Use of RDCs in rigid organic compounds and some practical considerations concerning alignment media

作者：Thiele Christina M^*

来源：Concepts in Magnetic Resonance: Part A , 2007, 30A(2): 65-80.

DOI：10.1002/cmr.a.20075

• partial alignment
• residual dipolar couplings
• variable angle sample spinning
• polyglutamates
• diastereotopic groups
• relative configuration

A molecule that is introduced into a liquid crystal or alignment medium forfeits its isotropic tumbling motion. The resulting partial alignment leads to observable anisotropic interactions, dipolar couplings being one. To control the degree of alignment that the molecule experiences is essential to retain the quality of high-resolution solution-state spectra. An overview of alignment media is given. The problems associated with very large residual dipolar couplings (RDCs) are pointed out, and means to reduce residual dipolar couplings (RDCs) for strychnine in substituted polyglutamate liquid crystals are described. The use of RDCs for the assignment of diastereotopic protons and for the determination of the relative configuration in rigid compounds is then described in detail, also pointing out some pitfalls.

• 出版日期2007-3