Aryl Radical Addition to Curvatures of Carbon Nanohorns for Single-Molecule-Level Molecular Imaging

Real-time imaging of the dynamics of single molecules and molecular assemblies with atomic-resolution electron microscopy is an emerging experimental methodology to obtain single-molecule-level information on molecular motions and reactions. The central idea of the methodology is to capture single molecules and molecular assemblies in solution with a chemical fishhook and bring them into the nm-scale view field of the electron microscope. We report herein the installation of aromatic groups on carbon nanohorns by the addition of in situ-generated aryl radicals from arylamines selectively to strained areas of positive and negative curvature on the graphitic surface. We can introduce a variety of aromatic moieties including substituted carbo- and heteroaromatics, which can capture molecules from their solution through amide bond formation and van der Waals interaction.