XAS Characterization of the Novel Pressure-Formed AuF8Xe11 Solid

Fluorine's unparalleled reactivity enables the stabilization of elements in unconventional oxidation states, exemplified by compounds such as AuF5 (gold in +5) and (Xe2F11)+(AuF6)- (gold and xenon in +6). High-pressure conditions amplify this potential, allowing the synthesis of exotic materials that challenge conventional chemistry. Our recent synchrotron single-crystal X-ray diffraction experiments revealed the formation of the novel compound AuF8Xe11 near 50 GPa, with gold potentially reaching the unprecedented +8 oxidation state. This proposal aims to use XANES and EXAFS measurements on ID24-DCM to directly measure and determine the oxidation states of Au and Xe as well as the Au- and Xe-F interatomic distances in this compound near 50 GPa. This will provide the unambiguous determination of the chemical nature of the exotic AuF8Xe11 solid.

氟（Fluorine）凭借其无与伦比的反应活性，可使元素以非常规氧化态稳定存在，代表性化合物包括五氟化金（AuF5，金为+5价）以及二氙十一氟合六氟金酸盐[(Xe₂F₁₁)⁺(AuF₆)⁻，金与氙均为+6价]。高压条件可进一步放大这一反应潜能，助力合成挑战传统化学认知的新奇材料。我们近期开展的同步辐射单晶X射线衍射（synchrotron single-crystal X-ray diffraction）实验发现，在约50吉帕斯卡（GPa）的压力下生成了新型化合物AuF8Xe11，其中金可能达到前所未有的+8氧化态。本研究提案拟利用ID24-DCM光束线开展X射线吸收近边结构（X-ray Absorption Near Edge Structure, XANES）与扩展X射线吸收精细结构（Extended X-ray Absorption Fine Structure, EXAFS）测试，直接测定该化合物在50 GPa压力下金、氙的氧化态，以及Au-F、Xe-F的原子间距离，从而明确阐明这种新奇AuF8Xe11固体的化学本质。