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A novel coordination compound rubidium d-gluconate Rb[d-C6H11O7](s) has been synthesized and characterized by chemical analysis, elemental analysis, and X-ray diffraction. Single-crystal X-ray analysis reveals that the crystal is monoclinic with space group P21 and Z = 2. Also, the d-gluconate anion in Rb[d-C6H11O7](s) has a bent-chain conformation, in which the carbon atoms of the anion form two approximate planes. The compound exhibits an obvious chelation of the d-gluconate anions to the rubidum(I) cation and the cation is seven-coordinated to all seven oxygen atoms. The lattice potential energy and ionic volume of the anion d-C6H11O7- were obtained to be UPOT = 484.23 kJ·mol−1 and V− = 0.2004 nm3 from crystallographic data. Molar enthalpies of dissolution of Rb[d-C6H11O7](s) in double-distilled water at various molalities were measured by use of an isoperibol solution-reaction calorimeter at T = 298.15 K. According to Pitzer’s electrolyte solution model, the molar enthalpy of dissolution of the title compound at infinite dilution was determined to be ΔsHm∞=(29.76±0.72)kJ·mol-1. The values of the apparent relative molar enthalpies (ϕL) of the title compound and relative partial molar enthalpies (L¯2 and L¯1) of the solute and the solvent at different concentrations were derived from the experimental enthalpies of dissolution of the compound. Furthermore, the molar enthalpy of hydration of the anion d-C6H11O7- was calculated to be ΔH− = − (166.4 ± 2.7) kJ·mol−1 by use of a thermochemical cycle. [ABSTRACT FROM AUTHOR]

An important coordination compound potassium d-gluconate K[d-C6H11O7](s) has been synthesized by liquid phase method. The chemical component and crystal structure of the important compound are characterized by chemical analysis, elemental analysis, and X-ray crystallography. Single-crystal X-ray analysis reveals that the compound exhibits the chelate property of d-gluconate anions to K+ cations, a six-membered chelate ring is formed by the coordination of K+ with O2 of carboxylate and O4 of hydroxyl in a d-gluconate, and one cation is coordinated to six d-gluconate anions. The lattice potential energy and ionic volume of the anion [d-C6H11O7]− are obtained from crystallographic data. In accordance with Hess’ law, a reasonable thermochemical cycle is designed according to the practical synthesis reaction of the compound and the standard molar enthalpy of formation of the compound is calculated to be −(1754.17 ± 0.19) kJ mol−1 as an important physical quantity in chemical thermodynamics by an isoperibol solution–reaction calorimeter. Molar enthalpies of dissolution of the compound at various molalities are measured at T = 298.15 K in the double-distilled water. According to Pitzer’s electrolyte solution theory, molar enthalpy of dissolution of the title compound at infinite dilution is calculated to be ΔsHm∞ = (27.92 ± 0.21) kJ mol−1. In terms of the above value, the standard molar enthalpy of formation of the anion [d-C6H11O7]− in the aqueous solution is determined to be  = −(1473.87 ± 0.28) kJ mol−1. The values of relative apparent molar enthalpies (ΦL) and relative partial molar enthalpies of the solvent (L¯1) and the compound (L¯2) at different concentrations m/(mol kg−1) are derived from the experimental values of the enthalpies of dissolution of the compound. [ABSTRACT FROM AUTHOR]

The sodium d-gluconate Na[ d-CHO](s) has been synthesized and characterized by elemental analysis and X-ray crystallography. X-ray single-crystal analysis reveals that the compound exhibits an obvious chelate property of d-gluconate anions to sodium cation, and the latter is coordinated to six d-gluconate anions. The lattice potential energy of the compound and ionic volume of the d-gluconate anion are obtained from crystallographic data. In accordance with law of Hess, a reasonable thermochemical cycle is designed and the standard molar enthalpy of formation of the compound Na[ d-CHO](s) is determined to be −(1472.68 ± 0.48) kJ mol by use of an isoperibol solution-reaction calorimeter. Molar enthalpies of dissolution of Na[ d-CHO](s) at various molalities are measured at T = 298.15 K in the double-distilled water. According to Pitzer's electrolyte solution theory, molar enthalpy of dissolution of the title compound at infinite dilution is determined to be (23.783 ± 0.128) kJ mol. [ABSTRACT FROM AUTHOR]

Abstract: Sodium benzoate was synthesized by the method of liquid phase synthesis, in which benzoic acid and anhydrous sodium carbonate were chosen as the reactants. The structure and composition of the compound were characterized by FTIR, chemical analysis, elemental analysis and X-ray powder diffraction techniques. Low temperature heat capacities of the compound were measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400K. A polynomial equation of the heat capacities as a function of the temperature was fitted by least square method. The smoothed heat capacities and the thermodynamic functions of the compound relative to 298.15K have been calculated based on the equation. In accordance with Hess law, the standard molar enthalpy of formation of the title compound C6H5COONa (s) was determined to be by using an isoperibol solution-reaction calorimeter. [Copyright &y& Elsevier]

Abstract: Benzoic acid and concentrated ammonia were chosen as reactants and a novel compound (ammonium benzoate) was synthesized using the method of liquid phase reaction. FTIR, elemental analysis and X-ray powder diffraction technique were applied to characterize the structure and composition of the compound. Low-temperature heat capacities of the solid compound were measured by a precision automated adiabatic calorimeter over the temperature range from 80 to 399K. A polynomial equation of the heat capacities was fitted by the least-squares method. In accordance with Hess’ law, a thermochemical cycle was designed, the enthalpy change of the reaction of benzoic acid with ammonium acetate was determined as , and the standard molar enthalpy of formation of the compound was calculated as by an isoperibol solution–reaction calorimeter. [Copyright &y& Elsevier]

Abstract: A novel complex, bis(trans-bis(N,N-dimethyl-(1-(R)-phenyl-2-(S)-methyl-2-aminoethoxy-N,O))-copper(II)) heptahydrate (abbreviated as Cu2(C11H16NO)4·7H2O(cr)), was synthesized by the method of liquid phase reflux. The composition and structure of the complex were characterized by chemical analysis, elemental analysis, FTIR, and X-ray crystallography. A reasonable thermochemical cycle was designed based on the preparation reaction of the coordination compound, and standard molar enthalpies of dissolution of reactants and products were measured by an isoperibol solution-reaction calorimeter. Finally, the standard molar enthalpy of formation of the complex Cu2(C11H16NO)4·7H2O(cr) was determined to be −(4525.22±13.71)kJ·mol−1 in accordance with Hess’s law. [ABSTRACT FROM AUTHOR]

Abstract: Ethylenediamine dihydrochloride (C2H10N2Cl2)(s) was synthesized. The crystal structure of the compound has been determined by X-ray crystallography. The lattice potential energy and ionic radius of the cation of the compound were obtained from the crystallographic data. Molar enthalpies of dissolution of the compound in double-distilled water under various values of molality were determined at T =298.15K by an isoperibol solution-reaction calorimeter. Following to Pitzer’s theory, the molar enthalpy of dissolution of the compound at infinite dilution and the Pitzer parameters ( and were obtained. The values of relative apparent molar enthalpies (ΦL ), relative partial molar enthalpies of the compound and relative partial molar enthalpies of the solvent at different concentrations m/(mol·kg−1) were derived from the experimental values of the enthalpies of dissolution of the compound. Finally, the hydration enthalpy of the cation of the substance was calculated by designing a thermochemical cycle. [Copyright &y& Elsevier]