AbstractThe11B and2H spin–lattice relaxation times,T1, were measured for sodium cyanoborohydride (BH3CN−) and sodium cyanoborodeuteride (BD3CN−) in methanol–ethylene glycol solution as a function of temperature. Both11B and2HT1minima were observed, yielding11B and2H nuclear quadrupolar coupling constants, χ, of 766 and 104 kHz, respectively. Measurement of the14NT1at 300 K gave a χ(14N) value of 2.8 MHz. Electric field gradients were calculated usingab initiomolecular orbital theory, in order to obtain theoretical11B,14N and2H χ values. The values of 847 kHz, −3.25 MHz and 141 kHz for11B,14N and2H, respectively, are larger than those found