Über kristallines Chrom(III)hydroxid. I

When hydroxide ions are added to a solution of Cr(H2O)63+ ions at low temperature a well crystallized chromium hydroxide hydrate is formed, corresponding to the formula [Cr(OH)3-(H2O)3]∞. Its structure is the inverse of bayerite type, two thirds of the octahedral M3+ positions being vacant. It loses water easily and turns into a totally amorphous hydroxide of variable water content. An amorphous hydroxide is also obtained when solutions are alkalized at higher temperatures or when aged solutions (containing polynuclear complexes) are used.

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