STRUCTURE AND RELATIVE STABILITY OF THE ALUMINATE ANION STUDIED BY QUANTUM-CHEMICAL METHODS

The electronic structure and the total energies of various aluminate anions, possibly present in sodium aluminate solutions, have been calculated using the ab initio method and DV Xalpha method of quantum chemistry. The results are used to explain the experimental facts of the spectroscopic studies of sodium aluminate solutions. It has been found that the tetrahedral Al(OH)4- anion is more stable than the AlO2- and the planar Al(OH)4 anions in aqueous solutions, and the [(OH)3Al-O-Al(OH)3]2- anion is also relatively stable. The results of quantum chemical calculations are used also for the interpretation of the UV spectra of sodium aluminate solutions.