Chirality plays a significant role in the photochemical reactivity of enantiomers. Enantiomers are non-superimposable mirror images of each other and have the same physical and chemical properties, except for their interaction with plane-polarized light and their reactivity with other chiral molecules.The effect of chirality on the photochemical reactivity of enantiomers can be observed in several ways:1. Different absorption of circularly polarized light: Enantiomers can absorb left or right circularly polarized light differently. This phenomenon is known as circular dichroism CD . The difference in absorption can lead to different photochemical reactions or reaction rates for each enantiomer when exposed to circularly polarized light.2. Stereoselective photochemical reactions: When enantiomers undergo photochemical reactions with other chiral molecules, the stereochemistry of the reactants can influence the outcome of the reaction. This can result in the formation of diastereomeric products with different ratios, depending on the chirality of the enantiomers involved. This is known as a stereoselective reaction.3. Stereospecific photochemical reactions: In some cases, the chirality of enantiomers can lead to completely different photochemical reactions or products. This occurs when the reaction pathway is determined by the stereochemistry of the reactant, and each enantiomer follows a different pathway. This is known as a stereospecific reaction.4. Excited-state reactivity: The chirality of enantiomers can also affect their reactivity in the excited state. Upon absorption of light, enantiomers can undergo conformational changes or rearrangements that are influenced by their stereochemistry. This can lead to different excited-state reactivity and ultimately different photochemical products.In summary, the chirality of enantiomers can significantly impact their photochemical reactivity, leading to differences in absorption of circularly polarized light, stereoselective and stereospecific reactions, and excited-state reactivity. These differences are crucial in various applications, such as asymmetric synthesis, chiral separation, and understanding biological processes involving chiral molecules.