Magnetic chiroptical effects in second harmonic reflection on an isotropic film of chiral molecules

Summary form only given. Surface second harmonic generation on a film of chiral molecules is an efficient way to probe their optical activity. However, the importance of the magnetic contribution to these nonlinear chiroptical effects is not well understood yet. We have performed such measurements where the magnetic contributions are clearly evidenced. The organic molecules we study have delocalized electrons to enhance the second order hyperpolarizability, and an asymmetric carbon to allow for optical activity. An optically flat silica substrate is immersed in an ethanol solution of a pure enantiomer, to obtain a thin isotropic film. The UV-visible spectrum exhibit an absorption structure centered at 385 nm, with a maximum optical density of 0.015.