Investigation of Second-Order Nonlinear Optical Properties of Push-Pull Chromophores on a Salicylate Scaffold

Abstract

The development of photonic devices relies significantly on the creation of organic materials showing substantial second-order nonlinear optical (NLO) responses. This work investigates the salicylate scaffold, supported by an intramolecular hydrogen bond, as a highly promising yet underutilized platform for the design of high-performance chromophores. Six derivatives (AZ1–AZ6) were theoretically modeled by DFT to assess geometry, frontier molecular orbitals, dipole moments, and static first hyperpolarizability (β_tot). The results show that there is a discernible structure–property relationship: the nitro-substituted derivative (AZ3) had the strongest intramolecular charge transfer (ICT) with the largest β_tot, outperforming the standard para-nitroaniline. These results identify the salicylate framework as a promising blueprint for the design of next-generation NLO materials.