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We report a comprehensive variable-temperature solid-state 17 O NMR study of three 17 O-labeled crystalline sulfonic acids: 2-aminoethane-1-sulfonic acid (taurine, T), 3-aminopropane-1-sulfonic acid (homotaurine, HT), and 4-aminobutane-1-sulfonic acid (ABSA − groups in these compounds undergo a 3-fold rotational jump mechanism but also extracted the corresponding jump rates (10 2 −10 5 s −1 ) and the associated activation energies (E a ) for this process (E a =4 8± 7, 42 ± 3, and 45 ± 1 kJ mol −1 for T, HT, and ABSA, respectively). This is the first time that SO 3 − rotational dynamics have been directly probed by solid-state 17 O NMR. Using the experimental activation energies for SO 3 − rotation, we were able to evaluate quantitatively the total hydrogen bond energy that each SO 3 − group is involved in within the crystal lattice. The activation energies also correlate with calculated rotational energy barriers. This work provides a clear illustration of the utility of solid-state 17 O NMR in quantifying dynamic processes occurring in organic solids. Similar studies applied to selectively 17 O-labeled biomolecules would appear to be very feasible.

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