Synthesis, crystal structure and Hirshfeld surface analysis of 1-(4-chlorophenyl)-3-pyrenyl-2-propene-1-one

Abstract

Abstract A new chalcone material 1-(4-chlorophenyl)-3-pyrenyl-2-propene-1-one (PCP) with molecular formula C25H15ClO has been synthesized by Claisen-Schmidt condensation reaction. The newly synthesized chalcone derivative was characterized by elemental analysis and 1H NMR analysis. The sample was purified by repeated recrystallization in acetone solvent and single crystal of the material had been grown by slow evaporation solution growth technique. Single crystal X-ray diffraction analysis has been carried out to determine the crystal structure and to understand the intermolecular interactions. The PCP crystallized in orthorhombic system with noncentrosymmetric space group P212121. The crystal structure consists of a chain of molecules of PCP interconnected by C H…O, C Cl…Cg1 and C H…π interaction running down the b-axis. The two such molecular chains are interconnected by π…π stacking, C H…Cl and C Cl…Cg5 interaction to form a 2D network. These 2D networks are further linked by the C8-H8…π interactions to form a 3D network. The HOMO-LUMO energy gap of PCP is 3.069 eV. The HOMO-LUMO diagram reveals that the intra molecular charge transfer takes place from pyrene moiety to phenyl moiety forming a D -π-A type push-pull molecular system. The material exhibits second harmonic generation property with the SHG efficiency of 6.66 times the standard KDP sample. The C H…π and π…π interactions may be responsible for extending the charge transfer to supramolecular assembly and this could be the reason for high SHG efficiency of PCP in comparison with KDP.