Synthesis and Characterization of Semiorganic Potassium Hydrogen Oxalate Oxalic Acid Dihydrate Single Crystals

Abstract

A metal-organic hybrid compound named potassium hydrogen oxalate oxalic acid dihydrate (KHOOD) single crystal is synthesized using solvent evaporation technique at room temperature. Synthesized crystals are thoroughly characterized using various methods such as single crystal XRD (SCXRD), powder XRD (PXRD), UV-vis analysis, FTIR, TGA-DTA, DSC, photoluminescence, Vickers microhardness, SEMEDAX, I-V and dielectric measurements. The synthesized crystal belongs to centrosymmetric space group P-1 with triclinic crystal system and from I-V studies negative photoconductivity effect is observed suggesting their use as photoresistors. Further, doping studies were carried out for the synthesized KHOOD crystals where, commercially purchased Amaranth dye and pre-synthesized Co(OH)2 nanoparticles were used for doping KHOOD single crystals. The presence of Co(OH)2 nanoparticles in the crystal system were confirmed through XRD, EDAX and PL measurements. The effect of nanoparticle incorporation on the optical, thermal and electrical properties of the crystals were studied with the help of UV-vis, TGA-DTA, I-V and dielectric measurements. From I-V and dielectric measurements it was confirmed that the conductivity increases as the dopant concentration increased. Influence of amaranth dye on the KHOOD single crystal was also investigated. The effect of dye molecule on the crystal of KHOOD was studied using XRD, UV-vis, SEM-EDX, PL, TGA-DTA and I-V measurements. The defect induced studies were performed for different dosage of Gamma irradiations. The structural, optical and electrical properties of the irradiated crystals were studied and results were analyzed. The effect of irradiation on the crystal lattice for different dosage was investigated. As the irradiation dosage increased, the crystal conductivity decreases which consequently led to increase in its resistivity which is also true in case of light irradiated crystals. Further, a detailed study is conducted to understand the differences between Oxalic acid dihydrate (OAD), Potassium oxalate hydrate (KOH), Potassium hydrogen oxalate oxalic acid dihydrate (KHOOD) for comparing their physical properties. The crystals of these compounds were studied using PXRD, UV-vis, PL, TGA-DTA, I-V and Vickers microhardness studies to understand the physio chemical changes brought about by the complexation of the oxalic acid.