Structural, Spectroscopic (UV-Vis and IR), Electronic and Chemical Reactivity Studies of (3,5-Diphenyl-4,5-dihydro-1H-pyrazol-1-yl)(phenyl)methanone

(3,5-Diphenyl-4,5-dihydro-1H-pyrazol-1-yl)(phenyl)methanone (DPPPM) was synthesized using a rapid and recyclable reaction media of polyethylene glycol-400 (PEG-400) and catalytic amount of acetic acid. This method gives remarkable advantages such as a simple workup and a greener method by avoiding hazardous and toxic solvents. The computational calculations for the title compound were carried out using the density functional theory (DFT) method with B3LYP hybrid functional and 6-311++G(d,p) basis set. The structural parameters like bond lengths, bond angles, and dihedral angles were obtained from the optimized molecular geometry and discussed. This structural analysis shows that the DPPPM molecule has a non-planar structure and possess C1 point group symmetry. The infrared vibrational spectral bands assignments were made by correlating experimental findings with the computed data that showed a good agreement. The electronic spectral properties were explored using the time-dependent DFT in the gas phase and two different polarity solvents. The theoretical UV-Vis absorption results obtained were in an acceptable agreement with the UV-Vis absorption experimental results. The solvent effect on wavelength of absorption was also reported. The frontier molecular orbital, molecular electrostatic surface potential and global chemical reactivity parameters for the title molecule in the gas phase were reported and discussed. Based on the results, the synthesized molecule possesses a good strength and kinetic stability.