Insertion polymerization of electron-deficient vinyl monomers

缺电子乙烯基单体的插入聚合

基本信息

批准号：
164875938
负责人：
Professor Dr. Stefan Mecking
金额：
--
依托单位：
Arbeitsgruppe Chemische Materialwissenschaft
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2010
资助国家：
德国
起止时间：
2009-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/164875938?language=en
关键词：
Insertion polymerization electron deficient vinyl

项目摘要

Catalytic polymerization of ethylene and propylene is one of the most well-studied chemical reactions. By stark contrast, an insertion polymerization of electron deficient polar-substituted vinyl monomers is a long-standing challenge. Only recently, linear copolymerizations of ethylene with a scope of monomers including even acrylic acid have been realized. In the first funding period a comprehensive picture was gained of factors governing insertion chain growth and catalyst deactivation. Catalyst design was advanced and novel polymeric materials evolved. We now focus on overcoming the identified intrinsic limitations of insertion (co)polymerization of polar vinyl monomers.Coordination of the functional group of the free monomer, and in particular of the repeat units gener¬ated by insertion, blocks coordination sites reversibly and hinders catalysis. To overcome this problem, a selective binding of the functional groups to appropriate sites in the catalyst is pursued. An interaction of functional groups of the monomer with carefully placed complementary hydrogen-bonding motifs in the bidentate ligand of neutral Pd(II) catalysts is sought to favor olefin coordination over binding of the incoming monomers functional groups. In extension of this concept also to the polar groups of already incorporated monomer, a diversion of their binding away from chelating coordination blocking the active sites is aimed for. An alternative approach to resolve this problem - potentially also providing new copolymer microstructures - is a combination of ethylene insertion chain growth with free-radical growth of polar monomer segments. Monteil (Macromolecules 2011, 44, 3293) suggested that neutral Ni(II) salicylaldiminato complexes polymerize ethylene and methyl methacrylate (MMA) to (multi)block copolymers. Our preliminary studies confirm that an insertion chain growth of ethylene and radical polymerization of MMA occur simultaneously, and both reactions are interdependent. To unravel the mechanisms operative here and devise generic concepts to insertion/radical 'shuttling' polymerizations, polymerizations with (13C labeled) Ni-aryl and Ni-methyl precursors will be pursued, combined with polymer endgroup analysis. Further, the role of the metal in generating and scavenging radicals will be illuminated by studies of (salicylaldiminato)Ni(I) species prepared for this purpose. This comprises their reactivity under polymerization conditions as well as stoichiometric reactions with the active species of insertion chain growth.Stereocontrol by space-filling repulsive interactions, established for propylene, is not applicable here. We have devised an asymmetric substitution of moderate bulk at a P-donor adjacent to the bound olefin as a concept to control acrylate insertion. This serves as a starting point to develop stereoregular chain growth via remote rigid linkers. In further course, the aforementioned concepts of attractive interactions can come into play.

乙烯和丙烯的催化聚合是研究最精心良好的化学反应之一。通过鲜明的对比，电子定义的极性取代乙烯基单体的插入聚合是一个长期的挑战。直到最近，已经实现了乙烯与包括丙烯酸在内的单体范围的线性共聚。在第一个资金期间，总体上综合了插入链生长和催化剂停用的因素。催化剂设计是先进的，新型聚合物材料也进化了。现在，我们专注于克服极地乙烯基单体的插入（CO）聚合的固有局限性。自由单体功能组的协调，尤其是插入发电的重复单元的官能群，阻止了协调位点可逆位点可逆地和后果催化。为了克服这个问题，追求官能团与催化剂中适当位点的选择性结合。在中性PD（II）催化剂的鸟类配体中，单体的官能团与精心放置的互补氢键基序的相互作用，可以感觉到有利于烯烃的配位，而不是接入单体官能团的结合。在将此概念扩展到已经掺入的单体的极地群体中，它们的结合远离螯合配位阻断了活跃位点。解决此问题的另一种方法 - 可能还提供新的共聚物微结构 - 是乙烯插入链生长与极性单体段的自由基生长的组合。 Monteil（Macromolecules 2011，44，3293）提出中性Ni（II）水杨甲米那酸络合物将聚合乙烯和甲基丙烯酸甲酯（MMA）聚合到（多）嵌段共聚物。我们的初步研究证实，乙烯的插入链生长和MMA的根本聚合发生了另一种方法，即揭示此处运行的机制，并将通用概念设计用于插入/激进的“快车”聚合，与（13c caped）Ni-Aryl和Ni-Methyl cropursors contrym copert in Comprimed comprimengecrect in Comprimen comprimengecremer comprimen in Comprimengecremer，ni-methyyy comprimen in Comprimengecremer in Comprimengecremer，合并。此外，金属在产生和清除自由基中的作用将通过为此目的准备的（含水层甲米那酸）Ni（i）种类的研究来照亮。这包括它们在聚合条件下的反应性以及与插入链生长的活性物种的化学计量反应。在这里不适用于丙烯的空间填充排斥相互作用，在这里不适用。我们已经在与结合烯烃相邻的P-Donor上设计了一种不对称的现代体积，以控制丙烯酸插入。这是通过远程刚性接头发展立体链增长的起点。在进一步的过程中，Priore关系的吸引力互动概念可以发挥作用。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Reactivity of Functionalized Vinyl Monomers in Insertion Copolymerization

DOI：
10.1021/acs.macromol.5b02749
发表时间：
2016-02
期刊：
Macromolecules
影响因子：
5.5
作者：
Nicole Schuster;Thomas Rünzi;S. Mecking
通讯作者：
Nicole Schuster;Thomas Rünzi;S. Mecking

Catalytic Chain Transfer Polymerization to Functional Reactive End Groups for Controlled Free Radical Growth

催化链转移聚合至功能性反应性端基以控制自由基生长

DOI：
10.1021/acs.macromol.0c00241
发表时间：
2020
期刊：
Macromolecules
影响因子：
5.5
作者：
Stadler;Sonja M;Göttker-Schnetmann;Amelie S;Fischer;Stephan R. R;Mecking;Stefan
通讯作者：
Stefan

Role of Radical Species in Salicylaldiminato Ni(II) Mediated Polymer Chain Growth: A Case Study for the Migratory Insertion Polymerization of Ethylene in the Presence of Methyl Methacrylate.