Octahedral Chromium(III) Complexes Supported by Bis(2-pyridylmethyl)amines: Ligand Influence on Coordination Geometry and Ethylene Polymerization Activity

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• 作者：Michael J. Carney ; Nicholas J. Robertson ; Jason A. Halfen ; Lev N. Zakharov ; and Arnold L. Rheingold
• 刊名：Organometallics
• 出版年：2004
• 出版时间：December 20, 2004
• 年：2004
• 卷：23
• 期：26
• 页码：6184 - 6190
• 全文大小：233K
• 年卷期：v.23,no.26(December 20, 2004)
• ISSN：1520-6041

文摘

This report describes the synthesis, structural characterization, and polymerizationbehavior of a series of chromium(III) complexes supported by bis(2-pyridylmethyl)alkylamine(BPA) ligands. The compounds are prepared in high yield by room-temperature reaction ofthe appropriate BPA ligand with CrCl₃(THF)₃. X-ray crystallographic studies reveal thatthe complexes' coordination geometries depend on the substituent at the 6-position of thepyridine ring. Unsubstituted ligands yield fac-{N-propyl-N,N-di(2-pyridylmethyl)amine}CrCl₃ (6A) and fac-{N-hexyl-N,N-di(2-pyridylmethyl)amine}CrCl₃ (6B), whereas 6-methyl-substituted ligands produce mer-{N-propyl-N,N-di(6-methyl-2-pyridylmethyl)amine}CrCl₃(6C) and mer-{N-hexyl-N,N-di(6-methyl-2-pyridylmethyl)amine}CrCl₃ (6D). Moreover, ethylene polymerization studies indicate that, upon activation by methylalumoxane, the facderivatives are 30-40 times more active than their mer counterparts.