Pushing the Boundaries of Supraicosahedral Heteroborane Chemistry: New Supraicosahedral Carboranes and Metallacarboranes

突破二十面体杂硼烷化学的界限：新的二十面体碳硼烷和金属碳硼烷

基本信息

批准号：
EP/E02971X/1
负责人：
Alan Welch
金额：
$ 64.41万
依托单位：
Heriot-Watt University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2007
资助国家：
英国
起止时间：
2007 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FE02971X%2F1
关键词：
Pushing Boundaries Supraicosahedral Heteroborane Chemistry

项目摘要

This research is concerned with the preparation of large cluster molecules, mainly of boron atoms but also carbon and metal atoms as well. Boron cluster chemistry is dominated by molecules with only 12 atoms in the cluster / the icosahedron / of which there are thousands of known examples. In contrast there are probably less than 200 such clusters with 13 atoms, only a handful with 14 atoms, and, until very recently, no such clusters with 15 atoms, and nothing larger. This is unfortunate as several of the actual and potential applications of such clusters, including their use in catalysis and in tumour therapy, would be enhanced if larger compounds could be made, particularly if more boron atoms could be incorporated.The biggest obstacle to the preparation of these large supraicosahedral boron clusters is that once you get beyond the icosahedron the atoms in the cluster have to make more bonds to their neighbours than they can comfortably do. However, previous theoretical work has suggested that this may only be an issue for 13, 14 and 15-vertex compounds, and that for those clusters with 16 or more vertices, shapes can be adopted which avoid this problem. One of the major aims of the proposed work is to try to get to 16 vertices and beyond (we are currently only one vertex away from this) to see what actually happens.The way we will make the supraicosahedral molecules is by a technique know as polyhedral expansion , a two step process in which we first open up the cluster by adding 2 electrons then add the additional atom to recluse the cage. Even though boron is uncomfortable in making many bonds in supraicosahedral clusters we can still prepare and study such compounds by adding transition metal atoms instead of boron, because metals are significantly larger than boron. Part of our intended strategy, then, is deliberately to use transition metal vertices to learn more about these unusual molecules, and to help us discover ways to ultimately make the same compounds with boron. A halfway-house would be to use main group metals, which have characteristics between those of boron and transition metals, and we also propose to research in this area.Most of the planned work is concerned with preparing new clusters and determining their structures. But in addition we are also planning to study aspects of this area computationally, with the ultimate hope of being able to establish a set of working rules, both to help us understand the experimental results retrospectively and to help us establish useful protocols that will guide future experimental work.

这项研究涉及大型簇分子的制备，主要是硼原子，但也是碳和金属原子。硼簇化学由簇 /二十面体中仅12个原子的分子主导，其中有成千上万的已知实例。相比之下，可能有13个原子，只有14个原子的200个这样的簇，直到最近才有15个原子的这样的簇，也没有什么更大的。这是不幸的，因为这样的簇的几种实际和潜在的应用，包括它们在催化和肿瘤疗法中的使用，如果可以制造较大的化合物，尤其是如果可以纳入更多的硼原子，则可以增强。舒适地做。但是，以前的理论工作表明，这可能仅是13、14和15 vertex化合物的问题，并且对于那些具有16个或更多顶点的群集，可以采用避免此问题的形状。 One of the major aims of the proposed work is to try to get to 16 vertices and beyond (we are currently only one vertex away from this) to see what actually happens.The way we will make the supraicosahedral molecules is by a technique know as polyhedral expansion , a two step process in which we first open up the cluster by adding 2 electrons then add the additional atom to recluse the cage.即使硼在上群簇中建立许多键不舒服，我们仍然可以通过添加过渡金属原子而不是硼龙来准备和研究此类化合物，因为金属比硼龙大得多。因此，有意使用过渡金属顶点有意了解有关这些异常分子的更多信息，并帮助我们发现最终与硼制成相同化合物的方法。中途将是使用主要集体金属，这些金属具有在硼和过渡金属之间具有特征的特征，我们还建议在该领域进行研究。大多数计划的工作都涉及准备新的簇并确定其结构。但是，此外，我们还计划在计算上研究该领域的各个方面，最终希望能够建立一系列工作规则，以帮助我们回顾性地了解实验结果，并帮助我们建立有用的协议，以指导未来的实验工作。