Photochemical behavior of diheteroarylethenes and photochromism

This chapter deals with the photochromism of diheteroarylethenes. The phenomenon is framed in the more general context of photochemistry, through an initial treatment of basic theoretical aspects of photochemistry. This chapter specifically addresses the theme of photochromism in heteroarylethenes. The structural modifications of the ethene bridge and of the heteroaryl groups are treated for interpreting the trends observed in the various properties of these class of compounds such as the quantum yield of photocyclization and the stereochemistry of the process. A brief overview of important applications in modern technological field is also present.