Theoretical and vibrational studies of 4,5-diphenyl-2-2 oxazole propionic acid (oxaprozin)

The molecular structure, linear and nonlinear optical properties, and electronic properties of 4,5-diphenyl-2-2 oxazole propionic acid (oxaprozin) as a monomer were investigated by using Hartree–Fock (HF) and density functional theory (DFT) calculations that used 6-31G(d,p) basis set. The first-order hyperpolarizability of oxaprozin (OXA) was found to be 1.117 × 10−30 esu. The structure of oxaprozin dimer with HF/6-31G(d) level caused by the shifts of O–H and CO bands in the vibrational spectra of oxaprozin were also studied. Moreover, these calculated frequencies of oxaprozin dimer were compared with the solid FT-IR and FT-Raman spectra. The theoretical frequencies and infrared intensities were showed a good agreement with experimental data.