We developed and demonstrated a new method for structurally characterizing highly reactive and air-sensitive noble-gas compounds using three-dimensional electron diffraction (3D ED). We focused on compounds formed between xenon difluoride (XeF₂) and manganese tetrafluoride (MnF₄), which are challenging to study because they are both strongly oxidizing and decompose easily when exposed to air. Traditional single-crystal X-ray diffraction (SCXRD) requires relatively large, high-quality crystals, which are difficult to obtain for such reactive materials. The new approach enables crystal structure determination from nanometer-sized crystals, greatly expanding the range of compounds that can be studied.
We successfully synthesized and fully characterized three XeF₂–MnF₄ adducts: 3XeF₂·2MnF₄, XeF₂·MnF₄, and XeF₂·2MnF₄. We developed a low-temperature sample handling and transfer procedure that allowed these sensitive compounds to be loaded into a transmission electron microscope for 3D ED analysis without decomposition. The crystal structures determined by 3D ED were found to be in excellent agreement with those obtained by SCXRD on larger crystals and with theoretical models from density functional theory (DFT) calculations. This confirms the reliability and accuracy of 3D ED for studying even the most challenging reactive noble-gas compounds. The results also provide new insights into the structural diversity and bonding in xenon–metal fluoride systems, which are important for understanding the chemistry of noble gases.
The FZÚ team performed all electron diffraction analyses and developed the method to make the electron diffraction experiments possible.
