Journal of Physical Chemistry A, Vol.104, No.15, 3326-3331, 2000
Extracting residual NMR coupling constants from electrically aligned liquids
Molecular alignment by an electric field is used to reintroduce quadrupolar couplings into the nuclear magnetic resonance spectrum of polar liquids. By interleaving a pulsed electric field with rf pulse sequences in a controlled way, spectral simplification is introduced by correlating isotropic chemical shifts with residual anisotropic couplings in a two-dimensional fashion. The success of these experiments is facilitated by combining rapid pi rf pulsing with multiple quantum filtration to minimize molecular motion effects on the measured signal. An analysis of the observed coupling constants and their relation to molecular Structure are provided.