Third-order nonlinear optical properties of three chlorinated thienyl chalcones derivatives: synthesis, structural determination and Hirshfeld surface analysis
Abstract Three chlorinated theinyl chalcone derivatives, namely (E)-1-(5-chlorothiophen-2-yl)-3-(4-(methylthio)phenyl)prop-2-en-1-one (I), (E)-1-(5-chlorothiophen-2-yl)-3-(4-(dimethylamino)phenyl)prop-2-en-1-one (II) and (E)-1-(5-chlorothiophen-2-yl)-3-(2,3-dihydrobenzofuran-5-yl)prop-2-en-1-one (III), were synthesized and their crystal structures were determined by single-crystal X-ray diffraction analysis. Compounds I, II and III crystallize in the monoclinic space groups P 21/c (centrosymmetric), P 21/n (centrosymmetric) and Pc (non-centrosymmetric), respectively. In all three compounds, the molecules are in a relatively planar conformation and adopt a trans configuration with respect to the C=C double bond. The crystal packings are stabilized by weak hydrogen-bonds, π · · · π, C–H · · · π and C–Cl · · · π interactions. The intermolecular contacts and lattice energies were further analyzed by Hirshfeld surface analysis. The third-order nonlinear optical properties of these chalcone derivatives were investigated using the single beam Z-scan technique with a 5 mW continuous wave diode laser operating at 635 nm, where compound I showed the highest potential for optical application with its exclusive nonlinear refractive index and nonlinear susceptibility.