Binuclear Enamino-Oxazolinate Rare-Earth Metal Complexes: Synthesis and Their Catalytic Performance in Isoprene Polymerization.
Inorg Chem
; 63(29): 13358-13366, 2024 Jul 22.
Article
em En
| MEDLINE
| ID: mdl-38946308
ABSTRACT
We have synthesized a series of binuclear rare-earth metal complexes bearing the newly designed enamino-oxazolinate ligands that feature bridging para-phenyl, meta-phenyl, 1,5-naphthalenyl, and 1,5-anthracenyl moieties. NMR and X-ray diffraction analyses confirmed the binuclear structures of the obtained complexes with two enamino-oxazolinate-metal units located at a trans position against the bridged aryl plane. After activation by [Ph3C][B(C6F5)4], all the rare-earth metal complexes served as efficient catalysts for isoprene polymerization, producing polymers with high cis-1,4 regularity (up to 96.1%) and high molecular weight. The steric and electronic effects exerted on the active metal centers, as well as the radius of metal centers, were the major contributing factors for determining both the catalytic activity and cis-1,4-selectivity of the binuclear catalytic systems. Compared to its mononuclear analogue, the binuclear yttrium catalytic system with a para-phenyl bridge exhibited a higher thermostability and catalytic efficiency during polymerization, revealing a special binuclear effect in this binuclear catalytic system.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Inorg Chem
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
China