Predicting Guest Orientations in Layered Double Hydroxide Intercalates

Molecular mechanics have been used to rationalize the structures of the layered double hydroxide intercalates [LiAl 2 (OH) 6 ]Cl, [LiAl 2 (OH) 6 ]Br, and [LiAl 2 (OH) 6 ]NO 3 . The simulations showed that calculated lowest energy structures were in good agreement with the experimentally determined structures and were able to explain the positional disorder of the NO 3 - guest anions found in the structure of [LiAl 2 (OH) 6 ]NO 3 . Furthermore, the calculations also proved to be a useful predictive tool for the interlayer spacing and consequently the guest orientation in the related intercalates [LiAl 2 (OH) 6 ] 2 CO 3, [LiAl 2 (OH) 6 ] 2 SO 4, and [LiAl 2 (OH) 6 ] 2 C 2 O 4, for which the structures have not been determined by conventional diffraction techniques.