Release Time:2019-03-13  Hits:

Indexed by: Journal Article

Date of Publication: 2016-07-27

Journal: POLYHEDRON

Included Journals: Scopus、SCIE

Volume: 113

Page Number: 50-54

ISSN: 0277-5387

Key Words: Yttrium complex; Amidinate ligand; Polymerization; C-H bond activation; Catalyst

Abstract: The treatment of half-metallocene dialkyl yttrium complexes (C5Me4SiMe3)Y(CH2SiMe3)(2)(THF) (1a) and (C5Me4SiMe2Ph)Y(CH2SiMe3)(THF) (1b) with carbodiimide (RN=C=NR, R = Bu-t, Cy, Pr-i) resulted in two different kind of yttrium complexes bearing bis(amidinate) ligands. The reaction of complex la gave THF-free monoalkyl complexes (C5Me4Me3Si)Y(CH2SiMe3)[(RN)(2)C(CH2SiMe3)] (2a-c) as thermally robust crystals, while the reaction of complex 1b resulted in an ortho-metalated product 3, which contains a strained five-membered chelate ring formed by the C-H bond activation of the phenyl group. All resulted complexes were fully characterized by NMR spectroscopy and the structures of complexes 2a and 3 were confirmed by X-ray diffraction. Complexes 2a-2c show low to high activities for n-butyl acrylate polymerization to produce high molecular weight polymers. (C) 2016 Elsevier Ltd. All rights reserved.