New methods for the measurement and evaluation of anisotropic NMR parameters for the configurational assignment of molecular structures

测量和评估分子结构构型分配的各向异性 NMR 参数的新方法

• 批准号: 528400063
• 负责人: Professor Dr. Christian Griesinger
• 金额: --
• 依托单位: Arbeitsgruppe Organische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/528400063?language=en
• 关键词: New; methods; measurement; evaluation; anisotropic

The application of anisotropic NMR parameters in the structure determination of dissolved organic compounds is of increasing importance. This is especially true for residual dipolar couplings (RDCs), but also for residual quadrupolar couplings (RQCs). Recently, residual chemical shift anisotropy (RCSA) has been added, mainly by the Griesinger group. In addition to 13C-RCSA, methods have been developed that also allow 1H-RCSA to be measured, which is particularly attractive for reasons of measurement sensitivity. The measurement of anisotropic parameters requires a restriction of the isotropic movement of the molecules, which up to now has essentially been achieved by lyotropic liquid crystalline phases (LLC) or by mechanically deformed polymer gels. Electric fields are now to serve as a completely new variant for the generation of this "weak alignment", which bring this about either indirectly through alignment of the polymer chains, or directly through interaction of the E-field with the analytes. In connection with this measurement method project, which is being worked on by both groups (CG and MR) new approaches to structurally diverse, helically chiral, polyacetylenes and polyisonitriles are to be developed. These will then serve both as a basis for fundamental investigations into the problem of enantiomer-differentiating alignment and for solving challenging problems of relative configurations of natural products. In collaboration, attempts will be made to determine absolute configurations. For this purpose, NMR data will be collected in the chiral media and then processed using novel software solutions.

各向异性核磁共振参数在溶解有机物结构测定中的应用日益重要。这对于残余偶极耦合（RDC）尤其如此，但对于残余四极耦合（RQC）也是如此。最近，主要由Griesinger小组增加了残余化学位移各向异性（RCSA）。除了13 C-RCSA之外，还开发了允许测量1H-RCSA的方法，由于测量灵敏度的原因，这是特别有吸引力的。各向异性参数的测量需要限制分子的各向同性运动，到目前为止，这基本上是通过溶致液晶相（LLC）或通过机械变形的聚合物凝胶来实现的。电场现在作为一种全新的变体，用于产生这种“弱排列”，这通过聚合物链的排列间接地或直接通过电场与分析物的相互作用来实现。在这个测量方法的项目，这是由两个小组（CG和MR）的新方法，以结构多样，螺旋手性，聚乙炔和聚异腈正在开发。然后，这些将作为基础的对映体差异对齐的问题，并解决具有挑战性的问题，相对配置的天然产物的基本调查。在合作中，将尝试确定绝对配置。为此，将在手性介质中收集NMR数据，然后使用新的软件解决方案进行处理。