检索结果-南通市图书馆

Organocatalytic stereoselective cationic polymerization of vinyl ethers by employing a confined BrΦnsted acid as the catalyst

引用

Science China Chemistry 2022年第2期65卷 304-308页

作者： Zan Yang Xun Zhang Yu Jiang Qiang Ma Saihu Liao Key Laboratory of Molecule Synthesis and Function Discovery(Fujian Province University) State Key Laboratory of Photocatalysis on Energy and EnvironmentCollege of ChemistryFuzhou UniversityFuzhou 350108China Beijing National Laboratory for Molecular Sciences Beijing 100190China

The properties of poly(vinyl ether)s(PVEs)are highly dependent on their tacticity,and the appealing thermoplastics features of isotactic PVEs have drawn considerable efforts to develop stereoselective cationic polymerization methods to access this class of ***,reported methods that could achieve a high degree of tacticity control are limited to process employing metal-based Lewis acids,and with various limitations on catalyst loading,monomer scope,***,we introduce a metal-free stereoselective cationic polymerization of vinyl ethers by employing a class of chiral confined Br?nsted acids,imidodiphosphorimidates(IDPis),as the *** organocatalytic approach features its metal-free conditions,high efficiency,high stereoselectivity,single catalyst system,operation simplicity,etc.

关键词： organocatalysis stereoselective polymerization tacticity vinyl ethers BrΦnsted acids

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synthesis of pyrrolidinyl-ethylene fluorenyl rare-earth metal complexes and catalysis for 2-vinylpyridine polymerization

引用

Journal of Rare Earths 2023年第3期41卷 381-387,I0003页

作者： Yinjun Wang Hao Jiang Huifei Wang Zehuai Mou Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province School of Material Science and Chemical EngineeringNingbo UniversityNingbo 315211China

The metathesis reaction between pyrrolidinyl-ethylene fluorenyl lithium salts with in situ prepared cationic rare-earth metal dialkyl species[Ln(CH_(2)SiMe_(3))_(2)(THF)_(x)][BPh_(4)]afford efficiently the corresponding constrained-geometry complexes L^(1)Ln(CH_(2)SiMe_(3))_(2)(L^(1)=FluCH_(2)CH_(2)NC_(4)H_(8),Ln=Y(1a),Lu(1b),Sc(1c))and L^(2)Ln(CH_(2)SiMe_(3))_(2)(L^(2)=(2,7-di-tert-butyl)FluCH_(2)CH_(2)NC_(4)H_(8),Ln=Y(2a),Lu(2b),Sc(2c))in good *** these complexes were characterized by NMR spectroscopy,and the solid-state molecular structure of yttrium complex 1a was defined with single-crystal X-ray diffraction *** catalytic performance of these complexes towards 2-vinylpyridine polymerization was investigated,where these complexes alone can efficiently promote the polymerization of 2-vinylpyridine giving isotactic poly(2-vinylpyridine).Upon the activation with[Ph_(3)C][B(C_(6)F_(5))_(4)],the yttrium and lutetium complexes also afford isotactic poly(2-vinylpyridine),while the scandium complexes produce syndiotactic poly(2-vinylpyridine).

关键词： Rare-earth metal Constrained-geometry complex 2-Vinylpyridine stereoselective polymerization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

polymerization of rac-Lactide Catalyzed by Lanthanum Complexes Containing a Chiral N Atom

Polymerization of rac-Lactide Catalyzed by Lanthanum Complex...

引用

中国化学会第28届学术年会

作者： Yuee Chen1,Mei Wang1,*,Peili Zhang1,Xiuna Wang1,Yu Wang1,Licheng Sun1,2 1State Key Laboratory of Fine Chemicals,DUT-KTH Joint Education and Research Center on Molecular Devices,Dalian University of Technology(DUT),Dalian,116012,China 2Department of Chemistry,Royal Institute of Technology(KTH),Stockholm,10044 Sweden

＜正＞Development of Lewis acid catalysts for controlled polymerization of lactide（LA） is a lasting interest over past two decades as polylactide is a biodegradable and biocompatible polyester derived from bio-renewable feed stocks. The stereoregular polylactide with improved physical and mechanical properties is an attractive polymeric material of high quality.A promising and practical strategy for the convenient production of the stereoregular PLA is the

关键词： lactide lanthanum complex N2O2 ligand stereoselective polymerization

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：