Electronic Effect of Fluoro Substituents on Chromium(III) Complexes bearing β-Diketiminate Ligands for Ethylene Polymerization

Abstract:

A series of new chromium(III) complexes bearing fluoro-substituted β-diketiminate ligands have been synthesized and characterized by IR and elemental analyses. When activated by modified methylaluminoxane (MMAO), these Cr complexes exhibited moderate or high activities for ethylene polymerization (up to 370 g.mmol^-1.h^-1). Various reaction parameters such as reaction temperature and Al/Cr ratio were investigated in detail. Further more, it was found for the first time that the catalytic behaviors of Cr complexes can be greatly influenced by the electronic effect of fluoro substituents. The introduction of electron-withdrawing fluoro groups to ligands can improve the catalytic performances compared with those bearing alkyl groups, but incorporation of more fluoro atoms would then decrease the catalytic activities.

• Periodical: Advanced Materials Research (Volumes 476-478)
• Pages: 2201-2204
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.476-478.2201
• Online since: February 2012
• Authors: Guang Yong Xie, Xiang Zhang, Xiao Hang Xu, Ting Cheng Li, Ai Qing Zhang
• Keywords: Catalyst, Chromium(III) Complexes, Electronic Effect, Ethylene Polymerization, β-Diketiminate

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