Activation of C-H and B-H bonds through sigma-bonding to Cobalt complexes

通过与钴络合物的 σ 键合激活 C-H 和 B-H 键

• 批准号: 1949556
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1949556
• 关键词: Activation; bonds; through; sigma; bonding

By applying knowledge gained from the extensive research into 4d and 5d metal complexes for C-H activation and dehydrocoupling of amino borane, to 3d metals, especially cobalt. A range of novel catalysts will be synthesised, characterised and used in catalysis with a focus upon dehydrocoupling and C-H activation processes and in particular the generation of sigma-alkane complexes. The use of 3d metals in these processes is relatively unexplored and offers many scientific and technological opportunities. Amine boranes have received considerable recent attention due to the range of their potential uses: as a hydrogen storage and transport vector, as precursors for ceramic BN thin-films, and as precursors to polymers with potentially interesting properties. The majority of reported catalysts for dehydrocoupling of amine boranes are based on 4d and 5d metals, with limited research addressed towards finding examples of cobalt complexes. The few cobalt examples investigated have low activity and selectivity for the polyaminoborane target product and are ill defined. By applying previous research into rhodium and iridium based catalysts to cobalt based systems new, highly active, complexes will be isolated, characterised and used in catalysis. Following this with detailed mechanistic studies will lead to insight into this previously under investigated class of catalyst. These same complexes should also display interesting behaviour in C-H activation. Due to its potential applications in the transformation of natural gas into chemical feedstocks, and in natural product synthesis, C-H activation has been the focus of extensive research. Again, most of this work has been carried out using 4d and 5d metal complexes. A focus within the Weller group has been on the isolation of the low valent sigma-alkane complexes as an intermediate in C-H activation processes. The group has carried out single-crystal solid-gas reactions which have led to the isolation of a number of rhodium based sigma-alkane complexes. Application of this same methodology to cobalt could allow the synthesis of 3d sigma-alkane complexes, which would be a significant landmark discovery in the area. This project falls within the EPSRC Physical Science research area, more specifically within the focus of catalysis. It is estimated that catalysis currently contributes over £50 billion/year to the UK economy, and further development is essential for transformation towards a sustainable society.

通过将从对氨基硼烷的 C-H 活化和脱氢偶联的 4d 和 5d 金属配合物的广泛研究中获得的知识应用于 3d 金属，尤其是钴。一系列新型催化剂将被合成、表征并用于催化，重点关注脱氢偶联和 C-H 活化过程，特别是 σ-烷烃络合物的生成。 3D 金属在这些工艺中的使用相对未经探索，但提供了许多科学和技术机会。胺硼烷由于其潜在用途广泛，最近受到了相当多的关注：作为氢储存和运输载体、作为陶瓷氮化硼薄膜的前体以及作为具有潜在有趣特性的聚合物的前体。大多数已报道的胺硼烷脱氢偶联催化剂都是基于 4d 和 5d 金属，而针对钴络合物实例的研究有限。研究的少数钴实例对聚氨基硼烷目标产物的活性和选择性较低，并且定义不明确。通过将先前对铑和铱基催化剂的研究应用于钴基系统，将分离、表征新的高活性配合物并将其用于催化。随后进行详细的机理研究将有助于深入了解之前研究的这一类催化剂。这些相同的复合物在 C-H 激活中也应该表现出有趣的行为。由于其在将天然气转化为化学原料以及天然产物合成中的潜在应用，C-H活化一直是广泛研究的焦点。同样，大部分工作都是使用 4d 和 5d 金属配合物进行的。 Weller 小组的重点是分离作为 C-H 活化过程中间体的低价 σ-烷烃配合物。该小组进行了单晶固-气反应，分离出了许多铑基σ-烷烃配合物。将同样的方法应用于钴可以合成 3d 西格玛烷烃复合物，这将是该领域的一个重大里程碑发现。该项目属于 EPSRC 物理科学研究领域，更具体地说，属于催化领域。据估计，催化目前每年为英国经济贡献超过 500 亿英镑，进一步发展对于向可持续社会转型至关重要。