Structure Determination of Tetranitromethane, C(NO2)4, in the Solid and Gaseous Phases

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We propose to study the structure of tetranitromethane (C(NO2)4, TNM) in the solid state and the gas phase. TNM is not only a ternary substance, it is the parent molecule for organic nitro materials and thus of fundamental interest. Earlier studies have given partly inconclusive results concerning its structure. In the solid state different phases exist, but the structures have not been solved probably due to molecular dynamics and/or disorder. Earlier vibrational spectroscopy results point to dynamics behaviour in the solid high temperature phase (above -98°C).In the gas phase, two attempts of gas electron diffraction have provided only a partial description of the experimental scattering intensities. A simple description of the experimental results by a quantum-chemically calculated structure of S4 symmetry is not satisfying. We want to circumvent the earlier experimental problem by applying different crystallization techniques in order to gain crystals for X-ray diffraction that lead to resolvable structures in the solid state and to explore the experimental gas phase by new electron diffraction experiments and analysis with a sophisticated dynamic description of the molecules. The preparation of suitable samples will be performed in Munich, the structural chemistry experiments will be carried out in the core facility GED@BI (Centre of Gas Electron Diffraction and Small Molecule Structures) in Bielefeld. The results promise to provide a deeper under¬standing for the reactivity and behaviour of TNM and can be model the understanding of the structure, reactivity and chemical behaviour and their mutual relationships of highly nitrated compounds.