Rare earth metal bis(alkyl) complexes bearing amino phosphine ligands: Synthesis and catalytic activity toward ethylene polymerization
作者：Li, SH ; Miao, W; Tang, T (; Cui, DM; Chen, XS; Jing, XB
关键字：lanthanide; alkyl complex; ethylene; polymerization; phosphine
论文来源：期刊
具体来源：http://apps.webofknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=13&SID=V2hxdX
发表时间：2007年
Reactions
of neutral amino phosphine compounds HL1-3 with rare earth metal tris(alkyl)s,
Ln(CH2SiMe3)(3)(THF)(2), afforded a new family of organolanthanide complexes,
the molecular structures of which are strongly dependent on the ligand
framework. Alkane elimination reactions between 2-(CH3NH)-C6H4P(Ph)(2) (HL1)
and Lu(CH2SiMe3)(3)(THF)(2) at room temperature for 3 h generated mono(alkyl)
complex (L-1)(2)Lu(CH2SiMe3)(THF) (1). Similarly, treatment of
2-(C6H5CH2NH)-C6H4P(Ph)(2) (HL2) with Lu(CH2SiMe3)(3)(THF)(2) afforded
(L-2)(2)Lu(CH2SiMe3)(THF) (2), selectively, which gradually deproportionated to
a homoleptic complex (L-2)(3)Lu (3) at room temperature within a week.
Strikingly, under the same condition, 2-(2,6-Me2C6H3NH)-C6H4P(Ph)(2) (HL3)
swiftly reacted with Ln(CH2SiMe3)(3)(THF)(2) at room temperature for 3 h to
yield the corresponding lanthanide bis(alkyl) complexes L(3)Ln(CH2SiMC3)(2)(THF)(n)
(4a: Ln = Y, n = 2; 4b: Ln = Sc, n = 1; 4c: Ln = Lu, n = 1; 4d: Ln = Yb, n = 1;
4e: Ln = Tm, n = 1) in high yields. All complexes have been well
defined and the molecular structures of complexes 1, 2, 3 and 4b-e
were confirmed by X-ray diffraction analysis. The scandium bis(alkyl) complex
activated by AlEt3 and [Ph3C][B(C6F5)(4)], was able to catalyze the
polymerization of ethylene to afford linear polyethylene. (C) 2007 Elsevier B.V.
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