Field-dependent relaxation in 207Pb NMR

207Pb spin-lattice relaxation (T1) studies at magnetic fields of 2.35 and 7.05 T of Pb(NO3)2, PbMe, and PbMe3Cl indicate field dependence only for PbMe3Cl. Variable-temperature studies on this compound demonstrate the interplay between the spin-rotation (SR) and the chemical-shift anisotropy (CSA) mechanisms. The relaxation is dominated by SR at 2.35 T and by CSA at 7.05 T. The activation energies are −11.8 and 18.4 kJ · mol−1, respectively, values close to those previously reported for PbCl4.