Hydrogen Bonds, Conformations, Reactivity, and Solvation

氢键、构象、反应性和溶剂化

• 批准号: 0742801
• 负责人: Charles Perrin
• 金额: $ 51.6万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2012-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0742801&HistoricalAwards=false
• 关键词: Hydrogen; Bonds; Conformations; Reactivity; Solvation

Since this is a performance based proposal, the proposed research of the Perrin Laboratory perforce covers a wide range of topics, including symmetry of hydrogen bonds (H-bonds), conformational analysis, anomeric effects, steric hindrance to ionic solvation, isotope effects (IEs) on acidity, NMR coupling constants, and the chemical reactivity of para-benzynes and malonic anhydrides. Techniques include multinuclear NMR, NMR titration, calorimetry, and computation. A frequent theme of these projects is solvation, which (1) affects H-bonds by breaking the symmetry of the local environment, (2) becomes less effective for sterically hindered ionic groups, (3) affects IEs by H-bonding to lone pairs, and (4) reduces the reactivity of nucleophiles toward para-benzynes. Examples of specific projects include the study of anomeric effects on stabilizations of anions that arise from properly positioned electron pairs in certain small organic molecules, NMR titration studies on deuterium IEs on acidity and their conformational dependence, and calculations of the conformational dependence of NMR coupling constants in ethers, amines, thioethers and their derivatives.The broader impact of these studies for advancing discovery remains quite long-range, since the studies are not aimed at practical application but at developing a thorough understanding of some fundamental chemistry, to guide further research in physical organic chemistry. The broader educational impact of these studies is far-reaching. Students learn to ask and answer questions, to solve problems, and to think critically. In recent years many of them have been inspired to enter academia. In addition, Prof. Perrin was elected chair of the 2006 Gordon Conference on Isotopes, where he made special efforts to encourage participation by graduate students and postdoctoral researchers, and provided financial support to them.

由于这是一个基于性能的提案，因此Perrin实验室的拟议研究必然涵盖广泛的主题，包括氢键（H-键）的对称性，构象分析，端基异构效应，离子溶剂化的空间位阻，酸度的同位素效应（IE），NMR耦合常数以及对苯炔和丙二酸酐的化学反应性。 技术包括多核NMR，NMR滴定，量热法和计算。 这些项目的一个常见主题是溶剂化，它（1）通过破坏局部环境的对称性来影响氢键，（2）对空间位阻离子基团变得不那么有效，（3）通过氢键与孤对电子作用来影响IE，以及（4）降低亲核试剂对对位苯炔的反应性。具体项目的例子包括研究端基异构体对某些小有机分子中适当定位的电子对产生的阴离子稳定性的影响，氘离子交换物对酸度及其构象依赖性的NMR滴定研究，以及计算醚，胺，硫醚及其衍生物。这些研究对推进发现的更广泛影响仍然相当长远，因为这些研究不是为了实际应用，而是为了加深对一些基础化学的理解，以指导物理有机化学的进一步研究。这些研究的广泛教育影响是深远的。 学生学习提问和回答问题，解决问题，并批判性地思考。 近年来，他们中的许多人受到启发进入学术界。此外，Perrin教授还当选为2006年戈登同位素会议主席，他特别努力鼓励研究生和博士后研究人员参与，并为他们提供财政支持。