Crystal structure, lattice potential energy, and thermochemical properties of a novel compound barium d-gluconate tetrahydrate

• Crystal structure of Ba[d-C6H11O7]2 · 4H2O was determined.
• Lattice potential energy of the compound was calculated.
• Standard molar enthalpy of formation of the compound was calculated.
• The molar enthalpy of dissolution at infinite dilution is determined.

A novel compound barium d-gluconate tetrahydrate, Ba[d-C6H11O7]2 · 4H2O, is synthesized and characterized by chemical analysis, elemental analysis, and X-ray crystallography. Single-crystal X-ray analysis reveals that the compound is formed by two d-gluconate anions, one barium (II) cation and four crystal water molecules. The compound exhibits an outstanding chelate property of d-gluconate anions to barium (II) cations, and the barium (II) cation is ten-coordinated and chelated by six d-gluconate anions. The molecules of the compound are further linked by intermolecular BaO and OH⋯O interactions to form a 3D supramolecular architecture. The lattice potential energy and ionic volume of the anion are obtained from crystallographic data. In accordance with Hess’ law, a reasonable thermochemical cycle is designed and the standard molar enthalpy of formation of Ba[d-C6H11O7]2 · 4H2O(s) is calculated as ΔsHmΔsHm [Ba[d-C6H11O7]2 · 4H2O, s] = −(4712.85 ± 1.06) kJ · mol−1 by use of an isoperibol solution-reaction calorimeter. Molar enthalpies of dissolution of Ba[d-C6H11O7]2 · 4H2O(s) at various molalities are measured at T = 298.15 K in the double-distilled water. According to the Pitzer theory, the molar enthalpy of dissolution of the title compound at infinite dilution is calculated to be ΔsHm∞ = (49.901 ± 1.212) kJ · mol−1. The values of relative apparent molar enthalpies (appH  ), relative partial molar enthalpies of the solvent (H¯1) and the compound (H¯2) at different molalities m/(mol · kg−1) are derived from the experimental values of the enthalpies of dissolution of the compound.

A novel compound barium d-gluconate tetrahydrate, Ba[d-C6H11O7]2 · 4H2O, is synthesized and characterized. The lattice potential energy and ionic volume of the anion are obtained. Standard molar enthalpy of formation is calculated by an isoperibol solution-reaction calorimeter. Molar enthalpies of dissolution at various molalities in the double-distilled water are measured at 298.15 K. According to Pitzer’s theory, molar enthalpy of dissolution of the title compound at infinite dilution is calculated. The values of relative apparent molar enthalpies, relative partial molar enthalpies of the solvent and the compound at different concentrations m/(mol · kg−1) are derived from the experimental values of the enthalpies of dissolution of the compound.Figure optionsDownload as PowerPoint slide