Cooperative
catalysis is a powerful strategy in the catalytic ring-opening
copolymerization of epoxides and CO2, especially for breaking
through the dependence of the polymer selectivity on the temperature
and the restriction of the activity by catalyst concentration. In
this work, to realize multisite cooperativity in a homogeneous catalysis,
a series of oligomer catalysts flexibly bearing aluminum(III) porphyrin
complexes in the side chains were synthesized by reversible addition–fragmentation
chain transfer (RAFT) polymerization. The catalytic performance distinctly
outperformed that of the previous molecular metal catalyst under identical
conditions: (1) a 3–5-fold increase in activity was observed
as approximately four to seven Al centers were anchored in one catalyst
chain; (2) the required use of a cocatalyst was reduced by 50–75%
(3) 99% polymer selectivity was achieved even at 90 °C; (4) the
activity was maintained at a very low catalyst loading ([Al]/PO =
1/100 000), with the number-average molecular weight of the
resulting copolymer above 200 kg/mol.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.