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.