Decomposition of organo‐titanium halides

Pure tetravalent organo‐titanium halides and those titanium alkyls which are formed by a reaction of TiCl4 + organometallic compounds, are unstable and subject to bimolecular disproportionation into 2 TiCl3, an alkane and an olefin, provided an H‐atom on a β‐C‐atom is present in the alkyl group. On the other hand, tetravalent titanium‐alkyls lacking this H‐atom are relatively stable (e.g. TiCl3CH3 and neopentyl‐titanium‐trichloride). Chemical evidence has also been advanced in support of two other, subsidiary, bimolecular reactions of titanium alkyls in which, in a concerted reaction, the Ti‐C bonds are broken without previous atom migration taking place in the alkyl groups. In one of these subsidiary reactions the alkyl groups bonded to titanium get directly linked up, with formation of a saturated hydrocarbon and TiCl3. In the other, a titanium alkyl reacts with TiCl4 to give an alkylhalide and TiCl3. By performing the disproportionation reaction of TiCl3CD3 in heptane, or of titanium alkyls in deuterated cyclohexane, it is demonstrated that no reaction with aliphatic solvents occurs.