2-(1H-2-Benzimidazolyl)-6-(1-(arylimino)ethyl)pyridyl Iron(II) and Cobalt(II) Dichlorides: Syntheses, Characterizations, and Catalytic Behaviors toward Ethylene Reactivity

详细信息    查看全文

• 作者：Liwei Xiao^† ; ^‡ ; ; Rong Gao^‡ ; ; Min Zhang^‡ ; ; Yan Li^‡ ; ; Xiaoping Cao*^† ; ; Wen-Hua Sun*^† ; ^&#
• 刊名：Organometallics
• 出版年：2009
• 出版时间：April 13, 2009
• 年：2009
• 卷：28
• 期：7
• 页码：2225-2233
• 全文大小：192K
• 年卷期：v.28,no.7(April 13, 2009)
• ISSN：1520-6041

文摘

A series of tridentate N iron(II) and cobalt(II) dichloride complexes bearing 2-(1H-2-benzimidazolyl)-6-(1-(arylimino)ethyl)pyridines were synthesized and characterized by elemental and spectroscopic analyses. Single-crystal X-ray diffraction studies of representative examples of the cobalt and iron complexes confirm distorted bipyramidal geometry around the metal center. Upon coordination of a methanol solvent molecule, a geometry change to distorted octahedral was observed. The steric and electronic effects on catalytic activity are evaluated for different substituents in the arylimino part of the ligand: Me, Et, ⁱPr, Cl, and Br in ortho- and Me and H in para-position. On treatment with methylaluminoxane (MAO) or modified MAO (MMAO), the iron(II) complexes exhibited good activities of up to 10⁶ g·mol⁻¹(Fe)·h⁻¹ for ethylene oligomerization and moderate activities for polymerization, while cobalt(II) complexes showed moderate activities for ethylene dimerization. The best activities were observed with iron complexes with bulky ⁱPr groups in the aryl moiety. In comparison to the analogues containing the 2-(1-alkyl-2-benzimidazolyl)-6-(1-(arylimino)ethyl)pyridines, the iron complexes bearing 2-(1H-2-benzimidazolyl)-6-(1-(arylimino)ethyl)pyridines showed the best activity toward ethylene reactivity.