Synthesis, spectroscopic, structural elucidation, NLO characteristic and Hirshfeld surface analysis of (E)-1-(4-ethylphenyl)-3-(4-(heptyloxy) phenyl)prop-2-en-1-one: A dual approach of experimental and DFT calculations

Abstract Single crystal of (E)-1-(4-ethylphenyl)-3-(4-(heptyloxy)phenyl)prop-2-en-1-one (4EPC) was grown in acetonitrile via slow evaporation solution technique. The molecular structure of 4EPC was then confirmed by single crystal X-ray diffraction analysis and the crystal exhibited monoclinic with centrosymmetric space group of C2/c. The synthesised molecule of 4EPC was fully characterized using spectroscopic techniques by Fourier-Transform infrared (FT-IR) spectroscopy, Nuclear Magnetic Resonance (1H and 13C NMR), thermal stability analysis via Thermogravimetric analysis (TGA) and electronic transitions through UV–visible analysis. In addition, the theoretical investigations on its electronic properties via UV–vis analysis of 4EPC was calculated using time-dependent TD-DFT B3LYP/6-31G (d, p) level of theory. As predicted, the experimental results were complimentary to the theoretical findings. The Hirshfeld surface analysis contributes to the study in the aspect of the nature of intermolecular interactions as well as fingerprint plots which gave the information on the percentage contribution from each individual contact. Molecular electrostatic potential (MEP) analysis provides an initial information on the charge concentration throughout the molecule 4EPC which designated the possible interaction site to occur. Moreover, the nonlinear optical (NLO) properties of 4EPC was calculated to gain further understanding on the possibility of developing this compound as NLO material. Calculated NLO results found that the polarizability and 1st order hyperpolarizability of 4EPC is −2.13 × 10−23 esu and 1.27 × 10−30 esu respectively which is greater than the value of 1st order hyperpolarizability of urea (β = 0.372 × 10−30 esu). The high values obtained from the calculated NLO were due to the dipole, molecular alignment and also from the non-covalent interaction within crystal of 4EPC which can be developed further as potential organic light emitting diode application.