Stereoelectronic Effects and Reactivity: Lone Pairs, Hydrogen Bonding, and Proton Transfer

立体电子效应和反应性：孤电子对、氢键和质子转移

• 批准号: 9025113
• 负责人: Charles Perrin
• 金额: $ 38.75万
• 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: 1991
• 资助国家: 美国
• 起止时间: 1991-04-01 至 1995-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9025113&HistoricalAwards=false
• 关键词: Stereoelectronic; Effects; Reactivity; Lone; Pairs

With support from the Organic Dynamics Program, Dr. Perrin will utilize nuclear magnetic resonance (NMR) spectroscopy to investigate five separate problems: (i) The stereochemistry of amidinate anions will be studied to complete previous investigations of proton exchange in amides and amidines. (ii) Stereoelectronic control phenomena will be studied by evaluating the effect on reactivity of having one or two lone electron pairs antiperiplanar to a leaving group or incoming nucleophile. (iii) The Method of Isotopic Perturbation of Equilibrium will be utilized as a means to investigate the symmetry of the hydrogen bond. (iv) The extent of solvation of ions in aqueous media will be probed by measuring the effect that these ions have upon bond rotation rates. (v) The phenomenon of large secondary kinetic isotope effects will be studied via examination of bond rotations in amides. %%% Applications of modern nuclear magnetic resonance (NMR) techniques have led to increased understanding of molecular structure and reactivity. Dr. Perrin's research program is designed to take advantage of these new techniques in order to study two of the simplest structural elements in organic molecules, i.e., protons and electron pairs. Five projects will be undertaken in an effort to elucidate the nature of such fundamental phenomena as hydrogen bonding and stuructural/conformational effects on reactivity. The results are likely to be of interest to physical-organic chemists, biochemists, and theoretical chemists.

在有机动力学项目的支持下，佩兰博士将 利用核磁共振（NMR）光谱， 研究五个独立的问题：（一）立体化学的 脒基阴离子将进行研究，以完成以前的 酰胺和脒的质子交换研究。（二） 立体电子控制现象将由 评估具有一个或两个单独的 电子对与离去基团或进入基团反周面 亲核试剂(iii)同位素微扰法 平衡将被用作研究 氢键的对称性。(iv)溶剂化程度 水介质中的离子将通过测量 这些离子对键旋转速率的影响。(v)的 大的次级动力学同位素效应的现象将是 研究通过检查键旋转酰胺。 %%% 现代核磁共振（NMR）的应用 技术已经导致了对分子生物学的更多理解， 结构和反应性。佩林博士的研究项目是 旨在利用这些新技术， 研究两种最简单的有机结构元素， 分子，即，质子和电子对。五个项目将 努力阐明这种现象的性质 氢键等基本现象， 结构/构象对反应性的影响。结果 可能会引起物理有机化学家的兴趣， 生物化学家和理论化学家。