Vol 2, Chapter 32. Summary Dichroism arises because of the differential interaction of light with molecules which contain a chiral center. Dichroism is not observed unless an absorption band exists. CD spectra of proteins and nucleic acids are much more sensitive to conformational changes than absorption spectra. CD is a reliable method of obtaining -helical content of proteins.
CD is a less reliable method of obtaining sheet content of proteins.
Until now we have been studying the interaction of the transition electric dipole of molecules with the electric field of light. In addition to this interaction, the magnetic field of light can also interact with magnetic transition dipoles . These centers will interact with polarized light. To understand how these two effects occur when polarized light is passed through a sample we will decompose linearly polarized light into right and left circular-polarized light. For the case of E r the electric field vector will rotate in a right hand direction as time passes.