text: has a "closed" electronic shell, with the same number of electrons as the noble gas argon. The tetrahedral structure for  is consistent with its description as a d0 metal center () surrounded by four identical ligands. This configuration leads to highly symmetrical structures, hence the tetrahedral shape of the molecule.  adopts similar structures to  and ; the three compounds share many similarities.  and  react to give mixed halides , where x = 0, 1, 2, 3, 4. Magnetic resonance measurements also indicate that halide exchange is also rapid between  and .
  is soluble in toluene and chlorocarbons. Certain arenes form complexes of the type .  reacts exothermically with donor solvents such as THF to give hexacoordinated adducts. Bulkier ligands (L) give pentacoordinated adducts .
  Production
  is produced by the chloride process, which involves the reduction of titanium oxide ores, typically ilmenite (), with carbon under flowing chlorine at 900 °C. Impurities are removed by distillation.
  The coproduction of  is undesirable, which has motivated the development of alternative technologies. Instead of directly using ilmenite, "rutile slag" is used. This material, an impure form of , is derived from ilmenite by removal of iron, either using carbon reduction or extraction with sulfuric acid. Crude  contains a variety of other volatile halides, including vanadyl chloride (), silicon tetrachloride (), and tin tetrachloride (), which must be separated.
  Applications