Synthesis and Anion Exchange Chemistry of Rhombohedral Li/Al Layered Double Hydroxides

A new Li/Al layered double hydroxide, [LiAl 2 (OH) 6 ]Cl·2H 2 O, having a rhombohedral layer stacking sequence has been synthesized by the reaction of the Al(OH) 3 polymorphs, bayerite and nordstrandite, with LiCl. As is the case with the hexagonal analogue, rhombohedral [LiAl 2 (OH) 6 ]Cl·2H 2 O has been found to readily undergo anion exchange reactions with a range of dicarboxylate anions although these reactions differ significantly in that no crystalline staging intermediates could be isolated. The rhombohedral stacking is maintained in the dicarboxylate derivatives.