Study of molecular motions and 14N quadrupolar coupling in 1,3- and 1,4- diethylpyridinium bromides using 13C and 14N relaxation time measurements

The internal and overall motions of 1,3- and 1,4-diethylpyridinium bromides have been studied by ¹³C relaxation. The enthalpies of activation for the rotation of the ethyl groups in positions 1 and 3 are deduced from the temperature dependence of the T₁ values of the methylene and methine carbons. The ¹⁴N quadrupolar relaxation time, T_q, together with ¹³C relaxation data provide an estimate of the ¹⁴N quadrupolar coupling constants.