Formula TiO Melting point 1,750 °C Appearance bronze crystals Flash point Non-flammable | Molar mass 63.866 g/mol Density 4.95 g/cm³ Crystal structure cubic | |
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Titanium(II) oxide (TiO) is an inorganic chemical compound of titanium and oxygen. It can be prepared from titanium dioxide and titanium metal at 1500 °C. It is non-stoichiometric in a range TiO0.7 to TiO1.3 and this is caused by vacancies of either Ti or O in the defect rock salt structure. In pure TiO 15% of both Ti and O sites are vacant. Careful annealing can cause ordering of the vacancies producing a monoclinic form which has 5 TiO units in the primitive cell that exhibits lower resistivity. A high temperature form with titanium atoms with trigonal prismatic coordination is also known. Acid solutions of TiO are stable for a short time then decompose to give hydrogen:
Ti2+ + H+ → Ti3+ + ½ H2Evidence has been obtained for the presence of the diatomic molecule TiO in the interstellar medium. TiO shows strong bands in the optical spectra of cool (M-type) stars.