Structure Determination of Di-tert-butyldiphosphatetrahedrane in the Solid and Gas Phases

本文拟对小笼状化合物二叔丁基二磷酸四面己烷的固相和气相结构进行研究。该化合物是由Prof. Wolf， Regensburg小组制备和鉴定的，但由于其低熔点和在-20°C以下分解的倾向，到目前为止还不可能生长出适合x射线衍射的单晶。该化合物具有重要的意义，因为它是一种简单的杂四面体，其分子式介于极张力的四叔丁基四面体（CCMe3）4和白磷P4的球形芳香分子之间。因此，这两者之间的键合情况必须有适当的实验结构数据来分类。在比勒菲尔德的核心设施GED@BI（气体电子衍射和小分子结构中心）内，我们将(a)尝试通过原位方法结晶标题化合物，确定其晶体结构，(b)如果晶体质量允许，尝试使用高角度衍射确定电荷密度。(c)利用气体电子衍射测定了自由分子的气相结构；(d)计算了P4、P3（CCMe3）、P2(CCMe3)2、P(CCMe3)3和（CCMe3）4系的磁感应环电流的大小和拓扑结构。合成部分将在雷根斯堡进行，结构化学实验在比勒费尔德进行。

We propose to study the structure of the small cage compound di-tert-butyldiphosphatetrahedrane in the solid and gaseous phases. The compound was prepared and identified in the group of Prof. Wolf, Regensburg, but it was so far not possible to grow single crystals suitable for X-ray diffraction due to its low melting point and its tendency for decomposition below -20°C. The compound is of fundamental interest because it is a simple hetero-tetrahedrane with a formula between the extremely strained tetra-tert-butyltetrahedrane (CCMe3)4 and the spherically aromatic molecules of white phosphorus P4. The bonding situation must therefore between these two and needs proper experimental structure data to be classified. Within the core facility GED@BI (Centre of Gas Electron Diffraction and Small Molecule Structures) in Bielefeld we will (a) attempt to crystallize the title compound by in situ methods determine its crystal structure, (b) attempt to determine the charge density using high-angle diffraction if crystal quality allows this, (c) determine the gas phase structure of the free molecules by means of means of gas electron diffraction and (d) calculate the magnitude and topology of magnetically induced ring currents for the series P4, P3(CCMe3), P2(CCMe3)2, P(CCMe3)3 and (CCMe3)4. The synthesis part will be carried out in Regensburg, the structural chemistry experiments in Bielefeld.