Hydrates des halogenures de gallium. II Spectroscopie de vibration des complexes coordinés GaX₃^•H₂O (X = Cl ou Br)

Abstract

GaX 3 .H 2 0 (X = Cl, Br) is a tetrahedrally coordinated adduct of gallium. From vibrational spectra of hydrates, deuteriates, and mixed crystals, bands assignments are made. Spectra are consistent with OGaX 3 (C 3υ ) and H 2 O (C 2υ ) groups but the maximum symmetry of the whole complex (C s ) is lowered to C 1 owing to the nonequivalence of the two O—H of the water molecule. The "Ga—O" stretching modes are located and the valence force field of OGaX 3 skeleton is computed. The coordination bond is strong and the halogen–metal bonds are shorter than in the tetrahalogenogallate ions.