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51.
Polymeric pendant Ru(bpy)_3~(2+) complexes were prepared from homopolymer and copolymers of 4-methyl-4'-vinyl-2,2'-bipyridine (Vbpy). Vbpy was prepared from 4-methylpyridine. The comonomers were styrene (St), acrylic acid (AA), N-vinylpyrrolidone (Pyr), 4-vinylpyridine (Vpy), methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA), acrylonitrile (AN) and N-ethyl-4-vinylpyridium bromide (EQ-Vpy). The fraction of the pendant Ru(bpy)_3~(2+) repeating unit in the polymeric complex was 0.022 to 0.052. Absorption maximum, molar extinction coefficient, emission maximum and relative emission intensity of the polymeric complexes were studied. 相似文献
52.
Sigenari Suzuki Masabumi Yamaguchi Masao Onda Takesffi Sakaizumi Osamu Ohashi Ichiro Yamaguchi 《Journal of Molecular Structure》1981,73(1):41-47
Microwave spectra of thionyl chloride, SO35Cl2 and SO35Cl37Cl, in the frequency range 8–25 GHz have been analyzed. The rotational constants have been obtained from the low J transition frequencies. The rS coordinates of Cl atoms and the ro structure have been evaluated with some assumptions: r(S-O) = 1.435 ± 0.011± Å, r(S—Cl) = 2.072 0.005 Å, ∠ OSCl = 108.00 ± 0.06°, ∠ ClSCl = 97.15 ± 0.30°. Nuclear quadrupole coupling constants have been obtained for the SO35Cl2, species: xaa = ?25.02 ± 0.04 MHz, x(bb = ?0.25 ± 0.04 MHz, Xcc = 25.27 ± 0.08 MHz, and Xzz = ?96.75 MHz. The values obtained are compared with those of other workers. 相似文献
53.
Masao Kato 《Journal of polymer science. Part A, Polymer chemistry》1969,7(8):2405-2410
Solution polymerizations of o-, m- and p-hydroxystyrene with boron trifluoride etherate were investigated. The results of infrared and ultraviolet spectroscopic investigations of the polymers thus obtained indicate that p-hydroxystyrene polymer consisted mainly of the structure formed through the normal vinyl polymerization mechanism, whereas o- and m-hydroxystyrene polymers contained considerable portions of the structures due to the reaction of the vinyl group with the phenol nucleus. The rate of polymerization and the intrinsic viscosity of the polymer decreased in the order p-hydroxystyrene ? o-hydroxystyrene > m-hydroxystyrene. It was of interest that on the cationic polymerization only p-hydroxystyrene gave polymer of high molecular weight. Plausible polymerization mechanisms were considered. Solid-state polymerization of p-hydroxystyrene at solid carbon dioxide temperature with the use of boron trifluoride etherate was also investigated. Appreciable polymerization occurred only at fairly high catalyst concentrations. 相似文献
54.
Masao Nohara Masaki Hasegawa Hatsuhiko Harashina Yoichi Iitaka 《Journal of polymer science. Part A, Polymer chemistry》1988,26(10):2695-2704
Photoreactive polyamides having m- or 1 -type cyclobutane moiety were prepared via a topochemical photodimerization of 4-(3-oxo-3-phenyl-1-propenyl)benzoic derivatives,4 followed by polycondensation of cyclobutane dicarboxylate derivatives with diamines. From the spectral studies of resulted polyamides compared with the corresponding reference diamides, it was concluded that both types of polyamides were depolymerized photochemically to give the same type of amide derivative having chalcone moiety with a small amount of undefined side reaction. The cyclobutane ring of the m-dimer from 4-(3-oxo-3-phenyl-1-propenyl)benzoic acid in crystal is severely twisted presumably because of the enhanced steric repulsions between two pairs of adjacent substituents. The higher quantum yield of the m-dimer for the photocleavege, compared with that of the 1 -dimer, has been interpreted in terms of such steric repulsions by the strained structure of the m-dimer. 相似文献
55.
Masaru Yoneyama K. D. Athula Kuruppu Masa-Aki Kakimoto Yoshio Imai 《Journal of polymer science. Part A, Polymer chemistry》1988,26(11):2917-2922
Aromatic polyamides (aramids) having inherent viscosities of 0.5–1.10 dL/g were prepared by the direct polycondensation of 1,1,3-trimethyl-3-(4-carboxyphenyl)indane-5-carboxylic acid with various aromatic diamines using triphenyl phosphite and pyridine as the condensing agents. Copolyamides were also prepared by a similar procedure from a mixture of the phenylindane diacid, terephthalic acid, and p-phenylenediamine. Almost all of the aramids were soluble in a variety of solvents such as N-methyl-2-pyrrolidone, pyridine, and m-cresol, and afforded transparent and tough films by the solution casting. These aramids and copolyamides had glass transition temperatures in the range of 290–355°C, and started to lose weight at 340°C in air. 相似文献
56.
