TiIV

TiIV denotes titanium in the +4 oxidation state, commonly written as Ti4+ or Ti(IV) in chemical literature. The term TiIV is used to indicate titanium bound in compounds or complexes where the oxidation state is four, a prevailing state for titanium in inorganic chemistry.

In this oxidation state, titanium is a hard, highly charged center that forms a wide range of oxide- and halide-containing compounds. In aqueous solutions, Ti(IV) behaves as a strong Lewis acid and undergoes rapid hydrolysis, producing oxo and hydroxy species. Depending on pH, these species can evolve toward hydrated titanium dioxide (TiO2) precipitates, while more complex polymeric oxo species can form under various conditions.

Common Ti(IV) compounds include titanium tetrachloride (TiCl4), a volatile liquid that hydrolyzes violently in water; titanium alkoxides such as Ti(OR)4 (where OR denotes an alkyl group) used as precursors for sol-gel processing and coatings; and titanium dioxide (TiO2), a solid oxide employed as a white pigment and as a photocatalyst. Organometallic Ti(IV) complexes, such as titanocene dichloride, have been studied for medicinal applications, including anticancer research.

Applications of Ti(IV) chemistry are broad. Ti(IV) compounds serve as precursors for the synthesis of titanium-based ceramics and coatings, and TiO2 is ubiquitous in pigments, sunscreens, and photocatalytic technologies. In catalysis, supported Ti(IV) species are central to certain Ziegler–Natta polymerization systems used for olefin polymerization.

Safety considerations center on corrosivity and hydrolysis of TiCl4, which releases HCl, requiring proper containment and handling. TiO2 dust, while relatively inert, poses inhalation hazards. Proper chemical hygiene and protective equipment are standard when working with Ti(IV) compounds.