Real time band selective F1-decoupled proton NMR for the demixing of overlay spectra of chiral molecules.
The small chemical shift dispersion and complex multiplicity pattern in proton NMR limit quantifications, for instance the determination of enantiomeric excess (ee) for an enantiomeric mixture. Herein, we present a simple proton-proton correlation experiment with band selective homonuclear (BASH) decoupling in both F1and F2dimensions, for the removal of scalar and residual dipolar couplings to provide collapsed singlet for each chemical site. The method has been demonstrated to separate the severely overlapped spectra of enantiomers using both chiral isotropic and anisotropic phases as well as a small biomolecule, particularly for the diastereotopic protons and also for the determination of ee. Copyright © 2016 John Wiley & Sons, Ltd.
Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany.
Nilamoni
N
Nath
Centre of Biomedical Research, SGPGIMS Campus, Lucknow, U. P., India.
Ajay
A
Verma
Centre of Biomedical Research, SGPGIMS Campus, Lucknow, U. P., India.
Bikash
B
Baishya
Centre of Biomedical Research, SGPGIMS Campus, Lucknow, U. P., India.
Chunni Lal
CL
Khetrapal
Chiral discrimination; Chiral liquid crystal; Lanthanide shift reagent; Pure shift NMR