Advances of Chromium(III)-Based Catalysts with Multidentate Heteroatomic Ligands for 1-Hexene Production

According to the various multidentate heteroatomic ligands(based oxygen,nitrogen, phosphorus,mixed N and P,mixed N and S donors, composition, activity and overall selectivity to 1-hexene of chromium-based trimerization catalysts were reviewed. Commercial application foreground of these catalyst systems was also expected.It was found that effect of ligand structure on activity and selectivity for ethylene trimerization was the most predominant.The PNP （(Ph2P)2N(cyclopentyl)）ligands were prepared using inexpensive reagents and gave the corresponding complexes in high yields.Due to the inexpensive ligands coupled with low MAO （methyl aluminum oxide）requirements and high activity and selectivity of these systems, this has positive implication for a commercial process to 1-hexene.