NMR enantiodifferentiation studies are greatly improved by the simultaneous determination of (1)H and (13)C chemical shift differences through the analysis of highly resolved cross-peaks in spectral aliased pure shift (SAPS) HSQC spectra.

A frequency-selective 1D (1) H nuclear magnetic resonance (NMR) experiment for the fast and sensitive determination of chemical-shift differences between overlapped resonances is proposed. The resulting fully homodecoupled (1) H NMR resonances appear as resolved 1D singlets without their typical J(HH) coupling constant multiplet structures. The high signal dispersion that is achieved is then exploited in enantiodiscrimination studies by using chiral solvating agents.

The utility of (13)C NMR spectroscopy for the differentiation of enantiomers using chiral solvating agents (CSA) is stated. Three examples involving the enantiodifferentiation of a drug, a metabolite and a reactant in aqueous and organic solutions have been chosen to show it. The intrinsic high dispersion of (13)C nucleus, as well as the singlet nature of the signals in standard experiments makes (13)C NMR experiments a powerful alternative or complement to (1)H NMR experiments; specially, when studying pure compounds with complex proton spectra or mixtures of compounds, as in chiral metabonomics, where severe overlapping exists in proton spectrum. To evaluate and compare the quality of the enantioresolution of a NMR signal we introduce the enantiodifferentiation quotient, E, that considers the complexity of (1)H multiplets (and in general the width) of the original signal. It has been observed that the error in the measurement of the enantiomeric molar ratio can be related to the E value. The sensitivity and experimental time of a wide range of chiral analyte concentrations were also assessed.

The synthesis, structural characterization and the successful application of a carbon centered radical derived from 1,3-bisdiphenylene-2-phenylallyl (BDPA), its benzyl alcohol derivative (BA-BDPA), as a polarizing agent for Dynamic Nuclear Polarization (DNP) are described. The reported BA-BDPA radical meets all the requirements to become a promising candidate for its use in in vivo DNP-NMR experiments: it is soluble in neat [1-(13)C]pyruvic acid, insoluble in the dissolution transfer solvent and is effective as a polarizing agent in fast dissolution DNP-NMR applications, without the need for using glassing agents. Moreover, it enables a simple but effective in-line radical filtration to obtain hyperpolarized solutions of [1-(13)C]pyruvic acid free of radicals that offers a better polarization performance.

For the first time, it is shown that VCD spectroscopy can be used to determine the % ee in chiral solid samples.