Hwa-Jin Jeong Yoshiyuki Oishi Masa-Aki Kakimoto Yoshio Imai 《Journal of polymer science. Part A, Polymer chemistry》1990,28(12):3293-3301
A new highly phenylated heterocyclic diamine, 3,4-bis(4-aminophenyl)-2,5-diphenylfuran, was synthesized in three steps from 4–-nitrodeoxybenzoin. The low temperature solution polycondensation of the diamine with various aromatic diacid chlorides afforded tetraphenylfuran-containing aromatic polyamides with inherent viscosities of 0.2–0.8 dL/g. Copolyterephthalamides were obtained from the diamine and 4,4′-oxydianiline. The polyamides were generally soluble in a wide range of solvents that included N,N-dimethylacetamide, N-methyl-2-pyrrolidone, pyridine, and m-cresol. Glass transition temperatures of the polyamides and copolyamides ranged from 302–342°C, and 10% weight loss was observed above 480°C in nitrogen. 相似文献
57.
Metallic Na formation in/on NaCl crystals with irradiation by electron or vacuum ultraviolet photons
Shigehiro Owaki Shigeko Koyama Masao Takahashi Masao Kamada Ryouichi Suzuki 《Radiation Physics and Chemistry》1997,49(6):609-615
Metallic Na was formed in/on NaCl single crystals by irradiating them with a variety of radiation sources, namely, 21 MeV electron pulses, an electron beam of 30 keV and photon fluxes in the VUV region. The physical states were analysed using several methods, optical absorption, lifetime measurement of positron annihilation, Auger electron spectroscopy and UV photoelectron spectroscopy. Metallic Na was obtained in different physical states; clusters were formed in bulk, thin layers (islands) and thick layers on the surface. 相似文献
58.
Ooi T Takahashi M Yamada M Tayama E Omoto K Maruoka K 《Journal of the American Chemical Society》2004,126(4):1150-1160
A series of (2,7-disubstituted-1,8-biphenylenedioxy)bis(dimethylaluminum) (2) has been readily prepared in situ by treatment of the requisite 2,7-disubstituted-1,8-biphenylenediol (1) with Me3Al (2 equiv) in CH2Cl2 at room temperature; this primarily relies on the successful establishment of a new synthetic procedure of 1 starting from inexpensive m-anisidine. Evaluation of 2 as a bidentate organoaluminum Lewis acid has been performed by the reduction of ketonic substrates using Bu3SnH as a hydride source in comparison to the conventional monodentate Lewis acid dimethylaluminum 2,6-xylenoxide (11), uncovering the significantly high activation ability of 2 toward carbonyl. Particularly, (2,7-dimethyl-1,8-biphenylenedioxy)bis(dimethylaluminum) (2a) exerted the highest reactivity, which has also been emphasized in the Mukaiyama aldol reaction. The structure of the bidentate Lewis acid 2 was unambiguously determined by single-crystal X-ray diffraction analysis of 2g possessing a bulky 3,5-di-tert-butylphenyl substituent, revealing the rigid dimeric assembly in the solid state. The double electrophilic activation of carbonyl substrate by 2a has been supported by low-temperature 13C NMR analysis as well as theoretical study using the Gaussian 98 program. Moreover, unique stereoselectivity has been observed in the 2a-promoted Mukaiyama Michael addition, and highly chemoselective functionalization of carbonyl compounds in the presence of their acetal counterparts has been realized using 2a. Finally, the effectiveness of 2a for the activation of ether functionality has been demonstrated in the Claisen rearrangement of allyl vinyl ethers. 相似文献
59.
Haruhiko Watanabe Masao Murano 《Journal of polymer science. Part A, Polymer chemistry》1971,9(4):911-918
The γ-ray induced polymerizations of α-chloroacrylic acid, mp 66°C, and α-bromo-acrylic acid, mp 72°C, were investigated in the temperature range from 35°C to 85°C. An analysis of polymerization kinetics was made, and results were similar to those reported in the literature for other vinyl monomers. On heating of the polymer obtained, elimination of hydrogen halide takes place, and intramolecular lactone formation is observed. The rate of lactone formation of poly(α-chloroacrylic acid) obtained in the solid-state polymerization was found to be higher than that in the liquid state, because a highly isotactic configuration of polymers, tends to be formed in the solid-state polymerization, and elimination of hydrogen chloride is facilitated with an isotactic 52 helix structure. 相似文献
60.
Yoshio Imai N. N. Maldar Masa-Aki Kakimoto 《Journal of polymer science. Part A, Polymer chemistry》1984,22(12):3771-3778
New soluble aromatic polyazomethines with inherent viscosities of 0.4–0.8 dL/g were prepared by the solution polycondensation of 2,5-bis(4-aminophenyl)-3,4-diphenylthiophene, bis(4-aminophenyl) ether, and aromatic dialdehydes in o-chlorophenol at 20°C. The copolyazomethines are generally soluble in chlorinated hydrocarbons, amide-type or phenolic solvents. The thermal stability of the polymers, which showed no weight loss up to 400°C in both air and nitrogen atmospheres. 相似文献