Oxidation state +4 occupies a leading position in titan […]
Oxidation state +4 occupies a leading position in titanium chemistry, but compounds with oxidation state +3 are also common. Because of this high oxidation state, the covalent bonds in many titanium compounds are highly dense.
The star sapphire and ruby's stellar brilliance come from the titanium dioxide impurities they contain. Titanate is a compound that uses titanium dioxide as a raw material. Barium titanate has piezoelectricity, so it can be used to make acousto-optic converters. Alcohol reacts with titanium tetrachloride to produce titanium ester, which can be used to make waterproof fibers.
Titanium nitride (TiN) has a hardness equivalent to that of sapphire and emery (Mohs hardness 9.0), so it can be used as a coating for various cutting tools, such as drill bits. Its other applications include golden paint for decoration and diffusion barrier layer at the interface of copper wires in the manufacture of semiconductor devices.
Titanium tetrachloride (titanium chloride (IV), TiCl4) is a colorless liquid and an intermediate in the manufacturing process of titanium dioxide pigments. As a Lewis acid, titanium tetrachloride is widely used in organic chemical reactions, such as the Mukoyama aldol reaction. Titanium has another chloride with a lower oxidation number, titanium trichloride (titanium(III) chloride, TiCl3), which is used as a reducing agent.
Titanocene dichloride is an important carbon-carbon bond formation catalyst. Titanium isopropoxide is used in the Sharpless asymmetric epoxidation reaction. Other compounds also include titanium bromide (used in metallurgy, super alloys, and high-temperature wires and coatings) and titanium carbide (used in high-temperature cutting tools and coatings).