Real-Time Imaging of Platinum−Sulfur Ligand Exchange Reactions at the Single-Molecule Level via a General Chemical Technique

A powerful fluorescence technique for imaging individual covalent-bond-forming events in diverse chemical reactions is reported. The generality originates from employing the fluorophore as a spectator rather than a chemical reaction partner. This spectator technique was used to image individual ligand exchange reactions between platinum complexes and sulfur in real time. The chemical reactions were imaged on a key industrial catalyst support, a siloxy-modified surface, providing insight about reactivity distribution on these surfaces. Such reactivity distribution information is not available via traditional solution ensemble techniques, which average the properties of billions of molecules, or via AFM measurements, which provide information about the topology of the surface. Using superlocalization techniques, the positions of individual chemical reactions on the surface were localized below the diffraction limit, with a positional accuracy of up to ±11 nm.