Ethylene oligomerization catalyst systems having enhanced selectivity

摘要

Disclosed herein is a catalyst system for selective oligomerization of ethylene, which comprises a P—C—C—P frame-work ligand, which is (R1)(R2)P—(R5)CHCH(R6)—P(R3)(R4), and a chromium-based metal compound. Also disclosed is a method of greatly enhancing the activity and selectivity of oligomerization, such as trimerization or tetramerization, using a ligand having a specific steric arrangement structure.