Borosulphates as Host Structures for Luminescent Materials and for Non-Linear Optical Properties

硼酸盐是含有阴离子的类似硅酸盐的化合物，其由硫酸盐四面体共价结合四面体或三角形平面硼酸盐离子组成。从化学上讲，它们的行为类似于研究得相对彻底的硼磷酸盐。到目前为止，第一批发表的大约80个晶体例子证实了与硅酸盐结构的强烈相似性。这种类似硅酸盐的化合物之所以有趣，有几个原因。它们打开了一个巨大的、本身就是非常有趣的结构化学，这些新化合物为研究结构-性质关系提供了许多主题。我们的重点是寻找适合于白光发光二极管、荧光粉管、测温仪或闪烁体的新型发光化合物。此外，我们还考虑了合适候选材料的非线性光学特性，这些特性可能用于激光器的倍频。在这里，特别有趣的是化合物显示出大的带隙这就是硼酸盐的情况。其他性质，如酸碱行为以及催化性质也将被考虑。在本项目中，我们将继续对新型化合物类硼酸盐晶体进行系统的探索性研究。在这个项目中，我们将重点研究掺杂外部和内部过渡金属离子（d和f元素）的代表。我们期望除了发现新的结构特征外，还能发现异常丰富的晶体化学；在这样的结构中，它们缺乏反转对称性的可能性越来越大，从而显示出非线性光学特性——硼酸盐和四面体单元促进了这一点。我们期望对硼硫酸盐的配位行为有更深入的了解，如配体场效应和非相干效应；这将有助于基础研究以及未来可能的应用。我们将有条不紊地使用单晶x射线衍射进行结构测定。我们合成样品的纯度将被检查，新的化合物将被粉末x射线衍射鉴定。我们还将使用衍射方法和DTA/TG等经典热分析来表征新化合物的热行为。在理论计算的支持下，我们通过光谱学（荧光和紫外-可见光谱）来检验其光学性质。将对合适的化合物进行非线性光学性质的考察。特别是对非晶粉末样品，我们计划硼的m.a.s.n.m.r.测量，以确定局部结构。此外，我们计划磁测量鉴定价态和可能的磁排序。

Borosulphates are silicate-analogous compounds containing anions, which comprise sulphate tetrahedra bound covalently to tetrahedral or trigonal planar borate ions. Chemically these behave like the relatively thoroughly investigated Borophosphates. The first approximately eighty crystalline examples published so far, confirm the strong similarity to silicate structures. Such silicate-analogous compounds are interesting for several reasons. They open a great and per se highly interesting structural chemistry, and these novel compounds provide many topics for the investigation of structure-property relations. Our focus lies in the search for new luminescent compounds suited for white light emitting diodes, phosphor tubes, thermometry or as scintillators. Moreover, we consider non-linear-optical properties of suited candidates which might be employed in lasers for frequency doubling. Here, especially compounds are interesting showing large bandgaps which is the case for borosulphates. Other properties like acid-base behaviour as well as catalytic properties will be considered, too.In this project we continue the systematic and explorative investigation of the novel compound class of crystalline borosulphates. In this project we will focus on representatives doped with outer and inner transition metal ions (d and f elements). We expect besides the discovery of new structural features an extraordinarily rich crystal chemistry; in such structures the probability grows that these lack inversion symmetry and thus show non-linear optical properties – borates and tetrahedral units foster that. We expect deeper insight in the coordination behaviour of borosulphates, such as ligand-field effects and the nephelauxetic effect; this will be helpful for basic research as well as for possible future applications. Methodically we will use the single-crystal x-ray diffraction for the structure determination. The purity of our synthesised samples will be checked and new compounds will be identified by powder x-ray diffraction. We will additionally characterise the thermal behaviour of the new compounds using diffractions methods and classic thermal analysis like DTA/TG. We examine the optical properties by optical spectroscopy (fluorescence and UV-Vis-spectroscopy) supported by theoretical calculations. Suited compounds will be scrutinised regarding non-linear-optical properties. Especially on amorphous powder samples we plan boron m. a. s. n. m. r. measurements for the determination of the local structure. Moreover, we plan magnetic measurements for the identification of valence states and possible magnetic ordering.