Fotóizomerizációja

Fotóizomerizációja refers to the process where a molecule undergoes a change in its geometric structure upon absorbing light. This phenomenon is a type of photochemical reaction. Light energy provides the activation energy needed to overcome the rotational barrier around a double bond or within a ring system, allowing the molecule to rearrange into a different isomer. The most common examples involve the isomerization of cis-trans isomers around carbon-carbon double bonds. For instance, in the visual pigment rhodopsin, light absorption triggers the isomerization of 11-cis-retinal to all-trans-retinal, initiating the cascade of events that lead to vision. Similarly, photochromic materials, which change color upon exposure to light, often rely on photóizomerizációja. The reverse reaction, where the molecule reverts to its original isomer, can occur thermally or also be induced by light of a different wavelength. This reversible nature is crucial for applications like optical data storage and smart windows. The efficiency and wavelength dependence of photóizomerizációja are governed by the specific electronic structure of the molecule.