Carbocations forming from the reaction of alkylbenzenes with TaCl 5 –CH 2 Cl 2 : isolation and X-ray structures

Tantalum pentachloride–methylene chloride system performs C–C and C–H bond cleavages on alkylbenzenes producing the 5,7-diisopropyl-1,3,3-trimethylindan-1-yl cation from 1,3,5-triisopropylbenzene, and the 9,10-dihydro-9-anthryl cation from both 1,2,4,5-tetramethylbenzene and 1,2,3,5-tetramethylbenzene both having TaCl6– as a counteranion, and they have been characterized by X-ray analysis.