Crystal growth of semiorganic sodium p-nitrophenolate dihydrate from aqueous solution and their characterization

Sodium p-nitrophenolate dihydrate (NPNa·2H2O), is a semiorganic nonlinear optical crystal which is reported to have an effective nonlinear optical coefficient of 5 pm/V. The crystal is usually grown from methanol. By suitably varying the growth parameters, we obtained stable, transparent, sodium p-nitrophenolate dihydrate using water as a solvent. Large single crystals of the dimension 20×17×8 mm3 were grown by a temperature-lowering method. Preliminary characterizations were carried out on the grown sample and compared with methanol-grown NPNa·2H2O. The optical transmission study on these crystals revealed that the crystals grown from aqueous solution have a higher percentage of transmission, thereby favourably affecting optical performance.