Synthesis and third-order optical nonlinearities of ferrocenyl Schiff base

► Four ferrocenyl Schiff bases were designed and synthesized. ► The third-order nonlinear optical properties were measured using DFWM. ► The third-order susceptibilities of the compounds were 2.21-3.32 × 10−13 esu. ► The second-order hyperpolarizabilities of the molecules were 2.10-3.15 × 10−31 esu. ► The response times were 42-63 fs.