Experimental and Computational Investigations on the Molecular Structure, Vibrational Spectra, Electronic Properties, FMO and MEP Analyses of 4,6-Bis(4-Fluorophenyl)-5,6-dihydropyrimidin-2(1H)-one: A DFT Insight

In the present work 4,6-bis(4-fluorophenyl)-5,6-dihydropyrimidin-2(1H)-one was synthesized by condensation of (2E)-1,3-bis(4-fluorophenyl)prop-2-en-1-one with urea in basic medium. The synthesized compound was characterized by using FT-IR and 1H NMR spectroscopic techniques. To determine the molecular structure of synthesized molecule some quantum chemical calculations were carried out by density functional theory (DFT) with employing B3LYP level at 6-311++G(d,p) basis set in gas phase, water and CCl4 solvents by using Gaussian-03 package. The optimized geometrical parameters, thermochemical parameters and global reactivity descriptors have been computed. The frontier molecular orbital (FMO) and molecular electrostatic potential (MEP) analysis also performed to explore the reactivity of title molecule at same level of theory. The vibrational frequencies of title molecule were analysed and compared with the corresponding experimental data. The results show fair correlation between the calculated frequencies in gas phase and experimental frequencies. The effect of water and CCl4 solvents on vibrational frequencies and global chemical reactivity descriptors were also examined. Obtained results show that polar solvent water decreased the carbonyl stretching frequency largely while other frequencies in water and CCl4 are slightly different than gas phase. There is no significant change by solvents were observed on energy gap (∆E) and global reactivity descriptors of studied molecule.