Multinuclear Solid-State Nuclear Magnetic Resonance and Density Functional Theory Characterization of Interaction Tensors in Taurine

A variety of experimental solid-state nuclear magnetic resonance (NMR) techniques has been used to characterize each of the elements in 2-aminoethane sulfonic acid (taurine). A combination of N-15 cross-polarization magic angle spinning (CPMAS), N-14 ultrawideline, and N-14 overtone experiments enabled a determination of the relative orientation of the nitrogen electric field gradient and chemical shift tensors. O-17 spectra recorded from an isotopically enriched taurine sample at multiple magnetic fields allowed the three nonequivalent oxygen sites to be distinguished, and NMR parameters calculated from a neutron diffraction structure using density functional theory allowed the assignment of the O-17 parameters to the correct crystallographic sites. This is the first time that a complete set of O-17 NMR tensors are reported for a sulfonate group. In combination with H-1 and C-13 MAS spectra, as well as a previously reported S-33 NMR study, this provides a very broad set of NMR data for this relatively simple organic molecule, making it a potentially useful structure on which to test DFT calculation methods (particularly for the quadrupolar nuclei N-14, O-17, and S-33) or NMR crystallography approaches.