“Link-Functionalized” Polymers:  An Unusual Macromolecular Architecture through Bifunctional Initiation

Abstract

Bimetallic complexes of the type (C5Me5)2Sm−R−Sm(C5Me5)2 were used for the living bis-initiated polymerization of methyl methacrylate and ε-caprolactone, giving polymers with discrete functionalities at the center of the backbone (“link-functionalized”). Poly(methyl methacrylate) containing olefin units was prepared from [(C5Me5)2Sm]2(μ-η3-CH2CHCH−)2 and related allyl compounds, although slow and/or inefficient initiation of polymerization is observed for complexes in which R is a bulky, heteroatom, or coordinating group. In contrast, the polymerization of ε-caprolactone may be carried out with good control in the presence of both sterically hindering and electron-rich moieties. Polylactones incorporating aromatic, cumulene, and amine/imine groups were synthesized through one-step bimetallic initiation in this manner. Differences between lanthanide(III) methacrylate and lactone polymerizations, differences between lanthanide(III) and aluminum(III) lactone polymerizations, and the presence of transesterification in the lactone system are discussed.

New Insights into the Polymerization of Methyl Methacrylate Initiated by Rare‐Earth Borohydride Complexes: A Combined Experimental and Computational Approach

“…, [17] [ [18] or the bis-amido [19,20] act as bifunctional initiators for the polymerization of MMA. Chain-transfer polymerization of MMA mediated by…”

Controlled ring‐opening polymerization of ε‐caprolactone using polymer‐supported scandium catalyst

“…1 Metal complexes are the most commonly explored catalysts; they include tin, 2,3 aluminum, [4][5][6][7] iron, 8,9 scandium, [10][11][12] yittrium, 13,14 zinc, 15,16 bismuth, 17 ruthenium, 18 zirconocene, 19 and so on. A popular polymerization system for PCL is ring-opening polymerization (ROP) of ecaprolactone catalyzed by organotin compound.…”

A Recoverable, Metal-Free Catalyst for the Green Polymerization of ε-Caprolactone

“…Previous examples of metal complexes used as catalysts include tin, 2,6,[15][16][17][18][19][20][21] aluminum, 6,10,18,19,[22][23][24][25][26][27] iron, 6,18 scandium, 1,12,28 yttrium, 14,18,[29][30][31][32][33][34][35] zinc, [36][37][38][39] and other metals. 1,14,18,19,24,25,[30][31][32][33][34][40][41][42][43] Although in a few of these systems the metal com...…”