KLi(HC3N3O3)·2H2O: Solvent-drop Grinding Method toward the Hydro-isocyanurate Nonlinear Optical Crystal.

A novel mixed alkali hydro-isocyanurate, KLi(HC3N3O3)·2H2O was first prepared in AOH-BOH-H3C3N3O3 (A/B = Li/Na/K/Rb/Cs) system via a solvent-drop grinding method. KLi(HC3N3O3)·2H2O shows a large second harmonic generation response (5.3 × KH2PO4) with an ultraviolet cutoff edge of 237 nm. More importantly, the bulk single crystal can be readily grown through water solution technique. Characterization of these crystals indicates that KLi(HC3N3O3)·2H2O has a high laser damage threshold (LDT) (4.76 GW/cm2) and exhibits a large birefringence (Δ n = 0.186@514 nm), which reduces Type I phase-matching to 246 nm.