| abstract |
The invention relates to a compound according to the formula (XR5-)(NR'4+), wherein X represents Si, Ge, Sn or Pb, the R groups may be the same or different, each being a monoanion chosen from the group comprising hydrogen, an alkyl group, an aryl group, an arylalkyl group, and the R' groups may be the same or different, each representing a hydrocarbon group containing 1-10 carbon atoms. The invention also relates to a process for the preparation of a compound of formula (XR¿5?-)(NR'4+), to an ion exchange process wherein the NR'¿4?+ is exchanged for another cation, and to the use of (XR¿5?-)(NR'4+) and the product of said ion exchange process as a cocatalyst in the polymerization of olefins. |