Solid State Oxides and Oxyfluorides

基于分子组分的化学性质和功能的晶体结构的合理设计是有机固体化学中一个长期和令人兴奋的研究课题。直到最近，晶体工程才成为无机固体化学的一个新兴领域。明智地利用地球化学和环境科学文献，我们继续开发高收率反应，控制纯度，并生长缺乏反演对称性的单晶新材料。缺乏反演对称性的新材料（或非中心对称材料）是所有当前和未来基于压电、热释电和铁电的技术的基础。在过去的二十年里，许多发明都是基于非中心对称的结构。这一领域的所有未来进展都等待着新一代学生的教育，他们有能力设计和合成这种特殊的原子组合，这种组合是制造非中心对称材料所必需的。本项目旨在了解如何优化金属氧和氟氧基团的几何形状和静电势，从而在金属-氧和金属-氟键中创造有序和避免无序。氟氧化物的晶体对称性是由周围晶格提供的接触网络决定的，而这些接触网络又被有意地控制以形成手性、极性或手性极性的三维固体。非中心对称结构是指那些缺乏反演对称性的结构。在过去的二十年中，许多基于压电、热电、铁电和二次谐波产生（SHG）的发明创造了重要的当前和未来技术，缺乏反演对称性的结构是这些技术的必要条件。这些材料为与非中心对称空间群相关的基础科学研究提供了大量的新型固体。稳定、鲁棒、高性能的非线性光学材料（NLO）在微观和宏观水平上具有增强的光学性能依赖于具有偶极矩的无机材料，从而表现出很大的光学非线性。这些材料对于改变光信号的幅度、相位或频率是必不可少的。混合金属氧化物氟化物是一类具有极性和手性（有时是极性和手性的组合）结构的新型高性能无机固态材料。训练学生进行半组合合成和理论建模研究，以指导和推进我们的探索性合成计划，并获得高质量的单晶。晶体对于表现出非线性光学响应的材料的结构研究、表征和物理测量是必不可少的。

Non-technicalThe rational design of crystal structures based on the chemical nature of molecular components and functionality is a longstanding and exciting research topic in organic solid state chemistry. Only recently has crystal engineering become an emerging area of inorganic solid state chemistry. With the judicious use of the geochemical and environmental science literature, we continue to develop high yield reactions, control purity, and grow single crystals of new materials that lack inversion symmetry. New materials lacking inversion symmetry (or noncentrosymmetric materials) are the basis of all current and future technologies based on piezoelectricity, pyroelectricity and ferroelectricity. Numerous inventions during the past two decades have been created based on noncentrosymmetric structures. All future advances in this area await the education of a new generation of students capable of the design and synthesis of this special combination of atoms which is required to create noncentrosymmetric materials.Technical Abstract DMRThis project aims to understand how to optimize geometries and the electrostatic potential of metal oxo and oxofluoro-species to create order and avoid disorder in the metal-oxygen and metal-fluoride bonds. The crystal symmetries of the oxyfluorides are determined by the network of contacts the surrounding lattice provides, which are in turn deliberately controlled to create chiral, polar, or chiral-polar three-dimensional solids. Noncentrosymmetric structures are those that lack inversion symmetry. Structures lacking inversion symmetry are a requirement for important current and future technologies that have been created by numerous inventions during the past two decades based on piezoelectricity, pyroelectricity, ferroelectricity and second harmonic generation (SHG). These materials provide a large and new class of solids for studies in basic science associated with the noncentrosymmetric space groups. Stable, robust, high-performance nonlinear optical (NLO) materials with enhanced optical properties at the microscopic and macroscopic level depend on inorganic materials which possess a dipole moment and thus exhibit large optical nonlinearities. These materials are essential for the modification of the amplitude, phase, or frequency of an optical signal. Mixed metal oxide fluorides are a new class of high performance inorganic solid state materials that exhibit polar and chiral (sometimes in combination polar and chiral) structures. Students are trained to carry out semi-combinational syntheses and theoretical modeling studies to guide and advance our program of exploratory synthesis and to achieve high quality single crystals. Crystals are essential for structural studies, characterization and physical measurements of materials which exhibit a nonlinear optical response.