Interaction Between Organic Acids and Aluminium Hydroxide

The acetic acid and benzoic acids are chosen as model molecules to study their possible interactions with aluminium hydroxide. Three schemes have been examined for interaction, namely Van der Waal, unidentate complex and bidentate complex interactions. B3LYP/6-31g(d,p) is used to calculate optimized structure, total dipole moment, HOMO/LUMO band gap energy and vibrational frequencies. Results indicate that band gap energy has decreased as a result of interaction while the bond length LC-O decreased with an increase in L-C=O bond length. The C=O asymmetric stretching of the carboxyl group is shifted toward lower wavenmbers as a result of interaction between the studied acids and aluminium hydroxide.