Spectroscopic characterization and structural insights of 4-[(1E)-3-(4-methoxyphenyl)-3-oxoprop-1-en-1-yl] phenyl 4-methylbenzene-1-sulfonate using vibrational, electronic spectra and quantum chemical calculations

In this work, a chalcone derivate 4-[(1E)-3-(4-methoxyphenyl)-3-oxoprop-1-en-1-yl] phenyl 4-methylbenzene-1-sulfonate (hereafter named as 4MPMS) is examined through spectroscopic experiments and quantum chemical methods to explore the vibrational features, electronic transitions and non-linear optical (NLO) properties. The normal coordinate analysis was implemented to predict the contributions of various normal modes at the desired frequencies of IR and Raman spectra and the spectral peaks were assigned accordingly. A static second-order and third-order hyperpolarizabilities of 4MPMS were predicted and the molecule's vibrational and electronic contributions to the NLO activity were analyzed. Also, certain properties such as the HOMO-LUMO energy gap, charge delocalization, and other quantum descriptors that are associated with the chemical reactivity and NLO response of the molecule were explained. Density functional theory (DFT) with B3LYP/6–311(d,p) level of theoretical approximation was used.