Solid-State Reactions of Molecular Crystals

分子晶体的固态反应

• 批准号: 9629994
• 负责人: Bruce Foxman
• 金额: $ 27.4万
• 依托单位: Brandeis University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-10-01 至 2000-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9629994&HistoricalAwards=false
• 关键词: Solid; State; Reactions; Molecular; Crystals

Abstract 9629994 Foxman This research is focussed on the investigation of a broad range of solid-state reactants. First, metal salts of unsaturated carboxylic acids will be exposed to ionizing radiation. By using criteria established in previous studies, it will be possible to discover new types of oligomerization and polymerization reactions. Crystallographic studies of reactants will aid in the understanding of the geometrical and chemical mechanism associated with each process. Parallel studies of the structures and thermal solid-state reactivity of amine:carboxylic acid cocrystals will enhance understanding of chemospecific Michael addition reactions. A proposed X-ray structural and topographic investigation of radiation-induced phase transitions in copper carboxylate complexes will elucidate the role of strain and dislocations as a twinned triclinic phase transforms to a monoclinic single crystal. Second, a series of molecular solids ranging from cinnamic acids to acrylamide to metal acrylates will be irradiated in the low-energy "tail" of the absorption band of the corresponding chromophore. Based upon preliminary experiments, this research promises to produce single crystals of dimers, oligomers and polymers. Similarly, solid-state condensation reactions in A:B cocrystals, where A = an aminopyridine or hydroxypyridine and B = a substituted benzoyl chloride, will provide valuable information on thermal reactions where an evolved gas (HCl) is trapped, for example, by a pyridine acceptor. Such a process is expected to lead to a solid-state reaction with a negligible change in unit-cell volume. Both of these processes will provide the necessary guidelines for the production of highly ordered crystalline polymers. Third, experiments, using synchrotron X-rays, in which solid metal salts are irradiated at specific wavelengths near the absorption edge for the metal, promise to provide definitive information about the detailed role of the metal in the radiat ion-induced oligomerization of metal propynoates. The phenomenon of isomorphous substitution, where metals can be substituted without changing the structure of the material, will be used in propynoate salts to tailor their sensitivity to ionizing radiation, allowing the radiation sensitivity to be varied over a wide range. Metal propynoates are thus excellent prospects for new applications involving radiation dosimetry; experiments will be conducted to establish the useful dosimetric ranges of these materials. %%% Solid-state reactions offer exceptional opportunities for chemospecific and stereospecific synthesis, the production of single crystals of oligomers and polymers, and the discovery of novel applications for new materials. In optimal cases, irradiation or thermolysis of crystals can lead to unusual stereospecific intermolecular reactions that cannot be accomplished in solution. The challenge lies in discovering new classes of materials capable of solid-state reactivity, and in determining the principles which govern their behavior. A proper set of objectives for a research program in this area must involve (a) the design, discovery and characterization of new solid-state reactions, (b) the study and exploitation of new phenomena discovered in the course of the research, (c) the design of new experiments which will help to identify geometrical criteria and/or pathways for the reactivity of solids, and the chemical and physical factors responsible for that reactivity, and (d) a search for applications for either the reactants or the products associated with a solid-state reaction and/or phase transition. In the past, this research has concentrated on the discovery of new solid-state reactions to increase both the quality of the materials and the understanding of how basic processes occur. Critical experiments are now designed to investigate a broad range of solid-state reactants, and to firmly establish new applications for the new materials.

摘要 9629994 福克斯曼 这项研究的重点是广泛的固态反应物的调查。首先，不饱和羧酸的金属盐将暴露于电离辐射。通过使用在以前的研究中建立的标准，将有可能发现新类型的低聚和聚合反应。反应物的晶体学研究将有助于理解与每个过程相关的几何和化学机制。 对胺：羧酸共晶的结构和热固态反应性的平行研究将增强对化学特异性迈克尔加成反应的理解。一个建议的X射线结构和地形调查辐射诱导的相变在铜羧酸盐络合物将阐明应变和位错的作用作为一个孪生的三斜相转变为单斜单晶。第二，从肉桂酸到丙烯酰胺到金属丙烯酸酯的一系列分子固体将在相应发色团的吸收带的低能“尾部”被照射。 基于初步的实验，本研究有望产生二聚体，低聚体和聚合物的单晶。类似地，在A：B共晶体中的固态缩合反应，其中A =氨基吡啶或羟基吡啶，B =取代的苯甲酰氯，将提供关于热反应的有价值的信息，其中放出的气体（HCl）被捕获，例如，被吡啶受体捕获。这样的过程预计将导致固态反应，单位电池体积的变化可以忽略不计。这两种方法都将为生产高度有序的结晶聚合物提供必要的指导。 第三，使用同步加速器X射线的实验，其中固体金属盐在金属的吸收边附近的特定波长下照射，有望提供关于金属在金属丙炔酸盐的辐射离子诱导的低聚中的详细作用的明确信息。同晶取代的现象，其中金属可以取代而不改变材料的结构，将用于丙炔酸盐中，以调整其对电离辐射的敏感性，允许辐射敏感性在很宽的范围内变化。因此，金属丙炔酸盐是涉及辐射剂量测定的新应用的极好前景;将进行实验以建立这些材料的有用剂量测定范围。 固态反应为化学特异性和立体特异性合成、低聚物和聚合物单晶的生产以及新材料新应用的发现提供了绝佳的机会。在最佳情况下，晶体的辐照或热处理可导致不寻常的立体特异性分子间反应，这在溶液中无法完成。挑战在于发现能够固态反应的新材料类别，并确定控制其行为的原则。这一领域的研究计划的一套适当的目标必须包括：（a）新的固态反应的设计、发现和表征，（B）研究和利用研究过程中发现的新现象，（c）设计有助于确定固体反应性的几何标准和/或途径的新实验，以及负责该反应性的化学和物理因素，以及（d）寻找与固态反应和/或相变相关的反应物或产物的应用。在过去，这项研究集中在发现新的固态反应，以提高材料的质量和对基本过程如何发生的理解。临界实验现在被设计成研究广泛的固态反应物，并为新材料建立新的应用。