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

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.

Reaction mechanism to achieve (nitrovinyl)-1H-pyrazole structure exhibiting 58 and 67 GM absorption cross-section at 520 and 690 nm wavelengths, respectively and first hyper polarizability 45 × 10−30 cm5/esu.Figure optionsDownload as PowerPoint slideHighlights
► Nonlinear optical properties of newly synthesized (nitrovinyl)-1H-pyrazole explored.
► fs Z-scan technique used for 2PA cross-section spectrum in 460–780 nm range.
► 2PA exhibits two bands with cross-sections of 58 (520 nm) and 67 GM (690 nm).
► Experimental βHRS (45 × 10−30 cm5/esu) estimated by ps hyper-Rayleigh scattering.
► Theoretical calculations (MP2/6-311+G(d) yield similar value 40 ± 2 × 10−30 cm5/esu.