chemistry Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...

, titanate usually refers to

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

s composed of titanium oxides, or

oxide An oxide () is a chemical compound containing at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion (anion bearing a net charge of −2) of oxygen, an O2− ion with oxygen in the oxidation st ...

s containing the

titanium Titanium is a chemical element; it has symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...

element. Together with niobate, titanate salts form the Perovskite group. In some cases, the term is used more generally for any titanium-containing

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

, e.g. iCl₆sup>2− and i(CO)₆sup>2−. This article focuses on the oxides. Many kinds of titanium oxides are known, and some are commercially important. Typically these materials are white,

diamagnetic Diamagnetism is the property of materials that are repelled by a magnetic field; an applied magnetic field creates an induced magnetic field in them in the opposite direction, causing a repulsive force. In contrast, paramagnetic and ferromagn ...

, high-melting, and insoluble in water. They are often prepared at high temperatures, e.g. using tube furnaces, from titanium dioxide. In virtually all cases, titanium achieves octahedral coordination geometry..

Orthotitanates

Orthotitanates have the formula M₂TiO₄, where M is divalent. An example of such a material is magnesium titanate (Mg₂TiO₄), which adopts the spinel structure. Li₂TiO₃ is not considered an orthotitanate since it adopts the rock-salt structure and does not feature an identifiable titanium anion. Orthotitanates almost never feature identifiable TiO₄⁴⁻ centres, an exception being Ba₂TiO₄.

Titanic acid and its esters

Also called orthotitanic acid or titanium hydroxide, the substance H₄TiO₄ is called titanic acid. This material, which is not well defined, is obtained by hydrolysis of TiCl₄. The solid is unstable with respect to loss of water and formation of titanium dioxide.

Esters In chemistry, an ester is a chemical compound, compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds c ...

of orthotitanic acid are known, however; one example being titanium isopropoxide. Esters derived from smaller alcohols adopt more complex structures wherein titanium does achieve octahedral coordination, e.g. Ti₄(OCH₃)₁₆ or titanium tetramethoxide. It is a weak acid, if it can be isolated.

Metatitanates

The metatitanates have the formula MTiO₃, where again M is divalent. They do not feature discrete TiO₃²⁻ centres. Some, like the commercially important mineral ilmenite (FeTiO₃), crystallize in the hexagonal close packing motif seen in

corundum Corundum is a crystalline form of aluminium oxide () typically containing traces of iron, titanium, vanadium, and chromium. It is a rock (geology), rock-forming mineral. It is a naturally transparency and translucency, transparent material, but ...

. Alternatively, some materials with the formula MTiO₃ crystallize in the motif known as perovskite, which is also the name of the mineral form of calcium titanate (CaTiO₃). Barium titanate is one such perovskite-structured titanate with ferroelectric properties.

Complex titanates

More complex titanates are also known, such as

bismuth titanate Bismuth titanate or bismuth titanium oxide is a solid inorganic compound of bismuth, titanium and oxygen with the chemical formula of Bi12TiO20, Bi 4Ti3O12 or Bi2Ti2O7. Synthesis Bismuth titanate ceramics can be produced by heating a mixture o ...

, Bi₄Ti₃O₁₂..

References

{{Titanium compounds Transition metal oxyanions Oxometallates