AM2Net Advanced Macromolecular Materials By Transition Metal Catalysis; Group 2: "Post Metallocene Catalysis"; Functional Polyolefin Architectures via Post-Metallocene Catalysis

烯烃单体乳液聚合是最重要也是用途最广的聚合方法之一。得到了聚合物胶乳，即尺寸在50到1000 nm范围内的聚合物微粒的稳定水分散体。到目前为止，聚合物乳液在工业上完全是通过自由基工艺生产的。然而，乳液中的催化聚合正受到越来越多的关注。目前，对适合于水-烯烃聚合的特定后过渡金属络合物对水的反应性几乎没有系统的了解。重要的基本反应步骤包括：1)水和烯烃单体与金属中心的相对结合。2)金属烷基键的水解性。3)金属结合单体对水的反应性。这些反应将通过实验进行研究，特别是通过核磁共振监测以及催化齐聚和聚合反应的研究。中性镍(II)与水杨醛二胺配体的络合物，已知非常适合于合成高相对分子质量的聚乙烯分散体，以及阳离子钯二亚胺络合物，它们特别适合作为模型化合物。通过密切合作，齐格勒小组将同时对这些反应进行建模，并在实验和理论研究之间提供持续的反馈。

Emulsion polymerization of olefinic monomers is one of the most important, and also versatile polymerization processes. Polymer latices are obtained, i.e. stable aqueous dispersions of polymer microparticles in the size range of 50 to 1000 nm. To date, polymer latices are produced industrially by free radical processes exclusively. However, catalytic polymerization in emulsion is receiving strongly increased interest. Currently, little systematic knowledge of the reactivity of the particular late transition metal complexes suited for aqueous olefin polymerization towards water exists. Fundamental reaction steps of interest comprise: 1) the relative binding of water vs. olefinic monomers to the metal centers. 2) hydrolysis of metal alkyl bonds. 3) the reactivity of metal-bound monomer towards water. These reactions will be investigated experimentally, especially by NMR monitoring and by study of catalytic oligomeriation and polymerization reactions. Neutral nickel(II) complexes with salicylaldimine ligands, known to be well suited for the synthesis of high-molecular-weight polyethylene dispersions, and cationic palladium diimine complexes, which are particularly well suited as model compounds will be employed. In a close collaboration these reactions will be modelled by the Ziegler group at the same time, with a continuous feedback between experimental and theoretical studies.