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

• Applicant: Professor Dr. Norbert W. Mitzel
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2019 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 434445823

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.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Robert Wolf