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991.
Jong-Chan Lee Ikuyoshi Tomita Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1999,37(13):1979-1986
The synthesis of pyridine-containing polymers was carried out by the cycloaddition of diynes with nitriles in the presence of organocobalt complexes as catalysts. As a model experiment, the pyridine-formation reaction of monofunctional acetylenes with nitriles was reexamined in detail in the presence of organocobalt catalysts, from which the combination of terminal aliphatic acetylenes and aromatic nitriles was proved to be suitable for the specific pyridine-formation process. On the basis of this result, the polymerization of terminal aliphatic diynes with aromatic nitriles was carried out in the presence of the cobalt catalyst (10 mol %) to give polymers containing substituted pyridine moieties in the main chain in high yields. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1979–1986, 1999 相似文献
992.
993.
Emiko Koyama Fumio Sanda Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1997,35(2):345-352
Syntheses and polycondensations of optically active hydroxycarboxylic acids prepared from acid anhydrides and aminoalcohols were carried out. Novel polymers with M̄n 9900–27,200 were obtained by the polycondensations of hydroxycaboxylic acids derived from maleic or succinic acid using 1.2 eq. of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC · HCl) in DMF (2M) at room temperature for 8 h in satisfactory yields. Meanwhile, a hydroxycarboxylic acid obtained from phthalic acid afforded no polymer but a phthalimide derivative. The radical additions of ethanethiol or mercaptoethanol with the polymers derived from maleic anhydride proceeded smoothly in satisfactory incorporation ratios (65–98%), respectively. The polymer obtained from succinic anhydride and 2-aminoethanol showed hydrolytic degradability. © 1997 John Wiley & Sons, Inc. 相似文献
994.
Osamu Shimomura Toshihiko Sato Ikuyoshi Tomita Masato Suzuki Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1997,35(14):2813-2819
A monomer having dibenzothiophene moiety, 2-vinyldibenzothiophene (1), was prepared by the Ni-catalyzed cross-coupling reaction of vinyl bromide with the Grignard reagent of 2-bromodibenzothiophene. The radical homopolymerization of 1 and the copolymerization with styrene were carried out at 60°C in toluene (1.0M) for 20 h using AIBN (5 mol %) as an initiator to obtain the corresponding polymers in high yields. Thermal analyses of the copolymers showed that both 10% weight loss and glass transition temperatures increase when increasing the content of 1 unit. The monomer reactivity ratio was evaluated as r1 = 2.55 (1) and r2 = 0.16 (styrene). © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2813–2819, 1997 相似文献
995.
Fumio Sanda Toru Abe Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1997,35(13):2619-2629
Syntheses and radical polymerizations of several (meth)acrylamides having L -amino acid moieties were examined. The monomers were prepared by the reactions of L -amino acid ester hydrochlorides with (meth)acryloyl chloride in the presence of triethylamine in satisfactory yields. Radical polymerizations of the monomers were carried out in the presence of AIBN (1 mol %) in bulk and in several solvents to afford the corresponding polymers in satisfactory yield. The glass transition temperatures and specific rotations of the polymers depended on the substituents of the L -amino acid moieties. Nearly the same specific rotations were observed for the monomers and the model compounds of the polymer units, N-pivaloyl amino acid methyl esters. On the contrary, the specific rotations of the polymers shifted to the negative direction in ca. 30°. The interaction between the polymer side chains might affect the changes in the specific rotations from monomers to polymers. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2619–2629, 1997 相似文献
996.
997.
Joël Jacob Katrin Geßler Daniel Hoffmann Haruyo Sanbe Kyoko Koizumi Steven M. Smith Takeshi Takaha Wolfram Saenger 《Angewandte Chemie (International ed. in English)》1998,37(5):605-609
The cavity of the larger molecule has less space for guests! Unlike the structure of the smaller annular cyclodextrins, that of the higher homologues of cycloamyloses (CAs) with more than ten glucose units contains a 90° kink between adjacent glucose residues within one half of the molecule and a 180° band flip between adjacent units in different halves (see depicted section of the CA14 structure) to yield butterfly-shaped structures with narrow, groovelike cavities. 相似文献
998.
Naotoshi Nakashima Takeshi Tokunaga Yuko Nonaka Takashi Nakanishi Hiroto Murakami Takamasa Sagara 《Angewandte Chemie (International ed. in English)》1998,37(19):2671-2673
Two reversible one-electron transfers are observed for an electrode device made from C60 and an artificial lipid (see schematic drawing). Cyclic voltammetric studies reveal that the redox couples are unchanged even after 50 cycles, thus indicating that the C60 radical monoanion and the C60 dianion generated in aqueous solution are very stable. 相似文献
999.
Fumio Sanda Emiko Koyama Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1998,36(12):1981-1986
Synthesis and radical polymerization of a novel optically active methacrylate, (S)–2–tert–butoxycarbonylamino–3–phenylpropyl methacrylate (MA–F–BOC), were examined. MA–F–BOC was synthesized from methacrylic acid and N–protected (L)–phenylalaninol. Radical polymerization of MA–F–BOC quantitatively afforded the corresponding polymethacrylate with a relatively high molecular weight. Radical copolymerizations of MA–F–BOC were carried out with styrene and acrylamide to afford the copolymers. Radical polymerization of MA–F–BOC in the presence of n–butanethiol afforded the oligomers, whose degrees of polymerizations were 3.3–8.0. The BOC group was completely cloven with HBr to afford the corresponding optically active polymeric amine quantitatively. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 1981–1986, 1998 相似文献
1000.