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Controlled ring‐opening polymerization of ε‐caprolactone initiated by in situ formed yttrium trisalicylaldimine complexes, and their study by density functional theory
Author(s) -
Ni Xufeng,
Liang Zhenhua,
Ling Jun,
Li Xue,
Shen Zhiquan
Publication year - 2011
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.3145
Subject(s) - polymerization , tetrahydrofuran , ring opening polymerization , yttrium , steric effects , density functional theory , caprolactone , polymer chemistry , ring (chemistry) , molar mass distribution , ligand (biochemistry) , materials science , chemistry , computational chemistry , organic chemistry , polymer , oxide , biochemistry , receptor , solvent
A series of yttrium trisalicylaldimine complexes formed in situ by the reaction of trialkyl complex [Y(CH 2 SiMe 3 ) 3 (THF) 2 ] (THF is tetrahydrofuran) with three equivalent salicylaldimines were used as initiators for the ring‐opening polymerization of ε‐caprolactone. Electronic and steric effects of the salicylaldimine ligand played important roles on the catalytic properties of the yttrium complexes. The yttrium trisalicylaldimine complex Y( L7 ) 3 ( L7 = (S)‐2,4‐di‐ tert ‐butyl‐6‐[(1‐phenylethylimino)methyl]phenol) most effectively initiated controlled ring‐opening polymerization of ε‐caprolactone to prepare poly(ε‐caprolactone)s with high molecular weights and moderate molecular weight distributions. Obtained by density functional theory calculations, the optimized geometries of the four different active centers with four salicylaldimine ligands explained the experimental results. Copyright © 2011 Society of Chemical Industry