Novel pathways to nitridophosphate networks

该项目侧重于以协同方法合成和分析(氧)硝基磷酸盐网络结构及其变体。通常，在探索性合成的非均相产品中，新化合物被发现为微晶副相。电子结晶学和同步加速器微焦点衍射有助于它们的鉴定。中间化合物也以同样的方式表征，并暗示了反应途径。在此基础上，针对物相纯产物的合成进行了优化。对(氧)硝基磷酸盐结构化学的扩展及其在极端条件下的固相反应形成机理的阐明是本论文的重点。探索性的高温高压合成、前驱体路线及其组合是本项目的起点。还研究了多砧法的反应中所用矿化剂的作用。此外，还需要合成和表征混合的硝酸磷-硅酸盐。除了氮化和歧化反应外，预先组织的分子前驱体路线是一种很有前途的方法。将研究中间形成的氮化物玻璃的析晶行为。亚稳微晶相可作为合成新型氮化物网络的前驱体。该项目进一步侧重于表征(氧代)硝酸磷酸盐的高压相和PON本身。异相产物和少数相用电子结晶学进行鉴定，并对其结构进行表征。电子衍射层析成像、透射电子显微镜和X射线衍射与同步辐射相结合等强有力的方法被用来精确测定微米到纳米晶体的结构。复杂氮化物结构经常表现出真实结构效应，这可以通过STEM-HAADF、高分辨率EDX和EELS映射以及扩散散射的表征来分析。捕获中间体的表征为理解形成机理提供了重要信息。因此，可以优化合成路线，以获得物相纯的产品。他们的潜在属性，如离子导电性或类似沸石的行为，将在合作中进行研究。此外，计划对特别有趣的氮化物结构进行理论计算(DFT)。总而言之，该项目将有效地将雄心勃勃的合成与现代结构分析方法相结合，以识别和获得具有挑战性的氮化物网络结构。

The project focuses on a synergistic approach toward the synthesis and structural analysis of (oxo)nitridophosphate network structures and variants thereof. Typically, new compounds are discovered as microcrystalline side phases in heterogeneous products of explorative syntheses. Electron crystallography and synchrotron microfocus diffraction help for their identification. Intermediate compounds are characterized in the same way and hint at reaction pathways. Based on this, syntheses are optimized aiming at phase pure products. Both the extension of (oxo)nitridophosphate structural chemistry as well as the elucidation of their mechanisms of formation in solid-state reactions under extreme conditions are targeted. Explorative high-temperature and high-pressure syntheses, precursor routes and their combinations are the starting point of this project. Reactions with the multianvil method are also examined with regard to the role of the mineralizing agents used therein. Beyond this, mixed nitridophosphate-silicates are to be synthesized and characterized as well. In addition to nitridation and metathesis reactions, pre-organized molecular precursor routes represent a promising approach. The crystallization behavior of intermediately formed nitride glasses will be investigated. Metastable microcrystalline phases can be used as precursors leading to novel nitride networks. The project further focuses on characterizing high-pressure phases of (oxo)nitridophosphates and PON itself. Heterogeneous products and minority phases are to be identified by electron crystallography and are structurally characterized. Powerful methods such as electron diffraction tomography and the combination of TEM and X-ray diffraction with synchrotron radiation are employed for precise structure determination of micro- to nano-crystalline compounds. Complex nitride structures frequently exhibit real-structure effects which are analyzed using STEM-HAADF, high-resolution EDX and EELS mapping as well as the characterization of diffuse scattering. The characterization of trapped intermediates provides essential information concerning the understanding of formation mechanisms. Thus, synthetic routes can be optimized to obtain phase pure products. Their potential properties such as ionic conductivity or zeolite-like behavior will be examined in cooperation. In addition, theoretical calculations (DFT) of particularly interesting nitride structures are planned. In conclusion, this project will efficiently combine ambitious syntheses with modern methods of structural analysis in order to identify and access challenging nitride network structures.