3,4-Polymerization of Isoprene by Using NSN- and NPN-Ligated Rare Earth Metal Precursors: Switching of Stereo Selectivity and Mechanism

	3,4-Polymerization of Isoprene by Using NSN- and NPN-Ligated Rare Earth Metal Precursors: Switching of Stereo Selectivity and Mechanism
	Liu, Bo ; Li, Lei ; Sun, Guangping ; Liu,Jingyao ; Wang,Meiyan ; Li,Shihui ; Cui,Dongmei
刊名	macromolecules
	2014
卷号	47 期号:15 页码:4971-4978
关键词	3 1 COMPLEXES BEARING PROPYLENE POLYMERIZATION OLEFIN POLYMERIZATION CONJUGATED DIENES ALKYL COMPLEXES SYNDIOSPECIFIC COPOLYMERIZATION SYNDIOTACTIC 1 STEREOSPECIFIC CATALYST 4-SELECTIVE LIVING POLYMERIZATION 3-DIENE POLYMERIZATION 2-POLYBUTADIENE
通讯作者	cui,dm
英文摘要	the rare-earth metal complexes bearing nsn-bidentate beta-diimidosulfonate ligands (rnsndipp)ln-(ch2sime3)(2)(thf)(n) (r = ph, ln = lu (1a), n = 1, y (1b), n = 2, sc (1c), n = 1; r = phnme2, ln = lu (1d), n = 1) were synthesized by treatment of the ion-pairs [ln(ch2sime3)(2)(thf)(x)][bph4] with equimolar amount of the ligand lithium salts (rnsndipp)li(thf)(2) (nsndipp = s((nc6h4pr2)-pr-i-2,6)(2)). addition reaction between lutetium tris(alkyl)s, ln(z)(3)(thf)(n) and nsndipp gave the corresponding dialkyl complexes (znsn(dipp))lu(z)(2)(thf)(n) (z = ch2sime3, n = 1 (le); z = o-ch2c6h4nme2, n = 0 (1f)). deprotonation of beta-imidophosphonamido ligands h-npndipp and h-npndipp (npndipp = ph2p(nc(6)h(3)(i)pr2-2,6)(2), npnet = pph2((nc6h3pr2)-pr-i-2,6)(nc6h4-et-2)) with lu(ch2sime3)(3)(thf)2 yielded the corresponding dialkyl complexes (npndipp)lu(ch2sime3)(2)(thf) (2) and (npnet)lu(ch2sime3)(2)(thf) (3). all the complexes had been structurally well-defined, and 1a, 1b, 1e, 2, and 3 were further characterized by x-ray diffraction analysis where the almost planar nsn rare-earth metal unit is c-s (or pseudo c-s) symmetry with the two alkyl groups arranging on both sides and a coordinated thf against it. upon activation with [phme2nh][b(c6f5)(4)] and (albu3)-bu-i, all these complexes exhibited high 3,4-regioselectivity (ranging from 91% to >99%) for the polymerization of isoprene. moreover, the excellent isospecific selectivity up to mmmm > 99% have been achieved with complexes 1 depending on the electronics of the sulfur substituents to give crystalline polyisoprene with the highest t-m (170 degrees c) reported to date. the npn-bidentate beta-imidophosphonamide ligated rare-earth metal complexes provide both high syndio- and iso- 3,4-selectivities (3,4 > 99%, rr = 66%, mmmm = 96%) depending on the frameworks, steric environment and geometry of the ligands. the regio- and stereo- selective mechanisms proceeded in these systems were explicated by dft simulation.
收录类别	SCI
语种	英语
WOS记录号	WOS:000340350400015
内容类型	期刊论文
源URL	[http://ir.ciac.jl.cn/handle/322003/52091]
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, Bo,Li, Lei,Sun, Guangping,et al. 3,4-Polymerization of Isoprene by Using NSN- and NPN-Ligated Rare Earth Metal Precursors: Switching of Stereo Selectivity and Mechanism[J]. macromolecules,2014,47(15):4971-4978.
APA	Liu, Bo.,Li, Lei.,Sun, Guangping.,Liu,Jingyao.,Wang,Meiyan.,...&Cui,Dongmei.(2014).3,4-Polymerization of Isoprene by Using NSN- and NPN-Ligated Rare Earth Metal Precursors: Switching of Stereo Selectivity and Mechanism.macromolecules,47(15),4971-4978.
MLA	Liu, Bo,et al."3,4-Polymerization of Isoprene by Using NSN- and NPN-Ligated Rare Earth Metal Precursors: Switching of Stereo Selectivity and Mechanism".macromolecules 47.15(2014):4971-4978.