Relating the crystal structure and third-order nonlinear susceptibility of a new Neolignan derivative

Abstract

Theoretical results for electronic properties of a synthesized nitro chalcone with a neolignan moiety (NOPP) whose crystal structure was elucidated by using Single Crystal X-ray Diffraction (SCXRD) are presented. The NOPP crystal structure suggests that its potential for nonlinear applications is related to the chalcone moiety planarity and that the lamellar NOPP crystal packing along with dimer formation maximize the electronic properties. The in-crystal absorption spectrum and static and dynamic electric properties were determined by applying a supermolecule approach in combination with an iterative electrostatic scheme, in which the surrounding molecules are represented by point charges. It is found that the environment polarization effect is mild for absorption spectrum and linear polarizability, but it is marked for second hyperpolarizability of NOPP molecule. Estimates of macroscopic quantities from the results of an explicit unit cell of crystal, including environment polarization effect and partially the exchange and dispersion effects, are presented. The results illustrate the role played by these interactions on the third-order nonlinear susceptibility of the NOPP crystal, and a theoretical (λ=532nm) prediction of 2.81×10−20 (m/V)2 for χ(3)(−ω;ω,ω,ω) suggests that the NOPP crystal is a very promising NLO material.