Ionization and electron excitation of C60 in a carbon nanotube: A variable temperature/voltage transmission electron microscopic study

Abstract

SignificanceThe destruction of specimen molecules by an electron beam (e-beam) is either beneficial, as in mass spectrometry capitalizing on ion formation, or deleterious, as in electron microscopy. In the latter application, the e-beam not only produces the specimen image, but also causes information loss upon prolonged irradiation. However, the atomistic mechanism of such loss has been unclear. Performing single-molecule kinetic analysis of C60 dimerization in a carbon nanotube (CNT) under variable-temperature/voltage conditions, we identified three reactive species-that is, radical cation, singlet, and triplet excited states-reacting competitively as the voltage and the properties of the CNT were changed. The key enabler was in situ continuous recording of the whole reaction process, suggesting an upcoming new era of "cinematic chemistry."