Single-Molecule Reactor Based on the Excluded Volume Effect of Bottlebrush Polymers

Precise spatiotemporal control of chemical reactions, as in living organisms, is a longstanding challenge in chemistry. Herein, we develop a bottlebrush polymer reactor (BBPR), which is a simple yet versatile single-molecule reactor consisting of a bottlebrush polymer that can spatially confine various polymerization reactions. The dense side chains of bottlebrush polymers generate a strong excluded volume effect (EVE) that effectively prevents reactions between the backbone chains of individual BBPRs. However, BBPRs allow the intrusion of small molecules and linear polymer chains. BBPRs can confine two distinct polymerization reactions, namely, ring-opening metathesis polymerization and Suzuki-Miyaura polymerization, without significant inter-reactor coupling reactions. The BBPR concept offers flexibly adjustable confinement spaces, selective permeability, and facile product release, providing a new paradigm for precision control of chemical reactions.