名称:
Synthesis, characterization, and catalytic activities of rare-earth metal complexes with iminopyrrolyl ligands
摘要:
A series of rare-earth metal complexes with substituted iminopyrrolyl ligands were prepared and characterized. Reactions of [(Me3Si)(2)N](3)Ln(mu-Cl)Li(THF)(3) with 3 equiv. of 2-(2.6-Et2C6H3N CH)C4H3NH (la) in toluene generated tris-iminopyrrolyl rare-earth metal complexes with formula [2-(2,6-Et2C6H3N CH)C4H3N](3)Ln(THF)(n) [n = 0, Ln = Y (2a), Eu (2b); n =1,Ln= Nd (2c), Sm (2d)] in moderate yields. Treatments of [(Me3Si)(2)N](3)Ln(mu Cl) Li(THF)(3) with 3 equiv. of 2-(2,4.6-Me3C6H2N CH)C4H3NH (1b) in toluene afforded tris-iminopyrrolyl rare-earth metal complexes with formula 12-(2,4,6-Me3C6H2N CH)C(4)H(3)NI(3)Ln(THF) [Ln = Y (3a), Sm (3b), Eu (3c)]. The catalytic properties of all rare-earth metal complexes on the ring-opening polymerization of E-caprolactone have been studied. The results represent rare example of the pyrrolyl ligands as initiators for E-caprolactone polymerization. (C) 2011 Elsevier B.V. All rights reserved.