NMR investigation of orientationally disordered NaCN and KCN

Nitrogen-14 NMR spin–lattice relaxation times are reported for the cubic phases of NaCN and KCN. The 14N T1 values of both compounds increase as temperature increase with apparent activation energies of 1.40±0.10 and 0.78±0.05 kcal/mole, respectively. The measured 14N T1 values indicate that T1≫T2 and that the rotational correlation times for cyanide reorientation are at least two orders of magnitude shorter than indicted in previous 14N studies. Carbon-13 T1 values for KCN decrease with increasing temperature with an apparent activation energy of 1.38±0.2 kcal/mole and are interpreted assuming that the spin rotation mechanism dominates. Reduced correlation time τ2 and τJ derived from the 14N and 13C data, respectively, are compared with those calculated using the J-diffusion model which is quite successful for liquids.