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151.
Akasaka T Kono T Takematsu Y Nikawa H Nakahodo T Wakahara T Ishitsuka MO Tsuchiya T Maeda Y Liu MT Yoza K Kato T Yamamoto K Mizorogi N Slanina Z Nagase S 《Journal of the American Chemical Society》2008,130(39):12840-12841
We report here the results on single crystal X-ray crystallographic analysis of the Gd@C82 carbene adduct (Gd@C82(Ad), Ad = adamantylidene). The Gd atom in Gd@C82(Ad) is located at an off-centered position near a hexagonal ring in the C2v-C82 cage, as found for M@C82 (M = Sc and La) and La@C82(Ad). Theoretical calculation also confirms the position of the Gd atom in the X-ray crystal structure. 相似文献
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The orientation, surface and optical properties of sol-gel derived Y2O3 films have been investigated. Transparent Y2O3 films were prepared on quartz glass substrates by sol-gel processes using YCl3·6H2O as a starting material. The water droplet contact angles of the films reached constant values between 79° and 90° after the films were left for 8 to 10 days in air at ambient temperature, indicating that the film surface exhibited hydrophobicity. When 2-(2-methoxyethoxy)ethanol (MEE) was added to the sol, yttria in the films crystallized to a strongly oriented cubic phase at firing temperatures between 400°C and 500°C. The intensity of the XRD peaks increased as the firing temperature was increased to 900°C. However, yttria crystallized to a non-oriented cubic phase when MEE was not used. The refractive index and packing density of the Y2O3 films increased from 1.55 to 1.68 and from 0.67 to 0.79, respectively, as the firing temperature was raised from 400°C to 900°C, indicating that sol-gel derived Y2O3 films are lower in density than evaporated ones. 相似文献
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Kiyoharu Nishide Shogo Ichihashi Hiroyuki Kimura Takahiro Katoh Manabu Node 《Tetrahedron letters》2001,42(52):9237-9240
The endo/exo selectivities of Diels–Alder reactions of N-protected pyrroles with allene-1,3-dicarboxylates were studied under Lewis acid assisted and thermal reaction conditions. A novel attractive effect between the N-protective carbonyl group of pyrrole and the ester group of allene-1,3-dicarboxylates operates to control the selectivity in the above Diels–Alder reaction. This new attractive effect to give the exo adduct is more effective than the Alder orbital effect. 相似文献
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Hiroyuki Nishide Hiroyoshi Kawakami Eishun Tsuchida Yoshimi Kurimura 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10-11):1339-1348
Polymeric benzenetricarbonylchromium complexes were synthesized by radical copolymerization of benzyl acrylatetricarbonylchromium with styrene and by reaction of (dimethylaminobenzene)tricarbonylchromium with poly(styrene-co-acrylic acid). The polymeric chromium complexes give transparent films and on UV irradiation under nitrogen lead to dinitrogen complexes of the corresponding polymeric dicarbonylchromium. The reversible coordination of dinitrogen was confirmed by IR and visible absorption spectroscopy. A predominant feature of the polymeric dinitrogen complexes is their extraordinarily high stability in air compared with the corresponding low molecular analogs. The effect of polymer matrices on dinitrogen coordination is discussed. 相似文献
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