Spatially-Resolved Multiple Metallopolymer Surfaces by Photolithography

A tetrazole-based photoligation protocol for the spatially-resolved encoding of various defined metallopolymers onto solid surfaces is introduced. By using this approach, fabrication of bi- and trifunctional metallopolymer surfaces with different metal combinations were achieved. Specifically, alpha-omega-functional copolymers containing bipyridine as well as triphenylphosphine ligands were synthesized through reversible addition-fragmentation chain transfer (RAFT) polymerization, and subsequently metal loaded to afford metallopolymers of the widely-used metals gold, palladium, and platinum. Spatially-resolved surface attachment was achieved by means of a nitrile imine-mediated tetrazole-ene cycloaddition (NITEC) based photoligation protocol, exploiting tethered tetrazoles and metallopolymers equipped with a maleimide chain terminus. Metallopolymer coated surfaces with three different metals were prepared and characterized by time-of-flight secondary ion mass spectrometry (ToF-SIMS) and spatially-resolved X-ray photoelectron spectroscopy (XPS) mapping, supporting the preserved chemical composition of the surface-bound metallopolymers. The established photochemical technology platform for arbitrary spatially-resolved metallopolymer surface designs enables the patterning of multiple metallopolymers onto solid substrates. This allows for the assembly of designer metallopolymer substrates.