The photodegradation of an organic molecule under UV light irradiation involves the absorption of light energy by the molecule, leading to the excitation of its electrons and subsequent chemical reactions that break down the molecule into smaller fragments or photoproducts. The mechanism can be explained in several steps:1. Absorption of UV light: When the organic molecule absorbs UV light, its electrons are excited from their ground state to a higher energy level. This process creates an excited state molecule, which is more reactive than the ground state molecule.2. Excited state reactions: The excited state molecule can undergo various reactions, such as bond cleavage, rearrangement, or interaction with other molecules. These reactions can lead to the formation of radicals, ions, or other reactive species.3. Radical reactions: Radicals are highly reactive species that can react with other molecules or with themselves, leading to the formation of new products. In the case of photodegradation, radicals can cause the breakdown of the organic molecule into smaller fragments.4. Formation of photoproducts: The reactions of the excited state molecule, radicals, and other reactive species lead to the formation of various photoproducts. These products can be stable or unstable, and they may undergo further reactions or degradation under continued UV light exposure.The possible photoproducts formed during the photodegradation of an organic molecule depend on the specific structure and functional groups present in the molecule. Some common photoproducts include:1. Smaller organic molecules: Photodegradation can lead to the cleavage of the parent molecule into smaller organic fragments.2. Oxygen-containing products: If the organic molecule contains oxygen or reacts with oxygen during the degradation process, oxygen-containing products such as alcohols, aldehydes, ketones, or carboxylic acids may form.3. Nitrogen-containing products: If the organic molecule contains nitrogen, nitrogen-containing products such as amines, amides, or nitriles may form.4. Halogen-containing products: If the organic molecule contains halogens, halogen-containing products such as haloalkanes or haloaromatics may form.5. Inorganic products: In some cases, the photodegradation process may lead to the formation of inorganic products such as carbon dioxide, water, or nitrogen gas.To predict the specific photoproducts formed during the photodegradation of a particular organic molecule, one needs to consider the molecule's structure, functional groups, and the possible reactions that can occur upon UV light absorption. Additionally, experimental studies and computational modeling can help to identify and characterize the photoproducts formed during the photodegradation process.