Control of supramolecular organization by molecular structure and symmetry leading to the induction and enhancement of solid state SHG

We describe novel molecular level approaches to the induction and enhancement of solid state second harmonic generation (SHG) capability in molecular materials based on the 4-nitroaniline moiety. Introduction of optimally long alkyl chains leads to the induction of optical SHG capability. Under appropriate crystallization conditions, a C 2 -symmetric derivative possessing moderate hyperpolarizability assembles into helical superstructures through nitro group interactions and show enhanced solid state SHG.