Stable Unsaturated Silicon Clusters (Siliconoids)

不饱和硅团簇是气相沉积硅的中间产物。这些短暂物种的稳定衍生物被认为嵌入非晶硅中。在分子形式中，它们通过空间要求高的取代基的存在而动力学稳定。特别值得注意的是具有两个未取代顶点的Si 6 R6衍生物，其构成了全局最小结构，因此是苯的高能硅类似物。这种明显的偏好促使我们为这类新化合物引入一个明确的平凡名称：benzpolarene.中心目标是硅的功能化，包括掺入异质元素，如体硅的经典掺杂剂（硼和磷），但也包括其他第14族元素和过渡金属。合适的官能度将允许根据目标性质从两种可能的选项中有意地选择：簇核心的膨胀或在硅化物的外围中所需元素的附接。我们的目标是建立一个包含不同大小此类物种的综合工具箱，使我们能够将适当的同核和异核类硅化合物连接到我们选择的底物上。有了各种各样的制备方法，我们将能够利用苯并环芳烃和其他稳定的硅化合物的独特的电子，磁性和光电性能，通过（a）它们作为一种新的非常富电子的配体类用于均相催化和（B）它们作为材料中的功能基序的应用。在子项目（a）中，我们将专注于地球上丰富的贱金属的催化作用，因为我们预计，硅的显着电子过剩将导致非无辜的行为，作为配体，应该表现在支持两个电子的氧化还原步骤，否则不受3d金属的青睐。目标物种将使人想起硅表面上的过渡金属，从而作为多相催化的分子模型系统。前所未有的富硅配位环境对性能的影响将被用作这些配体系统的微调的手柄。在分项目（B）中，将开发一种处理硅质材料的真实的自下而上的方法。我们将从功能化的硅化物和合适的连接单元开始制备一维，二维或三维的纳米结构材料，并研究它们的相互连接和硅化物的电子通信所带来的协同效应。总的来说，该项目旨在缩小分子硅化学和硅体化学之间的概念差距-其应用几乎涉及现代社会的所有领域。

Unsaturated silicon clusters (siliconoids) are intermediates of the deposition of silicon from the gas phase. Stable derivatives of these ephemeral species are thought to occur embedded in amorphous silicon. In molecular form they are kinetically stabilized by the presence of sterically demanding substituents. Of particular note is the Si6R6 derivative with two unsubstituted vertices, which constitutes the global minimum structure and therefore the energetic silicon analogue of benzene. This pronounced preference prompted us to introduce an unambiguous trivial name for this new class of compounds: benzpolarene.The central objective is the functionalization of siliconoids including the incorporation of heteroelements such as the classical dopants for bulk silicon (boron and phosphorus), but also other Group 14 elements and transition metals. Suitable functionalities will allow for deliberately choosing from two possible options as a function of the targeted properties: either the expansion of the cluster core or the attachment of the desired element in the periphery of siliconoids. We aim to establish a comprehensive toolbox of such species in variable sizes that will enable us to tether the appropriate homo- and heteronuclear siliconoids to the substrate of our choice. Armed with a broad variety of preparative methods, we will then be able to exploit the unique electronic, magnetic and optoelectronic properties of benzpolarenes and other stable siliconoids by (a) their use as a new extremely electron-rich ligand class for homogeneous catalysis and (b) their application as functional motifs in materials. In subproject (a), we will focus on catalysis with earth-abundant base metals as we anticipate that the pronounced electron surplus of the siliconoids will lead to a non-innocent behavior as ligands that should be manifest in the support of two-electron redox steps otherwise not favored by 3d metals. The targeted species will be reminiscent of transition metals on silicon surfaces and thus serve as molecular model systems for heterogeneous catalysis. The influence of the unprecedented silicon-rich coordination environments on the performance will be used as a handle for the fine-tuning of these ligand systems. In subproject (b), a real bottom-up approach towards siliconoid materials will be developed. We will prepare nanostructured materials in one, two or three dimensions starting from functionalized siliconoids and suitable linking units and investigated them for cooperative effects brought about by the interlinkage and thus electronic communication of siliconoids. Overall, the project aims to close conceptual gaps between molecular silicon chemistry and that of the silicon bulk – with its applications in virtually all areas of modern society.