Ring-opening polymerization of lactides using heterobimetallic yttrocene complexes

Citation
K. Beckerle et al., Ring-opening polymerization of lactides using heterobimetallic yttrocene complexes, MACRO CH P, 200(7), 1999, pp. 1702-1707
Citations number
24
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
MACROMOLECULAR CHEMISTRY AND PHYSICS
ISSN journal
10221352 → ACNP
Volume
200
Issue
7
Year of publication
1999
Pages
1702 - 1707
Database
ISI
SICI code
1022-1352(199907)200:7<1702:RPOLUH>2.0.ZU;2-5
Abstract
Structurally characterized, chiral heterobimetallic yttrocene derivatives L i[Y(eta(5):eta(1)-C5R4SiMe2NCH2CH2OMe)(2)] (R = Me, H) have been shown to b e active in the controlled ring-opening polymerization of L-lactide to give poly(L-lactide)s with high molecular weights and moderately narrow molecul ar weight distributions ((M) over bar(w)/(M) over bar(n) < 1.50). Both tran sesterification and racemization appear to be less prominent. H-1 NMR spect roscopic tetrad analysis of copolymers prepared using a mixture of L- and D -lactide demonstrates the absence of any preference for one enantiomer duri ng the polymerization.