Metal (Mg, Fe, Co, Zr and Ti) complexes derived from aminosilyl substituted aminopyridinato ligand: synthesis, structures and ethylene polymerization behaviors of the group 4 complexesElectronic supplementary information (ESI) available: More crystallographic data of this paper. CCDC 858901-858903 and 859331-859332. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c2dt30463e

• Main Authors: Duan, Xin-E, Yuan, Shi-Fang, Tong, Hong-Bo, Bai, Sheng-Di, Wei, Xue-Hong, Liu, Dian-Sheng
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c2dt30463e

Lithium N -[( N , N -dimethylamino)dimethylsilyl]-2-pyridylamidate ( 2 ) was prepared from the reaction of new compound N -[( N , N -dimethylamino)dimethylsilyl]-2-pyridylamine ( 1 ) and LiBu n . Treatment of the lithium salt ( 2 ) with an equal equivalent of MgBr 2 (THF) 2 , FeCl 2 and CoCl 2 afforded the corresponding dinuclear complexes 3 , 4 , and 5 , in which metal atoms possess similar trigonal bipyramidal geometries and each ligand functions as a bimetallic bridging binding aminopyridinato moiety with N-donation from the dimethylamino group. While the stoichiometric reaction of 2 with ZrCl 4 gave the mononuclear zirconium complex ( 6 ); the seven coordinated zirconium atom adopts a distorted pentagonal bipyramid geometry and the ligand acts as monoanionic 2 -aminopyridinato moiety with the pendant arm coordinated via N(CH 3 ) 2 . The reaction of 2 with one equivalent of TiCl 4 (THF) 2 produced the interesting dinuclear titanium complex ( 7 ) owing to the elimination of a ( N , N -dimethylamino)dimethylsilyl group from the original ligand, and the two titanium centers present different coordination geometries. The molecular structures of the crystalline metal complexes 3-7 have been confirmed by X-ray single crystal diffraction analysis. Upon activation with methylaluminoxane (MAO), both complexes 6 and 7 exhibited moderate catalytic activities toward ethylene polymerization and produced high molecular weight polyethylenes with broad molecular weight distributions. Magnesium, iron, cobalt, zirconium and titanium complexes derived from the new monoanionic aminosilyl substituted aminopyridinato ligand have been prepared and characterized.