)(CH3OH)Y] (Y = NCS (4), N3 (5), ClO4 (6)), [Mn2(L)(CH3O)(NCO)2(H2O)2] (7), and [Mn4(L)2(O)2(CH3COO)2]·4H2O·2CH3OH (8) have been prepared and characterized by infrared and electronic spectra, magnetic susceptibilities, and cyclic voltammetry. The molecular structures of 1–5, 7, and 8 were determined by the single-crystal X-ray structure analyses. All the complexes except for 8 have a similar structure, where Cl−, CH3COO−, N3−, NCS−, CH3OH, or H2O is incorporated into the fifth or sixth coordination site on the Mn2(L)(CH3O) plane. The structure of 8, is a tetramer consisting of two Mn2(L)(O)(CH3COO) dimeric units held together through the oxo ions and the phenoxo-oxygen atoms of L. The spectral and magnetic properties were discussed in relation to the crystal structures.
Dual Reactivity of Methoxymethyl Benzenesulfenate in Nucleophilic Substitution
Authors: Okuyama Tadashi , Fueno Takayuki
Published: July 2006

Hydrolysis of methoxymethyl benzenesulfenate is catalyzed by both acid and base. Acid-catalyzed hydrolysis is further accelerated by various nucleophiles like halide ions, thiocyanate, dialkyl sulfide, and the substrate itself. The catalytic constants coincide with those for ethyl benzenesulfenate within 2-fold in magnitude. The nucleophilic reactivity strongly suggests the reaction at the sulfenyl sulfur, but examination of the products from the 18O-labeled substrate showed that the bond cleavage occurs mostly between the oxygen and the proformyl carbon except for the acid-catalyzed water reaction which undergoes the S–O cleavage. A mechanism for a nucleophilic reaction at the sulfur to form a sulfurane intermediate which breaks down with the C–O cleavage is presented. The hydrolysis rate is also strongly dependent on the second order of buffer concentrations in carboxylate and tertiary amine buffer solutions. The third-order term involves both the general acid and the conjugate base of the buffer, and the latter reacts at the sulfur as a nucleophile in the rate-determining step but leads to the C–O cleavage in the same way as the other catalytic nucleophiles.
Catalytic Hydrogenation of Dehydro Quassinoids and Cytotoxic Antitumor Activity of the Hydrogenation Products
Authors: Imamura Kazunori , Fukamiya Narihiko , Okano Masayoshi , Tagahara Kiyoshi , Lee Kuo-Hsiung
Published: July 2006

Two new types of quassinoids (1a, 1b, 2a, 2b, 3a, and 3b) were obtained by the catalytic hydrogenation of dehydro quassinoids [dehydrobruceantin (1), dehydrobruceantinol (2), and dehydrobruceantarin (3)] which were isolated from Brucea antidysenterica. Compounds 1a and 2b showed potent selective cytotoxicity against human medulloblastoma TE-671. Significant cytotoxicity was also demonstrated by 3a for TE-671, for murine leukemia P-388, and 2b for human melanoma RPMI-7951.
Isothiocarbamido Radicals from Thiourea: Electron Spin Resonance Spectroscopy of N-Benzylidene-t-butylamine-N-oxide and 5,5-Dimethyl-1-pyrroline-N-oxide Spin Adducts
Authors: Saha Swapan K , Greenslade David J
Published: July 2006

Amidinothio radicals, NH2(=NH)CS·, formed in the reaction of thiourea and hydrogen peroxide and trapped in aqueous solution by N-benzylidene-t-butylamine-N-oxide (PBN) and 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) spin traps are reported for the first time. Stability of the radical is highly dependent on the pH as well as the concentration of thiourea. ESR spectral lines give aN and aβH values as 1.53 mT and 0.24 mT respectively for PBN and 1.46 mT and 2.08 mT respectively for DMPO spin adducts. Preliminary kinetic experiments on the spin trapping reaction are also reported.
Abundance of Cadmium in Paleozoic Limestones in Japan
Authors: Aizawa Shoichi , Akaiwa Hideo
Published: July 2006

Cadmium is significantly enriched in Paleozoic (Permian and Carboniferous) limestones in Japan. The geometric mean of Cd in these limestone samples (n = 111) is 0.57 ppm, which is an order of magnitude higher than that of Quaternary ones. Most of divalent heavy metals in these limestones exist in accessory minerals such as silicates, whereas Cd is contained in calcite. Submarine volcanoes which were active during Paleozoic period might be responsible for the high Cd content of Japanese limestones of this age.
Crystal Structures and Magnetic Properties of Binuclear Copper(II) Complexes with Alkoxo and Benzoato or Silanecarboxylato Bridges
Authors: Kawata Takashi , Yamanaka Michinari , Ohba Shigeru , Nishida Yuzo , Nagamatsu Megumi , Tokii Tadashi , Kato Michinobu , Steward Omar W
Published: July 2006

