Niedrige Valenz und Gemischtvalenz Lanthanoid Komplexe: Reaktivität und Katalyse

低价和混合价稀土配合物：反应性和催化作用

• 批准号: 23794324
• 负责人: Professor Dr. Sjoerd Harder
• 金额: --
• 依托单位: Lehrstuhl für Anorganische und Metallorganische Chemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/23794324?language=en
• 关键词: Niedrige; Valenz; und; Gemischtvalenz; Lanthanoid

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.

本提案旨在发展苄基镧系化学。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，我们分离并表征了第一个同配型 Ln(II)-苄基，并成功找到了 (o-Me2N-C6H4CH2)3Y(III) 和 (o-Me2N-C6H4CH2)3La(III) 的简单合成路线，它们被证明是同构的。由于这些高反应性的苄基镧系元素是合成镧系元素催化剂的潜在前体，我们希望扩大在这一领域的努力。我们对均配型苄基镧系络合物的合成特别感兴趣，该络合物不受苄基碳上的吸电子基团稳定，也不包含分子内路易斯碱。我们的部分研究包括对苄基镧系元素络合物分解反应的研究，以及分离可进行结构研究的可溶性明确的镧系元素-亚苄基的挑战。这组化合物仍然未知，但可能表现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与 Ln(II)-苄基的聚合，部分可从我们的初步研究中获得，部分将在本项目中准备。用这些系统获得的聚苯乙烯出人意料的高间同立构规整度（r = 95%），需要在这一领域进行进一步的研究活动。我们特别致力于活性和间同立构苯乙烯聚合，这将有助于获得具有增强性能的热塑性材料。