The Effects of Conjugated Fused Ring System: An Investigation of Electronic, Nonlinear Optical, X-Ray Structural Properties and Computational Studies on Chalcone Derivatives

The conjugated fused ring system of chalcone with D-A-π-A and A-A-π-D framing has been the subject of a detailed study on intramolecular charge transfer (ICT). The strong donors (Anthracene and Pyrene), strong acceptors (cyano), and large extended conjugation are in charge for the higher third order susceptibility in order of (10−6 esu) and show good optical limiting behavior with a lower optical limiting threshold which is determined by Z-scan analysis. Computational studies reveal that the higher values of dipole moments, polarizability and second hyperpolarizability values provided evidence that the proposed compounds are suitable as an efficient NLO material. The band gap energy generated from the FMOs was shown to be decreasing while μ increased, which is an indication of ICT occurring within molecules. Natural bond orbital (NBO) studies the different ICT interactions occurring and demonstrated a significant push-pull action for both compounds, with donor (pyrene and anthracene) and negative values for acceptors. The study of single-crystal X-ray diffraction shows the packing arrangements positioned side by side enhance the intermolecular charge transfer between the donor and the acceptor group of the molecules. Based on our experimental and theoretical findings, we can conclude that the studied compounds exhibit potential in NLO applications such as optical limiting devices.