C-13 AND AL-27 NMR RELAXATION STUDIES OF ETHYLALUMINUM DICHLORIDE

A new component of room-temperature molten salts, the dimer of ethylal uminum dichloride, EtAlCl(2), is examined with C-13 and Al-27 relaxati on methods at 7.05 and 11.75 T (35-70 degrees C). The methylene carbon undergoes scalar relaxation of the ''second kind'' as it is coupled t o a faster relaxing (quadrupolar) nucleus. Dimeric EtAlCl(2) undergoes a significant ''self-perturbation'' or liquid-state phase change betw een 50 and 60 degrees C, as evidenced by observed changes in its relax ation properties and J(AlC). The J(AlC) coupling constants are 191 (30 -50 degrees C) and 165 (55-70 degrees C) Hz. A liquid-state quadrupola r coupling constant (chi) of 71.9 MHz is determined for the EtAlCl(2) dimer using the dual spin probe method, assuming that the asymmetry pa rameter of the electric field gradient (eta) is zero. (C) 1994 Academi c Press, Inc.