Structural chemistry of subvalent oxo- and nitrdiometalates: chemical twinning of ionic and metallic building units

低价化合物在固态化学中占有特殊的地位。离子和金属键合的贡献是实现在他们以独特的方式。结构单元可以被认为是从（间）金属相的切口，与离子结构的图案周期性地交替，并形成有序的晶格。因此，低价化合物是固体，其中以金属键为主的区域与以离子键为主的区域共存。根据结构单元的两种不同性质，低价化合物联合收割机结合了金属和离子固体的典型行为。低价化合物显示出整体良好的金属的导电性，但从离子区域的局部库仑电位的传导电子的相互作用，导致有趣的新的效果。金属和离子性质的意外组合可以前瞻性地导致新材料。金属导电性和电性的结合。G.局部化的磁性过渡金属中心可产生用于电子或数据存储装置的感兴趣的材料。修改离子和金属结构区域的体积分数可以使低维金属导体甚至小的、不相互作用的原子的原子团的量子点的合理设计成为可能。强各向异性的光学材料也是可能的，但对低价化合物固态化学的这些方面的系统研究却很少。这类物质的第一个代表是碱金属的低氧化物和重碱土金属的低氮化物。我们成功地拓宽了低价化合物的家族，合成了碱金属suboxidates和第一碱土subnitrididates含有复杂的，四面体的氧代和nitrididates阴离子，并通过表征新的结构family.This项目的目的是在suboxo和subnitrididates类的系统扩展和新的代表性的性质的表征。通过比较尽可能多的低价金属化合物的实例，可以更深入地了解离子和金属结构亚基之间的相互作用及其对宏观性质的影响。基于电导率、热容、磁化率的测量结合电子结构的量子化学计算，将建立低价化合物的结构-性质关系的全面图景。

Subvalent compounds hold a special position within solid state chemistry. Ionic and metallic bonding contributions are realised within them in a unique manner. Structural units which can be regarded as cut-outs from (inter-)metallic phases alternate periodically with motifs from ionic structures and form an ordered crystal lattice. Subvalent compounds thus are solids in which areas with perdominantly metallic bonding coexist with areas in which ionic bonding prevails. According to the two different characters of the structural building units, subvalent compounds combine the typical behaviour of metals and ionic solids. Subvalent compounds show overall good metallic behavour but interaction of the conduction electrons with the local Coulomb potentials from the ionic regions lead to interesting new effects. Unexpected combinations of metallic and ionic properties can prospectively lead to novel materials. The combination of metallic conductivity and e. g. ocalised magnetic transition metal centres could result in matierals of interest for electronic or data storage devices. Modifying the volume fraction of ionic and metallic structural areas could enable the rational design of low-dimensional metallic conductors or even quantum dots of small, not interacting atomic groups of atoms. Also strongly anisotropic optical materials are conceivable.Systematic work on these aspects of the solid state chemistry of subvalent compounds is scarce. The first representatives of this class of substances were the alkali metal suboxides and he subnitrides of the heavy alkaline earth metals. We succeeded in broadening the family of subvalent compounds by synthesising alkali metal suboxometalates and the first alkaline earth subnitridometalates containing complex, tetrahedral oxo- and nitridometalate anions and by characterising new structural families.This project aims at a systematic expansion of the classes of suboxo- and subnitridometalates and the characterisation of the properties of new representatives. By comparing as many individual examples of subvalent metalates as possible a ddeper insight for the interaction of ionic ande metallic structural subunits and its influence on macroscopic properties may be gained. A comprehensive picture of the structure-property relations of subvalent compounds based on measurements of electric conductivity, heat capacity, magnetic suscebility in combination with quantum chemical calculations of the electronic structure is to be established.