Two new nickel(II) complexes: Synthesis and third-order optical nonlinearity

Two new nickel(II) complexes were synthesized and characterized by UV, MS and elemental analysis. Their off-resonant third-order nonlinear optical properties were measured using femtosecond laser and degenerate four-wave mixing technique. The third-order nonlinear optical susceptibilities χ⁽³⁾ are 3.38 × 10^?13 esu and 3.64 × 10^?13 esu. The nonlinear refractive index n₂ are 6.22 × 10^?12 esu and 6.70 × 10^?12 esu. The second-order hyperpolarizabilities γ of the molecules are 3.38 × 10^?31 esu and 3.65 × 10^?31 esu. The response times are 61 fs and 74 fs. The results show that the two complexes have potential nonlinear optical applications.