Patent ID: 7300904

Claim:
A catalyst system for the oligomerisation of olefins, the system comprising a mixed heteroatomic ligand, which ligand includes at least three heteroatoms of which at least one is sulfur and at least 2 heteroatoms are not the same, and a chromium, wherein none of the non-carbon based heteroatoms in the ligand is directly bonded to any of the other non-carbon based heteroatoms and the ligand is selected from the following ligand types: (a) R 1 A(R 2 BR 3 )(R 4 CR 5 ) wherein R 1 , R 3 and R 5 may be hydrogen or be independently selected from the groups consisting of alkyl, aryl, aryloxy, halogen, nitro, alkoxycarbonyl, carbonyloxy, alkoxy, aminocarbonyl, carbonylamino, dialkylamino, or derivatives thereof, or aryl substituted with any of these substituents; R 2 and R 4 may be the same or different and are C 1 to C 15 hydrocarbyls; A is nitrogen or phosphorous; and B and C are sulfur; and (b) R 1 A(R 2 BR 3 R 4 )(R 5 CR 6 ) wherein R 1 , R 3 , R 4 , and R 6 may be hydrogen or independently be selected from the groups consisting of alkyl, aryl, aryloxy, halogen, nitro, alkoxycarbonyl, carbonyloxy, alkoxy, aminocarbonyl, carbonylamino, dialkylamino, or derivatives thereof, or aryl substituted with any of these substituents; R 2 and R 5 may be the same or different and are C 1 to about C 15 hydrocarbyls; A and B are independently nitrogen or phosphorous; and C is sulfur; and (c) A(R 1 BR 2 R 3 )(R 4 CR 5 ) wherein R 2 , R 3 , and R 5 may be hydrogen or independently be selected from the groups consisting of alkyl, aryl, aryloxy, halogen, nitro, alkoxycarbonyl, carbonyloxy, alkoxy, aminocarbonyl, carbonylamino, dialkylamino, or derivatives thereof, or aryl substituted with any of these substituents; R 1 and R 4 may be the same or different and are C 1 to about C 15 hydrocarbyls; B is nitrogen or phosphorous; and A and C are sulfur; and (d) A(R 1 BR 2 R 3 )(R 4 CR 5 R 6 ) wherein R 2 , R 3 , R 5 and R 6 may be hydrogen or independently be selected from the groups consisting of alkyl, aryl, aryloxy, halogen, nitro, alkoxycarbonyl, carbonyloxy, alkoxy, aminocarbonyl, carbonylamino, dialkylamino, or derivatives thereof, or aryl substituted with any of these substituents; R 1 and R 4 may be the same or different and are C 1 to about C 15 hydrocarbyls; B and C are independently nitrogen or phosphorous; and A is sulfur.