Vibrational spectra of (4E)-4-((E)-3-phenyl-allylideneamino)-1,2-dihydro-2,3-dimethyl-1-phenylpirazol-5-one

This work presents through the X-ray diffraction method the crystal structure of ((4E)-4-((E)-3-phenyl-allylideneamino)-1,2-dihydro-2,3-dimethyl-1-phenylpirazol-5-one (C20H19N3O) as well as its vibrational properties and DFT calculations. The crystal is monoclinic with a = 13.487 إ, b = 9.788 إ, c = 13.836 إ and the space group P21/n ( C 2 2 ). The equilibrium geometries, harmonic frequencies, infrared intensities and Raman scattering activities were calculated by density functional B3LYP method with the 6-31 G(d,p) basis set. The comparison between the calculated and experimental results covering molecular structure and, assignments of fundamental vibrational modes were investigated. The optimized molecular geometries have been compared with the experimental data obtained from XRD data, which indicates that the theoretical results agree well with the corresponding experimental values. For the compound, comparisons and assignments of the vibrational frequencies indicate that the calculated frequencies are close to the experimental data.