Crystal structure, spectroscopic characterization and DFT study of two new linear fused-ring chalcones

The structures of two new anthracenyl chalcones, namely (E)-1-(anthracen-9-yl)-3-(4-nitro-phen-yl)prop-2-en-1-one, C₂₃H₁₅NO₃, and (E)-1-(anthracen-9-yl)-3-(4-iodo-phen-yl)prop-2-en-1-one, C₂₃H₁₅IO are reported. A structural comparative study between the two chalcones was performed and some effects on the geometrical parameters, such as planarity and dihedral angles, are described. The mol-ecular geometry was determined by single-crystal X-ray diffraction, and density functional theory (DFT) at B3LYP with the 6-311++G(d,p) basis set was applied to optimize the ground-state geometry. In addition, inter-molecular inter-actions responsible for the crystal packing were analysed. The electronic properties, such as excitation energies and HOMO-LUMO energies were calculated by time-dependent density functional theory (TD-DFT) and the results complement the experimental findings. The mol-ecular electrostatic potential (MEP) was also investigated at the same level of theory in order to identify and qu-antify the possible reactive sites.