Extended X-ray absorption fine structure analysis (EXAFS) has been use
d to study supported TiCl4/MgCl2 catalysts containing 1.8 wt.-% Ti. Ad
sorbed TiCl4 was found to exist on the MgCl2 surface as a dimeric comp
lex. The possible structures of dimeric TiCl4 complexes on the (100) f
ace of MgCl2 are discussed.