In inorganic chemistry, olation is the process by which metal ions form polymeric oxides in aqueous solution.
In the resulting 5+ ion, the remaining water and hydroxo ligands are highly acidic and the ionization and condensation processes can continue at still higher pHs.
This hydroxy complex can undergo olation:[6] The "diol" (second reaction) is favored and is accelerated by heat and high pH.
The balance of these two factors, temperature and pH of the solution, along with the concentration of chromium(III), influence the continued polymerization of [(Cr(H2O)4)2(μ-OH)2]4+.
The actual chemistry of [Cr(H2O)6]3+ is more complex in the tanning bath rather than in water due to the presence of a variety of ligands.