Communications Chiral Vicinal Bis(amide) Molecules: Polar/Helical Assemblies in Crystals and Second Harmonic Generation

A family of organic and metal-organic materials based on chiral vicinal bis(amide) structures are developed. Subtle molecular structure variations give rise to polar and helical organizations in crystals of the two basic compounds N,N'-bis(benzoyl)-(1R,2R)-diaminocyclohexane and N,N'-bis(isonicotinoyl)-(1R,2R)-diaminocyclohexane; they exhibit the unusual syn and normal anti conformations of the bis(amide) group, respectively. The new materials exhibit appreciable thermal stability and optical transparency. Trends in their second harmonic generation capability are analyzed.