CONFORMATIONAL STUDY BY DYNAMIC NMR SPECTROMETRY

建议的研究分为四个部分，每个部分 涉及到核磁共振波谱在下列问题中的应用 构象分析或结构测定。在第一个 第一部分，17O核磁共振在动态核磁共振中的应用 研究了(N-叔丁基硝胺)，并将使用17O核磁共振 几种双-三甲基硅酰胺(酰胺或 酰亚胺结构)。~(33)S核磁共振的分辨能力 将确定单键硫磺和双键硫磺之间的关系。 在某些情况下，将使用接近临界温度的溶剂 以减小线宽。许多生物化合物 重要性包含氧或硫，光谱将提供 关于~(17)O在~(33)S核磁共振研究中的作用 这些化合物中。 在第二部分中，几种含硒化合物的旋转障碍 化合物将被测量，以表明硒可以是一种 有效的捐赠者。 第三部分，酰基的受阻旋转和氮转化 氮杂环丙烷将通过动态核磁共振波谱进行研究，以获得 有关酰胺中共轭重要性的信息 这些化合物的键，并证明金字塔 酰胺中的氮仍然可以有效地与羰基结合。 一群人。 第四部分介绍了几个非取代化合物的动态核磁共振研究 环十二烷。取代基的相对择优 将确定环中的各种可能位置，并 将提供对以下文献价值的实验检验 通过分子力学计算得到CH3。

The proposed research is divided into four parts, each of which involves the application of NMR spectroscopy to problems in conformational analysis or structural determination. In the first part, the usefulness of 17 O NMR in dynamic NMR will be examined (N-tert butyl nitramine), and 17 O NMR will be used to assign structures to several bis-trimethylsilyl amides (amide or imidate structure). The ability of 33S NMR to distinguish between singly and doubly bonded sulfur will be determined. Solvents near the critical temperature will be used in some cases to reduce the line widths. Many compounds of biological importance contain oxygen or sulfur, and the spectra will provide information about the potential of 17 O on 33 S NMR for studies of these compounds. In part II, barriers to rotation in several selenium-containing compounds will be measured to show that selenium can be an effective - donor. In part III, hindered rotation and nitrogen inversion in acyl aziridines will be studied by dynamic NMR spectroscopy to obtain information about the importance of conjugation in the amide bond of these compounds, and to demonstrate that pyramidel nitrogen in an amide can still bond effectively with the carbonyl group. Part IV describes a dynamic NMR study of several nonsubstituted cyclodecanes. The relative preferences of the substituents for the various possible positions in the ring will be determined and will provide an experimental check on the literature values for CH 3 obtained by molecular mechanics calculations.