Electron microscopic observation of selective excitation of conformational change of a single organic molecule.

Atomic resolution transmission electron microscopic observations at different electron acceleration voltages enabled us to observe visually the energy relaxation process of one conformer into another via rotation of various parts of the molecule. Cross-correlation analysis of sequential transmission electron microscopy (TEM) images or of the difference between experimental and simulated TEM images has been utilized for investigation of the conformational mobility and for structure identification of conformers.