Synthesis and Characterization of Yttrium and Ytterbium Complexes Supported by Salen Ligands and Their Catalytic Properties for rac-Lactide Polymerization

	Synthesis and Characterization of Yttrium and Ytterbium Complexes Supported by Salen Ligands and Their Catalytic Properties for rac-Lactide Polymerization
	Gu, Weikai 1,2; Xu, Pengfei 1,2; Wang, Yaorong 1,2; Yao, Yingming 1,2,3; Yuan, Dan 1,2; Shen, Qi 1,2
刊名	ORGANOMETALLICS
	2015-06-22
卷号	34 期号:12 页码:2907-2916
英文摘要	A series of yttrium and ytterbium complexes supported by Salen ligands with different steric and electronic properties were synthesized, and their catalytic performances for the polymerization of rac-lactide (rac-LA) were explored. The phenol elimination reactions of (ArO)(3)Ln(THF) (ArO = 2,6-Bu-2(t)-4-MeC6H2O) with a number of Salen ligands (CH3)(2)C[CH2N-CH(C6H2-2-OH-3,5-R-2)](2) [(LH2)-H-1, R = H; (LH2)-H-2, R = Cl; (LH2)-H-3, R = Bu-t; L4H2, R = CMe2Ph] and CH2[CH2N-CH(C6H2-2-OH-3,5-Cl-2)](2) ((LH2)-H-5), in a 1:1 molar ratio gave yttrium and ytterbium Salen aryloxides L(1)Ln(OAr)(THF)(2) (Ln = Y (1), Yb (2)), L(2)Ln(OAr)(THF)(n) (Ln = Y (3), n = 2; Ln = Yb (4), n = 1), (LY)-Y-3(OAr) (5), L4Y(OAr)(THF) (6), and L5Yb(OAr)(THF) (7), respectively. The amine elimination reactions of L3H2 with Y[N(SiMe3)(2)](3) in a 1:1 molar ratio and then with 1 equiv of phenol ArOH, and alcohols PhCH2OH and (PrOH)-O-i, produced complex 5 and the yttrium Salen alkoxides [(LY)-Y-3(mu-OCH2Ph)](2) (8) and [(LY)-Y-3(mu-OPri)](2) (9), respectively. X-ray structural determination showed that complexes 14 and 7 have a THF-solvated monomeric structure, and complex 5 has an unsolvated monomeric structure, whereas complex 8 has an unsolvated dimeric structure. All of these complexes can initiate the ring-opening polymerization of rac-LA at 30 degrees C in THF. It was found for the first time that the overall coordination environment around the metal center has an obvious influence on the stereoselectivity of these lanthanide Salen complexes. Five-coordinated complex 5 with bulky tert-butyl substituent groups on the phenyl rings displayed apparently lower stereoselectivity than seven-coordinated complex 1, although there is no substituent on the ortho-positions of the Salen ligand L-1 in the latter. Complex 7 bearing Cl substituents on the Salen ligand showed the highest stereoselectivity among these lanthanide complexes for rac-LA polymerization, and heterotactic polylactides (P-r up to 0.88) can be obtained at 30 degrees C in THF.
收录类别	SCI
语种	英语
公开日期	2015-11-02
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/27928]
专题	化学研究所_高分子物理与化学实验室
作者单位	1.Soochow Univ, Coll Chem Chem Engn & Mat Sci, Key Lab Organ Synth Jiangsu Prov, Suzhou 215123, Peoples R China 2.Soochow Univ, Coll Chem Chem Engn & Mat Sci, Suzhou Key Lab Macromol Design & Precis Synth, Suzhou 215123, Peoples R China 3.Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Polymer Phys & Chem, Changchun 130022, Peoples R China
推荐引用方式 GB/T 7714	Gu, Weikai,Xu, Pengfei,Wang, Yaorong,et al. Synthesis and Characterization of Yttrium and Ytterbium Complexes Supported by Salen Ligands and Their Catalytic Properties for rac-Lactide Polymerization[J]. ORGANOMETALLICS,2015,34(12):2907-2916.
APA	Gu, Weikai,Xu, Pengfei,Wang, Yaorong,Yao, Yingming,Yuan, Dan,&Shen, Qi.(2015).Synthesis and Characterization of Yttrium and Ytterbium Complexes Supported by Salen Ligands and Their Catalytic Properties for rac-Lactide Polymerization.ORGANOMETALLICS,34(12),2907-2916.
MLA	Gu, Weikai,et al."Synthesis and Characterization of Yttrium and Ytterbium Complexes Supported by Salen Ligands and Their Catalytic Properties for rac-Lactide Polymerization".ORGANOMETALLICS 34.12(2015):2907-2916.