Gallium hydrolysis reactions

Gallium hydrolyses to a greater extent than aluminium, with the onset of hydrolysis reactions occurring just above a pH of 1. In fact, even though aluminium has the smallest ionic radius of this series of metals, it has the weakest hydrolysis species and oxide/hydroxide phases. This is due to the presence of stabilising d-orbitals in the heavier metals, gallium, indium and thallium(III). 

Like their aluminum counterparts, gallium alkoxides are susceptible to hydrolysis, giving Ul-defined products. Methanolysis of hydrated Ga + ions produces Ga(OMe) + and Ga(OMe)2+ in solvated forms, as well as polymeric complexes. Ga(OPh)3 reacts with boiling MeOH or EtOH to form the corresponding alkoxide. Reaction of the trialkoxide compounds with other metal alkoxides, for example, LiOR, results in the formation of four-coordinate complex anions of the type [Ga(OR)4] A recent review of sesquihahdes/oxides... 

Morin, the coloring matter of fustic, is 3,5,7,2, 4 -pentahydroxy flavone (I). Its alcohol solutions react with aluminum salts in neutral or acetic acid solution to give an intense green fluorescence in daylight and ultraviolet light. The fluorescence is due to the formation of a colloidally dispersed inner complex aluminum salt of morin with the probable structure (II), or to an adsorption compound of morin with alumina. Beryllium, indium, gallium, thorium and scandium salts also form fluorescent compounds with morin. The pH of the system has much influence in these reactions. The only metal ion whose reaction with morin is independent of pH is Zr+ or its hydrolysis product (compare page 519). 

The most recent hydrolysis data for gallium is also the most reliable. The hydrolysis of gallium can be described by reaction (2.5) (M = Ga, p = l) where q, the... 

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