Novel pathways to nitridophosphate networks

该项目侧重于（氧）氮化磷酸酯网络结构及其变体的合成和结构分析的协同方法。通常，新化合物是在探索性合成的非均相产物中以微晶侧相的形式发现的。电子晶体学和同步加速器微聚焦衍射有助于它们的鉴别。中间化合物以同样的方式表征，并提示反应途径。在此基础上，针对相纯产物进行了优化合成。目的是扩展（氧）氮磷结构化学以及阐明其在极端条件下固相反应中的形成机制。探索性高温高压合成、前驱体路线及其组合是本项目的出发点。用多砧法进行的反应也考察了其中所使用的矿化剂的作用。除此之外，还将合成混合氮磷硅酸盐并对其进行表征。除氮化和复分解反应外，预组织分子前体途径是一种很有前途的方法。研究中间形成的氮化玻璃的结晶行为。亚稳微晶相可以作为形成新型氮化物网络的前驱物。该项目进一步侧重于表征（氧）氮磷酸盐和PON本身的高压相。异质产物和少数相用电子晶体学进行鉴定，并进行结构表征。电子衍射层析成像、透射电镜和x射线衍射结合同步辐射等强大的方法被用来精确测定微纳米晶体化合物的结构。复杂氮化物结构经常表现出实结构效应，利用STEM-HAADF、高分辨率EDX和EELS映射以及漫射散射表征对其进行了分析。圈闭中间体的表征为理解形成机制提供了重要信息。因此，可以优化合成路线以获得相纯产品。它们的潜在性质，如离子电导率或类似沸石的行为将在合作中进行研究。此外，还计划了特别有趣的氮化物结构的理论计算。总之，该项目将有效地将雄心勃勃的合成与现代结构分析方法结合起来，以识别和获取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.