A double-site Lewis pair for highly active and living synthesis of sulfur-containing polymers

This work describes an organic double-site Lewis pair with exceedingly high activity for the copolymerization of carbonyl sulfide (COS) with propylene oxide (PO). Fully alternating poly(monothiocarbonate)s can be produced with >99% regioregularity in a living manner. Molecular weight of the copolymers can be tuned in the range of 3.8–103.1 kg mol⁻¹ (PDI: 1.09–1.18). Importantly, the on–off character of this system was also investigated and proved to be an effective way to regulate the copolymerization and synthesize block copolymers.