Niedrige Valenz und Gemischtvalenz Lanthanoid Komplexe: Reaktivität und Katalyse

本文旨在发展苄基镧系化合物化学。重点是中性均配双苄基-Ln（II）和三苄基-Ln（III）配合物的合成和结构表征。在我们的初步研究中，我们分离和结构表征了第一个同配型Ln（II）-苄基，并成功地发现了简单的合成路线（o-Me 2N-C6 H4 CH 2）3 Y（III）和（o-Me 2N-C6 H4 CH 2）3La（III），它们被证明是同构的。由于这些高活性的苄基镧系元素是合成镧系元素催化剂的潜在前体，我们希望扩大我们在这一领域的努力。我们特别感兴趣的均配苄基镧系配合物的合成，这是不稳定的吸电子基团在苄基碳，也不包含分子内的路易斯碱。我们的部分研究包括对苄基镧系元素络合物的分解反应的研究，以及分离可溶性定义明确的镧系元素-亚苄基的挑战，这些亚苄基可以进行结构研究。这组化合物仍然是未知的，但可能显示出有趣的反应性和催化活性。这些研究的第三部分包括苯乙烯聚合与Ln（II）-苄基，部分可从我们的初步研究，部分将在本项目内准备。用这些系统获得的聚苯乙烯的出乎意料的高间同立构规整度（r = 95%）要求在该领域中进一步研究活动。我们特别致力于活性和间规苯乙烯聚合，这将使热塑性材料具有更高的性能。

The present proposal aims at the development of benzyllanthanide chemistry. Emphasis is on the syntheses and structural characterization of neutral homoleptic bis-benzyl-Ln(II) and trisbenzyl-Ln(III) complexes. In our preliminary investigations we isolated and structurally characterized the first homoleptic Ln(II)-benzyls and successfully found simple synthetic routes to (o-Me2N-C6H4CH2)3Y(III) and (o-Me2N-C6H4CH2)3La(III) which were shown to be isostructural. Since these highly reactive benzyllanthanides are potential precursors in the syntheses of lanthanide catalysts, we would like to expand our efforts in this area. We are especially interested in the syntheses of homoleptic benzyllanthanide complexes, that are not stabilized by electron-withdrawing groups at the benzylic carbon and also do not contain an intramolecular Lewis-base. Part of our research includes studies on the decomposition reactions of benzylic lanthanide complexes and the challenge to isolate soluble well-defined lanthanide-benzylidenes that could be structurally investigated. This group of compounds is still unknown, but could show interesting reactivity and catalytical activity. The third part of these studies encompass styrene polymerization with Ln(II)-benzyls that are partly available from our preliminary research and partly will be prepared within this project. The unexpected high syndiotacticity (r = 95 %) of the polystyrene obtained with these systems calls for further research activity in this area. We especially aim at a living and syndiotactic styrene polymerization, which would give access to thermoplastic materials with enhanced properties.