Synthesis, characterization and catalytic function of a B12-hyperbranched polymer
Synthesis, characterization and catalytic function of a B12-hyperbranched polymer
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DOI：
10.1039/b923924c
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发表时间：
2010-01-01
影响因子：
4
通讯作者：
Hisaeda, Yoshio
中科院分区：
文献类型：
--
作者：
Tahara, Keishiro;Shimakoshi, Hisashi;Hisaeda, Yoshio
合成了一种由维生素B-12衍生物和超支化聚合物（HBP）组成的新型杂化催化剂，并用紫外-可见光谱、电子自旋共振（ESR）和原子力显微镜（AFM）对其进行了表征。B-12-HBP作为均相催化剂表现出良好的性能。共价固定的B-12部分被有效地溶剂化，并且钴中心可被吡啶客人接近。B-12-HBP对2-苯乙基溴表现出较高的反应活性，并在紫外光照射下，在TiO 2存在下对还原二聚反应的选择性增加。
A new hybrid catalyst composed of a vitamin B-12 derivative and a hyperbranched polymer (HBP) was synthesized and characterized by UV-vis and ESR spectroscopy as well as AFM. The B-12-HBP showed good properties as a homogenous catalyst. The covalently-immobilized B-12 moieties were efficiently solvated and the cobalt centers were accessible for pyridine guests. The B-12-HBP showed high reactivity to 2-phenethylbromide and increased selectivity for reductive dimerization in the presence of TiO2 with UV light irradiation.