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641.
Copolymer-pendant Ru(bpy)32+ grafted onto silk fibroin was prepared by at first grafting copoly(4-methyl-4′-vinyl-2,2′-bipyridine - methylmethacrylate) onto non-woven silk fabric, and then by reacting the grafted sample with cis-Ru(bpy)2Cl2. Photoluminescence of this silk-poly Ru complex and its quenching by oxygen were studied in gas, methanol and water phases. The relative emission intensity and the emission lifetime of the silk-poly Ru showed that there are two kinds of sites for the Ru complex. The major, longer lifetime component (1070 ns, 77.1%, under Ar gas) is considered to be surrounded by polymer matrices, and the minor, shorter one (288 ns, 22.9%) seems to be exposed and is subjected to concentration quenching. The shorter lifetime species are quenched by oxygen more effectively than the longer ones. The mechanism of the quenching by oxygen and its application to oxygen sensor were discussed. 相似文献
642.
Dr. Chao Wan Gui Li Jiapei Wang Prof. Lixin Xu Prof. Dang-guo Cheng Prof. Fengqiu Chen Prof. Yusuke Asakura Dr. Yunqing Kang Prof. Yusuke Yamauchi 《Angewandte Chemie (International ed. in English)》2023,62(40):e202305371
Ammonia borane (AB) is a promising material for chemical H2 storage owing to its high H2 density (up to 19.6 wt %). However, the development of an efficient catalyst for driving H2 evolution through AB hydrolysis remains challenging. Therefore, a visible-light-driven strategy for generating H2 through AB hydrolysis was implemented in this study using Ni−Pt nanoparticles supported on phosphorus-doped TiO2 (Ni-Pt/P-TiO2) as photocatalysts. Through surface engineering, P-TiO2 was prepared by phytic-acid-assisted phosphorization and then employed as an ideal support for immobilizing Ni−Pt nanoparticles via a facile co-reduction strategy. Under visible-light irradiation at 283 K, Ni40Pt60/P-TiO2 exhibited improved recyclability and a high turnover frequency of 967.8 mol molPt−1 min−1. Characterization experiments and density functional theory calculations indicated that the enhanced performance of Ni40Pt60/P-TiO2 originated from a combination of the Ni−Pt alloying effect, the Mott–Schottky junction at the metal-semiconductor interface, and strong metal-support interactions. These findings not only underscore the benefits of utilizing multipronged effects to construct highly active AB-hydrolyzing catalysts, but also pave a path toward designing high-performance catalysts by surface engineering to modulate the electronic metal-support interactions for other visible-light-induced reactions. 相似文献
643.
Akiya Ogawa Noriaki Takami Masahito Sekiguchi Noboru Sonoda Toshikazu Hirao 《Heteroatom Chemistry》1998,9(6):581-584
Elemental sulfur can be reduced to the corresponding thiolate anion species (S2− and S2−2) selectively by samarium diiodide in the presence and absence of HMPA, respectively. The subsequent alkylation of the thiolate anion species provides a useful synthetic route to dialkyl sulfides and disulfides. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9: 581–584, 1998 相似文献
644.
Toshifumi Satoh Tomoko Imai Yoshikazu Kitajyo Takahiro Maeda Atsushi Narumi Harumi Kaga Noriaki Kaneko Toyoji Kakuchi 《Macromolecular Symposia》2004,217(1):39-46
The thermally induced cationic polymerizations of 1,6-anhydro-β-D -glucopyranose ( 1a ), 1,6-anhydro-β-D -mannopyranose ( 1b ) and 1,6-anhydro-β-D -galactopyranose ( 1c ) as a latent cyclic AB4-type monomer were carried out using (S-2-butenyl)tetramethylenesulfonium hexafluoroantimonate ( 2 ) as an initiator. The solution polymerization in propylene carbonate proceeded without gelation to produce the water-soluble hyperbranched polysaccharides ( 3a-c ) with controlled molecular weights and narrow polydispersities. The degree of branching (DB), estimated by the methylation analysis of 3a-c , was in the range of 0.38 – 0.49. The thermally induced cationic polymerization of 1a-c using 2 is a facile method leading to a hyperbranched polysaccharide with a high DB value. 相似文献