Experimental and theoretical investigation of optical nonlinearities in (nitrovinyl)-1H-pyrazole derivative

Abstract

This work reports on the optical nonlinearities of a newly synthesized pyrazole derivative, namely (E)-1-(4-chlorophenyl)-4-(2-nitrovinyl)-1H-pyrazole. The Z-scan technique with femtosecond laser pulses was used to determine the two-photon absorption (2PA) cross-section spectrum, which presents a maximum of 67 GM at 690 nm. We have combined hyper-Rayleigh scattering (HRS) experiments and second-order Møller–Plesset perturbation theory (MP2) calculations to study the first hyperpolarizability (βHRS). It was found that the MP2/6-311+G(d) model, taking into account solvent and dispersion effects, provides the βHRS value of 40 × 10−30 cm5/esu for the compound, in good agreement with the experimental result of 45 ± 2 × 10−30 cm5/esu.