Studies in the chemistry of quadrivalent germanium.

Strong base ion-exchange resins have been used to investigate the following systems. 1. Saturated solutions of GeCl4, in 1-12 N hydro- chloric, and hydrobromic, acids. 2. Solutions of Sn Cl[4] in 0-12 N hydrochloric acid. 3. Germanate solutions of pH 5-12 produced by dissolving GeO2 is suitable concentrations of sodium hydroxide. 4. Solutions of pH 2-12 containing GeO2 and three polyhydric alcohols, (mannitol, glycerol and ethanediol). 5. Solutions of pH 0-12 containing GeO[2] and three hydroxy acids, (lactic, tartaric and mucic). In system 1, the sharp rise in the solubility of GeO2, and more particularly GeCl4, in 6-8 M hydrochloric acid has been shown to be due to the formation of chloro-germanates such as Ge (OH)x Cl[5-x] or Ge (OH)[x] Cl [6-x] where x = 3 or 4. In system 2 it has been shown that appreciable quantities of SnCl5 exist in solutions of stannic chloride in hydrochloric acid, and that the existence of chloro-stannates is limited to dilute solutions, of low acidity. In system 3 it has been shown that the condensation of monogermanic acid to heptagermanic acid definitely proceeds via the intermediate formation of pentagermanate. In system 4, the existence of 1:1, 2:1 and 3:1 mannitol: germanium and glycerol: germanium complexes and 1:1 and 2:1 ethanediol: germanium complexes has been demonstrated; the degree of complexing increasing with increasing concentration of polyhydroxy compound and rise in pH. In the mannitol and glycerol systems at high concentration and low pH, polynuclear species have been shown to occur. In system 5, lactic acid has been shown to form 3:1, 2:1 and 1:1 complexes with germanium. With tartaric acid, a 1:1 complex predominates at low concentrations of tartrate, giving way to a 3:2 tartrate germanium complex at higher concentrations. In solutions containing much germanium, the formation of polynuclear species has been observed. The mucic acid: germanium system has features resembling those of the lactic acid system at low pH, the tartaric acid system at moderate pH, and the mannibol system at high pH.