Addition Compounds of Titanium Tetrachloride

Besides hydro-chlorotitanic acid and its salts, titanium forms numerous addition products with ammonia and other bases, as well as with various acid chlorides.

With ammonia there are the compounds TiCl₄.8NH₃ and TiCl₄.6NH₃, and perhaps TiCl₄.4NH₃.

The compound TiCl₄.8NH₃ is formed as a yellow powder 2 when dry ammonia reacts with titanium tetrachloride suspended in dry ether, and also when the tetrachloride is shaken for twelve hours with liquid ammonia. It is unstable, readily giving up ammonia. The compound TiCl₄.6NH₃ results when gaseous ammonia reacts with the tetrachloride vapour; it is an amorphous, dark yellow powder which in presence of a little moisture is readily hydrolysed, yielding titanic acid, ammonium chloride, and ammonia. Liquid ammonia reacts with either of these compounds, yielding dark yellow titanamide, Ti(NH₂)₄, and ammonium chloride.

A pyridine compound, TiCl₄.6C₅H₅N, exists, analogous to the ammonia compound of similar composition; and compounds with acid chlorides, such as TiCl₄.POCl₃, TiCl₄.2POCl₃, TiCl₄.PCl₃, TiCl₄.PCl₅, as well as additive compounds with numerous types of organic compounds, are known.

Organic substitution products of titanium tetrachloride have been prepared by Dilthey and his collaborators. For example, acetyl-methylacetone forms the compound [Ti(OCMe: CMeAc)₃Cl]2.TiCl₄ or [Ti(OCMe: CMeAc)₃]2TiCl₆. Such compounds are called titanonium salts; and there exist corresponding siliconium and boronium compounds.