CONFORMATIONAL STUDY BY DYNAMIC NMR SPECTROMETRY

本研究共分为四个部分， 涉及应用核磁共振光谱学的问题， 构象分析或结构测定。 上 第一部分，17 ONMR在动态NMR中的应用， 检查（N-叔丁基硝胺），17 O NMR将用于 将结构分配给几种双三甲基甲硅烷基酰胺（酰胺或 酰亚胺化结构）。 33 S NMR区分 将确定单键和双键硫之间的关系。 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 重要的是含有氧或硫，光谱将提供 关于17 O在33 S NMR上的潜力的信息，用于研究 这些化合物。 在第二部分中，在几个含硒 化合物将被测量，以表明硒可以是一种 有效供者。 在第三部分中，研究了酰基的受阻旋转和氮转化， 氮杂环丙烷将通过动态NMR光谱研究，以获得 关于酰胺中共轭重要性的信息 这些化合物的键，并证明， 酰胺中的氮仍然可以有效地与羰基键合， 组 第四部分介绍了几个非取代的动态NMR研究 环癸烷。 取代基的相对优选性 将确定环中的各种可能位置， 将提供一个实验检查的文献价值， 通过分子力学计算得到的CH 3。

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.