Growth and properties of dichloro bis(triphenylphosphine oxide) zinc(II), a novel nonlinear optical crystal

Optical quality single crystals of dichloro bis(triphenylphosphine oxide) zinc(II)(ZnCl2(TPPO)2, TPPO=triphenylphosphine oxide) were successfully grown from ethanol solution by slow evaporation method. The crystal was characterized by single-crystal X-ray diffraction, FTIR spectroscopy, differential scanning calorimetry (DSC), thermal gravity analysis (DTA), and UV–vis–IR spectroscopy. SHG efficiency and laser damage threshold of the crystal were measured. The cutoff wavelength of the crystal was observed to be below 290 nm and the SHG efficiency is 1.5%. The crystal has a high damage threshold of 2.4 GW/cm2. Notably, the ZnCl2(TPPO)2 crystal can reach phase matching of SHG in the visible region.