Synthesis, Characterization and Physical Properties of Alkalides and Electrides

碱化物和电子化合物的合成、表征和物理性质

• 批准号: 9402016
• 负责人: James Dye
• 金额: $ 48万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-15 至 1997-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9402016&HistoricalAwards=false
• 关键词: Synthesis; Characterization; Physical; Properties; Alkalides

Abstract 9402016 Dye This research involves the synthesis and characterization of crystalline salts and vapor-deposited thin films that contain alkali metal anions (alkalides) or trapped electrons (electrides) and cations that are complexed by cyclic or bicyclic poly-oxa molecules. Particular emphasis will be given to the study of the optical, magnetic and electrical properties of single crystals using a variety of techniques. Because different electrides have widely different properties, and since their behavior often is dependent on the thermal history of the sample, new complexants will be synthesized to provide a wider assortment of crystalline electrides. Recent theoretical treatments have pointed out the importance of anionic cavities and empty channels in electrides and the extended nature of the unpaired electron wavefunction in molecular electrides. To relate experiment to theory, simple complexants for Li+, such as 9-crown-3, 12-crown-3 and cryptand 1.1.1 will be synthesized and used to prepare electrides for study. The use of alkalides and electrides to prepare nanoscale transition metal and intermetallic particles, both free and in zeolite cages will be studied. %%% This research is concerned with the synthesis and characterization of crystalline salts and vapor-deposited thin films that contain alkali metal anions (alkalides) or trapped electrons (electrides) and cations. Alkalides and electrides are two new, interesting classes of materials. Electrides, in particular, provide the unique opportunity to examine the behavior of electrons that do not "belong" to a particular atom or molecule, but rather, occupy the holes and channels between close-packed large complexed cations. They provide the opportunity to study such phenomena as non-metal to metal transitions in systems that approach a lattice of nearly free electrons, and magnetic interactions and electronic conductivity in 1, 2, and 3 dimensions. Emphasis will be given to the study of the optical, magnetic and ele ctrical properties of single crystals using many characterization methods.

摘要9402016染料本研究涉及含有碱金属阴离子(碱)或俘获电子(电子)和阳离子的结晶盐和气相沉积薄膜的合成和表征，这些离子与环或双环多氧分子络合。将特别强调使用各种技术研究单晶的光学、磁学和电学性质。由于不同的电子材料具有非常不同的性质，而且它们的行为通常取决于样品的热历史，因此将合成新的络合剂以提供更广泛的晶体电子材料。最近的理论处理指出了阴离子空腔和空通道在电子中的重要性，以及未成对电子波函数在分子电子中的扩展性质。为了将实验与理论联系起来，将合成简单的Li+络合剂，如9-冠-3，12-冠-3和加密1.1.1，并用于制备电子进行研究。我们将研究使用碱金属和电子来制备纳米级的过渡金属和金属间化合物颗粒，无论是在自由的还是在沸石笼子中。%本研究涉及含有碱金属阴离子(碱)或俘获电子(电子)和阳离子的结晶盐和气相沉积薄膜的合成和表征。碱金属和电子金属是两类有趣的新材料。特别是，电子器件提供了一个独特的机会来研究电子的行为，这些电子并不“属于”特定的原子或分子，而是占据了紧密堆积的大型络合阳离子之间的空穴和通道。它们提供了机会来研究这样的现象，如接近自由电子晶格的系统中的非金属到金属的转变，以及一维、二维和三维的磁相互作用和电子传导性。重点是用多种表征方法研究单晶的光学、磁学和电学性质。