Mol­ecular structure, DFT studies and Hirshfeld analysis of anthracenyl chalcone derivatives

The mol­ecular and crystal structure of two new chalcone derivatives, (E)-1-(anthracen-9-yl)-3-[4-(piperidin-1-yl)phen­yl]prop-2-en-1-one, C(28)H(25)NO, (I), and (E)-1-(anthracen-9-yl)-3-[4-(di­phenyl­amino)­phen­yl]prop-2-en-1-one, C(35)H(25)NO, (II), with the fused-ring system at the same position are described. In the crystals of (I) and (II), the mol­ecules are linked via C—H⋯O hydrogen bonds into inversion dimers, forming R (2) (2)(22) and R (2) (2)(14) ring motifs, respectively. Weak inter­molecular C—H⋯π inter­actions further help to stabilize the crystal structure, forming a two-dimensional architecture. The mol­ecular structures are optimized using density functional theory (DFT) at B3LYP/6–311 G++(d,p) level and compared with the experimental results. The smallest HOMO–LUMO energy gaps of (I) (exp . 2.76 eV and DFT 3.40 eV) and (II) (exp . 2.70 eV and DFT 3.28 eV) indicates the suitability of these crystals in optoelectronic applications. All inter­molecular contacts and weaker contributions involved in the supra­molecular stabilization are investigated using Hirshfeld surface analysis. The mol­ecular electrostatic potential (MEP) further identifies the positive, negative and neutral electrostatic potential regions of the mol­ecules.