Solid-State Reactions of Molecular Crystals

本项目将探索发生在聚集体或分子晶体内部或表面的自然过程。为了理解这些过程，更重要的是，学习如何控制它们，最有成效的方法是研究结晶固体中的反应。这类反应对合成化学家也有相当大的前景，因为它们中的许多是高度选择性的，产生的产物纯度非常高，这通常是溶液法无法获得的。提出的研究将确定和开发有效的新的，前所未有的反应，发生在缺乏溶剂。除了在研究中获得的新材料之外，在这个环保的“绿色化学”领域中进行的反应，比它们的溶液对应的反应需要更少的能源，产生更少的废物。固态化学和材料化学（对称、晶体学和反应）的主要教学内容是通过一系列互动式ppt课程进行分发的，其中一个课程已经在PI的网站上发布。为了建立坚实的教育基础和激励崭露头角的科学家，该方法将与当地高中教师合作，在中学版本中实施，涵盖对称和固态化学的早期概念。美国科学家要想在21世纪在化学和材料科学领域保持领导地位，当代和未来几代人接受最好的技术指导至关重要。参与者将接受材料物理和合成方面以及环境无害化学方面的重点培训，并将有机会在培训期间通过美国国家科学基金会国际和马克斯普朗克研究学院的项目在国外工作。非技术解释固态反应的研究为发现经过立体定向分子间转化的新型材料提供了难得的机会。在这些不寻常的过程中，结晶金属盐和有机材料用热、紫外线或伽马射线处理，在几种可能的化学上不同的异构体中只产生一种。除了为学生提供最先进的培训外，使用x射线晶体学，完整的产品表征，同位素标记，激光光化学和x射线地形学的研究将对固体分子间反应的几何，物理和化学机制有详细的了解。总的来说，作为对“绿色”化学的贡献，提议的工作有望产生新的，高效的无溶剂工艺，并为理解这些工艺如何发生提供机制基础。此外，在PI的网站上还有一个基于ppt的空间群对称互动课程，这是固态化学教学的一个主要领域。新的学习方法将在中学版本中实施，包括对称和固态化学的基本概念，与当地高中教师合作。美国科学家要想在21世纪在化学和材料科学领域保持领导地位，当代和未来几代人接受最好的技术指导至关重要。

TECHNICAL EXPLANATION This project will explore natural processes that take place within, or on the surface of, aggregates or molecular crystals. In order to understand these processes, and more importantly, to learn how to control them, the most fruitful approach is to study reactions in crystalline solids. Such reactions also hold considerable promise for the synthetic chemist, since many of them are highly selective, giving products of very high purity that are often not available from solution processes. The proposed research will identify and exploit efficient new, unprecedented reactions that occur in the absence of solvent. Beyond the new materials obtained in the research, reactions in this environmentally-friendly area of "Green Chemistry" promise to require less energy, and produce less waste, than their solution counterparts. Primary instruction in solid-state and materials chemistry (symmetry, crystallography and reactions) is being distributed through sets of interactive PowerPoint courses, one of which is already available on the PI's website. With a view to establishing a firm educational base and stimulation for budding scientists, the approach will be implemented in a secondary school version, covering symmetry and early concepts in solid-state chemistry, in collaboration with local high school teachers. For US scientists to sustain a leadership role in chemistry and materials science in the 21st century, it is critical that the current and coming generations receive the best possible technical instruction. Participants will receive key training in the physical and synthetic aspects of materials and environmentally-benign chemistry, and will have the opportunity to work abroad during their training period through NSF International and Max Planck Research School programs.NON-TECHNICAL EXPLANATIONStudies of solid-state reactions offer exceptional opportunities for the discovery of new classes of materials that undergo stereospecific intermolecular transformations. In these unusual processes, where crystalline metal salts and organic materials are treated with heat, UV or gamma-rays, only one out of several possible chemically distinct isomers is produced. In addition to providing state-of-the-art training for students, studies using X-ray crystallography, full product characterization, isotopic labeling, laser photochemistry and X-ray topography will yield a detailed understanding of the geometrical, physical and chemical mechanisms of intermolecular reactions in solids. Overall, the proposed work, as a contribution to "Green" chemistry, promises to yield new, efficient solventless processes, as well as providing a mechanistic basis for understanding how those processes occur. In addition, an interactive PowerPoint-based course in Space Group Symmetry, a primary area of instruction in solid-state chemistry, is available from the PI's website. The novel learning approaches will be implemented in a secondary school version, covering symmetry and beginning concepts in solid-state chemistry, in collaboration with local high school teachers. For U.S. scientists to sustain a leadership role in chemistry and materials science in the 21st century, it is critical that the current and coming generations receive the best possible technical instruction.