Fotokromofori

Fotokromofori are molecules that undergo a reversible change in color upon exposure to light. This phenomenon is known as photochromism. The color change is a result of a change in the molecule's structure, which alters its absorption spectrum. Typically, photochromic molecules exist in two stable or metastable forms, with different colors. When exposed to light of a specific wavelength, the molecule transitions from one form to the other, resulting in a visible color change. This process can be reversed by exposing the molecule to light of a different wavelength, or by thermal energy.

The mechanism behind this transformation usually involves the breaking and reforming of chemical bonds, leading to a rearrangement of the molecule's electron system. Common classes of photochromic compounds include spiropyrans, diarylethenes, and azobenzenes. These molecules find applications in various fields due to their light-sensitive nature. Examples include photochromic lenses in eyeglasses, which darken in sunlight and become clear indoors, and in optical data storage, where information can be written and erased using light. They are also explored for use in smart windows, security inks, and molecular switches. The reversibility and controllability of the color change make fotokromofori attractive for applications requiring dynamic optical properties.