New rare earth metal bis(alkyl)s bearing an iminophosphonamido ligand. Synthesis and catalysis toward highly 3,4-selective polymerization of isoprene | |
Li, Shihui1,2; Miao, Wei1,2; Tang, Tao1; Dong, Weimin1; Zhang, Xuequan1; Cui, Dongmei1 | |
Corresponding Author | Cui, Dongmei(dmcui@ciac.jl.cn) |
2008-02-25 | |
Source Publication | ORGANOMETALLICS
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ISSN | 0276-7333 |
Volume | 27Issue:4Pages:718-725 |
Abstract | Newrareearth metal bis(alkyl) complexes [(NPNPh)Ln(CH2SiMe3)(2)(THF) (NPNPh:N(Ph)PPh2=NC6H2Me3-2,4,6; Ln = Sc (3a), Ln = Y (3b), Ln = Lu (3c)) and [(NPNPy)Sc(CH2SiMe3)(2)(THF)1 (NPNPY = N(Py)PPh2=NC6H2Me3-2,4,6) (3d)) have been prepared via protonolysis reaction between rare earth metal tris(alkyl)s and the corresponding iminophosphonamines. Complexes 3a-d are analogous monomers of THF solvate. Each metal ion coordinates to a eta(2)-chelated NPN ligand and two cis-located alkyl groups, adopting tetrahedron geometry. The scandium complex [(NPN Ph)Sc(CH2SiMe3)2(THF)] in combination with [PhNHMe2][B(C6F5)(4)] and AliBu(3) forms the first non-Cp-ligated rare earth metal based catalyst system to provide extremely high activity and 3,4-selectivity for the polymerization of isoprene. The resultant high molecular weight polymer (M,, = 99 x 104) with narrow molecular weight distribution (PDI = 1.55) has a 3,4-regularity up to 94.7% (Tp = -40 degrees C, toluene, 2 h, 100% yield). The complexes 3b and 3c, with a larger ionic radius, are less regioselective, and 3d, with an electron-donating pyridyl moiety, is inert. The probable initiation species and mechanistic scenario are also presented. |
DOI | 10.1021/om700945r |
Indexed By | SCI |
Language | 英语 |
WOS Research Area | Chemistry |
WOS Subject | Chemistry, Inorganic & Nuclear ; Chemistry, Organic |
WOS ID | WOS:000253268000032 |
Publisher | AMER CHEMICAL SOC |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://ir.imr.ac.cn/handle/321006/126217 |
Collection | 中国科学院金属研究所 |
Corresponding Author | Cui, Dongmei |
Affiliation | 1.Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Polymer Phys & Chem, Changchun 130022, Peoples R China 2.Grad Sch Chinese Acad Sci, Beijing 100039, Peoples R China |
Recommended Citation GB/T 7714 | Li, Shihui,Miao, Wei,Tang, Tao,et al. New rare earth metal bis(alkyl)s bearing an iminophosphonamido ligand. Synthesis and catalysis toward highly 3,4-selective polymerization of isoprene[J]. ORGANOMETALLICS,2008,27(4):718-725. |
APA | Li, Shihui,Miao, Wei,Tang, Tao,Dong, Weimin,Zhang, Xuequan,&Cui, Dongmei.(2008).New rare earth metal bis(alkyl)s bearing an iminophosphonamido ligand. Synthesis and catalysis toward highly 3,4-selective polymerization of isoprene.ORGANOMETALLICS,27(4),718-725. |
MLA | Li, Shihui,et al."New rare earth metal bis(alkyl)s bearing an iminophosphonamido ligand. Synthesis and catalysis toward highly 3,4-selective polymerization of isoprene".ORGANOMETALLICS 27.4(2008):718-725. |
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