PFG NMR experiments were carried out using a Bruker Avance Neo spectrometer and a 5mm H/F-BB diffusion probe at a magnetic field strength of 9.4 T ( 1 H Larmor frequency at 400 MHz) and 25ºC sample temperature. Diffusion experiments employed stimulated echo and longitudinal eddy-current delay (LED) bipolar gradient pulses for diffusion and two spoil gradients that yielded high-resolution, distortion-free NMR spectra 41 (ledpbgp2s Topspin pulse sequence). The diffusion gradients pulse durations, δ, were 1 millisecond each, with preemphasis, with powers varying from 17.1 mT.m -1 to 16.7 T.m -1 in 32 increments on an exponential scale. The gradients were calibrated using the self-diffusion coefficient of dry ethylene glycol 50 at 25ºC (8.87 x 10 -11 m 2 .s -1 ). Diffusion delays Δ ranged from 0.5 ms to 500 ms in 16 increments on a logarithmic scale. The sequence used two 100µs 8.5 mT.m -1 spoil pulses, and 100 µs gradient recovery times. The optimized 19 F 90º pulses on resonance was about 20 µs, i.e. ca. 12.5 kHz, and the recycling delay was set to 5 s.