Double salts with a multifunctional character made from Zintl phases and oxo- as well as halogeno-metalates

该研究项目旨在通过分子离子水平上的两个无机组分的结合，通过合成固态化学的方法来开发用于新型功能材料的基础化合物。重点放在由九个原子组成的三角体、多阴离子锗和锡团簇，它们与第二类阴离子如金属氧酸盐和金属卤化物阴离子结合形成新的混合半导体固态材料(双盐)。由于碱金属锌相和碱金属氧化物或金属卤化物的相互结构可调性，它们的结合为新的多组分杂化材料的产生和设计提供了许多可能性。由于复盐可以以可变的组成出现，因此这种化合物类具有可调带隙的潜力。这类新材料在光电子学中具有潜在的应用前景，原则上也可以作为水分解催化剂。在第一步中，基于少数已知的代表性，系统地开发了双盐的合成协议，并应用于各种其他组合。用X-射线衍射法和拉曼光谱对新化合物进行了结构表征。基本的电子性质，如带隙或磁性，组成元素的氧化状态，表明单元之间可能的电荷转移，是通过实验确定的。利用量子化学计算，一方面计算了电子结构和带隙。另一方面，根据结构关系确定具有杂化性质的稳定的、新的、未知的候选化合物，并利用理论方法对其热力学稳定性进行检验。在另一步骤中，使用所开发的合成协议来具体地合成选定的候选。具体地说，在这里申请的项目中，制备了含有作为组分1的多阴离子[Ge9]4-、[Sn9]4-和[M@Sn9]x-以及[Mo4]x-(M=过渡金属)或四面体配位的卤化物(例如[SnBr4]2-，[PbBr4]2-，[MX4]x-；X=卤素)或[MX6]x-(M=锡，铅)类型的卤化物作为组分2。这两个组分的结构单元都被称为碱金属化合物，但它们的组合在这里是第一次系统地开发。组件2今天已经被用于金属青铜和太阳能电池。这种组合能够在组件的建筑单元之间实现电荷转移过程，并实现更好的可调带隙。

This research project aims for the development of fundamental compounds for new functional materials by means of synthetic solid-state chemistry through the combination of two inorganic components at the molecular ionic level. The focus is on deltahedral, polyanionic germanium and tin clusters comprising nine atoms, that are in combination with a second type of anion such as oxometalates and metal-halide anions form new, hybrid semiconducting solid state materials (double salts). Due to their mutual structural tunability, the combination of both alkali-metal Zintl phases and alkali-metal metal-oxides or metal-halides offers numerous possibilities for the generation and design of new multi-component hybrid materials. Since double salts can appear with variable composition, this compound class has the potential for tunable band gaps. The new material class has application potential in optoelectronics and, in principle, also as a water splitting catalyst.In a first step, synthesis protocols for double salts are systematically developed based on the few known representatives and are applied to various other combinations. The new compounds are structurally characterized by means of X-ray diffraction methods and Raman spectroscopy. Basic electronic properties such as band gaps or magnetic properties, oxidation states of the constituting elements that suggest a possible charge transfer between the units, are determined experimentally. Using quantum chemical calculations, on the one hand, the electronic structures and band gaps are calculated. On the other hand, stable, new, unknown candidates with hybrid character are identified on the basis of structural relationships and tested with regard to thermodynamic stability using theoretical methods. In a further step, selected candidates are specifically synthesized using the synthesis protocols developed. Specifically, in the project applied for here, hybrid compounds are produced which contain the polyanions [Ge9]4–, [Sn9]4– and [M@Sn9] x– as component 1 and metal-oxide or metal-halide anions of the [MO4]x– (M = transition metal) or tetrahedrally coordinated halides (e.g. [SnBr4]2–, [PbBr4]2–, [MX4]x-; X = halogen) or halides of the type [MX6]x- (M = Sn, Pb) as component 2. The structural units of both components are known as alkali-metal compounds, however in combination they are systematically developed here for the first time. Component 2 is already used today in metallic bronzes and in solar cells. The combination enables charge-transfer processes between the building units of the components and better tunable band gaps.