bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Synthesis of 7α-Methoxycephalosporins through Selenenamides
Authors: Kobayashi Takeo , Hiraoka Tetsuo 
Published: July 2006

Abstract
The o-nitrobenzeneselenenamides were oxidized with active manganese dioxide to give the irnines, which were converted to the 7α-methoxycephalosporins 3 by the reaction with lithium methoxide. The selenenamides 3 were acylated with phenoxyacetyl chloride to afford the desired cephamycin derivatives 4 via tertiary amide 5, which was not isolable. This methoxylation reaction was also carried out in penicillin series to give the desired 6α-methoxypenicillin 8 although the ring opening compound 9 was a major product. The difference between sulfenamides and selenenamides in their acylation reactions was discussed.
Reactions of 1-Halo-1-nitroso- and 1-Halo-1-nitrocycloalkanes with Triphenylphosphine. A New Synthesis of Lactam
Authors: Sakai Ikuo , Kawabe Norio , Ohno Masaji 
Published: July 2006

Abstract
Reactions of 1-halo-1-nitroso- and 1-halo-1-nitrocycloalkanes with triphenylphosphine have been carried out. The Perkov reaction and Beckmann rearrangement occurred successively with the formation of lactams in high yields. The reaction of cycloalkanone oxime with halogen in the presence of triphenylphosphine also gave lactams in one step.
1,3-Dipolar Cycloadditions to 2-Phenyl-1-azaspiro[2.2]pent-1-ene
Authors: Tsuge Otohiko , Watanabe Hiroyuki , Kiryu Y\={o}ko 
Published: July 2006

Abstract
Benzonitrilium-p-nitrobenzylide undergoes 1,3-dipolar cycloaddition to highly strained 2-phenyl-1-azaspiro[2.2]pent-1-ene, yielding the cycloadduct which is thermally converted to the dihydrobenzo[f]quinazoline and pyrimidine. In the reaction with α,N-diarylnitrone, the spiroazapentene gives 1-(benzylideneamino)-1-(N-phenylbenzamido)cyclopropane arising from the initial cycloadduct.
Stereochemistry of Diels-Alder Reactions at High Pressure. II. Influence of High Pressure on Asymmetric Induction in Condensation of (−)-Di-(R)-menthyl Fumarate with Butadiene and Isoprene
Authors: Jurczak Janusz 
Published: July 2006

Abstract
The high-pressure Diels-Alder condensation of (−)-di-(R)-menthyl fumarate with butadiene and isoprene, followed by reduction of the adducts with lithium aluminium hydride, produced (1S,2S)-(+)-4-cyclohexene-1,2-dimethanol and (1S,2S)-(+)-4-methyl-4-cyclohexene-1,2-dimethanol in 6.2–12.8% optical yield, depending on the pressure applied. Results of asymmetric synthesis were discussed in light of the concept of parallel transition states. An interpretation of the thermal and Lewis-acid-catalyzed asymmetric Diels-Alder condensations using (−)-di-(R)-menthyl fumarate was proposed.
SO2-Produced Acidic Hydroxyl Groups and the Catalytic Activities of Alkaline Earth X Zeolites
Authors: Otsuka Kiyoshi , Wada Yuji , Tanaka Kimiaki , Morikawa Akira 
Published: July 2006

Abstract
The generation of Brönsted acid sites by SO2-adsorption on alkaline earth X zeolites has been examined by infrared spectroscopy. The SO2-induced catalytic activities of the zeolites in the double-bond isomerization of butenes can be ascribed to both the increase in the number of acidic hydroxyl groups and the enhancement in the catalytic activities of the groups after the SO2 adsorption.
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

Abstract
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&gt;Bg·HCl&gt;Bg·HBr&gt;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

Abstract
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).
On the Magnetic Susceptibility of Interacting Spin-pair Systems
Authors: Ohya-Nishiguchi Hiroaki 
Published: July 2006

Abstract
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&lt;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&lt;κ≤2, they can be characterized by a broad maximum and a transition to the antiferromagnetically ordered state. For κ&gt;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&lt;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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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&gt;kCHP&gt;kBKP, and the equilibrium constants in the order KCHP&gt;KBHP&gt;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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.