Determination of Acidity Functions of Liquid Acids by Carbon-13 Nuclear Magnetic Resonance and Development of Theoretically Justified Calibration of Solid Acidity

用碳 13 核磁共振测定液体酸的酸度函数以及固体酸度的理论合理校准的发展

• 批准号: 9121454
• 负责人: Dan Farcasiu
• 金额: $ 23.78万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-06-01 至 1996-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9121454&HistoricalAwards=false
• 关键词: Determination; Acidity; Functions; Liquid; Acids

The objective of this project is the development of a new method based on carbon-13 nuclear magnetic resonance chemical shifts for determining thermodynamic acidity functions for liquid and solid acids. Medium effects are eliminated by using the difference in chemical shift between two carbon atoms in the same molecule as the measurement parameter. The new method is applicable to systems lacking the transparency to visible and ultraviolet light required for use of traditional Hammett indicators, and is extendable to solids. To relate solid acidity to solution acidity, the protonation equilibrium of indicator bases in solution is studied at the stoichiometric acid-to-base ratio and the same indicator bases are then studied on solid acids at equimolar ratios of base to acid sites. Finally, the effects of solvents on acid strengths is examined. Although the concept of acidity is often used to interpret the effects of solid catalysts, there is, in fact, no sound technique to measure or quantify this property for solids. This project addresses this problem directly; success would provide a more rational framework for understanding of many catalytic systems, and also of corrosion, composite stability, and chromophoric displays.

该项目的目标是开发一种新的 基于碳-13核磁共振化学的方法 确定热力学酸度函数的位移 液体和固体酸。 介质效应通过以下方式消除： 利用两个碳原子之间化学位移的差异 原子在同一分子作为测量参数。 的 新方法适用于缺乏透明度的系统 使用所需的可见光和紫外光 传统的Hammett指标，并可扩展到固体。 为了将固体酸性与溶液酸性联系起来， 研究了指示剂碱在溶液中的平衡， 化学计量酸碱比和相同的指示碱 然后在等摩尔比的碱与 酸性位点 最后，讨论了溶剂对酸的影响。 实力被检验。 虽然酸度的概念经常被用来解释 在固体催化剂的作用下， 测量或量化固体这种性质的技术。 该项目直接解决了这个问题;成功将 提供了一个更合理的框架来理解许多 催化系统，以及腐蚀，复合稳定性， 和发色显示器。