Synthesis and characterization of titanium complexes bearing two beta-enaminoketonato ligands with electron-withdrawing groups and their behavior in ethylene polymerization

doi:10.1021/om700803u

CORC > 化学研究所 > 中国科学院化学研究所

	Synthesis and characterization of titanium complexes bearing two beta-enaminoketonato ligands with electron-withdrawing groups and their behavior in ethylene polymerization
	Ye, Wei-Ping 1,2; Zhan, Jie 1,2; Pan, Li 1; Hu, Ning-Hai ; Li, Yue-Sheng 1
刊名	ORGANOMETALLICS
	2008-08-11
卷号	27 期号:15 页码:3642-3653
ISSN号	0276-7333
DOI	10.1021/om700803u
英文摘要	A series of new titanium complexes with two asymmetric bidentate beta-enaminoketonato (N,O) ligands (4b-t), [RN=CCF3)CHC(t-BU)O](2)TiCl2 (4b, R = -C6H4F(o); 4c, R = -C6H4F(m);4d, R = -C6H4F(p); 4e, R = - C6H3F2(2,3); 4f, R = -C6H3F2(2,4); 4g, R = -C6H3F2(2,5); 4h, R = -C6H3F2(2,6); 4i, R = -C6H3F2(3,4); 4j, R = -C6H3F2(3,5); 4k, R = -C6H2F3(2,3,4); 4l, R = -C6H2F3(3,4,5); 4m, R = -C6H4CF3(o); 4n, R =-C6H4CF3(m); 4o, R = -C6H4CF3(p); 4p, R = -C6H4Cl(p); 4q, R = -C6H4I(p); 4r, R = -C6H4NO2(P); 4s, R = -CH2C6H5; 4t, R = -C6H11), have been synthesized and characterized. X-ray crystal structures suggest that complexes 4a-d, 4j, and 4m all adopt a distorted octahedral geometry around the titanium centers. Two chlorine atoms in complexes 4a-d and 4j are in cis-configuration, while those of complex 4m are trans. NMR spectra and X-ray structure analyses reveal that the conformational isomers of some complexes, such as 4b, in which the two beta-enaminoketonato ligands bear asymmetrical N-phenyl rings, exist both in solution and in solid state. With modified methylaluminoxane (MMAO) as a cocatalyst, complexes 4b-1 and 4n-q are highly active toward ethylene polymerization and produce high molecular weight polyethylenes. The catalytic activities are significantly enhanced by introducing electron-withdrawing groups (EWG), such as fluorine and chlorine atom(s) or the trifluoromethyl group, into suitable positions on the N-aryl rings. The titanium complex 4m is inactive toward ethylene polymerization due to the trans-configuration of the two chlorine atoms. In addition, the titanium complexes display low catalytic activity for ethylene polymerization only if the N-substituents are not aromatic.
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000258226100006
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/64291]
专题	中国科学院化学研究所
通讯作者	Li, Yue-Sheng
作者单位	1.Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Polymer Phys & Chem, Changchun 130022, Peoples R China 2.Chinese Acad Sci, Grad Sch, Changchun Branch, Beijing 100864, Peoples R China
推荐引用方式 GB/T 7714	Ye, Wei-Ping,Zhan, Jie,Pan, Li,et al. Synthesis and characterization of titanium complexes bearing two beta-enaminoketonato ligands with electron-withdrawing groups and their behavior in ethylene polymerization[J]. ORGANOMETALLICS,2008,27(15):3642-3653.
APA	Ye, Wei-Ping,Zhan, Jie,Pan, Li,Hu, Ning-Hai,&Li, Yue-Sheng.(2008).Synthesis and characterization of titanium complexes bearing two beta-enaminoketonato ligands with electron-withdrawing groups and their behavior in ethylene polymerization.ORGANOMETALLICS,27(15),3642-3653.
MLA	Ye, Wei-Ping,et al."Synthesis and characterization of titanium complexes bearing two beta-enaminoketonato ligands with electron-withdrawing groups and their behavior in ethylene polymerization".ORGANOMETALLICS 27.15(2008):3642-3653.