Variable-temperature 2 H wideline (static) spectra and T1 relaxation data were acquired at 76.71 MHz for the FSPAacetone-d6 sample and 61.42 MHz for the FSPA-ethanol-d2 sample. FSPA-ethanol-d2 spectra used 0.2-0.5 s recycle delay and a 40 μs echo delay. FSPA-acetone-d6 spectra used a 1 s recycle delay and 60 μs echo delay. T1 relaxation measurements were performed using a saturation recovery sequence for both samples, and single exponential decays were fitted to the integral of the complete bandshape / sideband pattern as a function of recovery time. Excellent single-exponential fits were obtained at all temperatures on both samples. FSPA acetone-d6 was measured under static conditions using 16 increments and a sample maximum recovery time ranging from 1.8-3.2 s. FSPA ethanol-d2 was measured under 10 kHz MAS using 16 increments and a sample maximum recovery time ranging from 0.26-0.85 s. The temperature dependence of the relaxation times was fitted assuming a simple Arrhenius-like dependence of the motional correlation time, 𝜏 c , on temperature. The temperature dependence of 𝜏 c was parameterised using the parameters, Tmin and Ea: