Towards the Mechanism(s) of Early Transition Metal Promoted Selective Olefin Oligomerisation Catalysis - Synthesis, Spectroscopic and XAFS Studies

早期过渡金属促进选择性烯烃低聚催化的机制 - 合成、光谱和 XAFS 研究

• 批准号: EP/F032463/1
• 负责人: John Evans
• 金额: $ 78.35万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF032463%2F1
• 关键词: Towards; Mechanism; Early; Transition; Metal

The quest for more highly selective, cleaner and more efficient catalysts e.g for olefin trimerisation or tetramerisation remains a high priority for the chemical industry. Achieving these targets demands a detailed understanding of the catalytic cycle(s) and the nature of the active species. Characterisation of the individual stages in a homogeneous catalytic cycle is not easily achieved since the active species are likely to be highly reactive and often very transient, making their crystallographic characterisation highly unlikely. Furthermore, for the paramagnetic e.g. Cr-based catalysts NMR spectroscopy is not informative. Under this project we will develop and use a unique freeze-quench cell to allow the transient and active species to be trapped at various selected stages through the cycle, allowing in situ spectroscopic analysis by extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) spectroscopy techniques. We will prepare and characterise a series of related metal complexes based on Cr, Mo and Sc in the presence of a selected set of N-, S-, N/S- and N/P-donor ligands, including complexes of the industrially important NH(CH2CH2Sdecyl)2 and iPrN(PPh2)2. Using a range of techniques (UV-visible, EPR, 45Sc NMR spectroscopy), in conjunction with XAFS and XANES data using the set-up described above, we will probe in detail the oxidation state and structures at various stages through the activation and catalysis to provide a much more detailed understanding of the mechanisms at work. We also expect to demonstrate the potential of the new rapid (millisecond) freeze-quench XAFS/XANES approach much more widely to provide key information regarding other homogeneous catalysis systems.

寻求更高选择性、更清洁和更高效的催化剂（例如用于烯烃三聚或四聚的催化剂）仍然是化学工业的首要任务。实现这些目标需要详细了解催化循环和活性物质的性质。均相催化循环中各个阶段的表征并不容易实现，因为活性物质可能具有高反应性并且通常非常短暂，使得它们的晶体学表征极不可能。此外，对于顺磁性，例如Cr 基催化剂的 NMR 光谱无法提供信息。在该项目下，我们将开发和使用独特的冷冻猝灭池，以允许瞬态和活性物质在循环的各个选定阶段被捕获，从而允许通过扩展 X 射线吸收精细结构 (EXAFS) 和 X 射线进行原位光谱分析。 -射线吸收近边结构（XANES）光谱技术。我们将在一组选定的 N-、S-、N/S- 和 N/P- 供体配体存在下制备并表征一系列基于 Cr、Mo 和 Sc 的相关金属配合物，包括工业上重要的配合物NH(CH2CH2S癸基)2和iPrN(PPh2)2。使用一系列技术（UV-可见光、EPR、45Sc NMR 光谱），结合使用上述设置的 XAFS 和 XANES 数据，我们将通过活化和催化详细探测各个阶段的氧化态和结构提供对工作机制的更详细的了解。我们还希望更广泛地展示新的快速（毫秒）冷冻淬灭 XAFS/XANES 方法的潜力，以提供有关其他均相催化系统的关键信息。

项目成果

Activation of [CrCl 3 {PPh 2 N( i Pr)PPh 2 }] for the selective oligomerisation of ethene: a Cr K-edge XAFS study

[CrCl 3 {PPh 2 N( i Pr)PPh 2 }] 的活化用于乙烯的选择性低聚：Cr K 边缘 XAFS 研究

• DOI: http://dx.10.1039/c6cy00902f
• 发表时间: 2016
• 期刊: Catalysis Science & Technology
• 影响因子: 5
• 作者: Bartlett S

Catalysis seen in action.

催化在起作用。

• DOI: http://dx.10.1098/rsta.2013.0152
• 发表时间: 2015
• 期刊: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
• 作者: Tromp M

Insights in the mechanism of selective olefin oligomerisation catalysis using stopped-flow freeze-quench techniques: A Mo K-edge QEXAFS study

使用停流冷冻骤冷技术选择性烯烃低聚催化机制的见解：Mo K-edge QEXAFS 研究

• DOI: http://dx.10.1016/j.jcat.2011.10.015
• 发表时间: 2011
• 期刊: Journal of Catalysis
• 影响因子: 7.3
• 作者: Bartlett S

Activation of [CrCl 3 {R-SN(H)S-R}] Catalysts for Selective Trimerization of Ethene: A Freeze-Quench Cr K-Edge XAFS Study

用于乙烯选择性三聚的 [CrCl 3 {R-SN(H)S-R}] 催化剂的活化：冷冻淬灭 Cr K-Edge XAFS 研究

• DOI: http://dx.10.1021/cs501017g
• 发表时间: 2014
• 期刊: ACS Catalysis
• 影响因子: 12.9
• 作者: Bartlett S

Sc(III) complexes with neutral N3- and SNS-donor ligands--a spectroscopic study of the activation of ethene polymerisation catalysts.

Sc(III) 与中性 N3 和 SNS 供体配体的配合物 - 乙烯聚合催化剂活化的光谱研究。

• DOI: 10.1039/c2dt31804k
• 发表时间: 2013-01-16
• 期刊: Dalton transactions
• 影响因子: 4
• 作者: Stuart A. Bartlett;G. Cibin;A. Dent;J. Evans;Martin J. Hanton;G. Reid;R. Tooze;M. Tromp
• 通讯作者: M. Tromp