Simultaneously recorded photochemical action plots reveal orthogonal reactivity.

We map the photochemical reactivity of two chromophores-a pyrene-chalcone and a methylene blue protected amine-from a one-pot reaction mixture based on their dynamic absorptivity changes upon light exposure, constructing a dual action plot. We employ the action plot data to determine a pathlength-independent λ-orthogonality window, allowing the orthogonal folding of distinct polymer chains into single chain nano-particles (SCNPs) from the same reaction mixture.

Red light induced folding of single polymer chains.

We pioneer the photochemical generation of single chain nanoparticles (SCNPs) at the to-date mildest reported wavelength of 625 nm by exploiting the photochemical uncaging of methylene blue protected amines. The protected amines are tethered to polymers prepared via reversible addition-fragmentation chain transfer (RAFT) polymerisation, and subsequently undergo intrachain crosslinking by amide formation.