Study on the nonlinear optical properties of substituted ketene N,S-acetals

A series of substituted ketene N,S-acetals containing tiny π conjugation system with various electron donors and acceptors have been synthesized through the reaction between substituted ketene S,S-acetals and substituted anilines. The maximum and cut-off absorption wavelengths of the synthesized acetals range around 310–360 and 400–420 nm, respectively. The first order hyperpolarizability (β) of the synthesized acetals was determined with Hyper-Rayleigh scattering in solution and solvatochromism. The results show that some synthesized acetals possess higher β values which are close to that of p-NA. To combine the analyses of crystal structure, powder second harmonic generation (SHG) efficiency and d33 value of doped films in PMMA, it suggests that some synthesized acetals may be the promising blue-light transparent nonlinear optical (NLO) materials for application to frequency doubling of semiconductor laser.