Electronic, reactivity and third order nonlinear optical properties of thermally-stable push-pull chalcones for optoelectronic interest: Experimental and DFT assessments

The present work highlighted the integration of quantum chemical approach and experimental results in attempts to elucidate the structural-property characteristics and behaviour of the fused-aromatic chalcones on the impact of their nonlinear attribute at the molecular level. Two push-pull chalcones namely 1-(anthracen-9-yl)-3(9-ethyl-carbazol-3-yl)prop-2-en-1-one (1AECP) and 3(9-ethyl-carbazol-3-yl)-1(pyren-1-yl)prop-2-en-1-one (3ECPP) were successfully designed, synthesised and analysed through FT-IR, UV–Vis, 1D NMR, TGA, DSC and third-order optical nonlinearities were performed via Z-scan measurement. Concurrently, density functional theory (DFT) analysis with basis set of B3LYP/6-31G (d,p) was computed to optimize the most stable molecular geometry configuration, HOMO-LUMO energy gap, global chemical reactivity descriptors (GCRD), molecular electrostatic potentials (MEP), natural bond orbital (NBO) analysis and hyperpolarizability analyses. The experimental optical gap (Egopt) of both compounds has demonstrated good agreement with corresponding calculated result and fall in the range of organic semiconducting materials with low range of HOMO-LUMO energy gap values, 2.98 and 2.74 eV respectively. The DFT result revealed that fused-aromatic reinforce intramolecular charge transfer (ICT), electronic dipole moment and improve polarizabilities on NLO properties of the material. The thermal stability analysis pinpointed that both of these materials are able to withstand high temperature up to 300 °C which unintentionally unveil their encouraging performance potentially. Additionally, Z-scan analysis discovered that both of the targeted compounds are indeed nonlinear refraction (NLR) active, manifesting self-defocusing effect with n2 value of −1.75 x 10−9 esu (1AECP) and −1.75 x 10−8 esu (3ECPP). In short, the theoretical output complement the experimental results fundamentally in the evaluation and prediction of their electronic nature which hence proved their prospect essentially in the optoelectronic-manufacturing development.