Chiral derivatizing agents, macrocycles, metal complexes, and liquid crystals for enantiomer differentiation in NMR spectroscopy.

摘要: Enantiomerically pure chiral auxiliary agents are often used in NMR spectroscopy to facilitate the differentiation of enantiomers. Chiral derivatizing covalently bound substrate and differences chemical shifts resulting diastereomeric complexes analysis. Macrocycles such as cyclodextrins, crown ethers, calix[4]resorcinarenes solvating that associate with through non-covalent interactions. Enantiomeric occurs spectrum because nature associated and/or association constants between two enantiomers reagent. Metal Lewis acids bind suitable base donor compounds. Exchange can be slow or fast depending on particular metal ion, mimicking behavior a agent, respectively. liquid crystals undergo partial alignment an applied magnetic field dissolved crystal well. If is different, enantiomeric potentially observed by shifts, dipolar coupling constants, different magnitudes splitting quadrupolar nuclei deuterium. The reagents described herein determine composition sometimes assign absolute configuration. Significant discoveries well recent findings each these types systems described.