Journal of Physical Chemistry, Vol.99, No.34, 12998-13001, 1995
NMR Relaxation Studies of Lithium-Aluminum Interaction in 1/2 LiCl-Ethylaluminum Dichloride Melts
Li-7 NMR relaxation studies provide evidence for the existence of scalar coupling between aluminum and lithium in 1:2 LiCl-ethylaluminum dichloride room temperature melts (mp approximate to -95 degrees C). Spin-lattice and spin-spin (Li-7) relaxation times (T-1 and T-2) are determined from -15 to 80 degrees C. At 5 degrees C and below, scalar relaxation of the second kind dominates the spin-spin relaxation mechanism, providing evidence that lithium is coupled to aluminum. The contribution of scalar coupling to spin-spin relaxation rates (R(2)) at higher temperatures is approximated by an Arrhenius function. The scalar R(2) values are used to calculate Li-7 quadrupolar spin-spin relaxation rates which are then used with R(1) values to determine correlation times and Li-7 nuclear quadrupole coupling constants.