Synthesis and structure of (pi-arene)titanium(II) haloaluminate complesex with diarylmethane ligands

Novel (arene)titanium(II) haloaluminate complexes (eta(6)-arene)Ti[(mu-X)(2 )AlX2](2) (X = Cl, Br) were obtained from (eta(6)-benzene)Ti[(mu-X)(2)AlX2] (2) ( X = Cl, Br) complexes by ligand exchange reactions with bis(pentameth ylphenyl) methane and dimesitylmethane. The [eta(6)- 1,2,3,4,5-pentamethyl- 6-(2,3,4,5,6-pentamethylbenzl)benzene]Ti[(mu-X)(2)AlX2](2) (X = Cl, Br) and [eta(6)-1,3,5-trimethyl-2-(2,4,6-trimethylbenzyl) benzene]Ti[(mu-Br)(2)AlB r2](2) complexes containing titanium coordinated to only one of the two phe nyl rings were obtained and their crystal structures were determined, (eta( 6)-Benzene)Ti [(mu-Cl)(2)AlCl2](2) and dimesitylmethane afforded the (eta(o )-mesitylene)Ti[(mu-Cl)(2)AlCl2](2) complex which is isotypic with the know n bromo analogue. This product shows that Friedel-Crafts scission of aryl-a lkyl bonds occurs in such systems even under mild conditions.