Atomic force microscopy in the photochemistry of chalcones

The application of atomic force microscopy (AFM) to photodimerization of crystalline chalcones provides new insights into the detailed mechanisms of solid-state reactions on the molecular level. Well-directed long-range transport phenomena are found which reach far beyond the crystal lattice distances. Reactions occur in the surface region where the light is absorbed. Characteristic features are built up that depend on crystal structure and crystal face. This could not be foreseen by previous theories based solely on a topochemical postulate/principle. There is now a much more intimate correlation of crystal structure with solid-state reactivity and this is directly studied and proven experimentally by AFM. Even solid-state reactions which are in opposition to topochemistry can be studied and understood on a molecular basis. The three-dimensional resolution of undisturbed insulating surfaces which is obtained by AFM is not available by any other technique.