The crystal structures of the binuclear copper(II) complexes [Cu2(L-ac)(PhCOO)] (1), [Cu2(L-ac)(2-Me–PhCOO)·1/2MeOH (2), [Cu2(L-ac)(2,6-Me2–PhCOO)] (3), [Cu2(L-ac)(2,6-Cl2-PhCOO)]·0.7DMF (4), and [Cu2(L-ac)(Ph2MeSiCOO)] (5) were determined by X-ray diffraction. The ligand H3(L-ac) is a 1 : 2 Schiff base derived from 1,3-diaminopropan-2-ol and acetylacetone. These complexes are antiferromagnetic and their −2J values are (1) 183, (2) 188, (3) 133, (4) 207, and (5) 95 cm−1, respectively. A rough positive correlation between the Cu···Cu distance and the −2J value was observed except for 5. The smaller −2J value of the triorganosilanecarboxylato complex, 5, than the benzoato complexes, 1–4, indicates a stronger orbital countercomplementary effect in 5. The geometrical parameters in the benzoato bridge have a minor effect on the magnitude of the antiferromagnetic interaction.
ESR Spectra and Electronic States of 1,10-Phenanthroline Radical Anions
Authors: Koizumi Terutake , Yokoyama Yukihiro , Morihashi Kenji , Nakayama Mitsunobu , Kikuchi Osamu
Published: July 2006

The ESR spectra of the radical anions of 2,9- and 5,6-dimethyl-1,10-phenanthrolines have shown that these radical anions are in the 2B1 state, as is the unsubstituted 1,10-phenanthroline radical anion. MO calculations have indicated that the two lower electronic states of these radical anions, 2B1 and 2A2, lie close to each other, and that the relative stability is largely affected by an interaction with the counter cation.
A Facile Generation and Stereoselective Cycloaddition Reactions of 5,6-Dihydro-5,6-bis(methylene)-2,4(1H,3H)-pyrimidinedione Intermediate
Authors: Yasue Nobuyuki , Ishikawa Sei-ichi , Noguchi Michihiko
Published: July 2006

The treatment of 5-formyl-1,3,6-trimethyl-2,4(1H,3H)-pyrimidinedione (1) with a magnesium salt and DBU in dichloromethane gave the corresponding magnesium dienolate. The dienolate underwent [4+2] cycloaddition reaction with olefinic dienophiles in highly regio- and stereoselective manners.
The Palladium–Catalyzed Cross-Coupling Reaction of Enol Acetates of α-Bromo Ketones with 1-Alkenyl-, Aryl-, or Alkylboron Compounds; A Facile Synthesis of Ketones and Their Enol Acetates
Authors: Abe Shigeru , Miyaura Norio , Suzuki Akira
Published: July 2006

The synthesis of stereodefined enol acetates of ketones is readily accomplished by palladium–catalyzed cross-coupling reaction between alkyl-, aryl-, or 1-alkylboron reagents with enol acetates of α-bromo ketones. Hydroboration of alkene with 9-BBN, followed by coupling with (Z)-2-ethoxy-1-bromoethene gives the enol ether of aldehyde. These enol acetates and ethers are readily deprotected to give corresponding ketones and aldehydes in high yields.
Crystal Structures of Acrylamide Derivatives : N-t-Butylacrylamide, N-t-Butylmethacrylamide, Dimorphs of N-Phenylmethacrylamide, and N-o-Chlorophenylmethacrylamide
Authors: Kashino Setsuo , Iwamoto Tetsuyuki , Yamamoto Etsuko , Shiraga Tsuyoshi
Published: July 2006

The crystal structures of N-t-butylacrylamide, N-t-butylmethacrylamide, dimorphs of N-phenylmethacrylamide, and N-o-chlorophenylmethacrylamide have been determined by X-ray diffraction method. In all these crystals the molecules related by a glide plane are held together by an N–H···O hydrogen bond between the amide groups. The difference in the reactivity of the N-arylmethacrylamides in γ-ray induced solid-state polymerization is ascribed to the difference in an intermolecular steric effect for the molecular movement, but not to the difference in the hydrogen-bond type.