Polymerization within a molecular-scale stereoregular template

Enzymes efficiently synthesize biopolymers by organizing monomer units within regularly structured molecular-scale spaces and exploiting weak non-covalent interactions, such as hydrogen bonds, to control the polymerization1 process. This ‘template’ approach is both attractive and challenging for synthetic polymer synthesis, where structurally regulated molecular-scale spaces could in principle provide solid-phase reaction sites for precision polymerization. Previously, free-radical polymerization of methyl methacrylate in solutions containing stereoregular isotactic (it) or syndiotactic (st) poly(methyl methacrylate) (PMMA) has been shown to result in template synthesis2,3 of the opposite PMMA based on stereocomplex formation4,5 with van der Waals interactions. However, using the structure of a solid to determine the stereochemical structure of a polymer has not been satisfactorily achieved6. Here we show that macromolecularly porous ultrathin films, fabricated by a single assembly step, can be used for the highly efficient stereoregular template polymerization of methacrylates through stereocomplex formation. This reaction mould accurately transfers its structural properties of stereoregularity, molecular weight and organization within the template to the new polymer.