A novel approach to the synthesis of semiorganic ammonium hydrogen oxalate oxalic acid dihydrate single crystal and its characterization

Abstract

A different approach used in the synthesis of ammonium hydrogen oxalate oxalic acid dihydrate (NH<inf>4</inf>H<inf>3</inf>(C<inf>4</inf>O<inf>8</inf>)·2H<inf>2</inf>O) single crystals is presented. The crystals are synthesized using solvent evaporation technique. The analysis of the synthesized NH<inf>4</inf>H<inf>3</inf>(C<inf>4</inf>O<inf>8</inf>)·2H<inf>2</inf>O single crystals has been carried out through measurements such as single-crystal X-ray diffraction (SCXRD), powder XRD, UV–Vis and photoluminescence spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric and differential thermal analysis (TG–DTA), Vickers microhardness measurements and current versus voltage (I–V) characteristics. The evaluation of the molecular structure of the crystals using SCXRD shows that they belong to the triclinic crystal system with space group P-1. The structural properties of the crystals are also evaluated using powder XRD measurements on their finely crushed powder. These measurements corroborate the results of SCXRD and confirm the triclinic system of the crystals. The optical properties like absorbance and emission of these crystals are determined using UV–Vis and photoluminescence spectroscopy, respectively. These measurements show that the crystals exhibit substantial emission in the blue region. The thermal stability and the decomposition mechanism of the crystals is studied using TG–DTA analysis. The mechanical strength of the crystals is determined using Vickers microhardness technique. The photoresponse of the NH<inf>4</inf>H<inf>3</inf>(C<inf>4</inf>O<inf>8</inf>)·2H<inf>2</inf>O crystals is analyzed from light-dependent I–V characteristics, and it is observed that the crystals exhibit photoresistive behavior. © 2020, Akadémiai Kiadó, Budapest, Hungary.