Synthesis and characterization of symmetrical benzodifuranone compounds with femtosecond time-resolved degenerate four-wave mixing technique

We synthesized four symmetrical benzodifuranone compounds. Their structures were confirmed by UV, IR, 1H NMR and elemental analysis. The off-resonant third-order nonlinear optical properties of the compounds were investigated via femtosecond time-resolved degenerate four-wave mixing technique with 80 fs pulse width at 800 nm. The third-order nonlinear optical susceptibilities X(3) were 2.86–3.21 × 10−13 esu. The nonlinear refractive index n2 were 5.26–5.91 × 10−12 esu. The second-order hyperpolarizabilities γ of the molecules were 2.92–3.42 × 10−31 esu. The response times were 88–91 fs. These results show that symmetrical benzodifuranone compounds have potential nonlinear optical applications.