Growth and characterization of some oxalic acid based nonlinear optical single crystals

Abstract

In recent years, Nonlinear Optical (NLO) materials have been studied extensively for their potential applications. Oxalic acid is an organic compound including two carboxyl groups (-COOH). The presence of dipoles in the oxalic acid allows the compound to contribute energetically appropriate hydrogen bonding. Besides, oxalic acid is very reactive in solution due to the delocalization of the electron in the C=O bond. Crystals of oxalic acid derivatives are possible candidates for nonlinear optical applications. In the present work, single crystals of oxalate compounds have been synthesized from its aqueous solution using slow evaporation solution growth technique. newlineSingle crystals of Potassium Hydrogen Oxalate (KHO) are grown by slow evaporation solution growth technique at room temperature using double distilled water as the solvent. The grown crystals are subjected to various characterization techniques. The monoclinic structure with space group P21/c of the KHO single crystal has been confirmed by Single Crystal X-ray Diffraction (SXRD) technique. The crystal packing is ruled by extensive networks of hydrogen bonds revealed by the detailed study of the refinement of the crystal structure by a full-matrix least square method using SHELXL software. Optical transparency of the crystal in the entire visible region has been confirmed by Ultraviolet Visible-Near Infrared (UV-Vis-NIR) analysis. newline