MEDIUM EFFECTS ON CONFORMATIONAL ISOMERISM

对构象异构的中等影响

• 批准号: 3277621
• 负责人: NANCY S TRUE
• 金额: $ 6.81万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 1982
• 资助国家: 美国
• 起止时间: 1982-02-01 至 1988-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3277621
• 关键词: amides; chemical group; conformation; cyclic amine; diazo compound; ketones; microwave spectrometry; nuclear magnetic resonance spectroscopy; phase change; thermodynamics

We propose complementary gas and liquid phase NMR studies of conformational equilibria and conformational dynamics in both polar and nonpolar cyclic and acyclic molecules which model biologically important functional groups. This research is aimed at elucidating the direction and extent of solvent perturbations on torsional potential functions and conformational processes. Below we will demonstrate that for many model compounds such as amides, cyclic amines, and diazoketones it is possible with techniques we have recently developed to measure the temperature dependence of conformer populations and interconversion rates in the gas phase with NMR spectroscopy to yield a complete set of thermodynamic and kinetic parameters characterizing each conformational process. Comparison with corresponding liquid phase results will allow elucidation of the magnitude of intrinsic and environmental contributions to each internal rotation potential function. For each class of compounds, a series of molecules with systematic variations in substituent size and polarity will be investigated. Intramolecular effects on torsional potentials and conformational dynamics will be probed by comparison of gas phase thermo-dynamic and kinetic data within each series. Intermolecular effects will be probed by comparison of gas and solution data for each molecule within a series. Complementary microwave spectral data will provide additional structural and dynamic information. These studies will yield widely applicable parameters for solvent contribution to torsional potentials of biologically important functional groups and their associated conformational equilibria and dynamics. This information is essential for progress in elucidating molecular potentials, dynamics and mechanisms of conformational processes in biomolecules.

我们提出了互补的气相和液相核磁共振研究的构象 平衡和构象动力学的极性和非极性循环 和模拟生物学重要功能的非环状分子 组 本研究的目的在于阐明 溶剂对扭转势函数和构象的扰动 流程. 下面我们将证明，对于许多模型化合物， 酰胺、环胺和重氮酮，使用我们 最近开发了测量构象异构体的温度依赖性 在气相中的粒子数和相互转化率与NMR 光谱，以产生一整套热力学和动力学 表征每个构象过程的参数。 相比 相应的液相结果将允许阐明的幅度 内在的和环境的影响 势函数 对于每一类化合物，一系列分子与系统 将研究取代基大小和极性的变化。 分子内效应对扭转势和构象动力学的影响 将通过气相热力学和动力学数据的比较来探讨 在每个系列中。 分子间的影响将通过比较 气体和溶液数据的每个分子在一个系列。 互补 微波光谱数据将提供更多的结构和动态 信息. 这些研究将产生广泛适用的参数， 溶剂对生物学上重要扭转电位的贡献 官能团及其相关的构象平衡， 动力学 这一信息对于阐明 构象过程的分子势、动力学和机制 在生物分子中。