The photochemical properties of enantiomers can differ due to their chiral nature, which means they are non-superimposable mirror images of each other. This chirality can lead to differences in the way enantiomers interact with light, specifically with the polarization of light. The molecular mechanisms behind these differences are mainly due to the spatial arrangement of atoms in the enantiomers and their interaction with the electric field of light.1. Circular Dichroism CD : Circular dichroism is a phenomenon where enantiomers absorb left and right circularly polarized light differently. This difference in absorption can be measured as a CD spectrum, which is unique for each enantiomer. The molecular mechanism behind CD is the interaction of the chiral molecule with the electric and magnetic fields of the circularly polarized light. The spatial arrangement of the atoms in the enantiomers determines the strength and direction of these interactions, leading to differences in the CD spectra.2. Optical Rotation: Optical rotation is the rotation of the plane of linearly polarized light as it passes through a solution of chiral molecules. Enantiomers can rotate the plane of polarized light in opposite directions, with one enantiomer causing a clockwise rotation dextrorotatory and the other causing a counterclockwise rotation levorotatory . The molecular mechanism behind optical rotation is the interaction of the chiral molecule with the electric field of the linearly polarized light. The spatial arrangement of the atoms in the enantiomers determines the strength and direction of these interactions, leading to differences in the optical rotation.3. Photochemical Reactions: The photochemical properties of enantiomers can also differ in terms of their reactivity under light exposure. For example, one enantiomer might undergo a specific photochemical reaction more readily than its mirror image. This can be due to differences in the excited-state energy levels and geometries of the enantiomers, which can affect the efficiency of the photochemical reaction pathways.In summary, the photochemical properties of enantiomers can differ due to their chiral nature, which affects their interaction with light and their photochemical reactivity. The molecular mechanisms behind these differences are mainly due to the spatial arrangement of atoms in the enantiomers and their interaction with the electric and magnetic fields of light.