Second Harmonic Generation in Λ-Shaped Organic Molecules

Abstract

In epoxy based polymeric nonlinear optical (NLO) materials, the nonlinear optically active moiety forms crosslink between polymer chains. Some of the important moieties include 4, 4 diamino diphenyl sulfone (DADS). We have examined second harmonic generation (SHG) in DADS and have compared it with 4, 4 diamino diphenyl methane (DADM). The geometry optimization suggests that both molecules have Λ-shaped structure. The theoretical calculations as well as experimental observations of SHG in both the molecules suggest the suitability of DADS over DADM for making polymeric NLO materials.

The Role of Polar, Lamdba (Λ)-Shaped Building Units in Noncentrosymmetric Inorganic Structures

“…The Λ shape is important for the design of BBUs without an inversion center and for packing of the BBUs into an NCS environment. Chemists have tailored organic and hybrid materials to Λ-shaped BBUs, as they have a high probability of packing into NCS crystals. ,,,− For Λ-shaped organic molecules, such as N , N ′-bis­(4-ethoxycarbonylphenyl)­methaneiamin, minimization of intermolecular hydrogen bonds causes a preference for stacking of Λ-shaped units and synthesis of an NCS crystal structure . Similarly, our group has previously reported that minimizing contacts to the oxide ligand can lead to NCS, polar structures .…”