ZirconiumIV
Zirconium(IV) refers to the chemical state of zirconium where it possesses a +4 oxidation state. This is the most common and stable oxidation state for zirconium. Zirconium(IV) compounds are widespread in nature, with the most prominent mineral being zircon, zirconium silicate (ZrSiO4). In aqueous solutions, zirconium(IV) typically exists as the hexaaquazirconium(IV) ion, [Zr(H2O)6]4+, though it readily undergoes hydrolysis to form various polynuclear hydroxo complexes depending on the pH. Zirconium(IV) oxide, also known as zirconia (ZrO2), is a highly refractory ceramic material known for its exceptional hardness, chemical inertness, and high melting point, making it useful in applications such as dental implants, furnace linings, and as a component in solid oxide fuel cells. Zirconium(IV) chloride (ZrCl4) is a white crystalline solid that readily hydrolyzes in air and is used as a precursor in the synthesis of other zirconium compounds and in chemical vapor deposition. The chemistry of zirconium(IV) is characterized by its strong Lewis acidity and its tendency to form coordination complexes with oxygen-containing ligands.