Nature Chem.http://doi.org/hvv (2012)

Credit: © 2012 NPG

Confining reactants in a separate environment to the bulk is a well-established phenomenon in nature that scientists have successfully mimicked in different syntheses. Templated synthesis has also passed from the biological domain to synthetic small-molecule syntheses and polymerizations in recent years. Now, Rachel O'Reilly and colleagues have combined confinement with templating methods to devise a biomimetic approach that achieves unprecedented control over radical polymerization without using living polymerization techniques. This high level of control — which is evident by the low polydispersity (≤1.08) and high molecular weight (up to ∼400,000 g mol−1) of the resultant polymers — is achieved by segregating the propagating radical within discrete micellar cores. The dynamic micelles (pictured) are formed from thymine-containing block copolymers, which template and segregate complementary adenine-containing vinyl monomers inside the cores. The segregation of the radical significantly reduces the bimolecular termination step compared with a similar reaction in bulk solution. This ability to manipulate individual chains by segregation could allow for further control of the polymeric structure, such as the monomer sequence.