Abstract
The effects of a series of small structural changes to (S)-5-nitro-N-(1-phenylethyl)pyridin-2-amine on its solid state non-linear optical properties, including the phenomenon of rotating dielectric axes, have been investigated. Installation of a methyl group in the 3-position of the heterocyclic ring or at the amino nitrogen atom gave the most promising materials, though neither of these materials showed rotating dielectric axes. Details of the crystal structure analyses of a family of these compounds illustrate the delicate interplay between molecular conformation and intermolecular interactions in determining the packing arrangements.