Zhao X, Wang J, Liu D, Kong W, Zhang J. Chromium Ethylene Tri-/Tetramerization Catalysts Supported by Iminophosphine Ligands.
ACS OMEGA 2023;
8:34549-34556. [PMID:
37780000 PMCID:
PMC10536060 DOI:
10.1021/acsomega.3c03356]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Accepted: 08/21/2023] [Indexed: 10/03/2023]
Abstract
A new class of highly active ethylene tri-/tetramerization chromium catalysts supported by iminophosphine ligands has been studied. The impact of electronic and steric changes of these ligands on selectivity and activity has been investigated by varying P- and/or N-substituents. Upon activation with MMAO, the ligand bearing a P-cyclohexyl group displayed a high activity of 307 kg/(g Cr/h) with a high trimerization selectivity of 92.6%. Decreasing the steric hindrance of N-aryl group led to a decrease in 1-hexene selectivity (74.5%), producing more 1-octene (10.3%). X-ray diffraction analysis verifies that the ligands coordinate with the chromium center in a κ2-P,N mode.
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