Cinematographic imaging and analysis of the electron beam-induced formation of an endohedral metalloporphyrin-fullerene hybrid

Abstract

The bottom-up synthesis of strained hollow cage structures, such as fullerenes, using traditional thermal or photochemical methods remains one of the most challenging tasks in organic chemistry. Here, we demonstrate the synthetic use of an electron beam by in-depth single-molecule atomic resolution time-resolved transmission electron microscopy studies to induce the formation of an elusive doubly-holed fullerene-porphyrin cage structure from a well-defined benzoporphyrin precursor deposited on graphene. Through real-time imaging, we analyze the hybrid's peculiar ability to host up to two Pb atoms and subsequently gain insights into the dynamics of the Pb–Pb binding motif in this exotic metallo-organic cage structure. Through density functional theory calculations and image simulations, we conclude that the much slower secondary electrons, which accumulate in the irradiated area's periphery, can also initiate chemical reactions. Consequently, designing advanced carbon nanostructures by e-beam lithography will depend on the understanding and limitations of molecular radiation chemistry.