Solvent-structuring at the interface between crystals and mixed organic-aqueous solvents

非技术摘要：溶液结晶是广泛的工业，实验室和生理过程的基础。近年来，有机液体和混合有机-含水液体作为用于制备结晶材料和通过结晶分离（或纯化）的替代溶剂，特别是用于高价值材料如药物和精细化学品的替代溶剂，引起了越来越多的关注。与从水溶剂中结晶相反，对从有机溶剂中晶体生长的基本过程的理解水平受到严重限制。缺乏对相关基本机制和途径的深入了解已成为优化和控制有机和混合有机-水介质中结晶的合理方法的主要障碍。该项目的目的是提供理解的分子过程，包括结晶从混合溶剂中的热力学和动力学的潜在solventstructure.Technical摘要：的后果，有机和混合溶剂在结晶中发挥的作用是在这个项目中解决的悬而未决的问题。在晶体-溶液界面的溶剂结构，其特征在于先进的原子力显微镜成像和相关的结晶热力学的影响。溶剂的化学性质如何影响结晶机制是通过确定溶质分子在通往晶体生长位点的途中所采取的步骤来阐明的。的性质的激活障碍分子纳入晶体阐明建立是否溶剂结构化和与溶剂分子的相互作用的主要机制，这种障碍的存在。确定分子机制中的步骤及其各自的控制参数提供了优化和控制从有机溶剂和混合溶剂中结晶并抑制缺陷诱导不稳定性的工具。比较几个卟啉溶剂对的数据阐明了溶剂中的化学部分的作用和它们在溶剂结构的形成中形成氢键和货车德瓦尔斯键的能力。解开交错的化学和物理过程，包括结晶和确定相关的控制参数代表了一个新的范式，在合理设计的有机晶体。

Non-technical Abstract:Solution crystallization underlies a broad range of industrial, laboratory, and physiological processes. In recent years, organic and mixed organic-aqueous liquids have garnered increased interest as an alternative solvent for the preparation of crystalline materials and separation (or purification) by crystallization, in particular for high-value materials such as pharmaceuticals and fine chemicals. In contrast to crystallization from aqueous solvents, the level of understanding of the fundamental processes of crystal growth from organic solvents is severely limited. The lack of insight into the relevant fundamental mechanisms and pathways has emerged as the main obstacle to a rational approach to the optimization and control of crystallization in organic and mixed organic-aqueous media. The objective of this project is to provide understanding of the molecular processes comprising crystallization from mixed solvents focusing on the thermodynamic and kinetic consequences of potential solvent structuring.Technical Abstract:The roles that organic and mixed solvents play in crystallization are the open question addressed in this project. The solvent structures at the crystal-solution interface are characterized by advanced atomic force microscopy imaging and correlated with their effects on the thermodynamics of crystallization. How the chemical properties of the solvent affect the crystallization mechanism is elucidated by determining the steps that a solute molecule takes en route to a crystal growth site. The nature of the activation barrier for incorporation of molecules into the crystal is elucidated to establish whether solvent structuring and interactions with solvent molecules are the primary mechanisms underlying the existence of this barrier. Determining the steps in the molecular mechanism and their respective governing parameters provides tools to optimize and control crystallization from organic and mixed solvents and suppress defect-inducing instabilities. Comparing data for several porphyrin-solvent pairs elucidates the roles of the chemical moieties in the solvents and their abilities to form hydrogen and van der Waals bonds in the formation of solvent structures. Untangling the interlaced chemical and physical processes comprising crystallization and identifying the relevant governing parameters represents a new paradigm in the rational design of organic crystals.