Achiral lanthanide alkyl complexes bearing N,O multidentate ligands. Synthesis and catalysis of highly heteroselective ring-opening polymerization of rac-lactide

	Achiral lanthanide alkyl complexes bearing N,O multidentate ligands. Synthesis and catalysis of highly heteroselective ring-opening polymerization of rac-lactide
	Liu XL ; Shang XM ; Tang T ; Hu NH ; Pei FK ; Cui DM ; Chen XS ; Jing XB
刊名	organometallics
	2007
卷号	26 期号:10 页码:2747-2757
关键词	GROUP-3 METAL-COMPLEXES CYCLIC ESTER POLYMERIZATION RACEMIC LACTIDE SINGLE-SITE STEREOSELECTIVE POLYMERIZATION EPSILON-CAPROLACTONE POLY(LACTIC ACID) 1-HEXENE POLYMERIZATION COORDINATION CHEMISTRY ETHENE POLYMERIZATION
ISSN号	0276-7333
通讯作者	cui dm
中文摘要	alkane elimination reactions of amino-amino-bis(phenols) h2l1-4, salan h2l5, and methoxy-beta-diimines hl6,7 with lanthanide tris(alkyl) s, ln(ch2sime3)(3)(thf)(2) (ln = y, lu), respectively, afforded a series of lanthanide alkyl complexes 1-8 with the release of tetramethylsilane. complexes 1-6 are thf-solvated mono( alkyl) s stabilized by o, n, n, o-tetradentate ligands. complexes 1-3 and 5 adopt twisted octahedral geometry, whereas 4 contains a tetragonal bipyramidal core. bearing a monoanionic moiety l-6 (l-7), complex 7 ( 8) is a thf-free bis(alkyl). in complex 7, the o, n, n-tridentate ligand combined with two alkyl species forms a tetrahedral coordination core. complexes 1, 2, and 3 displayed modest activity but high stereoselectivity for the polymerization of rac-lactide to give heterotactic polylactide with the racemic enchainment of monomer units p-r ranging from 0.95 to 0.99, the highest value reached to date. complex 5 exhibited almost the same level of activity albeit with relatively low selectivity. in contrast, dramatic decreases in activity and stereoselectivity were found for complex 4. the salan yttrium alkyl complex 6 was active but nonselective. bis(alkyl) complexes 7 and 8 were more active than 1-3 toward polymerization of rac-la, however, to afford atactic polylactides due to di-active sites. the ligand framework, especially the "bridge" between the two nitrogen atoms, played a significant role in governing the selectivity of the corresponding complexes via changing the geometry of the metal center.
收录类别	SCI
语种	英语
WOS记录号	WOS:000246027300038
公开日期	2010-07-13
内容类型	期刊论文
源URL	[http://ir.ciac.jl.cn/handle/322003/14037]
专题	长春应用化学研究所_长春应用化学研究所知识产出_期刊论文
推荐引用方式 GB/T 7714	Liu XL,Shang XM,Tang T,et al. Achiral lanthanide alkyl complexes bearing N,O multidentate ligands. Synthesis and catalysis of highly heteroselective ring-opening polymerization of rac-lactide[J]. organometallics,2007,26(10):2747-2757.
APA	Liu XL.,Shang XM.,Tang T.,Hu NH.,Pei FK.,...&Jing XB.(2007).Achiral lanthanide alkyl complexes bearing N,O multidentate ligands. Synthesis and catalysis of highly heteroselective ring-opening polymerization of rac-lactide.organometallics,26(10),2747-2757.
MLA	Liu XL,et al."Achiral lanthanide alkyl complexes bearing N,O multidentate ligands. Synthesis and catalysis of highly heteroselective ring-opening polymerization of rac-lactide".organometallics 26.10(2007):2747-2757.