Answer:
The unknown compound probably contains a chromophore, which is a structural element that causes a compound to have a specific color. The addition of an oxidizing agent such as chlorine water causes the appearance of a brown color, indicating that the compound contains an electron-rich chromophore. The fact that the organic solvent layer turns purple when the solution is shaken with methylene dichloride suggests that the compound also contains a chromophile, which is a structural element that can form a complex with an electron deficient species like the dichloromethane solvent. The compound probably contains a conjugated system of double bonds, which can act as both chromophore and chromophile, and that is why the color changed from brown to purple after shaking with the organic solvent.