Dinuclear Pentacoordinated Organoyttrium Biphenolates as Initiators for the Synthesis of High-Molecular Weight Isotactic Poly(2-vinylpyridine).
Dinuclear Pentacoordinated Organoyttrium Biphenolates as Initiators for the Synthesis of High-Molecular Weight Isotactic Poly(2-vinylpyridine).
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DOI：
10.1021/acs.inorgchem.9b02385
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发表时间：
2019-10
影响因子：
4.6
通讯作者：
M. Oishi;Reiji Yoshimura;N. Nomura
中科院分区：
文献类型：
--
作者：
M. Oishi;Reiji Yoshimura;N. Nomura
Dinuclear organoyttrium biphenolato complexes have been synthesized for the first time starting from Y(CH2SiMe3)3(THF)2 and readily available biphenols with bulky substituents at the 3,3'-positions. XRD analysis revealed that these complexes are formed as homochiral dimers even though racemic biphenols were employed. Such dinuclear penta-coordinated yttrium complexes were evaluated as initiators in the polymerization of 2-vinylpyridine (2-VP). High activity and excellent isotacticity (mm > 99%) were observed. DSC analysis of poly(2-VP) showed a Tm = 221 °C, which is the highest value reported to date. Attempts to improve the low initiation efficiency of the present system were made by co-use with several organo-main-group metal reagents. Specifically, good molecular weight control within the high Mn region was achieved by the addition of Et3Al (Al/Y = 10).
