The invention relates to a metal-free cyclopentadienide compound which can form a catalyst system in conjunction with a metallocene. Said catalyst system can be used for the polymerisation of olefins. The use of methylaluminoxane (MAO) or boronic compounds as co-catalysts can thus be dispensed with while still achieving high catalyst activity. The invention also relates to a method for producing said metal-free cyclopentadienide compound and the use thereof as a catalyst component in the production of polyolefins.
