Design Strategy of Highly Efficient Nonlinear Optical Orange?Colored Crystals with Two Electron?Withdrawing Groups

A new class of highly efficient nonlinear optical organic salt crystals is reported. In optics based on materials, it well known that using two electron-withdrawing groups (EWGs) onto cationic electron acceptors instead conventional one EWG remarkably enhances microscopic nonlinearity for chromophores. However, the corresponding possessing enhanced large macroscopic have not been reported yet. Herein, a design strategy proposed obtaining EWGs in acceptors. Introducing phenolic donor, promoting head-to-tail interionic assembly, along with two-EWG N-pyrimidinyl pyridinium acceptor chromophores results preferred non-centrosymmetric, perfectly parallel alignment crystal. Newly designed OPR (4-(4-hydroxystyryl)-1-(pyrimidin-2-yl)pyridinium) exhibit approximately times larger effective first hyperpolarizability than analogous N-alkyl OHP (4-(4-hydroxystyryl)-1-methylpyridinium) only EWG. comparable second-order to benchmark red-colored DAST (4-(4-(dimethylamino)styryl)-1-methylpyridinium 4-methylbenzenesulfonate) crystals, but significant blue-shifted absorption resulting orange-color crystals. Therefore, are promising materials various applications.