Synthesis, Reactivity and Catalysis of New Metallacarborane complexes

新型金属碳硼烷配合物的合成、反应性和催化

• 批准号: 1940024
• 金额: --
• 依托单位: University of Bath
• 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-1940024
• 关键词: Synthesis; Reactivity; Catalysis; New; Metallacarborane

Carboranes, boranes and metallacarboranes have interesting structures and have been at the forefront of the development in new insights and fundamental understanding of bonding throughout chemistry. This project is concerned with the synthesis and chemical properties of new early transition/lanthanide element and main group element metallacarboranes. This project will pursue studies in three specific areas; In the first of these studies we wish to develop main group carborane derivatives, with an emphasis on reactivity relationships aimed at a greater understanding of the chemistry of these unusual compounds. Of particular interest is the chemistry of novel group 13/14 main group element complexes, as well as exploration of potential applications of these and related carborane derivatives in catalysis. The second category of studies is focused on an effort to synthesize new high oxidation state early transition element and lanthanide element derivatives of the metallacarborane type, which bear subtle resemblance to known imido and cyclopentadienide complexes. Some of the new materials which will be synthesized are expected to have interesting physical properties possibly including desirable electronic and/or spectral properties, and some will be useful precursors for the synthesis of interesting materials. Despite many of these systems having been known for some time, exploitation of this chemistry wrt the formation of metal amides, metal alkyls and metal hydrides is amazingly underdeveloped. Even starting form known materials we have the opportunity to develop remarkable complexes the reactivity of which has never been explored and is ripe for development. Figure 1 shows one possible route to the development of a Ti(IV) system incorporating a dicarboloide ligand and two amide groups this {Ti(dicarbollide)} fragment, or Cuckoo complex, has the potential to act as a surrogate earth abundant metal such as Ca and hopefully displaying similar reactivitys to real complexes such as Ca(HMDS)2 and Ca(CH{SiMe3}2)2, both of which have shown application in a range of catalytic applications including, but not limited to, polysilazane synthesis, catalytic hydroamination, and catalytic hydroboration. Hoverer unlike a naked Ca ion the metal dicarbollide fragment can be further tuned by augmentation of the B and c substituents on the coordinating face of the dicarbollide, such that stabilising groups which provide electron density to the system may be incorporated. Thirdly, as part of our study we propose to investigate the use of heterometallic systems supported by the dicarbollide ligand. We will form bi-metallic complexes in which the exo-metal will display a synergistic effect on these complexes modifying their reactivity and enhancing activity, and just as the Ae element can be changed (group 13 & Ln elemental are also of interest) the group 1 metal can be changed from Li to Na, K, Rb etc. or non-coordinating cations such as PPN (Ph3P=N=PPh3).The metal carborane clusters studied in this research may have potential applications in catalysis, and molecular electronics. The project incorporates a strong emphasis on synthesis, characterization of new complexes which align to a number of the strategic themes of the department/university and EPSRC, making it an excellent project for training students.

碳硼烷、硼烷和金属碳硼烷具有有趣的结构，并且在整个化学键合的新见解和基本理解方面一直处于发展的前沿。该项目涉及新型早过渡/镧系元素和主族元素金属碳硼烷的合成和化学性质。该项目将在三个具体领域进行研究；在第一项研究中，我们希望开发主族碳硼烷衍生物，重点是反应性关系，旨在更好地了解这些不寻常化合物的化学性质。特别令人感兴趣的是新型 13/14 主族元素配合物的化学，以及探索这些和相关碳硼烷衍生物在催化中的潜在应用。第二类研究的重点是合成新的高氧化态早期过渡元素和金属碳硼烷类型的镧系元素衍生物，它们与已知的亚氨基和环戊二烯配合物具有微妙的相似性。一些将要合成的新材料预计具有有趣的物理性质，可能包括所需的电子和/或光谱性质，并且一些将是用于合成有趣材料的有用前体。尽管这些系统中的许多系统已为人所知已有一段时间，但令人惊讶的是，利用这种化学方法来形成金属酰胺、金属烷基化物和金属氢化物却尚未开发。即使从已知材料开始，我们也有机会开发出卓越的复合物，其反应性从未被探索过，并且开发的时机已经成熟。图 1 显示了开发包含二碳内酯配体和两个酰胺基团的 Ti(IV) 系统的一种可能途径，该 {Ti(dicarbollide)} 片段或 Cuckoo 络合物有潜力充当地球丰富金属（如 Ca）的替代品，并有望表现出与真实络合物（如 Ca(HMDS)2 和 Ca(CH{SiMe3}2)2）类似的反应性，这两种络合物均已表明 在一系列催化应用中的应用，包括但不限于聚硅氮烷合成、催化氢胺化和催化硼氢化。与裸露的Ca离子不同，金属二碳内酯片段可以通过增加二碳内酯配位面上的B和c取代基来进一步调节，从而可以掺入为系统提供电子密度的稳定基团。第三，作为我们研究的一部分，我们建议研究由二碳内酯配体支持的异金属系统的使用。我们将形成双金属配合物，其中外金属将对这些配合物表现出协同效应，改变其反应性并增强活性，正如 Ae 元素可以改变一样（第 13 族和 Ln 元素也很重要），第 1 族金属可以从 Li 变为 Na、K、Rb 等或非配位阳离子，如 PPN (Ph3P=N=PPh3)。 这项研究可能在催化和分子电子学方面具有潜在的应用。该项目非常重视新综合体的综合和表征，这些综合体与系/大学和 EPSRC 的许多战略主题相一致，使其成为培训学生的优秀项目。