| abstract |
The present invention relates to a catalyst composition and process for the di-, tri- and / or tetramerization of ethylene, wherein the catalyst composition comprises a chromium compound, general structure (A) R 1 R 2 P—N (R 3) -P (R 4 ) -N (R 5) -H or (B) R 1 R 2 P -N (R 3) -P (R 4) -N (R 5) -PR 6 R 7 Or any cyclic derivative of (A) and (B), and a cocatalyst or activator, wherein at least one of the P and N atoms of the PNPN-unit or PNPNP-unit is a ring system It is a member and this ring system is formed from one or more constituent compounds of structure (A) or (B) by substitution. |