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New borophosphates Li3Cs2M2B3P6O24 (M = Pb, Sr) have been synthesized by high-temperature solid-state reactions. The single-crystal X-ray diffraction data reveal their non-centrosymmetric cubic space group P213 and lattice parameters of a = 12.7246(3) Å and 12.687(2) Å and V = 2060.31(8) Å3 and 2042.3(4) Å3 for Li3Cs2Pb2B3P6O24 and Li3Cs2Sr2B3P6O24, respectively. They are three-dimensional (3D) [BP2O8]3−∞ anionic frameworks formed by a new double six-membered ring building unit consisting of BO4 and PO4 units joined alternately. Interestingly, such a double six-membered ring is regarded as the structural variation of the 12-membered ring in the known KSrBP2O8, fusing at the BO4 tetrahedron induced by the coexistence of the Li+ and Cs+ cations with their large size difference. The title compounds show weak SHG intensity and exhibit photoluminescence emissions at 410 nm for Li3Cs2Pb2B3P6O24 and 440 nm for Li3Cs2Sr2B3P6O24. [ABSTRACT FROM AUTHOR]

The crystal structure of ethylenediamine dilauroleate was determined by X-ray crystallography. A thermochemical cycle was designed in accordance with Hess law. The enthalpy change of the synthesis reaction of ethylenediamine dilauroleate was determined to be $$ \Updelta_{{\text{r}}} H_{{\text{m}}}^{\Uptheta } $$ = −(49.07 ± 0.11) kJ mol by an isoperibol solution-reaction calorimeter. The standard molar enthalpy of formation of the title compound was calculated to be $$ \Updelta_{\text{f}} H_{\text{m}}^{\Uptheta } $$ = −(38.78 ± 0.43) kJ mol by the designed thermochemical cycle, the enthalpies of dissolution and other auxiliary thermodynamic quantities. [ABSTRACT FROM AUTHOR]

Abstract: Crystal structure of n-decylammonium ethyl sulfate was determined by X-ray crystallography. Lattice potential energy and molar volume of the solid compound and its anion were respectively obtained. Ionic radius of the anion was calculated from the corresponding effective volume of the anion. Molar enthalpies of dissolution of the compound at different concentrations m /(mol·kg–1) were measured by an isoperibol solution–reaction calorimeter at T =298.15K. According to the Pitzer’s electrolyte solution theory, molar enthalpy of dissolution of the compound at infinite dilution () was determined to be (21.284±0.042) kJ·mol–1, and enthalpy of hydration of the anion SO4C2H5 − was calculated to be ΔH– =−340.68kJ·mol–1. The values of apparent relative molar enthalpies ( ΦL) of the title compound and relative partial molar enthalpies ( and ) of the solute and the solvent at different concentrations were derived from experimental values of enthalpies of dissolution of the compound. Finally, enthalpies of hydration of the compound and its anion were calculated by designing a thermochemical cycle in accordance with lattice potential energy and molar enthalpy of dissolution at infinite dilution. [Copyright &y& Elsevier]

The crystal structure of n-undecylammonium bromide monohydrate was determined by X-ray crystallography. The crystal system of the compound is monoclinic, and the space group is P2/ c. Molar enthalpies of dissolution of the compound at different concentrations m/(mol·kg) were measured with an isoperibol solution-reaction calorimeter at T = 298.15 K. According to the Pitzer's electrolyte solution model, the molar enthalpy of dissolution of the compound at infinite dilution ( $$ \Updelta_{\text{sol}} H_{\text{m}}^{\infty } $$) and Pitzer parameters ( $$ \beta_{\text{MX}}^{(0)L} $$ and $$ \beta_{\text{MX}}^{(1)L} $$) were obtained. Values of the apparent relative molar enthalpies ( $$ {}^{\Upphi }L $$) of the title compound and relative partial molar enthalpies ( $$ \bar{L}_{2} $$ and $$ \bar{L}_{1} $$) of the solute and the solvent at different concentrations were derived from experimental values of the enthalpies of dissolution. [ABSTRACT FROM AUTHOR]

Crystal structure of n-undecylammonium bromide monohydrate was determined by X-ray crystallography. Low-temperature heat capacities of the compound were measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 390 K. Two solid–solid phase transitions were observed for the title compound. The temperatures, molar enthalpies, and entropies of the phase transitions were derived based on the analysis of heat–capacity curve. Two polynomial equations of heat capacities as a function of temperature were fitted by least-squares method. Based on the two polynomial equations, smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 K were calculated and tabulated at 5 K intervals. [ABSTRACT FROM AUTHOR]

Abstract: A novel compound n-octanammonium oxalate (C8H17NH3)2C2O4(s) was synthesized by the method of liquid phase reaction. Crystal structure of n-octanammonium oxalate was determined by X-ray crystallography. The lattice potential energy of the compound was calculated to be U POT =1050.90kJ·mol−1. Molar enthalpies of dissolution of the compound at different concentrations m/(mol·kg−1) were measured by an isoperibol solution–reaction calorimeter at T =298.15K. According to the Pitzer’s electrolyte solution theory, the molar enthalpy of dissolution of the compound at infinite dilution () and Pitzer parameters () were obtained. The values of apparent relative molar enthalpies (ΦL ) of the title compound and relative partial molar enthalpies of the solute and the solvent at different concentrations were derived from experimental values of enthalpies of dissolution. The enthalpy change of the synthesis reaction of n-octanammonium oxalate was determined to be by an isoperibol solution–reaction calorimeter, and standard molar enthalpy of formation of (C8H17NH3)2C2O4(s) was calculated to be by using the enthalpies of dissolution and other auxiliary thermodynamic quantities. [Copyright &y& Elsevier]

Abstract: Crystal structures of three long-chain n-alkylammonium dihydrogen phosphates n-C n H2n+1NH3·H2PO4(s) (n=8, 9 and 10) (abbreviated as C8P, C9P and C10P), which may be used as the phase change materials in storage and utilization of solar energy, were determined in layered structures by X-ray crystallography, and the same hydrogen bonding network is observed for these long carbon chain compounds. Low-temperature heat capacities of the compounds were measured by a precision adiabatic calorimeter over the temperature range from 78 to 380K. Two solid–solid phase transitions were observed for C8P and C9P, but only one solid–solid phase transition was observed for C10P. The temperatures, molar enthalpies and entropies of the phase transitions were determined based on the analysis of heat capacity curves. Experimental heat capacities for each compound were fitted to two polynomial equations. The smoothed heat capacities and thermodynamic functions and of the three compounds were calculated with an interval of 10K in terms of the polynomial equations. [Copyright &y& Elsevier]

Abstract: The crystal structure of 1-decylammonium hydrobromide was determined by X-ray crystallography. Lattice potential energy and molar volumes of the solid compound and its cation were obtained respectively. The ionic radius of the cation can be calculated from the corresponding effective volume of the cation. The molar enthalpies of dissolution of the compound at different concentrations m/(mol·kg−1) at T =298.15K were measured by an isoperibol solution-reaction calorimeter at T =298.15K. According to the Pitzer’s electrolyte solution theory, the molar enthalpy of dissolution of the compound at infinite dilution and Pitzer parameters ( and ) were obtained. The values of apparent relative molar enthalpies of the title compound and relative partial molar enthalpies ( and ) of the solute and the solvent at different concentrations were derived from the experimental values of the enthalpy of dissolution of the compound. Finally, hydration enthalpies of the compound and its cation were calculated by designing a thermochemical cycle in accordance with lattice potential energy and the molar enthalpy of dissolution of the title compound at infinite dilution. [Copyright &y& Elsevier]