Investigation of geometric, spectroscopic and optical properties of 3,5-dimethylpyrazolinium picrate molecule by theoretical methods

Keywords: 3,5-Dimethylpyrazolinium picrate, DFT, HSEH1PBE, B3LYP 1H and 13C NMR, IR, UV-Vis, NLO and NBO analysis. In this study, theoretical calculations were made on 3,5-Dimethylpyrazolinium picrate (DMPP) molecule using B3LYP/6-311++G(d,p) and HSEH1PBE/6-311++G(d,p) methods. For this purpose, its ground state geometric structure, vibration spectrum, ultraviolet absorption spectrum, 1H and 13C NMR chemical shift values were calculated and compared with the previously performed experimental study results. Total energy, HOMO and LUMO energies of complex compound were calculated and its chemical hardness and softness properties were examined. Natural bond orbital (NBO) analysis was performed to investigate intramolecular charge transitions. Dipole moment, mean polarizability, anisotropy of polarizability and first order hyperpolarizability parameters were calculated in order to investigate the NLO properties of the compound. According to the obtained theoretical data, it was found that the compound is a good candidate for NLO material. In addition, refractive index and extinction coefficients as well as real and imaginary dielectric constants were calculated using ultraviolet absorption and transmittance spectra. Molecular electrostatic potential surface of the compound was calculated and used to determine the electrophilic and nucleophilic reaction sites. Gaussian-09W, GaussView-5 and Swizard programs were used for all calculations.