Plenty of Room at the Top: A Multi-Scale Understanding of nm-Resolution Polymer Patterning on 2D Materials.

Lamellar phases of alkyldiacetylenes in which the alkyl chains lie parallel to the substrate represent a straightforward means for scalable 1-nm-resolution interfacial patterning. This capability has the potential for substantial impacts in nanoscale electronics, energy conversion, and biomaterials design. Polymerization is required to set the 1-nm functional patterns embedded in the monolayer, making it important to understand structure-function relationships for these on-surface reactions. Polymerization can be observed for certain monomers at the single-polymer scale using scanning probe microscopy. However, substantial restrictions on the systems that can be effectively characterized have limited utility. Here, using a new multi-scale approach, we identify a large, previously unreported difference in polymerization efficiency between the two most widely used commercial diynoic acids. We further identify a core design principle for maximizing polymerization efficiency in these on-surface reactions, generating a new monomer that also exhibits enhanced polymerization efficiency.