 A striking example is found with zirconium(IV).Because of the high oxidation state, salts of Zr4+ are extensively hydrolyzed in water even at low pH.The compound originally formulated as ZrOCl2·8H2O was found to be the chloride salt of a tetrameric cation [Zr4(OH)8(H2O)16]8+ in which there is a square of Zr4+ ions with two hydroxide groups bridging between Zr atoms on each side of the square and with four water molecules attached to each Zr atom.