Spin-Lattice relaxation times (T1) were measured using the inversion recovery sequence , spin-spin relaxation times (T2) were measured using the Carr-Purcell-Meiboom-Gill (CPMG) sequence and the resonance linewidths were obtained by Fourier transforming the free induction decay (FID) of the resonance. T1, δ measurements at17.1 T were performed using a spin-locking sequence .