Designing of halogenated and traditional donor–acceptors composites for high-performance nonlinear optical applications

Materials having nonlinear optical (NLO) properties have shown hi-tech uses in a variety of modern fields including telecommunications, solid-state physics, laser optics and more recently in quantum computing. The current study offers a comprehensive computational analysis of the chalcone compounds designed through halogens and traditional acceptors. The molecular structure and electronic properties of parent compound (E)-1-(4-aminophenyl)-3-(3-chlorophenyl)prop-2-en-1-one (C1) were quantum chemically simulated and found in good agreement with experimentally reported results. The new chalcone compounds C2–C8 were also proposed by substituting chlorine with acceptors (F, Br, CH₃, CF₃, COOH, CN and NO₂) into a benzene ring with fixed donor (aniline) and a π-bridge (acrolein). DFT and TD-DFT calculations were employed to shed light on charge transfer properties, promising structures, density of states plots and NLO characteristics. The substitution with acceptors effectively modified the structures with halogens and nonhalogen groups, resulting in improved NLO characteristics. A striking NLO response was seen in all proposed compounds. It is interesting to note that the NLO characteristics of C2–C3 and C4–C8 have been significantly improved by the intramolecular charge transfer (ICT) process with β_// value of 18.30 × 10⁻³⁰ esu. However, C7 showed the highest < γ > values of 106.6 × 10⁻³⁶. Among C1–C8 compounds, C8 had a narrower HOMO–LUMO energy gap, facilitating efficient electronic excitations and resonance enhancement which led to an improved NLO response. TDM analysis confirms the intramolecular charge transfer (ICT) in C1–C8 compounds due to the successful migration of charge from donor to acceptor via π-bridge. The current study intrigues scientific interest regarding the formation of chalcone-based appealing NLO compounds that may be useful in recent high-tech applications.

Graphical abstract