Second-order optical nonlinearity of two 1,3,4-oxadiazole derivatives: An experimental and theoretical study

Measurements and theoretical modeling of the second-order optical nonlinearity of 2-(4-(dodecyloxy)phenyl)-5-(pyridin-3-yl)-1,3,4-oxadiazole (Oxa-4-Py) and 2-(4-(dodecyloxy)phenyl)-5-(4-(5-(thiophen-2-yl)-1,3,4-oxadia-zol-2-yl)phenyl)-1,3,4-oxadiazole (DiOxaBn-2-Tio) are reported here. The hyper-Rayleigh scattering technique was applied to measure the dynamic first hyperpolarizability, beta lambda=1064 exp , of the samples. The excitation source was a Nd:YAG laser operating at 1064 nm, 6 ns and 10 Hz, and a two-level approximation was applied to estimate the static first hyperpolarizability, beta lambda=0exp, of the samples. The obtained values for exp beta lambda=1064 were 173 x 10-30 esu (Oxa-4-Py) and 226 x 10-30 esu (DiOxaBn-2-Tio), and the calculated values for static first hyperpolarizability, beta lambda=0 exp were 106 x 10-30 esu (Oxa-4-Py) and 126 x 10-30 esu (DiOxaBn-2-Tio). The beta lambda=1064 exp value determined for the DiOxaBn-2-Tio is among the largest experimental values reported so far for a 1,3,4-oxadiazole derivative. The calculations based on a density functional method confirmed the trend of the beta lambda=1064exp values among the samples, i. e. the first hyperpolarizability of DiOxaBn-2-Tio is approximately 30% larger than beta lambda=1064 exp for Oxa-4-Py.

Automated summary

Measurements and theoretical modeling of the second-order optical nonlinearity of two 1,3,4-oxadiazole derivatives, Oxa-4-Py and DiOxaBn-2-Tio, were reported. The dynamic and static first hyperpolarizability values were measured using the hyper-Rayleigh scattering technique and a density functional method. The results showed that the first hyperpolarizability of DiOxaBn-2-Tio is approximately 30% larger than that of Oxa-4-Py.