Czech-German Cooperation Project: Structure studies on inner and outer functionalized icosahedral and bicapped square-antiprismatic boron clusters

这是捷克/德国联合合作项目的申请。捷克部分已由捷克科学院无机化学研究所Drahomir Hnyk博士提交给捷克科学基金会。该项目旨在确定官能化碳硼烷簇分子的结构，即官能化二碳-闭索-十硼烷（1,2-C2B8H10）和1,2-二碳-闭索-十二硼烷（1,2-C2B10H12），其中一些末端氢原子被EH单元取代（其中E = S、Se、Te）。布拉格集团将使用这些化合物作为建筑刚性构件，作为自组装单层 (SAM) 材料的一部分。了解基础分子的结构数据对于这些化合物在该领域的应用非常重要。由于化合物的结晶能力有限，通过结构化学的标准方法 X 射线衍射 (XRD) 测定此类硼簇分子的分子结构通常很困难。因此，我们希望为此目的应用气体电子衍射（GED）并研究气态分子未受扰动的结构。比勒费尔德集团是全球为数不多的运行 GED 设备的中心之一。除了纯结构测定之外，这些化合物还是进一步开发 GED 数据分析新策略的理想候选化合物。这也将是该项目的一部分。这些发展旨在提高结构数据的精度、可靠性和可重复性。我们小组中的 Vishnevskiy 博士提出的这种新的细化策略，通过一整套计算约束在最小二乘细化过程中使用正则化，并允许调整实验数据分析中理论输入的权重。我们第一次希望将这种方法与通过微波光谱等其他方法获得的结构信息结合起来。还将尝试应用特殊形式的结晶（原位结晶）以获得适合 XRD 实验的样品。结合自由分子的气相数据，这将通过改变相来提供有关分子结构扭曲的信息。这些还可以研究功能化碳硼烷簇的电荷密度分布，从而深入了解与其在基于 SAM 的材料化学中的使用相关的进一步分子特性。

This is an application for a joint Czech/German collaboration project. The Czech part has been submitted to Czech Science Foundation by Dr. Drahomir Hnyk, Institute of Inorganic Chemistry of the Academy of Science of the Czech Republic. The project aims at the structure determination of functionalized carbaborane-cluster molecules, namely functionalized dicarba-closo-decaboranes (1,2-C2B8H10) and 1,2-dicarba-closo-dodecaborane (1,2-C2B10H12) with some of the terminal hydrogen atoms substituted by EH units (where E = S, Se, Te). These compounds will be used by the Prague group as architecturally rigid building blocks as parts of self assembled monolayer (SAM) based materials. The knowledge of structural data of the underlying molecules is of importance for the application of these compounds in this area. The determination of molecular structures of such boron-cluster molecules by the standard method of structural chemistry, X-ray diffraction (XRD), is often difficult due to limited crystallization ability of the compounds. Therefore we want to apply gas electron diffraction (GED) for this purpose and study the unperturbed structure of the molecules in the gaseous state. The Bielefeld group is one of a few centers worldwide running equipment for GED. Besides pure structure determination, these compounds are ideal candidates for further development of new strategies in GED data analysis. This will also be part of this project. These developments aim at higher precision, reliability and reproducibility of the structural data. This new refinement strategy, introduced by Dr. Vishnevskiy in our group, uses regularization during least-squares refinements by a full set of calculated restraints and allows adjusting the weight of theoretical input into analysis of experimental data. For the first time we want to combine this approach with structural information gained by other methods like microwave spectroscopy. It will also be tried to apply specialized forms of crystallization (in-situ crystallization) to obtain suitable specimen for XRD experiments. In combination with gas-phase data of free molecules this will give information on the molecular structure distortions by changing the phase. These will also allow studying the charge density distribution of the functionalized carborane clusters, and consequently gaining insight into further molecular properties relevant for their use in SAM-based material chemistry.